llvm/lib/MC/MCObjectFileInfo.cpp
Zachary Turner 19ca2b0f9d Move Object format code to lib/BinaryFormat.
This creates a new library called BinaryFormat that has all of
the headers from llvm/Support containing structure and layout
definitions for various types of binary formats like dwarf, coff,
elf, etc as well as the code for identifying a file from its
magic.

Differential Revision: https://reviews.llvm.org/D33843

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304864 91177308-0d34-0410-b5e6-96231b3b80d8
2017-06-07 03:48:56 +00:00

909 lines
37 KiB
C++

//===-- MCObjectFileInfo.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/BinaryFormat/COFF.h"
#include "llvm/BinaryFormat/ELF.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/MC/MCSectionWasm.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.isWatchABI())
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(const 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.isWatchABI())
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());
ThreadLocalPointerSection
= Ctx->getMachOSection("__DATA", "__thread_ptr",
MachO::S_THREAD_LOCAL_VARIABLE_POINTERS,
SectionKind::getMetadata());
// Exception Handling.
LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0,
SectionKind::getReadOnlyWithRel());
COFFDebugSymbolsSection = nullptr;
COFFDebugTypesSection = 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");
DwarfStrOffSection =
Ctx->getMachOSection("__DWARF", "__debug_str_offs", MachO::S_ATTR_DEBUG,
SectionKind::getMetadata(), "section_str_off");
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");
DwarfMacinfoSection =
Ctx->getMachOSection("__DWARF", "__debug_macinfo", MachO::S_ATTR_DEBUG,
SectionKind::getMetadata(), "debug_macinfo");
DwarfDebugInlineSection =
Ctx->getMachOSection("__DWARF", "__debug_inlined", MachO::S_ATTR_DEBUG,
SectionKind::getMetadata());
DwarfCUIndexSection =
Ctx->getMachOSection("__DWARF", "__debug_cu_index", MachO::S_ATTR_DEBUG,
SectionKind::getMetadata());
DwarfTUIndexSection =
Ctx->getMachOSection("__DWARF", "__debug_tu_index", 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(const 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;
case Triple::bpfel:
case Triple::bpfeb:
FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
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
LLVM_FALLTHROUGH;
case Triple::ppc:
case Triple::x86:
PersonalityEncoding = PositionIndependent
? dwarf::DW_EH_PE_indirect |
dwarf::DW_EH_PE_pcrel |
dwarf::DW_EH_PE_sdata4
: dwarf::DW_EH_PE_absptr;
LSDAEncoding = PositionIndependent
? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
: dwarf::DW_EH_PE_absptr;
TTypeEncoding = PositionIndependent
? 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 (PositionIndependent) {
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::hexagon:
PersonalityEncoding = dwarf::DW_EH_PE_absptr;
LSDAEncoding = dwarf::DW_EH_PE_absptr;
FDECFIEncoding = dwarf::DW_EH_PE_absptr;
TTypeEncoding = dwarf::DW_EH_PE_absptr;
if (PositionIndependent) {
PersonalityEncoding |= dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel;
LSDAEncoding |= dwarf::DW_EH_PE_pcrel;
FDECFIEncoding |= dwarf::DW_EH_PE_pcrel;
TTypeEncoding |= dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel;
}
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 (PositionIndependent) {
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::lanai:
LSDAEncoding = dwarf::DW_EH_PE_absptr;
PersonalityEncoding = 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.
// FreeBSD must be explicit about the data size and using pcrel since it's
// assembler/linker won't do the automatic conversion that the Linux tools
// do.
if (T.isOSFreeBSD()) {
PersonalityEncoding |= dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
}
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 (PositionIndependent) {
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 (PositionIndependent) {
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 (PositionIndependent) {
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, "");
MergeableConst32Section =
Ctx->getELFSection(".rodata.cst32", ELF::SHT_PROGBITS,
ELF::SHF_ALLOC | ELF::SHF_MERGE, 32, "");
// 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;
COFFDebugTypesSection = nullptr;
unsigned DebugSecType = ELF::SHT_PROGBITS;
// MIPS .debug_* sections should have SHT_MIPS_DWARF section type
// to distinguish among sections contain DWARF and ECOFF debug formats.
// Sections with ECOFF debug format are obsoleted and marked by SHT_PROGBITS.
if (T.getArch() == Triple::mips || T.getArch() == Triple::mipsel ||
T.getArch() == Triple::mips64 || T.getArch() == Triple::mips64el)
DebugSecType = ELF::SHT_MIPS_DWARF;
// Debug Info Sections.
DwarfAbbrevSection =
Ctx->getELFSection(".debug_abbrev", DebugSecType, 0);
DwarfInfoSection = Ctx->getELFSection(".debug_info", DebugSecType, 0);
DwarfLineSection = Ctx->getELFSection(".debug_line", DebugSecType, 0);
DwarfFrameSection = Ctx->getELFSection(".debug_frame", DebugSecType, 0);
DwarfPubNamesSection =
Ctx->getELFSection(".debug_pubnames", DebugSecType, 0);
DwarfPubTypesSection =
Ctx->getELFSection(".debug_pubtypes", DebugSecType, 0);
DwarfGnuPubNamesSection =
Ctx->getELFSection(".debug_gnu_pubnames", DebugSecType, 0);
DwarfGnuPubTypesSection =
Ctx->getELFSection(".debug_gnu_pubtypes", DebugSecType, 0);
DwarfStrSection =
Ctx->getELFSection(".debug_str", DebugSecType,
ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
DwarfLocSection = Ctx->getELFSection(".debug_loc", DebugSecType, 0);
DwarfARangesSection =
Ctx->getELFSection(".debug_aranges", DebugSecType, 0);
DwarfRangesSection =
Ctx->getELFSection(".debug_ranges", DebugSecType, 0);
DwarfMacinfoSection =
Ctx->getELFSection(".debug_macinfo", DebugSecType, 0);
// DWARF5 Experimental Debug Info
// Accelerator Tables
DwarfAccelNamesSection =
Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0);
DwarfAccelObjCSection =
Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0);
DwarfAccelNamespaceSection =
Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0);
DwarfAccelTypesSection =
Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0);
// String Offset and Address Sections
DwarfStrOffSection =
Ctx->getELFSection(".debug_str_offsets", DebugSecType, 0);
DwarfAddrSection = Ctx->getELFSection(".debug_addr", DebugSecType, 0);
// Fission Sections
DwarfInfoDWOSection =
Ctx->getELFSection(".debug_info.dwo", DebugSecType, 0);
DwarfTypesDWOSection =
Ctx->getELFSection(".debug_types.dwo", DebugSecType, 0);
DwarfAbbrevDWOSection =
Ctx->getELFSection(".debug_abbrev.dwo", DebugSecType, 0);
DwarfStrDWOSection =
Ctx->getELFSection(".debug_str.dwo", DebugSecType,
ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
DwarfLineDWOSection =
Ctx->getELFSection(".debug_line.dwo", DebugSecType, 0);
DwarfLocDWOSection =
Ctx->getELFSection(".debug_loc.dwo", DebugSecType, 0);
DwarfStrOffDWOSection =
Ctx->getELFSection(".debug_str_offsets.dwo", DebugSecType, 0);
// DWP Sections
DwarfCUIndexSection =
Ctx->getELFSection(".debug_cu_index", DebugSecType, 0);
DwarfTUIndexSection =
Ctx->getELFSection(".debug_tu_index", DebugSecType, 0);
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(const 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());
// Set the `IMAGE_SCN_MEM_16BIT` flag when compiling for thumb mode. This is
// used to indicate to the linker that the text segment contains thumb instructions
// and to set the ISA selection bit for calls accordingly.
const bool IsThumb = 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",
(IsThumb ? 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());
// 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.
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$S", (COFF::IMAGE_SCN_MEM_DISCARDABLE |
COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ),
SectionKind::getMetadata());
COFFDebugTypesSection =
Ctx->getCOFFSection(".debug$T", (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");
DwarfStrOffSection = Ctx->getCOFFSection(
".debug_str_offsets",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata(), "section_str_off");
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");
DwarfMacinfoSection = Ctx->getCOFFSection(
".debug_macinfo",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata(), "debug_macinfo");
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(), "section_str_off_dwo");
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");
DwarfCUIndexSection = Ctx->getCOFFSection(
".debug_cu_index",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata());
DwarfTUIndexSection = Ctx->getCOFFSection(
".debug_tu_index",
COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ,
SectionKind::getMetadata());
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::initWasmMCObjectFileInfo(const Triple &T) {
// TODO: Set the section types and flags.
TextSection = Ctx->getWasmSection(".text", 0, 0);
DataSection = Ctx->getWasmSection(".data", 0, 0);
// TODO: Set the section types and flags.
DwarfLineSection = Ctx->getWasmSection(".debug_line", 0, 0);
DwarfStrSection = Ctx->getWasmSection(".debug_str", 0, 0);
DwarfLocSection = Ctx->getWasmSection(".debug_loc", 0, 0);
DwarfAbbrevSection = Ctx->getWasmSection(".debug_abbrev", 0, 0, "section_abbrev");
DwarfARangesSection = Ctx->getWasmSection(".debug_aranges", 0, 0);
DwarfRangesSection = Ctx->getWasmSection(".debug_ranges", 0, 0, "debug_range");
DwarfMacinfoSection = Ctx->getWasmSection(".debug_macinfo", 0, 0, "debug_macinfo");
DwarfAddrSection = Ctx->getWasmSection(".debug_addr", 0, 0);
DwarfCUIndexSection = Ctx->getWasmSection(".debug_cu_index", 0, 0);
DwarfTUIndexSection = Ctx->getWasmSection(".debug_tu_index", 0, 0);
DwarfInfoSection = Ctx->getWasmSection(".debug_info", 0, 0, "section_info");
DwarfFrameSection = Ctx->getWasmSection(".debug_frame", 0, 0);
DwarfPubNamesSection = Ctx->getWasmSection(".debug_pubnames", 0, 0);
DwarfPubTypesSection = Ctx->getWasmSection(".debug_pubtypes", 0, 0);
// TODO: Define more sections.
}
void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple, bool PIC,
CodeModel::Model cm,
MCContext &ctx) {
PositionIndependent = PIC;
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;
switch (TT.getObjectFormat()) {
case Triple::MachO:
Env = IsMachO;
initMachOMCObjectFileInfo(TT);
break;
case Triple::COFF:
if (!TT.isOSWindows())
report_fatal_error(
"Cannot initialize MC for non-Windows COFF object files.");
Env = IsCOFF;
initCOFFMCObjectFileInfo(TT);
break;
case Triple::ELF:
Env = IsELF;
initELFMCObjectFileInfo(TT);
break;
case Triple::Wasm:
Env = IsWasm;
initWasmMCObjectFileInfo(TT);
break;
case Triple::UnknownObjectFormat:
report_fatal_error("Cannot initialize MC for unknown object file format.");
break;
}
}
MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP,
0, utostr(Hash));
}