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.
llvm-svn: 195148
diff --git a/llvm/lib/MC/MCParser/COFFAsmParser.cpp b/llvm/lib/MC/MCParser/COFFAsmParser.cpp
index df1794c..d8343a3 100644
--- a/llvm/lib/MC/MCParser/COFFAsmParser.cpp
+++ b/llvm/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");