1 //===-- llvm/MC/MCAsmInfo.h - Asm info --------------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains a class to be used as the basis for target specific
11 // asm writers. This class primarily takes care of global printing constants,
12 // which are used in very similar ways across all targets.
14 //===----------------------------------------------------------------------===//
16 #ifndef LLVM_TARGET_ASM_INFO_H
17 #define LLVM_TARGET_ASM_INFO_H
19 #include "llvm/MC/MCDirectives.h"
26 /// MCAsmInfo - This class is intended to be used as a base class for asm
27 /// properties and features specific to the target.
28 namespace ExceptionHandling {
29 enum ExceptionsType { None, DwarfTable, DwarfCFI, SjLj, ARM };
34 //===------------------------------------------------------------------===//
35 // Properties to be set by the target writer, used to configure asm printer.
38 /// HasSubsectionsViaSymbols - True if this target has the MachO
39 /// .subsections_via_symbols directive.
40 bool HasSubsectionsViaSymbols; // Default is false.
42 /// HasMachoZeroFillDirective - True if this is a MachO target that supports
43 /// the macho-specific .zerofill directive for emitting BSS Symbols.
44 bool HasMachoZeroFillDirective; // Default is false.
46 /// HasMachoTBSSDirective - True if this is a MachO target that supports
47 /// the macho-specific .tbss directive for emitting thread local BSS Symbols
48 bool HasMachoTBSSDirective; // Default is false.
50 /// HasStaticCtorDtorReferenceInStaticMode - True if the compiler should
51 /// emit a ".reference .constructors_used" or ".reference .destructors_used"
52 /// directive after the a static ctor/dtor list. This directive is only
53 /// emitted in Static relocation model.
54 bool HasStaticCtorDtorReferenceInStaticMode; // Default is false.
56 /// LinkerRequiresNonEmptyDwarfLines - True if the linker has a bug and
57 /// requires that the debug_line section be of a minimum size. In practice
58 /// such a linker requires a non empty line sequence if a file is present.
59 bool LinkerRequiresNonEmptyDwarfLines; // Default to false.
61 /// MaxInstLength - This is the maximum possible length of an instruction,
62 /// which is needed to compute the size of an inline asm.
63 unsigned MaxInstLength; // Defaults to 4.
65 /// PCSymbol - The symbol used to represent the current PC. Used in PC
66 /// relative expressions.
67 const char *PCSymbol; // Defaults to "$".
69 /// SeparatorString - This string, if specified, is used to separate
70 /// instructions from each other when on the same line.
71 const char *SeparatorString; // Defaults to ';'
73 /// CommentColumn - This indicates the comment num (zero-based) at
74 /// which asm comments should be printed.
75 unsigned CommentColumn; // Defaults to 40
77 /// CommentString - This indicates the comment character used by the
79 const char *CommentString; // Defaults to "#"
81 /// LabelSuffix - This is appended to emitted labels.
82 const char *LabelSuffix; // Defaults to ":"
84 /// GlobalPrefix - If this is set to a non-empty string, it is prepended
85 /// onto all global symbols. This is often used for "_" or ".".
86 const char *GlobalPrefix; // Defaults to ""
88 /// PrivateGlobalPrefix - This prefix is used for globals like constant
89 /// pool entries that are completely private to the .s file and should not
90 /// have names in the .o file. This is often "." or "L".
91 const char *PrivateGlobalPrefix; // Defaults to "."
93 /// LinkerPrivateGlobalPrefix - This prefix is used for symbols that should
94 /// be passed through the assembler but be removed by the linker. This
95 /// is "l" on Darwin, currently used for some ObjC metadata.
96 const char *LinkerPrivateGlobalPrefix; // Defaults to ""
98 /// InlineAsmStart/End - If these are nonempty, they contain a directive to
99 /// emit before and after an inline assembly statement.
100 const char *InlineAsmStart; // Defaults to "#APP\n"
101 const char *InlineAsmEnd; // Defaults to "#NO_APP\n"
103 /// AssemblerDialect - Which dialect of an assembler variant to use.
104 unsigned AssemblerDialect; // Defaults to 0
106 /// AllowQuotesInName - This is true if the assembler allows for complex
107 /// symbol names to be surrounded in quotes. This defaults to false.
108 bool AllowQuotesInName;
110 /// AllowNameToStartWithDigit - This is true if the assembler allows symbol
111 /// names to start with a digit (e.g., "0x0021"). This defaults to false.
112 bool AllowNameToStartWithDigit;
114 /// AllowPeriodsInName - This is true if the assembler allows periods in
115 /// symbol names. This defaults to true.
116 bool AllowPeriodsInName;
118 //===--- Data Emission Directives -------------------------------------===//
120 /// ZeroDirective - this should be set to the directive used to get some
121 /// number of zero bytes emitted to the current section. Common cases are
122 /// "\t.zero\t" and "\t.space\t". If this is set to null, the
123 /// Data*bitsDirective's will be used to emit zero bytes.
124 const char *ZeroDirective; // Defaults to "\t.zero\t"
126 /// AsciiDirective - This directive allows emission of an ascii string with
127 /// the standard C escape characters embedded into it.
128 const char *AsciiDirective; // Defaults to "\t.ascii\t"
130 /// AscizDirective - If not null, this allows for special handling of
131 /// zero terminated strings on this target. This is commonly supported as
132 /// ".asciz". If a target doesn't support this, it can be set to null.
133 const char *AscizDirective; // Defaults to "\t.asciz\t"
135 /// DataDirectives - These directives are used to output some unit of
136 /// integer data to the current section. If a data directive is set to
137 /// null, smaller data directives will be used to emit the large sizes.
138 const char *Data8bitsDirective; // Defaults to "\t.byte\t"
139 const char *Data16bitsDirective; // Defaults to "\t.short\t"
140 const char *Data32bitsDirective; // Defaults to "\t.long\t"
141 const char *Data64bitsDirective; // Defaults to "\t.quad\t"
143 /// GPRel32Directive - if non-null, a directive that is used to emit a word
144 /// which should be relocated as a 32-bit GP-relative offset, e.g. .gpword
145 /// on Mips or .gprel32 on Alpha.
146 const char *GPRel32Directive; // Defaults to NULL.
148 /// getDataASDirective - Return the directive that should be used to emit
149 /// data of the specified size to the specified numeric address space.
150 virtual const char *getDataASDirective(unsigned Size, unsigned AS) const {
151 assert(AS != 0 && "Don't know the directives for default addr space");
155 /// SunStyleELFSectionSwitchSyntax - This is true if this target uses "Sun
156 /// Style" syntax for section switching ("#alloc,#write" etc) instead of the
157 /// normal ELF syntax (,"a,w") in .section directives.
158 bool SunStyleELFSectionSwitchSyntax; // Defaults to false.
160 /// UsesELFSectionDirectiveForBSS - This is true if this target uses ELF
161 /// '.section' directive before the '.bss' one. It's used for PPC/Linux
162 /// which doesn't support the '.bss' directive only.
163 bool UsesELFSectionDirectiveForBSS; // Defaults to false.
165 /// HasMicrosoftFastStdCallMangling - True if this target uses microsoft
166 /// style mangling for functions with X86_StdCall/X86_FastCall calling
168 bool HasMicrosoftFastStdCallMangling; // Defaults to false.
170 //===--- Alignment Information ----------------------------------------===//
172 /// AlignDirective - The directive used to emit round up to an alignment
175 const char *AlignDirective; // Defaults to "\t.align\t"
177 /// AlignmentIsInBytes - If this is true (the default) then the asmprinter
178 /// emits ".align N" directives, where N is the number of bytes to align to.
179 /// Otherwise, it emits ".align log2(N)", e.g. 3 to align to an 8 byte
181 bool AlignmentIsInBytes; // Defaults to true
183 /// TextAlignFillValue - If non-zero, this is used to fill the executable
184 /// space created as the result of a alignment directive.
185 unsigned TextAlignFillValue; // Defaults to 0
187 //===--- Global Variable Emission Directives --------------------------===//
189 /// GlobalDirective - This is the directive used to declare a global entity.
191 const char *GlobalDirective; // Defaults to NULL.
193 /// ExternDirective - This is the directive used to declare external
196 const char *ExternDirective; // Defaults to NULL.
198 /// HasSetDirective - True if the assembler supports the .set directive.
199 bool HasSetDirective; // Defaults to true.
201 /// HasAggressiveSymbolFolding - False if the assembler requires that we use
206 bool HasAggressiveSymbolFolding; // Defaults to true.
208 /// HasLCOMMDirective - This is true if the target supports the .lcomm
210 bool HasLCOMMDirective; // Defaults to false.
212 /// COMMDirectiveAlignmentIsInBytes - True is COMMDirective's optional
213 /// alignment is to be specified in bytes instead of log2(n).
214 bool COMMDirectiveAlignmentIsInBytes; // Defaults to true;
216 /// HasDotTypeDotSizeDirective - True if the target has .type and .size
217 /// directives, this is true for most ELF targets.
218 bool HasDotTypeDotSizeDirective; // Defaults to true.
220 /// HasSingleParameterDotFile - True if the target has a single parameter
221 /// .file directive, this is true for ELF targets.
222 bool HasSingleParameterDotFile; // Defaults to true.
224 /// HasNoDeadStrip - True if this target supports the MachO .no_dead_strip
226 bool HasNoDeadStrip; // Defaults to false.
228 /// HasSymbolResolver - True if this target supports the MachO
229 /// .symbol_resolver directive.
230 bool HasSymbolResolver; // Defaults to false.
232 /// WeakRefDirective - This directive, if non-null, is used to declare a
233 /// global as being a weak undefined symbol.
234 const char *WeakRefDirective; // Defaults to NULL.
236 /// WeakDefDirective - This directive, if non-null, is used to declare a
237 /// global as being a weak defined symbol.
238 const char *WeakDefDirective; // Defaults to NULL.
240 /// LinkOnceDirective - This directive, if non-null is used to declare a
241 /// global as being a weak defined symbol. This is used on cygwin/mingw.
242 const char *LinkOnceDirective; // Defaults to NULL.
244 /// HiddenVisibilityAttr - This attribute, if not MCSA_Invalid, is used to
245 /// declare a symbol as having hidden visibility.
246 MCSymbolAttr HiddenVisibilityAttr; // Defaults to MCSA_Hidden.
248 /// HiddenDeclarationVisibilityAttr - This attribute, if not MCSA_Invalid,
249 /// is used to declare an undefined symbol as having hidden visibility.
250 MCSymbolAttr HiddenDeclarationVisibilityAttr; // Defaults to MCSA_Hidden.
253 /// ProtectedVisibilityAttr - This attribute, if not MCSA_Invalid, is used
254 /// to declare a symbol as having protected visibility.
255 MCSymbolAttr ProtectedVisibilityAttr; // Defaults to MCSA_Protected
257 //===--- Dwarf Emission Directives -----------------------------------===//
259 /// HasLEB128 - True if target asm supports leb128 directives.
260 bool HasLEB128; // Defaults to false.
262 /// SupportsDebugInformation - True if target supports emission of debugging
264 bool SupportsDebugInformation; // Defaults to false.
266 /// SupportsExceptionHandling - True if target supports exception handling.
267 ExceptionHandling::ExceptionsType ExceptionsType; // Defaults to None
269 /// RequiresFrameSection - true if the Dwarf2 output needs a frame section
270 bool DwarfRequiresFrameSection; // Defaults to true.
272 /// DwarfUsesInlineInfoSection - True if DwarfDebugInlineSection is used to
273 /// encode inline subroutine information.
274 bool DwarfUsesInlineInfoSection; // Defaults to false.
276 /// DwarfSectionOffsetDirective - Special section offset directive.
277 const char* DwarfSectionOffsetDirective; // Defaults to NULL
279 /// DwarfUsesAbsoluteLabelForStmtList - True if DW_AT_stmt_list needs
280 /// absolute label instead of offset.
281 bool DwarfUsesAbsoluteLabelForStmtList; // Defaults to true;
283 // DwarfUsesLabelOffsetDifference - True if Dwarf2 output can
284 // use EmitLabelOffsetDifference.
285 bool DwarfUsesLabelOffsetForRanges;
287 //===--- CBE Asm Translation Table -----------------------------------===//
289 const char *const *AsmTransCBE; // Defaults to empty
292 explicit MCAsmInfo();
293 virtual ~MCAsmInfo();
295 // FIXME: move these methods to DwarfPrinter when the JIT stops using them.
296 static unsigned getSLEB128Size(int Value);
297 static unsigned getULEB128Size(unsigned Value);
299 bool hasSubsectionsViaSymbols() const { return HasSubsectionsViaSymbols; }
301 // Data directive accessors.
303 const char *getData8bitsDirective(unsigned AS = 0) const {
304 return AS == 0 ? Data8bitsDirective : getDataASDirective(8, AS);
306 const char *getData16bitsDirective(unsigned AS = 0) const {
307 return AS == 0 ? Data16bitsDirective : getDataASDirective(16, AS);
309 const char *getData32bitsDirective(unsigned AS = 0) const {
310 return AS == 0 ? Data32bitsDirective : getDataASDirective(32, AS);
312 const char *getData64bitsDirective(unsigned AS = 0) const {
313 return AS == 0 ? Data64bitsDirective : getDataASDirective(64, AS);
315 const char *getGPRel32Directive() const { return GPRel32Directive; }
317 /// getNonexecutableStackSection - Targets can implement this method to
318 /// specify a section to switch to if the translation unit doesn't have any
319 /// trampolines that require an executable stack.
320 virtual const MCSection *getNonexecutableStackSection(MCContext &Ctx) const{
324 bool usesSunStyleELFSectionSwitchSyntax() const {
325 return SunStyleELFSectionSwitchSyntax;
328 bool usesELFSectionDirectiveForBSS() const {
329 return UsesELFSectionDirectiveForBSS;
332 bool hasMicrosoftFastStdCallMangling() const {
333 return HasMicrosoftFastStdCallMangling;
338 bool hasMachoZeroFillDirective() const { return HasMachoZeroFillDirective; }
339 bool hasMachoTBSSDirective() const { return HasMachoTBSSDirective; }
340 bool hasStaticCtorDtorReferenceInStaticMode() const {
341 return HasStaticCtorDtorReferenceInStaticMode;
343 bool getLinkerRequiresNonEmptyDwarfLines() const {
344 return LinkerRequiresNonEmptyDwarfLines;
346 unsigned getMaxInstLength() const {
347 return MaxInstLength;
349 const char *getPCSymbol() const {
352 const char *getSeparatorString() const {
353 return SeparatorString;
355 unsigned getCommentColumn() const {
356 return CommentColumn;
358 const char *getCommentString() const {
359 return CommentString;
361 const char *getLabelSuffix() const {
364 const char *getGlobalPrefix() const {
367 const char *getPrivateGlobalPrefix() const {
368 return PrivateGlobalPrefix;
370 const char *getLinkerPrivateGlobalPrefix() const {
371 return LinkerPrivateGlobalPrefix;
373 const char *getInlineAsmStart() const {
374 return InlineAsmStart;
376 const char *getInlineAsmEnd() const {
379 unsigned getAssemblerDialect() const {
380 return AssemblerDialect;
382 bool doesAllowQuotesInName() const {
383 return AllowQuotesInName;
385 bool doesAllowNameToStartWithDigit() const {
386 return AllowNameToStartWithDigit;
388 bool doesAllowPeriodsInName() const {
389 return AllowPeriodsInName;
391 const char *getZeroDirective() const {
392 return ZeroDirective;
394 const char *getAsciiDirective() const {
395 return AsciiDirective;
397 const char *getAscizDirective() const {
398 return AscizDirective;
400 const char *getAlignDirective() const {
401 return AlignDirective;
403 bool getAlignmentIsInBytes() const {
404 return AlignmentIsInBytes;
406 unsigned getTextAlignFillValue() const {
407 return TextAlignFillValue;
409 const char *getGlobalDirective() const {
410 return GlobalDirective;
412 const char *getExternDirective() const {
413 return ExternDirective;
415 bool hasSetDirective() const { return HasSetDirective; }
416 bool hasAggressiveSymbolFolding() const {
417 return HasAggressiveSymbolFolding;
419 bool hasLCOMMDirective() const { return HasLCOMMDirective; }
420 bool hasDotTypeDotSizeDirective() const {return HasDotTypeDotSizeDirective;}
421 bool getCOMMDirectiveAlignmentIsInBytes() const {
422 return COMMDirectiveAlignmentIsInBytes;
424 bool hasSingleParameterDotFile() const { return HasSingleParameterDotFile; }
425 bool hasNoDeadStrip() const { return HasNoDeadStrip; }
426 bool hasSymbolResolver() const { return HasSymbolResolver; }
427 const char *getWeakRefDirective() const { return WeakRefDirective; }
428 const char *getWeakDefDirective() const { return WeakDefDirective; }
429 const char *getLinkOnceDirective() const { return LinkOnceDirective; }
431 MCSymbolAttr getHiddenVisibilityAttr() const { return HiddenVisibilityAttr;}
432 MCSymbolAttr getHiddenDeclarationVisibilityAttr() const {
433 return HiddenDeclarationVisibilityAttr;
435 MCSymbolAttr getProtectedVisibilityAttr() const {
436 return ProtectedVisibilityAttr;
438 bool hasLEB128() const {
441 bool doesSupportDebugInformation() const {
442 return SupportsDebugInformation;
444 bool doesSupportExceptionHandling() const {
445 return ExceptionsType != ExceptionHandling::None;
447 ExceptionHandling::ExceptionsType getExceptionHandlingType() const {
448 return ExceptionsType;
450 bool isExceptionHandlingDwarf() const {
452 (ExceptionsType == ExceptionHandling::DwarfTable ||
453 ExceptionsType == ExceptionHandling::DwarfCFI ||
454 ExceptionsType == ExceptionHandling::ARM);
457 bool doesDwarfRequireFrameSection() const {
458 return DwarfRequiresFrameSection;
460 bool doesDwarfUsesInlineInfoSection() const {
461 return DwarfUsesInlineInfoSection;
463 const char *getDwarfSectionOffsetDirective() const {
464 return DwarfSectionOffsetDirective;
466 bool doesDwarfUsesAbsoluteLabelForStmtList() const {
467 return DwarfUsesAbsoluteLabelForStmtList;
469 bool doesDwarfUsesLabelOffsetForRanges() const {
470 return DwarfUsesLabelOffsetForRanges;
472 const char *const *getAsmCBE() const {