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//===-- DarwinTargetAsmInfo.cpp - Darwin 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 Darwin-based targets
//
//===----------------------------------------------------------------------===//
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
#include "llvm/GlobalVariable.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/Mangler.h"
#include "llvm/Target/DarwinTargetAsmInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetData.h"
using namespace llvm;
DarwinTargetAsmInfo::DarwinTargetAsmInfo(const TargetMachine &TM)
: TargetAsmInfo(TM) {
CStringSection_ = getUnnamedSection("\t.cstring",
SectionFlags::Mergeable |SectionFlags::Strings);
FourByteConstantSection = getUnnamedSection("\t.literal4\n",
SectionFlags::Mergeable);
EightByteConstantSection = getUnnamedSection("\t.literal8\n",
SectionFlags::Mergeable);
// Note: 16-byte constant section is subtarget specific and should be provided
// there, if needed.
SixteenByteConstantSection = 0;
ReadOnlySection = getUnnamedSection("\t.const\n", SectionFlags::None);
TextCoalSection =
getNamedSection("\t__TEXT,__textcoal_nt,coalesced,pure_instructions",
SectionFlags::Code);
ConstTextCoalSection = getNamedSection("\t__TEXT,__const_coal,coalesced",
SectionFlags::None);
ConstDataCoalSection = getNamedSection("\t__DATA,__const_coal,coalesced",
SectionFlags::None);
ConstDataSection = getUnnamedSection(".const_data", SectionFlags::None);
DataCoalSection = getNamedSection("\t__DATA,__datacoal_nt,coalesced",
SectionFlags::Writeable);
// Common settings for all Darwin targets.
// Syntax:
GlobalPrefix = "_";
PrivateGlobalPrefix = "L";
LinkerPrivateGlobalPrefix = "l"; // Marker for some ObjC metadata
NeedsSet = true;
NeedsIndirectEncoding = true;
AllowQuotesInName = true;
HasSingleParameterDotFile = false;
// In non-PIC modes, emit a special label before jump tables so that the
// linker can perform more accurate dead code stripping. We do not check the
// relocation model here since it can be overridden later.
JumpTableSpecialLabelPrefix = "l";
// Directives:
WeakDefDirective = "\t.weak_definition ";
WeakRefDirective = "\t.weak_reference ";
HiddenDirective = "\t.private_extern ";
// Sections:
CStringSection = "\t.cstring";
JumpTableDataSection = "\t.const\n";
BSSSection = 0;
if (TM.getRelocationModel() == Reloc::Static) {
StaticCtorsSection = ".constructor";
StaticDtorsSection = ".destructor";
} else {
StaticCtorsSection = ".mod_init_func";
StaticDtorsSection = ".mod_term_func";
}
// _foo.eh symbols are currently always exported so that the linker knows
// about them. This may not strictly be necessary on 10.6 and later, but it
// doesn't hurt anything.
Is_EHSymbolPrivate = false;
DwarfAbbrevSection = ".section __DWARF,__debug_abbrev,regular,debug";
DwarfInfoSection = ".section __DWARF,__debug_info,regular,debug";
DwarfLineSection = ".section __DWARF,__debug_line,regular,debug";
DwarfFrameSection = ".section __DWARF,__debug_frame,regular,debug";
DwarfPubNamesSection = ".section __DWARF,__debug_pubnames,regular,debug";
DwarfPubTypesSection = ".section __DWARF,__debug_pubtypes,regular,debug";
DwarfStrSection = ".section __DWARF,__debug_str,regular,debug";
DwarfLocSection = ".section __DWARF,__debug_loc,regular,debug";
DwarfARangesSection = ".section __DWARF,__debug_aranges,regular,debug";
DwarfRangesSection = ".section __DWARF,__debug_ranges,regular,debug";
DwarfMacroInfoSection = ".section __DWARF,__debug_macinfo,regular,debug";
}
/// emitUsedDirectiveFor - On Darwin, internally linked data beginning with
/// the PrivateGlobalPrefix or the LinkerPrivateGlobalPrefix does not have the
/// directive emitted (this occurs in ObjC metadata).
bool DarwinTargetAsmInfo::emitUsedDirectiveFor(const GlobalValue* GV,
Mangler *Mang) const {
if (!GV) return false;
// Check whether the mangled name has the "Private" or "LinkerPrivate" prefix.
if (GV->hasLocalLinkage() && !isa<Function>(GV)) {
// 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);
if (Name[0] == 'L' || Name[0] == 'l')
return false;
}
return true;
}
const Section*
DarwinTargetAsmInfo::SelectSectionForGlobal(const GlobalValue *GV,
SectionKind::Kind Kind) const {
bool isWeak = GV->isWeakForLinker();
bool isNonStatic = TM.getRelocationModel() != Reloc::Static;
switch (Kind) {
case SectionKind::ThreadData:
case SectionKind::ThreadBSS:
llvm_unreachable("Darwin doesn't support TLS");
case SectionKind::Text:
if (isWeak)
return TextCoalSection;
return TextSection;
case SectionKind::Data:
case SectionKind::DataRelLocal:
case SectionKind::DataRel:
case SectionKind::BSS:
if (cast<GlobalVariable>(GV)->isConstant())
return isWeak ? ConstDataCoalSection : ConstDataSection;
return isWeak ? DataCoalSection : DataSection;
case SectionKind::ROData:
case SectionKind::DataRelRO:
case SectionKind::DataRelROLocal:
return (isWeak ? ConstDataCoalSection :
(isNonStatic ? ConstDataSection : getReadOnlySection()));
case SectionKind::RODataMergeStr:
return (isWeak ?
ConstTextCoalSection :
MergeableStringSection(cast<GlobalVariable>(GV)));
case SectionKind::RODataMergeConst: {
if (isWeak) return ConstDataCoalSection;
const Type *Ty = cast<GlobalVariable>(GV)->getInitializer()->getType();
const TargetData *TD = TM.getTargetData();
return getSectionForMergableConstant(TD->getTypeAllocSize(Ty), 0);
}
default:
llvm_unreachable("Unsuported section kind for global");
}
// FIXME: Do we have any extra special weird cases?
return NULL;
}
const Section*
DarwinTargetAsmInfo::MergeableStringSection(const GlobalVariable *GV) const {
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) {
unsigned Align = TD->getPreferredAlignment(GV);
if (Align <= 32)
return getCStringSection_();
}
return getReadOnlySection();
}
const Section *
DarwinTargetAsmInfo::getSectionForMergableConstant(uint64_t Size,
unsigned ReloInfo) const {
// If this constant requires a relocation, we have to put it in the data
// segment, not in the text segment.
if (ReloInfo != 0)
return ConstDataSection;
switch (Size) {
default: break;
case 4:
return FourByteConstantSection;
case 8:
return EightByteConstantSection;
case 16:
if (SixteenByteConstantSection)
return SixteenByteConstantSection;
break;
}
return ReadOnlySection; // .const
}
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