[CIR][NFC] Fix memory corruption in type converter

[andykaylor]

This fixes a problem where a rogue call to converter.addConversion inside of a type conversion lambda was causing memory corruption that (luckily!) triggered a test failure on some build platforms.

Near as I can tell, the unwanted addConversion call was the result of a bad rebase (by me). The code shouldn't have ever been there. Because the failure depends on the build environment, I can't find a reliable way to test this change.

[llvmbot]

@llvm/pr-subscribers-clang

@llvm/pr-subscribers-clangir

Author: Andy Kaylor (andykaylor)

Changes

This fixes a problem where a rogue call to converter.addConversion inside of a type conversion lambda was causing memory corruption that (luckily!) triggered a test failure on some build platforms.

Near as I can tell, the unwanted addConversion call was the result of a bad rebase (by me). The code shouldn't have ever been there. Because the failure depends on the build environment, I can't find a reliable way to test this change.

---

Full diff: https://github.com/llvm/llvm-project/pull/160211.diff

1 Files Affected:

• (modified) clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp (-3)

diff --git a/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp b/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp
index 1865698838134..1596ccb6a2617 100644
--- a/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp
+++ b/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp
@@ -2381,9 +2381,6 @@ static void prepareTypeConverter(mlir::LLVMTypeConverter &converter,
       }
       break;
     }
-    converter.addConversion([&](cir::VoidType type) -> mlir::Type {
-      return mlir::LLVM::LLVMVoidType::get(type.getContext());
-    });
 
     // Record has a name: lower as an identified record.
     mlir::LLVM::LLVMStructType llvmStruct;

[razvanlupusoru]

Thank you for fixing this!

[bcardosolopes]

Thanks!

[llvm-ci]

LLVM Buildbot has detected a new failure on builder ppc64le-flang-rhel-clang running on ppc64le-flang-rhel-test while building clang at step 6 "test-build-unified-tree-check-flang".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/157/builds/40137

Here is the relevant piece of the build log for the reference

Step 6 (test-build-unified-tree-check-flang) failure: 1200 seconds without output running [b'ninja', b'check-flang'], attempting to kill
...
PASS: Flang :: Transforms/DoConcurrent/skip_all_nested_loops.f90 (3828 of 3839)
PASS: Flang :: Transforms/debug-omp-target-op-1.fir (3829 of 3839)
PASS: Flang :: Transforms/verify-known-runtime-functions.fir (3830 of 3839)
PASS: Flang :: Driver/linker-flags.f90 (3831 of 3839)
PASS: Flang :: Transforms/tbaa3.fir (3832 of 3839)
PASS: Flang :: Transforms/tbaa-local-alloc-threshold.fir (3833 of 3839)
PASS: Flang :: Transforms/stack-arrays.f90 (3834 of 3839)
PASS: Flang :: Transforms/debug-dwarf-version.fir (3835 of 3839)
PASS: Flang :: Driver/omp-driver-offload.f90 (3836 of 3839)
PASS: Flang :: Driver/fopenmp.f90 (3837 of 3839)
command timed out: 1200 seconds without output running [b'ninja', b'check-flang'], attempting to kill
process killed by signal 9
program finished with exit code -1
elapsedTime=2325.713352