https://github.com/AZero13 created https://github.com/llvm/llvm-project/pull/218830
The fake-use coroutine check in EmitParmDecl calls FnDecl->getBody()->getStmtClass() without guarding against a null getBody(). This crashes when processing implicit parameters (e.g. should_call_delete) of MSVC deleting destructors whose base destructor is only declared, not defined. >From d1fa49dded08aa29ed019190b506e64e0caf1c88 Mon Sep 17 00:00:00 2001 From: AZero13 <[email protected]> Date: Tue, 25 Aug 2026 23:32:14 -0400 Subject: [PATCH] [Clang][CodeGen] Fix crash in EmitParmDecl for bodyless destructors with -fextend-variable-liveness The fake-use coroutine check in EmitParmDecl calls FnDecl->getBody()->getStmtClass() without guarding against a null getBody(). This crashes when processing implicit parameters (e.g. should_call_delete) of MSVC deleting destructors whose base destructor is only declared, not defined. --- clang/lib/CodeGen/CGDecl.cpp | 2 +- clang/test/CodeGen/fake-use-msvc-dtor.cpp | 17 +++++++++++++++++ 2 files changed, 18 insertions(+), 1 deletion(-) create mode 100644 clang/test/CodeGen/fake-use-msvc-dtor.cpp diff --git a/clang/lib/CodeGen/CGDecl.cpp b/clang/lib/CodeGen/CGDecl.cpp index b8fae352d41d7..1ed8989d3f627 100644 --- a/clang/lib/CodeGen/CGDecl.cpp +++ b/clang/lib/CodeGen/CGDecl.cpp @@ -2856,7 +2856,7 @@ void CodeGenFunction::EmitParmDecl(const VarDecl &D, ParamValue Arg, &D == CXXABIThisDecl)) { // We don't emit fake uses for coroutine parameters, other than `this`. if (auto *FnDecl = dyn_cast_or_null<FunctionDecl>(CurCodeDecl); - &D == CXXABIThisDecl || !FnDecl || + &D == CXXABIThisDecl || !FnDecl || !FnDecl->getBody() || FnDecl->getBody()->getStmtClass() != Stmt::CoroutineBodyStmtClass) { if (shouldExtendLifetime(getContext(), CurCodeDecl, D, CXXABIThisDecl)) EHStack.pushCleanup<FakeUse>(NormalFakeUse, DeclPtr); diff --git a/clang/test/CodeGen/fake-use-msvc-dtor.cpp b/clang/test/CodeGen/fake-use-msvc-dtor.cpp new file mode 100644 index 0000000000000..3988b4b2242ec --- /dev/null +++ b/clang/test/CodeGen/fake-use-msvc-dtor.cpp @@ -0,0 +1,17 @@ +// RUN: %clang_cc1 %s -triple x86_64-pc-windows-msvc -emit-llvm -fextend-variable-liveness=all -O1 -mconstructor-aliases -o /dev/null +// Verify that we do not crash when generating fake uses for parameters +// of destructor declarations that have no body (the should_call_delete +// implicit parameter in MSVC deleting destructors). + +struct A { + virtual ~A(void); +}; +struct B { + virtual ~B(void); +}; + +struct C : A, B {}; + +void foo() { + C c; +} _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
