llvm-6502/include/llvm/MC/MCAsmInfo.h

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//===-- 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 ExceptionHandling {
enum ExceptionsType { None, DwarfCFI, SjLj, ARM, Win64 };
}
namespace LCOMM {
enum LCOMMType { NoAlignment, ByteAlignment, Log2Alignment };
}
/// MCAsmInfo - 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.
//
/// PointerSize - Pointer size in bytes.
/// Default is 4.
unsigned PointerSize;
/// CalleeSaveStackSlotSize - Size of the stack slot reserved for
/// callee-saved registers, in bytes.
/// Default is same as pointer size.
unsigned CalleeSaveStackSlotSize;
/// IsLittleEndian - True if target is little endian.
/// Default is true.
bool IsLittleEndian;
/// StackGrowsUp - True if target stack grow up.
/// Default is false.
bool StackGrowsUp;
/// HasSubsectionsViaSymbols - True if this target has the MachO
/// .subsections_via_symbols directive.
bool HasSubsectionsViaSymbols; // Default is false.
/// HasMachoZeroFillDirective - True if this is a MachO target that supports
/// the macho-specific .zerofill directive for emitting BSS Symbols.
bool HasMachoZeroFillDirective; // Default is false.
/// HasMachoTBSSDirective - True if this is a MachO target that supports
/// the macho-specific .tbss directive for emitting thread local BSS Symbols
bool HasMachoTBSSDirective; // Default is false.
/// HasStaticCtorDtorReferenceInStaticMode - 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.
bool HasStaticCtorDtorReferenceInStaticMode; // Default is false.
/// LinkerRequiresNonEmptyDwarfLines - 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.
bool LinkerRequiresNonEmptyDwarfLines; // Default to false.
/// MaxInstLength - This is the maximum possible length of an instruction,
/// which is needed to compute the size of an inline asm.
unsigned MaxInstLength; // Defaults to 4.
/// MinInstAlignment - Every possible instruction length is a multiple of
/// this value. Factored out in .debug_frame and .debug_line.
unsigned MinInstAlignment; // Defaults to 1.
/// DollarIsPC - The '$' token, when not referencing an identifier or
/// constant, refers to the current PC.
bool DollarIsPC; // Defaults to false.
/// SeparatorString - This string, if specified, is used to separate
/// instructions from each other when on the same line.
const char *SeparatorString; // Defaults to ';'
/// CommentColumn - This indicates the comment num (zero-based) at
/// which asm comments should be printed.
unsigned CommentColumn; // Defaults to 40
/// CommentString - This indicates the comment character used by the
/// assembler.
const char *CommentString; // Defaults to "#"
/// LabelSuffix - This is appended to emitted labels.
const char *LabelSuffix; // Defaults to ":"
This patch is needed to make c++ exceptions work for mips16. Mips16 is really a processor decoding mode (ala thumb 1) and in the same program, mips16 and mips32 functions can exist and can call each other. If a jal type instruction encounters an address with the lower bit set, then the processor switches to mips16 mode (if it is not already in it). If the lower bit is not set, then it switches to mips32 mode. The linker knows which functions are mips16 and which are mips32. When relocation is performed on code labels, this lower order bit is set if the code label is a mips16 code label. In general this works just fine, however when creating exception handling tables and dwarf, there are cases where you don't want this lower order bit added in. This has been traditionally distinguished in gas assembly source by using a different syntax for the label. lab1: ; this will cause the lower order bit to be added lab2=. ; this will not cause the lower order bit to be added In some cases, it does not matter because in dwarf and debug tables the difference of two labels is used and in that case the lower order bits subtract each other out. To fix this, I have added to mcstreamer the notion of a debuglabel. The default is for label and debug label to be the same. So calling EmitLabel and EmitDebugLabel produce the same result. For various reasons, there is only one set of labels that needs to be modified for the mips exceptions to work. These are the "$eh_func_beginXXX" labels. Mips overrides the debug label suffix from ":" to "=." . This initial patch fixes exceptions. More changes most likely will be needed to DwarfCFException to make all of this work for actual debugging. These changes will be to emit debug labels in some places where a simple label is emitted now. Some historical discussion on this from gcc can be found at: http://gcc.gnu.org/ml/gcc-patches/2008-08/msg00623.html http://gcc.gnu.org/ml/gcc-patches/2008-11/msg01273.html git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170279 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-16 04:00:45 +00:00
/// LabelSuffix - This is appended to emitted labels.
const char *DebugLabelSuffix; // Defaults to ":"
/// If this is set to anything other than '\0', it is prepended
/// onto all global symbols. This is often used for '_'.
char GlobalPrefix; // Defaults to '\0'
/// 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.
const char *PrivateGlobalPrefix; // Defaults to "L"
/// 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.
const char *LinkerPrivateGlobalPrefix; // Defaults to "".
/// InlineAsmStart/End - If these are nonempty, they contain a directive to
/// emit before and after an inline assembly statement.
const char *InlineAsmStart; // Defaults to "#APP\n"
const char *InlineAsmEnd; // Defaults to "#NO_APP\n"
/// Code16Directive, Code32Directive, Code64Directive - These are assembly
/// directives that tells the assembler to interpret the following
/// instructions differently.
const char *Code16Directive; // Defaults to ".code16"
const char *Code32Directive; // Defaults to ".code32"
const char *Code64Directive; // Defaults to ".code64"
/// AssemblerDialect - Which dialect of an assembler variant to use.
unsigned AssemblerDialect; // Defaults to 0
/// \brief This is true if the assembler allows @ characters in symbol
/// names. Defaults to false.
bool AllowAtInName;
/// UseDataRegionDirectives - 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 -------------------------------------===//
/// ZeroDirective - 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.
const char *ZeroDirective; // Defaults to "\t.zero\t"
/// AsciiDirective - This directive allows emission of an ascii string with
/// the standard C escape characters embedded into it.
const char *AsciiDirective; // Defaults to "\t.ascii\t"
/// AscizDirective - 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.
const char *AscizDirective; // Defaults to "\t.asciz\t"
/// DataDirectives - 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.
const char *Data8bitsDirective; // Defaults to "\t.byte\t"
const char *Data16bitsDirective; // Defaults to "\t.short\t"
const char *Data32bitsDirective; // Defaults to "\t.long\t"
const char *Data64bitsDirective; // Defaults to "\t.quad\t"
/// GPRel64Directive - 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.
const char *GPRel64Directive; // Defaults to NULL.
/// GPRel32Directive - 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.
const char *GPRel32Directive; // Defaults to NULL.
/// SunStyleELFSectionSwitchSyntax - 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.
bool SunStyleELFSectionSwitchSyntax; // Defaults to false.
/// UsesELFSectionDirectiveForBSS - 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.
bool UsesELFSectionDirectiveForBSS; // Defaults to false.
/// HasMicrosoftFastStdCallMangling - True if this target uses microsoft
/// style mangling for functions with X86_StdCall/X86_FastCall calling
/// convention.
bool HasMicrosoftFastStdCallMangling; // Defaults to false.
bool NeedsDwarfSectionOffsetDirective;
//===--- Alignment Information ----------------------------------------===//
/// AlignDirective - The directive used to emit round up to an alignment
/// boundary.
///
const char *AlignDirective; // Defaults to "\t.align\t"
/// AlignmentIsInBytes - 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.
bool AlignmentIsInBytes; // Defaults to true
/// TextAlignFillValue - If non-zero, this is used to fill the executable
/// space created as the result of a alignment directive.
unsigned TextAlignFillValue; // Defaults to 0
//===--- Global Variable Emission Directives --------------------------===//
/// GlobalDirective - This is the directive used to declare a global entity.
///
const char *GlobalDirective; // Defaults to NULL.
/// HasSetDirective - True if the assembler supports the .set directive.
bool HasSetDirective; // Defaults to true.
/// HasAggressiveSymbolFolding - False if the assembler requires that we use
/// Lc = a - b
/// .long Lc
/// instead of
/// .long a - b
bool HasAggressiveSymbolFolding; // Defaults to true.
/// COMMDirectiveAlignmentIsInBytes - True is .comm's and .lcomms optional
/// alignment is to be specified in bytes instead of log2(n).
bool COMMDirectiveAlignmentIsInBytes; // Defaults to true;
/// LCOMMDirectiveAlignment - Describes if the .lcomm directive for the
/// target supports an alignment argument and how it is interpreted.
LCOMM::LCOMMType LCOMMDirectiveAlignmentType; // Defaults to NoAlignment.
/// HasDotTypeDotSizeDirective - True if the target has .type and .size
/// directives, this is true for most ELF targets.
bool HasDotTypeDotSizeDirective; // Defaults to true.
/// HasSingleParameterDotFile - True if the target has a single parameter
/// .file directive, this is true for ELF targets.
bool HasSingleParameterDotFile; // Defaults to true.
/// hasIdentDirective - True if the target has a .ident directive, this is
/// true for ELF targets.
bool HasIdentDirective; // Defaults to false.
/// HasNoDeadStrip - True if this target supports the MachO .no_dead_strip
/// directive.
bool HasNoDeadStrip; // Defaults to false.
/// WeakRefDirective - This directive, if non-null, is used to declare a
/// global as being a weak undefined symbol.
const char *WeakRefDirective; // Defaults to NULL.
/// True if we have a directive to declare a global as being a weak
/// defined symbol.
bool HasWeakDefDirective; // Defaults to false.
/// True if we have a directive to declare a global as being a weak
/// defined symbol that can be hidden (unexported).
bool HasWeakDefCanBeHiddenDirective; // Defaults to false.
/// True if we have a .linkonce directive. This is used on cygwin/mingw.
bool HasLinkOnceDirective; // Defaults to false.
/// HiddenVisibilityAttr - This attribute, if not MCSA_Invalid, is used to
/// declare a symbol as having hidden visibility.
MCSymbolAttr HiddenVisibilityAttr; // Defaults to MCSA_Hidden.
/// HiddenDeclarationVisibilityAttr - This attribute, if not MCSA_Invalid,
/// is used to declare an undefined symbol as having hidden visibility.
MCSymbolAttr HiddenDeclarationVisibilityAttr; // Defaults to MCSA_Hidden.
/// ProtectedVisibilityAttr - This attribute, if not MCSA_Invalid, is used
/// to declare a symbol as having protected visibility.
MCSymbolAttr ProtectedVisibilityAttr; // Defaults to MCSA_Protected
//===--- Dwarf Emission Directives -----------------------------------===//
/// HasLEB128 - True if target asm supports leb128 directives.
bool HasLEB128; // Defaults to false.
/// SupportsDebugInformation - True if target supports emission of debugging
/// information.
bool SupportsDebugInformation; // Defaults to false.
/// SupportsExceptionHandling - True if target supports exception handling.
ExceptionHandling::ExceptionsType ExceptionsType; // Defaults to None
/// DwarfUsesRelocationsAcrossSections - True if Dwarf2 output generally
/// uses relocations for references to other .debug_* sections.
bool DwarfUsesRelocationsAcrossSections;
/// DwarfRegNumForCFI - True if dwarf register numbers are printed
/// instead of symbolic register names in .cfi_* directives.
bool DwarfRegNumForCFI; // Defaults to false;
/// UseParensForSymbolVariant - True if target uses parens to indicate the
/// symbol variant instead of @. For example, foo(plt) instead of foo@plt.
bool UseParensForSymbolVariant; // Defaults to false;
//===--- Prologue State ----------------------------------------------===//
std::vector<MCCFIInstruction> InitialFrameState;
public:
explicit MCAsmInfo();
virtual ~MCAsmInfo();
// FIXME: move these methods to DwarfPrinter when the JIT stops using them.
static unsigned getSLEB128Size(int64_t Value);
static unsigned getULEB128Size(uint64_t Value);
/// getPointerSize - Get the pointer size in bytes.
unsigned getPointerSize() const {
return PointerSize;
}
/// getCalleeSaveStackSlotSize - Get the callee-saved register stack slot
/// size in bytes.
unsigned getCalleeSaveStackSlotSize() const {
return CalleeSaveStackSlotSize;
}
/// isLittleEndian - True if the target is little endian.
bool isLittleEndian() const {
return IsLittleEndian;
}
/// isStackGrowthDirectionUp - 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; }
/// getNonexecutableStackSection - 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 0;
}
virtual const MCExpr *
getExprForPersonalitySymbol(const MCSymbol *Sym,
unsigned Encoding,
MCStreamer &Streamer) const;
const MCExpr *
getExprForFDESymbol(const MCSymbol *Sym,
unsigned Encoding,
MCStreamer &Streamer) const;
bool usesSunStyleELFSectionSwitchSyntax() const {
return SunStyleELFSectionSwitchSyntax;
}
bool usesELFSectionDirectiveForBSS() const {
return UsesELFSectionDirectiveForBSS;
}
bool hasMicrosoftFastStdCallMangling() const {
return HasMicrosoftFastStdCallMangling;
}
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;
}
unsigned getCommentColumn() const {
return CommentColumn;
}
const char *getCommentString() const {
return CommentString;
}
const char *getLabelSuffix() const {
return LabelSuffix;
}
This patch is needed to make c++ exceptions work for mips16. Mips16 is really a processor decoding mode (ala thumb 1) and in the same program, mips16 and mips32 functions can exist and can call each other. If a jal type instruction encounters an address with the lower bit set, then the processor switches to mips16 mode (if it is not already in it). If the lower bit is not set, then it switches to mips32 mode. The linker knows which functions are mips16 and which are mips32. When relocation is performed on code labels, this lower order bit is set if the code label is a mips16 code label. In general this works just fine, however when creating exception handling tables and dwarf, there are cases where you don't want this lower order bit added in. This has been traditionally distinguished in gas assembly source by using a different syntax for the label. lab1: ; this will cause the lower order bit to be added lab2=. ; this will not cause the lower order bit to be added In some cases, it does not matter because in dwarf and debug tables the difference of two labels is used and in that case the lower order bits subtract each other out. To fix this, I have added to mcstreamer the notion of a debuglabel. The default is for label and debug label to be the same. So calling EmitLabel and EmitDebugLabel produce the same result. For various reasons, there is only one set of labels that needs to be modified for the mips exceptions to work. These are the "$eh_func_beginXXX" labels. Mips overrides the debug label suffix from ":" to "=." . This initial patch fixes exceptions. More changes most likely will be needed to DwarfCFException to make all of this work for actual debugging. These changes will be to emit debug labels in some places where a simple label is emitted now. Some historical discussion on this from gcc can be found at: http://gcc.gnu.org/ml/gcc-patches/2008-08/msg00623.html http://gcc.gnu.org/ml/gcc-patches/2008-11/msg01273.html git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170279 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-16 04:00:45 +00:00
const char *getDebugLabelSuffix() const {
return DebugLabelSuffix;
}
char getGlobalPrefix() const {
return GlobalPrefix;
}
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;
}
const char *getAlignDirective() const {
return AlignDirective;
}
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::ExceptionsType getExceptionHandlingType() const {
return ExceptionsType;
}
bool isExceptionHandlingDwarf() const {
return
(ExceptionsType == ExceptionHandling::DwarfCFI ||
ExceptionsType == ExceptionHandling::ARM ||
ExceptionsType == ExceptionHandling::Win64);
}
bool doesDwarfUseRelocationsAcrossSections() const {
return DwarfUsesRelocationsAcrossSections;
}
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;
}
};
}
#endif