+static bool isSuitableForBSS(const GlobalVariable *GV) {
+ // Leave constant zeros in readonly constant sections, so they can be shared
+ Constant *C = GV->getInitializer();
+ return (C->isNullValue() && !GV->isConstant() && !NoZerosInBSS);
+}
+
+static bool isConstantString(const Constant *C) {
+ // First check: is we have constant array of i8 terminated with zero
+ const ConstantArray *CVA = dyn_cast<ConstantArray>(C);
+ // Check, if initializer is a null-terminated string
+ if (CVA && CVA->isCString())
+ return true;
+
+ // Another possibility: [1 x i8] zeroinitializer
+ if (isa<ConstantAggregateZero>(C))
+ if (const ArrayType *Ty = dyn_cast<ArrayType>(C->getType()))
+ return (Ty->getElementType() == Type::Int8Ty &&
+ Ty->getNumElements() == 1);
+
+ return false;
+}
+
+static unsigned SectionFlagsForGlobal(const GlobalValue *GV,
+ SectionKind::Kind Kind) {
+ unsigned Flags = SectionFlags::None;
+
+ // Decode flags from global itself.
+ switch (Kind) {
+ case SectionKind::Text:
+ Flags |= SectionFlags::Code;
+ break;
+ case SectionKind::ThreadData:
+ case SectionKind::ThreadBSS:
+ Flags |= SectionFlags::TLS;
+ // FALLS THROUGH
+ case SectionKind::Data:
+ case SectionKind::DataRel:
+ case SectionKind::DataRelLocal:
+ case SectionKind::DataRelRO:
+ case SectionKind::DataRelROLocal:
+ case SectionKind::BSS:
+ Flags |= SectionFlags::Writeable;
+ break;
+ case SectionKind::ROData:
+ case SectionKind::RODataMergeStr:
+ case SectionKind::RODataMergeConst:
+ // No additional flags here
+ break;
+ default:
+ llvm_unreachable("Unexpected section kind!");
+ }
+
+ if (GV->isWeakForLinker())
+ Flags |= SectionFlags::Linkonce;
+
+ return Flags;
+}
+
+static SectionKind::Kind SectionKindForGlobal(const GlobalValue *GV,
+ Reloc::Model ReloModel) {
+ // Early exit - functions should be always in text sections.
+ const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV);
+ if (GVar == 0)
+ return SectionKind::Text;
+
+ bool isThreadLocal = GVar->isThreadLocal();
+
+ // Variable can be easily put to BSS section.
+ if (isSuitableForBSS(GVar))
+ return isThreadLocal ? SectionKind::ThreadBSS : SectionKind::BSS;
+
+ // If this is thread-local, put it in the general "thread_data" section.
+ if (isThreadLocal)
+ return SectionKind::ThreadData;
+
+ Constant *C = GVar->getInitializer();
+
+ // If the global is marked constant, we can put it into a mergable section,
+ // a mergable string section, or general .data if it contains relocations.
+ if (GVar->isConstant()) {
+ // If the initializer for the global contains something that requires a
+ // relocation, then we may have to drop this into a wriable data section
+ // even though it is marked const.
+ switch (C->getRelocationInfo()) {
+ default: llvm_unreachable("unknown relocation info kind");
+ case Constant::NoRelocation:
+ // If initializer is a null-terminated string, put it in a "cstring"
+ // section if the target has it.
+ if (isConstantString(C))
+ return SectionKind::RODataMergeStr;
+
+ // Otherwise, just drop it into a mergable constant section.
+ return SectionKind::RODataMergeConst;
+
+ case Constant::LocalRelocation:
+ // In static relocation model, the linker will resolve all addresses, so
+ // the relocation entries will actually be constants by the time the app
+ // starts up.
+ if (ReloModel == Reloc::Static)
+ return SectionKind::ROData;
+
+ // Otherwise, the dynamic linker needs to fix it up, put it in the
+ // writable data.rel.local section.
+ return SectionKind::DataRelROLocal;
+
+ case Constant::GlobalRelocations:
+ // In static relocation model, the linker will resolve all addresses, so
+ // the relocation entries will actually be constants by the time the app
+ // starts up.
+ if (ReloModel == Reloc::Static)
+ return SectionKind::ROData;
+
+ // Otherwise, the dynamic linker needs to fix it up, put it in the
+ // writable data.rel section.
+ return SectionKind::DataRelRO;
+ }
+ }
+
+ // Okay, this isn't a constant. If the initializer for the global is going
+ // to require a runtime relocation by the dynamic linker, put it into a more
+ // specific section to improve startup time of the app. This coalesces these
+ // globals together onto fewer pages, improving the locality of the dynamic
+ // linker.
+ if (ReloModel == Reloc::Static)
+ return SectionKind::Data;
+
+ switch (C->getRelocationInfo()) {
+ default: llvm_unreachable("unknown relocation info kind");
+ case Constant::NoRelocation: return SectionKind::Data;
+ case Constant::LocalRelocation: return SectionKind::DataRelLocal;
+ case Constant::GlobalRelocations: return SectionKind::DataRel;
+ }
+}
+
+
+const Section *TargetAsmInfo::SectionForGlobal(const GlobalValue *GV) const {
+ SectionKind::Kind Kind = SectionKindForGlobal(GV, TM.getRelocationModel());
+
+ // Select section name.
+ if (GV->hasSection()) {
+ // If the target has special section hacks for specifically named globals,
+ // return them now.
+ if (const Section *TS = getSpecialCasedSectionGlobals(GV, Kind))
+ return TS;
+
+ // Honour section already set, if any.
+ unsigned Flags = SectionFlagsForGlobal(GV, Kind);
+
+ // This is an explicitly named section.
+ Flags |= SectionFlags::Named;
+
+ // If the target has magic semantics for certain section names, make sure to
+ // pick up the flags. This allows the user to write things with attribute
+ // section and still get the appropriate section flags printed.
+ Flags |= getFlagsForNamedSection(GV->getSection().c_str());
+
+ return getNamedSection(GV->getSection().c_str(), Flags);
+ }
+
+ // 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 (GV->isWeakForLinker()) {
+ if (const char *Prefix = getSectionPrefixForUniqueGlobal(Kind)) {
+ unsigned Flags = SectionFlagsForGlobal(GV, Kind);
+
+ // FIXME: Use mangler interface (PR4584).
+ std::string Name = Prefix+GV->getNameStr();
+ return getNamedSection(Name.c_str(), Flags);
+ }
+ }
+
+ // Use default section depending on the 'type' of global
+ return SelectSectionForGlobal(GV, Kind);
+}
+
+// Lame default implementation. Calculate the section name for global.
+const Section*
+TargetAsmInfo::SelectSectionForGlobal(const GlobalValue *GV,
+ SectionKind::Kind Kind) const {
+ if (Kind == SectionKind::Text)
+ return getTextSection();
+
+ if (isBSS(Kind))
+ if (const Section *S = getBSSSection_())
+ return S;
+
+ if (SectionKind::isReadOnly(Kind))
+ if (const Section *S = getReadOnlySection())
+ return S;
+
+ return getDataSection();
+}
+
+/// getSectionForMergableConstant - Given a mergable constant with the
+/// specified size and relocation information, return a section that it
+/// should be placed in.
+const Section *
+TargetAsmInfo::getSectionForMergableConstant(uint64_t Size,
+ unsigned ReloInfo) const {
+ // FIXME: Support data.rel stuff someday
+ // Lame default implementation. Calculate the section name for machine const.
+ return getDataSection();
+}
+
+
+
+
+const char *
+TargetAsmInfo::getSectionPrefixForUniqueGlobal(SectionKind::Kind Kind) const {
+ switch (Kind) {
+ default: llvm_unreachable("Unknown section kind");
+ case SectionKind::Text: return ".gnu.linkonce.t.";
+ case SectionKind::Data: return ".gnu.linkonce.d.";
+ case SectionKind::DataRel: return ".gnu.linkonce.d.rel.";
+ case SectionKind::DataRelLocal: return ".gnu.linkonce.d.rel.local.";
+ case SectionKind::DataRelRO: return ".gnu.linkonce.d.rel.ro.";
+ case SectionKind::DataRelROLocal: return ".gnu.linkonce.d.rel.ro.local.";
+ case SectionKind::BSS: return ".gnu.linkonce.b.";
+ case SectionKind::ROData:
+ case SectionKind::RODataMergeConst:
+ case SectionKind::RODataMergeStr: return ".gnu.linkonce.r.";
+ case SectionKind::ThreadData: return ".gnu.linkonce.td.";
+ case SectionKind::ThreadBSS: return ".gnu.linkonce.tb.";
+ }
+}
+
+const Section *TargetAsmInfo::getNamedSection(const char *Name, unsigned Flags,
+ bool Override) const {
+ Section &S = Sections[Name];
+
+ // This is newly-created section, set it up properly.
+ if (S.Flags == SectionFlags::Invalid || Override) {
+ S.Flags = Flags | SectionFlags::Named;
+ S.Name = Name;
+ }
+
+ return &S;
+}
+
+const Section*
+TargetAsmInfo::getUnnamedSection(const char *Directive, unsigned Flags,
+ bool Override) const {
+ Section& S = Sections[Directive];
+
+ // This is newly-created section, set it up properly.
+ if (S.Flags == SectionFlags::Invalid || Override) {
+ S.Flags = Flags & ~SectionFlags::Named;
+ S.Name = Directive;
+ }
+
+ return &S;
+}
+
+const std::string&
+TargetAsmInfo::getSectionFlags(unsigned Flags) const {
+ SectionFlags::FlagsStringsMapType::iterator I = FlagsStrings.find(Flags);
+
+ // We didn't print these flags yet, print and save them to map. This reduces
+ // amount of heap trashing due to std::string construction / concatenation.
+ if (I == FlagsStrings.end())
+ I = FlagsStrings.insert(std::make_pair(Flags,
+ printSectionFlags(Flags))).first;
+
+ return I->second;
+}
+
+unsigned TargetAsmInfo::getULEB128Size(unsigned Value) {
+ unsigned Size = 0;
+ do {
+ Value >>= 7;
+ Size += sizeof(int8_t);
+ } while (Value);
+ return Size;
+}
+
+unsigned TargetAsmInfo::getSLEB128Size(int Value) {
+ unsigned Size = 0;
+ int Sign = Value >> (8 * sizeof(Value) - 1);
+ bool IsMore;
+
+ do {
+ unsigned Byte = Value & 0x7f;
+ Value >>= 7;
+ IsMore = Value != Sign || ((Byte ^ Sign) & 0x40) != 0;
+ Size += sizeof(int8_t);
+ } while (IsMore);
+ return Size;
+}