[Clang][Sema] Diagnosis for constexpr constructor not initializing a union member #81042
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llvmbot
added
clang
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@llvm/pr-subscribers-clang Author: None (mahtohappy) ChangesFull diff: https://github.com/llvm/llvm-project/pull/81042.diff 3 Files Affected:
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 5adc262cd6bc9..ef4e274389f60 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -2393,6 +2393,25 @@ static bool CheckConstexprFunctionBody(Sema &SemaRef, const FunctionDecl *Dcl,
Kind))
return false;
}
+ } else if(!Constructor->isDelegatingConstructor()){
+ for(const Decl* decl : RD->decls()){
+ if(const auto* inner = dyn_cast<CXXRecordDecl>(decl)){
+ if(inner->isUnion()){
+ if (Constructor->getNumCtorInitializers() == 0 &&
+ RD->hasVariantMembers()) {
+ if (Kind == Sema::CheckConstexprKind::Diagnose) {
+ SemaRef.Diag(
+ Dcl->getLocation(),
+ SemaRef.getLangOpts().CPlusPlus20
+ ? diag::warn_cxx17_compat_constexpr_union_ctor_no_init
+ : diag::ext_constexpr_union_ctor_no_init);
+ } else if (!SemaRef.getLangOpts().CPlusPlus20) {
+ return false;
+ }
+ }
+ }
+ }
+ }
}
} else {
if (ReturnStmts.empty()) {
diff --git a/clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p4.cpp b/clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p4.cpp
index f1f677ebfcd34..0d9b4d740a7c1 100644
--- a/clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p4.cpp
+++ b/clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p4.cpp
@@ -224,6 +224,9 @@ struct TemplateInit {
};
// FIXME: This is ill-formed (no diagnostic required). We should diagnose it.
constexpr TemplateInit() {} // desired-error {{must initialize all members}}
+#ifndef CXX2A
+ // expected-error@226 {{constexpr union constructor that does not initialize any member is a C++20 extension}}
+#endif
};
template<typename T> struct TemplateInit2 {
Literal l;
diff --git a/clang/test/SemaCXX/constexpr-union-temp-ctor-cxx.cpp b/clang/test/SemaCXX/constexpr-union-temp-ctor-cxx.cpp
new file mode 100644
index 0000000000000..1300641f28f1c
--- /dev/null
+++ b/clang/test/SemaCXX/constexpr-union-temp-ctor-cxx.cpp
@@ -0,0 +1,18 @@
+// RUN: %clang_cc1 -std=c++14 -verify -fcxx-exceptions -Werror=c++14-extensions -Werror=c++20-extensions %s
+
+template <class> struct C {
+ union {
+ int i;
+ };
+ constexpr C() {} // expected-error {{constexpr union constructor that does not initialize any member is a C++20 extension}}
+};
+constexpr C<int> c;
+
+template <class> class D {
+ union {
+ int i;
+ };
+public:
+ constexpr D() {} // expected-error {{constexpr union constructor that does not initialize any member is a C++20 extension}}
+};
+constexpr D<int> d;
\ No newline at end of file
|
mahtohappy
changed the title
mahtohappy
changed the title
You can test this locally with the following command:git-clang-format --diff a24b0c351a75a87410203dd3777c0d8ee87f65c1 45f86f60044dfe5e53782896b7ad450a8817a1f4 -- clang/test/CXX/dcl.decl/dcl.meaning/dcl.fct/p23.cpp clang/test/Sema/conversion-implicit-int-includes-64-to-32.c clang/test/SemaCXX/constexpr-union-temp-ctor-cxx.cpp mlir/unittests/IR/AffineMapTest.cpp clang-tools-extra/clang-move/Move.cpp clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.cpp clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.h clang-tools-extra/clang-tidy/altera/KernelNameRestrictionCheck.cpp clang-tools-extra/clang-tidy/bugprone/SuspiciousIncludeCheck.cpp clang-tools-extra/clang-tidy/llvm/IncludeOrderCheck.cpp clang-tools-extra/clang-tidy/llvmlibc/RestrictSystemLibcHeadersCheck.cpp clang-tools-extra/clang-tidy/misc/HeaderIncludeCycleCheck.cpp clang-tools-extra/clang-tidy/modernize/DeprecatedHeadersCheck.cpp clang-tools-extra/clang-tidy/modernize/MacroToEnumCheck.cpp clang-tools-extra/clang-tidy/portability/RestrictSystemIncludesCheck.cpp clang-tools-extra/clang-tidy/portability/RestrictSystemIncludesCheck.h clang-tools-extra/clang-tidy/readability/DuplicateIncludeCheck.cpp clang-tools-extra/clang-tidy/utils/IncludeInserter.cpp clang-tools-extra/clangd/Headers.cpp clang-tools-extra/clangd/ParsedAST.cpp clang-tools-extra/clangd/index/IndexAction.cpp clang-tools-extra/clangd/unittests/ReplayPeambleTests.cpp clang-tools-extra/include-cleaner/lib/Record.cpp clang-tools-extra/modularize/CoverageChecker.cpp clang-tools-extra/modularize/PreprocessorTracker.cpp clang-tools-extra/pp-trace/PPCallbacksTracker.cpp clang-tools-extra/pp-trace/PPCallbacksTracker.h clang-tools-extra/test/pp-trace/pp-trace-include.cpp clang/include/clang/AST/DeclTemplate.h clang/include/clang/Lex/PPCallbacks.h clang/include/clang/Lex/PreprocessingRecord.h clang/include/clang/Tooling/DependencyScanning/ModuleDepCollector.h clang/lib/AST/DeclPrinter.cpp clang/lib/AST/ExprConstant.cpp clang/lib/AST/Interp/ByteCodeEmitter.cpp clang/lib/AST/Interp/ByteCodeExprGen.cpp clang/lib/AST/Interp/ByteCodeExprGen.h clang/lib/CodeGen/CGBuiltin.cpp clang/lib/CodeGen/CGExprScalar.cpp clang/lib/CodeGen/MacroPPCallbacks.cpp clang/lib/CodeGen/MacroPPCallbacks.h clang/lib/Frontend/DependencyFile.cpp clang/lib/Frontend/DependencyGraph.cpp clang/lib/Frontend/ModuleDependencyCollector.cpp clang/lib/Frontend/PrecompiledPreamble.cpp clang/lib/Frontend/PrintPreprocessedOutput.cpp clang/lib/Frontend/Rewrite/InclusionRewriter.cpp clang/lib/Lex/PPDirectives.cpp clang/lib/Lex/PreprocessingRecord.cpp clang/lib/Parse/ParseOpenACC.cpp clang/lib/Sema/SemaChecking.cpp clang/lib/Sema/SemaDecl.cpp clang/lib/Sema/SemaDeclCXX.cpp clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp clang/lib/Tooling/DependencyScanning/ModuleDepCollector.cpp clang/test/AST/Interp/builtin-functions.cpp clang/test/AST/Interp/lambda.cpp clang/test/AST/Interp/records.cpp clang/test/AST/ast-print-method-decl.cpp clang/test/Analysis/Inputs/std-c-library-functions-POSIX.h clang/test/Analysis/std-c-library-functions-POSIX.c clang/test/Analysis/std-c-library-functions.c clang/test/Analysis/stream-error.c clang/test/Analysis/stream-noopen.c clang/test/Analysis/stream.c clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p4.cpp clang/test/OpenMP/for_loop_auto.cpp clang/test/Sema/conversion-64-32.c clang/tools/libclang/Indexing.cpp clang/unittests/Lex/PPCallbacksTest.cpp flang/include/flang/Lower/ConvertVariable.h flang/include/flang/Optimizer/Builder/HLFIRTools.h flang/lib/Lower/ConvertVariable.cpp flang/lib/Lower/DirectivesCommon.h flang/lib/Lower/OpenACC.cpp flang/lib/Optimizer/Builder/HLFIRTools.cpp flang/lib/Optimizer/Dialect/FIRAttr.cpp flang/lib/Optimizer/HLFIR/IR/HLFIROps.cpp flang/lib/Optimizer/HLFIR/Transforms/ConvertToFIR.cpp flang/lib/Semantics/resolve-names.cpp flang/tools/bbc/bbc.cpp flang/unittests/Optimizer/FortranVariableTest.cpp libcxx/include/__compare/strong_order.h libcxx/include/__compare/weak_order.h libcxx/include/compare libcxx/include/limits libcxx/include/ostream libcxx/include/scoped_allocator libcxx/include/shared_mutex libcxx/include/string libcxx/include/valarray libcxx/include/vector lldb/include/lldb/DataFormatters/FormatManager.h lldb/include/lldb/DataFormatters/TypeSynthetic.h lldb/include/lldb/DataFormatters/VectorIterator.h lldb/include/lldb/lldb-enumerations.h lldb/source/Core/FormatEntity.cpp lldb/source/Core/ValueObjectSyntheticFilter.cpp lldb/source/DataFormatters/FormatManager.cpp lldb/source/DataFormatters/TypeSynthetic.cpp lldb/source/DataFormatters/VectorType.cpp lldb/source/Interpreter/OptionArgParser.cpp lldb/source/Plugins/Language/CPlusPlus/BlockPointer.cpp lldb/source/Plugins/Language/CPlusPlus/Coroutines.cpp lldb/source/Plugins/Language/CPlusPlus/Coroutines.h lldb/source/Plugins/Language/CPlusPlus/GenericBitset.cpp lldb/source/Plugins/Language/CPlusPlus/GenericOptional.cpp lldb/source/Plugins/Language/CPlusPlus/LibCxx.cpp lldb/source/Plugins/Language/CPlusPlus/LibCxx.h lldb/source/Plugins/Language/CPlusPlus/LibCxxAtomic.cpp lldb/source/Plugins/Language/CPlusPlus/LibCxxInitializerList.cpp lldb/source/Plugins/Language/CPlusPlus/LibCxxList.cpp lldb/source/Plugins/Language/CPlusPlus/LibCxxMap.cpp lldb/source/Plugins/Language/CPlusPlus/LibCxxQueue.cpp lldb/source/Plugins/Language/CPlusPlus/LibCxxRangesRefView.cpp lldb/source/Plugins/Language/CPlusPlus/LibCxxSpan.cpp lldb/source/Plugins/Language/CPlusPlus/LibCxxTuple.cpp lldb/source/Plugins/Language/CPlusPlus/LibCxxUnorderedMap.cpp lldb/source/Plugins/Language/CPlusPlus/LibCxxVariant.cpp lldb/source/Plugins/Language/CPlusPlus/LibCxxVector.cpp lldb/source/Plugins/Language/CPlusPlus/LibStdcpp.cpp lldb/source/Plugins/Language/CPlusPlus/LibStdcppTuple.cpp lldb/source/Plugins/Language/CPlusPlus/LibStdcppUniquePointer.cpp lldb/source/Plugins/Language/ObjC/Cocoa.cpp lldb/source/Plugins/Language/ObjC/NSArray.cpp lldb/source/Plugins/Language/ObjC/NSDictionary.cpp lldb/source/Plugins/Language/ObjC/NSError.cpp lldb/source/Plugins/Language/ObjC/NSException.cpp lldb/source/Plugins/Language/ObjC/NSIndexPath.cpp lldb/source/Plugins/Language/ObjC/NSSet.cpp llvm/include/llvm/ADT/ilist_iterator.h llvm/include/llvm/Analysis/ValueTracking.h llvm/include/llvm/CodeGen/SelectionDAG.h llvm/include/llvm/IR/PatternMatch.h llvm/include/llvm/ObjectYAML/XCOFFYAML.h llvm/lib/Analysis/BasicAliasAnalysis.cpp llvm/lib/Analysis/DomConditionCache.cpp llvm/lib/Analysis/ValueTracking.cpp llvm/lib/CodeGen/CodeGenPrepare.cpp llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp llvm/lib/CodeGen/SelectionDAG/FastISel.cpp llvm/lib/CodeGen/ValueTypes.cpp llvm/lib/IR/BasicBlock.cpp llvm/lib/IR/ConstantRange.cpp llvm/lib/ObjectYAML/XCOFFEmitter.cpp llvm/lib/ObjectYAML/XCOFFYAML.cpp llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp llvm/lib/Target/AArch64/AArch64ISelLowering.cpp llvm/lib/Target/AArch64/AArch64InstrInfo.cpp llvm/lib/Target/AArch64/GISel/AArch64CallLowering.cpp llvm/lib/Target/AArch64/GISel/AArch64RegisterBankInfo.cpp llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp llvm/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp llvm/lib/Target/AMDGPU/Disassembler/AMDGPUDisassembler.cpp llvm/lib/Target/AMDGPU/Disassembler/AMDGPUDisassembler.h llvm/lib/Target/AMDGPU/SIFoldOperands.cpp llvm/lib/Target/DirectX/DXILMetadata.cpp llvm/lib/Target/X86/X86FixupVectorConstants.cpp llvm/lib/Target/X86/X86ISelLowering.cpp llvm/lib/Target/X86/X86InstrInfo.cpp llvm/lib/Target/X86/X86InstrInfo.h llvm/lib/Target/X86/X86MCInstLower.cpp llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp llvm/lib/Transforms/InstCombine/InstCombineInternal.h llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp llvm/lib/Transforms/InstCombine/InstructionCombining.cpp llvm/lib/Transforms/Scalar/SROA.cpp llvm/tools/llc/llc.cpp llvm/tools/llvm-link/llvm-link.cpp llvm/tools/llvm-lto/llvm-lto.cpp llvm/tools/llvm-lto2/llvm-lto2.cpp llvm/tools/llvm-reduce/llvm-reduce.cpp llvm/tools/obj2yaml/xcoff2yaml.cpp llvm/tools/opt/optdriver.cpp llvm/unittests/ADT/IListIteratorBitsTest.cpp llvm/unittests/IR/BasicBlockDbgInfoTest.cpp llvm/unittests/IR/ConstantRangeTest.cpp llvm/unittests/IR/PatternMatch.cpp llvm/unittests/Target/RISCV/RISCVInstrInfoTest.cpp llvm/utils/TableGen/DXILEmitter.cpp mlir/include/mlir/Dialect/Bufferization/IR/BufferizableOpInterface.h mlir/include/mlir/Dialect/Utils/StructuredOpsUtils.h mlir/include/mlir/IR/AffineMap.h mlir/lib/Conversion/TosaToLinalg/TosaToLinalg.cpp mlir/lib/Conversion/VectorToGPU/VectorToGPU.cpp mlir/lib/Dialect/Affine/IR/AffineOps.cpp mlir/lib/Dialect/Arith/Transforms/BufferizableOpInterfaceImpl.cpp mlir/lib/Dialect/Bufferization/IR/BufferizableOpInterface.cpp mlir/lib/Dialect/Bufferization/IR/BufferizationOps.cpp mlir/lib/Dialect/Bufferization/Transforms/Bufferize.cpp mlir/lib/Dialect/Bufferization/Transforms/FuncBufferizableOpInterfaceImpl.cpp mlir/lib/Dialect/Linalg/Transforms/Split.cpp mlir/lib/Dialect/Linalg/Utils/Utils.cpp mlir/lib/Dialect/SparseTensor/Transforms/SparseGPUCodegen.cpp mlir/lib/Dialect/SparseTensor/Transforms/Utils/LoopEmitter.cpp mlir/lib/Dialect/SparseTensor/Transforms/Utils/LoopEmitter.h mlir/lib/Dialect/SparseTensor/Transforms/Utils/SparseTensorLevel.cpp mlir/lib/Dialect/SparseTensor/Transforms/Utils/SparseTensorLevel.h mlir/lib/Dialect/Tensor/Transforms/BufferizableOpInterfaceImpl.cpp mlir/lib/Dialect/Vector/IR/VectorOps.cpp mlir/lib/Dialect/Vector/Transforms/LowerVectorContract.cpp mlir/lib/Dialect/Vector/Transforms/VectorTransferSplitRewritePatterns.cpp mlir/lib/Dialect/Vector/Transforms/VectorTransforms.cpp mlir/lib/IR/AffineMap.cpp mlir/lib/IR/BuiltinTypes.cpp mlir/test/lib/Dialect/Bufferization/TestTensorCopyInsertion.cppView the diff from clang-format here.diff --git a/clang/lib/Frontend/PrintPreprocessedOutput.cpp b/clang/lib/Frontend/PrintPreprocessedOutput.cpp
index a26d2c3ab8..4f838362b7 100644
--- a/clang/lib/Frontend/PrintPreprocessedOutput.cpp
+++ b/clang/lib/Frontend/PrintPreprocessedOutput.cpp
@@ -428,9 +428,8 @@ void PrintPPOutputPPCallbacks::InclusionDirective(
*OS << "#pragma clang module import "
<< SuggestedModule->getFullModuleName(true)
<< " /* clang -E: implicit import for "
- << "#" << PP.getSpelling(IncludeTok) << " "
- << (IsAngled ? '<' : '"') << FileName << (IsAngled ? '>' : '"')
- << " */";
+ << "#" << PP.getSpelling(IncludeTok) << " " << (IsAngled ? '<' : '"')
+ << FileName << (IsAngled ? '>' : '"') << " */";
setEmittedDirectiveOnThisLine();
break;
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 8da4f09576..f6c7410e3b 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -1795,10 +1795,11 @@ static bool CheckConstexprFunctionBody(Sema &SemaRef, const FunctionDecl *Dcl,
Stmt *Body,
Sema::CheckConstexprKind Kind);
-static bool checkUnionConstructorIntializer(Sema &SemaRef, const FunctionDecl *Dcl,
- const CXXConstructorDecl *Constructor,
- const CXXRecordDecl *RD,
- Sema::CheckConstexprKind Kind);
+static bool
+checkUnionConstructorIntializer(Sema &SemaRef, const FunctionDecl *Dcl,
+ const CXXConstructorDecl *Constructor,
+ const CXXRecordDecl *RD,
+ Sema::CheckConstexprKind Kind);
// Check whether a function declaration satisfies the requirements of a
// constexpr function definition or a constexpr constructor definition. If so,
diff --git a/llvm/lib/Target/X86/X86FixupVectorConstants.cpp b/llvm/lib/Target/X86/X86FixupVectorConstants.cpp
index da7dcbb25a..ec366eff39 100644
--- a/llvm/lib/Target/X86/X86FixupVectorConstants.cpp
+++ b/llvm/lib/Target/X86/X86FixupVectorConstants.cpp
@@ -272,9 +272,8 @@ static Constant *rebuildZeroUpperCst(const Constant *C, unsigned NumBits,
return nullptr;
}
-static Constant *rebuildExtCst(const Constant *C, bool IsSExt,
- unsigned NumBits, unsigned NumElts,
- unsigned SrcEltBitWidth) {
+static Constant *rebuildExtCst(const Constant *C, bool IsSExt, unsigned NumBits,
+ unsigned NumElts, unsigned SrcEltBitWidth) {
unsigned DstEltBitWidth = NumBits / NumElts;
assert((NumBits % NumElts) == 0 && (NumBits % SrcEltBitWidth) == 0 &&
(DstEltBitWidth % SrcEltBitWidth) == 0 &&
|
mahtohappy
changed the title
shafik
reviewed
Feb 7, 2024
There was a problem hiding this comment.
Thank you the PR.
Your summary is blank but should describe the problem you are trying to solve, how the PR solves it and should at the end link to any llvm issues this relates to.
Having solid summaries is critical since this is normally what one sees when using git log and folks should be able to understand the change without having to goto the PR itself or open up the issue that it solves.
Also please add [Clang][Sema] to the front of your title so folks can quickly see what area it applies to.
Without having looked at the fix in detail, this will also require a release note.
mahtohappy
changed the title
shafik
reviewed
Feb 8, 2024
| public: | ||
| constexpr D() {} // expected-error {{constexpr union constructor that does not initialize any member is a C++20 extension}} | ||
| }; | ||
| constexpr D<int> d; |
There was a problem hiding this comment.
Please add a newline at the end of the file.
| @@ -224,6 +224,9 @@ struct TemplateInit { | |||
| }; | |||
| // FIXME: This is ill-formed (no diagnostic required). We should diagnose it. | |||
| constexpr TemplateInit() {} // desired-error {{must initialize all members}} | |||
| #ifndef CXX2A | |||
There was a problem hiding this comment.
We normally do this using parameters to -verify and using those in the expected line e.g.
https://github.com/llvm/llvm-project/blob/main/clang/test/Parser/cxx2b-lambdas-ext-warns.cpp
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yes, I'm here just following the convention in that file and didn't want to change the run command
https://github.com/llvm/llvm-project/blob/main/clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p4.cpp
Fznamznon
reviewed
Feb 8, 2024
Comment on lines
225
to
226
| // FIXME: This is ill-formed (no diagnostic required). We should diagnose it. | ||
| constexpr TemplateInit() {} // desired-error {{must initialize all members}} |
There was a problem hiding this comment.
We've got the desired error, I think :)
Suggested change
| // FIXME: This is ill-formed (no diagnostic required). We should diagnose it. | |
| constexpr TemplateInit() {} // desired-error {{must initialize all members}} | |
| constexpr TemplateInit() {} |
clang/docs/ReleaseNotes.rst
Outdated
| @@ -150,6 +150,8 @@ Improvements to Clang's diagnostics | |||
|
|
|||
| - Clang now diagnoses member template declarations with multiple declarators. | |||
| - Clang now diagnoses use of the ``template`` keyword after declarative nested name specifiers. | |||
| - Clang now diagnoses constexpr constructor for not initializing atleast one member of union | |||
There was a problem hiding this comment.
Suggested change
| - Clang now diagnoses constexpr constructor for not initializing atleast one member of union | |
| - Clang now diagnoses constexpr constructor for not initializing at least one member of union |
| int i; | ||
| }; | ||
| public: | ||
| constexpr D() {} // expected-error {{constexpr union constructor that does not initialize any member is a C++20 extension}} |
There was a problem hiding this comment.
Can we add a test checking if we do initialize something there is no error?
clang/lib/Sema/SemaDeclCXX.cpp
Outdated
| @@ -2393,6 +2393,25 @@ static bool CheckConstexprFunctionBody(Sema &SemaRef, const FunctionDecl *Dcl, | |||
| Kind)) | |||
| return false; | |||
| } | |||
| } else if (!Constructor->isDelegatingConstructor()) { | |||
| for (const Decl *decl : RD->decls()) { | |||
| if (const auto *inner = dyn_cast<CXXRecordDecl>(decl)) { | |||
There was a problem hiding this comment.
Code-style NIT, the names of the variables should start from a capital.
Suggested change
| if (const auto *inner = dyn_cast<CXXRecordDecl>(decl)) { | |
| if (const auto *Inner = dyn_cast<CXXRecordDecl>(Decl)) { |
clang/lib/Sema/SemaDeclCXX.cpp
Outdated
Comment on lines
2400
to
2410
| if (Constructor->getNumCtorInitializers() == 0 && | ||
| RD->hasVariantMembers()) { | ||
| if (Kind == Sema::CheckConstexprKind::Diagnose) { | ||
| SemaRef.Diag( | ||
| Dcl->getLocation(), | ||
| SemaRef.getLangOpts().CPlusPlus20 | ||
| ? diag::warn_cxx17_compat_constexpr_union_ctor_no_init | ||
| : diag::ext_constexpr_union_ctor_no_init); | ||
| } else if (!SemaRef.getLangOpts().CPlusPlus20) { | ||
| return false; | ||
| } |
There was a problem hiding this comment.
That seems to be copying the check for unions from lines 2346-2354. I also observed that non-template version of the code this patch fixes, works fine now. I wonder, why can't we just do same thing for templated contexts as we do now for non-templated? If that is not possible, because for example it now involves constexpr evaluator and it normally chokes on templates, can we unify the new check with the one from lines 2346-2354?
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by unify you mean, put the check in the new function and call it at that place?
mahtohappy
requested review from
aartbik,
PeimingLiu,
yinying-lisa-li,
matthias-springer,
hanhanW,
nicolasvasilache,
dcaballe,
JDevlieghere,
nikic and
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For templates, isDependentContext() is true, that's why the previous if check was failing.
Here, we traverse the RD and upon finding a Union declaration we check if at least one member of the union is initialized.
If not, it produces a diagnosis for it.
Fixes #46689