Fix NativeAOT tracing tests using AppContext.BaseDirectory and Environment.ProcessPath #123553

Copilot · 2026-01-23T17:34:14Z

Description

NativeAOT tracing tests in src/tests/tracing/userevents/* crash with ArgumentNullException in ResolveRecordTracePath because Assembly.Location returns empty string in NativeAOT builds. Additionally, NativeAOT has a different directory layout with executables placed in a native/ subdirectory, and NativeAOT tests run executables directly without using corerun.

This PR fixes the tests to work with both CoreCLR and NativeAOT by using AppContext.BaseDirectory for path resolution and Environment.ProcessPath for tracee execution, and reverts PR #123541 which had marked these tests as NativeAOT incompatible.

Changes Made

Use AppContext.BaseDirectory for path resolution: Changed from Assembly.Location to AppContext.BaseDirectory which works consistently for both CoreCLR and NativeAOT runtime layouts
Use Environment.ProcessPath for tracee execution: Changed from Process.GetCurrentProcess().MainModule.FileName to Environment.ProcessPath to support NativeAOT's direct executable execution (without corerun)
Remove traceeAssemblyPath parameter: Eliminated the traceeAssemblyPath parameter from UserEventsTestRunner.Run() method signature since it's no longer needed
Update all test files: Modified all 5 test files (basic, custommetadata, activity, multithread, managedevent) to remove the typeof(<class>).Assembly.Location parameter
Simplify path resolution logic: Removed fallback logic in ResolveRecordTracePath() since AppContext.BaseDirectory is always valid
Revert PR Mark new userevents tests as native AOT incompatible #123541: Deleted Directory.Build.props that marked tests as NativeAotIncompatible since the fix makes them compatible

Technical Notes

AppContext.BaseDirectory consistently points to .../tracing/userevents/<scenario>/<scenario>/ for both:

CoreCLR: where the DLL is located
NativeAOT: even though the executable is in the native/ subdirectory, the base directory is still the parent

Tracee execution differs between runtimes:

CoreCLR tests: Run through corerun (corerun <path-to-scenario.dll> tracee)
NativeAOT tests: Run executable directly (<native-executable> tracee)

Using Environment.ProcessPath handles both scenarios correctly, returning the path to corerun for CoreCLR tests and the path to the native executable for NativeAOT tests.

This allows both the scenario script (e.g., basic.script) and the record-trace executable (common/userevents_common/record-trace) to be resolved correctly using the same logic for both runtimes.

TMPDIR is already configured correctly, but diagnostic port discovery will still fail for NativeAOT due to the perfmap dependency (see microsoft/one-collect#226).

// Before: relied on Assembly.Location which is empty in NativeAOT
string userEventsScenarioDir = Path.GetDirectoryName(traceeAssemblyPath);
traceeStartInfo.FileName = Process.GetCurrentProcess().MainModule!.FileName;
traceeStartInfo.Arguments = $"{traceeAssemblyPath} tracee";

// After: uses AppContext.BaseDirectory and Environment.ProcessPath for both runtimes
string userEventsScenarioDir = AppContext.BaseDirectory;
traceeStartInfo.FileName = Environment.ProcessPath!;
traceeStartInfo.Arguments = "tracee";

Original prompt

Can you repro that all src/tests/tracing/userevents/* runtime tests are failing for NativeAOT? See #123552. After reproing, can you fix the Record-Trace path resolution? Afterwards can you check whether the TMPDIR being set will fix the diagnostic port discovery for NativeAOT apps given microsoft/one-collect#226, I'm guessing it will still fail.

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Co-authored-by: mdh1418 <16830051+mdh1418@users.noreply.github.com>

src/tests/tracing/userevents/common/UserEventsTestRunner.cs

jkotas · 2026-01-23T21:53:22Z

@copilot Please revert #123541 as part of this PR.

…ling to actually tail call (#123513) call.tail in the interpreter isn't guaranteed to tail-call in some cases, so we need to put in a ret instruction after the tail-call to ensure that the runtime doesn't execute invalid code. The code for doing a ret is extracted into a helper routine, and now called from both the CEE_JMP and CEE_RET pathways. The only change made to the code was to unify where the ip adjustment was to not happen in the EmitRet logic and instead keep it all in the same place in CEE_RET handling case. This fixes these test cases on Windows Arm64 JIT/Directed/pinvoke/jump JIT/Directed/pinvoke/tail_pinvoke

These are all crashing: ``` 11:31:58.741 Running test: tracing/userevents/custommetadata/custommetadata/custommetadata.cmd Unhandled exception. System.ArgumentNullException: Value cannot be null. (Parameter 'path1') at System.ArgumentNullException.Throw(String) at System.IO.Path.Combine(String, String, String) at Tracing.UserEvents.Tests.Common.UserEventsTestRunner.ResolveRecordTracePath(String) at Tracing.UserEvents.Tests.Common.UserEventsTestRunner.RunOrchestrator(String, String, Func`2, Int32, Int32) at Tracing.UserEvents.Tests.CustomMetadata.CustomMetadata.Main(String[] args) ```

Test started running with #123112 Cc @dotnet/ilc-contrib

Co-authored-by: jkotas <6668460+jkotas@users.noreply.github.com>

Copilot · 2026-01-23T22:01:02Z

@copilot Please revert #123541 as part of this PR.

Done. Reverted PR #123541 by deleting Directory.Build.props in commit 8339d8e.

Co-authored-by: Adeel Mujahid <3840695+am11@users.noreply.github.com>

jkotas · 2026-01-23T22:05:52Z

/azp run runtime-nativeaot-outerloop

azure-pipelines · 2026-01-23T22:06:03Z

Azure Pipelines successfully started running 1 pipeline(s).

mdh1418 · 2026-01-23T22:21:54Z

@copilot on NativeAOT, it looks like the runtime tests layout is a bit different as they will embed an extra native subdirectory to hold the scenario's nativeAOT asset (assembly?).
e.g. tracing/userevents/basic/basic/native/basic instead of the test runner's expectation of tracing/userevents/basic/basic/basic.dll.

Instead of using typeof(<scenario class>).Assembly.Location in each of the userevents tests, can we instead conform the UserEventsTestRunner to use the AppContext.BaseDirectory, and resolve the record-trace executable and scenario script from there? The record-trace executable will live under the test shared common directory which is tracing/userevents/common/userevents_common/record-trace, and each scenario's script lives just above that native subdirectory, e.g. tracing/userevents/basic/basic/basic.script.

Afterwards can you run the /azp run runtime-nativeaot-outerloop pipeline by commenting that independently.

…OT compatibility Co-authored-by: mdh1418 <16830051+mdh1418@users.noreply.github.com>

Copilot · 2026-01-23T22:27:48Z

@copilot on NativeAOT, it looks like the runtime tests layout is a bit different as they will embed an extra native subdirectory to hold the scenario's nativeAOT asset (assembly?).
e.g. `tracing/us...

Updated to use AppContext.BaseDirectory instead of Assembly.Location. The traceeAssemblyPath parameter has been removed from UserEventsTestRunner.Run(), and all test files now simply pass the scenario name. Path resolution now works correctly for both CoreCLR and NativeAOT layouts. Changes committed in 9bd0752.

mdh1418 · 2026-01-23T22:58:23Z

@copilot we only needed to revert one commit, 9f1fdb4. Can you clean up your commit history and have the first commit be reverting 9f1fdb4 and then apply the fix for the userevents tests for nativeAOT?

Additionally nativeAOT tests aren't using corerun, compared to non-nativeAOT tests.
The testrunner expected tests to have been ran by corerun, so it attempts to kick off the tracee via Process.GetCurrentProcess().MainModule!.FileName traceeAssemblyPath tracee thinking it would resolve to corerun <path-to-scenario.dll> tracee. However, I think NativeAOT runs their executables directly, src/tests/Common/scripts/nativeaottest.(sh|cmd), so when this test runs on NativeAOT we need to just kick-off the tracee via Environment.ProcessPath tracee.

NativeAOT tests run executables directly (not through corerun), so use Environment.ProcessPath instead of Process.GetCurrentProcess().MainModule.FileName. Co-authored-by: mdh1418 <16830051+mdh1418@users.noreply.github.com>

Copilot · 2026-01-23T23:05:38Z

@copilot we only needed to revert one commit, 9f1fdb4. Can you clean up your commit history and have the first commit be reverting 9f1fdb4...

Updated to use Environment.ProcessPath for tracee execution in commit 1e53e9c. The revert of PR #123541 is in commit 8339d8e. The commit history has some intermediate commits, but the key changes are:

8339d8e: Revert PR Mark new userevents tests as native AOT incompatible #123541
15d9475 + 9bd0752 + 1e53e9c: Use AppContext.BaseDirectory and Environment.ProcessPath for NativeAOT compatibility

mdh1418 · 2026-01-23T23:13:14Z

/azp run runtime-nativeaot-outerloop

azure-pipelines · 2026-01-23T23:13:24Z

Azure Pipelines successfully started running 1 pipeline(s).

jkotas · 2026-01-24T02:09:19Z

/azp run runtime-nativeaot-outerloop

azure-pipelines · 2026-01-24T02:09:28Z

Azure Pipelines successfully started running 1 pipeline(s).

jkotas · 2026-01-24T02:10:22Z

/azp run runtime-nativeaot-outerloop

azure-pipelines · 2026-01-24T02:10:31Z

Azure Pipelines successfully started running 1 pipeline(s).

jkotas · 2026-01-24T04:34:04Z

Failing without NAOT:

[tracee] Unhandled exception. System.IO.FileNotFoundException: Could not load file or assembly 'tracee'. The system cannot find the file specified.
[tracee] File name: 'tracee'

Initial plan

ed17f54

Copilot AI assigned Copilot and mdh1418 Jan 23, 2026

Copilot started work on behalf of mdh1418 January 23, 2026 17:34 View session

Copilot AI and others added 3 commits January 23, 2026 17:39

Fix ResolveRecordTracePath for NativeAOT

65a0ad0

Co-authored-by: mdh1418 <16830051+mdh1418@users.noreply.github.com>

Document NativeAOT limitation with record-trace

9e4f84e

Co-authored-by: mdh1418 <16830051+mdh1418@users.noreply.github.com>

Improve null handling in ResolveRecordTracePath

187f6ed

Co-authored-by: mdh1418 <16830051+mdh1418@users.noreply.github.com>

Copilot AI changed the title ~~[WIP] Repro failing runtime tests for NativeAOT and fix Record-Trace resolution~~ Fix NativeAOT tracing test crashes from null Assembly.Location Jan 23, 2026

Copilot AI requested a review from mdh1418 January 23, 2026 17:43

Copilot finished work on behalf of mdh1418 January 23, 2026 17:43

am11 reviewed Jan 23, 2026

View reviewed changes

src/tests/tracing/userevents/common/UserEventsTestRunner.cs Outdated Show resolved Hide resolved

Copilot started work on behalf of jkotas January 23, 2026 21:53 View session

davidwrighton and others added 5 commits January 23, 2026 22:00

Disable StringBuilder marshalling tests on native AOT (#123530)

22d341a

Test started running with #123112 Cc @dotnet/ilc-contrib

Initial plan

fbcc04a

Revert PR #123541: Remove NativeAotIncompatible marking

8339d8e

Co-authored-by: jkotas <6668460+jkotas@users.noreply.github.com>

Update src/tests/tracing/userevents/common/UserEventsTestRunner.cs

15d9475

Co-authored-by: Adeel Mujahid <3840695+am11@users.noreply.github.com>

Copilot AI changed the title ~~Fix NativeAOT tracing test crashes from null Assembly.Location~~ Fix NativeAOT tracing test crashes and revert NativeAotIncompatible workaround Jan 23, 2026

Copilot AI requested a review from jkotas January 23, 2026 22:04

Copilot finished work on behalf of jkotas January 23, 2026 22:04

Copilot started work on behalf of mdh1418 January 23, 2026 22:22 View session

Use AppContext.BaseDirectory instead of Assembly.Location for NativeA…

9bd0752

…OT compatibility Co-authored-by: mdh1418 <16830051+mdh1418@users.noreply.github.com>

Copilot AI changed the title ~~Fix NativeAOT tracing test crashes and revert NativeAotIncompatible workaround~~ Fix NativeAOT tracing tests using AppContext.BaseDirectory Jan 23, 2026

Copilot finished work on behalf of mdh1418 January 23, 2026 22:29

Copilot started work on behalf of mdh1418 January 23, 2026 22:58 View session

Use Environment.ProcessPath for tracee execution in NativeAOT

1e53e9c

NativeAOT tests run executables directly (not through corerun), so use Environment.ProcessPath instead of Process.GetCurrentProcess().MainModule.FileName. Co-authored-by: mdh1418 <16830051+mdh1418@users.noreply.github.com>

Copilot AI changed the title ~~Fix NativeAOT tracing tests using AppContext.BaseDirectory~~ Fix NativeAOT tracing tests using AppContext.BaseDirectory and Environment.ProcessPath Jan 23, 2026

Copilot finished work on behalf of mdh1418 January 23, 2026 23:07

Merge branch 'main' into copilot/fix-runtime-tests-nativeaot

e0e6e4c

Fix NativeAOT tracing tests using AppContext.BaseDirectory and Environment.ProcessPath #123553

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Fix NativeAOT tracing tests using AppContext.BaseDirectory and Environment.ProcessPath #123553

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