Author: Aaron Ballman Date: 2025-08-08T12:11:57+02:00 New Revision: 460ff1eb0ef10a599b96a5a7fa1f4bd3973de4c7
URL: https://github.com/llvm/llvm-project/commit/460ff1eb0ef10a599b96a5a7fa1f4bd3973de4c7 DIFF: https://github.com/llvm/llvm-project/commit/460ff1eb0ef10a599b96a5a7fa1f4bd3973de4c7.diff LOG: [C23] AST equivalence of attributes (#151196) Implicitly declared types (like __NSConstantString_tag, etc) will be declared with visibility attributes. This causes problems when merging ASTs because we currently reject declaration merging for declarations with attributes. This relaxes that restriction somewhat; implicit declarations can now have attributes when merging; we assume that if the compiler generated it, it's fine. (cherry picked from commit 30a5d569b2102bba1cfb5d253bd73ec2ebce7ee0) Added: Modified: clang/lib/AST/ASTStructuralEquivalence.cpp clang/test/ASTMerge/enum/test2.c Removed: ################################################################################ diff --git a/clang/lib/AST/ASTStructuralEquivalence.cpp b/clang/lib/AST/ASTStructuralEquivalence.cpp index d46f60facc8d6..25d19a3dcd486 100644 --- a/clang/lib/AST/ASTStructuralEquivalence.cpp +++ b/clang/lib/AST/ASTStructuralEquivalence.cpp @@ -456,7 +456,9 @@ CheckStructurallyEquivalentAttributes(StructuralEquivalenceContext &Context, const Decl *D1, const Decl *D2, const Decl *PrimaryDecl = nullptr) { // If either declaration has an attribute on it, we treat the declarations - // as not being structurally equivalent. + // as not being structurally equivalent unless both declarations are implicit + // (ones generated by the compiler like __NSConstantString_tag). + // // FIXME: this should be handled on a case-by-case basis via tablegen in // Attr.td. There are multiple cases to consider: one declaration with the // attribute, another without it; diff erent attribute syntax|spellings for @@ -468,7 +470,7 @@ CheckStructurallyEquivalentAttributes(StructuralEquivalenceContext &Context, D1Attr = *D1->getAttrs().begin(); if (D2->hasAttrs()) D2Attr = *D2->getAttrs().begin(); - if (D1Attr || D2Attr) { + if ((D1Attr || D2Attr) && !D1->isImplicit() && !D2->isImplicit()) { const auto *DiagnoseDecl = cast<TypeDecl>(PrimaryDecl ? PrimaryDecl : D2); Context.Diag2(DiagnoseDecl->getLocation(), diag::warn_odr_tag_type_with_attributes) diff --git a/clang/test/ASTMerge/enum/test2.c b/clang/test/ASTMerge/enum/test2.c index 2955d8fe50b2e..bdd8b13ee4c21 100644 --- a/clang/test/ASTMerge/enum/test2.c +++ b/clang/test/ASTMerge/enum/test2.c @@ -1,9 +1,7 @@ // RUN: %clang_cc1 -std=c23 -emit-pch -o %t.1.ast %S/Inputs/enum3.c // RUN: %clang_cc1 -std=c23 -emit-pch -o %t.2.ast %S/Inputs/enum4.c -// RUN: not %clang_cc1 -std=c23 -ast-merge %t.1.ast -ast-merge %t.2.ast -fsyntax-only %s 2>&1 | FileCheck %s +// RUN: %clang_cc1 -std=c23 -ast-merge %t.1.ast -ast-merge %t.2.ast -fsyntax-only %s 2>&1 | FileCheck %s -// FIXME: this error should not happen! -// CHECK: error: type 'struct __NSConstantString_tag' has an attribute which currently causes the types to be treated as though they are incompatible // CHECK: enum3.c:2:6: warning: type 'enum E1' has incompatible definitions in diff erent translation units // CHECK: enum4.c:2:6: note: enumeration 'E1' missing fixed underlying type here // CHECK: enum3.c:2:6: note: enumeration 'E1' has fixed underlying type here @@ -12,5 +10,5 @@ // CHECK: enum3.c:6:6: note: enumeration 'E2' missing fixed underlying type here // CHECK: enum3.c:11:6: warning: type 'enum E3' has incompatible definitions in diff erent translation units // CHECK: enum3.c:11:6: note: enumeration 'E3' declared with incompatible fixed underlying types ('long' vs. 'short') -// CHECK: 3 warnings and 1 error generated +// CHECK: 3 warnings generated _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
