fix(ffi): eliminate aliasing UB + add Azure Policy JSON compilation FFI (#727)

* fix(ffi): eliminate aliasing UB via to_shared_ref migration

Add to_shared_ref() helper that creates &T (shared reference) from raw
pointers instead of &mut T. This eliminates undefined behavior caused by
violating Rust's aliasing invariant when C# SafeHandle permits concurrent
FFI calls on the same handle.

With &mut T, the compiler may assume exclusive (noalias) access and
reorder or elide reads/writes — a miscompilation risk when another thread
holds a reference to the same object. Switching to &T removes that
assumption; actual mutation is mediated by the interior RwLock inside
Handle<T>, which is the sole synchronization mechanism.

Migrated sites:
- rvm.rs: 20 non-drop call sites
- engine.rs: 30 non-drop call sites + with_unwind_guard for timer fns
- compiled_policy.rs: 2 call sites
- Fix null-data UB in regorus_program_deserialize_binary

Drop paths retain to_ref() where exclusive access is guaranteed by the
caller contract (preventing use-after-free).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* feat(ffi): add Azure Policy JSON compilation FFI and C# bindings

- AliasRegistry builder pattern: RegorusAliasRegistryBuilder (mutable,
  single-threaded) + RegorusAliasRegistry (immutable, Arc-wrapped)
- Azure Policy JSON compilation: regorus_compile_azure_policy_rule and
  regorus_compile_azure_policy_definition with alias registry support
- regorus_rvm_set_context for host-supplied ambient data
- C# AliasRegistryBuilder and AliasRegistry classes with convenience
  factories (FromJson, FromManifest, Empty)
- C# AzurePolicyCompiler static class for policy rule/definition compilation
- Compile functions take *const RegorusAliasRegistry (read-only via
  to_shared_ref for concurrent compilation safety)
- Fix pre-existing clippy warnings across multiple crates

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

bindings/csharp/Directory.Packages.props

@@ -1,7 +1,7 @@
 <Project>
   <PropertyGroup>
     <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
-    <RegorusPackageVersion>0.10.0</RegorusPackageVersion>
+    <RegorusPackageVersion>0.10.1</RegorusPackageVersion>
     <RegorusPackageVersionSuffix Condition="'$(VersionSuffix)' != ''">-$(VersionSuffix)</RegorusPackageVersionSuffix>
   </PropertyGroup>
 

bindings/csharp/README.md

@@ -150,3 +150,76 @@ const string ContextJson = """
 var allowed = RbacEngine.EvaluateCondition(Condition, ContextJson);
 Console.WriteLine($"RBAC condition allowed: {allowed}");
 ```
+
+## Azure Policy JSON Evaluation
+
+Compile and evaluate Azure Policy JSON `policyRule` definitions directly — no Rego translation required.
+The `AzurePolicyCompiler` compiles JSON policy rules into RVM programs that can be executed with the `Rvm` engine.
+
+```csharp
+using Regorus;
+
+// 1. Load alias definitions for the resource provider
+const string AliasesJson = """
+[{
+    "namespace": "Microsoft.Storage",
+    "resourceTypes": [{
+        "resourceType": "storageAccounts",
+        "aliases": [{
+            "name": "Microsoft.Storage/storageAccounts/supportsHttpsTrafficOnly",
+            "defaultPath": "properties.supportsHttpsTrafficOnly",
+            "paths": []
+        }]
+    }]
+}]
+""";
+
+using var registry = AliasRegistry.FromJson(AliasesJson);
+
+// 2. Compile a JSON policy rule (the native Azure Policy language)
+const string PolicyRule = """
+{
+    "if": {
+        "allOf": [
+            { "field": "type", "equals": "Microsoft.Storage/storageAccounts" },
+            { "field": "Microsoft.Storage/storageAccounts/supportsHttpsTrafficOnly", "equals": false }
+        ]
+    },
+    "then": { "effect": "deny" }
+}
+""";
+
+using var program = AzurePolicyCompiler.CompilePolicyRule(registry, PolicyRule);
+
+// 3. Normalize an ARM resource and evaluate
+var armResource = """
+{
+    "type": "Microsoft.Storage/storageAccounts",
+    "name": "mystorage",
+    "properties": { "supportsHttpsTrafficOnly": false }
+}
+""";
+var envelope = registry.NormalizeAndWrap(armResource);
+
+using var vm = new Rvm();
+vm.LoadProgram(program);
+vm.SetInputJson(envelope!);
+
+var result = vm.ExecuteEntryPoint("main");
+// result: {"effect": "deny"} for non-compliant, "<undefined>" for compliant
+Console.WriteLine($"Policy result: {result}");
+```
+
+**Context-dependent policies:** If your policy uses context functions like
+`subscription()`, `resourceGroup()`, or `requestContext()`, you must also set
+the VM context separately:
+
+```csharp
+// The context JSON from NormalizeAndWrap is in the input envelope,
+// but must also be provided to the VM's ambient context:
+vm.SetContextJson(contextJson);
+```
+
+You can also compile full policy definitions (with parameters) using
+`AzurePolicyCompiler.CompilePolicyDefinition()`. See
+`bindings/csharp/Regorus.Tests/AzurePolicyCompilerTests.cs` for comprehensive examples.

bindings/csharp/Regorus.Tests/AliasRegistryTests.cs

@@ -43,31 +43,28 @@ public class AliasRegistryTests
     [TestMethod]
     public void Create_and_dispose_succeeds()
     {
-        using var registry = new AliasRegistry();
+        using var registry = AliasRegistry.Empty();
         Assert.AreEqual(0, registry.Length);
     }
 
     [TestMethod]
     public void LoadJson_populates_registry()
     {
-        using var registry = new AliasRegistry();
-        registry.LoadJson(AliasesJson);
+        using var registry = AliasRegistry.FromJson(AliasesJson);
         Assert.AreEqual(1, registry.Length);
     }
 
     [TestMethod]
     public void LoadManifest_populates_registry()
     {
-        using var registry = new AliasRegistry();
-        registry.LoadManifest(ManifestJson);
+        using var registry = AliasRegistry.FromManifest(ManifestJson);
         Assert.AreEqual(1, registry.Length);
     }
 
     [TestMethod]
     public void NormalizeAndWrap_produces_envelope()
     {
-        using var registry = new AliasRegistry();
-        registry.LoadJson(AliasesJson);
+        using var registry = AliasRegistry.FromJson(AliasesJson);
 
         var resource = @"{
             ""name"": ""acct1"",
@@ -93,8 +90,7 @@ public class AliasRegistryTests
     [TestMethod]
     public void NormalizeAndWrap_with_context_and_parameters()
     {
-        using var registry = new AliasRegistry();
-        registry.LoadJson(AliasesJson);
+        using var registry = AliasRegistry.FromJson(AliasesJson);
 
         var resource = @"{
             ""name"": ""acct1"",
@@ -115,8 +111,7 @@ public class AliasRegistryTests
     [TestMethod]
     public void Denormalize_restores_properties()
     {
-        using var registry = new AliasRegistry();
-        registry.LoadJson(AliasesJson);
+        using var registry = AliasRegistry.FromJson(AliasesJson);
 
         var normalized = @"{
             ""name"": ""acct1"",
@@ -137,8 +132,7 @@ public class AliasRegistryTests
     [TestMethod]
     public void Round_trip_normalize_then_denormalize()
     {
-        using var registry = new AliasRegistry();
-        registry.LoadJson(AliasesJson);
+        using var registry = AliasRegistry.FromJson(AliasesJson);
 
         var resource = @"{
             ""name"": ""acct1"",
@@ -166,8 +160,7 @@ public class AliasRegistryTests
     [TestMethod]
     public void DataPlane_manifest_normalize()
     {
-        using var registry = new AliasRegistry();
-        registry.LoadManifest(ManifestJson);
+        using var registry = AliasRegistry.FromManifest(ManifestJson);
 
         var resource = @"{
             ""type"": ""Microsoft.KeyVault.Data/vaults/certificates"",
@@ -185,7 +178,7 @@ public class AliasRegistryTests
     [ExpectedException(typeof(InvalidOperationException))]
     public void LoadJson_invalid_throws()
     {
-        using var registry = new AliasRegistry();
-        registry.LoadJson("not valid json");
+        using var builder = new AliasRegistryBuilder();
+        builder.LoadJson("not valid json");
     }
 }

bindings/csharp/Regorus.Tests/AzurePolicyCompilerTests.cs

@@ -0,0 +1,436 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+using System;
+using System.Text.Json.Nodes;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Regorus;
+
+namespace Regorus.Tests;
+
+/// <summary>
+/// Tests for <see cref="AzurePolicyCompiler"/> — compiling Azure Policy JSON
+/// policyRule and policyDefinition into RVM programs and evaluating them.
+/// </summary>
+[TestClass]
+public class AzurePolicyCompilerTests
+{
+    // -----------------------------------------------------------------------
+    // Test data
+    // -----------------------------------------------------------------------
+
+    private const string StorageAliasesJson = @"[{
+        ""namespace"": ""Microsoft.Storage"",
+        ""resourceTypes"": [{
+            ""resourceType"": ""storageAccounts"",
+            ""capabilities"": ""SupportsTags, SupportsLocation"",
+            ""aliases"": [
+                {
+                    ""name"": ""Microsoft.Storage/storageAccounts/supportsHttpsTrafficOnly"",
+                    ""defaultPath"": ""properties.supportsHttpsTrafficOnly"",
+                    ""paths"": []
+                },
+                {
+                    ""name"": ""Microsoft.Storage/storageAccounts/minimumTlsVersion"",
+                    ""defaultPath"": ""properties.minimumTlsVersion"",
+                    ""paths"": []
+                }
+            ]
+        }]
+    }]";
+
+    /// <summary>Simple policy rule that checks the resource type.</summary>
+    private const string SimpleAuditRule = @"{
+        ""if"": {
+            ""field"": ""type"",
+            ""equals"": ""Microsoft.Storage/storageAccounts""
+        },
+        ""then"": { ""effect"": ""audit"" }
+    }";
+
+    /// <summary>Policy rule that uses an alias to check HTTPS-only.</summary>
+    private const string HttpsDenyRule = @"{
+        ""if"": {
+            ""allOf"": [
+                { ""field"": ""type"", ""equals"": ""Microsoft.Storage/storageAccounts"" },
+                { ""field"": ""Microsoft.Storage/storageAccounts/supportsHttpsTrafficOnly"", ""equals"": false }
+            ]
+        },
+        ""then"": { ""effect"": ""deny"" }
+    }";
+
+    /// <summary>Full policy definition with parameters.</summary>
+    private const string PolicyDefinitionWithParams = @"{
+        ""displayName"": ""Require HTTPS for storage accounts"",
+        ""policyType"": ""Custom"",
+        ""mode"": ""Indexed"",
+        ""parameters"": {
+            ""effect"": {
+                ""type"": ""String"",
+                ""defaultValue"": ""deny""
+            }
+        },
+        ""policyRule"": {
+            ""if"": {
+                ""allOf"": [
+                    { ""field"": ""type"", ""equals"": ""Microsoft.Storage/storageAccounts"" },
+                    { ""field"": ""Microsoft.Storage/storageAccounts/supportsHttpsTrafficOnly"", ""equals"": false }
+                ]
+            },
+            ""then"": { ""effect"": ""[parameters('effect')]"" }
+        }
+    }";
+
+    // -----------------------------------------------------------------------
+    // Helper
+    // -----------------------------------------------------------------------
+
+    /// <summary>
+    /// Wrap a normalized resource JSON and parameters into the input envelope
+    /// expected by compiled Azure Policy RVM programs.
+    /// </summary>
+    private static string WrapInput(string resourceJson, string parametersJson = "{}")
+    {
+        return $@"{{""resource"": {resourceJson}, ""parameters"": {parametersJson}}}";
+    }
+
+    /// <summary>
+    /// Compile a policy rule, load it into an RVM, set input, and execute.
+    /// Returns the result string from <c>ExecuteEntryPoint("main")</c>.
+    /// </summary>
+    private static string? CompileAndEval(
+        AliasRegistry? registry,
+        string policyRuleJson,
+        string inputJson)
+    {
+        using var program = AzurePolicyCompiler.CompilePolicyRule(registry, policyRuleJson);
+        using var vm = new Rvm();
+        vm.LoadProgram(program);
+        vm.SetInputJson(inputJson);
+        return vm.ExecuteEntryPoint("main");
+    }
+
+    // -----------------------------------------------------------------------
+    // CompilePolicyRule tests
+    // -----------------------------------------------------------------------
+
+    [TestMethod]
+    public void CompilePolicyRule_no_aliases_succeeds()
+    {
+        using var program = AzurePolicyCompiler.CompilePolicyRule(null, SimpleAuditRule);
+        Assert.IsNotNull(program);
+    }
+
+    [TestMethod]
+    public void CompilePolicyRule_with_aliases_succeeds()
+    {
+        using var registry = AliasRegistry.FromJson(StorageAliasesJson);
+
+        using var program = AzurePolicyCompiler.CompilePolicyRule(registry, HttpsDenyRule);
+        Assert.IsNotNull(program);
+    }
+
+    [TestMethod]
+    [ExpectedException(typeof(ArgumentNullException))]
+    public void CompilePolicyRule_null_json_throws()
+    {
+        AzurePolicyCompiler.CompilePolicyRule(null, null!);
+    }
+
+    [TestMethod]
+    [ExpectedException(typeof(InvalidOperationException))]
+    public void CompilePolicyRule_invalid_json_throws()
+    {
+        AzurePolicyCompiler.CompilePolicyRule(null, "not valid json");
+    }
+
+    // -----------------------------------------------------------------------
+    // CompilePolicyDefinition tests
+    // -----------------------------------------------------------------------
+
+    [TestMethod]
+    public void CompilePolicyDefinition_no_aliases_succeeds()
+    {
+        using var program = AzurePolicyCompiler.CompilePolicyDefinition(null, PolicyDefinitionWithParams);
+        Assert.IsNotNull(program);
+    }
+
+    [TestMethod]
+    public void CompilePolicyDefinition_with_aliases_succeeds()
+    {
+        using var registry = AliasRegistry.FromJson(StorageAliasesJson);
+
+        using var program = AzurePolicyCompiler.CompilePolicyDefinition(registry, PolicyDefinitionWithParams);
+        Assert.IsNotNull(program);
+    }
+
+    [TestMethod]
+    [ExpectedException(typeof(ArgumentNullException))]
+    public void CompilePolicyDefinition_null_json_throws()
+    {
+        AzurePolicyCompiler.CompilePolicyDefinition(null, null!);
+    }
+
+    [TestMethod]
+    [ExpectedException(typeof(InvalidOperationException))]
+    public void CompilePolicyDefinition_invalid_json_throws()
+    {
+        AzurePolicyCompiler.CompilePolicyDefinition(null, @"{""not"": ""a definition""}");
+    }
+
+    // -----------------------------------------------------------------------
+    // End-to-end evaluation tests
+    // -----------------------------------------------------------------------
+
+    [TestMethod]
+    public void Eval_simple_rule_matching_resource_returns_effect()
+    {
+        var input = WrapInput(
+            @"{""type"": ""microsoft.storage/storageaccounts""}");
+
+        var result = CompileAndEval(null, SimpleAuditRule, input);
+        Assert.IsNotNull(result, "expected a result for matching resource");
+
+        var doc = JsonNode.Parse(result!)!;
+        Assert.AreEqual("audit", doc["effect"]?.GetValue<string>(),
+            $"expected 'audit' effect, got: {result}");
+    }
+
+    [TestMethod]
+    public void Eval_simple_rule_non_matching_resource_returns_undefined()
+    {
+        var input = WrapInput(
+            @"{""type"": ""microsoft.compute/virtualmachines""}");
+
+        var result = CompileAndEval(null, SimpleAuditRule, input);
+        Assert.IsNotNull(result);
+        StringAssert.Contains(result!, "undefined",
+            "expected undefined for non-matching resource type");
+    }
+
+    [TestMethod]
+    public void Eval_alias_rule_non_compliant_returns_deny()
+    {
+        using var registry = AliasRegistry.FromJson(StorageAliasesJson);
+
+        // Non-compliant: HTTPS not enabled (normalized/lowercased form)
+        var input = WrapInput(
+            @"{""type"": ""microsoft.storage/storageaccounts"", ""supportshttpstrafficonly"": false}");
+
+        using var program = AzurePolicyCompiler.CompilePolicyRule(registry, HttpsDenyRule);
+        using var vm = new Rvm();
+        vm.LoadProgram(program);
+        vm.SetInputJson(input);
+
+        var result = vm.ExecuteEntryPoint("main");
+        Assert.IsNotNull(result);
+
+        var doc = JsonNode.Parse(result!)!;
+        Assert.AreEqual("deny", doc["effect"]?.GetValue<string>(),
+            $"expected 'deny' for non-compliant resource, got: {result}");
+    }
+
+    [TestMethod]
+    public void Eval_alias_rule_compliant_returns_undefined()
+    {
+        using var registry = AliasRegistry.FromJson(StorageAliasesJson);
+
+        // Compliant: HTTPS enabled
+        var input = WrapInput(
+            @"{""type"": ""microsoft.storage/storageaccounts"", ""supportshttpstrafficonly"": true}");
+
+        using var program = AzurePolicyCompiler.CompilePolicyRule(registry, HttpsDenyRule);
+        using var vm = new Rvm();
+        vm.LoadProgram(program);
+        vm.SetInputJson(input);
+
+        var result = vm.ExecuteEntryPoint("main");
+        Assert.IsNotNull(result);
+        StringAssert.Contains(result!, "undefined",
+            "expected undefined for compliant resource");
+    }
+
+    [TestMethod]
+    public void Eval_definition_with_default_parameters()
+    {
+        using var registry = AliasRegistry.FromJson(StorageAliasesJson);
+
+        using var program = AzurePolicyCompiler.CompilePolicyDefinition(
+            registry, PolicyDefinitionWithParams);
+        using var vm = new Rvm();
+        vm.LoadProgram(program);
+
+        // Non-compliant resource
+        var input = WrapInput(
+            @"{""type"": ""microsoft.storage/storageaccounts"", ""supportshttpstrafficonly"": false}");
+        vm.SetInputJson(input);
+
+        var result = vm.ExecuteEntryPoint("main");
+        Assert.IsNotNull(result);
+
+        var doc = JsonNode.Parse(result!)!;
+        // Default parameter value is "deny"
+        Assert.AreEqual("deny", doc["effect"]?.GetValue<string>(),
+            $"expected default 'deny' effect, got: {result}");
+    }
+
+    [TestMethod]
+    public void Eval_with_normalized_arm_resource_end_to_end()
+    {
+        using var registry = AliasRegistry.FromJson(StorageAliasesJson);
+
+        // Simulate the full production flow:
+        // 1. Start with an ARM resource
+        var armResource = @"{
+            ""type"": ""Microsoft.Storage/storageAccounts"",
+            ""name"": ""mystorage"",
+            ""location"": ""eastus"",
+            ""properties"": {
+                ""supportsHttpsTrafficOnly"": false,
+                ""minimumTlsVersion"": ""TLS1_0""
+            }
+        }";
+
+        // 2. Normalize via AliasRegistry
+        var normalizedEnvelope = registry.NormalizeAndWrap(
+            armResource,
+            apiVersion: null,
+            contextJson: "{}",
+            parametersJson: "{}");
+        Assert.IsNotNull(normalizedEnvelope);
+
+        // 3. Compile the policy rule
+        using var program = AzurePolicyCompiler.CompilePolicyRule(registry, HttpsDenyRule);
+
+        // 4. Execute
+        using var vm = new Rvm();
+        vm.LoadProgram(program);
+        vm.SetInputJson(normalizedEnvelope!);
+
+        var result = vm.ExecuteEntryPoint("main");
+        Assert.IsNotNull(result);
+
+        var doc = JsonNode.Parse(result!)!;
+        Assert.AreEqual("deny", doc["effect"]?.GetValue<string>(),
+            $"expected 'deny' for non-HTTPS storage account, got: {result}");
+    }
+
+    [TestMethod]
+    public void Eval_normalized_compliant_resource_end_to_end()
+    {
+        using var registry = AliasRegistry.FromJson(StorageAliasesJson);
+
+        var armResource = @"{
+            ""type"": ""Microsoft.Storage/storageAccounts"",
+            ""name"": ""secureastorage"",
+            ""location"": ""westus"",
+            ""properties"": {
+                ""supportsHttpsTrafficOnly"": true,
+                ""minimumTlsVersion"": ""TLS1_2""
+            }
+        }";
+
+        var normalizedEnvelope = registry.NormalizeAndWrap(
+            armResource,
+            apiVersion: null,
+            contextJson: "{}",
+            parametersJson: "{}");
+        Assert.IsNotNull(normalizedEnvelope);
+
+        using var program = AzurePolicyCompiler.CompilePolicyRule(registry, HttpsDenyRule);
+        using var vm = new Rvm();
+        vm.LoadProgram(program);
+        vm.SetInputJson(normalizedEnvelope!);
+
+        var result = vm.ExecuteEntryPoint("main");
+        Assert.IsNotNull(result);
+        StringAssert.Contains(result!, "undefined",
+            "expected undefined for compliant HTTPS storage account");
+    }
+
+    [TestMethod]
+    public void Program_can_be_serialized_and_reloaded()
+    {
+        using var program = AzurePolicyCompiler.CompilePolicyRule(null, SimpleAuditRule);
+
+        // Serialize to binary
+        var binary = program.SerializeBinary();
+        Assert.IsTrue(binary.Length > 0, "serialized program should not be empty");
+
+        // Deserialize and run
+        using var restored = Program.DeserializeBinary(binary, out var isPartial);
+        Assert.IsFalse(isPartial, "program should not be partial");
+
+        using var vm = new Rvm();
+        vm.LoadProgram(restored);
+        var input = WrapInput(@"{""type"": ""microsoft.storage/storageaccounts""}");
+        vm.SetInputJson(input);
+
+        var result = vm.ExecuteEntryPoint("main");
+        Assert.IsNotNull(result);
+        var doc = JsonNode.Parse(result!)!;
+        Assert.AreEqual("audit", doc["effect"]?.GetValue<string>());
+    }
+
+    [TestMethod]
+    public void Program_generates_listing()
+    {
+        using var program = AzurePolicyCompiler.CompilePolicyRule(null, SimpleAuditRule);
+        var listing = program.GenerateListing();
+        Assert.IsFalse(string.IsNullOrWhiteSpace(listing),
+            "generated listing should not be empty");
+    }
+
+    // -----------------------------------------------------------------------
+    // Context-dependent policy tests
+    // -----------------------------------------------------------------------
+
+    /// Policy rule that uses subscription() context function.
+    private const string ContextPolicyRule = @"{
+        ""if"": {
+            ""allOf"": [
+                { ""field"": ""type"", ""equals"": ""Microsoft.Storage/storageAccounts"" },
+                { ""value"": ""[subscription().subscriptionId]"", ""equals"": ""sub-123"" }
+            ]
+        },
+        ""then"": { ""effect"": ""deny"" }
+    }";
+
+    [TestMethod]
+    public void Eval_context_policy_with_set_context_returns_effect()
+    {
+        using var program = AzurePolicyCompiler.CompilePolicyRule(null, ContextPolicyRule);
+        using var vm = new Rvm();
+        vm.LoadProgram(program);
+
+        vm.SetContextJson(@"{""subscription"": {""subscriptionId"": ""sub-123""}}");
+
+        var input = WrapInput(
+            @"{""type"": ""microsoft.storage/storageaccounts""}");
+        vm.SetInputJson(input);
+
+        var result = vm.ExecuteEntryPoint("main");
+        Assert.IsNotNull(result);
+        var doc = JsonNode.Parse(result!)!;
+        Assert.AreEqual("deny", doc["effect"]?.GetValue<string>(),
+            $"expected 'deny' with matching context, got: {result}");
+    }
+
+    [TestMethod]
+    public void Eval_context_policy_without_context_returns_undefined()
+    {
+        using var program = AzurePolicyCompiler.CompilePolicyRule(null, ContextPolicyRule);
+        using var vm = new Rvm();
+        vm.LoadProgram(program);
+
+        // No context set — subscription() will be undefined
+        var input = WrapInput(
+            @"{""type"": ""microsoft.storage/storageaccounts""}");
+        vm.SetInputJson(input);
+
+        var result = vm.ExecuteEntryPoint("main");
+        Assert.IsNotNull(result);
+        StringAssert.Contains(result!, "undefined",
+            "expected undefined without context set");
+    }
+}

bindings/csharp/Regorus.Tests/AzurePolicyTests.cs

@@ -62,8 +62,7 @@ public class AzurePolicyTests
     [TestMethod]
     public void AliasRegistry_NormalizeAndWrap_produces_input_envelope()
     {
-        using var registry = new AliasRegistry();
-        registry.LoadJson(StorageAliasesJson);
+        using var registry = AliasRegistry.FromJson(StorageAliasesJson);
 
         var result = registry.NormalizeAndWrap(
             StorageResourceJson,
@@ -84,8 +83,7 @@ public class AzurePolicyTests
     [TestMethod]
     public void AliasRegistry_NormalizeAndWrap_flattens_properties()
     {
-        using var registry = new AliasRegistry();
-        registry.LoadJson(StorageAliasesJson);
+        using var registry = AliasRegistry.FromJson(StorageAliasesJson);
 
         var result = registry.NormalizeAndWrap(StorageResourceJson);
         Assert.IsNotNull(result);
@@ -107,8 +105,7 @@ public class AzurePolicyTests
     [TestMethod]
     public void AliasRegistry_NormalizeAndWrap_preserves_type_field()
     {
-        using var registry = new AliasRegistry();
-        registry.LoadJson(StorageAliasesJson);
+        using var registry = AliasRegistry.FromJson(StorageAliasesJson);
 
         var result = registry.NormalizeAndWrap(StorageResourceJson);
         var doc = JsonNode.Parse(result!);
@@ -125,8 +122,7 @@ public class AzurePolicyTests
     [TestMethod]
     public void AliasRegistry_NormalizeAndWrap_includes_parameters()
     {
-        using var registry = new AliasRegistry();
-        registry.LoadJson(StorageAliasesJson);
+        using var registry = AliasRegistry.FromJson(StorageAliasesJson);
 
         var parametersJson = @"{ ""effect"": ""Deny"" }";
         var result = registry.NormalizeAndWrap(
@@ -143,8 +139,7 @@ public class AzurePolicyTests
     [TestMethod]
     public void AliasRegistry_Denormalize_roundtrips_correctly()
     {
-        using var registry = new AliasRegistry();
-        registry.LoadJson(StorageAliasesJson);
+        using var registry = AliasRegistry.FromJson(StorageAliasesJson);
 
         // Normalize the ARM resource.
         var envelope = registry.NormalizeAndWrap(StorageResourceJson);
@@ -177,8 +172,7 @@ public class AzurePolicyTests
         }
 
         var aliasesJson = File.ReadAllText(aliasesPath);
-        using var registry = new AliasRegistry();
-        registry.LoadJson(aliasesJson);
+        using var registry = AliasRegistry.FromJson(aliasesJson);
 
         // The test_aliases.json file contains multiple providers.
         Assert.IsTrue(registry.Length > 0,

bindings/csharp/Regorus/AliasRegistry.cs

@@ -8,51 +8,43 @@ using Regorus.Internal;
 namespace Regorus
 {
     /// <summary>
-    /// Manages Azure Policy alias definitions used for resource normalization
+    /// Immutable Azure Policy alias registry used for resource normalization
     /// and policy compilation.
     /// </summary>
     public unsafe sealed class AliasRegistry : SafeHandleWrapper
     {
-        /// <summary>
-        /// Create an empty alias registry.
-        /// </summary>
-        public AliasRegistry()
-            : base(RegorusAliasRegistryHandle.Create(), nameof(AliasRegistry))
+        internal AliasRegistry(RegorusAliasRegistryHandle handle)
+            : base(handle, nameof(AliasRegistry))
         {
         }
 
         /// <summary>
-        /// Load control-plane alias data (array of ProviderAliases) from a JSON string.
+        /// Create an empty immutable alias registry.
         /// </summary>
-        /// <param name="json">JSON array of ProviderAliases (e.g. from Get-AzPolicyAlias or ResourceTypesAndAliases.json)</param>
-        public void LoadJson(string json)
+        public static AliasRegistry Empty()
         {
-            Utf8Marshaller.WithUtf8(json, jsonPtr =>
-            {
-                UseHandle(regPtr =>
-                {
-                    CheckAndDropResult(API.regorus_alias_registry_load_json(
-                        (RegorusAliasRegistry*)regPtr, (byte*)jsonPtr));
-                    return 0;
-                });
-            });
+            using var builder = new AliasRegistryBuilder();
+            return builder.Build();
         }
 
         /// <summary>
-        /// Load a data-plane policy manifest from a JSON string.
+        /// Create an immutable alias registry from control-plane alias JSON.
         /// </summary>
-        /// <param name="json">JSON object containing a DataPolicyManifest</param>
-        public void LoadManifest(string json)
+        public static AliasRegistry FromJson(string json)
         {
-            Utf8Marshaller.WithUtf8(json, jsonPtr =>
-            {
-                UseHandle(regPtr =>
-                {
-                    CheckAndDropResult(API.regorus_alias_registry_load_manifest(
-                        (RegorusAliasRegistry*)regPtr, (byte*)jsonPtr));
-                    return 0;
-                });
-            });
+            using var builder = new AliasRegistryBuilder();
+            builder.LoadJson(json);
+            return builder.Build();
+        }
+
+        /// <summary>
+        /// Create an immutable alias registry from a data-plane manifest JSON document.
+        /// </summary>
+        public static AliasRegistry FromManifest(string json)
+        {
+            using var builder = new AliasRegistryBuilder();
+            builder.LoadManifest(json);
+            return builder.Build();
         }
 
         /// <summary>
@@ -74,11 +66,6 @@ namespace Regorus
         /// Normalize an ARM resource JSON and wrap it into the standard input envelope
         /// expected by a compiled Azure Policy program.
         /// </summary>
-        /// <param name="resourceJson">Raw ARM resource JSON</param>
-        /// <param name="apiVersion">API version string (e.g. "2023-01-01"), or null to use default alias paths</param>
-        /// <param name="contextJson">Additional context JSON object (pass "{}" if none)</param>
-        /// <param name="parametersJson">Policy parameter values JSON (pass "{}" if none)</param>
-        /// <returns>JSON string: { "resource": &lt;normalized&gt;, "context": &lt;context&gt;, "parameters": &lt;params&gt; }</returns>
         public string? NormalizeAndWrap(string resourceJson, string? apiVersion = null, string contextJson = "{}", string parametersJson = "{}")
         {
             return Utf8Marshaller.WithUtf8(resourceJson, resPtr =>
@@ -96,27 +83,22 @@ namespace Regorus
                                         (byte*)ctxPtr, (byte*)paramsPtr));
                             });
                         }
-                        else
-                        {
-                            return Utf8Marshaller.WithUtf8(apiVersion, apiPtr =>
-                                UseHandle(regPtr =>
-                                {
-                                    return ResultHelpers.GetStringResult(
-                                        API.regorus_alias_registry_normalize_and_wrap(
-                                            (RegorusAliasRegistry*)regPtr,
-                                            (byte*)resPtr, (byte*)apiPtr,
-                                            (byte*)ctxPtr, (byte*)paramsPtr));
-                                }));
-                        }
+
+                        return Utf8Marshaller.WithUtf8(apiVersion, apiPtr =>
+                            UseHandle(regPtr =>
+                            {
+                                return ResultHelpers.GetStringResult(
+                                    API.regorus_alias_registry_normalize_and_wrap(
+                                        (RegorusAliasRegistry*)regPtr,
+                                        (byte*)resPtr, (byte*)apiPtr,
+                                        (byte*)ctxPtr, (byte*)paramsPtr));
+                            }));
                     })));
         }
 
         /// <summary>
         /// Denormalize a previously-normalized resource JSON back to ARM format.
         /// </summary>
-        /// <param name="normalizedJson">The normalized resource JSON</param>
-        /// <param name="apiVersion">API version string, or null to use default alias paths</param>
-        /// <returns>Denormalized ARM JSON string</returns>
         public string? Denormalize(string normalizedJson, string? apiVersion = null)
         {
             return Utf8Marshaller.WithUtf8(normalizedJson, normPtr =>
@@ -131,23 +113,16 @@ namespace Regorus
                                 (byte*)normPtr, null));
                     });
                 }
-                else
-                {
-                    return Utf8Marshaller.WithUtf8(apiVersion, apiPtr =>
-                        UseHandle(regPtr =>
-                        {
-                            return ResultHelpers.GetStringResult(
-                                API.regorus_alias_registry_denormalize(
-                                    (RegorusAliasRegistry*)regPtr,
-                                    (byte*)normPtr, (byte*)apiPtr));
-                        }));
-                }
-            });
-        }
 
-        private static string? CheckAndDropResult(RegorusResult result)
-        {
-            return ResultHelpers.GetStringResult(result);
+                return Utf8Marshaller.WithUtf8(apiVersion, apiPtr =>
+                    UseHandle(regPtr =>
+                    {
+                        return ResultHelpers.GetStringResult(
+                            API.regorus_alias_registry_denormalize(
+                                (RegorusAliasRegistry*)regPtr,
+                                (byte*)normPtr, (byte*)apiPtr));
+                    }));
+            });
         }
     }
 }

bindings/csharp/Regorus/AliasRegistryBuilder.cs

@@ -0,0 +1,69 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+using System;
+using Regorus.Internal;
+
+#nullable enable
+namespace Regorus
+{
+    /// <summary>
+    /// Mutable, single-threaded builder for <see cref="AliasRegistry"/>.
+    /// Load alias data, then call <see cref="Build"/> to freeze the registry.
+    /// </summary>
+    public unsafe sealed class AliasRegistryBuilder : SafeHandleWrapper
+    {
+        /// <summary>
+        /// Create an empty alias registry builder.
+        /// </summary>
+        public AliasRegistryBuilder()
+            : base(RegorusAliasRegistryBuilderHandle.Create(), nameof(AliasRegistryBuilder))
+        {
+        }
+
+        /// <summary>
+        /// Load control-plane alias data (array of ProviderAliases) from a JSON string.
+        /// </summary>
+        public void LoadJson(string json)
+        {
+            Utf8Marshaller.WithUtf8(json, jsonPtr =>
+            {
+                UseHandle(builderPtr =>
+                {
+                    ResultHelpers.GetStringResult(API.regorus_alias_registry_builder_load_json(
+                        (RegorusAliasRegistryBuilder*)builderPtr,
+                        (byte*)jsonPtr));
+                });
+            });
+        }
+
+        /// <summary>
+        /// Load a data-plane policy manifest from a JSON string.
+        /// </summary>
+        public void LoadManifest(string json)
+        {
+            Utf8Marshaller.WithUtf8(json, jsonPtr =>
+            {
+                UseHandle(builderPtr =>
+                {
+                    ResultHelpers.GetStringResult(API.regorus_alias_registry_builder_load_manifest(
+                        (RegorusAliasRegistryBuilder*)builderPtr,
+                        (byte*)jsonPtr));
+                });
+            });
+        }
+
+        /// <summary>
+        /// Freeze the builder into an immutable, thread-safe alias registry.
+        /// </summary>
+        public AliasRegistry Build()
+        {
+            return UseHandle(builderPtr =>
+            {
+                var registryPtr = ResultHelpers.GetPointerResult(
+                    API.regorus_alias_registry_builder_build((RegorusAliasRegistryBuilder*)builderPtr));
+                return new AliasRegistry(RegorusAliasRegistryHandle.FromPointer(registryPtr));
+            });
+        }
+    }
+}

bindings/csharp/Regorus/AzurePolicyCompiler.cs

@@ -0,0 +1,183 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+using System;
+using Regorus.Internal;
+
+#nullable enable
+namespace Regorus
+{
+    /// <summary>
+    /// Provides static methods for compiling Azure Policy JSON definitions
+    /// into RVM programs that can be executed by <see cref="Rvm"/>.
+    /// </summary>
+    /// <remarks>
+    /// <para>
+    /// This class bridges the gap between Azure Policy JSON (the native
+    /// Azure policy language with <c>policyRule</c>, <c>field</c>,
+    /// <c>equals</c>, etc.) and Regorus's RVM execution engine.
+    /// </para>
+    ///
+    /// <para>
+    /// <b>Typical workflow:</b>
+    /// </para>
+    /// <list type="number">
+    /// <item>Load alias definitions with <see cref="AliasRegistryBuilder"/> and freeze them into an <see cref="AliasRegistry"/>.</item>
+    /// <item>Normalize the ARM resource via <see cref="AliasRegistry.NormalizeAndWrap"/>.</item>
+    /// <item>Compile the JSON policyRule with <see cref="CompilePolicyRule"/> or the
+    ///        full definition with <see cref="CompilePolicyDefinition"/>.</item>
+    /// <item>Execute the resulting <see cref="Program"/> in an <see cref="Rvm"/>
+    ///        instance with the normalized input.</item>
+    /// </list>
+    ///
+    /// <para>
+    /// <b>Context-dependent policies:</b> Policies that use context functions
+    /// such as <c>subscription()</c>, <c>resourceGroup()</c>, or
+    /// <c>requestContext()</c> require the VM context to be set separately via
+    /// <see cref="Rvm.SetContextJson"/> before execution. The context JSON
+    /// returned by <see cref="AliasRegistry.NormalizeAndWrap"/> is passed as
+    /// <c>input.context</c> but is <b>not</b> automatically wired into the VM's
+    /// ambient context — the caller must do both:
+    /// <c>vm.SetInputJson(envelope)</c> and <c>vm.SetContextJson(contextJson)</c>.
+    /// </para>
+    /// </remarks>
+    public static unsafe class AzurePolicyCompiler
+    {
+        /// <summary>
+        /// Compile an Azure Policy JSON policy rule into an RVM <see cref="Program"/>.
+        /// </summary>
+        /// <param name="aliasRegistry">
+        /// Alias registry for resolving fully-qualified alias names in field
+        /// references.  Pass <c>null</c> if no alias resolution is needed.
+        /// <para>
+        /// <b>Warning:</b> When <c>null</c>, alias field references compile as raw
+        /// property paths and will silently produce incorrect evaluation results for
+        /// policies that use aliases.  Modify/Append effect policies will also skip
+        /// the compile-time modifiability validation.  Only pass <c>null</c> when the
+        /// policy is known to contain no alias references (e.g. simple type/location
+        /// checks or unit-test scenarios).
+        /// </para>
+        /// </param>
+        /// <param name="policyRuleJson">
+        /// JSON string containing the policyRule object, e.g.
+        /// <c>{ "if": { "field": "type", "equals": "..." }, "then": { "effect": "deny" } }</c>
+        /// </param>
+        /// <returns>
+        /// A compiled <see cref="Program"/> ready to be loaded into an
+        /// <see cref="Rvm"/> instance.
+        /// </returns>
+        /// <exception cref="ArgumentNullException">
+        /// Thrown when <paramref name="policyRuleJson"/> is <c>null</c>.
+        /// </exception>
+        /// <exception cref="Exception">
+        /// Thrown when parsing or compilation fails.
+        /// </exception>
+        public static Program CompilePolicyRule(AliasRegistry? aliasRegistry, string policyRuleJson)
+        {
+            if (policyRuleJson is null)
+            {
+                throw new ArgumentNullException(nameof(policyRuleJson));
+            }
+
+            return Utf8Marshaller.WithUtf8(policyRuleJson, rulePtr =>
+            {
+                if (aliasRegistry is null)
+                {
+                    var result = API.regorus_compile_azure_policy_rule(
+                        null, (byte*)rulePtr);
+                    return GetProgramResult(result);
+                }
+                else
+                {
+                    return aliasRegistry.UseHandleForInterop(regPtr =>
+                    {
+                        var result = API.regorus_compile_azure_policy_rule(
+                            (RegorusAliasRegistry*)regPtr, (byte*)rulePtr);
+                        return GetProgramResult(result);
+                    });
+                }
+            });
+        }
+
+        /// <summary>
+        /// Compile a full Azure Policy definition JSON into an RVM <see cref="Program"/>.
+        /// </summary>
+        /// <param name="aliasRegistry">
+        /// Alias registry for resolving fully-qualified alias names in field
+        /// references.  Pass <c>null</c> if no alias resolution is needed.
+        /// <para>
+        /// <b>Warning:</b> When <c>null</c>, alias field references compile as raw
+        /// property paths and will silently produce incorrect evaluation results for
+        /// policies that use aliases.  Modify/Append effect policies will also skip
+        /// the compile-time modifiability validation.  Only pass <c>null</c> when the
+        /// policy is known to contain no alias references (e.g. simple type/location
+        /// checks or unit-test scenarios).
+        /// </para>
+        /// </param>
+        /// <param name="policyDefinitionJson">
+        /// JSON string containing the full policy definition, which includes
+        /// <c>policyRule</c>, <c>parameters</c>, <c>displayName</c>, etc.
+        /// Accepted in both wrapped and unwrapped forms.
+        /// </param>
+        /// <returns>
+        /// A compiled <see cref="Program"/> ready to be loaded into an
+        /// <see cref="Rvm"/> instance.
+        /// </returns>
+        /// <exception cref="ArgumentNullException">
+        /// Thrown when <paramref name="policyDefinitionJson"/> is <c>null</c>.
+        /// </exception>
+        /// <exception cref="Exception">
+        /// Thrown when parsing or compilation fails.
+        /// </exception>
+        public static Program CompilePolicyDefinition(AliasRegistry? aliasRegistry, string policyDefinitionJson)
+        {
+            if (policyDefinitionJson is null)
+            {
+                throw new ArgumentNullException(nameof(policyDefinitionJson));
+            }
+
+            return Utf8Marshaller.WithUtf8(policyDefinitionJson, defnPtr =>
+            {
+                if (aliasRegistry is null)
+                {
+                    var result = API.regorus_compile_azure_policy_definition(
+                        null, (byte*)defnPtr);
+                    return GetProgramResult(result);
+                }
+                else
+                {
+                    return aliasRegistry.UseHandleForInterop(regPtr =>
+                    {
+                        var result = API.regorus_compile_azure_policy_definition(
+                            (RegorusAliasRegistry*)regPtr, (byte*)defnPtr);
+                        return GetProgramResult(result);
+                    });
+                }
+            });
+        }
+
+        private static Program GetProgramResult(RegorusResult result)
+        {
+            try
+            {
+                if (result.status != RegorusStatus.Ok)
+                {
+                    var message = Utf8Marshaller.FromUtf8(result.error_message);
+                    throw result.status.CreateException(message);
+                }
+
+                if (result.data_type != RegorusDataType.Pointer || result.pointer_value == null)
+                {
+                    throw new Exception("Expected program pointer but got different data type");
+                }
+
+                var handle = RegorusProgramHandle.FromPointer((IntPtr)result.pointer_value);
+                return new Program(handle);
+            }
+            finally
+            {
+                API.regorus_result_drop(result);
+            }
+        }
+    }
+}

bindings/csharp/Regorus/NativeMethods.cs

@@ -178,6 +178,14 @@ namespace Regorus.Internal
         [DllImport(LibraryName, EntryPoint = "regorus_rvm_set_input", CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
         internal static extern RegorusResult regorus_rvm_set_input(RegorusRvm* vm, byte* input_json);
 
+        /// <summary>
+        /// Set the context document for the RVM.
+        /// The context provides host-supplied ambient data (e.g. resourceGroup(), subscription())
+        /// that Azure Policy functions can access.
+        /// </summary>
+        [DllImport(LibraryName, EntryPoint = "regorus_rvm_set_context", CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        internal static extern RegorusResult regorus_rvm_set_context(RegorusRvm* vm, byte* context_json);
+
         /// <summary>
         /// Execute the program.
         /// </summary>
@@ -490,6 +498,20 @@ namespace Regorus.Internal
         [DllImport(LibraryName, EntryPoint = "regorus_compile_policy_for_target", CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
         internal static extern RegorusResult regorus_compile_policy_for_target(byte* data_json, RegorusPolicyModule* modules, UIntPtr modules_len);
 
+        /// <summary>
+        /// Compile an Azure Policy JSON policy rule into an RVM program.
+        /// </summary>
+        [DllImport(LibraryName, EntryPoint = "regorus_compile_azure_policy_rule", CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        internal static extern RegorusResult regorus_compile_azure_policy_rule(
+            RegorusAliasRegistry* registry, byte* policy_rule_json);
+
+        /// <summary>
+        /// Compile a full Azure Policy definition JSON into an RVM program.
+        /// </summary>
+        [DllImport(LibraryName, EntryPoint = "regorus_compile_azure_policy_definition", CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        internal static extern RegorusResult regorus_compile_azure_policy_definition(
+            RegorusAliasRegistry* registry, byte* policy_definition_json);
+
         #endregion
 
         #region Compiled Policy Methods
@@ -673,10 +695,34 @@ namespace Regorus.Internal
         #region Alias Registry Methods
 
         /// <summary>
-        /// Create a new, empty AliasRegistry.
+        /// Create a new alias registry builder.
         /// </summary>
-        [DllImport(LibraryName, EntryPoint = "regorus_alias_registry_new", CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
-        internal static extern RegorusAliasRegistry* regorus_alias_registry_new();
+        [DllImport(LibraryName, EntryPoint = "regorus_alias_registry_builder_new", CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        internal static extern RegorusAliasRegistryBuilder* regorus_alias_registry_builder_new();
+
+        /// <summary>
+        /// Drop an alias registry builder.
+        /// </summary>
+        [DllImport(LibraryName, EntryPoint = "regorus_alias_registry_builder_drop", CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        internal static extern void regorus_alias_registry_builder_drop(RegorusAliasRegistryBuilder* builder);
+
+        /// <summary>
+        /// Load control-plane alias data into the builder.
+        /// </summary>
+        [DllImport(LibraryName, EntryPoint = "regorus_alias_registry_builder_load_json", CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        internal static extern RegorusResult regorus_alias_registry_builder_load_json(RegorusAliasRegistryBuilder* builder, byte* json);
+
+        /// <summary>
+        /// Load a data-plane policy manifest into the builder.
+        /// </summary>
+        [DllImport(LibraryName, EntryPoint = "regorus_alias_registry_builder_load_manifest", CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        internal static extern RegorusResult regorus_alias_registry_builder_load_manifest(RegorusAliasRegistryBuilder* builder, byte* json);
+
+        /// <summary>
+        /// Freeze a builder into an immutable alias registry.
+        /// </summary>
+        [DllImport(LibraryName, EntryPoint = "regorus_alias_registry_builder_build", CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        internal static extern RegorusResult regorus_alias_registry_builder_build(RegorusAliasRegistryBuilder* builder);
 
         /// <summary>
         /// Drop an AliasRegistry.
@@ -684,18 +730,6 @@ namespace Regorus.Internal
         [DllImport(LibraryName, EntryPoint = "regorus_alias_registry_drop", CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
         internal static extern void regorus_alias_registry_drop(RegorusAliasRegistry* registry);
 
-        /// <summary>
-        /// Load control-plane alias data (array of ProviderAliases) into the registry.
-        /// </summary>
-        [DllImport(LibraryName, EntryPoint = "regorus_alias_registry_load_json", CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
-        internal static extern RegorusResult regorus_alias_registry_load_json(RegorusAliasRegistry* registry, byte* json);
-
-        /// <summary>
-        /// Load a data-plane policy manifest into the registry.
-        /// </summary>
-        [DllImport(LibraryName, EntryPoint = "regorus_alias_registry_load_manifest", CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
-        internal static extern RegorusResult regorus_alias_registry_load_manifest(RegorusAliasRegistry* registry, byte* json);
-
         /// <summary>
         /// Return the number of resource types loaded in the alias registry.
         /// </summary>
@@ -923,6 +957,14 @@ namespace Regorus.Internal
         public byte* content;
     }
 
+    /// <summary>
+    /// Wrapper for AliasRegistryBuilder.
+    /// </summary>
+    [StructLayout(LayoutKind.Sequential)]
+    internal unsafe partial struct RegorusAliasRegistryBuilder
+    {
+    }
+
     /// <summary>
     /// Wrapper for AliasRegistry.
     /// </summary>

bindings/csharp/Regorus/Program.cs

@@ -15,7 +15,7 @@ namespace Regorus
     /// </summary>
     public unsafe sealed class Program : SafeHandleWrapper
     {
-        private Program(RegorusProgramHandle handle)
+        internal Program(RegorusProgramHandle handle)
             : base(handle, nameof(Program))
         {
         }

bindings/csharp/Regorus/ResultHelpers.cs

@@ -69,5 +69,29 @@ namespace Regorus.Internal
                 API.regorus_result_drop(result);
             }
         }
+
+
+        internal static IntPtr GetPointerResult(RegorusResult result)
+        {
+            try
+            {
+                if (result.status != RegorusStatus.Ok)
+                {
+                    var message = Utf8Marshaller.FromUtf8(result.error_message);
+                    throw result.status.CreateException(message);
+                }
+
+                if (result.data_type != RegorusDataType.Pointer || result.pointer_value == null)
+                {
+                    throw new InvalidOperationException("Expected pointer result.");
+                }
+
+                return (IntPtr)result.pointer_value;
+            }
+            finally
+            {
+                API.regorus_result_drop(result);
+            }
+        }
     }
 }

bindings/csharp/Regorus/Rvm.cs

@@ -106,6 +106,24 @@ namespace Regorus
             });
         }
 
+        /// <summary>
+        /// Set the context document for the VM.
+        /// The context provides host-supplied ambient data (e.g. resourceGroup(),
+        /// subscription()) that Azure Policy functions can access via LoadContext
+        /// instructions.
+        /// </summary>
+        public void SetContextJson(string contextJson)
+        {
+            Utf8Marshaller.WithUtf8(contextJson, contextPtr =>
+            {
+                UseHandle(vmPtr =>
+                {
+                    CheckAndDropResult(API.regorus_rvm_set_context((RegorusRvm*)vmPtr, (byte*)contextPtr));
+                    return 0;
+                });
+            });
+        }
+
         /// <summary>
         /// Set the execution mode (0 = run-to-completion, 1 = suspendable).
         /// </summary>

bindings/csharp/Regorus/SafeHandles.cs

@@ -184,28 +184,48 @@ namespace Regorus
         }
     }
 
+    internal sealed class RegorusAliasRegistryBuilderHandle : SafeHandleZeroOrMinusOneIsInvalid
+    {
+        private RegorusAliasRegistryBuilderHandle() : base(ownsHandle: true)
+        {
+        }
+
+        internal static RegorusAliasRegistryBuilderHandle Create()
+        {
+            unsafe
+            {
+                var raw = Internal.API.regorus_alias_registry_builder_new();
+                if (raw is null)
+                {
+                    throw new InvalidOperationException("Failed to create Regorus alias registry builder.");
+                }
+
+                var handle = new RegorusAliasRegistryBuilderHandle();
+                handle.SetHandle((IntPtr)raw);
+                return handle;
+            }
+        }
+
+        protected override bool ReleaseHandle()
+        {
+            if (!IsInvalid)
+            {
+                unsafe
+                {
+                    Internal.API.regorus_alias_registry_builder_drop((Internal.RegorusAliasRegistryBuilder*)handle);
+                }
+                SetHandle(IntPtr.Zero);
+            }
+            return true;
+        }
+    }
+
     internal sealed class RegorusAliasRegistryHandle : SafeHandleZeroOrMinusOneIsInvalid
     {
         private RegorusAliasRegistryHandle() : base(ownsHandle: true)
         {
         }
 
-        internal static RegorusAliasRegistryHandle Create()
-        {
-            unsafe
-            {
-                var raw = Internal.API.regorus_alias_registry_new();
-                if (raw is null)
-                {
-                    throw new InvalidOperationException("Failed to create Regorus alias registry.");
-                }
-
-                var handle = new RegorusAliasRegistryHandle();
-                handle.SetHandle((IntPtr)raw);
-                return handle;
-            }
-        }
-
         internal static RegorusAliasRegistryHandle FromPointer(IntPtr pointer)
         {
             if (pointer == IntPtr.Zero)

bindings/csharp/TargetExampleApp/Program.cs

@@ -232,6 +232,9 @@ allow if {
 
         Console.WriteLine("\n8. RVM host await (suspend/resume):");
         DemonstrateRvmHostAwait();
+
+        Console.WriteLine("\n9. Azure Policy JSON compilation:");
+        DemonstrateAzurePolicyJsonCompilation();
     }
 
     static void DemonstrateConcurrentEvaluation(Regorus.CompiledPolicy compiledPolicy)
@@ -492,4 +495,80 @@ allow if {
         var resumed = vm.Resume("{\"tier\":\"gold\"}");
         Console.WriteLine($"HostAwait resumed result: {resumed}");
     }
+
+    // Azure Policy JSON constants
+    private const string STORAGE_ALIASES_JSON = @"[{
+        ""namespace"": ""Microsoft.Storage"",
+        ""resourceTypes"": [{
+            ""resourceType"": ""storageAccounts"",
+            ""capabilities"": ""SupportsTags, SupportsLocation"",
+            ""aliases"": [
+                {
+                    ""name"": ""Microsoft.Storage/storageAccounts/supportsHttpsTrafficOnly"",
+                    ""defaultPath"": ""properties.supportsHttpsTrafficOnly"",
+                    ""paths"": []
+                }
+            ]
+        }]
+    }]";
+
+    private const string HTTPS_DENY_RULE = @"{
+        ""if"": {
+            ""allOf"": [
+                { ""field"": ""type"", ""equals"": ""Microsoft.Storage/storageAccounts"" },
+                { ""field"": ""Microsoft.Storage/storageAccounts/supportsHttpsTrafficOnly"", ""equals"": false }
+            ]
+        },
+        ""then"": { ""effect"": ""deny"" }
+    }";
+
+    static void DemonstrateAzurePolicyJsonCompilation()
+    {
+        // 1. Set up alias registry
+        using var registry = Regorus.AliasRegistry.FromJson(STORAGE_ALIASES_JSON);
+        Console.WriteLine("Loaded storage account aliases");
+
+        // 2. Compile the JSON policy rule directly (no Rego needed)
+        using var program = Regorus.AzurePolicyCompiler.CompilePolicyRule(registry, HTTPS_DENY_RULE);
+        Console.WriteLine("Compiled Azure Policy JSON rule to RVM program");
+
+        // 3. Normalize an ARM resource
+        var armResource = @"{
+            ""type"": ""Microsoft.Storage/storageAccounts"",
+            ""name"": ""insecurestorage"",
+            ""location"": ""eastus"",
+            ""properties"": { ""supportsHttpsTrafficOnly"": false }
+        }";
+        var envelope = registry.NormalizeAndWrap(armResource, apiVersion: null, contextJson: "{}", parametersJson: "{}");
+        Console.WriteLine($"Normalized ARM resource to evaluation envelope");
+
+        // 4. Execute in the RVM
+        //    Note: For policies using context functions (subscription(), resourceGroup()),
+        //    call vm.SetContextJson(contextJson) before execution. The context from
+        //    NormalizeAndWrap is in the envelope but must also be set on the VM separately.
+        using var vm = new Regorus.Rvm();
+        vm.LoadProgram(program);
+        vm.SetInputJson(envelope!);
+        // vm.SetContextJson(contextJson); // ← required for context-dependent policies
+        var result = vm.ExecuteEntryPoint("main");
+        Console.WriteLine($"Evaluation result (non-compliant): {result}");
+
+        // 5. Test with a compliant resource
+        var compliantResource = @"{
+            ""type"": ""Microsoft.Storage/storageAccounts"",
+            ""name"": ""securestorage"",
+            ""location"": ""eastus"",
+            ""properties"": { ""supportsHttpsTrafficOnly"": true }
+        }";
+        var compliantEnvelope = registry.NormalizeAndWrap(compliantResource, apiVersion: null, contextJson: "{}", parametersJson: "{}");
+        using var vm2 = new Regorus.Rvm();
+        vm2.LoadProgram(program);
+        vm2.SetInputJson(compliantEnvelope!);
+        var compliantResult = vm2.ExecuteEntryPoint("main");
+        Console.WriteLine($"Evaluation result (compliant): {compliantResult}");
+
+        // 6. Demonstrate program serialization
+        var binary = program.SerializeBinary();
+        Console.WriteLine($"Serialized program size: {binary.Length} bytes");
+    }
 }

bindings/ffi/Cargo.lock

@@ -1163,7 +1163,7 @@ dependencies = [
 
 [[package]]
 name = "regorus-ffi"
-version = "0.10.0"
+version = "0.10.1"
 dependencies = [
  "anyhow",
  "cbindgen",
@@ -1837,9 +1837,9 @@ dependencies = [
 
 [[package]]
 name = "zerofrom"
-version = "0.1.8"
+version = "0.1.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0ec05a11813ea801ff6d75110ad09cd0824ddba17dfe17128ea0d5f68e6c5272"
+checksum = "69faa1f2a1ea75661980b013019ed6687ed0e83d069bc1114e2cc74c6c04c4df"
 dependencies = [
  "zerofrom-derive",
 ]

bindings/ffi/Cargo.toml

@@ -2,7 +2,7 @@
 
 [package]
 name = "regorus-ffi"
-version = "0.10.0"
+version = "0.10.1"
 edition = "2021"
 license = "MIT AND Apache-2.0 AND BSD-3-Clause"
 

bindings/ffi/src/alias_registry.rs

@@ -5,66 +5,108 @@
 
 #![cfg(feature = "azure_policy")]
 
-use crate::common::{from_c_str, to_ref, RegorusResult, RegorusStatus};
+use crate::common::{from_c_str, to_ref, to_shared_ref, RegorusResult, RegorusStatus};
 use crate::panic_guard::with_unwind_guard;
 
 use alloc::boxed::Box;
 use alloc::format;
 use alloc::string::String;
-use anyhow::Result;
-use core::ffi::c_char;
-use core::ptr;
+use alloc::sync::Arc;
+use anyhow::{anyhow, Result};
+use core::ffi::{c_char, c_void};
+use core::{mem, ptr};
 
 use regorus::languages::azure_policy::aliases::AliasRegistry;
 
-/// Opaque wrapper for `AliasRegistry`.
-pub struct RegorusAliasRegistry {
-    registry: AliasRegistry,
-}
-
-// ---------------------------------------------------------------------------
-// Lifecycle
-// ---------------------------------------------------------------------------
-
-/// Create a new, empty `AliasRegistry`.
+/// Mutable builder for `AliasRegistry`.
 ///
-/// The caller must eventually call `regorus_alias_registry_drop` to free the handle.
-#[no_mangle]
-pub extern "C" fn regorus_alias_registry_new() -> *mut RegorusAliasRegistry {
-    let wrapper = RegorusAliasRegistry {
-        registry: AliasRegistry::new(),
-    };
-    Box::into_raw(Box::new(wrapper))
+/// This handle is intentionally single-threaded and must not be used
+/// concurrently. Callers should finish loading alias data and then freeze it
+/// into a `RegorusAliasRegistry` via `regorus_alias_registry_builder_build`.
+pub struct RegorusAliasRegistryBuilder {
+    registry: AliasRegistry,
+    built: bool,
 }
 
-/// Drop a `RegorusAliasRegistry`.
+impl RegorusAliasRegistryBuilder {
+    fn new() -> Self {
+        Self {
+            registry: AliasRegistry::new(),
+            built: false,
+        }
+    }
+
+    fn registry_mut(&mut self) -> Result<&mut AliasRegistry> {
+        if self.built {
+            return Err(anyhow!("alias registry builder has already been built"));
+        }
+        Ok(&mut self.registry)
+    }
+
+    fn build(&mut self) -> Result<RegorusAliasRegistry> {
+        if self.built {
+            return Err(anyhow!("alias registry builder has already been built"));
+        }
+
+        self.built = true;
+        Ok(RegorusAliasRegistry {
+            registry: Arc::new(mem::replace(&mut self.registry, AliasRegistry::new())),
+        })
+    }
+}
+
+/// Frozen, immutable alias registry.
+pub struct RegorusAliasRegistry {
+    registry: Arc<AliasRegistry>,
+}
+
+impl RegorusAliasRegistry {
+    /// Return a shared reference to the inner registry for use by the compiler.
+    pub(crate) fn inner(&self) -> Arc<AliasRegistry> {
+        Arc::clone(&self.registry)
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Builder lifecycle
+// ---------------------------------------------------------------------------
+
+/// Create a new, empty `AliasRegistry` builder.
+///
+/// The caller must eventually call `regorus_alias_registry_builder_drop`.
 #[no_mangle]
-pub extern "C" fn regorus_alias_registry_drop(registry: *mut RegorusAliasRegistry) {
-    if let Ok(r) = to_ref(registry) {
+pub extern "C" fn regorus_alias_registry_builder_new() -> *mut RegorusAliasRegistryBuilder {
+    Box::into_raw(Box::new(RegorusAliasRegistryBuilder::new()))
+}
+
+/// Drop a `RegorusAliasRegistryBuilder`.
+#[no_mangle]
+pub extern "C" fn regorus_alias_registry_builder_drop(builder: *mut RegorusAliasRegistryBuilder) {
+    if let Ok(builder) = to_ref(builder) {
         unsafe {
-            let _ = Box::from_raw(ptr::from_mut(r));
+            let _ = Box::from_raw(ptr::from_mut(builder));
         }
     }
 }
 
 // ---------------------------------------------------------------------------
-// Loading
+// Builder loading
 // ---------------------------------------------------------------------------
 
-/// Load control-plane alias data (array of `ProviderAliases`) into the registry.
+/// Load control-plane alias data (array of `ProviderAliases`) into the builder.
 ///
 /// `json` must be a valid null-terminated UTF-8 string containing the JSON
 /// array returned by `Get-AzPolicyAlias` or the static
 /// `ResourceTypesAndAliases.json` file.
 #[no_mangle]
-pub extern "C" fn regorus_alias_registry_load_json(
-    registry: *mut RegorusAliasRegistry,
+pub extern "C" fn regorus_alias_registry_builder_load_json(
+    builder: *mut RegorusAliasRegistryBuilder,
     json: *const c_char,
 ) -> RegorusResult {
     with_unwind_guard(|| {
         let output = || -> Result<()> {
             let json_str = from_c_str(json)?;
-            to_ref(registry)?.registry.load_from_json(&json_str)?;
+            to_ref(builder)?.registry_mut()?.load_from_json(&json_str)?;
             Ok(())
         }();
 
@@ -78,20 +120,20 @@ pub extern "C" fn regorus_alias_registry_load_json(
     })
 }
 
-/// Load a data-plane policy manifest into the registry.
+/// Load a data-plane policy manifest into the builder.
 ///
 /// `json` must be a valid null-terminated UTF-8 string containing a single
 /// `DataPolicyManifest` JSON object.
 #[no_mangle]
-pub extern "C" fn regorus_alias_registry_load_manifest(
-    registry: *mut RegorusAliasRegistry,
+pub extern "C" fn regorus_alias_registry_builder_load_manifest(
+    builder: *mut RegorusAliasRegistryBuilder,
     json: *const c_char,
 ) -> RegorusResult {
     with_unwind_guard(|| {
         let output = || -> Result<()> {
             let json_str = from_c_str(json)?;
-            to_ref(registry)?
-                .registry
+            to_ref(builder)?
+                .registry_mut()?
                 .load_data_policy_manifest_json(&json_str)?;
             Ok(())
         }();
@@ -106,16 +148,52 @@ pub extern "C" fn regorus_alias_registry_load_manifest(
     })
 }
 
+/// Freeze a builder into an immutable `RegorusAliasRegistry`.
+#[no_mangle]
+pub extern "C" fn regorus_alias_registry_builder_build(
+    builder: *mut RegorusAliasRegistryBuilder,
+) -> RegorusResult {
+    with_unwind_guard(|| {
+        let output = || -> Result<*mut RegorusAliasRegistry> {
+            let registry = to_ref(builder)?.build()?;
+            Ok(Box::into_raw(Box::new(registry)))
+        }();
+
+        match output {
+            Ok(registry) => RegorusResult::ok_pointer(registry as *mut c_void),
+            Err(e) => {
+                RegorusResult::err_with_message(RegorusStatus::InvalidArgument, format!("{e}"))
+            }
+        }
+    })
+}
+
 // ---------------------------------------------------------------------------
-// Queries
+// Frozen registry lifecycle
+// ---------------------------------------------------------------------------
+
+/// Drop a `RegorusAliasRegistry`.
+#[no_mangle]
+pub extern "C" fn regorus_alias_registry_drop(registry: *mut RegorusAliasRegistry) {
+    if let Ok(registry) = to_ref(registry) {
+        unsafe {
+            let _ = Box::from_raw(ptr::from_mut(registry));
+        }
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Frozen registry queries
 // ---------------------------------------------------------------------------
 
 /// Return the number of resource types loaded in the alias registry.
 #[no_mangle]
-pub extern "C" fn regorus_alias_registry_len(registry: *mut RegorusAliasRegistry) -> RegorusResult {
+pub extern "C" fn regorus_alias_registry_len(
+    registry: *const RegorusAliasRegistry,
+) -> RegorusResult {
     with_unwind_guard(|| {
         let output = || -> Result<i64> {
-            let len = to_ref(registry)?.registry.len();
+            let len = to_shared_ref(registry)?.registry.len();
             Ok(len as i64)
         }();
 
@@ -134,15 +212,9 @@ pub extern "C" fn regorus_alias_registry_len(registry: *mut RegorusAliasRegistry
 ///
 /// Returns a JSON string:
 /// `{ "resource": <normalized>, "context": <context>, "parameters": <params> }`.
-///
-/// * `resource_json` – raw ARM resource JSON
-/// * `api_version` – API version string (e.g. `"2023-01-01"`), or null to use
-///   the default alias paths
-/// * `context_json` – JSON object for additional context (pass `"{}"` if none)
-/// * `parameters_json` – JSON object of policy parameter values (pass `"{}"` if none)
 #[no_mangle]
 pub extern "C" fn regorus_alias_registry_normalize_and_wrap(
-    registry: *mut RegorusAliasRegistry,
+    registry: *const RegorusAliasRegistry,
     resource_json: *const c_char,
     api_version: *const c_char,
     context_json: *const c_char,
@@ -168,7 +240,7 @@ pub extern "C" fn regorus_alias_registry_normalize_and_wrap(
             let context = regorus::Value::from_json_str(&context_str)?;
             let params = regorus::Value::from_json_str(&params_str)?;
 
-            let wrapped = to_ref(registry)?.registry.normalize_and_wrap(
+            let wrapped = to_shared_ref(registry)?.registry.normalize_and_wrap(
                 &resource,
                 api_ver.as_deref(),
                 Some(context),
@@ -185,14 +257,9 @@ pub extern "C" fn regorus_alias_registry_normalize_and_wrap(
 }
 
 /// Denormalize a previously-normalized resource JSON back to ARM format.
-///
-/// * `normalized_json` – the normalized resource JSON
-/// * `api_version` – API version string, or null to use the default alias paths
-///
-/// Returns the denormalized ARM JSON string.
 #[no_mangle]
 pub extern "C" fn regorus_alias_registry_denormalize(
-    registry: *mut RegorusAliasRegistry,
+    registry: *const RegorusAliasRegistry,
     normalized_json: *const c_char,
     api_version: *const c_char,
 ) -> RegorusResult {
@@ -212,7 +279,7 @@ pub extern "C" fn regorus_alias_registry_denormalize(
 
             let normalized = regorus::Value::from_json_str(&normalized_str)?;
 
-            let result = to_ref(registry)?
+            let result = to_shared_ref(registry)?
                 .registry
                 .denormalize(&normalized, api_ver.as_deref());
             result.to_json_str()
@@ -232,12 +299,10 @@ mod tests {
     use core::ffi::CStr;
     use std::ffi::CString;
 
-    /// Helper: create a C string from a Rust &str.
     fn c(s: &str) -> CString {
         CString::new(s).expect("CString::new failed")
     }
 
-    /// Helper: assert a RegorusResult has Ok status and extract string output.
     fn assert_ok_string(r: &RegorusResult) -> String {
         assert_eq!(r.status, RegorusStatus::Ok, "expected Ok status");
         assert!(!r.output.is_null(), "expected non-null output");
@@ -248,12 +313,51 @@ mod tests {
         s
     }
 
-    /// Helper: assert a RegorusResult has Ok status with integer output.
     fn assert_ok_int(r: &RegorusResult) -> i64 {
         assert_eq!(r.status, RegorusStatus::Ok, "expected Ok status");
         r.int_value
     }
 
+    fn assert_ok_pointer(r: &RegorusResult) -> *mut c_void {
+        assert_eq!(r.status, RegorusStatus::Ok, "expected Ok status");
+        assert!(matches!(
+            r.data_type,
+            crate::common::RegorusDataType::Pointer
+        ));
+        assert!(!r.pointer_value.is_null());
+        r.pointer_value
+    }
+
+    fn build_registry_with_json(json: &str) -> *mut RegorusAliasRegistry {
+        let builder = regorus_alias_registry_builder_new();
+        let json = c(json);
+
+        let r = regorus_alias_registry_builder_load_json(builder, json.as_ptr());
+        assert_eq!(r.status, RegorusStatus::Ok);
+        regorus_result_drop(r);
+
+        let r = regorus_alias_registry_builder_build(builder);
+        let registry = assert_ok_pointer(&r) as *mut RegorusAliasRegistry;
+        regorus_result_drop(r);
+        regorus_alias_registry_builder_drop(builder);
+        registry
+    }
+
+    fn build_registry_with_manifest(json: &str) -> *mut RegorusAliasRegistry {
+        let builder = regorus_alias_registry_builder_new();
+        let json = c(json);
+
+        let r = regorus_alias_registry_builder_load_manifest(builder, json.as_ptr());
+        assert_eq!(r.status, RegorusStatus::Ok);
+        regorus_result_drop(r);
+
+        let r = regorus_alias_registry_builder_build(builder);
+        let registry = assert_ok_pointer(&r) as *mut RegorusAliasRegistry;
+        regorus_result_drop(r);
+        regorus_alias_registry_builder_drop(builder);
+        registry
+    }
+
     const ALIASES: &str = r#"[{
         "namespace": "Microsoft.Storage",
         "resourceTypes": [{
@@ -279,20 +383,21 @@ mod tests {
     }"#;
 
     #[test]
-    fn lifecycle_new_and_drop() {
-        let reg = regorus_alias_registry_new();
-        assert!(!reg.is_null());
-        regorus_alias_registry_drop(reg);
+    fn lifecycle_builder_build_and_drop() {
+        let builder = regorus_alias_registry_builder_new();
+        assert!(!builder.is_null());
+
+        let r = regorus_alias_registry_builder_build(builder);
+        let registry = assert_ok_pointer(&r) as *mut RegorusAliasRegistry;
+        regorus_result_drop(r);
+
+        regorus_alias_registry_builder_drop(builder);
+        regorus_alias_registry_drop(registry);
     }
 
     #[test]
     fn load_json_and_check_len() {
-        let reg = regorus_alias_registry_new();
-        let json = c(ALIASES);
-
-        let r = regorus_alias_registry_load_json(reg, json.as_ptr());
-        assert_eq!(r.status, RegorusStatus::Ok);
-        regorus_result_drop(r);
+        let reg = build_registry_with_json(ALIASES);
 
         let r = regorus_alias_registry_len(reg);
         assert_eq!(assert_ok_int(&r), 1);
@@ -303,12 +408,7 @@ mod tests {
 
     #[test]
     fn load_manifest_and_check_len() {
-        let reg = regorus_alias_registry_new();
-        let json = c(MANIFEST);
-
-        let r = regorus_alias_registry_load_manifest(reg, json.as_ptr());
-        assert_eq!(r.status, RegorusStatus::Ok);
-        regorus_result_drop(r);
+        let reg = build_registry_with_manifest(MANIFEST);
 
         let r = regorus_alias_registry_len(reg);
         assert_eq!(assert_ok_int(&r), 1);
@@ -319,23 +419,39 @@ mod tests {
 
     #[test]
     fn load_invalid_json_returns_error() {
-        let reg = regorus_alias_registry_new();
+        let builder = regorus_alias_registry_builder_new();
         let bad = c("not valid json");
 
-        let r = regorus_alias_registry_load_json(reg, bad.as_ptr());
+        let r = regorus_alias_registry_builder_load_json(builder, bad.as_ptr());
         assert_ne!(r.status, RegorusStatus::Ok);
         regorus_result_drop(r);
 
-        regorus_alias_registry_drop(reg);
+        regorus_alias_registry_builder_drop(builder);
+    }
+
+    #[test]
+    fn builder_cannot_be_reused_after_build() {
+        let builder = regorus_alias_registry_builder_new();
+        let r = regorus_alias_registry_builder_build(builder);
+        let registry = assert_ok_pointer(&r) as *mut RegorusAliasRegistry;
+        regorus_result_drop(r);
+
+        let aliases = c(ALIASES);
+        let r = regorus_alias_registry_builder_load_json(builder, aliases.as_ptr());
+        assert_ne!(r.status, RegorusStatus::Ok);
+        regorus_result_drop(r);
+
+        let r = regorus_alias_registry_builder_build(builder);
+        assert_ne!(r.status, RegorusStatus::Ok);
+        regorus_result_drop(r);
+
+        regorus_alias_registry_builder_drop(builder);
+        regorus_alias_registry_drop(registry);
     }
 
     #[test]
     fn normalize_and_wrap_round_trip() {
-        let reg = regorus_alias_registry_new();
-        let aliases = c(ALIASES);
-        let r = regorus_alias_registry_load_json(reg, aliases.as_ptr());
-        assert_eq!(r.status, RegorusStatus::Ok);
-        regorus_result_drop(r);
+        let reg = build_registry_with_json(ALIASES);
 
         let resource = c(r#"{
             "name": "acct1",
@@ -346,7 +462,6 @@ mod tests {
         let ctx = c(r#"{"resourceGroup": {"name": "rg1"}}"#);
         let params = c(r#"{"env": "prod"}"#);
 
-        // Normalize
         let r = regorus_alias_registry_normalize_and_wrap(
             reg,
             resource.as_ptr(),
@@ -357,7 +472,6 @@ mod tests {
         let envelope_json = assert_ok_string(&r);
         regorus_result_drop(r);
 
-        // Parse and verify structure
         let envelope: serde_json::Value =
             serde_json::from_str(&envelope_json).expect("invalid JSON output");
         assert!(
@@ -373,16 +487,13 @@ mod tests {
             "envelope missing 'context'"
         );
 
-        // The normalized resource should have lowercased alias fields
         let res = &envelope["resource"];
         assert_eq!(res["supportshttpstrafficonly"], true);
         assert_eq!(res["name"], "acct1");
 
-        // Context and parameters should be passed through
         assert_eq!(envelope["context"]["resourceGroup"]["name"], "rg1");
         assert_eq!(envelope["parameters"]["env"], "prod");
 
-        // Denormalize the resource portion
         let resource_json = serde_json::to_string(&res).expect("serialize resource");
         let norm_cstr = c(&resource_json);
 
@@ -392,7 +503,6 @@ mod tests {
 
         let denorm: serde_json::Value =
             serde_json::from_str(&denorm_json).expect("invalid denorm JSON");
-        // Should be back under properties with restored casing
         assert_eq!(
             denorm["properties"]["supportsHttpsTrafficOnly"], true,
             "expected restored casing under properties"
@@ -403,11 +513,7 @@ mod tests {
 
     #[test]
     fn denormalize_invalid_json_returns_error() {
-        let reg = regorus_alias_registry_new();
-        let aliases = c(ALIASES);
-        let r = regorus_alias_registry_load_json(reg, aliases.as_ptr());
-        assert_eq!(r.status, RegorusStatus::Ok);
-        regorus_result_drop(r);
+        let reg = build_registry_with_json(ALIASES);
 
         let bad = c("not json");
         let api = c("2023-01-01");
@@ -420,11 +526,7 @@ mod tests {
 
     #[test]
     fn normalize_data_plane_manifest() {
-        let reg = regorus_alias_registry_new();
-        let manifest = c(MANIFEST);
-        let r = regorus_alias_registry_load_manifest(reg, manifest.as_ptr());
-        assert_eq!(r.status, RegorusStatus::Ok);
-        regorus_result_drop(r);
+        let reg = build_registry_with_manifest(MANIFEST);
 
         let resource = c(r#"{
             "type": "Microsoft.KeyVault.Data/vaults/certificates",
@@ -453,7 +555,12 @@ mod tests {
 
     #[test]
     fn empty_registry_normalize() {
-        let reg = regorus_alias_registry_new();
+        let builder = regorus_alias_registry_builder_new();
+        let r = regorus_alias_registry_builder_build(builder);
+        let reg = assert_ok_pointer(&r) as *mut RegorusAliasRegistry;
+        regorus_result_drop(r);
+        regorus_alias_registry_builder_drop(builder);
+
         let resource = c(r#"{"name": "test", "type": "Unknown/type", "properties": {"foo": 1}}"#);
         let api = c("");
         let ctx = c("{}");
@@ -470,7 +577,6 @@ mod tests {
         regorus_result_drop(r);
 
         let envelope: serde_json::Value = serde_json::from_str(&json).expect("invalid JSON");
-        // Without aliases, properties should still be flattened
         assert_eq!(envelope["resource"]["foo"], 1);
         assert_eq!(envelope["resource"]["name"], "test");
 

bindings/ffi/src/common.rs

@@ -236,6 +236,10 @@ pub(crate) fn to_ref<'a, T>(t: *mut T) -> Result<&'a mut T> {
     unsafe { t.as_mut().ok_or_else(|| anyhow!("null pointer")) }
 }
 
+pub(crate) fn to_shared_ref<'a, T>(t: *const T) -> Result<&'a T> {
+    unsafe { t.as_ref().ok_or_else(|| anyhow!("null pointer")) }
+}
+
 pub(crate) fn to_regorus_result(r: Result<()>) -> RegorusResult {
     match r {
         Ok(()) => RegorusResult::ok_void(),

bindings/ffi/src/compile.rs

@@ -1,6 +1,6 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT License.
-use crate::common::{from_c_str, RegorusResult, RegorusStatus};
+use crate::common::{from_c_str, to_shared_ref, RegorusResult, RegorusStatus};
 use crate::compiled_policy::RegorusCompiledPolicy;
 use crate::panic_guard::with_unwind_guard;
 use alloc::boxed::Box;
@@ -208,6 +208,220 @@ fn convert_c_modules_to_rust(
     Ok(policy_modules)
 }
 
+// ---------------------------------------------------------------------------
+// Azure Policy JSON compilation
+// ---------------------------------------------------------------------------
+
+/// Compile an Azure Policy JSON policy rule into an RVM program.
+///
+/// Parses the JSON `policyRule` (the `{ "if": ..., "then": ... }` object),
+/// resolves aliases using the provided registry, and compiles the result
+/// into an RVM [`Program`] that can be loaded into a [`RegorusRvm`].
+///
+/// # Parameters
+/// * `registry` - Alias registry handle, or null.
+/// * `policy_rule_json` - JSON string containing the policyRule object
+///
+/// # Null registry behavior
+///
+/// When `registry` is null, compilation proceeds **without alias resolution**.
+/// Field references that correspond to Azure resource provider aliases
+/// (e.g. `Microsoft.Storage/storageAccounts/supportsHttpsTrafficOnly`) will
+/// be compiled as raw property paths rather than being resolved to their
+/// short forms.  This means:
+///
+/// - Policies that rely on aliases will **silently produce incorrect
+///   evaluation results** because the field paths won't match the
+///   normalized resource structure.
+/// - **Modify / Append** effect policies will **skip the modifiability
+///   validation** that normally rejects writes to non-modifiable aliases
+///   at compile time.
+///
+/// Pass null only when the policy is known to contain no alias references
+/// (e.g. simple `type` / `location` checks, or in unit-test scenarios).
+///
+/// # Returns
+/// Returns a `RegorusResult` containing a `RegorusProgram` pointer on success.
+///
+/// # Safety
+/// `policy_rule_json` must be a valid null-terminated UTF-8 string.
+/// If `registry` is non-null it must be a valid `RegorusAliasRegistry` pointer.
+/// The caller must eventually call `regorus_program_drop` on the returned handle.
+#[cfg(all(feature = "azure_policy", feature = "rvm"))]
+#[no_mangle]
+pub extern "C" fn regorus_compile_azure_policy_rule(
+    registry: *const crate::alias_registry::RegorusAliasRegistry,
+    policy_rule_json: *const c_char,
+) -> RegorusResult {
+    use crate::alias_registry::RegorusAliasRegistry;
+    use crate::rvm::RegorusProgram;
+    use alloc::sync::Arc;
+    use regorus::languages::azure_policy::{compiler, parser};
+    use regorus::Rc;
+    use regorus::Source;
+
+    with_unwind_guard(|| {
+        let result = || -> Result<RegorusProgram, (RegorusStatus, alloc::string::String)> {
+            let json_str = from_c_str(policy_rule_json).map_err(|e| {
+                (
+                    RegorusStatus::InvalidDataFormat,
+                    format!("Invalid policy rule JSON string: {e}"),
+                )
+            })?;
+
+            let source = Source::from_contents("policy_rule".into(), json_str).map_err(|e| {
+                (
+                    RegorusStatus::InvalidDataFormat,
+                    format!("Failed to create source: {e}"),
+                )
+            })?;
+
+            let ast = parser::parse_policy_rule(&source).map_err(|e| {
+                (
+                    RegorusStatus::InvalidPolicy,
+                    format!("Failed to parse policy rule: {e}"),
+                )
+            })?;
+
+            let program = if registry.is_null() {
+                compiler::compile_policy_rule(&ast)
+            } else {
+                let reg: &RegorusAliasRegistry = to_shared_ref(registry).map_err(|e| {
+                    (
+                        RegorusStatus::InvalidArgument,
+                        format!("Invalid alias registry: {e}"),
+                    )
+                })?;
+                compiler::compile_policy_rule_with_aliases(&ast, reg.inner())
+            };
+
+            program
+                .map(|p| RegorusProgram {
+                    program: Arc::new(Rc::try_unwrap(p).unwrap_or_else(|rc| (*rc).clone())),
+                })
+                .map_err(|e| {
+                    (
+                        RegorusStatus::CompilationFailed,
+                        format!("Failed to compile policy rule: {e}"),
+                    )
+                })
+        }();
+
+        match result {
+            Ok(program) => {
+                RegorusResult::ok_pointer(Box::into_raw(Box::new(program)) as *mut c_void)
+            }
+            Err((status, msg)) => RegorusResult::err_with_message(status, msg),
+        }
+    })
+}
+
+/// Compile a full Azure Policy definition JSON into an RVM program.
+///
+/// Parses the JSON policy definition (which includes `policyRule`, `parameters`,
+/// `displayName`, etc.), resolves aliases using the provided registry, and
+/// compiles the result into an RVM [`Program`].
+///
+/// The definition JSON may be in either wrapped or unwrapped form:
+/// - **Wrapped**: `{ "properties": { "policyRule": ..., "parameters": ... }, "id": ... }`
+/// - **Unwrapped**: `{ "policyRule": ..., "parameters": ..., "displayName": ... }`
+///
+/// # Parameters
+/// * `registry` - Alias registry handle, or null.
+/// * `policy_definition_json` - JSON string containing the full policy definition
+///
+/// # Null registry behavior
+///
+/// When `registry` is null, compilation proceeds **without alias resolution**.
+/// Field references that correspond to Azure resource provider aliases will
+/// be compiled as raw property paths rather than being resolved.  This means:
+///
+/// - Policies that rely on aliases will **silently produce incorrect
+///   evaluation results**.
+/// - **Modify / Append** effect policies will **skip the modifiability
+///   validation** that normally rejects writes to non-modifiable aliases
+///   at compile time.
+///
+/// Pass null only when the policy is known to contain no alias references
+/// (e.g. simple `type` / `location` checks, or in unit-test scenarios).
+///
+/// # Returns
+/// Returns a `RegorusResult` containing a `RegorusProgram` pointer on success.
+///
+/// # Safety
+/// `policy_definition_json` must be a valid null-terminated UTF-8 string.
+/// If `registry` is non-null it must be a valid `RegorusAliasRegistry` pointer.
+/// The caller must eventually call `regorus_program_drop` on the returned handle.
+#[cfg(all(feature = "azure_policy", feature = "rvm"))]
+#[no_mangle]
+pub extern "C" fn regorus_compile_azure_policy_definition(
+    registry: *const crate::alias_registry::RegorusAliasRegistry,
+    policy_definition_json: *const c_char,
+) -> RegorusResult {
+    use crate::alias_registry::RegorusAliasRegistry;
+    use crate::rvm::RegorusProgram;
+    use alloc::sync::Arc;
+    use regorus::languages::azure_policy::{compiler, parser};
+    use regorus::Rc;
+    use regorus::Source;
+
+    with_unwind_guard(|| {
+        let result = || -> Result<RegorusProgram, (RegorusStatus, alloc::string::String)> {
+            let json_str = from_c_str(policy_definition_json).map_err(|e| {
+                (
+                    RegorusStatus::InvalidDataFormat,
+                    format!("Invalid policy definition JSON string: {e}"),
+                )
+            })?;
+
+            let source =
+                Source::from_contents("policy_definition".into(), json_str).map_err(|e| {
+                    (
+                        RegorusStatus::InvalidDataFormat,
+                        format!("Failed to create source: {e}"),
+                    )
+                })?;
+
+            let defn = parser::parse_policy_definition(&source).map_err(|e| {
+                (
+                    RegorusStatus::InvalidPolicy,
+                    format!("Failed to parse policy definition: {e}"),
+                )
+            })?;
+
+            let program = if registry.is_null() {
+                compiler::compile_policy_definition(&defn)
+            } else {
+                let reg: &RegorusAliasRegistry = to_shared_ref(registry).map_err(|e| {
+                    (
+                        RegorusStatus::InvalidArgument,
+                        format!("Invalid alias registry: {e}"),
+                    )
+                })?;
+                compiler::compile_policy_definition_with_aliases(&defn, reg.inner())
+            };
+
+            program
+                .map(|p| RegorusProgram {
+                    program: Arc::new(Rc::try_unwrap(p).unwrap_or_else(|rc| (*rc).clone())),
+                })
+                .map_err(|e| {
+                    (
+                        RegorusStatus::CompilationFailed,
+                        format!("Failed to compile policy definition: {e}"),
+                    )
+                })
+        }();
+
+        match result {
+            Ok(program) => {
+                RegorusResult::ok_pointer(Box::into_raw(Box::new(program)) as *mut c_void)
+            }
+            Err((status, msg)) => RegorusResult::err_with_message(status, msg),
+        }
+    })
+}
+
 #[cfg(feature = "std")]
 fn report_module_error(index: usize, kind: &str, err: &anyhow::Error) {
     eprintln!("Invalid {} at index {}: {}", kind, index, err);
@@ -215,3 +429,402 @@ fn report_module_error(index: usize, kind: &str, err: &anyhow::Error) {
 
 #[cfg(not(feature = "std"))]
 fn report_module_error(_index: usize, _kind: &str, _err: &anyhow::Error) {}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::common::regorus_result_drop;
+    use core::ffi::CStr;
+    use std::ffi::CString;
+
+    fn c(s: &str) -> CString {
+        CString::new(s).expect("CString::new failed")
+    }
+
+    fn assert_ok_pointer(r: &RegorusResult) -> *mut c_void {
+        assert_eq!(
+            r.status,
+            RegorusStatus::Ok,
+            "expected Ok, got {:?}",
+            r.status
+        );
+        assert!(!r.pointer_value.is_null(), "expected non-null pointer");
+        r.pointer_value
+    }
+
+    #[cfg(all(feature = "azure_policy", feature = "rvm"))]
+    mod azure_policy_json {
+        use super::*;
+        use crate::alias_registry::regorus_alias_registry_drop;
+        use crate::rvm::{
+            regorus_program_drop, regorus_rvm_drop, regorus_rvm_execute_entry_point_by_name,
+            regorus_rvm_load_program, regorus_rvm_new, regorus_rvm_set_context,
+            regorus_rvm_set_input, RegorusProgram,
+        };
+
+        const ALIASES: &str = r#"[{
+            "namespace": "Microsoft.Storage",
+            "resourceTypes": [{
+                "resourceType": "storageAccounts",
+                "aliases": [{
+                    "name": "Microsoft.Storage/storageAccounts/supportsHttpsTrafficOnly",
+                    "defaultPath": "properties.supportsHttpsTrafficOnly",
+                    "paths": []
+                }, {
+                    "name": "Microsoft.Storage/storageAccounts/minimumTlsVersion",
+                    "defaultPath": "properties.minimumTlsVersion",
+                    "paths": []
+                }]
+            }]
+        }]"#;
+
+        const SIMPLE_POLICY_RULE: &str = r#"{
+            "if": {
+                "field": "type",
+                "equals": "Microsoft.Storage/storageAccounts"
+            },
+            "then": { "effect": "audit" }
+        }"#;
+
+        const ALIAS_POLICY_RULE: &str = r#"{
+            "if": {
+                "allOf": [
+                    { "field": "type", "equals": "Microsoft.Storage/storageAccounts" },
+                    { "field": "Microsoft.Storage/storageAccounts/supportsHttpsTrafficOnly", "equals": false }
+                ]
+            },
+            "then": { "effect": "deny" }
+        }"#;
+
+        const POLICY_DEFINITION: &str = r#"{
+            "displayName": "Require HTTPS for storage accounts",
+            "policyType": "Custom",
+            "mode": "Indexed",
+            "parameters": {
+                "effect": {
+                    "type": "String",
+                    "defaultValue": "deny"
+                }
+            },
+            "policyRule": {
+                "if": {
+                    "allOf": [
+                        { "field": "type", "equals": "Microsoft.Storage/storageAccounts" },
+                        { "field": "Microsoft.Storage/storageAccounts/supportsHttpsTrafficOnly", "equals": false }
+                    ]
+                },
+                "then": { "effect": "[parameters('effect')]" }
+            }
+        }"#;
+
+        /// Wrap a normalized resource JSON into the input envelope expected by
+        /// the compiled Azure Policy RVM program.
+        fn wrap_input(resource_json: &str, parameters_json: &str) -> String {
+            format!(r#"{{"resource": {resource_json}, "parameters": {parameters_json}}}"#)
+        }
+
+        fn build_registry_with_json(
+            json: &str,
+        ) -> *mut crate::alias_registry::RegorusAliasRegistry {
+            let builder = crate::alias_registry::regorus_alias_registry_builder_new();
+            let json_c = c(json);
+            let r = crate::alias_registry::regorus_alias_registry_builder_load_json(
+                builder,
+                json_c.as_ptr(),
+            );
+            assert_eq!(r.status, RegorusStatus::Ok);
+            regorus_result_drop(r);
+
+            let r = crate::alias_registry::regorus_alias_registry_builder_build(builder);
+            let registry =
+                assert_ok_pointer(&r) as *mut crate::alias_registry::RegorusAliasRegistry;
+            regorus_result_drop(r);
+            crate::alias_registry::regorus_alias_registry_builder_drop(builder);
+            registry
+        }
+
+        /// Helper: compile a policy rule, execute it with input, and return the
+        /// result string.
+        unsafe fn compile_and_eval_rule(
+            registry: *const crate::alias_registry::RegorusAliasRegistry,
+            policy_rule: &str,
+            input_json: &str,
+        ) -> String {
+            let rule_c = c(policy_rule);
+            let r = regorus_compile_azure_policy_rule(registry, rule_c.as_ptr());
+            let program_ptr = assert_ok_pointer(&r) as *mut RegorusProgram;
+            regorus_result_drop(r);
+
+            let vm = regorus_rvm_new();
+            assert!(!vm.is_null());
+
+            let r = regorus_rvm_load_program(vm, program_ptr);
+            assert_eq!(r.status, RegorusStatus::Ok);
+            regorus_result_drop(r);
+
+            let input_c = c(input_json);
+            let r = regorus_rvm_set_input(vm, input_c.as_ptr());
+            assert_eq!(r.status, RegorusStatus::Ok);
+            regorus_result_drop(r);
+
+            let entry = c("main");
+            let r = regorus_rvm_execute_entry_point_by_name(vm, entry.as_ptr());
+            assert_eq!(r.status, RegorusStatus::Ok, "execute failed");
+            let output = CStr::from_ptr(r.output)
+                .to_str()
+                .expect("invalid UTF-8")
+                .to_string();
+            regorus_result_drop(r);
+
+            regorus_rvm_drop(vm);
+            regorus_program_drop(program_ptr);
+            output
+        }
+
+        #[test]
+        fn compile_simple_rule_no_aliases() {
+            let rule_c = c(SIMPLE_POLICY_RULE);
+            let r = regorus_compile_azure_policy_rule(core::ptr::null_mut(), rule_c.as_ptr());
+            let ptr = assert_ok_pointer(&r);
+            regorus_result_drop(r);
+            regorus_program_drop(ptr as *mut RegorusProgram);
+        }
+
+        #[test]
+        fn compile_rule_with_aliases() {
+            let reg = build_registry_with_json(ALIASES);
+
+            let rule_c = c(ALIAS_POLICY_RULE);
+            let r = regorus_compile_azure_policy_rule(reg, rule_c.as_ptr());
+            let ptr = assert_ok_pointer(&r);
+            regorus_result_drop(r);
+
+            regorus_program_drop(ptr as *mut RegorusProgram);
+            regorus_alias_registry_drop(reg);
+        }
+
+        #[test]
+        fn compile_and_eval_simple_rule_matching() {
+            let input = wrap_input(r#"{"type":"microsoft.storage/storageaccounts"}"#, "{}");
+            let result =
+                unsafe { compile_and_eval_rule(core::ptr::null_mut(), SIMPLE_POLICY_RULE, &input) };
+            let parsed: serde_json::Value =
+                serde_json::from_str(&result).expect("result should be valid JSON");
+            assert_eq!(
+                parsed["effect"], "audit",
+                "expected audit effect, got: {result}"
+            );
+        }
+
+        #[test]
+        fn compile_and_eval_simple_rule_not_matching() {
+            let input = wrap_input(r#"{"type":"microsoft.compute/virtualmachines"}"#, "{}");
+            let result =
+                unsafe { compile_and_eval_rule(core::ptr::null_mut(), SIMPLE_POLICY_RULE, &input) };
+            // When the "if" condition doesn't match, the result should be undefined
+            assert!(
+                result.contains("undefined"),
+                "expected undefined for non-matching input, got: {result}"
+            );
+        }
+
+        #[test]
+        fn compile_and_eval_alias_rule_deny() {
+            let reg = build_registry_with_json(ALIASES);
+
+            // Non-compliant resource: HTTPS not enabled (normalized form)
+            let input = wrap_input(
+                r#"{"type": "microsoft.storage/storageaccounts", "supportshttpstrafficonly": false}"#,
+                "{}",
+            );
+            let result = unsafe { compile_and_eval_rule(reg, ALIAS_POLICY_RULE, &input) };
+            let parsed: serde_json::Value = serde_json::from_str(&result).expect("valid JSON");
+            assert_eq!(parsed["effect"], "deny", "expected deny, got: {result}");
+
+            regorus_alias_registry_drop(reg);
+        }
+
+        #[test]
+        fn compile_and_eval_alias_rule_compliant() {
+            let reg = build_registry_with_json(ALIASES);
+
+            // Compliant resource: HTTPS enabled (normalized form)
+            let input = wrap_input(
+                r#"{"type": "microsoft.storage/storageaccounts", "supportshttpstrafficonly": true}"#,
+                "{}",
+            );
+            let result = unsafe { compile_and_eval_rule(reg, ALIAS_POLICY_RULE, &input) };
+            assert!(
+                result.contains("undefined"),
+                "expected undefined for compliant resource, got: {result}"
+            );
+
+            regorus_alias_registry_drop(reg);
+        }
+
+        #[test]
+        fn compile_definition_no_aliases() {
+            let defn_c = c(POLICY_DEFINITION);
+            let r = regorus_compile_azure_policy_definition(core::ptr::null_mut(), defn_c.as_ptr());
+            let ptr = assert_ok_pointer(&r);
+            regorus_result_drop(r);
+            regorus_program_drop(ptr as *mut RegorusProgram);
+        }
+
+        #[test]
+        fn compile_definition_with_aliases_and_eval() {
+            let reg = build_registry_with_json(ALIASES);
+
+            let defn_c = c(POLICY_DEFINITION);
+            let r = regorus_compile_azure_policy_definition(reg, defn_c.as_ptr());
+            let program_ptr = assert_ok_pointer(&r) as *mut RegorusProgram;
+            regorus_result_drop(r);
+
+            // Evaluate with a non-compliant resource (normalized form, wrapped in envelope)
+            unsafe {
+                let vm = regorus_rvm_new();
+                let r = regorus_rvm_load_program(vm, program_ptr);
+                assert_eq!(r.status, RegorusStatus::Ok);
+                regorus_result_drop(r);
+
+                let input_json = wrap_input(
+                    r#"{"type": "microsoft.storage/storageaccounts", "supportshttpstrafficonly": false}"#,
+                    "{}",
+                );
+                let input = c(&input_json);
+                let r = regorus_rvm_set_input(vm, input.as_ptr());
+                assert_eq!(r.status, RegorusStatus::Ok);
+                regorus_result_drop(r);
+
+                let entry = c("main");
+                let r = regorus_rvm_execute_entry_point_by_name(vm, entry.as_ptr());
+                assert_eq!(r.status, RegorusStatus::Ok);
+                let result = CStr::from_ptr(r.output)
+                    .to_str()
+                    .expect("UTF-8")
+                    .to_string();
+                regorus_result_drop(r);
+
+                let parsed: serde_json::Value = serde_json::from_str(&result).unwrap();
+                // The default parameter value is "deny"
+                assert_eq!(parsed["effect"], "deny", "got: {result}");
+
+                regorus_rvm_drop(vm);
+                regorus_program_drop(program_ptr);
+            }
+
+            regorus_alias_registry_drop(reg);
+        }
+
+        #[test]
+        fn invalid_json_returns_error() {
+            let bad = c("not valid json");
+            let r = regorus_compile_azure_policy_rule(core::ptr::null_mut(), bad.as_ptr());
+            assert_ne!(r.status, RegorusStatus::Ok);
+            regorus_result_drop(r);
+        }
+
+        #[test]
+        fn invalid_definition_returns_error() {
+            let bad = c(r#"{"not": "a policy definition"}"#);
+            let r = regorus_compile_azure_policy_definition(core::ptr::null_mut(), bad.as_ptr());
+            assert_ne!(r.status, RegorusStatus::Ok);
+            regorus_result_drop(r);
+        }
+
+        /// Policy rule that uses a context function (subscription()).
+        const CONTEXT_POLICY_RULE: &str = r#"{
+            "if": {
+                "allOf": [
+                    { "field": "type", "equals": "Microsoft.Storage/storageAccounts" },
+                    { "value": "[subscription().subscriptionId]", "equals": "sub-123" }
+                ]
+            },
+            "then": { "effect": "deny" }
+        }"#;
+
+        #[test]
+        fn context_policy_evaluates_with_set_context() {
+            let rule_c = c(CONTEXT_POLICY_RULE);
+            let r = regorus_compile_azure_policy_rule(core::ptr::null_mut(), rule_c.as_ptr());
+            let program = assert_ok_pointer(&r) as *mut RegorusProgram;
+            regorus_result_drop(r);
+
+            let vm = regorus_rvm_new();
+            assert!(!vm.is_null());
+
+            let r = regorus_rvm_load_program(vm, program);
+            assert_eq!(r.status, RegorusStatus::Ok);
+            regorus_result_drop(r);
+
+            // Set the context with subscription info
+            let context = c(r#"{"subscription": {"subscriptionId": "sub-123"}}"#);
+            let r = regorus_rvm_set_context(vm, context.as_ptr());
+            assert_eq!(r.status, RegorusStatus::Ok);
+            regorus_result_drop(r);
+
+            // Set matching input
+            let input = c(&wrap_input(
+                r#"{"type": "microsoft.storage/storageaccounts"}"#,
+                "{}",
+            ));
+            let r = regorus_rvm_set_input(vm, input.as_ptr());
+            assert_eq!(r.status, RegorusStatus::Ok);
+            regorus_result_drop(r);
+
+            let entry = c("main");
+            let r = regorus_rvm_execute_entry_point_by_name(vm, entry.as_ptr());
+            assert_eq!(r.status, RegorusStatus::Ok);
+            let output = unsafe { CStr::from_ptr(r.output) }.to_str().unwrap();
+            assert!(
+                output.contains("deny"),
+                "expected deny effect with matching context, got: {output}"
+            );
+            regorus_result_drop(r);
+
+            regorus_rvm_drop(vm);
+            regorus_program_drop(program);
+        }
+
+        #[test]
+        fn context_policy_undefined_without_context() {
+            let rule_c = c(CONTEXT_POLICY_RULE);
+            let r = regorus_compile_azure_policy_rule(core::ptr::null_mut(), rule_c.as_ptr());
+            let program = assert_ok_pointer(&r) as *mut RegorusProgram;
+            regorus_result_drop(r);
+
+            let vm = regorus_rvm_new();
+            assert!(!vm.is_null());
+
+            let r = regorus_rvm_load_program(vm, program);
+            assert_eq!(r.status, RegorusStatus::Ok);
+            regorus_result_drop(r);
+
+            // No context set — subscription() will be undefined
+            let input = c(&wrap_input(
+                r#"{"type": "microsoft.storage/storageaccounts"}"#,
+                "{}",
+            ));
+            let r = regorus_rvm_set_input(vm, input.as_ptr());
+            assert_eq!(r.status, RegorusStatus::Ok);
+            regorus_result_drop(r);
+
+            let entry = c("main");
+            let r = regorus_rvm_execute_entry_point_by_name(vm, entry.as_ptr());
+            assert_eq!(r.status, RegorusStatus::Ok);
+            let output = unsafe { CStr::from_ptr(r.output) }.to_str().unwrap();
+            assert!(
+                output.contains("undefined"),
+                "expected undefined without context, got: {output}"
+            );
+            regorus_result_drop(r);
+
+            regorus_rvm_drop(vm);
+            regorus_program_drop(program);
+        }
+    }
+}

bindings/ffi/src/compiled_policy.rs

@@ -39,7 +39,7 @@ pub extern "C" fn regorus_compiled_policy_eval_with_input(
     with_unwind_guard(|| {
         let output = || -> Result<String> {
             let input_value = regorus::Value::from_json_str(&from_c_str(input)?)?;
-            let result = to_ref(compiled_policy)?
+            let result = to_shared_ref(compiled_policy as *const RegorusCompiledPolicy)?
                 .compiled_policy
                 .eval_with_input(input_value)?;
             result.to_json_str()
@@ -65,7 +65,9 @@ pub extern "C" fn regorus_compiled_policy_get_policy_info(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         let output = || -> Result<String> {
-            let info = to_ref(compiled_policy)?.compiled_policy.get_policy_info()?;
+            let info = to_shared_ref(compiled_policy as *const RegorusCompiledPolicy)?
+                .compiled_policy
+                .get_policy_info()?;
             serde_json::to_string(&info)
                 .map_err(|e| anyhow::anyhow!("Failed to serialize policy info: {}", e))
         }();

bindings/ffi/src/engine.rs

@@ -2,7 +2,8 @@
 // Licensed under the MIT License.
 
 use crate::common::{
-    from_c_str, to_ref, to_regorus_result, to_regorus_string_result, RegorusResult, RegorusStatus,
+    from_c_str, to_ref, to_regorus_result, to_regorus_string_result, to_shared_ref, RegorusResult,
+    RegorusStatus,
 };
 use crate::compiled_policy::RegorusCompiledPolicy;
 use crate::limits::RegorusExecutionTimerConfig;
@@ -193,7 +194,7 @@ pub extern "C" fn regorus_engine_new() -> *mut RegorusEngine {
 ///
 #[no_mangle]
 pub extern "C" fn regorus_engine_clone(engine: *mut RegorusEngine) -> *mut RegorusEngine {
-    match to_ref(engine) {
+    match to_shared_ref(engine as *const RegorusEngine) {
         Ok(e) => Box::into_raw(Box::new(e.clone())),
         _ => ptr::null_mut(),
     }
@@ -223,7 +224,7 @@ pub extern "C" fn regorus_engine_add_policy(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         to_regorus_string_result(|| -> Result<String> {
-            let engine = to_ref(engine)?;
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
             let mut guard = engine.try_write()?;
             guard.add_policy(from_c_str(path)?, from_c_str(rego)?)
         }())
@@ -238,7 +239,7 @@ pub extern "C" fn regorus_engine_add_policy_from_file(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         to_regorus_string_result(|| -> Result<String> {
-            let engine = to_ref(engine)?;
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
             let mut guard = engine.try_write()?;
             guard.add_policy_from_file(from_c_str(path)?)
         }())
@@ -256,7 +257,7 @@ pub extern "C" fn regorus_engine_add_data_json(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         to_regorus_result(|| -> Result<()> {
-            let engine = to_ref(engine)?;
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
             let mut guard = engine.try_write()?;
             guard.add_data(regorus::Value::from_json_str(&from_c_str(data)?)?)
         }())
@@ -270,7 +271,7 @@ pub extern "C" fn regorus_engine_add_data_json(
 pub extern "C" fn regorus_engine_get_packages(engine: *mut RegorusEngine) -> RegorusResult {
     with_unwind_guard(|| {
         to_regorus_string_result(|| -> Result<String> {
-            let engine = to_ref(engine)?;
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
             let guard = engine.try_read()?;
             serde_json::to_string_pretty(&guard.get_packages()?).map_err(anyhow::Error::msg)
         }())
@@ -284,7 +285,7 @@ pub extern "C" fn regorus_engine_get_packages(engine: *mut RegorusEngine) -> Reg
 pub extern "C" fn regorus_engine_get_policies(engine: *mut RegorusEngine) -> RegorusResult {
     with_unwind_guard(|| {
         to_regorus_string_result(|| -> Result<String> {
-            let engine = to_ref(engine)?;
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
             let guard = engine.try_read()?;
             guard.get_policies_as_json()
         }())
@@ -299,7 +300,7 @@ pub extern "C" fn regorus_engine_add_data_from_json_file(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         to_regorus_result(|| -> Result<()> {
-            let engine = to_ref(engine)?;
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
             let mut guard = engine.try_write()?;
             guard.add_data(regorus::Value::from_json_file(from_c_str(path)?)?)
         }())
@@ -313,7 +314,7 @@ pub extern "C" fn regorus_engine_add_data_from_json_file(
 pub extern "C" fn regorus_engine_clear_data(engine: *mut RegorusEngine) -> RegorusResult {
     with_unwind_guard(|| {
         to_regorus_result(|| -> Result<()> {
-            let engine = to_ref(engine)?;
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
             let mut guard = engine.try_write()?;
             guard.clear_data();
             Ok(())
@@ -332,7 +333,7 @@ pub extern "C" fn regorus_engine_set_input_json(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         to_regorus_result(|| -> Result<()> {
-            let engine = to_ref(engine)?;
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
             let mut guard = engine.try_write()?;
             guard.set_input(regorus::Value::from_json_str(&from_c_str(input)?)?);
             Ok(())
@@ -348,7 +349,7 @@ pub extern "C" fn regorus_engine_set_input_from_json_file(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         to_regorus_result(|| -> Result<()> {
-            let engine = to_ref(engine)?;
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
             let mut guard = engine.try_write()?;
             guard.set_input(regorus::Value::from_json_file(from_c_str(path)?)?);
             Ok(())
@@ -367,7 +368,7 @@ pub extern "C" fn regorus_engine_eval_query(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         let output = || -> Result<String> {
-            let engine = to_ref(engine)?;
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
             let mut guard = engine.try_write()?;
             let results = guard.eval_query(from_c_str(query)?, false)?;
             Ok(serde_json::to_string_pretty(&results)?)
@@ -390,7 +391,7 @@ pub extern "C" fn regorus_engine_eval_rule(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         let output = || -> Result<String> {
-            let engine = to_ref(engine)?;
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
             let mut guard = engine.try_write()?;
             guard.eval_rule(from_c_str(rule)?)?.to_json_str()
         }();
@@ -413,7 +414,7 @@ pub extern "C" fn regorus_engine_set_enable_coverage(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         to_regorus_result(|| -> Result<()> {
-            let engine = to_ref(engine)?;
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
             let mut guard = engine.try_write()?;
             guard.set_enable_coverage(enable);
             Ok(())
@@ -429,7 +430,7 @@ pub extern "C" fn regorus_engine_set_enable_coverage(
 pub extern "C" fn regorus_engine_get_coverage_report(engine: *mut RegorusEngine) -> RegorusResult {
     with_unwind_guard(|| {
         let output = || -> Result<String> {
-            let engine = to_ref(engine)?;
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
             let guard = engine.try_read()?;
             Ok(serde_json::to_string_pretty(&guard.get_coverage_report()?)?)
         }();
@@ -451,7 +452,7 @@ pub extern "C" fn regorus_engine_set_strict_builtin_errors(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         to_regorus_result(|| -> Result<()> {
-            let engine = to_ref(engine)?;
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
             let mut guard = engine.try_write()?;
             guard.set_strict_builtin_errors(strict);
             Ok(())
@@ -465,18 +466,20 @@ pub extern "C" fn regorus_engine_set_execution_timer_config(
     engine: *mut RegorusEngine,
     config: *const RegorusExecutionTimerConfig,
 ) -> RegorusResult {
-    to_regorus_result(|| -> Result<()> {
-        let engine = to_ref(engine)?;
-        let config = unsafe {
-            config
-                .as_ref()
-                .copied()
-                .ok_or_else(|| anyhow!("execution timer config pointer is null"))?
-        };
-        let mut guard = engine.try_write()?;
-        guard.set_execution_timer_config(config.to_execution_timer_config()?);
-        Ok(())
-    }())
+    with_unwind_guard(|| {
+        to_regorus_result(|| -> Result<()> {
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
+            let config = unsafe {
+                config
+                    .as_ref()
+                    .copied()
+                    .ok_or_else(|| anyhow!("execution timer config pointer is null"))?
+            };
+            let mut guard = engine.try_write()?;
+            guard.set_execution_timer_config(config.to_execution_timer_config()?);
+            Ok(())
+        }())
+    })
 }
 
 #[no_mangle]
@@ -484,12 +487,14 @@ pub extern "C" fn regorus_engine_set_execution_timer_config(
 pub extern "C" fn regorus_engine_clear_execution_timer_config(
     engine: *mut RegorusEngine,
 ) -> RegorusResult {
-    to_regorus_result(|| -> Result<()> {
-        let engine = to_ref(engine)?;
-        let mut guard = engine.try_write()?;
-        guard.clear_execution_timer_config();
-        Ok(())
-    }())
+    with_unwind_guard(|| {
+        to_regorus_result(|| -> Result<()> {
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
+            let mut guard = engine.try_write()?;
+            guard.clear_execution_timer_config();
+            Ok(())
+        }())
+    })
 }
 
 /// Set the policy length limits used when loading policies.
@@ -500,7 +505,7 @@ pub extern "C" fn regorus_engine_set_policy_length_config(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         to_regorus_result(|| -> Result<()> {
-            let engine = to_ref(engine)?;
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
             let mut guard = engine.try_write()?;
             guard.set_policy_length_config(config.to_policy_length_config()?);
             Ok(())
@@ -515,7 +520,7 @@ pub extern "C" fn regorus_engine_clear_policy_length_config(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         to_regorus_result(|| -> Result<()> {
-            let engine = to_ref(engine)?;
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
             let mut guard = engine.try_write()?;
             guard.clear_policy_length_config();
             Ok(())
@@ -533,7 +538,7 @@ pub extern "C" fn regorus_engine_get_coverage_report_pretty(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         let output = || -> Result<String> {
-            let engine = to_ref(engine)?;
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
             let guard = engine.try_read()?;
             guard.get_coverage_report()?.to_string_pretty()
         }();
@@ -552,7 +557,7 @@ pub extern "C" fn regorus_engine_get_coverage_report_pretty(
 pub extern "C" fn regorus_engine_clear_coverage_data(engine: *mut RegorusEngine) -> RegorusResult {
     with_unwind_guard(|| {
         to_regorus_result(|| -> Result<()> {
-            let engine = to_ref(engine)?;
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
             let mut guard = engine.try_write()?;
             guard.clear_coverage_data();
             Ok(())
@@ -571,7 +576,7 @@ pub extern "C" fn regorus_engine_set_gather_prints(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         to_regorus_result(|| -> Result<()> {
-            let engine = to_ref(engine)?;
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
             let mut guard = engine.try_write()?;
             guard.set_gather_prints(enable);
             Ok(())
@@ -586,7 +591,7 @@ pub extern "C" fn regorus_engine_set_gather_prints(
 pub extern "C" fn regorus_engine_take_prints(engine: *mut RegorusEngine) -> RegorusResult {
     with_unwind_guard(|| {
         let output = || -> Result<String> {
-            let engine = to_ref(engine)?;
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
             let mut guard = engine.try_write()?;
             Ok(serde_json::to_string_pretty(&guard.take_prints()?)?)
         }();
@@ -605,7 +610,7 @@ pub extern "C" fn regorus_engine_take_prints(engine: *mut RegorusEngine) -> Rego
 pub extern "C" fn regorus_engine_get_ast_as_json(engine: *mut RegorusEngine) -> RegorusResult {
     with_unwind_guard(|| {
         let output = || -> Result<String> {
-            let engine = to_ref(engine)?;
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
             let guard = engine.try_read()?;
             guard.get_ast_as_json()
         }();
@@ -626,7 +631,7 @@ pub extern "C" fn regorus_engine_get_policy_package_names(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         let output = || -> Result<String> {
-            let engine = to_ref(engine)?;
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
             let guard = engine.try_read()?;
             serde_json::to_string_pretty(&guard.get_policy_package_names()?)
                 .map_err(anyhow::Error::msg)
@@ -648,7 +653,7 @@ pub extern "C" fn regorus_engine_get_policy_parameters(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         let output = || -> Result<String> {
-            let engine = to_ref(engine)?;
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
             let guard = engine.try_read()?;
             serde_json::to_string_pretty(&guard.get_policy_parameters()?)
                 .map_err(anyhow::Error::msg)
@@ -670,7 +675,7 @@ pub extern "C" fn regorus_engine_set_rego_v0(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         let output = || -> Result<()> {
-            let engine = to_ref(engine)?;
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
             let mut guard = engine.try_write()?;
             guard.set_rego_v0(enable);
             Ok(())
@@ -692,7 +697,7 @@ pub extern "C" fn regorus_engine_set_rego_v0(
 #[cfg(feature = "azure_policy")]
 pub extern "C" fn regorus_engine_compile_for_target(engine: *mut RegorusEngine) -> RegorusResult {
     with_unwind_guard(|| {
-        let engine = match to_ref(engine) {
+        let engine = match to_shared_ref(engine as *const RegorusEngine) {
             Ok(engine) => engine,
             Err(e) => {
                 return RegorusResult::err_with_message(
@@ -741,7 +746,7 @@ pub extern "C" fn regorus_engine_compile_with_entrypoint(
         let result = || -> Result<RegorusCompiledPolicy> {
             let rule_str = from_c_str(rule)?;
             let rule_rc: regorus::Rc<str> = rule_str.into();
-            let engine = to_ref(engine)?;
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
             let mut guard = engine.try_write()?;
             let compiled_policy = guard.compile_with_entrypoint(&rule_rc)?;
             Ok(RegorusCompiledPolicy { compiled_policy })
@@ -800,7 +805,7 @@ pub extern "C" fn regorus_engine_compile_program_with_entrypoints(
                 .ok_or_else(|| anyhow!("entry_points must contain at least one entry"))?;
             let rule_rc: regorus::Rc<str> = (*rule).into();
 
-            let engine = to_ref(engine)?;
+            let engine = to_shared_ref(engine as *const RegorusEngine)?;
             let mut guard = engine.try_write()?;
             let compiled_policy = guard.compile_with_entrypoint(&rule_rc)?;
 

bindings/ffi/src/rvm.rs

@@ -2,7 +2,8 @@
 // Licensed under the MIT License.
 
 use crate::common::{
-    from_c_str, to_ref, to_regorus_result, RegorusBuffer, RegorusResult, RegorusStatus,
+    from_c_str, to_ref, to_regorus_result, to_shared_ref, RegorusBuffer, RegorusResult,
+    RegorusStatus,
 };
 use crate::compile::RegorusPolicyModule;
 use crate::compiled_policy::RegorusCompiledPolicy;
@@ -106,7 +107,8 @@ pub extern "C" fn regorus_program_compile_from_policy(
 
             let entry_points_ref: Vec<&str> = entry_points_vec.iter().map(|s| s.as_str()).collect();
 
-            let compiled_policy = &to_ref(compiled_policy)?.compiled_policy;
+            let compiled_policy =
+                &to_shared_ref(compiled_policy as *const RegorusCompiledPolicy)?.compiled_policy;
             let program = Compiler::compile_from_policy(compiled_policy, &entry_points_ref)?;
             Ok(Box::into_raw(Box::new(RegorusProgram { program })))
         }();
@@ -187,7 +189,7 @@ pub extern "C" fn regorus_program_new() -> *mut RegorusProgram {
 pub extern "C" fn regorus_program_serialize_binary(program: *mut RegorusProgram) -> RegorusResult {
     with_unwind_guard(|| {
         let output = || -> Result<*mut RegorusBuffer> {
-            let program = &to_ref(program)?.program;
+            let program = &to_shared_ref(program as *const RegorusProgram)?.program;
             let bytes = program.serialize_binary().map_err(|e| anyhow!(e))?;
             Ok(RegorusBuffer::from_vec(bytes))
         }();
@@ -211,7 +213,10 @@ pub extern "C" fn regorus_program_deserialize_binary(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         let output = || -> Result<(*mut RegorusProgram, bool)> {
-            if data.is_null() && len > 0 {
+            if data.is_null() {
+                if len > 0 {
+                    return Err(anyhow!("null data pointer with non-zero length"));
+                }
                 return Err(anyhow!("null data pointer"));
             }
             let data = unsafe { core::slice::from_raw_parts(data, len) };
@@ -249,7 +254,7 @@ pub extern "C" fn regorus_program_deserialize_binary(
 pub extern "C" fn regorus_program_generate_listing(program: *mut RegorusProgram) -> RegorusResult {
     with_unwind_guard(|| {
         let output = || -> Result<String> {
-            let program = &to_ref(program)?.program;
+            let program = &to_shared_ref(program as *const RegorusProgram)?.program;
             Ok(generate_assembly_listing(
                 program,
                 &AssemblyListingConfig::default(),
@@ -270,7 +275,7 @@ pub extern "C" fn regorus_program_generate_tabular_listing(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         let output = || -> Result<String> {
-            let program = &to_ref(program)?.program;
+            let program = &to_shared_ref(program as *const RegorusProgram)?.program;
             Ok(generate_tabular_assembly_listing(
                 program,
                 &AssemblyListingConfig::default(),
@@ -297,7 +302,9 @@ pub extern "C" fn regorus_rvm_new_with_policy(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         let output = || -> Result<*mut RegorusRvm> {
-            let policy = to_ref(compiled_policy)?.compiled_policy.clone();
+            let policy = to_shared_ref(compiled_policy as *const RegorusCompiledPolicy)?
+                .compiled_policy
+                .clone();
             Ok(Box::into_raw(Box::new(RegorusRvm::new(
                 RegoVM::new_with_policy(policy),
             ))))
@@ -318,9 +325,11 @@ pub extern "C" fn regorus_rvm_load_program(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         to_regorus_result(|| -> Result<()> {
-            let vm = to_ref(vm)?;
+            let vm = to_shared_ref(vm as *const RegorusRvm)?;
             let mut guard = vm.try_write()?;
-            let program = to_ref(program)?.program.clone();
+            let program = to_shared_ref(program as *const RegorusProgram)?
+                .program
+                .clone();
             guard.load_program(program);
             Ok(())
         }())
@@ -332,7 +341,7 @@ pub extern "C" fn regorus_rvm_load_program(
 pub extern "C" fn regorus_rvm_set_data(vm: *mut RegorusRvm, data: *const c_char) -> RegorusResult {
     with_unwind_guard(|| {
         to_regorus_result(|| -> Result<()> {
-            let vm = to_ref(vm)?;
+            let vm = to_shared_ref(vm as *const RegorusRvm)?;
             let mut guard = vm.try_write()?;
             let data_value = Value::from_json_str(&from_c_str(data)?)?;
             guard.set_data(data_value)?;
@@ -349,7 +358,7 @@ pub extern "C" fn regorus_rvm_set_input(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         to_regorus_result(|| -> Result<()> {
-            let vm = to_ref(vm)?;
+            let vm = to_shared_ref(vm as *const RegorusRvm)?;
             let mut guard = vm.try_write()?;
             let input_value = Value::from_json_str(&from_c_str(input)?)?;
             guard.set_input(input_value);
@@ -358,6 +367,33 @@ pub extern "C" fn regorus_rvm_set_input(
     })
 }
 
+/// Set the VM context document from JSON.
+///
+/// The context provides host-supplied ambient data (e.g. `resourceGroup()`,
+/// `subscription()`) that Azure Policy functions can access via `LoadContext`
+/// instructions. This must be called before `regorus_rvm_execute` when
+/// evaluating policies that reference context functions.
+///
+/// # Safety
+/// - `vm` must be a valid pointer to a `RegorusRvm` created by `regorus_rvm_new`.
+/// - `context_json` must be a valid null-terminated UTF-8 string.
+#[cfg(feature = "azure_policy")]
+#[no_mangle]
+pub extern "C" fn regorus_rvm_set_context(
+    vm: *mut RegorusRvm,
+    context_json: *const c_char,
+) -> RegorusResult {
+    with_unwind_guard(|| {
+        to_regorus_result(|| -> Result<()> {
+            let vm = to_shared_ref(vm as *const RegorusRvm)?;
+            let mut guard = vm.try_write()?;
+            let context_value = Value::from_json_str(&from_c_str(context_json)?)?;
+            guard.set_context(context_value);
+            Ok(())
+        }())
+    })
+}
+
 /// Set the maximum number of instructions that can execute.
 #[no_mangle]
 pub extern "C" fn regorus_rvm_set_max_instructions(
@@ -366,7 +402,7 @@ pub extern "C" fn regorus_rvm_set_max_instructions(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         to_regorus_result(|| -> Result<()> {
-            let vm = to_ref(vm)?;
+            let vm = to_shared_ref(vm as *const RegorusRvm)?;
             let mut guard = vm.try_write()?;
             guard.set_max_instructions(max_instructions);
             Ok(())
@@ -382,7 +418,7 @@ pub extern "C" fn regorus_rvm_set_strict_builtin_errors(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         to_regorus_result(|| -> Result<()> {
-            let vm = to_ref(vm)?;
+            let vm = to_shared_ref(vm as *const RegorusRvm)?;
             let mut guard = vm.try_write()?;
             guard.set_strict_builtin_errors(strict);
             Ok(())
@@ -395,7 +431,7 @@ pub extern "C" fn regorus_rvm_set_strict_builtin_errors(
 pub extern "C" fn regorus_rvm_set_execution_mode(vm: *mut RegorusRvm, mode: u8) -> RegorusResult {
     with_unwind_guard(|| {
         to_regorus_result(|| -> Result<()> {
-            let vm = to_ref(vm)?;
+            let vm = to_shared_ref(vm as *const RegorusRvm)?;
             let mut guard = vm.try_write()?;
             let mode = match mode {
                 0 => ExecutionMode::RunToCompletion,
@@ -413,7 +449,7 @@ pub extern "C" fn regorus_rvm_set_execution_mode(vm: *mut RegorusRvm, mode: u8)
 pub extern "C" fn regorus_rvm_set_step_mode(vm: *mut RegorusRvm, enabled: bool) -> RegorusResult {
     with_unwind_guard(|| {
         to_regorus_result(|| -> Result<()> {
-            let vm = to_ref(vm)?;
+            let vm = to_shared_ref(vm as *const RegorusRvm)?;
             let mut guard = vm.try_write()?;
             guard.set_step_mode(enabled);
             Ok(())
@@ -430,7 +466,7 @@ pub extern "C" fn regorus_rvm_set_execution_timer_config(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         to_regorus_result(|| -> Result<()> {
-            let vm = to_ref(vm)?;
+            let vm = to_shared_ref(vm as *const RegorusRvm)?;
             let mut guard = vm.try_write()?;
             if has_config {
                 guard.set_execution_timer_config(Some(config.to_execution_timer_config()?));
@@ -447,7 +483,7 @@ pub extern "C" fn regorus_rvm_set_execution_timer_config(
 pub extern "C" fn regorus_rvm_execute(vm: *mut RegorusRvm) -> RegorusResult {
     with_unwind_guard(|| {
         let output = || -> Result<String> {
-            let vm = to_ref(vm)?;
+            let vm = to_shared_ref(vm as *const RegorusRvm)?;
             let mut guard = vm.try_write()?;
             let result = guard.execute()?;
             result.to_json_str()
@@ -468,7 +504,7 @@ pub extern "C" fn regorus_rvm_execute_entry_point_by_name(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         let output = || -> Result<String> {
-            let vm = to_ref(vm)?;
+            let vm = to_shared_ref(vm as *const RegorusRvm)?;
             let mut guard = vm.try_write()?;
             let name = from_c_str(entry_point)?;
             let result = guard.execute_entry_point_by_name(&name)?;
@@ -490,7 +526,7 @@ pub extern "C" fn regorus_rvm_execute_entry_point_by_index(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         let output = || -> Result<String> {
-            let vm = to_ref(vm)?;
+            let vm = to_shared_ref(vm as *const RegorusRvm)?;
             let mut guard = vm.try_write()?;
             let result = guard.execute_entry_point_by_index(index)?;
             result.to_json_str()
@@ -512,7 +548,7 @@ pub extern "C" fn regorus_rvm_resume(
 ) -> RegorusResult {
     with_unwind_guard(|| {
         let output = || -> Result<String> {
-            let vm = to_ref(vm)?;
+            let vm = to_shared_ref(vm as *const RegorusRvm)?;
             let mut guard = vm.try_write()?;
             let value = if has_value {
                 Some(Value::from_json_str(&from_c_str(resume_value_json)?)?)
@@ -535,7 +571,7 @@ pub extern "C" fn regorus_rvm_resume(
 pub extern "C" fn regorus_rvm_get_execution_state(vm: *mut RegorusRvm) -> RegorusResult {
     with_unwind_guard(|| {
         let output = || -> Result<String> {
-            let vm = to_ref(vm)?;
+            let vm = to_shared_ref(vm as *const RegorusRvm)?;
             let guard = vm.try_read()?;
             let state: ExecutionState = guard.execution_state().clone();
             Ok(format!("{:?}", state))

bindings/java/src/lib.rs

@@ -462,7 +462,7 @@ pub extern "system" fn Java_com_microsoft_regorus_Program_nativeCompileFromModul
         }
 
         let mut modules = Vec::with_capacity(ids.len());
-        for (id, content) in ids.into_iter().zip(contents.into_iter()) {
+        for (id, content) in ids.into_iter().zip(contents) {
             modules.push(PolicyModule {
                 id: Rc::from(id.as_str()),
                 content: Rc::from(content.as_str()),

src/compiler/destructuring_planner/assignment.rs

@@ -314,7 +314,7 @@ fn order_element_pairs<T: VariableBindingContext>(
 
             if ready {
                 let (value_expr, plan, _deps, binds) = remaining.remove(idx);
-                scheduled.extend(binds.into_iter());
+                scheduled.extend(binds);
                 ordered.push((value_expr, plan));
                 progress = true;
                 break;

src/languages/azure_policy/parser/policy_definition.rs

@@ -264,18 +264,17 @@ impl<'source> Parser<'source> {
             "metadata" => {
                 *metadata = Some(self.parse_json_value()?);
             }
-            "parameters" => {
+            "parameters" if self.token_text() == "{" => {
                 // Parameters must be a JSON object; if not, push to extra.
-                if self.token_text() == "{" {
-                    *parameters = self.parse_parameter_definitions()?;
-                } else {
-                    let value = self.parse_json_value()?;
-                    extra.push(ObjectEntry {
-                        key_span,
-                        key: key.into(),
-                        value,
-                    });
-                }
+                *parameters = self.parse_parameter_definitions()?;
+            }
+            "parameters" => {
+                let value = self.parse_json_value()?;
+                extra.push(ObjectEntry {
+                    key_span,
+                    key: key.into(),
+                    value,
+                });
             }
             "policyrule" => {
                 // Parse the policyRule directly from the token stream!

src/tests/scheduler/analyzer/mod.rs

@@ -88,7 +88,7 @@ fn analyze_file(regos: &[String], expected_scopes: &[Scope]) -> Result<()> {
         }
     }
 
-    scopes.sort_by(|a, b| a.0.span.line.cmp(&b.0.span.line));
+    scopes.sort_by_key(|a| a.0.span.line);
     for (idx, (_, scope)) in scopes.iter().enumerate() {
         if idx > expected_scopes.len() {
             bail!("extra scope generated.")