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//===-- ELFTargetAsmInfo.cpp - ELF asm properties ---------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines target asm properties related what form asm statements
// should take in general on ELF-based targets
//
//===----------------------------------------------------------------------===//
#include "llvm/Target/ELFTargetAsmInfo.h"
#include "llvm/ADT/SmallVector.h"
using namespace llvm;
ELFTargetAsmInfo::ELFTargetAsmInfo(const TargetMachine &TM)
: TargetAsmInfo(TM) {
TextSection = getOrCreateSection("\t.text", true, SectionKind::Text);
DataSection = getOrCreateSection("\t.data", true, SectionKind::DataRel);
ReadOnlySection =
getOrCreateSection("\t.rodata", false, SectionKind::ReadOnly);
TLSDataSection =
getOrCreateSection("\t.tdata", false, SectionKind::ThreadData);
TLSBSSSection = getOrCreateSection("\t.tbss", false, SectionKind::ThreadBSS);
DataRelSection = getOrCreateSection("\t.data.rel", false,
SectionKind::DataRel);
DataRelLocalSection = getOrCreateSection("\t.data.rel.local", false,
SectionKind::DataRelLocal);
DataRelROSection = getOrCreateSection("\t.data.rel.ro", false,
SectionKind::ReadOnlyWithRel);
DataRelROLocalSection =
getOrCreateSection("\t.data.rel.ro.local", false,
SectionKind::ReadOnlyWithRelLocal);
MergeableConst4Section = getOrCreateSection(".rodata.cst4", false,
SectionKind::MergeableConst4);
MergeableConst8Section = getOrCreateSection(".rodata.cst8", false,
SectionKind::MergeableConst8);
MergeableConst16Section = getOrCreateSection(".rodata.cst16", false,
SectionKind::MergeableConst16);
}
/// getFlagsForNamedSection - If this target wants to be able to infer
/// section flags based on the name of the section specified for a global
/// variable, it can implement this.
SectionKind::Kind ELFTargetAsmInfo::getKindForNamedSection(const char *Name,
SectionKind::Kind K) const {
if (Name[0] != '.') return K;
// Some lame default implementation based on some magic section names.
if (strncmp(Name, ".gnu.linkonce.b.", 16) == 0 ||
strncmp(Name, ".llvm.linkonce.b.", 17) == 0 ||
strncmp(Name, ".gnu.linkonce.sb.", 17) == 0 ||
strncmp(Name, ".llvm.linkonce.sb.", 18) == 0)
return SectionKind::BSS;
if (strcmp(Name, ".tdata") == 0 ||
strncmp(Name, ".tdata.", 7) == 0 ||
strncmp(Name, ".gnu.linkonce.td.", 17) == 0 ||
strncmp(Name, ".llvm.linkonce.td.", 18) == 0)
return SectionKind::ThreadData;
if (strcmp(Name, ".tbss") == 0 ||
strncmp(Name, ".tbss.", 6) == 0 ||
strncmp(Name, ".gnu.linkonce.tb.", 17) == 0 ||
strncmp(Name, ".llvm.linkonce.tb.", 18) == 0)
return SectionKind::ThreadBSS;
return K;
}
void ELFTargetAsmInfo::getSectionFlagsAsString(SectionKind Kind,
SmallVectorImpl<char> &Str) const {
Str.push_back(',');
Str.push_back('"');
if (!Kind.isMetadata())
Str.push_back('a');
if (Kind.isText())
Str.push_back('x');
if (Kind.isWriteable())
Str.push_back('w');
if (Kind.isMergeableConst() || Kind.isMergeableCString())
Str.push_back('M');
if (Kind.isMergeableCString())
Str.push_back('S');
if (Kind.isThreadLocal())
Str.push_back('T');
Str.push_back('"');
Str.push_back(',');
// If comment string is '@', e.g. as on ARM - use '%' instead
if (strcmp(CommentString, "@") == 0)
Str.push_back('%');
else
Str.push_back('@');
const char *KindStr;
if (Kind.isBSS())
KindStr = "nobits";
else
KindStr = "progbits";
Str.append(KindStr, KindStr+strlen(KindStr));
if (Kind.isMergeableCString()) {
// TODO: Eventually handle multiple byte character strings. For now, all
// mergable C strings are single byte.
Str.push_back(',');
Str.push_back('1');
} else if (Kind.isMergeableConst4()) {
Str.push_back(',');
Str.push_back('4');
} else if (Kind.isMergeableConst8()) {
Str.push_back(',');
Str.push_back('8');
} else if (Kind.isMergeableConst16()) {
Str.push_back(',');
Str.push_back('1');
Str.push_back('6');
}
}
//===----------------------------------------------------------------------===//
// Move to AsmPrinter (mangler access).
//===----------------------------------------------------------------------===//
#include "llvm/DerivedTypes.h"
#include "llvm/GlobalVariable.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/ADT/StringExtras.h"
static const char *getSectionPrefixForUniqueGlobal(SectionKind Kind) {
if (Kind.isText()) return ".gnu.linkonce.t.";
if (Kind.isReadOnly()) return ".gnu.linkonce.r.";
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.";
if (Kind.isReadOnlyWithRelLocal()) return ".gnu.linkonce.d.rel.ro.local.";
assert(Kind.isReadOnlyWithRel() && "Unknown section kind");
return ".gnu.linkonce.d.rel.ro.";
}
const Section*
ELFTargetAsmInfo::SelectSectionForGlobal(const GlobalValue *GV,
SectionKind Kind) const {
// 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 (Kind.isWeak()) {
const char *Prefix = getSectionPrefixForUniqueGlobal(Kind);
// FIXME: Use mangler interface (PR4584).
std::string Name = Prefix+GV->getNameStr();
return getOrCreateSection(Name.c_str(), false, Kind.getKind());
}
if (Kind.isText()) return TextSection;
if (Kind.isMergeableCString()) {
const TargetData *TD = TM.getTargetData();
Constant *C = cast<GlobalVariable>(GV)->getInitializer();
const Type *Ty = cast<ArrayType>(C->getType())->getElementType();
unsigned Size = TD->getTypeAllocSize(Ty);
if (Size <= 16) {
assert(getCStringSection() && "Should have string section prefix");
// We also need alignment here.
// FIXME: this is getting the alignment of the character, not the
// alignment of the string!!
unsigned Align = TD->getPrefTypeAlignment(Ty);
if (Align < Size)
Align = Size;
std::string Name = getCStringSection() + utostr(Size) + '.' +
utostr(Align);
return getOrCreateSection(Name.c_str(), false,
SectionKind::MergeableCString);
}
return getReadOnlySection();
}
if (Kind.isMergeableConst()) {
if (Kind.isMergeableConst4())
return MergeableConst4Section;
if (Kind.isMergeableConst8())
return MergeableConst8Section;
if (Kind.isMergeableConst16())
return MergeableConst16Section;
return ReadOnlySection; // .const
}
if (Kind.isReadOnly()) return getReadOnlySection();
if (Kind.isThreadData()) return TLSDataSection;
if (Kind.isThreadBSS()) return TLSBSSSection;
if (Kind.isBSS()) return getBSSSection_();
if (Kind.isDataNoRel()) return DataSection;
if (Kind.isDataRelLocal()) return DataRelLocalSection;
if (Kind.isDataRel()) return DataRelSection;
if (Kind.isReadOnlyWithRelLocal()) return DataRelROLocalSection;
assert(Kind.isReadOnlyWithRel() && "Unknown section kind");
return DataRelROSection;
}
/// getSectionForMergeableConstant - Given a Mergeable constant with the
/// specified size and relocation information, return a section that it
/// should be placed in.
const Section *
ELFTargetAsmInfo::getSectionForMergeableConstant(SectionKind Kind) const {
return SelectSectionForGlobal(0, Kind);
}
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