Mark MS inline ASM 'nodplicate' it it has labels (PR23715)

Duplicating it can lead to labels being defined twice.

Differential revision: http://reviews.llvm.org/D15399

llvm-svn: 255201

1 files changed, 9 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/CGStmt.cpp b/clang/lib/CodeGen/CGStmt.cpp
index b0ca80e9414..aae867bd3f8 100644
--- a/clang/lib/CodeGen/CGStmt.cpp
+++ b/clang/lib/CodeGen/CGStmt.cpp
@@ -1999,6 +1999,15 @@ void CodeGenFunction::EmitAsmStmt(const AsmStmt &S) {
   Result->addAttribute(llvm::AttributeSet::FunctionIndex,
                        llvm::Attribute::NoUnwind);
 
+  if (isa<MSAsmStmt>(&S)) {
+    // If the assembly contains any labels, mark the call noduplicate to prevent
+    // defining the same ASM label twice (PR23715). This is pretty hacky, but it
+    // works.
+    if (AsmString.find("__MSASMLABEL_") != std::string::npos)
+      Result->addAttribute(llvm::AttributeSet::FunctionIndex,
+                           llvm::Attribute::NoDuplicate);
+  }
+
   // Attach readnone and readonly attributes.
   if (!HasSideEffect) {
     if (ReadNone)