Merging r195148:
------------------------------------------------------------------------
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.
------------------------------------------------------------------------
git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_34@195822 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/Extensions.rst b/docs/Extensions.rst
index 925d727..e308dbc 100644
--- a/docs/Extensions.rst
+++ b/docs/Extensions.rst
@@ -105,3 +105,41 @@
.section .xdata$foo
.linkonce associative .text$foo
...
+
+``.section`` Directive
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+MC supports passing the information in ``.linkonce`` at the end of
+``.section``. For example, these two codes are equivalent
+
+.. code-block:: gas
+
+ .section secName, "dr", discard, "Symbol1"
+ .globl Symbol1
+ Symbol1:
+ .long 1
+
+.. code-block:: gas
+
+ .section secName, "dr"
+ .linkonce discard
+ .globl Symbol1
+ Symbol1:
+ .long 1
+
+Note that in the combined form the COMDAT symbol is explict. This
+extension exits to support multiple sections with the same name in
+different comdats:
+
+
+.. code-block:: gas
+
+ .section secName, "dr", discard, "Symbol1"
+ .globl Symbol1
+ Symbol1:
+ .long 1
+
+ .section secName, "dr", discard, "Symbol2"
+ .globl Symbol2
+ Symbol2:
+ .long 1
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 @@
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 @@
/// 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 @@
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) ==
diff --git a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
index 66ba3ec..59d7b57 100644
--- a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -733,6 +733,7 @@
return getContext().getCOFFSection(Name,
Characteristics,
Kind,
+ "",
Selection);
}
@@ -768,7 +769,7 @@
Characteristics |= COFF::IMAGE_SCN_LNK_COMDAT;
return getContext().getCOFFSection(Name.str(), Characteristics,
- Kind, COFF::IMAGE_COMDAT_SELECT_ANY);
+ Kind, "", COFF::IMAGE_COMDAT_SELECT_ANY);
}
if (Kind.isText())
diff --git a/lib/MC/MCContext.cpp b/lib/MC/MCContext.cpp
index 67904f6..3b45d16 100644
--- a/lib/MC/MCContext.cpp
+++ b/lib/MC/MCContext.cpp
@@ -34,8 +34,7 @@
typedef StringMap<const MCSectionMachO*> MachOUniqueMapTy;
typedef std::map<SectionGroupPair, const MCSectionELF *> ELFUniqueMapTy;
-typedef StringMap<const MCSectionCOFF*> COFFUniqueMapTy;
-
+typedef std::map<SectionGroupPair, const MCSectionCOFF *> COFFUniqueMapTy;
MCContext::MCContext(const MCAsmInfo *mai, const MCRegisterInfo *mri,
const MCObjectFileInfo *mofi, const SourceMgr *mgr,
@@ -280,32 +279,51 @@
return Result;
}
-const MCSectionCOFF *MCContext::getCOFFSection(StringRef Section,
- unsigned Characteristics,
- SectionKind Kind, int Selection,
- const MCSectionCOFF *Assoc) {
+const MCSectionCOFF *
+MCContext::getCOFFSection(StringRef Section, unsigned Characteristics,
+ SectionKind Kind, StringRef COMDATSymName,
+ int Selection, const MCSectionCOFF *Assoc) {
if (COFFUniquingMap == 0)
COFFUniquingMap = new COFFUniqueMapTy();
COFFUniqueMapTy &Map = *(COFFUniqueMapTy*)COFFUniquingMap;
// Do the lookup, if we have a hit, return it.
- StringMapEntry<const MCSectionCOFF*> &Entry = Map.GetOrCreateValue(Section);
- if (Entry.getValue()) return Entry.getValue();
- MCSectionCOFF *Result = new (*this) MCSectionCOFF(Entry.getKey(),
- Characteristics,
- Selection, Assoc, Kind);
+ SectionGroupPair P(Section, COMDATSymName);
+ std::pair<COFFUniqueMapTy::iterator, bool> Entry =
+ Map.insert(std::make_pair(P, (MCSectionCOFF *)0));
+ COFFUniqueMapTy::iterator Iter = Entry.first;
+ if (!Entry.second)
+ return Iter->second;
- Entry.setValue(Result);
+ const MCSymbol *COMDATSymbol = NULL;
+ if (!COMDATSymName.empty())
+ COMDATSymbol = GetOrCreateSymbol(COMDATSymName);
+
+ MCSectionCOFF *Result =
+ new (*this) MCSectionCOFF(Iter->first.first, Characteristics,
+ COMDATSymbol, Selection, Assoc, Kind);
+
+ Iter->second = Result;
return Result;
}
+const MCSectionCOFF *
+MCContext::getCOFFSection(StringRef Section, unsigned Characteristics,
+ SectionKind Kind) {
+ return getCOFFSection(Section, Characteristics, Kind, "", 0);
+}
+
const MCSectionCOFF *MCContext::getCOFFSection(StringRef Section) {
if (COFFUniquingMap == 0)
COFFUniquingMap = new COFFUniqueMapTy();
COFFUniqueMapTy &Map = *(COFFUniqueMapTy*)COFFUniquingMap;
- return Map.lookup(Section);
+ SectionGroupPair P(Section, "");
+ COFFUniqueMapTy::iterator Iter = Map.find(P);
+ if (Iter == Map.end())
+ return 0;
+ return Iter->second;
}
//===----------------------------------------------------------------------===//
diff --git a/lib/MC/MCParser/COFFAsmParser.cpp b/lib/MC/MCParser/COFFAsmParser.cpp
index df1794c..d8343a3 100644
--- a/lib/MC/MCParser/COFFAsmParser.cpp
+++ b/lib/MC/MCParser/COFFAsmParser.cpp
@@ -35,6 +35,10 @@
unsigned Characteristics,
SectionKind Kind);
+ bool ParseSectionSwitch(StringRef Section, unsigned Characteristics,
+ SectionKind Kind, StringRef COMDATSymName,
+ COFF::COMDATType Type, const MCSectionCOFF *Assoc);
+
bool ParseSectionName(StringRef &SectionName);
bool ParseSectionFlags(StringRef FlagsString, unsigned* Flags);
@@ -111,6 +115,8 @@
bool ParseDirectiveType(StringRef, SMLoc);
bool ParseDirectiveEndef(StringRef, SMLoc);
bool ParseDirectiveSecRel32(StringRef, SMLoc);
+ bool parseCOMDATTypeAndAssoc(COFF::COMDATType &Type,
+ const MCSectionCOFF *&Assoc);
bool ParseDirectiveLinkOnce(StringRef, SMLoc);
// Win64 EH directives.
@@ -284,12 +290,22 @@
bool COFFAsmParser::ParseSectionSwitch(StringRef Section,
unsigned Characteristics,
SectionKind Kind) {
+ return ParseSectionSwitch(Section, Characteristics, Kind, "",
+ COFF::IMAGE_COMDAT_SELECT_ANY, 0);
+}
+
+bool COFFAsmParser::ParseSectionSwitch(StringRef Section,
+ unsigned Characteristics,
+ SectionKind Kind,
+ StringRef COMDATSymName,
+ COFF::COMDATType Type,
+ const MCSectionCOFF *Assoc) {
if (getLexer().isNot(AsmToken::EndOfStatement))
return TokError("unexpected token in section switching directive");
Lex();
getStreamer().SwitchSection(getContext().getCOFFSection(
- Section, Characteristics, Kind));
+ Section, Characteristics, Kind, COMDATSymName, Type, Assoc));
return false;
}
@@ -303,7 +319,7 @@
return false;
}
-// .section name [, "flags"]
+// .section name [, "flags"] [, identifier [ identifier ], identifier]
//
// Supported flags:
// a: Ignored.
@@ -340,11 +356,30 @@
return true;
}
+ COFF::COMDATType Type = COFF::IMAGE_COMDAT_SELECT_ANY;
+ const MCSectionCOFF *Assoc = 0;
+ StringRef COMDATSymName;
+ if (getLexer().is(AsmToken::Comma)) {
+ Lex();
+
+ Flags |= COFF::IMAGE_SCN_LNK_COMDAT;
+
+ if (parseCOMDATTypeAndAssoc(Type, Assoc))
+ return true;
+
+ if (getLexer().isNot(AsmToken::Comma))
+ return TokError("expected comma in directive");
+ Lex();
+
+ if (getParser().parseIdentifier(COMDATSymName))
+ return TokError("expected identifier in directive");
+ }
+
if (getLexer().isNot(AsmToken::EndOfStatement))
return TokError("unexpected token in directive");
SectionKind Kind = computeSectionKind(Flags);
- ParseSectionSwitch(SectionName, Flags, Kind);
+ ParseSectionSwitch(SectionName, Flags, Kind, COMDATSymName, Type, Assoc);
return false;
}
@@ -409,37 +444,29 @@
return false;
}
-/// ParseDirectiveLinkOnce
-/// ::= .linkonce [ identifier [ identifier ] ]
-bool COFFAsmParser::ParseDirectiveLinkOnce(StringRef, SMLoc Loc) {
- COFF::COMDATType Type = COFF::IMAGE_COMDAT_SELECT_ANY;
+/// ::= [ identifier [ identifier ] ]
+bool COFFAsmParser::parseCOMDATTypeAndAssoc(COFF::COMDATType &Type,
+ const MCSectionCOFF *&Assoc) {
+ StringRef TypeId = getTok().getIdentifier();
- if (getLexer().is(AsmToken::Identifier)) {
- StringRef TypeId = getTok().getIdentifier();
+ Type = StringSwitch<COFF::COMDATType>(TypeId)
+ .Case("one_only", COFF::IMAGE_COMDAT_SELECT_NODUPLICATES)
+ .Case("discard", COFF::IMAGE_COMDAT_SELECT_ANY)
+ .Case("same_size", COFF::IMAGE_COMDAT_SELECT_SAME_SIZE)
+ .Case("same_contents", COFF::IMAGE_COMDAT_SELECT_EXACT_MATCH)
+ .Case("associative", COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE)
+ .Case("largest", COFF::IMAGE_COMDAT_SELECT_LARGEST)
+ .Case("newest", COFF::IMAGE_COMDAT_SELECT_NEWEST)
+ .Default((COFF::COMDATType)0);
- Type = StringSwitch<COFF::COMDATType>(TypeId)
- .Case("one_only", COFF::IMAGE_COMDAT_SELECT_NODUPLICATES)
- .Case("discard", COFF::IMAGE_COMDAT_SELECT_ANY)
- .Case("same_size", COFF::IMAGE_COMDAT_SELECT_SAME_SIZE)
- .Case("same_contents", COFF::IMAGE_COMDAT_SELECT_EXACT_MATCH)
- .Case("associative", COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE)
- .Case("largest", COFF::IMAGE_COMDAT_SELECT_LARGEST)
- .Case("newest", COFF::IMAGE_COMDAT_SELECT_NEWEST)
- .Default((COFF::COMDATType)0);
+ if (Type == 0)
+ return TokError(Twine("unrecognized COMDAT type '" + TypeId + "'"));
- if (Type == 0)
- return TokError(Twine("unrecognized COMDAT type '" + TypeId + "'"));
+ Lex();
- Lex();
- }
-
- const MCSectionCOFF *Current = static_cast<const MCSectionCOFF*>(
- getStreamer().getCurrentSection().first);
-
- const MCSectionCOFF *Assoc = 0;
if (Type == COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE) {
- StringRef AssocName;
SMLoc Loc = getTok().getLoc();
+ StringRef AssocName;
if (ParseSectionName(AssocName))
return TokError("expected associated section name");
@@ -447,14 +474,33 @@
getContext().getCOFFSection(AssocName));
if (!Assoc)
return Error(Loc, "cannot associate unknown section '" + AssocName + "'");
- if (Assoc == Current)
- return Error(Loc, "cannot associate a section with itself");
if (!(Assoc->getCharacteristics() & COFF::IMAGE_SCN_LNK_COMDAT))
return Error(Loc, "associated section must be a COMDAT section");
if (Assoc->getSelection() == COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE)
return Error(Loc, "associated section cannot be itself associative");
}
+ return false;
+}
+
+/// ParseDirectiveLinkOnce
+/// ::= .linkonce [ identifier [ identifier ] ]
+bool COFFAsmParser::ParseDirectiveLinkOnce(StringRef, SMLoc Loc) {
+ COFF::COMDATType Type = COFF::IMAGE_COMDAT_SELECT_ANY;
+ const MCSectionCOFF *Assoc = 0;
+ if (getLexer().is(AsmToken::Identifier))
+ if (parseCOMDATTypeAndAssoc(Type, Assoc))
+ return true;
+
+ const MCSectionCOFF *Current = static_cast<const MCSectionCOFF*>(
+ getStreamer().getCurrentSection().first);
+
+
+ if (Type == COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE) {
+ if (Assoc == Current)
+ return Error(Loc, "cannot associate a section with itself");
+ }
+
if (Current->getCharacteristics() & COFF::IMAGE_SCN_LNK_COMDAT)
return Error(Loc, Twine("section '") + Current->getSectionName() +
"' is already linkonce");
diff --git a/lib/MC/WinCOFFStreamer.cpp b/lib/MC/WinCOFFStreamer.cpp
index 6744df5..7fc114c 100644
--- a/lib/MC/WinCOFFStreamer.cpp
+++ b/lib/MC/WinCOFFStreamer.cpp
@@ -151,7 +151,8 @@
int Selection = COFF::IMAGE_COMDAT_SELECT_LARGEST;
const MCSection *Section = MCStreamer::getContext().getCOFFSection(
- SectionName, Characteristics, SectionKind::getBSS(), Selection);
+ SectionName, Characteristics, SectionKind::getBSS(), Symbol->getName(),
+ Selection);
MCSectionData &SectionData = getAssembler().getOrCreateSectionData(*Section);
diff --git a/test/MC/COFF/section-comdat.s b/test/MC/COFF/section-comdat.s
new file mode 100644
index 0000000..dd5be87
--- /dev/null
+++ b/test/MC/COFF/section-comdat.s
@@ -0,0 +1,188 @@
+// RUN: llvm-mc -triple i386-pc-win32 -filetype=obj %s | llvm-readobj -s -t | FileCheck %s
+// RUN: llvm-mc -triple x86_64-pc-win32 -filetype=obj %s | llvm-readobj -s -t | FileCheck %s
+
+.section assocSec
+.linkonce
+.long 1
+
+.section secName, "dr", discard, "Symbol1"
+.globl Symbol1
+Symbol1:
+.long 1
+
+.section secName, "dr", one_only, "Symbol2"
+.globl Symbol2
+Symbol2:
+.long 1
+
+.section SecName, "dr", same_size, "Symbol3"
+.globl Symbol3
+Symbol3:
+.long 1
+
+.section SecName, "dr", same_contents, "Symbol4"
+.globl Symbol4
+Symbol4:
+.long 1
+
+.section SecName, "dr", associative assocSec, "Symbol5"
+.globl Symbol5
+Symbol5:
+.long 1
+
+.section SecName, "dr", largest, "Symbol6"
+.globl Symbol6
+Symbol6:
+.long 1
+
+.section SecName, "dr", newest, "Symbol7"
+.globl Symbol7
+Symbol7:
+.long 1
+
+// CHECK: Sections [
+// CHECK: Section {
+// CHECK: Number: 1
+// CHECK: Name: assocSec
+// CHECK: Characteristics [
+// CHECK: IMAGE_SCN_LNK_COMDAT
+// CHECK: ]
+// CHECK: }
+// CHECK: Section {
+// CHECK: Number: 2
+// CHECK: Name: secName
+// CHECK: Characteristics [
+// CHECK: IMAGE_SCN_LNK_COMDAT
+// CHECK: ]
+// CHECK: }
+// CHECK: Section {
+// CHECK: Number: 3
+// CHECK: Name: secName
+// CHECK: Characteristics [
+// CHECK: IMAGE_SCN_LNK_COMDAT
+// CHECK: ]
+// CHECK: }
+// CHECK: Section {
+// CHECK: Number: 4
+// CHECK: Name: SecName
+// CHECK: Characteristics [
+// CHECK: IMAGE_SCN_LNK_COMDAT
+// CHECK: ]
+// CHECK: }
+// CHECK: Section {
+// CHECK: Number: 5
+// CHECK: Name: SecName
+// CHECK: Characteristics [
+// CHECK: IMAGE_SCN_LNK_COMDAT
+// CHECK: ]
+// CHECK: }
+// CHECK: Section {
+// CHECK: Number: 6
+// CHECK: Name: SecName
+// CHECK: Characteristics [
+// CHECK: IMAGE_SCN_LNK_COMDAT
+// CHECK: ]
+// CHECK: }
+// CHECK: Section {
+// CHECK: Number: 7
+// CHECK: Name: SecName
+// CHECK: Characteristics [
+// CHECK: IMAGE_SCN_LNK_COMDAT
+// CHECK: ]
+// CHECK: }
+// CHECK: Section {
+// CHECK: Number: 8
+// CHECK: Name: SecName
+// CHECK: Characteristics [
+// CHECK: IMAGE_SCN_LNK_COMDAT
+// CHECK: ]
+// CHECK: }
+// CHECK: ]
+// CHECK: Symbols [
+// CHECK: Symbol {
+// CHECK: Name: assocSec
+// CHECK: Section: assocSec (1)
+// CHECK: AuxSectionDef {
+// CHECK: Selection: Any
+// CHECK: }
+// CHECK: }
+// CHECK: Symbol {
+// CHECK: Name: secName
+// CHECK: Section: secName (2)
+// CHECK: AuxSectionDef {
+// CHECK: Selection: Any
+// CHECK: }
+// CHECK: }
+// CHECK: Symbol {
+// CHECK: Name: secName
+// CHECK: Section: secName (3)
+// CHECK: AuxSectionDef {
+// CHECK: Selection: NoDuplicates
+// CHECK: }
+// CHECK: }
+// CHECK: Symbol {
+// CHECK: Name: SecName
+// CHECK: Section: SecName (4)
+// CHECK: AuxSectionDef {
+// CHECK: Selection: SameSize
+// CHECK: }
+// CHECK: }
+// CHECK: Symbol {
+// CHECK: Name: SecName
+// CHECK: Section: SecName (5)
+// CHECK: AuxSymbolCount: 1
+// CHECK: AuxSectionDef {
+// CHECK: Selection: ExactMatch
+// CHECK: }
+// CHECK: }
+// CHECK: Symbol {
+// CHECK: Name: SecName
+// CHECK: Section: SecName (6)
+// CHECK: AuxSectionDef {
+// CHECK: Selection: Associative
+// CHECK: AssocSection: assocSec (1)
+// CHECK: }
+// CHECK: }
+// CHECK: Symbol {
+// CHECK: Name: SecName
+// CHECK: Section: SecName (7)
+// CHECK: AuxSectionDef {
+// CHECK: Selection: Largest
+// CHECK: }
+// CHECK: }
+// CHECK: Symbol {
+// CHECK: Name: SecName
+// CHECK: Section: SecName (8)
+// CHECK: AuxSectionDef {
+// CHECK: Selection: Newest (0x7)
+// 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: }
+// CHECK: Symbol {
+// CHECK: Name: Symbol5
+// CHECK: Section: SecName (6)
+// CHECK: }
+// CHECK: Symbol {
+// CHECK: Name: Symbol6
+// CHECK: Section: SecName (7)
+// CHECK: }
+// CHECK: Symbol {
+// CHECK: Name: Symbol7
+// CHECK: Section: SecName (8)
+// CHECK: }
+// CHECK: ]