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 { enum ExceptionsType { None, Dwarf, SjLj }; }
32 //===------------------------------------------------------------------===//
33 // Properties to be set by the target writer, used to configure asm printer.
36 /// HasSubsectionsViaSymbols - True if this target has the MachO
37 /// .subsections_via_symbols directive.
38 bool HasSubsectionsViaSymbols; // Default is false.
40 /// HasMachoZeroFillDirective - True if this is a MachO target that supports
41 /// the macho-specific .zerofill directive for emitting BSS Symbols.
42 bool HasMachoZeroFillDirective; // Default is false.
44 /// HasMachoTBSSDirective - True if this is a MachO target that supports
45 /// the macho-specific .tbss directive for emitting thread local BSS Symbols
46 bool HasMachoTBSSDirective; // Default is false.
48 /// HasStaticCtorDtorReferenceInStaticMode - True if the compiler should
49 /// emit a ".reference .constructors_used" or ".reference .destructors_used"
50 /// directive after the a static ctor/dtor list. This directive is only
51 /// emitted in Static relocation model.
52 bool HasStaticCtorDtorReferenceInStaticMode; // Default is false.
54 /// LinkerRequiresNonEmptyDwarfLines - True if the linker has a bug and
55 /// requires that the debug_line section be of a minimum size. In practice
56 /// such a linker requires a non empty line sequence if a file is present.
57 bool LinkerRequiresNonEmptyDwarfLines; // Default to false.
59 /// MaxInstLength - This is the maximum possible length of an instruction,
60 /// which is needed to compute the size of an inline asm.
61 unsigned MaxInstLength; // Defaults to 4.
63 /// PCSymbol - The symbol used to represent the current PC. Used in PC
64 /// relative expressions.
65 const char *PCSymbol; // Defaults to "$".
67 /// SeparatorChar - This character, if specified, is used to separate
68 /// instructions from each other when on the same line. This is used to
69 /// measure inline asm instructions.
70 char SeparatorChar; // Defaults to ';'
72 /// CommentColumn - This indicates the comment num (zero-based) at
73 /// which asm comments should be printed.
74 unsigned CommentColumn; // Defaults to 40
76 /// CommentString - This indicates the comment character used by the
78 const char *CommentString; // Defaults to "#"
80 /// LabelSuffix - This is appended to emitted labels.
81 const char *LabelSuffix; // Defaults to ":"
83 /// GlobalPrefix - If this is set to a non-empty string, it is prepended
84 /// onto all global symbols. This is often used for "_" or ".".
85 const char *GlobalPrefix; // Defaults to ""
87 /// PrivateGlobalPrefix - This prefix is used for globals like constant
88 /// pool entries that are completely private to the .s file and should not
89 /// have names in the .o file. This is often "." or "L".
90 const char *PrivateGlobalPrefix; // Defaults to "."
92 /// LinkerPrivateGlobalPrefix - This prefix is used for symbols that should
93 /// be passed through the assembler but be removed by the linker. This
94 /// is "l" on Darwin, currently used for some ObjC metadata.
95 const char *LinkerPrivateGlobalPrefix; // Defaults to ""
97 /// InlineAsmStart/End - If these are nonempty, they contain a directive to
98 /// emit before and after an inline assembly statement.
99 const char *InlineAsmStart; // Defaults to "#APP\n"
100 const char *InlineAsmEnd; // Defaults to "#NO_APP\n"
102 /// AssemblerDialect - Which dialect of an assembler variant to use.
103 unsigned AssemblerDialect; // Defaults to 0
105 /// AllowQuotesInName - This is true if the assembler allows for complex
106 /// symbol names to be surrounded in quotes. This defaults to false.
107 bool AllowQuotesInName;
109 /// AllowNameToStartWithDigit - This is true if the assembler allows symbol
110 /// names to start with a digit (e.g., "0x0021"). This defaults to false.
111 bool AllowNameToStartWithDigit;
113 /// AllowPeriodsInName - This is true if the assembler allows periods in
114 /// symbol names. This defaults to true.
115 bool AllowPeriodsInName;
117 //===--- Data Emission Directives -------------------------------------===//
119 /// ZeroDirective - this should be set to the directive used to get some
120 /// number of zero bytes emitted to the current section. Common cases are
121 /// "\t.zero\t" and "\t.space\t". If this is set to null, the
122 /// Data*bitsDirective's will be used to emit zero bytes.
123 const char *ZeroDirective; // Defaults to "\t.zero\t"
125 /// AsciiDirective - This directive allows emission of an ascii string with
126 /// the standard C escape characters embedded into it.
127 const char *AsciiDirective; // Defaults to "\t.ascii\t"
129 /// AscizDirective - If not null, this allows for special handling of
130 /// zero terminated strings on this target. This is commonly supported as
131 /// ".asciz". If a target doesn't support this, it can be set to null.
132 const char *AscizDirective; // Defaults to "\t.asciz\t"
134 /// DataDirectives - These directives are used to output some unit of
135 /// integer data to the current section. If a data directive is set to
136 /// null, smaller data directives will be used to emit the large sizes.
137 const char *Data8bitsDirective; // Defaults to "\t.byte\t"
138 const char *Data16bitsDirective; // Defaults to "\t.short\t"
139 const char *Data32bitsDirective; // Defaults to "\t.long\t"
140 const char *Data64bitsDirective; // Defaults to "\t.quad\t"
142 /// GPRel32Directive - if non-null, a directive that is used to emit a word
143 /// which should be relocated as a 32-bit GP-relative offset, e.g. .gpword
144 /// on Mips or .gprel32 on Alpha.
145 const char *GPRel32Directive; // Defaults to NULL.
147 /// getDataASDirective - Return the directive that should be used to emit
148 /// data of the specified size to the specified numeric address space.
149 virtual const char *getDataASDirective(unsigned Size, unsigned AS) const {
150 assert(AS != 0 && "Don't know the directives for default addr space");
154 /// SunStyleELFSectionSwitchSyntax - This is true if this target uses "Sun
155 /// Style" syntax for section switching ("#alloc,#write" etc) instead of the
156 /// normal ELF syntax (,"a,w") in .section directives.
157 bool SunStyleELFSectionSwitchSyntax; // Defaults to false.
159 /// UsesELFSectionDirectiveForBSS - This is true if this target uses ELF
160 /// '.section' directive before the '.bss' one. It's used for PPC/Linux
161 /// which doesn't support the '.bss' directive only.
162 bool UsesELFSectionDirectiveForBSS; // Defaults to false.
164 /// HasMicrosoftFastStdCallMangling - True if this target uses microsoft
165 /// style mangling for functions with X86_StdCall/X86_FastCall calling
167 bool HasMicrosoftFastStdCallMangling; // Defaults to false.
169 //===--- Alignment Information ----------------------------------------===//
171 /// AlignDirective - The directive used to emit round up to an alignment
174 const char *AlignDirective; // Defaults to "\t.align\t"
176 /// AlignmentIsInBytes - If this is true (the default) then the asmprinter
177 /// emits ".align N" directives, where N is the number of bytes to align to.
178 /// Otherwise, it emits ".align log2(N)", e.g. 3 to align to an 8 byte
180 bool AlignmentIsInBytes; // Defaults to true
182 /// TextAlignFillValue - If non-zero, this is used to fill the executable
183 /// space created as the result of a alignment directive.
184 unsigned TextAlignFillValue; // Defaults to 0
186 //===--- Global Variable Emission Directives --------------------------===//
188 /// GlobalDirective - This is the directive used to declare a global entity.
190 const char *GlobalDirective; // Defaults to NULL.
192 /// ExternDirective - This is the directive used to declare external
195 const char *ExternDirective; // Defaults to NULL.
197 /// HasSetDirective - True if the assembler supports the .set directive.
198 bool HasSetDirective; // Defaults to true.
200 /// NeedsSetToChangeDiffSize - True if the assembler requires that we do
205 bool NeedsSetToChangeDiffSize; // Defaults to false.
207 /// HasLCOMMDirective - This is true if the target supports the .lcomm
209 bool HasLCOMMDirective; // Defaults to false.
211 /// COMMDirectiveAlignmentIsInBytes - True is COMMDirective's optional
212 /// alignment is to be specified in bytes instead of log2(n).
213 bool COMMDirectiveAlignmentIsInBytes; // Defaults to true;
215 /// HasDotTypeDotSizeDirective - True if the target has .type and .size
216 /// directives, this is true for most ELF targets.
217 bool HasDotTypeDotSizeDirective; // Defaults to true.
219 /// HasSingleParameterDotFile - True if the target has a single parameter
220 /// .file directive, this is true for ELF targets.
221 bool HasSingleParameterDotFile; // Defaults to true.
223 /// HasNoDeadStrip - True if this target supports the MachO .no_dead_strip
225 bool HasNoDeadStrip; // Defaults to false.
227 /// HasSymbolResolver - True if this target supports the MachO
228 /// .symbol_resolver directive.
229 bool HasSymbolResolver; // Defaults to false.
231 /// WeakRefDirective - This directive, if non-null, is used to declare a
232 /// global as being a weak undefined symbol.
233 const char *WeakRefDirective; // Defaults to NULL.
235 /// WeakDefDirective - This directive, if non-null, is used to declare a
236 /// global as being a weak defined symbol.
237 const char *WeakDefDirective; // Defaults to NULL.
239 /// LinkOnceDirective - This directive, if non-null is used to declare a
240 /// global as being a weak defined symbol. This is used on cygwin/mingw.
241 const char *LinkOnceDirective; // Defaults to NULL.
243 /// HiddenVisibilityAttr - This attribute, if not MCSA_Invalid, is used to
244 /// declare a symbol as having hidden visibility.
245 MCSymbolAttr HiddenVisibilityAttr; // Defaults to MCSA_Hidden.
247 /// ProtectedVisibilityAttr - This attribute, if not MCSA_Invalid, is used
248 /// to declare a symbol as having protected visibility.
249 MCSymbolAttr ProtectedVisibilityAttr; // Defaults to MCSA_Protected
251 //===--- Dwarf Emission Directives -----------------------------------===//
253 /// HasLEB128 - True if target asm supports leb128 directives.
254 bool HasLEB128; // Defaults to false.
256 /// SupportsDebugInformation - True if target supports emission of debugging
258 bool SupportsDebugInformation; // Defaults to false.
260 /// SupportsExceptionHandling - True if target supports exception handling.
261 ExceptionHandling::ExceptionsType ExceptionsType; // Defaults to None
263 /// RequiresFrameSection - true if the Dwarf2 output needs a frame section
264 bool DwarfRequiresFrameSection; // Defaults to true.
266 /// DwarfUsesInlineInfoSection - True if DwarfDebugInlineSection is used to
267 /// encode inline subroutine information.
268 bool DwarfUsesInlineInfoSection; // Defaults to false.
270 /// DwarfSectionOffsetDirective - Special section offset directive.
271 const char* DwarfSectionOffsetDirective; // Defaults to NULL
273 /// DwarfUsesAbsoluteLabelForStmtList - True if DW_AT_stmt_list needs
274 /// absolute label instead of offset.
275 bool DwarfUsesAbsoluteLabelForStmtList; // Defaults to true;
277 // DwarfUsesLabelOffsetDifference - True if Dwarf2 output can
278 // use EmitLabelOffsetDifference.
279 bool DwarfUsesLabelOffsetForRanges;
281 //===--- CBE Asm Translation Table -----------------------------------===//
283 const char *const *AsmTransCBE; // Defaults to empty
286 explicit MCAsmInfo();
287 virtual ~MCAsmInfo();
289 // FIXME: move these methods to DwarfPrinter when the JIT stops using them.
290 static unsigned getSLEB128Size(int Value);
291 static unsigned getULEB128Size(unsigned Value);
293 bool hasSubsectionsViaSymbols() const { return HasSubsectionsViaSymbols; }
295 // Data directive accessors.
297 const char *getData8bitsDirective(unsigned AS = 0) const {
298 return AS == 0 ? Data8bitsDirective : getDataASDirective(8, AS);
300 const char *getData16bitsDirective(unsigned AS = 0) const {
301 return AS == 0 ? Data16bitsDirective : getDataASDirective(16, AS);
303 const char *getData32bitsDirective(unsigned AS = 0) const {
304 return AS == 0 ? Data32bitsDirective : getDataASDirective(32, AS);
306 const char *getData64bitsDirective(unsigned AS = 0) const {
307 return AS == 0 ? Data64bitsDirective : getDataASDirective(64, AS);
309 const char *getGPRel32Directive() const { return GPRel32Directive; }
311 /// getNonexecutableStackSection - Targets can implement this method to
312 /// specify a section to switch to if the translation unit doesn't have any
313 /// trampolines that require an executable stack.
314 virtual const MCSection *getNonexecutableStackSection(MCContext &Ctx) const{
318 bool usesSunStyleELFSectionSwitchSyntax() const {
319 return SunStyleELFSectionSwitchSyntax;
322 bool usesELFSectionDirectiveForBSS() const {
323 return UsesELFSectionDirectiveForBSS;
326 bool hasMicrosoftFastStdCallMangling() const {
327 return HasMicrosoftFastStdCallMangling;
332 bool hasMachoZeroFillDirective() const { return HasMachoZeroFillDirective; }
333 bool hasMachoTBSSDirective() const { return HasMachoTBSSDirective; }
334 bool hasStaticCtorDtorReferenceInStaticMode() const {
335 return HasStaticCtorDtorReferenceInStaticMode;
337 bool getLinkerRequiresNonEmptyDwarfLines() const {
338 return LinkerRequiresNonEmptyDwarfLines;
340 unsigned getMaxInstLength() const {
341 return MaxInstLength;
343 const char *getPCSymbol() const {
346 char getSeparatorChar() const {
347 return SeparatorChar;
349 unsigned getCommentColumn() const {
350 return CommentColumn;
352 const char *getCommentString() const {
353 return CommentString;
355 const char *getLabelSuffix() const {
358 const char *getGlobalPrefix() const {
361 const char *getPrivateGlobalPrefix() const {
362 return PrivateGlobalPrefix;
364 const char *getLinkerPrivateGlobalPrefix() const {
365 return LinkerPrivateGlobalPrefix;
367 const char *getInlineAsmStart() const {
368 return InlineAsmStart;
370 const char *getInlineAsmEnd() const {
373 unsigned getAssemblerDialect() const {
374 return AssemblerDialect;
376 bool doesAllowQuotesInName() const {
377 return AllowQuotesInName;
379 bool doesAllowNameToStartWithDigit() const {
380 return AllowNameToStartWithDigit;
382 bool doesAllowPeriodsInName() const {
383 return AllowPeriodsInName;
385 const char *getZeroDirective() const {
386 return ZeroDirective;
388 const char *getAsciiDirective() const {
389 return AsciiDirective;
391 const char *getAscizDirective() const {
392 return AscizDirective;
394 const char *getAlignDirective() const {
395 return AlignDirective;
397 bool getAlignmentIsInBytes() const {
398 return AlignmentIsInBytes;
400 unsigned getTextAlignFillValue() const {
401 return TextAlignFillValue;
403 const char *getGlobalDirective() const {
404 return GlobalDirective;
406 const char *getExternDirective() const {
407 return ExternDirective;
409 bool hasSetDirective() const { return HasSetDirective; }
410 bool needsSetToChangeDiffSize() const { return NeedsSetToChangeDiffSize; }
411 bool hasLCOMMDirective() const { return HasLCOMMDirective; }
412 bool hasDotTypeDotSizeDirective() const {return HasDotTypeDotSizeDirective;}
413 bool getCOMMDirectiveAlignmentIsInBytes() const {
414 return COMMDirectiveAlignmentIsInBytes;
416 bool hasSingleParameterDotFile() const { return HasSingleParameterDotFile; }
417 bool hasNoDeadStrip() const { return HasNoDeadStrip; }
418 bool hasSymbolResolver() const { return HasSymbolResolver; }
419 const char *getWeakRefDirective() const { return WeakRefDirective; }
420 const char *getWeakDefDirective() const { return WeakDefDirective; }
421 const char *getLinkOnceDirective() const { return LinkOnceDirective; }
423 MCSymbolAttr getHiddenVisibilityAttr() const { return HiddenVisibilityAttr;}
424 MCSymbolAttr getProtectedVisibilityAttr() const {
425 return ProtectedVisibilityAttr;
427 bool hasLEB128() const {
430 bool doesSupportDebugInformation() const {
431 return SupportsDebugInformation;
433 bool doesSupportExceptionHandling() const {
434 return ExceptionsType != ExceptionHandling::None;
436 ExceptionHandling::ExceptionsType getExceptionHandlingType() const {
437 return ExceptionsType;
439 bool doesDwarfRequireFrameSection() const {
440 return DwarfRequiresFrameSection;
442 bool doesDwarfUsesInlineInfoSection() const {
443 return DwarfUsesInlineInfoSection;
445 const char *getDwarfSectionOffsetDirective() const {
446 return DwarfSectionOffsetDirective;
448 bool doesDwarfUsesAbsoluteLabelForStmtList() const {
449 return DwarfUsesAbsoluteLabelForStmtList;
451 bool doesDwarfUsesLabelOffsetForRanges() const {
452 return DwarfUsesLabelOffsetForRanges;
454 const char *const *getAsmCBE() const {