Replace string comparison with AST check in IsBuiltin for std::complex by tryh4rd-26 · Pull Request #842 · compiler-research/CppInterOp

tryh4rd-26 · 2026-03-07T12:15:57Z

Description

Replace the fragile string-based check for std::complex in IsBuiltin() with a proper Clang AST query.

he old code was checking if a type's name contained the word "complex" as a string, which is pretty hacky cuz any random user class with "complex" in the name would get wrongly treated as a builtin. I swapped it out for a proper AST check that looks at whether the type is actually a std::complex<T>specialization by walking the Clang AST. Same approach that's already used in other parts of the codebase, so it fits right in.

Resolves the FIXME at line 411: // FIXME: Figure out how to avoid the string comparison.

Type of change

Bug fix
New feature
Requires documentation updates

Testing

Ran the existing ScopeReflection_IsBuiltin test which covers:
- Builtin types (bool, char, signed char, void)
- C _Complex types (_Complex float, _Complex double, _Complex long double, _Complex __float128)
- std::complex<T> template specializations (via #include <complex> and iterating over specializations)
Full test suite: 100% tests passed, 0 tests failed out of 3

$ CppInterOpTests --gtest_filter="*IsBuiltin*"
[ RUN      ] CppInterOpTest/InProcessJIT.ScopeReflection_IsBuiltin
[       OK ] CppInterOpTest/InProcessJIT.ScopeReflection_IsBuiltin (290 ms)
[  PASSED  ] 1 test.

Checklist

I have read the contribution guide recently

codecov · 2026-03-07T12:28:38Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 79.75%. Comparing base (4e3e4c2) to head (af15f8b).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #842      +/-   ##
==========================================
+ Coverage   79.72%   79.75%   +0.03%     
==========================================
  Files          11       11              
  Lines        4025     4031       +6     
==========================================
+ Hits         3209     3215       +6     
  Misses        816      816

Files with missing lines	Coverage Δ
lib/CppInterOp/CppInterOp.cpp	`87.98% <100.00%> (+0.03%)`	⬆️

Files with missing lines	Coverage Δ
lib/CppInterOp/CppInterOp.cpp	`87.98% <100.00%> (+0.03%)`	⬆️

🚀 New features to boost your workflow:

❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

github-actions · 2026-03-07T12:29:10Z

clang-tidy review says "All clean, LGTM! 👍"

Vipul-Cariappa

Looks good to me!
Could you add a test case that covers the uncovered line for the test coverage.

Vipul-Cariappa · 2026-03-09T08:18:38Z

lib/CppInterOp/CppInterOp.cpp

+  if (const auto* RD = Ty->getAsCXXRecordDecl()) {
+    if (const auto* CTSD = dyn_cast<ClassTemplateSpecializationDecl>(RD)) {
+      IdentifierInfo* II = CTSD->getSpecializedTemplate()->getIdentifier();
+      if (II && II->isStr("complex") &&


There is still some string comparison, but I guess this is a better approach.

tryh4rd-26 · 2026-03-09T12:23:08Z

Looks good to me! Could you add a test case that covers the uncovered line for the test coverage.

Hi I am Done

github-actions · 2026-03-09T12:36:23Z

clang-tidy review says "All clean, LGTM! 👍"

aaronj0 · 2026-03-09T18:59:57Z

Hi I am Done

Can you rebase on latest main to fix the CI failures? (and squash into a single commit)

tryh4rd-26 · 2026-03-09T19:06:11Z

Can you rebase on latest main to fix the CI failures? (and squash into a single commit)

Yup done!

mcbarton · 2026-03-09T19:32:13Z

Hi I am Done

Can you rebase on latest main to fix the CI failures? (and squash into a single commit)

@aaronj0 Rebasing will not fix the Emscripten ci failures. xeus-cpp not expects xeus 6.0 and above, so you need this PR to go in #845 and then rebase to fix the Emscripten ci.

tryh4rd-26 · 2026-03-09T19:56:27Z

Hi I am Done

Can you rebase on latest main to fix the CI failures? (and squash into a single commit)

@aaronj0 Rebasing will not fix the Emscripten ci failures. xeus-cpp not expects xeus 6.0 and above, so you need this PR to go in #845 and then rebase to fix the Emscripten ci.

Will I do this or will the maintainers?

github-actions · 2026-03-09T20:29:37Z

clang-tidy review says "All clean, LGTM! 👍"

Vipul-Cariappa

LGTM!

I am approving this, but will defer merging for now. As the CI is failing, I believe the CI failures are unrelated to these changes.

Vipul-Cariappa · 2026-03-10T07:59:19Z

Will I do this or will the maintainers?

We are looking into the failures in the CI. For now, I don't think it is caused by your changes, therefore we will take care of it. Unless we find out there is some change in this PR that is the cause. You will have to fix things. Will inform you 😄.

vgvassilev · 2026-03-10T10:06:54Z

lib/CppInterOp/CppInterOp.cpp

+  if (const auto* RD = Ty->getAsCXXRecordDecl()) {
+    if (const auto* CTSD = dyn_cast<ClassTemplateSpecializationDecl>(RD)) {
+      IdentifierInfo* II = CTSD->getSpecializedTemplate()->getIdentifier();
+      if (II && II->isStr("complex") &&


What about Type::isAnyComplexType?

isAnyComplexType() is already called on line 409 ... but std::complex<T> is a class temp record type and , not a Clang ComplexType, so the func should be returning false for it. The AST check below is specifically to handle standard complex typpa specialisations.

tryh4rd-26 · 2026-03-10T11:11:57Z

Will I do this or will the maintainers?

We are looking into the failures in the CI. For now, I don't think it is caused by your changes, therefore we will take care of it. Unless we find out there is some change in this PR that is the cause. You will have to fix things. Will inform you 😄.

Understood thank you!

github-actions · 2026-03-12T14:52:58Z

clang-tidy review says "All clean, LGTM! 👍"

tryh4rd-26 · 2026-03-12T18:18:34Z

Hi @Vipul-Cariappa , I rebased it to the latest fix and seems all CI errors have been resolves

github-actions · 2026-03-12T19:51:39Z

clang-tidy review says "All clean, LGTM! 👍"

tryh4rd-26 force-pushed the fix-isbuiltin-string-comparison branch from 4bfa493 to 0c8daee Compare March 7, 2026 12:20

Vipul-Cariappa requested changes Mar 9, 2026

View reviewed changes

tryh4rd-26 requested a review from Vipul-Cariappa March 9, 2026 12:27

tryh4rd-26 force-pushed the fix-isbuiltin-string-comparison branch from ba65476 to 434eabc Compare March 9, 2026 19:05

Vipul-Cariappa approved these changes Mar 10, 2026

View reviewed changes

vgvassilev reviewed Mar 10, 2026

View reviewed changes

Replace string comparison with AST check in IsBuiltin for std::complex

210eee9

tryh4rd-26 force-pushed the fix-isbuiltin-string-comparison branch from 434eabc to 210eee9 Compare March 12, 2026 14:40

Merge branch 'main' into fix-isbuiltin-string-comparison

af15f8b

Vipul-Cariappa merged commit 9e51622 into compiler-research:main Mar 13, 2026
36 checks passed

tryh4rd-26 deleted the fix-isbuiltin-string-comparison branch March 13, 2026 08:34

Conversation

tryh4rd-26 commented Mar 7, 2026

Description

Type of change

Testing

Checklist

Uh oh!

codecov bot commented Mar 7, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Codecov Report

Uh oh!

github-actions bot commented Mar 7, 2026

Uh oh!

Vipul-Cariappa left a comment

Choose a reason for hiding this comment

Uh oh!

Vipul-Cariappa Mar 9, 2026

Choose a reason for hiding this comment

Uh oh!

tryh4rd-26 commented Mar 9, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

github-actions bot commented Mar 9, 2026

Uh oh!

aaronj0 commented Mar 9, 2026

Uh oh!

tryh4rd-26 commented Mar 9, 2026

Uh oh!

mcbarton commented Mar 9, 2026

Uh oh!

tryh4rd-26 commented Mar 9, 2026

Uh oh!

github-actions bot commented Mar 9, 2026

Uh oh!

Vipul-Cariappa left a comment

Choose a reason for hiding this comment

Uh oh!

Vipul-Cariappa commented Mar 10, 2026

Uh oh!

vgvassilev Mar 10, 2026

Choose a reason for hiding this comment

Uh oh!

tryh4rd-26 Mar 10, 2026

Choose a reason for hiding this comment

Uh oh!

tryh4rd-26 commented Mar 10, 2026

Uh oh!

github-actions bot commented Mar 12, 2026

Uh oh!

tryh4rd-26 commented Mar 12, 2026

Uh oh!

github-actions bot commented Mar 12, 2026

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

5 participants

codecov bot commented Mar 7, 2026 •

edited

Loading

tryh4rd-26 commented Mar 9, 2026 •

edited

Loading