Author: Eli Friedman Date: 2024-06-04T09:24:44-07:00 New Revision: 5ae5774fb0b5cac11af479b0905dfdd5255b4047
URL: https://github.com/llvm/llvm-project/commit/5ae5774fb0b5cac11af479b0905dfdd5255b4047 DIFF: https://github.com/llvm/llvm-project/commit/5ae5774fb0b5cac11af479b0905dfdd5255b4047.diff LOG: [Sema] Fix handling of fields with initializers in nested anonymous unions. (#91692) Make sure we count the anonymous union as an initialized field, so we properly construct the AST. Included bonus testcase Test3, which shows a remaining gap: an anonymous union can contain a partially initialized anonymous struct, and we handle that inconsistently. Fixes #91257 Added: Modified: clang/lib/Sema/SemaInit.cpp clang/test/AST/ast-dump-APValue-anon-union.cpp clang/test/SemaCXX/cxx1y-initializer-aggregates.cpp Removed: ################################################################################ diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp index 79bdc8e9f8783..9ed3e8a0df025 100644 --- a/clang/lib/Sema/SemaInit.cpp +++ b/clang/lib/Sema/SemaInit.cpp @@ -814,19 +814,13 @@ InitListChecker::FillInEmptyInitializations(const InitializedEntity &Entity, if (const RecordType *RType = ILE->getType()->getAs<RecordType>()) { const RecordDecl *RDecl = RType->getDecl(); - if (RDecl->isUnion() && ILE->getInitializedFieldInUnion()) - FillInEmptyInitForField(0, ILE->getInitializedFieldInUnion(), - Entity, ILE, RequiresSecondPass, FillWithNoInit); - else if (RDecl->isUnion() && isa<CXXRecordDecl>(RDecl) && - cast<CXXRecordDecl>(RDecl)->hasInClassInitializer()) { - for (auto *Field : RDecl->fields()) { - if (Field->hasInClassInitializer()) { - FillInEmptyInitForField(0, Field, Entity, ILE, RequiresSecondPass, - FillWithNoInit); - break; - } - } + if (RDecl->isUnion() && ILE->getInitializedFieldInUnion()) { + FillInEmptyInitForField(0, ILE->getInitializedFieldInUnion(), Entity, ILE, + RequiresSecondPass, FillWithNoInit); } else { + assert((!RDecl->isUnion() || !isa<CXXRecordDecl>(RDecl) || + !cast<CXXRecordDecl>(RDecl)->hasInClassInitializer()) && + "We should have computed initialized fields already"); // The fields beyond ILE->getNumInits() are default initialized, so in // order to leave them uninitialized, the ILE is expanded and the extra // fields are then filled with NoInitExpr. @@ -2164,12 +2158,15 @@ void InitListChecker::CheckStructUnionTypes( return; for (RecordDecl::field_iterator FieldEnd = RD->field_end(); Field != FieldEnd; ++Field) { - if (Field->hasInClassInitializer()) { + if (Field->hasInClassInitializer() || + (Field->isAnonymousStructOrUnion() && + Field->getType()->getAsCXXRecordDecl()->hasInClassInitializer())) { StructuredList->setInitializedFieldInUnion(*Field); // FIXME: Actually build a CXXDefaultInitExpr? return; } } + llvm_unreachable("Couldn't find in-class initializer"); } // Value-initialize the first member of the union that isn't an unnamed diff --git a/clang/test/AST/ast-dump-APValue-anon-union.cpp b/clang/test/AST/ast-dump-APValue-anon-union.cpp index 0e6466ee1fd73..ffe14ed7322de 100644 --- a/clang/test/AST/ast-dump-APValue-anon-union.cpp +++ b/clang/test/AST/ast-dump-APValue-anon-union.cpp @@ -36,7 +36,7 @@ void Test() { constexpr U0 u0a{}; // CHECK: | `-VarDecl {{.*}} <col:{{.*}}, col:{{.*}}> col:{{.*}} u0a 'const U0' constexpr listinit - // CHECK-NEXT: | |-value: Union None + // CHECK-NEXT: | |-value: Union .U0::(anonymous union at {{.*}}) Union .f Float 3.141500e+00 constexpr U0 u0b{3.1415f}; // CHECK: | `-VarDecl {{.*}} <col:{{.*}}, col:{{.*}}> col:{{.*}} u0b 'const U0' constexpr listinit diff --git a/clang/test/SemaCXX/cxx1y-initializer-aggregates.cpp b/clang/test/SemaCXX/cxx1y-initializer-aggregates.cpp index 3d5e7726a17e5..03a6800898d18 100644 --- a/clang/test/SemaCXX/cxx1y-initializer-aggregates.cpp +++ b/clang/test/SemaCXX/cxx1y-initializer-aggregates.cpp @@ -77,3 +77,41 @@ namespace use_self { int fib(int n) { return FibTree{n}.v; } } + +namespace nested_union { + union Test1 { + union { + int inner { 42 }; + }; + int outer; + }; + static_assert(Test1{}.inner == 42, ""); + struct Test2 { + union { + struct { + int inner : 32 { 42 }; // expected-warning {{C++20 extension}} + int inner_no_init; + }; + int outer; + }; + }; + static_assert(Test2{}.inner == 42, ""); + static_assert(Test2{}.inner_no_init == 0, ""); + struct Int { int x; }; + struct Test3 { + int x; + union { + struct { // expected-note {{in implicit initialization}} + const int& y; // expected-note {{uninitialized reference member is here}} + int inner : 32 { 42 }; // expected-warning {{C++20 extension}} + }; + int outer; + }; + }; + Test3 test3 = {1}; // expected-error {{reference member of type 'const int &' uninitialized}} + constexpr char f(Test3) { return 1; } // expected-note {{candidate function}} + constexpr char f(Int) { return 2; } // expected-note {{candidate function}} + // FIXME: This shouldn't be ambiguous; either we should reject the declaration + // of Test3, or we should exclude f(Test3) as a candidate. + static_assert(f({1}) == 2, ""); // expected-error {{call to 'f' is ambiguous}} +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
