Author: Sirraide Date: 2025-04-16T14:08:59+02:00 New Revision: 616613c80b75614736d0781d12c0e1237d79738f
URL: https://github.com/llvm/llvm-project/commit/616613c80b75614736d0781d12c0e1237d79738f DIFF: https://github.com/llvm/llvm-project/commit/616613c80b75614736d0781d12c0e1237d79738f.diff LOG: [Clang] [Sema] Fix a crash when a `friend` function is redefined as deleted (#135679) NB: This only fixes the crash introduced in Clang 19; we still accept this code even though we shouldn’t: ```c++ struct S { friend int f() { return 3; } friend int f() = delete; }; ``` I tried figuring out a way to diagnose this redeclaration, but it seems tricky because I kept running into issues around defaulted comparison operators. From my testing, however, this fix here would still be required even once we do start diagnosing this. Fixes #135506. Added: Modified: clang/docs/ReleaseNotes.rst clang/lib/Sema/SemaDecl.cpp clang/test/SemaCXX/cxx2c-delete-with-message.cpp Removed: ################################################################################ diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 5af4c08f64cd8..0891fd058bb57 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -425,6 +425,8 @@ Bug Fixes in This Version - Fixed a clang 20 regression where diagnostics attached to some calls to member functions using C++23 "deducing this" did not have a diagnostic location (#GH135522) +- Fixed a crash when a ``friend`` function is redefined as deleted. (#GH135506) + Bug Fixes to Compiler Builtins ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp index 5f811c824e11d..127c0a4500a43 100644 --- a/clang/lib/Sema/SemaDecl.cpp +++ b/clang/lib/Sema/SemaDecl.cpp @@ -16199,16 +16199,11 @@ Decl *Sema::ActOnFinishFunctionBody(Decl *dcl, Stmt *Body, // This is meant to pop the context added in ActOnStartOfFunctionDef(). ExitFunctionBodyRAII ExitRAII(*this, isLambdaCallOperator(FD)); if (FD) { - // If this is called by Parser::ParseFunctionDefinition() after marking - // the declaration as deleted, and if the deleted-function-body contains - // a message (C++26), then a DefaultedOrDeletedInfo will have already been - // added to store that message; do not overwrite it in that case. - // - // Since this would always set the body to 'nullptr' in that case anyway, - // which is already done when the function decl is initially created, - // always skipping this irrespective of whether there is a delete message - // should not be a problem. - if (!FD->isDeletedAsWritten()) + // The function body and the DefaultedOrDeletedInfo, if present, use + // the same storage; don't overwrite the latter if the former is null + // (the body is initialised to null anyway, so even if the latter isn't + // present, this would still be a no-op). + if (Body) FD->setBody(Body); FD->setWillHaveBody(false); diff --git a/clang/test/SemaCXX/cxx2c-delete-with-message.cpp b/clang/test/SemaCXX/cxx2c-delete-with-message.cpp index 22e65d902ecd4..5609da18c05aa 100644 --- a/clang/test/SemaCXX/cxx2c-delete-with-message.cpp +++ b/clang/test/SemaCXX/cxx2c-delete-with-message.cpp @@ -271,3 +271,33 @@ void operators() { if (to_int_int) {} // expected-error {{attempt to use a deleted function: deleted (TO<int, int>, operator bool)}} static_cast<bool>(to_int_int); // expected-error {{static_cast from 'TO<int, int>' to 'bool' uses deleted function: deleted (TO<int, int>, operator bool)}} }; + +namespace gh135506 { +struct a { + // FIXME: We currently don't diagnose these invalid redeclarations if the + // second declaration is defaulted or deleted. This probably needs to be + // handled in ParseCXXInlineMethodDef() after parsing the defaulted/deleted + // body. + friend consteval int f() { return 3; } + friend consteval int f() = delete("foo"); + + friend consteval int g() { return 3; } + friend consteval int g() = delete; + + friend int h() { return 3; } + friend int h() = delete; + + friend consteval int i() = delete; // expected-note {{previous definition is here}} + friend consteval int i() { return 3; } // expected-error {{redefinition of 'i'}} +}; + +struct b { + friend consteval bool operator==(b, b) { return true; } // expected-note {{previous declaration is here}} + friend consteval bool operator==(b, b) = default; // expected-error {{defaulting this equality comparison operator is not allowed because it was already declared outside the class}} +}; + +struct c { + friend consteval bool operator==(c, c) = default; // expected-note {{previous definition is here}} + friend consteval bool operator==(c, c) { return true; } // expected-error {{redefinition of 'operator=='}} +}; +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
