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-rw-r--r--lib/Target/TargetAsmInfo.cpp461
1 files changed, 461 insertions, 0 deletions
diff --git a/lib/Target/TargetAsmInfo.cpp b/lib/Target/TargetAsmInfo.cpp
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+//===-- TargetAsmInfo.cpp - Asm Info ---------------------------------------==//
+//
+// 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.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/GlobalVariable.h"
+#include "llvm/Function.h"
+#include "llvm/Module.h"
+#include "llvm/Type.h"
+#include "llvm/Target/TargetAsmInfo.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetOptions.h"
+#include "llvm/Support/Dwarf.h"
+#include <cctype>
+#include <cstring>
+
+using namespace llvm;
+
+void TargetAsmInfo::fillDefaultValues() {
+ BSSSection = "\t.bss";
+ BSSSection_ = 0;
+ ReadOnlySection = 0;
+ SmallDataSection = 0;
+ SmallBSSSection = 0;
+ SmallRODataSection = 0;
+ TLSDataSection = 0;
+ TLSBSSSection = 0;
+ ZeroFillDirective = 0;
+ NonexecutableStackDirective = 0;
+ NeedsSet = false;
+ MaxInstLength = 4;
+ PCSymbol = "$";
+ SeparatorChar = ';';
+ CommentString = "#";
+ GlobalPrefix = "";
+ PrivateGlobalPrefix = ".";
+ LessPrivateGlobalPrefix = "";
+ JumpTableSpecialLabelPrefix = 0;
+ GlobalVarAddrPrefix = "";
+ GlobalVarAddrSuffix = "";
+ FunctionAddrPrefix = "";
+ FunctionAddrSuffix = "";
+ PersonalityPrefix = "";
+ PersonalitySuffix = "";
+ NeedsIndirectEncoding = false;
+ InlineAsmStart = "#APP";
+ InlineAsmEnd = "#NO_APP";
+ AssemblerDialect = 0;
+ StringConstantPrefix = ".str";
+ ZeroDirective = "\t.zero\t";
+ ZeroDirectiveSuffix = 0;
+ AsciiDirective = "\t.ascii\t";
+ AscizDirective = "\t.asciz\t";
+ Data8bitsDirective = "\t.byte\t";
+ Data16bitsDirective = "\t.short\t";
+ Data32bitsDirective = "\t.long\t";
+ Data64bitsDirective = "\t.quad\t";
+ AlignDirective = "\t.align\t";
+ AlignmentIsInBytes = true;
+ TextAlignFillValue = 0;
+ SwitchToSectionDirective = "\t.section\t";
+ TextSectionStartSuffix = "";
+ DataSectionStartSuffix = "";
+ SectionEndDirectiveSuffix = 0;
+ ConstantPoolSection = "\t.section .rodata";
+ JumpTableDataSection = "\t.section .rodata";
+ JumpTableDirective = 0;
+ CStringSection = 0;
+ CStringSection_ = 0;
+ // FIXME: Flags are ELFish - replace with normal section stuff.
+ StaticCtorsSection = "\t.section .ctors,\"aw\",@progbits";
+ StaticDtorsSection = "\t.section .dtors,\"aw\",@progbits";
+ GlobalDirective = "\t.globl\t";
+ SetDirective = 0;
+ LCOMMDirective = 0;
+ COMMDirective = "\t.comm\t";
+ COMMDirectiveTakesAlignment = true;
+ HasDotTypeDotSizeDirective = true;
+ HasSingleParameterDotFile = true;
+ UsedDirective = 0;
+ WeakRefDirective = 0;
+ WeakDefDirective = 0;
+ // FIXME: These are ELFish - move to ELFTAI.
+ HiddenDirective = "\t.hidden\t";
+ ProtectedDirective = "\t.protected\t";
+ AbsoluteDebugSectionOffsets = false;
+ AbsoluteEHSectionOffsets = false;
+ HasLEB128 = false;
+ HasDotLocAndDotFile = false;
+ SupportsDebugInformation = false;
+ SupportsExceptionHandling = false;
+ DwarfRequiresFrameSection = true;
+ DwarfUsesInlineInfoSection = false;
+ SupportsMacInfoSection = true;
+ NonLocalEHFrameLabel = false;
+ GlobalEHDirective = 0;
+ SupportsWeakOmittedEHFrame = true;
+ DwarfSectionOffsetDirective = 0;
+ DwarfAbbrevSection = ".debug_abbrev";
+ DwarfInfoSection = ".debug_info";
+ DwarfLineSection = ".debug_line";
+ DwarfFrameSection = ".debug_frame";
+ DwarfPubNamesSection = ".debug_pubnames";
+ DwarfPubTypesSection = ".debug_pubtypes";
+ DwarfDebugInlineSection = ".debug_inlined";
+ DwarfStrSection = ".debug_str";
+ DwarfLocSection = ".debug_loc";
+ DwarfARangesSection = ".debug_aranges";
+ DwarfRangesSection = ".debug_ranges";
+ DwarfMacInfoSection = ".debug_macinfo";
+ DwarfEHFrameSection = ".eh_frame";
+ DwarfExceptionSection = ".gcc_except_table";
+ AsmTransCBE = 0;
+ TextSection = getUnnamedSection("\t.text", SectionFlags::Code);
+ DataSection = getUnnamedSection("\t.data", SectionFlags::Writeable);
+}
+
+TargetAsmInfo::TargetAsmInfo(const TargetMachine &tm)
+ : TM(tm) {
+ fillDefaultValues();
+}
+
+TargetAsmInfo::~TargetAsmInfo() {
+}
+
+/// Measure the specified inline asm to determine an approximation of its
+/// length.
+/// Comments (which run till the next SeparatorChar or newline) do not
+/// count as an instruction.
+/// Any other non-whitespace text is considered an instruction, with
+/// multiple instructions separated by SeparatorChar or newlines.
+/// Variable-length instructions are not handled here; this function
+/// may be overloaded in the target code to do that.
+unsigned TargetAsmInfo::getInlineAsmLength(const char *Str) const {
+ // Count the number of instructions in the asm.
+ bool atInsnStart = true;
+ unsigned Length = 0;
+ for (; *Str; ++Str) {
+ if (*Str == '\n' || *Str == SeparatorChar)
+ atInsnStart = true;
+ if (atInsnStart && !isspace(*Str)) {
+ Length += MaxInstLength;
+ atInsnStart = false;
+ }
+ if (atInsnStart && strncmp(Str, CommentString, strlen(CommentString))==0)
+ atInsnStart = false;
+ }
+
+ return Length;
+}
+
+unsigned TargetAsmInfo::PreferredEHDataFormat(DwarfEncoding::Target Reason,
+ bool Global) const {
+ return dwarf::DW_EH_PE_absptr;
+}
+
+static bool isSuitableForBSS(const GlobalVariable *GV) {
+ if (!GV->hasInitializer())
+ return true;
+
+ // 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;
+}
+
+unsigned TargetAsmInfo::RelocBehaviour() const {
+ // By default - all relocations in PIC mode would force symbol to be
+ // placed in r/w section.
+ return (TM.getRelocationModel() != Reloc::Static ?
+ Reloc::LocalOrGlobal : Reloc::None);
+}
+
+SectionKind::Kind
+TargetAsmInfo::SectionKindForGlobal(const GlobalValue *GV) const {
+ // Early exit - functions should be always in text sections.
+ if (isa<Function>(GV))
+ return SectionKind::Text;
+
+ const GlobalVariable* GVar = dyn_cast<GlobalVariable>(GV);
+ bool isThreadLocal = GVar->isThreadLocal();
+ assert(GVar && "Invalid global value for section selection");
+
+ if (isSuitableForBSS(GVar)) {
+ // Variable can be easily put to BSS section.
+ return (isThreadLocal ? SectionKind::ThreadBSS : SectionKind::BSS);
+ } else if (GVar->isConstant() && !isThreadLocal) {
+ // Now we know, that varible has initializer and it is constant. We need to
+ // check its initializer to decide, which section to output it into. Also
+ // note, there is no thread-local r/o section.
+ Constant *C = GVar->getInitializer();
+ if (C->ContainsRelocations(Reloc::LocalOrGlobal)) {
+ // Decide, whether it is still possible to put symbol into r/o section.
+ unsigned Reloc = RelocBehaviour();
+
+ // We already did a query for 'all' relocs, thus - early exits.
+ if (Reloc == Reloc::LocalOrGlobal)
+ return SectionKind::Data;
+ else if (Reloc == Reloc::None)
+ return SectionKind::ROData;
+ else {
+ // Ok, target wants something funny. Honour it.
+ return (C->ContainsRelocations(Reloc) ?
+ SectionKind::Data : SectionKind::ROData);
+ }
+ } else {
+ // Check, if initializer is a null-terminated string
+ if (isConstantString(C))
+ return SectionKind::RODataMergeStr;
+ else
+ return SectionKind::RODataMergeConst;
+ }
+ }
+
+ // Variable either is not constant or thread-local - output to data section.
+ return (isThreadLocal ? SectionKind::ThreadData : SectionKind::Data);
+}
+
+unsigned
+TargetAsmInfo::SectionFlagsForGlobal(const GlobalValue *GV,
+ const char* Name) const {
+ unsigned Flags = SectionFlags::None;
+
+ // Decode flags from global itself.
+ if (GV) {
+ SectionKind::Kind Kind = SectionKindForGlobal(GV);
+ 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;
+ case SectionKind::SmallData:
+ case SectionKind::SmallBSS:
+ Flags |= SectionFlags::Writeable;
+ // FALLS THROUGH
+ case SectionKind::SmallROData:
+ Flags |= SectionFlags::Small;
+ break;
+ default:
+ assert(0 && "Unexpected section kind!");
+ }
+
+ if (GV->isWeakForLinker())
+ Flags |= SectionFlags::Linkonce;
+ }
+
+ // Add flags from sections, if any.
+ if (Name && *Name) {
+ Flags |= SectionFlags::Named;
+
+ // Some lame default implementation based on some magic section names.
+ if (strncmp(Name, ".gnu.linkonce.b.", 16) == 0 ||
+ strncmp(Name, ".llvm.linkonce.b.", 17) == 0 ||
+ strncmp(Name, ".gnu.linkonce.sb.", 17) == 0 ||
+ strncmp(Name, ".llvm.linkonce.sb.", 18) == 0)
+ Flags |= SectionFlags::BSS;
+ else if (strcmp(Name, ".tdata") == 0 ||
+ strncmp(Name, ".tdata.", 7) == 0 ||
+ strncmp(Name, ".gnu.linkonce.td.", 17) == 0 ||
+ strncmp(Name, ".llvm.linkonce.td.", 18) == 0)
+ Flags |= SectionFlags::TLS;
+ else if (strcmp(Name, ".tbss") == 0 ||
+ strncmp(Name, ".tbss.", 6) == 0 ||
+ strncmp(Name, ".gnu.linkonce.tb.", 17) == 0 ||
+ strncmp(Name, ".llvm.linkonce.tb.", 18) == 0)
+ Flags |= SectionFlags::BSS | SectionFlags::TLS;
+ }
+
+ return Flags;
+}
+
+const Section*
+TargetAsmInfo::SectionForGlobal(const GlobalValue *GV) const {
+ const Section* S;
+ // Select section name
+ if (GV->hasSection()) {
+ // Honour section already set, if any
+ unsigned Flags = SectionFlagsForGlobal(GV,
+ GV->getSection().c_str());
+ S = getNamedSection(GV->getSection().c_str(), Flags);
+ } else {
+ // Use default section depending on the 'type' of global
+ S = SelectSectionForGlobal(GV);
+ }
+
+ return S;
+}
+
+// Lame default implementation. Calculate the section name for global.
+const Section*
+TargetAsmInfo::SelectSectionForGlobal(const GlobalValue *GV) const {
+ SectionKind::Kind Kind = SectionKindForGlobal(GV);
+
+ if (GV->isWeakForLinker()) {
+ std::string Name = UniqueSectionForGlobal(GV, Kind);
+ unsigned Flags = SectionFlagsForGlobal(GV, Name.c_str());
+ return getNamedSection(Name.c_str(), Flags);
+ } else {
+ if (Kind == SectionKind::Text)
+ return getTextSection();
+ else if (isBSS(Kind) && getBSSSection_())
+ return getBSSSection_();
+ else if (getReadOnlySection() && SectionKind::isReadOnly(Kind))
+ return getReadOnlySection();
+ }
+
+ return getDataSection();
+}
+
+// Lame default implementation. Calculate the section name for machine const.
+const Section*
+TargetAsmInfo::SelectSectionForMachineConst(const Type *Ty) const {
+ // FIXME: Support data.rel stuff someday
+ return getDataSection();
+}
+
+std::string
+TargetAsmInfo::UniqueSectionForGlobal(const GlobalValue* GV,
+ SectionKind::Kind Kind) const {
+ switch (Kind) {
+ case SectionKind::Text:
+ return ".gnu.linkonce.t." + GV->getName();
+ case SectionKind::Data:
+ return ".gnu.linkonce.d." + GV->getName();
+ case SectionKind::DataRel:
+ return ".gnu.linkonce.d.rel" + GV->getName();
+ case SectionKind::DataRelLocal:
+ return ".gnu.linkonce.d.rel.local" + GV->getName();
+ case SectionKind::DataRelRO:
+ return ".gnu.linkonce.d.rel.ro" + GV->getName();
+ case SectionKind::DataRelROLocal:
+ return ".gnu.linkonce.d.rel.ro.local" + GV->getName();
+ case SectionKind::SmallData:
+ return ".gnu.linkonce.s." + GV->getName();
+ case SectionKind::BSS:
+ return ".gnu.linkonce.b." + GV->getName();
+ case SectionKind::SmallBSS:
+ return ".gnu.linkonce.sb." + GV->getName();
+ case SectionKind::ROData:
+ case SectionKind::RODataMergeConst:
+ case SectionKind::RODataMergeStr:
+ return ".gnu.linkonce.r." + GV->getName();
+ case SectionKind::SmallROData:
+ return ".gnu.linkonce.s2." + GV->getName();
+ case SectionKind::ThreadData:
+ return ".gnu.linkonce.td." + GV->getName();
+ case SectionKind::ThreadBSS:
+ return ".gnu.linkonce.tb." + GV->getName();
+ default:
+ assert(0 && "Unknown section kind");
+ }
+ return NULL;
+}
+
+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;
+}
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