llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang-codegen Author: None (AV01DANC3) <details> <summary>Changes</summary> When a VLA type is hidden behind a type alias and used as a local variable inside a local class or struct constructor, CodeGen could fail to emit VLA size information, leading to an assertion failure in getVLASize(). Desugar the variable type before emitting variably-modified type information. Add a regression test. --- Full diff: https://github.com/llvm/llvm-project/pull/183933.diff 2 Files Affected: - (modified) clang/lib/CodeGen/CGDecl.cpp (+4-2) - (added) clang/test/CodeGenCXX/vla-alias-local-struct.cpp (+15) ``````````diff diff --git a/clang/lib/CodeGen/CGDecl.cpp b/clang/lib/CodeGen/CGDecl.cpp index 8b5ffde1b73f3..a08e0a79671d1 100644 --- a/clang/lib/CodeGen/CGDecl.cpp +++ b/clang/lib/CodeGen/CGDecl.cpp @@ -1493,8 +1493,10 @@ CodeGenFunction::EmitAutoVarAlloca(const VarDecl &D) { CharUnits alignment = getContext().getDeclAlign(&D); // If the type is variably-modified, emit all the VLA sizes for it. - if (Ty->isVariablyModifiedType()) - EmitVariablyModifiedType(Ty); + if (Ty->isVariablyModifiedType()) { + QualType DesugaredTy = Ty.getDesugaredType(getContext()); + EmitVariablyModifiedType(DesugaredTy); + } auto *DI = getDebugInfo(); bool EmitDebugInfo = DI && CGM.getCodeGenOpts().hasReducedDebugInfo(); diff --git a/clang/test/CodeGenCXX/vla-alias-local-struct.cpp b/clang/test/CodeGenCXX/vla-alias-local-struct.cpp new file mode 100644 index 0000000000000..bb33bdbcccb87 --- /dev/null +++ b/clang/test/CodeGenCXX/vla-alias-local-struct.cpp @@ -0,0 +1,15 @@ +// RUN: %clang_cc1 -std=gnu++20 -emit-llvm %s -o - >/dev/null + +int f() { return 1; } + +int test0() { + using X = int[f()]; + + struct S { + S() { + X x; + } + } s; + + return 0; +} `````````` </details> https://github.com/llvm/llvm-project/pull/183933 _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
