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-rw-r--r--lib/Target/TargetLoweringObjectFile.cpp98
1 files changed, 60 insertions, 38 deletions
diff --git a/lib/Target/TargetLoweringObjectFile.cpp b/lib/Target/TargetLoweringObjectFile.cpp
index 70e8008..a231ebc 100644
--- a/lib/Target/TargetLoweringObjectFile.cpp
+++ b/lib/Target/TargetLoweringObjectFile.cpp
@@ -22,11 +22,11 @@
#include "llvm/MC/MCSectionMachO.h"
#include "llvm/MC/MCSectionELF.h"
#include "llvm/MC/MCSymbol.h"
+#include "llvm/Target/Mangler.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Support/ErrorHandling.h"
-#include "llvm/Support/Mangler.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringExtras.h"
@@ -141,9 +141,18 @@ SectionKind TargetLoweringObjectFile::getKindForGlobal(const GlobalValue *GV,
return SectionKind::getThreadData();
}
+ // Variables with common linkage always get classified as common.
+ if (GVar->hasCommonLinkage())
+ return SectionKind::getCommon();
+
// Variable can be easily put to BSS section.
- if (isSuitableForBSS(GVar))
+ if (isSuitableForBSS(GVar)) {
+ if (GVar->hasLocalLinkage())
+ return SectionKind::getBSSLocal();
+ else if (GVar->hasExternalLinkage())
+ return SectionKind::getBSSExtern();
return SectionKind::getBSS();
+ }
Constant *C = GVar->getInitializer();
@@ -300,6 +309,7 @@ getSymbolForDwarfGlobalReference(const GlobalValue *GV, Mangler *Mang,
IsIndirect = false;
IsPCRel = false;
+ // FIXME: Use GetGlobalValueSymbol.
SmallString<128> Name;
Mang->getNameWithPrefix(Name, GV, false);
return MCSymbolRefExpr::Create(Name.str(), getContext());
@@ -464,30 +474,30 @@ void TargetLoweringObjectFileELF::Initialize(MCContext &Ctx,
static SectionKind
-getELFKindForNamedSection(const char *Name, SectionKind K) {
- if (Name[0] != '.') return K;
+getELFKindForNamedSection(StringRef Name, SectionKind K) {
+ if (Name.empty() || Name[0] != '.') return K;
// Some lame default implementation based on some magic section names.
- if (strcmp(Name, ".bss") == 0 ||
- strncmp(Name, ".bss.", 5) == 0 ||
- strncmp(Name, ".gnu.linkonce.b.", 16) == 0 ||
- strncmp(Name, ".llvm.linkonce.b.", 17) == 0 ||
- strcmp(Name, ".sbss") == 0 ||
- strncmp(Name, ".sbss.", 6) == 0 ||
- strncmp(Name, ".gnu.linkonce.sb.", 17) == 0 ||
- strncmp(Name, ".llvm.linkonce.sb.", 18) == 0)
+ if (Name == ".bss" ||
+ Name.startswith(".bss.") ||
+ Name.startswith(".gnu.linkonce.b.") ||
+ Name.startswith(".llvm.linkonce.b.") ||
+ Name == ".sbss" ||
+ Name.startswith(".sbss.") ||
+ Name.startswith(".gnu.linkonce.sb.") ||
+ Name.startswith(".llvm.linkonce.sb."))
return SectionKind::getBSS();
- if (strcmp(Name, ".tdata") == 0 ||
- strncmp(Name, ".tdata.", 7) == 0 ||
- strncmp(Name, ".gnu.linkonce.td.", 17) == 0 ||
- strncmp(Name, ".llvm.linkonce.td.", 18) == 0)
+ if (Name == ".tdata" ||
+ Name.startswith(".tdata.") ||
+ Name.startswith(".gnu.linkonce.td.") ||
+ Name.startswith(".llvm.linkonce.td."))
return SectionKind::getThreadData();
- if (strcmp(Name, ".tbss") == 0 ||
- strncmp(Name, ".tbss.", 6) == 0 ||
- strncmp(Name, ".gnu.linkonce.tb.", 17) == 0 ||
- strncmp(Name, ".llvm.linkonce.tb.", 18) == 0)
+ if (Name == ".tbss" ||
+ Name.startswith(".tbss.") ||
+ Name.startswith(".gnu.linkonce.tb.") ||
+ Name.startswith(".llvm.linkonce.tb."))
return SectionKind::getThreadBSS();
return K;
@@ -543,7 +553,7 @@ getELFSectionFlags(SectionKind K) {
const MCSection *TargetLoweringObjectFileELF::
getExplicitSectionGlobal(const GlobalValue *GV, SectionKind Kind,
Mangler *Mang, const TargetMachine &TM) const {
- const char *SectionName = GV->getSection().c_str();
+ StringRef SectionName = GV->getSection();
// Infer section flags from the section name if we can.
Kind = getELFKindForNamedSection(SectionName, Kind);
@@ -560,7 +570,6 @@ static const char *getSectionPrefixForUniqueGlobal(SectionKind Kind) {
if (Kind.isThreadData()) return ".gnu.linkonce.td.";
if (Kind.isThreadBSS()) return ".gnu.linkonce.tb.";
- if (Kind.isBSS()) return ".gnu.linkonce.b.";
if (Kind.isDataNoRel()) return ".gnu.linkonce.d.";
if (Kind.isDataRelLocal()) return ".gnu.linkonce.d.rel.local.";
if (Kind.isDataRel()) return ".gnu.linkonce.d.rel.";
@@ -576,20 +585,13 @@ 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()) {
+ if (GV->isWeakForLinker() && !Kind.isCommon() && !Kind.isBSS()) {
const char *Prefix = getSectionPrefixForUniqueGlobal(Kind);
- SmallString<128> Name, MangledName;
+ SmallString<128> Name;
Name.append(Prefix, Prefix+strlen(Prefix));
Mang->getNameWithPrefix(Name, GV, false);
-
- raw_svector_ostream OS(MangledName);
- MCSymbol::printMangledName(Name, OS, 0);
- OS.flush();
-
- return getELFSection(MangledName.str(),
- getELFSectionType(MangledName.str(), Kind),
- getELFSectionFlags(Kind),
- Kind);
+ return getELFSection(Name.str(), getELFSectionType(Name.str(), Kind),
+ getELFSectionFlags(Kind), Kind);
}
if (Kind.isText()) return TextSection;
@@ -614,7 +616,7 @@ SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
std::string Name = SizeSpec + utostr(Align);
- return getELFSection(Name.c_str(), MCSectionELF::SHT_PROGBITS,
+ return getELFSection(Name, MCSectionELF::SHT_PROGBITS,
MCSectionELF::SHF_ALLOC |
MCSectionELF::SHF_MERGE |
MCSectionELF::SHF_STRINGS,
@@ -636,7 +638,10 @@ SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
if (Kind.isThreadData()) return TLSDataSection;
if (Kind.isThreadBSS()) return TLSBSSSection;
- if (Kind.isBSS()) return BSSSection;
+ // Note: we claim that common symbols are put in BSSSection, but they are
+ // really emitted with the magic .comm directive, which creates a symbol table
+ // entry but not a section.
+ if (Kind.isBSS() || Kind.isCommon()) return BSSSection;
if (Kind.isDataNoRel()) return DataSection;
if (Kind.isDataRelLocal()) return DataRelLocalSection;
@@ -762,7 +767,13 @@ void TargetLoweringObjectFileMachO::Initialize(MCContext &Ctx,
DataCoalSection
= getMachOSection("__DATA","__datacoal_nt", MCSectionMachO::S_COALESCED,
SectionKind::getDataRel());
-
+ DataCommonSection
+ = getMachOSection("__DATA","__common", MCSectionMachO::S_ZEROFILL,
+ SectionKind::getBSS());
+ DataBSSSection
+ = getMachOSection("__DATA","__bss", MCSectionMachO::S_ZEROFILL,
+ SectionKind::getBSS());
+
LazySymbolPointerSection
= getMachOSection("__DATA", "__la_symbol_ptr",
@@ -921,6 +932,16 @@ SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
if (Kind.isReadOnlyWithRel())
return ConstDataSection;
+ // Put zero initialized globals with strong external linkage in the
+ // DATA, __common section with the .zerofill directive.
+ if (Kind.isBSSExtern())
+ return DataCommonSection;
+
+ // Put zero initialized globals with local linkage in __DATA,__bss directive
+ // with the .zerofill directive (aka .lcomm).
+ if (Kind.isBSSLocal())
+ return DataBSSSection;
+
// Otherwise, just drop the variable in the normal data section.
return DataSection;
}
@@ -955,7 +976,8 @@ shouldEmitUsedDirectiveFor(const GlobalValue *GV, Mangler *Mang) const {
// FIXME: ObjC metadata is currently emitted as internal symbols that have
// \1L and \0l prefixes on them. Fix them to be Private/LinkerPrivate and
// this horrible hack can go away.
- const std::string &Name = Mang->getMangledName(GV);
+ SmallString<64> Name;
+ Mang->getNameWithPrefix(Name, GV, false);
if (Name[0] == 'L' || Name[0] == 'l')
return false;
}
@@ -1064,7 +1086,7 @@ void TargetLoweringObjectFileCOFF::Initialize(MCContext &Ctx,
const MCSection *TargetLoweringObjectFileCOFF::
getExplicitSectionGlobal(const GlobalValue *GV, SectionKind Kind,
Mangler *Mang, const TargetMachine &TM) const {
- return getCOFFSection(GV->getSection().c_str(), false, Kind);
+ return getCOFFSection(GV->getSection(), false, Kind);
}
static const char *getCOFFSectionPrefixForUniqueGlobal(SectionKind Kind) {
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