[llvm] r210298 - Correctly set the comdat symbol on COFF.
Rafael Espindola
rafael.espindola at gmail.com
Thu Jun 5 16:09:26 PDT 2014
Author: rafael
Date: Thu Jun 5 18:09:25 2014
New Revision: 210298
URL: http://llvm.org/viewvc/llvm-project?rev=210298&view=rev
Log:
Correctly set the comdat symbol on COFF.
We extended the .section syntax to allow multiple sections with the
same name but different comdats, but currently we don't make sure that
the output section has that comdat symbol.
That happens to work with the code llc produces currently because it looks like
.section secName, "dr", one_only, "COMDATSym"
.globl COMDATSym
COMDATSym:
....
but that is not very friendly to anyone coding in assembly or even to
llc once we get comdat support in the IR.
This patch changes the coff object writer to make sure the comdat symbol is
output just after the section symbol, as required by the coff spec.
Added:
llvm/trunk/test/MC/COFF/section-comdat-conflict.s
Modified:
llvm/trunk/include/llvm/MC/MCSectionCOFF.h
llvm/trunk/lib/MC/WinCOFFObjectWriter.cpp
llvm/trunk/test/MC/COFF/section-comdat.s
Modified: llvm/trunk/include/llvm/MC/MCSectionCOFF.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/MC/MCSectionCOFF.h?rev=210298&r1=210297&r2=210298&view=diff
==============================================================================
--- llvm/trunk/include/llvm/MC/MCSectionCOFF.h (original)
+++ llvm/trunk/include/llvm/MC/MCSectionCOFF.h Thu Jun 5 18:09:25 2014
@@ -76,6 +76,7 @@ class MCSymbol;
return SectionName.str() + "_end";
}
unsigned getCharacteristics() const { return Characteristics; }
+ const MCSymbol *getCOMDATSymbol() const { return COMDATSymbol; }
int getSelection() const { return Selection; }
const MCSectionCOFF *getAssocSection() const { return Assoc; }
Modified: llvm/trunk/lib/MC/WinCOFFObjectWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/WinCOFFObjectWriter.cpp?rev=210298&r1=210297&r2=210298&view=diff
==============================================================================
--- llvm/trunk/lib/MC/WinCOFFObjectWriter.cpp (original)
+++ llvm/trunk/lib/MC/WinCOFFObjectWriter.cpp Thu Jun 5 18:09:25 2014
@@ -347,6 +347,11 @@ void WinCOFFObjectWriter::DefineSection(
COFFSection *coff_section = createSection(Sec.getSectionName());
COFFSymbol *coff_symbol = createSymbol(Sec.getSectionName());
+ if (const MCSymbol *S = Sec.getCOMDATSymbol()) {
+ COFFSymbol *COMDATSymbol = GetOrCreateCOFFSymbol(S);
+ assert(!COMDATSymbol->Section);
+ COMDATSymbol->Section = coff_section;
+ }
coff_section->Symbol = coff_symbol;
coff_symbol->Section = coff_section;
@@ -458,9 +463,15 @@ void WinCOFFObjectWriter::DefineSymbol(M
coff_symbol->Data.SectionNumber = COFF::IMAGE_SYM_ABSOLUTE;
} else {
const MCSymbolData &BaseData = Assembler.getSymbolData(*Base);
- if (BaseData.Fragment)
- coff_symbol->Section =
+ if (BaseData.Fragment) {
+ COFFSection *Sec =
SectionMap[&BaseData.Fragment->getParent()->getSection()];
+
+ if (coff_symbol->Section && coff_symbol->Section != Sec)
+ report_fatal_error("conflicting sections for symbol");
+
+ coff_symbol->Section = Sec;
+ }
}
coff_symbol->MCData = &ResSymData;
Added: llvm/trunk/test/MC/COFF/section-comdat-conflict.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/COFF/section-comdat-conflict.s?rev=210298&view=auto
==============================================================================
--- llvm/trunk/test/MC/COFF/section-comdat-conflict.s (added)
+++ llvm/trunk/test/MC/COFF/section-comdat-conflict.s Thu Jun 5 18:09:25 2014
@@ -0,0 +1,13 @@
+// RUN: not llvm-mc -triple i386-pc-win32 -filetype=obj < %s 2>&1 | FileCheck %s
+
+// CHECK: conflicting sections for symbol
+
+ .section .xyz
+ .global bar
+bar:
+ .long 42
+
+ .section .abcd,"xr",discard,bar
+ .global foo
+foo:
+ .long 42
Modified: llvm/trunk/test/MC/COFF/section-comdat.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/COFF/section-comdat.s?rev=210298&r1=210297&r2=210298&view=diff
==============================================================================
--- llvm/trunk/test/MC/COFF/section-comdat.s (original)
+++ llvm/trunk/test/MC/COFF/section-comdat.s Thu Jun 5 18:09:25 2014
@@ -40,6 +40,11 @@ Symbol6:
Symbol7:
.long 1
+.section SecName, "dr", newest, "Symbol8"
+.globl AnotherSymbol
+AnotherSymbol:
+.long 1
+
// CHECK: Sections [
// CHECK: Section {
// CHECK: Number: 1
@@ -114,6 +119,10 @@ Symbol7:
// CHECK: }
// CHECK: }
// CHECK: Symbol {
+// CHECK: Name: Symbol1
+// CHECK: Section: secName (2)
+// CHECK: }
+// CHECK: Symbol {
// CHECK: Name: secName
// CHECK: Section: secName (3)
// CHECK: AuxSectionDef {
@@ -121,6 +130,10 @@ Symbol7:
// CHECK: }
// CHECK: }
// CHECK: Symbol {
+// CHECK: Name: Symbol2
+// CHECK: Section: secName (3)
+// CHECK: }
+// CHECK: Symbol {
// CHECK: Name: SecName
// CHECK: Section: SecName (4)
// CHECK: AuxSectionDef {
@@ -128,6 +141,10 @@ Symbol7:
// CHECK: }
// CHECK: }
// CHECK: Symbol {
+// CHECK: Name: Symbol3
+// CHECK: Section: SecName (4)
+// CHECK: }
+// CHECK: Symbol {
// CHECK: Name: SecName
// CHECK: Section: SecName (5)
// CHECK: AuxSymbolCount: 1
@@ -136,6 +153,10 @@ Symbol7:
// CHECK: }
// CHECK: }
// CHECK: Symbol {
+// CHECK: Name: Symbol4
+// CHECK: Section: SecName (5)
+// CHECK: }
+// CHECK: Symbol {
// CHECK: Name: SecName
// CHECK: Section: SecName (6)
// CHECK: AuxSectionDef {
@@ -144,6 +165,10 @@ Symbol7:
// CHECK: }
// CHECK: }
// CHECK: Symbol {
+// CHECK: Name: Symbol5
+// CHECK: Section: SecName (6)
+// CHECK: }
+// CHECK: Symbol {
// CHECK: Name: SecName
// CHECK: Section: SecName (7)
// CHECK: AuxSectionDef {
@@ -151,6 +176,10 @@ Symbol7:
// CHECK: }
// CHECK: }
// CHECK: Symbol {
+// CHECK: Name: Symbol6
+// CHECK: Section: SecName (7)
+// CHECK: }
+// CHECK: Symbol {
// CHECK: Name: SecName
// CHECK: Section: SecName (8)
// CHECK: AuxSectionDef {
@@ -158,31 +187,22 @@ Symbol7:
// CHECK: }
// CHECK: }
// CHECK: Symbol {
-// CHECK: Name: Symbol1
-// CHECK: Section: secName (2)
-// CHECK: }
-// CHECK: Symbol {
-// CHECK: Name: Symbol2
-// CHECK: Section: secName (3)
-// CHECK: }
-// CHECK: Symbol {
-// CHECK: Name: Symbol3
-// CHECK: Section: SecName (4)
-// CHECK: }
-// CHECK: Symbol {
-// CHECK: Name: Symbol4
-// CHECK: Section: SecName (5)
+// CHECK: Name: Symbol7
+// CHECK: Section: SecName (8)
// CHECK: }
// CHECK: Symbol {
-// CHECK: Name: Symbol5
-// CHECK: Section: SecName (6)
+// CHECK: Name: SecName
+// CHECK: Section: SecName (9)
+// CHECK: AuxSectionDef {
+// CHECK: Selection: Newest (0x7)
+// CHECK: }
// CHECK: }
// CHECK: Symbol {
-// CHECK: Name: Symbol6
-// CHECK: Section: SecName (7)
+// CHECK: Name: Symbol8
+// CHECK: Section: SecName (9)
// CHECK: }
// CHECK: Symbol {
-// CHECK: Name: Symbol7
-// CHECK: Section: SecName (8)
+// CHECK: Name: AnotherSymbol
+// CHECK: Section: SecName (9)
// CHECK: }
// CHECK: ]
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