From 2d30ae2be90c4dad2052045768d5d374b66e41ac Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Wed, 27 Nov 2013 01:18:37 +0000
Subject: Use simple section names for COMDAT sections on COFF.

With this patch we use simple names for COMDAT sections (like .text or .bss).
This matches the MSVC behavior.

When merging it is the COMDAT symbol that is used to decide if two sections
should be merged, so there is no point in building a fancy name.

This survived a bootstrap on mingw32.

llvm-svn: 195798
---
 llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp | 38 ++++++++++-------------
 1 file changed, 17 insertions(+), 21 deletions(-)

(limited to 'llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp')

diff --git a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
index 59d7b570375..229ccfae28a 100644
--- a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -723,33 +723,31 @@ getExplicitSectionGlobal(const GlobalValue *GV, SectionKind Kind,
                          Mangler *Mang, const TargetMachine &TM) const {
   int Selection = 0;
   unsigned Characteristics = getCOFFSectionFlags(Kind);
-  SmallString<128> Name(GV->getSection().c_str());
+  StringRef Name = GV->getSection();
+  StringRef COMDATSymName = "";
   if (GV->isWeakForLinker()) {
     Selection = COFF::IMAGE_COMDAT_SELECT_ANY;
     Characteristics |= COFF::IMAGE_SCN_LNK_COMDAT;
-    Name.append("$");
-    Mang->getNameWithPrefix(Name, GV, false, false);
+    MCSymbol *Sym = getSymbol(*Mang, GV);
+    COMDATSymName = Sym->getName();
   }
   return getContext().getCOFFSection(Name,
                                      Characteristics,
                                      Kind,
-                                     "",
+                                     COMDATSymName,
                                      Selection);
 }
 
-static const char *getCOFFSectionPrefixForUniqueGlobal(SectionKind Kind) {
+static const char *getCOFFSectionNameForUniqueGlobal(SectionKind Kind) {
   if (Kind.isText())
-    return ".text$";
+    return ".text";
   if (Kind.isBSS ())
-    return ".bss$";
-  if (Kind.isThreadLocal()) {
-    // 'LLVM' is just an arbitary string to ensure that the section name gets
-    // sorted in between '.tls$AAA' and '.tls$ZZZ' by the linker.
-    return ".tls$LLVM";
-  }
+    return ".bss";
+  if (Kind.isThreadLocal())
+    return ".tls";
   if (Kind.isWriteable())
-    return ".data$";
-  return ".rdata$";
+    return ".data";
+  return ".rdata";
 }
 
 
@@ -760,16 +758,14 @@ 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()) {
-    const char *Prefix = getCOFFSectionPrefixForUniqueGlobal(Kind);
-    SmallString<128> Name(Prefix, Prefix+strlen(Prefix));
-    Mang->getNameWithPrefix(Name, GV, false, false);
-
+    const char *Name = getCOFFSectionNameForUniqueGlobal(Kind);
     unsigned Characteristics = getCOFFSectionFlags(Kind);
 
     Characteristics |= COFF::IMAGE_SCN_LNK_COMDAT;
-
-    return getContext().getCOFFSection(Name.str(), Characteristics,
-                                       Kind, "", COFF::IMAGE_COMDAT_SELECT_ANY);
+    MCSymbol *Sym = getSymbol(*Mang, GV);
+    return getContext().getCOFFSection(Name, Characteristics,
+                                       Kind, Sym->getName(),
+                                       COFF::IMAGE_COMDAT_SELECT_ANY);
   }
 
   if (Kind.isText())
-- 
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