From c44d71b8df9b00853c439d317563500b634068c1 Mon Sep 17 00:00:00 2001
From: Saleem Abdulrasool <compnerd@compnerd.org>
Date: Tue, 27 Jan 2015 22:57:39 +0000
Subject: SymbolRewriter: allow rewriting with comdats

COMDATs must be identically named to the symbol.  When support for COMDATs was
introduced, the symbol rewriter was not updated, resulting in rewriting failing
for symbols which were placed into COMDATs.  This corrects the behaviour and
adds test cases for this.

llvm-svn: 227261
---
 llvm/lib/Transforms/Utils/SymbolRewriter.cpp | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

(limited to 'llvm/lib')

diff --git a/llvm/lib/Transforms/Utils/SymbolRewriter.cpp b/llvm/lib/Transforms/Utils/SymbolRewriter.cpp
index c93cdc4b52e..d36283ea3ae 100644
--- a/llvm/lib/Transforms/Utils/SymbolRewriter.cpp
+++ b/llvm/lib/Transforms/Utils/SymbolRewriter.cpp
@@ -79,6 +79,19 @@ static cl::list<std::string> RewriteMapFiles("rewrite-map-file",
 
 namespace llvm {
 namespace SymbolRewriter {
+void rewriteComdat(Module &M, GlobalObject *GO, const std::string &Source,
+                   const std::string &Target) {
+  if (Comdat *CD = GO->getComdat()) {
+    auto &Comdats = M.getComdatSymbolTable();
+
+    Comdat *C = M.getOrInsertComdat(Target);
+    C->setSelectionKind(CD->getSelectionKind());
+    GO->setComdat(C);
+
+    Comdats.erase(Comdats.find(Source));
+  }
+}
+
 template <RewriteDescriptor::Type DT, typename ValueType,
           ValueType *(llvm::Module::*Get)(StringRef) const>
 class ExplicitRewriteDescriptor : public RewriteDescriptor {
@@ -102,10 +115,14 @@ template <RewriteDescriptor::Type DT, typename ValueType,
 bool ExplicitRewriteDescriptor<DT, ValueType, Get>::performOnModule(Module &M) {
   bool Changed = false;
   if (ValueType *S = (M.*Get)(Source)) {
+    if (GlobalObject *GO = dyn_cast<GlobalObject>(S))
+      rewriteComdat(M, GO, Source, Target);
+
     if (Value *T = (M.*Get)(Target))
       S->setValueName(T->getValueName());
     else
       S->setName(Target);
+
     Changed = true;
   }
   return Changed;
@@ -148,6 +165,9 @@ performOnModule(Module &M) {
     if (C.getName() == Name)
       continue;
 
+    if (GlobalObject *GO = dyn_cast<GlobalObject>(&C))
+      rewriteComdat(M, GO, C.getName(), Name);
+
     if (Value *V = (M.*Get)(Name))
       C.setValueName(V->getValueName());
     else
-- 
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