Fix to make sure that a comdat group gets generated correctly for a static member

of instantiated C++ templates.

Patch by Kristof Beyls!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151250 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 34 insertions, 1 deletions

diff --git a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
index 273f6b6162..9925185be1 100644
--- a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -188,6 +188,7 @@ getExplicitSectionGlobal(const GlobalValue *GV, SectionKind Kind,
 static const char *getSectionPrefixForGlobal(SectionKind Kind) {
   if (Kind.isText())                 return ".text.";
   if (Kind.isReadOnly())             return ".rodata.";
+  if (Kind.isBSS())                  return ".bss.";
 
   if (Kind.isThreadData())           return ".tdata.";
   if (Kind.isThreadBSS())            return ".tbss.";
@@ -216,7 +217,7 @@ SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
   // If this global is linkonce/weak and the target handles this by emitting it
   // into a 'uniqued' section name, create and return the section now.
   if ((GV->isWeakForLinker() || EmitUniquedSection) &&
-      !Kind.isCommon() && !Kind.isBSS()) {
+      !Kind.isCommon()) {
     const char *Prefix;
     Prefix = getSectionPrefixForGlobal(Kind);
 
diff --git a/test/CodeGen/ARM/odr_comdat.ll b/test/CodeGen/ARM/odr_comdat.ll
new file mode 100644
index 0000000000..a1fcc9bfc2
--- /dev/null
+++ b/test/CodeGen/ARM/odr_comdat.ll
@@ -0,0 +1,16 @@
+; RUN: llc < %s -mtriple=arm-linux-gnueabi        | FileCheck %s -check-prefix=ARMGNUEABI
+
+; Checking that a comdat group gets generated correctly for a static member 
+; of instantiated C++ templates.
+; see http://sourcery.mentor.com/public/cxx-abi/abi.html#vague-itemplate
+; section 5.2.6 Instantiated templates
+; "Any static member data object is emitted in a COMDAT identified by its mangled 
+;  name, in any object file with a reference to its name symbol."
+
+; Case 1: variable is not explicitly initialized, and ends up in a .bss section
+; ARMGNUEABI: .section        .bss._ZN1CIiE1iE,"aGw",%nobits,_ZN1CIiE1iE,comdat
+@_ZN1CIiE1iE = weak_odr global i32 0, align 4
+
+; Case 2: variable is explicitly initialized, and ends up in a .data section
+; ARMGNUEABI: .section        .data._ZN1CIiE1jE,"aGw",%progbits,_ZN1CIiE1jE,comdat
+@_ZN1CIiE1jE = weak_odr global i32 12, align 4
diff --git a/test/CodeGen/X86/odr_comdat.ll b/test/CodeGen/X86/odr_comdat.ll
new file mode 100644
index 0000000000..547334c045
--- /dev/null
+++ b/test/CodeGen/X86/odr_comdat.ll
@@ -0,0 +1,16 @@
+; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu | FileCheck %s -check-prefix=X86LINUX
+
+; Checking that a comdat group gets generated correctly for a static member 
+; of instantiated C++ templates.
+; see http://sourcery.mentor.com/public/cxx-abi/abi.html#vague-itemplate
+; section 5.2.6 Instantiated templates
+; "Any static member data object is emitted in a COMDAT identified by its mangled 
+;  name, in any object file with a reference to its name symbol."
+
+; Case 1: variable is not explicitly initialized, and ends up in a .bss section
+; X86LINUX:   .section        .bss._ZN1CIiE1iE,"aGw",@nobits,_ZN1CIiE1iE,comdat
+@_ZN1CIiE1iE = weak_odr global i32 0, align 4
+
+; Case 2: variable is explicitly initialized, and ends up in a .data section
+; X86LINUX:   .section        .data._ZN1CIiE1jE,"aGw",@progbits,_ZN1CIiE1jE,comdat
+@_ZN1CIiE1jE = weak_odr global i32 12, align 4