static unsigned
getCOFFSectionFlags(SectionKind K) {
unsigned Flags = 0;
if (K.isMetadata())
Flags |=
COFF::IMAGE_SCN_MEM_DISCARDABLE;
else if (K.isText())
Flags |=
COFF::IMAGE_SCN_MEM_EXECUTE |
COFF::IMAGE_SCN_MEM_READ |
COFF::IMAGE_SCN_CNT_CODE;
else if (K.isBSS ())
Flags |=
COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ |
COFF::IMAGE_SCN_MEM_WRITE;
else if (K.isReadOnly())
Flags |=
COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ;
else if (K.isWriteable())
Flags |=
COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ |
COFF::IMAGE_SCN_MEM_WRITE;
return Flags;
}
/// IsGlobalInSmallSection - Return true if this global address should be
/// placed into small data/bss section.
bool MipsTargetObjectFile::
IsGlobalInSmallSection(const GlobalValue *GV, const TargetMachine &TM,
SectionKind Kind) const {
// Only use small section for non linux targets.
const MipsSubtarget &Subtarget = TM.getSubtarget<MipsSubtarget>();
if (Subtarget.isLinux())
return false;
// Only global variables, not functions.
const GlobalVariable *GVA = dyn_cast<GlobalVariable>(GV);
if (!GVA)
return false;
// We can only do this for datarel or BSS objects for now.
if (!Kind.isBSS() && !Kind.isDataRel())
return false;
// If this is a internal constant string, there is a special
// section for it, but not in small data/bss.
if (Kind.isMergeable1ByteCString())
return false;
const Type *Ty = GV->getType()->getElementType();
return IsInSmallSection(TM.getTargetData()->getTypeAllocSize(Ty));
}
// .section name [, "flags"] [, identifier [ identifier ], identifier]
//
// Supported flags:
// a: Ignored.
// b: BSS section (uninitialized data)
// d: data section (initialized data)
// n: Discardable section
// r: Readable section
// s: Shared section
// w: Writable section
// x: Executable section
// y: Not-readable section (clears 'r')
//
// Subsections are not supported.
bool COFFAsmParser::ParseDirectiveSection(StringRef, SMLoc) {
StringRef SectionName;
if (ParseSectionName(SectionName))
return TokError("expected identifier in directive");
unsigned Flags = COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ |
COFF::IMAGE_SCN_MEM_WRITE;
if (getLexer().is(AsmToken::Comma)) {
Lex();
if (getLexer().isNot(AsmToken::String))
return TokError("expected string in directive");
StringRef FlagsStr = getTok().getStringContents();
Lex();
if (ParseSectionFlags(FlagsStr, &Flags))
return true;
}
COFF::COMDATType Type = (COFF::COMDATType)0;
StringRef COMDATSymName;
if (getLexer().is(AsmToken::Comma)) {
Type = COFF::IMAGE_COMDAT_SELECT_ANY;
Lex();
Flags |= COFF::IMAGE_SCN_LNK_COMDAT;
if (!getLexer().is(AsmToken::Identifier))
return TokError("expected comdat type such as 'discard' or 'largest' "
"after protection bits");
if (parseCOMDATType(Type))
return true;
if (getLexer().isNot(AsmToken::Comma))
return TokError("expected comma in directive");
Lex();
if (getParser().parseIdentifier(COMDATSymName))
return TokError("expected identifier in directive");
}
if (getLexer().isNot(AsmToken::EndOfStatement))
return TokError("unexpected token in directive");
SectionKind Kind = computeSectionKind(Flags);
if (Kind.isText()) {
const Triple &T = getContext().getObjectFileInfo()->getTargetTriple();
if (T.getArch() == Triple::arm || T.getArch() == Triple::thumb)
Flags |= COFF::IMAGE_SCN_MEM_16BIT;
}
ParseSectionSwitch(SectionName, Flags, Kind, COMDATSymName, Type);
return false;
}
static unsigned
getELFSectionFlags(SectionKind K) {
unsigned Flags = 0;
if (!K.isMetadata())
Flags |= ELF::SHF_ALLOC;
if (K.isText())
Flags |= ELF::SHF_EXECINSTR;
if (K.isWriteable())
Flags |= ELF::SHF_WRITE;
if (K.isThreadLocal())
Flags |= ELF::SHF_TLS;
// K.isMergeableConst() is left out to honour PR4650
if (K.isMergeableCString() || K.isMergeableConst4() ||
K.isMergeableConst8() || K.isMergeableConst16())
Flags |= ELF::SHF_MERGE;
if (K.isMergeableCString())
Flags |= ELF::SHF_STRINGS;
return Flags;
}
static unsigned getELFSectionFlags(SectionKind K) {
unsigned Flags = 0;
if (!K.isMetadata())
Flags |= ELF::SHF_ALLOC;
if (K.isText())
Flags |= ELF::SHF_EXECINSTR;
if (K.isExecuteOnly())
Flags |= ELF::SHF_ARM_PURECODE;
if (K.isWriteable())
Flags |= ELF::SHF_WRITE;
if (K.isThreadLocal())
Flags |= ELF::SHF_TLS;
if (K.isMergeableCString() || K.isMergeableConst())
Flags |= ELF::SHF_MERGE;
if (K.isMergeableCString())
Flags |= ELF::SHF_STRINGS;
return Flags;
}
static unsigned getXCoreSectionFlags(SectionKind K, bool IsCPRel) {
unsigned Flags = 0;
if (!K.isMetadata())
Flags |= ELF::SHF_ALLOC;
if (K.isText())
Flags |= ELF::SHF_EXECINSTR;
else if (IsCPRel)
Flags |= ELF::XCORE_SHF_CP_SECTION;
else
Flags |= ELF::XCORE_SHF_DP_SECTION;
if (K.isWriteable())
Flags |= ELF::SHF_WRITE;
if (K.isMergeableCString() || K.isMergeableConst4() ||
K.isMergeableConst8() || K.isMergeableConst16())
Flags |= ELF::SHF_MERGE;
if (K.isMergeableCString())
Flags |= ELF::SHF_STRINGS;
return Flags;
}
/// IsGlobalInSmallSection - Return true if this global value should be
/// placed into small data/bss section.
bool HexagonTargetObjectFile::
IsGlobalInSmallSection(const GlobalValue *GV, const TargetMachine &TM,
SectionKind Kind) const {
// Only global variables, not functions.
const GlobalVariable *GVA = dyn_cast<GlobalVariable>(GV);
if (!GVA)
return false;
if (Kind.isBSS() || Kind.isDataNoRel() || Kind.isCommon()) {
Type *Ty = GV->getType()->getElementType();
return IsInSmallSection(TM.getDataLayout()->getTypeAllocSize(Ty));
}
return false;
}
static unsigned getELFSectionType(StringRef Name, SectionKind K) {
if (Name == ".init_array")
return ELF::SHT_INIT_ARRAY;
if (Name == ".fini_array")
return ELF::SHT_FINI_ARRAY;
if (Name == ".preinit_array")
return ELF::SHT_PREINIT_ARRAY;
if (K.isBSS() || K.isThreadBSS())
return ELF::SHT_NOBITS;
return ELF::SHT_PROGBITS;
}
static bool isExecuteOnlyFunction(const GlobalObject *GO, SectionKind SK,
const TargetMachine &TM) {
if (const Function *F = dyn_cast<Function>(GO))
if (TM.getSubtarget<ARMSubtarget>(*F).genExecuteOnly() && SK.isText())
return true;
return false;
}
/// getSectionPrefixForGlobal - Return the section prefix name used by options
/// FunctionsSections and DataSections.
static StringRef getSectionPrefixForGlobal(SectionKind Kind) {
if (Kind.isText()) return ".text.";
if (Kind.isReadOnly()) return ".rodata.";
if (Kind.isBSS()) return ".bss.";
if (Kind.isThreadData()) return ".tdata.";
if (Kind.isThreadBSS()) return ".tbss.";
if (Kind.isDataNoRel()) return ".data.";
if (Kind.isDataRelLocal()) return ".data.rel.local.";
if (Kind.isDataRel()) return ".data.rel.";
if (Kind.isReadOnlyWithRelLocal()) return ".data.rel.ro.local.";
assert(Kind.isReadOnlyWithRel() && "Unknown section kind");
return ".data.rel.ro.";
}
static unsigned
getELFSectionFlags(SectionKind K, bool InCOMDAT) {
unsigned Flags = 0;
if (!K.isMetadata())
Flags |= ELF::SHF_ALLOC;
if (K.isText())
Flags |= ELF::SHF_EXECINSTR;
if (K.isWriteable())
Flags |= ELF::SHF_WRITE;
if (K.isThreadLocal())
Flags |= ELF::SHF_TLS;
// FIXME: There is nothing in ELF preventing an SHF_MERGE from being
// in a comdat. We just avoid it for now because we don't print
// those .sections correctly.
if (!InCOMDAT && (K.isMergeableCString() || K.isMergeableConst()))
Flags |= ELF::SHF_MERGE;
if (K.isMergeableCString())
Flags |= ELF::SHF_STRINGS;
return Flags;
}
static SectionKind getWasmKindForNamedSection(StringRef Name, SectionKind K) {
// If we're told we have function data, then use that.
if (K.isText())
return SectionKind::getText();
// Otherwise, ignore whatever section type the generic impl detected and use
// a plain data section.
return SectionKind::getData();
}
static unsigned getELFSectionType(StringRef Name, SectionKind K) {
// Use SHT_NOTE for section whose name starts with ".note" to allow
// emitting ELF notes from C variable declaration.
// See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77609
if (Name.startswith(".note"))
return ELF::SHT_NOTE;
if (Name == ".init_array")
return ELF::SHT_INIT_ARRAY;
if (Name == ".fini_array")
return ELF::SHT_FINI_ARRAY;
if (Name == ".preinit_array")
return ELF::SHT_PREINIT_ARRAY;
if (K.isBSS() || K.isThreadBSS())
return ELF::SHT_NOBITS;
return ELF::SHT_PROGBITS;
}
SVMProgramSection SVMMemoryLayout::getSectionKind(const MCSectionData *SD) const
{
/*
* Categorize a MCSection as one of the several predefined
* SVMProgramSection types. This determines which program section
* we'll lump it in with, or whether it'll be included as debug-only.
*
* This value can be specifically overridden with setSectionKind().
* If we have no override, we calculate the proper section kind
* using the section's name, size, type, and other data.
*/
SectionKindOverrides_t::const_iterator it = SectionKindOverrides.find(SD);
if (it != SectionKindOverrides.end())
return it->second;
const MCSection *S = &SD->getSection();
SectionKind k = S->getKind();
const MCSectionELF *SE = dyn_cast<MCSectionELF>(S);
assert(SE);
StringRef Name = SE->getSectionName();
if (Name == ".metadata")
return SPS_META;
if (Name.startswith(".debug_"))
return SPS_DEBUG;
if (k.isBSS())
return SPS_BSS;
if (SE->getType() == ELF::SHT_PROGBITS) {
if (k.isReadOnly() || k.isText())
return SPS_RO;
if (k.isGlobalWriteableData())
return SPS_RW_PLAIN;
}
return SPS_DEBUG;
}
unsigned MCSectionELF::DetermineEntrySize(SectionKind Kind) {
if (Kind.isMergeable1ByteCString()) return 1;
if (Kind.isMergeable2ByteCString()) return 2;
if (Kind.isMergeable4ByteCString()) return 4;
if (Kind.isMergeableConst4()) return 4;
if (Kind.isMergeableConst8()) return 8;
if (Kind.isMergeableConst16()) return 16;
return 0;
}
static unsigned
getCOFFSectionFlags(SectionKind K, const TargetMachine &TM) {
unsigned Flags = 0;
bool isThumb = TM.getTargetTriple().getArch() == Triple::thumb;
if (K.isMetadata())
Flags |=
COFF::IMAGE_SCN_MEM_DISCARDABLE;
else if (K.isText())
Flags |=
COFF::IMAGE_SCN_MEM_EXECUTE |
COFF::IMAGE_SCN_MEM_READ |
COFF::IMAGE_SCN_CNT_CODE |
(isThumb ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0);
else if (K.isBSS())
Flags |=
COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ |
COFF::IMAGE_SCN_MEM_WRITE;
else if (K.isThreadLocal())
Flags |=
COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ |
COFF::IMAGE_SCN_MEM_WRITE;
else if (K.isReadOnly() || K.isReadOnlyWithRel())
Flags |=
COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ;
else if (K.isWriteable())
Flags |=
COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ |
COFF::IMAGE_SCN_MEM_WRITE;
return Flags;
}
// EmitGlobal - Choose the right section for global and emit it
void ELFWriter::EmitGlobal(const GlobalValue *GV) {
// Check if the referenced symbol is already emitted
if (GblSymLookup.find(GV) != GblSymLookup.end())
return;
// Handle ELF Bind, Visibility and Type for the current symbol
unsigned SymBind = getGlobalELFBinding(GV);
unsigned SymType = getGlobalELFType(GV);
bool IsUndefSym = IsELFUndefSym(GV);
ELFSym *GblSym = IsUndefSym ? ELFSym::getUndefGV(GV, SymBind)
: ELFSym::getGV(GV, SymBind, SymType, getGlobalELFVisibility(GV));
if (!IsUndefSym) {
assert(isa<GlobalVariable>(GV) && "GV not a global variable!");
const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV);
// Handle special llvm globals
if (EmitSpecialLLVMGlobal(GVar))
return;
// Get the ELF section where this global belongs from TLOF
const MCSectionELF *S =
(const MCSectionELF *)TLOF.SectionForGlobal(GV, Mang, TM);
ELFSection &ES =
getSection(S->getSectionName(), S->getType(), S->getFlags());
SectionKind Kind = S->getKind();
// The symbol align should update the section alignment if needed
const TargetData *TD = TM.getTargetData();
unsigned Align = TD->getPreferredAlignment(GVar);
unsigned Size = TD->getTypeAllocSize(GVar->getInitializer()->getType());
GblSym->Size = Size;
if (HasCommonSymbols(*S)) { // Symbol must go to a common section
GblSym->SectionIdx = ELF::SHN_COMMON;
// A new linkonce section is created for each global in the
// common section, the default alignment is 1 and the symbol
// value contains its alignment.
ES.Align = 1;
GblSym->Value = Align;
} else if (Kind.isBSS() || Kind.isThreadBSS()) { // Symbol goes to BSS.
GblSym->SectionIdx = ES.SectionIdx;
// Update the size with alignment and the next object can
// start in the right offset in the section
if (Align) ES.Size = (ES.Size + Align-1) & ~(Align-1);
ES.Align = std::max(ES.Align, Align);
// GblSym->Value should contain the virtual offset inside the section.
// Virtual because the BSS space is not allocated on ELF objects
GblSym->Value = ES.Size;
ES.Size += Size;
} else { // The symbol must go to some kind of data section
GblSym->SectionIdx = ES.SectionIdx;
// GblSym->Value should contain the symbol offset inside the section,
// and all symbols should start on their required alignment boundary
ES.Align = std::max(ES.Align, Align);
ES.emitAlignment(Align);
GblSym->Value = ES.size();
// Emit the global to the data section 'ES'
EmitGlobalConstant(GVar->getInitializer(), ES);
}
}
AddToSymbolList(GblSym);
}
static unsigned getXCoreSectionType(SectionKind K) {
if (K.isBSS())
return ELF::SHT_NOBITS;
return ELF::SHT_PROGBITS;
}
// Return true if this global address should be placed into small data/bss
// section.
bool LanaiTargetObjectFile::isGlobalInSmallSection(const GlobalValue *GV,
const TargetMachine &TM,
SectionKind Kind) const {
return (isGlobalInSmallSectionImpl(GV, TM) &&
(Kind.isData() || Kind.isBSS() || Kind.isCommon()));
}
/// Return the section prefix name used by options FunctionsSections and
/// DataSections.
static StringRef getSectionPrefixForGlobal(SectionKind Kind) {
if (Kind.isTexTramp())
return ".tramp.";
if (Kind.isText())
return ".text";
if (Kind.isReadOnly())
return ".rodata";
if (Kind.isBSS())
return ".bss";
if (Kind.isThreadData())
return ".tdata";
if (Kind.isThreadBSS())
return ".tbss";
if (Kind.isData())
return ".data";
if (Kind.isTexTrap())
return ".textrap.";
if (Kind.isTexTrapText())
return ".textrap.";
if (Kind.isTexTramp())
return ".text.xvtable.";
assert(Kind.isReadOnlyWithRel() && "Unknown section kind");
return ".data.rel.ro";
}
/// IsGlobalInSmallSection - Return true if this global address should be
/// placed into small data/bss section.
bool TriCoreTargetObjectFile::
IsGlobalInSmallSection(const GlobalValue *GV, const TargetMachine &TM,
SectionKind Kind) const {
return (IsGlobalInSmallSectionImpl(GV, TM) &&
(Kind.isDataRel() || Kind.isBSS() || Kind.isCommon()));
}
