Adding EnumMethodDefinitionByName, StartEnumMethodDefinitionsByName, and EndEnumMethodDefinitionsByName cDAC APIs by rcj1 · Pull Request #125539 · dotnet/runtime

rcj1 · 2026-03-13T22:21:58Z

Tested locally by using bpmd on various methods (including ctors, and with and without specified namespace) and ensuring that they bind and pass debug validation.

dotnet-policy-service · 2026-03-13T22:23:09Z

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Copilot

Pull request overview

This PR adds cDAC-backed support for enumerating method definitions by name through the legacy IXCLRDataModule COM surface, enabling name-based method lookup via ECMA-335 metadata.

Changes:

Introduces CLRDataByNameFlag to represent by-name lookup options (case sensitivity).
Implements StartEnumMethodDefinitionsByName / EnumMethodDefinitionByName / EndEnumMethodDefinitionsByName in ClrDataModule using MetadataReader.
Adds a new ClrDataMethodDefinition COM class to represent returned method-definition objects.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 4 comments.

File	Description
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/IXCLRData.cs	Adds `CLRDataByNameFlag` enum for by-name enumeration flags.
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/ClrDataModule.cs	Implements cDAC-based method-definition-by-name enumeration, maintaining optional sync with legacy DAC in DEBUG.
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/ClrDataMethodDefinition.cs	Introduces a COM class intended to represent method definitions returned by the new enumeration.

src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/ClrDataModule.cs

...tive/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/ClrDataMethodDefinition.cs

noahfalk

This looks fine to me modulo adding a bunch of test cases to verify/document that the name syntax supported here is exactly the same as what the DAC implementation supports.

noahfalk · 2026-03-14T08:41:02Z

src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/ClrDataModule.cs

+            _flags = flags;
+        }
+
+        public void Start(string fullName)


Can you add test cases that pass in a wide variety of different names - it serves both as documentation of the syntax and verification that it matches what the DAC did. These type name parsers can have irritating levels of detail in what they accept and how they expect it to be formatted. As much as possible I try to keep name parsing/formatting out of the API surface but I know for compat we don't have a choice here. They can be bug farms if not thoroughly specified and tested. For instance:

are namespaces required?

are type aliases allowed? ('int' vs 'Int32')

are generic type parameters supported?

if so do they use backtick {arity} notation, square bracket notation, or angle bracket notation?

are open and closed definitions supported? If closed definitions are supported are generic parameter types parsed with the exact same rules as the outer type?

are closed definitions that refer to enclosing scope generic variables (!0, !!0) supported?

are type parameter names supported?

if both a nested class and its enclosing class have generic parameters, which parameters are attributed to each

are pointer, array, and by ref types supported? (and how encoded if so)

are method parameters, calling convention, or return value types considered? If so do they follow the same type formatting rules as the declaring type for the method?

No need to answer them as text, but hopefully the test cases would verify all of this

Namespaces are optional

Type aliases are not allowed

Generic type parameters are supported only with backtick notation. Closed definitions and parameter names are not supported

The breakpoint can be set, but Windbg crashes after hitting a breakpoint on say, System.Array.Clone. windbg-stacktrace.txt

Parameters are ignored, and calling convention and return value types must not be typed. Only the name of the method is allowed and
processed.

The docs specify that you need the "method name". I'm wondering if we should be more specific about this. Perhaps adding something like "Method parameters will be ignored (bpmd binds to all overloaded methods)."

Copilot

Pull request overview

Adds cDAC support for enumerating method definitions by name in the legacy IXCLRData COM surface, enabling scenarios like bpmd to bind methods via metadata-based lookup.

Changes:

Introduces CLRDataByNameFlag for case-sensitivity options used by by-name enumeration.
Implements StartEnumMethodDefinitionsByName, EnumMethodDefinitionByName, and EndEnumMethodDefinitionsByName in ClrDataModule using ECMA-335 metadata, while keeping legacy enumeration in sync for debug validation.
Adds a new COM class ClrDataMethodDefinition as the managed representation returned by the enumeration.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

File	Description
`src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/IXCLRData.cs`	Adds `CLRDataByNameFlag` used by the new by-name enumeration APIs.
`src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/ClrDataModule.cs`	Implements metadata-backed method-definition-by-name enumeration and handle management.
`src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/ClrDataMethodDefinition.cs`	Adds a COM class to represent enumerated method definitions (currently legacy-delegating).

...tive/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/ClrDataMethodDefinition.cs

src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/ClrDataModule.cs

Copilot

Pull request overview

Adds cDAC support for enumerating method definitions by name in the Legacy IXCLRData layer, along with targeted unit tests that validate name parsing and matching behaviors against synthetic metadata.

Changes:

Introduces CLRDataByNameFlag and implements StartEnumMethodDefinitionsByName / EnumMethodDefinitionByName / EndEnumMethodDefinitionsByName in ClrDataModule.
Adds a new ClrDataMethodDefinition COM class wrapper for returned method definitions.
Adds EnumMethodDefinitionsTests covering type/method name parsing (namespaces optional, nested types, generics, constructors, case sensitivity, overload counts).

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 5 comments.

File	Description
src/native/managed/cdac/tests/EnumMethodDefinitionsTests.cs	Adds synthetic-metadata unit tests for method-by-name parsing/matching and expected enumeration counts.
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/IXCLRData.cs	Adds `CLRDataByNameFlag` to model native `CLRDATA_BYNAME_*` flags.
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/ClrDataModule.cs	Implements the module-level method-definition-by-name enumeration using ECMA metadata, with legacy cross-validation/fallback plumbing.
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/ClrDataMethodDefinition.cs	Adds a new COM class wrapper for `IXCLRDataMethodDefinition` results (currently legacy-forwarding).

...tive/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/ClrDataMethodDefinition.cs

src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/ClrDataModule.cs

src/native/managed/cdac/tests/EnumMethodDefinitionsTests.cs

Copilot

Pull request overview

Adds cDAC support for enumerating method definitions by name in the legacy IXCLRDataModule COM surface, including flag definitions and a focused unit test validating name parsing and matching behavior.

Changes:

Implement StartEnumMethodDefinitionsByName, EnumMethodDefinitionByName, and EndEnumMethodDefinitionsByName in ClrDataModule.
Introduce CLRDataByNameFlag for case-sensitivity control.
Add unit tests with synthetic ECMA-335 metadata to validate name parsing (namespace optionality, nesting separators, constructors, overloads, case-insensitive matching).

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 7 comments.

File	Description
src/native/managed/cdac/tests/EnumMethodDefinitionsTests.cs	Adds unit tests using synthetic metadata to validate method-name parsing/matching behavior.
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/IXCLRData.cs	Introduces `CLRDataByNameFlag` used by the new enumeration APIs.
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/ClrDataModule.cs	Implements the new “enum method definitions by name” APIs and associated helper enumerator.
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/ClrDataMethodDefinition.cs	Adds a COM wrapper type returned by enumeration (`IXCLRDataMethodDefinition`).

src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/ClrDataModule.cs

+            GCHandle gcHandle = GCHandle.FromIntPtr((IntPtr)handle);
+            if (gcHandle.Target is not EnumMethodDefinitions emdLocal)
+                throw new ArgumentException();
+            emd = emdLocal;
+            emd.MethodEnumerator.Dispose();
+            gcHandle.Free();


...tive/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/ClrDataMethodDefinition.cs

+using System;
+using System.Runtime.InteropServices.Marshalling;
+using Microsoft.Diagnostics.DataContractReader.Contracts;


...tive/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/ClrDataMethodDefinition.cs

+    private readonly Target _target;
+    private readonly TargetPointer _module;
+    private readonly uint _token;
+    private readonly IXCLRDataMethodDefinition? _legacyImpl;
+    public ClrDataMethodDefinition(
+        Target target,
+        TargetPointer module,
+        uint token,
+        IXCLRDataMethodDefinition? legacyImpl)
+    {
+        _target = target;
+        _module = module;
+        _token = token;
+        _legacyImpl = legacyImpl;


src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/ClrDataModule.cs

rcj1 · 2026-03-14T19:35:41Z

src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/ClrDataModule.cs

+                string typePortion = fullName[..dotPos];
+                string methodName = fullName[Math.Min(dotPos + 1, fullName.Length - 1)..];
+
+                _typeHandle = ResolveType(_reader, typePortion);
+                if (_typeHandle != null)
+                {
+                    _methodName = methodName;
+                    break;
+                }
+
+                searchFrom = dotPos - 1;
+            }
+
+            if (_typeHandle == null)
+                throw new ArgumentException();
+            MethodEnumerator = IterateMethodInstances().GetEnumerator();


Exactly. The start method is supposed to validate the type, not the method name.

src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/ClrDataModule.cs

+        try
+        {
+            if (method.IsNullRef)
+                throw new NullReferenceException();
+            GCHandle gcHandle = GCHandle.FromIntPtr((IntPtr)(*handle));
+            if (gcHandle.Target is not EnumMethodDefinitions emdLocal)
+                throw new ArgumentException("Type not found");
+
+            emd = emdLocal;
+        }
+        catch (System.Exception ex)
+        {
+            return ex.HResult;
+        }
+


src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/ClrDataModule.cs

+            if (emd.MethodEnumerator.MoveNext())
+            {
+                uint token = emd.MethodEnumerator.Current;
+                method.Interface = new ClrDataMethodDefinition(_target, _address, token, legacyMethod);


adding EnumMethodDefinitionByName etc

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Copilot AI review requested due to automatic review settings March 13, 2026 22:21

github-actions bot added the area-Diagnostics-coreclr label Mar 13, 2026

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rcj1 requested review from barosiak, hoyosjs, max-charlamb and noahfalk March 13, 2026 23:31

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rcj1 marked this pull request as draft March 14, 2026 16:47

adding tests

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rcj1 marked this pull request as ready for review March 14, 2026 18:25

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rcj1 force-pushed the EnumMethodDefinitionByName branch from a98cfa7 to 7cb5ac8 Compare March 14, 2026 19:34

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rcj1 force-pushed the EnumMethodDefinitionByName branch from 7cb5ac8 to 55ab5de Compare March 14, 2026 19:38

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rcj1 commented Mar 13, 2026 •

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