Merging r195148:

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r195148 | rafael | 2013-11-19 11:52:52 -0800 (Tue, 19 Nov 2013) | 15 lines

Support multiple COFF sections with the same name but different COMDAT.

This is the first step to fix pr17918.

It extends the .section directive a bit, inspired by what the ELF one looks
like. The problem with using linkonce is that given

.section foo
.linkonce....

.section foo
.linkonce

we would already have switched sections when getting to .linkonce. The cleanest
solution seems to be to add the comdat information in the .section itself.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_34@195822 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 18 insertions, 4 deletions

diff --git a/include/llvm/MC/MCContext.h b/include/llvm/MC/MCContext.h
index 8fba18c..c8b6626 100644
--- a/include/llvm/MC/MCContext.h
+++ b/include/llvm/MC/MCContext.h
@@ -258,9 +258,15 @@ namespace llvm {
 
     const MCSectionCOFF *getCOFFSection(StringRef Section,
                                         unsigned Characteristics,
-                                        SectionKind Kind, int Selection = 0,
+                                        SectionKind Kind,
+                                        StringRef COMDATSymName,
+                                        int Selection,
                                         const MCSectionCOFF *Assoc = 0);
 
+    const MCSectionCOFF *getCOFFSection(StringRef Section,
+                                        unsigned Characteristics,
+                                        SectionKind Kind);
+
     const MCSectionCOFF *getCOFFSection(StringRef Section);
 
     /// @}
diff --git a/include/llvm/MC/MCSectionCOFF.h b/include/llvm/MC/MCSectionCOFF.h
index 754e829..45c84ae 100644
--- a/include/llvm/MC/MCSectionCOFF.h
+++ b/include/llvm/MC/MCSectionCOFF.h
@@ -19,6 +19,7 @@
 #include "llvm/Support/COFF.h"
 
 namespace llvm {
+class MCSymbol;
 
 /// MCSectionCOFF - This represents a section on Windows
   class MCSectionCOFF : public MCSection {
@@ -32,6 +33,11 @@ namespace llvm {
     /// drawn from the enums below.
     mutable unsigned Characteristics;
 
+    /// The COMDAT symbol of this section. Only valid if this is a COMDAT
+    /// section. Two COMDAT sections are merged if they have the same
+    /// COMDAT symbol.
+    const MCSymbol *COMDATSymbol;
+
     /// Selection - This is the Selection field for the section symbol, if
     /// it is a COMDAT section (Characteristics & IMAGE_SCN_LNK_COMDAT) != 0
     mutable int Selection;
@@ -44,9 +50,11 @@ namespace llvm {
   private:
     friend class MCContext;
     MCSectionCOFF(StringRef Section, unsigned Characteristics,
-                  int Selection, const MCSectionCOFF *Assoc, SectionKind K)
-      : MCSection(SV_COFF, K), SectionName(Section),
-        Characteristics(Characteristics), Selection(Selection), Assoc(Assoc) {
+                  const MCSymbol *COMDATSymbol, int Selection,
+                  const MCSectionCOFF *Assoc, SectionKind K)
+        : MCSection(SV_COFF, K), SectionName(Section),
+          Characteristics(Characteristics), COMDATSymbol(COMDATSymbol),
+          Selection(Selection), Assoc(Assoc) {
       assert ((Characteristics & 0x00F00000) == 0 &&
         "alignment must not be set upon section creation");
       assert ((Selection == COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE) ==