Align stubs for external and common global variables to pointer size.

This patch fixes PR36885: clang++ generates unaligned stub symbol
holding a pointer.

Patch by Rahul Chaudhry!

llvm-svn: 329030

diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index da4244b..2926ea6 100644 (file)
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -1336,6 +1336,7 @@ bool AsmPrinter::doFinalization(Module &M) {
       OutStreamer->SwitchSection(TLOF.getDataSection());
       const DataLayout &DL = M.getDataLayout();
 
+      EmitAlignment(Log2_32(DL.getPointerSize()));
       for (const auto &Stub : Stubs) {
         OutStreamer->EmitLabel(Stub.first);
         OutStreamer->EmitSymbolValue(Stub.second.getPointer(),

diff --git a/llvm/test/CodeGen/X86/catch.ll b/llvm/test/CodeGen/X86/catch.ll
index be7466e..5c0bc50 100644 (file)
--- a/llvm/test/CodeGen/X86/catch.ll
+++ b/llvm/test/CodeGen/X86/catch.ll
@@ -3,7 +3,11 @@
 ; PR18390
 ; We used to assert creating this label. The name itself is not critical. It
 ; just needs to be a unique local symbol.
-; CHECK:      .L.Lstr.DW.stub:
+; PR36885
+; The stub symbol should have pointer-size (8 byte) alignment.
+; CHECK:      .data
+; CHECK-NEXT: .p2align 3
+; CHECK-NEXT: .L.Lstr.DW.stub:
 ; CHECK-NEXT: .quad   .Lstr
 
 @str = private unnamed_addr constant [12 x i8] c"NSException\00"