diff options
-rw-r--r-- | lib/AST/RecordLayoutBuilder.cpp | 13 | ||||
-rw-r--r-- | test/CodeGenCXX/non-empty-class-size-zero.cpp | 21 |
2 files changed, 32 insertions, 2 deletions
diff --git a/lib/AST/RecordLayoutBuilder.cpp b/lib/AST/RecordLayoutBuilder.cpp index 730ec21358..a871c3d176 100644 --- a/lib/AST/RecordLayoutBuilder.cpp +++ b/lib/AST/RecordLayoutBuilder.cpp @@ -1469,8 +1469,17 @@ void RecordLayoutBuilder::LayoutField(const FieldDecl *D) { void RecordLayoutBuilder::FinishLayout(const NamedDecl *D) { // In C++, records cannot be of size 0. - if (Context.getLangOptions().CPlusPlus && Size == 0) - Size = 8; + if (Context.getLangOptions().CPlusPlus && Size == 0) { + if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D)) { + // Compatibility with gcc requires a class (pod or non-pod) + // which is not empty but of size 0; such as having fields of + // array of zero-length, remains of Size 0 + if (RD->isEmpty()) + Size = 8; + } + else + Size = 8; + } // Finally, round the size of the record up to the alignment of the // record itself. uint64_t UnpaddedSize = Size - UnfilledBitsInLastByte; diff --git a/test/CodeGenCXX/non-empty-class-size-zero.cpp b/test/CodeGenCXX/non-empty-class-size-zero.cpp new file mode 100644 index 0000000000..810717bb50 --- /dev/null +++ b/test/CodeGenCXX/non-empty-class-size-zero.cpp @@ -0,0 +1,21 @@ +// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -emit-llvm -o - %s | FileCheck %s +// rdar://8945175 + +struct X { + int array[0]; + int array1[0]; + int array2[0]; + X(); + ~X(); +}; + +struct Y { + int first; + X padding; + int second; +}; + +int main() { +// CHECK: store i32 0, i32* [[RETVAL:%.*]] + return sizeof(Y) -8 ; +} |