Convert priority 3 MethodDescCallSite calls to UnmanagedCallersOnly by steveisok · Pull Request #124854 · dotnet/runtime

steveisok · 2026-02-25T12:48:35Z

First set of priority 3 conversions from #123864 — replace MethodDescCallSite/CallDescrWorker calls with UnmanagedCallersOnly reverse P/Invoke calls.

Converted call sites

File	Call site	Method
`appdomain.cpp`	`AppDomain::RaiseExitProcessEvent`	`ON_PROCESS_EXIT`
`appdomain.cpp`	`AppDomain::OnUnhandledException`	`ON_UNHANDLED_EXCEPTION`
`assembly.cpp`	`RunManagedStartup`	`MANAGED_STARTUP`
`assembly.cpp`	`RunMainInternal` (TARGET_BROWSER)	`HANDLE_ASYNC_ENTRYPOINT`
`invokeutil.cpp`	`InvokeUtil::CreateClassLoadExcept`	`ReflectionTypeLoadException` ctor
`invokeutil.cpp`	`InvokeUtil::CreateTargetExcept`	`TargetInvocationException` ctor

Remaining priority 3 items (follow ups)

Main entry point in RunMainInternal (dynamic MethodDesc)
CustomAttribute_CreateCustomAttributeInstance (dynamic ctor, already a QCall)
CorHost2::ExecuteAssembly (dynamic method lookup)
FuncEvalWrapper/DoNormalFuncEval (debugger func-eval)

Pattern

Follows the same conversion pattern as #124834 (priority 2). Each conversion adds an [UnmanagedCallersOnly] managed wrapper with an Exception* out-parameter and replaces the native MethodDescCallSite + ARG_SLOT with
UnmanagedCallersOnlyCaller::InvokeThrowing.

Replace MethodDescCallSite/CallDescrWorker calls with more efficient UnmanagedCallersOnly reverse P/Invoke calls for priority 3 items from dotnet#123864. Converted call sites: - AppDomain::RaiseExitProcessEvent (ON_PROCESS_EXIT) - AppDomain::OnUnhandledException (ON_UNHANDLED_EXCEPTION) - RunManagedStartup (MANAGED_STARTUP) - RunMainInternal async helpers (HANDLE_ASYNC_ENTRYPOINT, TARGET_BROWSER) - InvokeUtil::CreateClassLoadExcept (ReflectionTypeLoadException ctor) - InvokeUtil::CreateTargetExcept (TargetInvocationException ctor) Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

dotnet-policy-service · 2026-02-25T12:49:46Z

Tagging subscribers to this area: @agocke
See info in area-owners.md if you want to be subscribed.

src/coreclr/vm/invokeutil.cpp

...libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/AsyncHelpers.Browser.cs

src/coreclr/System.Private.CoreLib/src/System/AppContext.CoreCLR.cs

…-param and managed GetDefinedTypes() throws ReflectionTypeLoadException. Deleted reateClassLoadExcept + UCO wrapper + metasig as a result. Adjusted OnUnhandledException in AppContext.CoreCLR.cs to use a bare catch based on feedback.

Copilot

Pull request overview

This PR converts priority 3 MethodDescCallSite/CallDescrWorker calls to more efficient UnmanagedCallersOnly reverse P/Invoke calls, following the established pattern from PR #124834. The conversions target application entry points and process lifecycle events in CoreCLR.

Changes:

Adds [UnmanagedCallersOnly] wrappers in managed code with Exception* out-parameters for exception propagation
Replaces native MethodDescCallSite calls with UnmanagedCallersOnlyCaller::InvokeThrowing template class
Refactors ReflectionTypeLoadException creation from native to managed code via QCall pattern

Reviewed changes

Copilot reviewed 15 out of 15 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/AsyncHelpers.Browser.cs	Adds UCO wrapper for `HandleAsyncEntryPoint` to handle async Main entry points on Browser target
src/coreclr/System.Private.CoreLib/src/System/StartupHookProvider.CoreCLR.cs	Adds UCO wrapper for `ManagedStartup` with exception handling
src/coreclr/System.Private.CoreLib/src/System/Exception.CoreCLR.cs	Adds UCO wrapper for `CreateTargetInvocationException`
src/coreclr/System.Private.CoreLib/src/System/AppContext.CoreCLR.cs	New file with UCO wrappers for `OnProcessExit` and `OnUnhandledException`
src/coreclr/System.Private.CoreLib/src/System/Reflection/RuntimeModule.cs	Updates `GetTypes` QCall to return exceptions array for managed-side exception construction
src/coreclr/System.Private.CoreLib/System.Private.CoreLib.csproj	Adds new AppContext.CoreCLR.cs file to build
src/coreclr/vm/metasig.h	Adds new metasig definitions for UCO method signatures
src/coreclr/vm/corelib.h	Updates DEFINE_METHOD entries to reference new UCO signatures
src/coreclr/vm/appdomain.cpp	Replaces MethodDescCallSite with UnmanagedCallersOnlyCaller for process lifecycle events
src/coreclr/vm/assembly.cpp	Replaces MethodDescCallSite with UnmanagedCallersOnlyCaller for startup hooks and async entry points
src/coreclr/vm/invokeutil.h	Removes obsolete `CreateClassLoadExcept` declaration
src/coreclr/vm/invokeutil.cpp	Removes `CreateClassLoadExcept` implementation; converts `CreateTargetExcept` to use UCO pattern
src/coreclr/vm/commodule.h	Adds `retExceptions` parameter to `RuntimeModule_GetTypes` QCall signature
src/coreclr/vm/commodule.cpp	Returns exceptions array via out-parameter instead of throwing from native code
src/coreclr/vm/exceptionhandlingqcalls.h	Formatting fix - adds blank line at end of file

src/coreclr/System.Private.CoreLib/src/System/AppContext.CoreCLR.cs

Copilot

Pull request overview

Copilot reviewed 14 out of 14 changed files in this pull request and generated 1 comment.

Comments suppressed due to low confidence (1)

src/coreclr/vm/commodule.cpp:766

RuntimeModule_GetTypes no longer throws inside the QCall when type loading fails, but the loop still doesn’t advance curPos on failure. With retExceptions.Set(...) replacing the throw, execution now continues and will hit _ASSERTE(curPos == dwNumTypeDefs) when any type load fails. Adjust the loop to keep curPos in sync with dwNumTypeDefs (e.g., advance and leave a null slot for failed loads, or remove/replace the assertion and ensure the returned Types array matches the intended semantics).

    // Return exceptions to managed side for throwing
    if (cXcept > 0) {

        gc.xceptRet = (PTRARRAYREF) AllocateObjectArray(cXcept,g_pExceptionClass);
        for (DWORD i=0;i<cXcept;i++) {
            gc.xceptRet->SetAt(i, gc.xcept->GetAt(i));
        }
        retExceptions.Set(gc.xceptRet);
    }

    // We should have filled the array exactly.
    _ASSERTE(curPos == dwNumTypeDefs);

src/coreclr/System.Private.CoreLib/src/System/AppContext.CoreCLR.cs

src/coreclr/vm/invokeutil.cpp

jkotas · 2026-02-27T03:34:20Z

Test failure

ASSERT FAILED
	Expression: curPos == dwNumTypeDefs
	Location:   /__w/1/s/src/coreclr/vm/commodule.cpp:765
	Function:   RuntimeModule_GetTypes
	Process:    84956

src/coreclr/vm/commodule.cpp

jkotas · 2026-02-27T03:45:46Z

The wasm temporary callhelpers needs to be regenerated as part of these PRs: https://github.com/dotnet/runtime/blob/main/docs/workflow/wasm-documentation.md#running-coreclr-callhelpers-generator

Copilot

Pull request overview

Copilot reviewed 14 out of 14 changed files in this pull request and generated 2 comments.

src/coreclr/vm/commodule.cpp

src/coreclr/vm/appdomain.cpp

src/coreclr/vm/commodule.cpp

jkotas · 2026-02-27T15:40:56Z

src/coreclr/vm/wasm/callhelpers-pinvoke.cpp

    {"libSystem.Globalization.Native", s_libSystem_Globalization_Native, 33},
    {"libSystem.IO.Compression.Native", s_libSystem_IO_Compression_Native, 8},
-    {"libSystem.Native", s_libSystem_Native, 97},
+    {"libSystem.Native", s_libSystem_Native, 88},


I am not sure what happened that this number is going down. This PR should not be changing this file.

I was curious of that too. Problem with the script or am I the first to run it on linux?

@radekdoulik @AaronRobinsonMSFT Have you seen this?

Yes. There is some reliability issue with the generator. I've no clue why it goes down. I saw it on Windows and then moved to macOS because I was suspicious of it. I was going to try and find some time to investigate, unclear if I'll find that time. Running on Windows has been painful from a consistency/reliability perspective.

I'm going to coordinate with @radekdoulik and see what needs to happen. I'll run the regeneration once I have a better idea.

Copilot

Pull request overview

Copilot reviewed 16 out of 16 changed files in this pull request and generated 3 comments.

src/coreclr/vm/commodule.cpp

src/coreclr/System.Private.CoreLib/src/System/AppContext.CoreCLR.cs

src/coreclr/vm/wasm/callhelpers-pinvoke.cpp

src/coreclr/vm/commodule.cpp

Copilot

Pull request overview

Copilot reviewed 16 out of 16 changed files in this pull request and generated no new comments.

The generated output included incorrect removals of System.Net.Primitives networking functions and accumulated drift from main. Will regenerate properly in a follow-up with a complete browser build. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

jkotas · 2026-02-27T17:24:54Z

src/coreclr/vm/wasm/entrypoints.h

 #include <string.h>

 #ifdef TARGET_BROWSER
-extern "C" void SystemJS_MarkAsyncMain();


Intentional change?

jkotas

Thanks!

steveisok requested review from AaronRobinsonMSFT and Copilot and removed request for Copilot February 25, 2026 12:48

github-actions bot added the area-VM-coreclr label Feb 25, 2026

dotnet-policy-service bot assigned steveisok Feb 25, 2026

Copilot started reviewing on behalf of steveisok February 25, 2026 12:49 View session

jkotas reviewed Feb 25, 2026

View reviewed changes

build-analysis bot mentioned this pull request Feb 25, 2026

[android][clr] No peer certificates when executing System.Net.Http.Functional.Tests on Android emulator #124526

Open

Copilot AI review requested due to automatic review settings February 25, 2026 16:49

Copilot started reviewing on behalf of steveisok February 25, 2026 16:50 View session

Copilot AI reviewed Feb 25, 2026

View reviewed changes

src/coreclr/System.Private.CoreLib/src/System/AppContext.CoreCLR.cs Outdated Show resolved Hide resolved

steveisok added 2 commits February 25, 2026 13:18

Revert wasm AsyncHelpers change. Will do it in a follow up

23d7f65

Cosmetic review change

cff7a74

Copilot AI review requested due to automatic review settings February 25, 2026 18:50

Copilot started reviewing on behalf of steveisok February 25, 2026 18:51 View session

Copilot AI reviewed Feb 25, 2026

View reviewed changes

src/coreclr/System.Private.CoreLib/src/System/AppContext.CoreCLR.cs Outdated Show resolved Hide resolved

AaronRobinsonMSFT reviewed Feb 25, 2026

View reviewed changes

src/coreclr/System.Private.CoreLib/src/System/AppContext.CoreCLR.cs Outdated Show resolved Hide resolved

AaronRobinsonMSFT reviewed Feb 25, 2026

View reviewed changes

src/coreclr/vm/invokeutil.cpp Outdated Show resolved Hide resolved

AaronRobinsonMSFT reviewed Feb 25, 2026

View reviewed changes

src/coreclr/vm/invokeutil.cpp Show resolved Hide resolved

build-analysis bot mentioned this pull request Feb 25, 2026

Test failure: baseservices/exceptions/stackoverflow/stackoverflowtester/stackoverflowtester.cmd #110173

Open

PR feedback

65aa129

jkotas reviewed Feb 27, 2026

View reviewed changes

src/coreclr/vm/commodule.cpp Show resolved Hide resolved

Copilot AI reviewed Feb 27, 2026

View reviewed changes

src/coreclr/vm/commodule.cpp Show resolved Hide resolved

src/coreclr/vm/appdomain.cpp Show resolved Hide resolved

steveisok added 2 commits February 27, 2026 09:22

Else block for assert

5c93ad2

PR Feedback

9cee755

jkotas reviewed Feb 27, 2026

View reviewed changes

src/coreclr/vm/commodule.cpp Show resolved Hide resolved

src/coreclr/vm/commodule.cpp Show resolved Hide resolved

Apply suggestions from code review

d1814ff

Copilot AI review requested due to automatic review settings February 27, 2026 15:36

jkotas reviewed Feb 27, 2026

View reviewed changes

src/coreclr/vm/commodule.cpp Show resolved Hide resolved

Update src/coreclr/vm/commodule.cpp

41e3a13

jkotas reviewed Feb 27, 2026

View reviewed changes

src/coreclr/vm/commodule.cpp Show resolved Hide resolved

Update src/coreclr/vm/commodule.cpp

0e6a0a8

Copilot started reviewing on behalf of jkotas February 27, 2026 15:36 View session

jkotas reviewed Feb 27, 2026

View reviewed changes

src/coreclr/vm/commodule.cpp Outdated Show resolved Hide resolved

Update src/coreclr/vm/commodule.cpp

ac51b20

jkotas reviewed Feb 27, 2026

View reviewed changes

Copilot AI reviewed Feb 27, 2026

View reviewed changes

src/coreclr/vm/commodule.cpp Outdated Show resolved Hide resolved

src/coreclr/System.Private.CoreLib/src/System/AppContext.CoreCLR.cs Show resolved Hide resolved

src/coreclr/vm/wasm/callhelpers-pinvoke.cpp Outdated Show resolved Hide resolved

jkotas reviewed Feb 27, 2026

View reviewed changes

src/coreclr/vm/commodule.cpp Show resolved Hide resolved

Update src/coreclr/vm/commodule.cpp

24e8cfb

Copilot AI review requested due to automatic review settings February 27, 2026 15:45

jkotas reviewed Feb 27, 2026

View reviewed changes

src/coreclr/vm/commodule.cpp Outdated Show resolved Hide resolved

Apply suggestions from code review

149d633

Copilot started reviewing on behalf of jkotas February 27, 2026 15:46 View session

Copilot AI reviewed Feb 27, 2026

View reviewed changes

steveisok and others added 2 commits February 27, 2026 11:16

Merge remote-tracking branch 'upstream/main' into uco-excep-p3

fe459da

jkotas reviewed Feb 27, 2026

View reviewed changes

jkotas approved these changes Feb 27, 2026

View reviewed changes

Conversation

steveisok commented Feb 25, 2026

Converted call sites

Remaining priority 3 items (follow ups)

Pattern

Uh oh!

dotnet-policy-service bot commented Feb 25, 2026

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

jkotas commented Feb 27, 2026

Uh oh!

Uh oh!

jkotas commented Feb 27, 2026

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

jkotas Feb 27, 2026

Choose a reason for hiding this comment

Uh oh!

steveisok Feb 27, 2026

Choose a reason for hiding this comment

Uh oh!

jkotas Feb 27, 2026

Choose a reason for hiding this comment

Uh oh!

AaronRobinsonMSFT Feb 27, 2026

Choose a reason for hiding this comment

Uh oh!

steveisok Feb 27, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

jkotas Feb 27, 2026

Choose a reason for hiding this comment

Uh oh!

jkotas left a comment

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone