| //===-- llvm/MC/MCAsmInfo.h - Asm info --------------------------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file contains a class to be used as the basis for target specific |
| // asm writers. This class primarily takes care of global printing constants, |
| // which are used in very similar ways across all targets. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_MC_MCASMINFO_H |
| #define LLVM_MC_MCASMINFO_H |
| |
| #include "llvm/MC/MCDirectives.h" |
| #include "llvm/MC/MCDwarf.h" |
| #include "llvm/MC/MachineLocation.h" |
| #include <cassert> |
| #include <vector> |
| |
| namespace llvm { |
| class MCExpr; |
| class MCSection; |
| class MCStreamer; |
| class MCSymbol; |
| class MCContext; |
| |
| namespace WinEH { |
| enum class EncodingType { |
| ET_Invalid, /// Invalid |
| ET_Alpha, /// Windows Alpha |
| ET_Alpha64, /// Windows AXP64 |
| ET_ARM, /// Windows NT (Windows on ARM) |
| ET_CE, /// Windows CE ARM, PowerPC, SH3, SH4 |
| ET_Itanium, /// Windows x64, Windows Itanium (IA-64) |
| ET_MIPS = ET_Alpha, |
| }; |
| } |
| |
| enum class ExceptionHandling { |
| None, /// No exception support |
| DwarfCFI, /// DWARF-like instruction based exceptions |
| SjLj, /// setjmp/longjmp based exceptions |
| ARM, /// ARM EHABI |
| WinEH, /// Windows Exception Handling |
| }; |
| |
| namespace LCOMM { |
| enum LCOMMType { NoAlignment, ByteAlignment, Log2Alignment }; |
| } |
| |
| /// This class is intended to be used as a base class for asm |
| /// properties and features specific to the target. |
| class MCAsmInfo { |
| protected: |
| //===------------------------------------------------------------------===// |
| // Properties to be set by the target writer, used to configure asm printer. |
| // |
| |
| /// Pointer size in bytes. Default is 4. |
| unsigned PointerSize; |
| |
| /// Size of the stack slot reserved for callee-saved registers, in bytes. |
| /// Default is same as pointer size. |
| unsigned CalleeSaveStackSlotSize; |
| |
| /// True if target is little endian. Default is true. |
| bool IsLittleEndian; |
| |
| /// True if target stack grow up. Default is false. |
| bool StackGrowsUp; |
| |
| /// True if this target has the MachO .subsections_via_symbols directive. |
| /// Default is false. |
| bool HasSubsectionsViaSymbols; |
| |
| /// True if this is a MachO target that supports the macho-specific .zerofill |
| /// directive for emitting BSS Symbols. Default is false. |
| bool HasMachoZeroFillDirective; |
| |
| /// True if this is a MachO target that supports the macho-specific .tbss |
| /// directive for emitting thread local BSS Symbols. Default is false. |
| bool HasMachoTBSSDirective; |
| |
| /// True if the compiler should emit a ".reference .constructors_used" or |
| /// ".reference .destructors_used" directive after the a static ctor/dtor |
| /// list. This directive is only emitted in Static relocation model. Default |
| /// is false. |
| bool HasStaticCtorDtorReferenceInStaticMode; |
| |
| /// True if the linker has a bug and requires that the debug_line section be |
| /// of a minimum size. In practice such a linker requires a non-empty line |
| /// sequence if a file is present. Default to false. |
| bool LinkerRequiresNonEmptyDwarfLines; |
| |
| /// This is the maximum possible length of an instruction, which is needed to |
| /// compute the size of an inline asm. Defaults to 4. |
| unsigned MaxInstLength; |
| |
| /// Every possible instruction length is a multiple of this value. Factored |
| /// out in .debug_frame and .debug_line. Defaults to 1. |
| unsigned MinInstAlignment; |
| |
| /// The '$' token, when not referencing an identifier or constant, refers to |
| /// the current PC. Defaults to false. |
| bool DollarIsPC; |
| |
| /// This string, if specified, is used to separate instructions from each |
| /// other when on the same line. Defaults to ';' |
| const char *SeparatorString; |
| |
| /// This indicates the comment character used by the assembler. Defaults to |
| /// "#" |
| const char *CommentString; |
| |
| /// This is appended to emitted labels. Defaults to ":" |
| const char *LabelSuffix; |
| |
| // Print the EH begin symbol with an assignment. Defaults to false. |
| bool UseAssignmentForEHBegin; |
| |
| /// This prefix is used for globals like constant pool entries that are |
| /// completely private to the .s file and should not have names in the .o |
| /// file. Defaults to "L" |
| const char *PrivateGlobalPrefix; |
| |
| /// This prefix is used for symbols that should be passed through the |
| /// assembler but be removed by the linker. This is 'l' on Darwin, currently |
| /// used for some ObjC metadata. The default of "" meast that for this system |
| /// a plain private symbol should be used. Defaults to "". |
| const char *LinkerPrivateGlobalPrefix; |
| |
| /// If these are nonempty, they contain a directive to emit before and after |
| /// an inline assembly statement. Defaults to "#APP\n", "#NO_APP\n" |
| const char *InlineAsmStart; |
| const char *InlineAsmEnd; |
| |
| /// These are assembly directives that tells the assembler to interpret the |
| /// following instructions differently. Defaults to ".code16", ".code32", |
| /// ".code64". |
| const char *Code16Directive; |
| const char *Code32Directive; |
| const char *Code64Directive; |
| |
| /// Which dialect of an assembler variant to use. Defaults to 0 |
| unsigned AssemblerDialect; |
| |
| /// This is true if the assembler allows @ characters in symbol names. |
| /// Defaults to false. |
| bool AllowAtInName; |
| |
| /// This is true if data region markers should be printed as |
| /// ".data_region/.end_data_region" directives. If false, use "$d/$a" labels |
| /// instead. |
| bool UseDataRegionDirectives; |
| |
| //===--- Data Emission Directives -------------------------------------===// |
| |
| /// This should be set to the directive used to get some number of zero bytes |
| /// emitted to the current section. Common cases are "\t.zero\t" and |
| /// "\t.space\t". If this is set to null, the Data*bitsDirective's will be |
| /// used to emit zero bytes. Defaults to "\t.zero\t" |
| const char *ZeroDirective; |
| |
| /// This directive allows emission of an ascii string with the standard C |
| /// escape characters embedded into it. Defaults to "\t.ascii\t" |
| const char *AsciiDirective; |
| |
| /// If not null, this allows for special handling of zero terminated strings |
| /// on this target. This is commonly supported as ".asciz". If a target |
| /// doesn't support this, it can be set to null. Defaults to "\t.asciz\t" |
| const char *AscizDirective; |
| |
| /// These directives are used to output some unit of integer data to the |
| /// current section. If a data directive is set to null, smaller data |
| /// directives will be used to emit the large sizes. Defaults to "\t.byte\t", |
| /// "\t.short\t", "\t.long\t", "\t.quad\t" |
| const char *Data8bitsDirective; |
| const char *Data16bitsDirective; |
| const char *Data32bitsDirective; |
| const char *Data64bitsDirective; |
| |
| /// If non-null, a directive that is used to emit a word which should be |
| /// relocated as a 64-bit GP-relative offset, e.g. .gpdword on Mips. Defaults |
| /// to NULL. |
| const char *GPRel64Directive; |
| |
| /// If non-null, a directive that is used to emit a word which should be |
| /// relocated as a 32-bit GP-relative offset, e.g. .gpword on Mips or .gprel32 |
| /// on Alpha. Defaults to NULL. |
| const char *GPRel32Directive; |
| |
| /// This is true if this target uses "Sun Style" syntax for section switching |
| /// ("#alloc,#write" etc) instead of the normal ELF syntax (,"a,w") in |
| /// .section directives. Defaults to false. |
| bool SunStyleELFSectionSwitchSyntax; |
| |
| /// This is true if this target uses ELF '.section' directive before the |
| /// '.bss' one. It's used for PPC/Linux which doesn't support the '.bss' |
| /// directive only. Defaults to false. |
| bool UsesELFSectionDirectiveForBSS; |
| |
| bool NeedsDwarfSectionOffsetDirective; |
| |
| //===--- Alignment Information ----------------------------------------===// |
| |
| /// If this is true (the default) then the asmprinter emits ".align N" |
| /// directives, where N is the number of bytes to align to. Otherwise, it |
| /// emits ".align log2(N)", e.g. 3 to align to an 8 byte boundary. Defaults |
| /// to true. |
| bool AlignmentIsInBytes; |
| |
| /// If non-zero, this is used to fill the executable space created as the |
| /// result of a alignment directive. Defaults to 0 |
| unsigned TextAlignFillValue; |
| |
| //===--- Global Variable Emission Directives --------------------------===// |
| |
| /// This is the directive used to declare a global entity. Defaults to NULL. |
| const char *GlobalDirective; |
| |
| /// True if the assembler supports the .set directive. Defaults to true. |
| bool HasSetDirective; |
| |
| /// False if the assembler requires that we use |
| /// \code |
| /// Lc = a - b |
| /// .long Lc |
| /// \endcode |
| // |
| /// instead of |
| // |
| /// \code |
| /// .long a - b |
| /// \endcode |
| /// |
| /// Defaults to true. |
| bool HasAggressiveSymbolFolding; |
| |
| /// True is .comm's and .lcomms optional alignment is to be specified in bytes |
| /// instead of log2(n). Defaults to true. |
| bool COMMDirectiveAlignmentIsInBytes; |
| |
| /// Describes if the .lcomm directive for the target supports an alignment |
| /// argument and how it is interpreted. Defaults to NoAlignment. |
| LCOMM::LCOMMType LCOMMDirectiveAlignmentType; |
| |
| /// True if the target has .type and .size directives, this is true for most |
| /// ELF targets. Defaults to true. |
| bool HasDotTypeDotSizeDirective; |
| |
| /// True if the target has a single parameter .file directive, this is true |
| /// for ELF targets. Defaults to true. |
| bool HasSingleParameterDotFile; |
| |
| /// True if the target has a .ident directive, this is true for ELF targets. |
| /// Defaults to false. |
| bool HasIdentDirective; |
| |
| /// True if this target supports the MachO .no_dead_strip directive. Defaults |
| /// to false. |
| bool HasNoDeadStrip; |
| |
| /// This directive, if non-null, is used to declare a global as being a weak |
| /// undefined symbol. Defaults to NULL. |
| const char *WeakRefDirective; |
| |
| /// True if we have a directive to declare a global as being a weak defined |
| /// symbol. Defaults to false. |
| bool HasWeakDefDirective; |
| |
| /// True if we have a directive to declare a global as being a weak defined |
| /// symbol that can be hidden (unexported). Defaults to false. |
| bool HasWeakDefCanBeHiddenDirective; |
| |
| /// True if we have a .linkonce directive. This is used on cygwin/mingw. |
| /// Defaults to false. |
| bool HasLinkOnceDirective; |
| |
| /// This attribute, if not MCSA_Invalid, is used to declare a symbol as having |
| /// hidden visibility. Defaults to MCSA_Hidden. |
| MCSymbolAttr HiddenVisibilityAttr; |
| |
| /// This attribute, if not MCSA_Invalid, is used to declare an undefined |
| /// symbol as having hidden visibility. Defaults to MCSA_Hidden. |
| MCSymbolAttr HiddenDeclarationVisibilityAttr; |
| |
| /// This attribute, if not MCSA_Invalid, is used to declare a symbol as having |
| /// protected visibility. Defaults to MCSA_Protected |
| MCSymbolAttr ProtectedVisibilityAttr; |
| |
| //===--- Dwarf Emission Directives -----------------------------------===// |
| |
| /// True if target asm supports leb128 directives. Defaults to false. |
| bool HasLEB128; |
| |
| /// True if target supports emission of debugging information. Defaults to |
| /// false. |
| bool SupportsDebugInformation; |
| |
| /// Exception handling format for the target. Defaults to None. |
| ExceptionHandling ExceptionsType; |
| |
| /// Windows exception handling data (.pdata) encoding. Defaults to Invalid. |
| WinEH::EncodingType WinEHEncodingType; |
| |
| /// True if Dwarf2 output generally uses relocations for references to other |
| /// .debug_* sections. |
| bool DwarfUsesRelocationsAcrossSections; |
| |
| /// True if DWARF FDE symbol reference relocations should be replaced by an |
| /// absolute difference. |
| bool DwarfFDESymbolsUseAbsDiff; |
| |
| /// True if dwarf register numbers are printed instead of symbolic register |
| /// names in .cfi_* directives. Defaults to false. |
| bool DwarfRegNumForCFI; |
| |
| /// True if target uses parens to indicate the symbol variant instead of @. |
| /// For example, foo(plt) instead of foo@plt. Defaults to false. |
| bool UseParensForSymbolVariant; |
| |
| //===--- Prologue State ----------------------------------------------===// |
| |
| std::vector<MCCFIInstruction> InitialFrameState; |
| |
| //===--- Integrated Assembler State ----------------------------------===// |
| |
| /// Should we use the integrated assembler? |
| /// The integrated assembler should be enabled by default (by the |
| /// constructors) when failing to parse a valid piece of assembly (inline |
| /// or otherwise) is considered a bug. It may then be overridden after |
| /// construction (see LLVMTargetMachine::initAsmInfo()). |
| bool UseIntegratedAssembler; |
| |
| /// Compress DWARF debug sections. Defaults to false. |
| bool CompressDebugSections; |
| |
| public: |
| explicit MCAsmInfo(); |
| virtual ~MCAsmInfo(); |
| |
| /// Get the pointer size in bytes. |
| unsigned getPointerSize() const { return PointerSize; } |
| |
| /// Get the callee-saved register stack slot |
| /// size in bytes. |
| unsigned getCalleeSaveStackSlotSize() const { |
| return CalleeSaveStackSlotSize; |
| } |
| |
| /// True if the target is little endian. |
| bool isLittleEndian() const { return IsLittleEndian; } |
| |
| /// True if target stack grow up. |
| bool isStackGrowthDirectionUp() const { return StackGrowsUp; } |
| |
| bool hasSubsectionsViaSymbols() const { return HasSubsectionsViaSymbols; } |
| |
| // Data directive accessors. |
| |
| const char *getData8bitsDirective() const { return Data8bitsDirective; } |
| const char *getData16bitsDirective() const { return Data16bitsDirective; } |
| const char *getData32bitsDirective() const { return Data32bitsDirective; } |
| const char *getData64bitsDirective() const { return Data64bitsDirective; } |
| const char *getGPRel64Directive() const { return GPRel64Directive; } |
| const char *getGPRel32Directive() const { return GPRel32Directive; } |
| |
| /// Targets can implement this method to specify a section to switch to if the |
| /// translation unit doesn't have any trampolines that require an executable |
| /// stack. |
| virtual const MCSection *getNonexecutableStackSection(MCContext &Ctx) const { |
| return nullptr; |
| } |
| |
| virtual const MCExpr *getExprForPersonalitySymbol(const MCSymbol *Sym, |
| unsigned Encoding, |
| MCStreamer &Streamer) const; |
| |
| virtual const MCExpr *getExprForFDESymbol(const MCSymbol *Sym, |
| unsigned Encoding, |
| MCStreamer &Streamer) const; |
| |
| bool usesSunStyleELFSectionSwitchSyntax() const { |
| return SunStyleELFSectionSwitchSyntax; |
| } |
| |
| bool usesELFSectionDirectiveForBSS() const { |
| return UsesELFSectionDirectiveForBSS; |
| } |
| |
| bool needsDwarfSectionOffsetDirective() const { |
| return NeedsDwarfSectionOffsetDirective; |
| } |
| |
| // Accessors. |
| |
| bool hasMachoZeroFillDirective() const { return HasMachoZeroFillDirective; } |
| bool hasMachoTBSSDirective() const { return HasMachoTBSSDirective; } |
| bool hasStaticCtorDtorReferenceInStaticMode() const { |
| return HasStaticCtorDtorReferenceInStaticMode; |
| } |
| bool getLinkerRequiresNonEmptyDwarfLines() const { |
| return LinkerRequiresNonEmptyDwarfLines; |
| } |
| unsigned getMaxInstLength() const { return MaxInstLength; } |
| unsigned getMinInstAlignment() const { return MinInstAlignment; } |
| bool getDollarIsPC() const { return DollarIsPC; } |
| const char *getSeparatorString() const { return SeparatorString; } |
| |
| /// This indicates the column (zero-based) at which asm comments should be |
| /// printed. |
| unsigned getCommentColumn() const { return 40; } |
| |
| const char *getCommentString() const { return CommentString; } |
| const char *getLabelSuffix() const { return LabelSuffix; } |
| |
| bool useAssignmentForEHBegin() const { return UseAssignmentForEHBegin; } |
| const char *getPrivateGlobalPrefix() const { return PrivateGlobalPrefix; } |
| bool hasLinkerPrivateGlobalPrefix() const { |
| return LinkerPrivateGlobalPrefix[0] != '\0'; |
| } |
| const char *getLinkerPrivateGlobalPrefix() const { |
| if (hasLinkerPrivateGlobalPrefix()) |
| return LinkerPrivateGlobalPrefix; |
| return getPrivateGlobalPrefix(); |
| } |
| const char *getInlineAsmStart() const { return InlineAsmStart; } |
| const char *getInlineAsmEnd() const { return InlineAsmEnd; } |
| const char *getCode16Directive() const { return Code16Directive; } |
| const char *getCode32Directive() const { return Code32Directive; } |
| const char *getCode64Directive() const { return Code64Directive; } |
| unsigned getAssemblerDialect() const { return AssemblerDialect; } |
| bool doesAllowAtInName() const { return AllowAtInName; } |
| bool doesSupportDataRegionDirectives() const { |
| return UseDataRegionDirectives; |
| } |
| const char *getZeroDirective() const { return ZeroDirective; } |
| const char *getAsciiDirective() const { return AsciiDirective; } |
| const char *getAscizDirective() const { return AscizDirective; } |
| bool getAlignmentIsInBytes() const { return AlignmentIsInBytes; } |
| unsigned getTextAlignFillValue() const { return TextAlignFillValue; } |
| const char *getGlobalDirective() const { return GlobalDirective; } |
| bool hasSetDirective() const { return HasSetDirective; } |
| bool hasAggressiveSymbolFolding() const { return HasAggressiveSymbolFolding; } |
| bool getCOMMDirectiveAlignmentIsInBytes() const { |
| return COMMDirectiveAlignmentIsInBytes; |
| } |
| LCOMM::LCOMMType getLCOMMDirectiveAlignmentType() const { |
| return LCOMMDirectiveAlignmentType; |
| } |
| bool hasDotTypeDotSizeDirective() const { return HasDotTypeDotSizeDirective; } |
| bool hasSingleParameterDotFile() const { return HasSingleParameterDotFile; } |
| bool hasIdentDirective() const { return HasIdentDirective; } |
| bool hasNoDeadStrip() const { return HasNoDeadStrip; } |
| const char *getWeakRefDirective() const { return WeakRefDirective; } |
| bool hasWeakDefDirective() const { return HasWeakDefDirective; } |
| bool hasWeakDefCanBeHiddenDirective() const { |
| return HasWeakDefCanBeHiddenDirective; |
| } |
| bool hasLinkOnceDirective() const { return HasLinkOnceDirective; } |
| |
| MCSymbolAttr getHiddenVisibilityAttr() const { return HiddenVisibilityAttr; } |
| MCSymbolAttr getHiddenDeclarationVisibilityAttr() const { |
| return HiddenDeclarationVisibilityAttr; |
| } |
| MCSymbolAttr getProtectedVisibilityAttr() const { |
| return ProtectedVisibilityAttr; |
| } |
| bool hasLEB128() const { return HasLEB128; } |
| bool doesSupportDebugInformation() const { return SupportsDebugInformation; } |
| bool doesSupportExceptionHandling() const { |
| return ExceptionsType != ExceptionHandling::None; |
| } |
| ExceptionHandling getExceptionHandlingType() const { return ExceptionsType; } |
| WinEH::EncodingType getWinEHEncodingType() const { return WinEHEncodingType; } |
| bool isExceptionHandlingDwarf() const { |
| return (ExceptionsType == ExceptionHandling::DwarfCFI || |
| ExceptionsType == ExceptionHandling::ARM || |
| // Windows handler data still uses DWARF LSDA encoding. |
| ExceptionsType == ExceptionHandling::WinEH); |
| } |
| bool doesDwarfUseRelocationsAcrossSections() const { |
| return DwarfUsesRelocationsAcrossSections; |
| } |
| bool doDwarfFDESymbolsUseAbsDiff() const { return DwarfFDESymbolsUseAbsDiff; } |
| bool useDwarfRegNumForCFI() const { return DwarfRegNumForCFI; } |
| bool useParensForSymbolVariant() const { return UseParensForSymbolVariant; } |
| |
| void addInitialFrameState(const MCCFIInstruction &Inst) { |
| InitialFrameState.push_back(Inst); |
| } |
| |
| const std::vector<MCCFIInstruction> &getInitialFrameState() const { |
| return InitialFrameState; |
| } |
| |
| /// Return true if assembly (inline or otherwise) should be parsed. |
| bool useIntegratedAssembler() const { return UseIntegratedAssembler; } |
| |
| /// Set whether assembly (inline or otherwise) should be parsed. |
| virtual void setUseIntegratedAssembler(bool Value) { |
| UseIntegratedAssembler = Value; |
| } |
| |
| bool compressDebugSections() const { return CompressDebugSections; } |
| |
| void setCompressDebugSections(bool CompressDebugSections) { |
| this->CompressDebugSections = CompressDebugSections; |
| } |
| }; |
| } |
| |
| #endif |