https://github.com/keinflue created https://github.com/llvm/llvm-project/pull/175833
Commit 543f112e148a enabled diagnostics for C++ compatibility for jumps over initialization of variables. However, inadvertently this may cause a prior diagnostic for jumps into scopes of variables with variably modified types to be replaced with the less severe C++ compatibility warning, resulting in impossible codegen. This skips the check for the C++ compatibility warning if there is already another diagnostic planned for the scope. Fixes #175540 >From eb30f1fc2093d86a74b2557854ac7226462262ae Mon Sep 17 00:00:00 2001 From: keinflue <[email protected]> Date: Tue, 13 Jan 2026 21:38:05 +0100 Subject: [PATCH] [clang] Restore diagnostic for certain jumps into VLA(ish) scopes. Commit 543f112e148a enabled diagnostics for C++ compatibility for jumps over initialization of variables. However, inadvertently this may cause a prior diagnostic for jumps into scopes of variables with variably modified types to be replaced with the less severe C++ compatibility warning, resulting in impossible codegen. This skips the check for the C++ compatibility warning if there is already another diagnostic planned for the scope. Fixes #175540 --- clang/docs/ReleaseNotes.rst | 2 ++ clang/lib/Sema/JumpDiagnostics.cpp | 4 +++- clang/test/Sema/scope-check.c | 8 ++++++++ 3 files changed, 13 insertions(+), 1 deletion(-) diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 85d2e562d1ecd..b91d99647855c 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -133,6 +133,8 @@ Miscellaneous Bug Fixes Miscellaneous Clang Crashes Fixed ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +- Fixed a crash when attempting to jump over initialization of a variable with variably modified type. (#GH175540) + OpenACC Specific Changes ------------------------ diff --git a/clang/lib/Sema/JumpDiagnostics.cpp b/clang/lib/Sema/JumpDiagnostics.cpp index 36c9d9afb37f1..2c45de69e7cdf 100644 --- a/clang/lib/Sema/JumpDiagnostics.cpp +++ b/clang/lib/Sema/JumpDiagnostics.cpp @@ -179,8 +179,10 @@ static ScopePair GetDiagForGotoScopeDecl(Sema &S, const Decl *D) { } } + // An earlier diag::note_protected_by_vla is more severe, so don't overwrite + // it here. if (const Expr *Init = VD->getInit(); - VD->hasLocalStorage() && Init && !Init->containsErrors()) { + !InDiag && VD->hasLocalStorage() && Init && !Init->containsErrors()) { // C++11 [stmt.dcl]p3: // A program that jumps from a point where a variable with automatic // storage duration is not in scope to a point where it is in scope diff --git a/clang/test/Sema/scope-check.c b/clang/test/Sema/scope-check.c index c6aa421b3ebde..f0100759ca9b2 100644 --- a/clang/test/Sema/scope-check.c +++ b/clang/test/Sema/scope-check.c @@ -256,3 +256,11 @@ void GH63682() { (void)({P:1;}); // expected-note {{jump enters a statement expression}} } } + +void gh175549(int b, void* c) { + __asm__ goto("" : : : : d); // expected-error {{cannot jump from this asm goto statement to one of its possible targets}} + int(*a)[b] = c; // expected-note {{jump bypasses initialization of variable length array}} +d: // expected-note {{possible target of asm goto statement}} + (void)a[0]; +} + _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
