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llvm-mirror/lib/MC/MCObjectFileInfo.cpp
Rafael Espindola 2c21fe4650 Stop producing .data.rel sections.
If a section is rw, it is irrelevant if the dynamic linker will write to
it or not.

It looks like llvm implemented this because gcc was doing it. It looks
like gcc implemented this in the hope that it would put all the
relocated items close together and speed up the dynamic linker.

There are two problem with this:
* It doesn't work. Both bfd and gold will map .data.rel to .data and
  concatenate the input sections in the order they are seen.
* If we want a feature like that, it can be implemented directly in the
  linker since it knowns where the dynamic relocations are.

llvm-svn: 253436
2015-11-18 06:02:15 +00:00

823 lines
34 KiB
C++

//===-- MObjectFileInfo.cpp - Object File Information ---------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/MC/MCObjectFileInfo.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/Triple.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCSectionCOFF.h"
#include "llvm/MC/MCSectionELF.h"
#include "llvm/MC/MCSectionMachO.h"
#include "llvm/Support/COFF.h"
using namespace llvm;
static bool useCompactUnwind(const Triple &T) {
// Only on darwin.
if (!T.isOSDarwin())
return false;
// aarch64 always has it.
if (T.getArch() == Triple::aarch64)
return true;
// armv7k always has it.
if (T.isWatchOS())
return true;
// Use it on newer version of OS X.
if (T.isMacOSX() && !T.isMacOSXVersionLT(10, 6))
return true;
// And the iOS simulator.
if (T.isiOS() &&
(T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86))
return true;
return false;
}
void MCObjectFileInfo::initMachOMCObjectFileInfo(Triple T) {
// MachO
SupportsWeakOmittedEHFrame = false;
EHFrameSection = Ctx->getMachOSection(
"__TEXT", "__eh_frame",
MachO::S_COALESCED | MachO::S_ATTR_NO_TOC |
MachO::S_ATTR_STRIP_STATIC_SYMS | MachO::S_ATTR_LIVE_SUPPORT,
SectionKind::getReadOnly());
if (T.isOSDarwin() && T.getArch() == Triple::aarch64)
SupportsCompactUnwindWithoutEHFrame = true;
if (T.isWatchOS())
OmitDwarfIfHaveCompactUnwind = true;
PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel
| dwarf::DW_EH_PE_sdata4;
LSDAEncoding = FDECFIEncoding = dwarf::DW_EH_PE_pcrel;
TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
dwarf::DW_EH_PE_sdata4;
// .comm doesn't support alignment before Leopard.
if (T.isMacOSX() && T.isMacOSXVersionLT(10, 5))
CommDirectiveSupportsAlignment = false;
TextSection // .text
= Ctx->getMachOSection("__TEXT", "__text",
MachO::S_ATTR_PURE_INSTRUCTIONS,
SectionKind::getText());
DataSection // .data
= Ctx->getMachOSection("__DATA", "__data", 0, SectionKind::getData());
// BSSSection might not be expected initialized on msvc.
BSSSection = nullptr;
TLSDataSection // .tdata
= Ctx->getMachOSection("__DATA", "__thread_data",
MachO::S_THREAD_LOCAL_REGULAR,
SectionKind::getData());
TLSBSSSection // .tbss
= Ctx->getMachOSection("__DATA", "__thread_bss",
MachO::S_THREAD_LOCAL_ZEROFILL,
SectionKind::getThreadBSS());
// TODO: Verify datarel below.
TLSTLVSection // .tlv
= Ctx->getMachOSection("__DATA", "__thread_vars",
MachO::S_THREAD_LOCAL_VARIABLES,
SectionKind::getData());
TLSThreadInitSection = Ctx->getMachOSection(
"__DATA", "__thread_init", MachO::S_THREAD_LOCAL_INIT_FUNCTION_POINTERS,
SectionKind::getData());
CStringSection // .cstring
= Ctx->getMachOSection("__TEXT", "__cstring",
MachO::S_CSTRING_LITERALS,
SectionKind::getMergeable1ByteCString());
UStringSection
= Ctx->getMachOSection("__TEXT","__ustring", 0,
SectionKind::getMergeable2ByteCString());
FourByteConstantSection // .literal4
= Ctx->getMachOSection("__TEXT", "__literal4",
MachO::S_4BYTE_LITERALS,
SectionKind::getMergeableConst4());
EightByteConstantSection // .literal8
= Ctx->getMachOSection("__TEXT", "__literal8",
MachO::S_8BYTE_LITERALS,
SectionKind::getMergeableConst8());
SixteenByteConstantSection // .literal16
= Ctx->getMachOSection("__TEXT", "__literal16",
MachO::S_16BYTE_LITERALS,
SectionKind::getMergeableConst16());
ReadOnlySection // .const
= Ctx->getMachOSection("__TEXT", "__const", 0,
SectionKind::getReadOnly());
// If the target is not powerpc, map the coal sections to the non-coal
// sections.
//
// "__TEXT/__textcoal_nt" => section "__TEXT/__text"
// "__TEXT/__const_coal" => section "__TEXT/__const"
// "__DATA/__datacoal_nt" => section "__DATA/__data"
Triple::ArchType ArchTy = T.getArch();
if (ArchTy == Triple::ppc || ArchTy == Triple::ppc64) {
TextCoalSection
= Ctx->getMachOSection("__TEXT", "__textcoal_nt",
MachO::S_COALESCED |
MachO::S_ATTR_PURE_INSTRUCTIONS,
SectionKind::getText());
ConstTextCoalSection
= Ctx->getMachOSection("__TEXT", "__const_coal",
MachO::S_COALESCED,
SectionKind::getReadOnly());
DataCoalSection = Ctx->getMachOSection(
"__DATA", "__datacoal_nt", MachO::S_COALESCED, SectionKind::getData());
} else {
TextCoalSection = TextSection;
ConstTextCoalSection = ReadOnlySection;
DataCoalSection = DataSection;
}
ConstDataSection // .const_data
= Ctx->getMachOSection("__DATA", "__const", 0,
SectionKind::getReadOnlyWithRel());
DataCommonSection
= Ctx->getMachOSection("__DATA","__common",
MachO::S_ZEROFILL,
SectionKind::getBSS());
DataBSSSection
= Ctx->getMachOSection("__DATA","__bss", MachO::S_ZEROFILL,
SectionKind::getBSS());
LazySymbolPointerSection
= Ctx->getMachOSection("__DATA", "__la_symbol_ptr",
MachO::S_LAZY_SYMBOL_POINTERS,
SectionKind::getMetadata());
NonLazySymbolPointerSection
= Ctx->getMachOSection("__DATA", "__nl_symbol_ptr",
MachO::S_NON_LAZY_SYMBOL_POINTERS,
SectionKind::getMetadata());
if (RelocM == Reloc::Static) {
StaticCtorSection = Ctx->getMachOSection("__TEXT", "__constructor", 0,
SectionKind::getData());
StaticDtorSection = Ctx->getMachOSection("__TEXT", "__destructor", 0,
SectionKind::getData());
} else {
StaticCtorSection = Ctx->getMachOSection("__DATA", "__mod_init_func",
MachO::S_MOD_INIT_FUNC_POINTERS,
SectionKind::getData());
StaticDtorSection = Ctx->getMachOSection("__DATA", "__mod_term_func",
MachO::S_MOD_TERM_FUNC_POINTERS,
SectionKind::getData());
}
// Exception Handling.
LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0,
SectionKind::getReadOnlyWithRel());
COFFDebugSymbolsSection = nullptr;
if (useCompactUnwind(T)) {
CompactUnwindSection =
Ctx->getMachOSection("__LD", "__compact_unwind", MachO::S_ATTR_DEBUG,
SectionKind::getReadOnly());
if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86)
CompactUnwindDwarfEHFrameOnly = 0x04000000; // UNWIND_X86_64_MODE_DWARF
else if (T.getArch() == Triple::aarch64)
CompactUnwindDwarfEHFrameOnly = 0x03000000; // UNWIND_ARM64_MODE_DWARF
else if (T.getArch() == Triple::arm || T.getArch() == Triple::thumb)
CompactUnwindDwarfEHFrameOnly = 0x04000000; // UNWIND_ARM_MODE_DWARF
}
// Debug Information.
DwarfAccelNamesSection =
Ctx->getMachOSection("__DWARF", "__apple_names", MachO::S_ATTR_DEBUG,
SectionKind::getMetadata(), "names_begin");
DwarfAccelObjCSection =
Ctx->getMachOSection("__DWARF", "__apple_objc", MachO::S_ATTR_DEBUG,
SectionKind::getMetadata(), "objc_begin");
// 16 character section limit...
DwarfAccelNamespaceSection =
Ctx->getMachOSection("__DWARF", "__apple_namespac", MachO::S_ATTR_DEBUG,
SectionKind::getMetadata(), "namespac_begin");
DwarfAccelTypesSection =
Ctx->getMachOSection("__DWARF", "__apple_types", MachO::S_ATTR_DEBUG,
SectionKind::getMetadata(), "types_begin");
DwarfAbbrevSection =
Ctx->getMachOSection("__DWARF", "__debug_abbrev", MachO::S_ATTR_DEBUG,
SectionKind::getMetadata(), "section_abbrev");
DwarfInfoSection =
Ctx->getMachOSection("__DWARF", "__debug_info", MachO::S_ATTR_DEBUG,
SectionKind::getMetadata(), "section_info");
DwarfLineSection =
Ctx->getMachOSection("__DWARF", "__debug_line", MachO::S_ATTR_DEBUG,
SectionKind::getMetadata(), "section_line");
DwarfFrameSection =
Ctx->getMachOSection("__DWARF", "__debug_frame", MachO::S_ATTR_DEBUG,
SectionKind::getMetadata());
DwarfPubNamesSection =
Ctx->getMachOSection("__DWARF", "__debug_pubnames", MachO::S_ATTR_DEBUG,
SectionKind::getMetadata());
DwarfPubTypesSection =
Ctx->getMachOSection("__DWARF", "__debug_pubtypes", MachO::S_ATTR_DEBUG,
SectionKind::getMetadata());
DwarfGnuPubNamesSection =
Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn", MachO::S_ATTR_DEBUG,
SectionKind::getMetadata());
DwarfGnuPubTypesSection =
Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt", MachO::S_ATTR_DEBUG,
SectionKind::getMetadata());
DwarfStrSection =
Ctx->getMachOSection("__DWARF", "__debug_str", MachO::S_ATTR_DEBUG,
SectionKind::getMetadata(), "info_string");
DwarfLocSection =
Ctx->getMachOSection("__DWARF", "__debug_loc", MachO::S_ATTR_DEBUG,
SectionKind::getMetadata(), "section_debug_loc");
DwarfARangesSection =
Ctx->getMachOSection("__DWARF", "__debug_aranges", MachO::S_ATTR_DEBUG,
SectionKind::getMetadata());
DwarfRangesSection =
Ctx->getMachOSection("__DWARF", "__debug_ranges", MachO::S_ATTR_DEBUG,
SectionKind::getMetadata(), "debug_range");
DwarfDebugInlineSection =
Ctx->getMachOSection("__DWARF", "__debug_inlined", MachO::S_ATTR_DEBUG,
SectionKind::getMetadata());
StackMapSection = Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps",
0, SectionKind::getMetadata());
FaultMapSection = Ctx->getMachOSection("__LLVM_FAULTMAPS", "__llvm_faultmaps",
0, SectionKind::getMetadata());
TLSExtraDataSection = TLSTLVSection;
}
void MCObjectFileInfo::initELFMCObjectFileInfo(Triple T) {
switch (T.getArch()) {
case Triple::mips:
case Triple::mipsel:
FDECFIEncoding = dwarf::DW_EH_PE_sdata4;
break;
case Triple::mips64:
case Triple::mips64el:
FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
break;
case Triple::x86_64:
FDECFIEncoding = dwarf::DW_EH_PE_pcrel |
((CMModel == CodeModel::Large) ? dwarf::DW_EH_PE_sdata8
: dwarf::DW_EH_PE_sdata4);
break;
default:
FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
break;
}
switch (T.getArch()) {
case Triple::arm:
case Triple::armeb:
case Triple::thumb:
case Triple::thumbeb:
if (Ctx->getAsmInfo()->getExceptionHandlingType() == ExceptionHandling::ARM)
break;
// Fallthrough if not using EHABI
case Triple::ppc:
case Triple::x86:
PersonalityEncoding = (RelocM == Reloc::PIC_)
? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
: dwarf::DW_EH_PE_absptr;
LSDAEncoding = (RelocM == Reloc::PIC_)
? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
: dwarf::DW_EH_PE_absptr;
TTypeEncoding = (RelocM == Reloc::PIC_)
? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
: dwarf::DW_EH_PE_absptr;
break;
case Triple::x86_64:
if (RelocM == Reloc::PIC_) {
PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
LSDAEncoding = dwarf::DW_EH_PE_pcrel |
(CMModel == CodeModel::Small
? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
} else {
PersonalityEncoding =
(CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
LSDAEncoding = (CMModel == CodeModel::Small)
? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
TTypeEncoding = (CMModel == CodeModel::Small)
? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
}
break;
case Triple::aarch64:
case Triple::aarch64_be:
// The small model guarantees static code/data size < 4GB, but not where it
// will be in memory. Most of these could end up >2GB away so even a signed
// pc-relative 32-bit address is insufficient, theoretically.
if (RelocM == Reloc::PIC_) {
PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
dwarf::DW_EH_PE_sdata8;
LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8;
TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
dwarf::DW_EH_PE_sdata8;
} else {
PersonalityEncoding = dwarf::DW_EH_PE_absptr;
LSDAEncoding = dwarf::DW_EH_PE_absptr;
TTypeEncoding = dwarf::DW_EH_PE_absptr;
}
break;
case Triple::mips:
case Triple::mipsel:
case Triple::mips64:
case Triple::mips64el:
// MIPS uses indirect pointer to refer personality functions and types, so
// that the eh_frame section can be read-only. DW.ref.personality will be
// generated for relocation.
PersonalityEncoding = dwarf::DW_EH_PE_indirect;
// FIXME: The N64 ABI probably ought to use DW_EH_PE_sdata8 but we can't
// identify N64 from just a triple.
TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
dwarf::DW_EH_PE_sdata4;
// We don't support PC-relative LSDA references in GAS so we use the default
// DW_EH_PE_absptr for those.
break;
case Triple::ppc64:
case Triple::ppc64le:
PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
dwarf::DW_EH_PE_udata8;
LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
dwarf::DW_EH_PE_udata8;
break;
case Triple::sparcel:
case Triple::sparc:
if (RelocM == Reloc::PIC_) {
LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
dwarf::DW_EH_PE_sdata4;
TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
dwarf::DW_EH_PE_sdata4;
} else {
LSDAEncoding = dwarf::DW_EH_PE_absptr;
PersonalityEncoding = dwarf::DW_EH_PE_absptr;
TTypeEncoding = dwarf::DW_EH_PE_absptr;
}
break;
case Triple::sparcv9:
LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
if (RelocM == Reloc::PIC_) {
PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
dwarf::DW_EH_PE_sdata4;
TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
dwarf::DW_EH_PE_sdata4;
} else {
PersonalityEncoding = dwarf::DW_EH_PE_absptr;
TTypeEncoding = dwarf::DW_EH_PE_absptr;
}
break;
case Triple::systemz:
// All currently-defined code models guarantee that 4-byte PC-relative
// values will be in range.
if (RelocM == Reloc::PIC_) {
PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
dwarf::DW_EH_PE_sdata4;
LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
dwarf::DW_EH_PE_sdata4;
} else {
PersonalityEncoding = dwarf::DW_EH_PE_absptr;
LSDAEncoding = dwarf::DW_EH_PE_absptr;
TTypeEncoding = dwarf::DW_EH_PE_absptr;
}
break;
default:
break;
}
unsigned EHSectionType = T.getArch() == Triple::x86_64
? ELF::SHT_X86_64_UNWIND
: ELF::SHT_PROGBITS;
// Solaris requires different flags for .eh_frame to seemingly every other
// platform.
unsigned EHSectionFlags = ELF::SHF_ALLOC;
if (T.isOSSolaris() && T.getArch() != Triple::x86_64)
EHSectionFlags |= ELF::SHF_WRITE;
// ELF
BSSSection = Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
ELF::SHF_WRITE | ELF::SHF_ALLOC);
TextSection = Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
ELF::SHF_EXECINSTR | ELF::SHF_ALLOC);
DataSection = Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
ELF::SHF_WRITE | ELF::SHF_ALLOC);
ReadOnlySection =
Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
TLSDataSection =
Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
TLSBSSSection = Ctx->getELFSection(
".tbss", ELF::SHT_NOBITS, ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
DataRelROSection = Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
ELF::SHF_ALLOC | ELF::SHF_WRITE);
MergeableConst4Section =
Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
ELF::SHF_ALLOC | ELF::SHF_MERGE, 4, "");
MergeableConst8Section =
Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
ELF::SHF_ALLOC | ELF::SHF_MERGE, 8, "");
MergeableConst16Section =
Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
ELF::SHF_ALLOC | ELF::SHF_MERGE, 16, "");
StaticCtorSection = Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS,
ELF::SHF_ALLOC | ELF::SHF_WRITE);
StaticDtorSection = Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS,
ELF::SHF_ALLOC | ELF::SHF_WRITE);
// Exception Handling Sections.
// FIXME: We're emitting LSDA info into a readonly section on ELF, even though
// it contains relocatable pointers. In PIC mode, this is probably a big
// runtime hit for C++ apps. Either the contents of the LSDA need to be
// adjusted or this should be a data section.
LSDASection = Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
ELF::SHF_ALLOC);
COFFDebugSymbolsSection = nullptr;
// Debug Info Sections.
DwarfAbbrevSection = Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0,
"section_abbrev");
DwarfInfoSection =
Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0, "section_info");
DwarfLineSection = Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0);
DwarfFrameSection = Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0);
DwarfPubNamesSection =
Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0);
DwarfPubTypesSection =
Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0);
DwarfGnuPubNamesSection =
Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0);
DwarfGnuPubTypesSection =
Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0);
DwarfStrSection =
Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
DwarfLocSection = Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0);
DwarfARangesSection =
Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0);
DwarfRangesSection =
Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0, "debug_range");
// DWARF5 Experimental Debug Info
// Accelerator Tables
DwarfAccelNamesSection =
Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0, "names_begin");
DwarfAccelObjCSection =
Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0, "objc_begin");
DwarfAccelNamespaceSection = Ctx->getELFSection(
".apple_namespaces", ELF::SHT_PROGBITS, 0, "namespac_begin");
DwarfAccelTypesSection =
Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0, "types_begin");
// Fission Sections
DwarfInfoDWOSection =
Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0);
DwarfTypesDWOSection =
Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS, 0);
DwarfAbbrevDWOSection =
Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0);
DwarfStrDWOSection =
Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
DwarfLineDWOSection =
Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0);
DwarfLocDWOSection =
Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0, "skel_loc");
DwarfStrOffDWOSection =
Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0);
DwarfAddrSection =
Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0, "addr_sec");
StackMapSection =
Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
FaultMapSection =
Ctx->getELFSection(".llvm_faultmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
EHFrameSection =
Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags);
}
void MCObjectFileInfo::initCOFFMCObjectFileInfo(Triple T) {
EHFrameSection = Ctx->getCOFFSection(
".eh_frame", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
SectionKind::getData());
bool IsWoA = T.getArch() == Triple::arm || T.getArch() == Triple::thumb;
CommDirectiveSupportsAlignment = true;
// COFF
BSSSection = Ctx->getCOFFSection(
".bss", COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
SectionKind::getBSS());
TextSection = Ctx->getCOFFSection(
".text",
(IsWoA ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0) |
COFF::IMAGE_SCN_CNT_CODE | COFF::IMAGE_SCN_MEM_EXECUTE |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getText());
DataSection = Ctx->getCOFFSection(
".data", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
COFF::IMAGE_SCN_MEM_WRITE,
SectionKind::getData());
ReadOnlySection = Ctx->getCOFFSection(
".rdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
SectionKind::getReadOnly());
if (T.isKnownWindowsMSVCEnvironment() || T.isWindowsItaniumEnvironment()) {
StaticCtorSection =
Ctx->getCOFFSection(".CRT$XCU", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getReadOnly());
StaticDtorSection =
Ctx->getCOFFSection(".CRT$XTX", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getReadOnly());
} else {
StaticCtorSection = Ctx->getCOFFSection(
".ctors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
SectionKind::getData());
StaticDtorSection = Ctx->getCOFFSection(
".dtors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
SectionKind::getData());
}
// FIXME: We're emitting LSDA info into a readonly section on COFF, even
// though it contains relocatable pointers. In PIC mode, this is probably a
// big runtime hit for C++ apps. Either the contents of the LSDA need to be
// adjusted or this should be a data section.
assert(T.isOSWindows() && "Windows is the only supported COFF target");
if (T.getArch() == Triple::x86_64) {
// On Windows 64 with SEH, the LSDA is emitted into the .xdata section
LSDASection = nullptr;
} else {
LSDASection = Ctx->getCOFFSection(".gcc_except_table",
COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getReadOnly());
}
// Debug info.
COFFDebugSymbolsSection =
Ctx->getCOFFSection(".debug$S", COFF::IMAGE_SCN_MEM_DISCARDABLE |
COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata());
DwarfAbbrevSection = Ctx->getCOFFSection(
".debug_abbrev",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata(), "section_abbrev");
DwarfInfoSection = Ctx->getCOFFSection(
".debug_info",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata(), "section_info");
DwarfLineSection = Ctx->getCOFFSection(
".debug_line",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata(), "section_line");
DwarfFrameSection = Ctx->getCOFFSection(
".debug_frame",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata());
DwarfPubNamesSection = Ctx->getCOFFSection(
".debug_pubnames",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata());
DwarfPubTypesSection = Ctx->getCOFFSection(
".debug_pubtypes",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata());
DwarfGnuPubNamesSection = Ctx->getCOFFSection(
".debug_gnu_pubnames",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata());
DwarfGnuPubTypesSection = Ctx->getCOFFSection(
".debug_gnu_pubtypes",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata());
DwarfStrSection = Ctx->getCOFFSection(
".debug_str",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata(), "info_string");
DwarfLocSection = Ctx->getCOFFSection(
".debug_loc",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata(), "section_debug_loc");
DwarfARangesSection = Ctx->getCOFFSection(
".debug_aranges",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata());
DwarfRangesSection = Ctx->getCOFFSection(
".debug_ranges",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata(), "debug_range");
DwarfInfoDWOSection = Ctx->getCOFFSection(
".debug_info.dwo",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata(), "section_info_dwo");
DwarfTypesDWOSection = Ctx->getCOFFSection(
".debug_types.dwo",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata(), "section_types_dwo");
DwarfAbbrevDWOSection = Ctx->getCOFFSection(
".debug_abbrev.dwo",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata(), "section_abbrev_dwo");
DwarfStrDWOSection = Ctx->getCOFFSection(
".debug_str.dwo",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata(), "skel_string");
DwarfLineDWOSection = Ctx->getCOFFSection(
".debug_line.dwo",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata());
DwarfLocDWOSection = Ctx->getCOFFSection(
".debug_loc.dwo",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata(), "skel_loc");
DwarfStrOffDWOSection = Ctx->getCOFFSection(
".debug_str_offsets.dwo",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata());
DwarfAddrSection = Ctx->getCOFFSection(
".debug_addr",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata(), "addr_sec");
DwarfAccelNamesSection = Ctx->getCOFFSection(
".apple_names",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata(), "names_begin");
DwarfAccelNamespaceSection = Ctx->getCOFFSection(
".apple_namespaces",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata(), "namespac_begin");
DwarfAccelTypesSection = Ctx->getCOFFSection(
".apple_types",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata(), "types_begin");
DwarfAccelObjCSection = Ctx->getCOFFSection(
".apple_objc",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata(), "objc_begin");
DrectveSection = Ctx->getCOFFSection(
".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE,
SectionKind::getMetadata());
PDataSection = Ctx->getCOFFSection(
".pdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
SectionKind::getData());
XDataSection = Ctx->getCOFFSection(
".xdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
SectionKind::getData());
SXDataSection = Ctx->getCOFFSection(".sxdata", COFF::IMAGE_SCN_LNK_INFO,
SectionKind::getMetadata());
TLSDataSection = Ctx->getCOFFSection(
".tls$", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
COFF::IMAGE_SCN_MEM_WRITE,
SectionKind::getData());
StackMapSection = Ctx->getCOFFSection(".llvm_stackmaps",
COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getReadOnly());
}
void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple,
Reloc::Model relocm,
CodeModel::Model cm,
MCContext &ctx) {
RelocM = relocm;
CMModel = cm;
Ctx = &ctx;
// Common.
CommDirectiveSupportsAlignment = true;
SupportsWeakOmittedEHFrame = true;
SupportsCompactUnwindWithoutEHFrame = false;
OmitDwarfIfHaveCompactUnwind = false;
PersonalityEncoding = LSDAEncoding = FDECFIEncoding = TTypeEncoding =
dwarf::DW_EH_PE_absptr;
CompactUnwindDwarfEHFrameOnly = 0;
EHFrameSection = nullptr; // Created on demand.
CompactUnwindSection = nullptr; // Used only by selected targets.
DwarfAccelNamesSection = nullptr; // Used only by selected targets.
DwarfAccelObjCSection = nullptr; // Used only by selected targets.
DwarfAccelNamespaceSection = nullptr; // Used only by selected targets.
DwarfAccelTypesSection = nullptr; // Used only by selected targets.
TT = TheTriple;
Triple::ArchType Arch = TT.getArch();
// FIXME: Checking for Arch here to filter out bogus triples such as
// cellspu-apple-darwin. Perhaps we should fix in Triple?
if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
Arch == Triple::arm || Arch == Triple::thumb ||
Arch == Triple::aarch64 ||
Arch == Triple::ppc || Arch == Triple::ppc64 ||
Arch == Triple::UnknownArch) &&
TT.isOSBinFormatMachO()) {
Env = IsMachO;
initMachOMCObjectFileInfo(TT);
} else if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
Arch == Triple::arm || Arch == Triple::thumb) &&
(TT.isOSWindows() && TT.getObjectFormat() == Triple::COFF)) {
Env = IsCOFF;
initCOFFMCObjectFileInfo(TT);
} else {
Env = IsELF;
initELFMCObjectFileInfo(TT);
}
}
void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model RM,
CodeModel::Model CM,
MCContext &ctx) {
InitMCObjectFileInfo(Triple(TT), RM, CM, ctx);
}
MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP,
0, utostr(Hash));
}