IR: Add COMDATs to the IR

This new IR facility allows us to represent the object-file semantic of
a COMDAT group.

COMDATs allow us to tie together sections and make the inclusion of one
dependent on another. This is required to implement features like MS
ABI VFTables and optimizing away certain kinds of initialization in C++.

This functionality is only representable in COFF and ELF, Mach-O has no
similar mechanism.

Differential Revision: http://reviews.llvm.org/D4178

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211920 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 0 deletions

diff --git a/lib/IR/AsmWriter.h b/lib/IR/AsmWriter.h
index b4ce6de10d..aef9c8a3e9 100644
--- a/lib/IR/AsmWriter.h
+++ b/lib/IR/AsmWriter.h
@@ -16,6 +16,7 @@
 #define LLVM_IR_ASSEMBLYWRITER_H
 
 #include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SetVector.h"
 #include "llvm/IR/Attributes.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/TypeFinder.h"
@@ -26,6 +27,7 @@ namespace llvm {
 class BasicBlock;
 class Function;
 class GlobalValue;
+class Comdat;
 class Module;
 class NamedMDNode;
 class Value;
@@ -70,6 +72,7 @@ private:
   SlotTracker &Machine;
   TypePrinting TypePrinter;
   AssemblyAnnotationWriter *AnnotationWriter;
+  SetVector<const Comdat *> Comdats;
 
 public:
   /// Construct an AssemblyWriter with an external SlotTracker
@@ -101,6 +104,7 @@ public:
   void printTypeIdentities();
   void printGlobal(const GlobalVariable *GV);
   void printAlias(const GlobalAlias *GV);
+  void printComdat(const Comdat *C);
   void printFunction(const Function *F);
   void printArgument(const Argument *FA, AttributeSet Attrs, unsigned Idx);
   void printBasicBlock(const BasicBlock *BB);