Author: MillePlateaux Date: 2025-04-14T13:10:20-07:00 New Revision: 061f87f75f38e80e7494b5f7235103f7f11a36c3
URL: https://github.com/llvm/llvm-project/commit/061f87f75f38e80e7494b5f7235103f7f11a36c3 DIFF: https://github.com/llvm/llvm-project/commit/061f87f75f38e80e7494b5f7235103f7f11a36c3.diff LOG: [Clang][Sema]:Fix musttail attribute on a function with not_tail_called attribute has no warning/error (#134465) The error is emitted when a musttail call is made to a function marked with the not_tail_called attribute.Closes #133509 Added: clang/test/Sema/attr-musttail.cpp Modified: clang/docs/ReleaseNotes.rst clang/include/clang/Basic/DiagnosticSemaKinds.td clang/lib/Sema/SemaStmt.cpp Removed: ################################################################################ diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 840a52a693c7a..f9ba1bcf542ef 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -356,6 +356,8 @@ Improvements to Clang's diagnostics - Now correctly diagnose a tentative definition of an array with static storage duration in pedantic mode in C. (#GH50661) +- An error is now emitted when a ``musttail`` call is made to a function marked with the ``not_tail_called`` attribute. (#GH133509). + Improvements to Clang's time-trace ---------------------------------- diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td index 180ca39bc07e9..a9ff821d49405 100644 --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -3172,6 +3172,8 @@ def note_musttail_mismatch : Note< "|has type mismatch at %ordinal3 parameter" "% diff { (expected $ but has $)|}1,2" "|has diff erent return type% diff { ($ expected but has $)|}1,2}0">; +def note_musttail_disabled_by_not_tail_called : Note< + "'not_tail_called' attribute prevents being called as a tail call">; def err_musttail_callconv_mismatch : Error< "cannot perform a tail call to function%select{| %1}0 because it uses an " "incompatible calling convention">; diff --git a/clang/lib/Sema/SemaStmt.cpp b/clang/lib/Sema/SemaStmt.cpp index e1b9ccc693bd5..39c2e157591df 100644 --- a/clang/lib/Sema/SemaStmt.cpp +++ b/clang/lib/Sema/SemaStmt.cpp @@ -717,6 +717,13 @@ bool Sema::checkMustTailAttr(const Stmt *St, const Attr &MTA) { return false; } + if (const FunctionDecl *CalleeDecl = CE->getDirectCallee(); + CalleeDecl && CalleeDecl->hasAttr<NotTailCalledAttr>()) { + Diag(St->getBeginLoc(), diag::err_musttail_mismatch) << /*show-function-callee=*/true << CalleeDecl; + Diag(CalleeDecl->getLocation(), diag::note_musttail_disabled_by_not_tail_called); + return false; + } + if (const auto *EWC = dyn_cast<ExprWithCleanups>(E)) { if (EWC->cleanupsHaveSideEffects()) { Diag(St->getBeginLoc(), diag::err_musttail_needs_trivial_args) << &MTA; diff --git a/clang/test/Sema/attr-musttail.cpp b/clang/test/Sema/attr-musttail.cpp new file mode 100644 index 0000000000000..2d0ca937f9b46 --- /dev/null +++ b/clang/test/Sema/attr-musttail.cpp @@ -0,0 +1,17 @@ +// RUN: %clang_cc1 -verify -fsyntax-only %s + +int __attribute__((not_tail_called)) foo1(int a) {// expected-note {{'not_tail_called' attribute prevents being called as a tail call}} + return a + 1; +} + + +int foo2(int a) { + [[clang::musttail]] + return foo1(a); // expected-error {{cannot perform a tail call to function 'foo1' because its signature is incompatible with the calling function}} +} + +int main() { + int result = foo2(10); + return 0; +} + _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
