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 /// MaxInstLength - This is the maximum possible length of an instruction,
55 /// which is needed to compute the size of an inline asm.
56 unsigned MaxInstLength; // Defaults to 4.
58 /// PCSymbol - The symbol used to represent the current PC. Used in PC
59 /// relative expressions.
60 const char *PCSymbol; // Defaults to "$".
62 /// SeparatorChar - This character, if specified, is used to separate
63 /// instructions from each other when on the same line. This is used to
64 /// measure inline asm instructions.
65 char SeparatorChar; // Defaults to ';'
67 /// CommentColumn - This indicates the comment num (zero-based) at
68 /// which asm comments should be printed.
69 unsigned CommentColumn; // Defaults to 40
71 /// CommentString - This indicates the comment character used by the
73 const char *CommentString; // Defaults to "#"
75 /// GlobalPrefix - If this is set to a non-empty string, it is prepended
76 /// onto all global symbols. This is often used for "_" or ".".
77 const char *GlobalPrefix; // Defaults to ""
79 /// PrivateGlobalPrefix - This prefix is used for globals like constant
80 /// pool entries that are completely private to the .s file and should not
81 /// have names in the .o file. This is often "." or "L".
82 const char *PrivateGlobalPrefix; // Defaults to "."
84 /// LinkerPrivateGlobalPrefix - This prefix is used for symbols that should
85 /// be passed through the assembler but be removed by the linker. This
86 /// is "l" on Darwin, currently used for some ObjC metadata.
87 const char *LinkerPrivateGlobalPrefix; // Defaults to ""
89 /// InlineAsmStart/End - If these are nonempty, they contain a directive to
90 /// emit before and after an inline assembly statement.
91 const char *InlineAsmStart; // Defaults to "#APP\n"
92 const char *InlineAsmEnd; // Defaults to "#NO_APP\n"
94 /// AssemblerDialect - Which dialect of an assembler variant to use.
95 unsigned AssemblerDialect; // Defaults to 0
97 /// AllowQuotesInName - This is true if the assembler allows for complex
98 /// symbol names to be surrounded in quotes. This defaults to false.
99 bool AllowQuotesInName;
101 /// AllowNameToStartWithDigit - This is true if the assembler allows symbol
102 /// names to start with a digit (e.g., "0x0021"). This defaults to false.
103 bool AllowNameToStartWithDigit;
105 /// AllowPeriodsInName - This is true if the assembler allows periods in
106 /// symbol names. This defaults to true.
107 bool AllowPeriodsInName;
109 //===--- Data Emission Directives -------------------------------------===//
111 /// ZeroDirective - this should be set to the directive used to get some
112 /// number of zero bytes emitted to the current section. Common cases are
113 /// "\t.zero\t" and "\t.space\t". If this is set to null, the
114 /// Data*bitsDirective's will be used to emit zero bytes.
115 const char *ZeroDirective; // Defaults to "\t.zero\t"
117 /// AsciiDirective - This directive allows emission of an ascii string with
118 /// the standard C escape characters embedded into it.
119 const char *AsciiDirective; // Defaults to "\t.ascii\t"
121 /// AscizDirective - If not null, this allows for special handling of
122 /// zero terminated strings on this target. This is commonly supported as
123 /// ".asciz". If a target doesn't support this, it can be set to null.
124 const char *AscizDirective; // Defaults to "\t.asciz\t"
126 /// DataDirectives - These directives are used to output some unit of
127 /// integer data to the current section. If a data directive is set to
128 /// null, smaller data directives will be used to emit the large sizes.
129 const char *Data8bitsDirective; // Defaults to "\t.byte\t"
130 const char *Data16bitsDirective; // Defaults to "\t.short\t"
131 const char *Data32bitsDirective; // Defaults to "\t.long\t"
132 const char *Data64bitsDirective; // Defaults to "\t.quad\t"
134 /// GPRel32Directive - if non-null, a directive that is used to emit a word
135 /// which should be relocated as a 32-bit GP-relative offset, e.g. .gpword
136 /// on Mips or .gprel32 on Alpha.
137 const char *GPRel32Directive; // Defaults to NULL.
139 /// getDataASDirective - Return the directive that should be used to emit
140 /// data of the specified size to the specified numeric address space.
141 virtual const char *getDataASDirective(unsigned Size, unsigned AS) const {
142 assert(AS != 0 && "Don't know the directives for default addr space");
146 /// SunStyleELFSectionSwitchSyntax - This is true if this target uses "Sun
147 /// Style" syntax for section switching ("#alloc,#write" etc) instead of the
148 /// normal ELF syntax (,"a,w") in .section directives.
149 bool SunStyleELFSectionSwitchSyntax; // Defaults to false.
151 /// UsesELFSectionDirectiveForBSS - This is true if this target uses ELF
152 /// '.section' directive before the '.bss' one. It's used for PPC/Linux
153 /// which doesn't support the '.bss' directive only.
154 bool UsesELFSectionDirectiveForBSS; // Defaults to false.
156 /// HasMicrosoftFastStdCallMangling - True if this target uses microsoft
157 /// style mangling for functions with X86_StdCall/X86_FastCall calling
159 bool HasMicrosoftFastStdCallMangling; // Defaults to false.
161 //===--- Alignment Information ----------------------------------------===//
163 /// AlignDirective - The directive used to emit round up to an alignment
166 const char *AlignDirective; // Defaults to "\t.align\t"
168 /// AlignmentIsInBytes - If this is true (the default) then the asmprinter
169 /// emits ".align N" directives, where N is the number of bytes to align to.
170 /// Otherwise, it emits ".align log2(N)", e.g. 3 to align to an 8 byte
172 bool AlignmentIsInBytes; // Defaults to true
174 /// TextAlignFillValue - If non-zero, this is used to fill the executable
175 /// space created as the result of a alignment directive.
176 unsigned TextAlignFillValue; // Defaults to 0
178 //===--- Global Variable Emission Directives --------------------------===//
180 /// GlobalDirective - This is the directive used to declare a global entity.
182 const char *GlobalDirective; // Defaults to NULL.
184 /// ExternDirective - This is the directive used to declare external
187 const char *ExternDirective; // Defaults to NULL.
189 /// HasSetDirective - True if the assembler supports the .set directive.
190 bool HasSetDirective; // Defaults to true.
192 /// HasLCOMMDirective - This is true if the target supports the .lcomm
194 bool HasLCOMMDirective; // Defaults to false.
196 /// COMMDirectiveAlignmentIsInBytes - True is COMMDirective's optional
197 /// alignment is to be specified in bytes instead of log2(n).
198 bool COMMDirectiveAlignmentIsInBytes; // Defaults to true;
200 /// HasDotTypeDotSizeDirective - True if the target has .type and .size
201 /// directives, this is true for most ELF targets.
202 bool HasDotTypeDotSizeDirective; // Defaults to true.
204 /// HasSingleParameterDotFile - True if the target has a single parameter
205 /// .file directive, this is true for ELF targets.
206 bool HasSingleParameterDotFile; // Defaults to true.
208 /// HasNoDeadStrip - True if this target supports the MachO .no_dead_strip
210 bool HasNoDeadStrip; // Defaults to false.
212 /// WeakRefDirective - This directive, if non-null, is used to declare a
213 /// global as being a weak undefined symbol.
214 const char *WeakRefDirective; // Defaults to NULL.
216 /// WeakDefDirective - This directive, if non-null, is used to declare a
217 /// global as being a weak defined symbol.
218 const char *WeakDefDirective; // Defaults to NULL.
220 /// LinkOnceDirective - This directive, if non-null is used to declare a
221 /// global as being a weak defined symbol. This is used on cygwin/mingw.
222 const char *LinkOnceDirective; // Defaults to NULL.
224 /// HiddenVisibilityAttr - This attribute, if not MCSA_Invalid, is used to
225 /// declare a symbol as having hidden visibility.
226 MCSymbolAttr HiddenVisibilityAttr; // Defaults to MCSA_Hidden.
228 /// ProtectedVisibilityAttr - This attribute, if not MCSA_Invalid, is used
229 /// to declare a symbol as having protected visibility.
230 MCSymbolAttr ProtectedVisibilityAttr; // Defaults to MCSA_Protected
232 //===--- Dwarf Emission Directives -----------------------------------===//
234 /// HasLEB128 - True if target asm supports leb128 directives.
235 bool HasLEB128; // Defaults to false.
237 /// hasDotLocAndDotFile - True if target asm supports .loc and .file
238 /// directives for emitting debugging information.
239 bool HasDotLocAndDotFile; // Defaults to false.
241 /// SupportsDebugInformation - True if target supports emission of debugging
243 bool SupportsDebugInformation; // Defaults to false.
245 /// SupportsExceptionHandling - True if target supports exception handling.
246 ExceptionHandling::ExceptionsType ExceptionsType; // Defaults to None
248 /// RequiresFrameSection - true if the Dwarf2 output needs a frame section
249 bool DwarfRequiresFrameSection; // Defaults to true.
251 /// DwarfUsesInlineInfoSection - True if DwarfDebugInlineSection is used to
252 /// encode inline subroutine information.
253 bool DwarfUsesInlineInfoSection; // Defaults to false.
255 /// DwarfSectionOffsetDirective - Special section offset directive.
256 const char* DwarfSectionOffsetDirective; // Defaults to NULL
258 /// DwarfUsesAbsoluteLabelForStmtList - True if DW_AT_stmt_list needs
259 /// absolute label instead of offset.
260 bool DwarfUsesAbsoluteLabelForStmtList; // Defaults to true;
262 // DwarfUsesLabelOffsetDifference - True if Dwarf2 output can
263 // use EmitLabelOffsetDifference.
264 bool DwarfUsesLabelOffsetForRanges;
266 //===--- CBE Asm Translation Table -----------------------------------===//
268 const char *const *AsmTransCBE; // Defaults to empty
271 explicit MCAsmInfo();
272 virtual ~MCAsmInfo();
274 // FIXME: move these methods to DwarfPrinter when the JIT stops using them.
275 static unsigned getSLEB128Size(int Value);
276 static unsigned getULEB128Size(unsigned Value);
278 bool hasSubsectionsViaSymbols() const { return HasSubsectionsViaSymbols; }
280 // Data directive accessors.
282 const char *getData8bitsDirective(unsigned AS = 0) const {
283 return AS == 0 ? Data8bitsDirective : getDataASDirective(8, AS);
285 const char *getData16bitsDirective(unsigned AS = 0) const {
286 return AS == 0 ? Data16bitsDirective : getDataASDirective(16, AS);
288 const char *getData32bitsDirective(unsigned AS = 0) const {
289 return AS == 0 ? Data32bitsDirective : getDataASDirective(32, AS);
291 const char *getData64bitsDirective(unsigned AS = 0) const {
292 return AS == 0 ? Data64bitsDirective : getDataASDirective(64, AS);
294 const char *getGPRel32Directive() const { return GPRel32Directive; }
296 /// getNonexecutableStackSection - Targets can implement this method to
297 /// specify a section to switch to if the translation unit doesn't have any
298 /// trampolines that require an executable stack.
299 virtual const MCSection *getNonexecutableStackSection(MCContext &Ctx) const{
303 bool usesSunStyleELFSectionSwitchSyntax() const {
304 return SunStyleELFSectionSwitchSyntax;
307 bool usesELFSectionDirectiveForBSS() const {
308 return UsesELFSectionDirectiveForBSS;
311 bool hasMicrosoftFastStdCallMangling() const {
312 return HasMicrosoftFastStdCallMangling;
317 bool hasMachoZeroFillDirective() const { return HasMachoZeroFillDirective; }
318 bool hasMachoTBSSDirective() const { return HasMachoTBSSDirective; }
319 bool hasStaticCtorDtorReferenceInStaticMode() const {
320 return HasStaticCtorDtorReferenceInStaticMode;
322 unsigned getMaxInstLength() const {
323 return MaxInstLength;
325 const char *getPCSymbol() const {
328 char getSeparatorChar() const {
329 return SeparatorChar;
331 unsigned getCommentColumn() const {
332 return CommentColumn;
334 const char *getCommentString() const {
335 return CommentString;
337 const char *getGlobalPrefix() const {
340 const char *getPrivateGlobalPrefix() const {
341 return PrivateGlobalPrefix;
343 const char *getLinkerPrivateGlobalPrefix() const {
344 return LinkerPrivateGlobalPrefix;
346 const char *getInlineAsmStart() const {
347 return InlineAsmStart;
349 const char *getInlineAsmEnd() const {
352 unsigned getAssemblerDialect() const {
353 return AssemblerDialect;
355 bool doesAllowQuotesInName() const {
356 return AllowQuotesInName;
358 bool doesAllowNameToStartWithDigit() const {
359 return AllowNameToStartWithDigit;
361 bool doesAllowPeriodsInName() const {
362 return AllowPeriodsInName;
364 const char *getZeroDirective() const {
365 return ZeroDirective;
367 const char *getAsciiDirective() const {
368 return AsciiDirective;
370 const char *getAscizDirective() const {
371 return AscizDirective;
373 const char *getAlignDirective() const {
374 return AlignDirective;
376 bool getAlignmentIsInBytes() const {
377 return AlignmentIsInBytes;
379 unsigned getTextAlignFillValue() const {
380 return TextAlignFillValue;
382 const char *getGlobalDirective() const {
383 return GlobalDirective;
385 const char *getExternDirective() const {
386 return ExternDirective;
388 bool hasSetDirective() const { return HasSetDirective; }
389 bool hasLCOMMDirective() const { return HasLCOMMDirective; }
390 bool hasDotTypeDotSizeDirective() const {return HasDotTypeDotSizeDirective;}
391 bool getCOMMDirectiveAlignmentIsInBytes() const {
392 return COMMDirectiveAlignmentIsInBytes;
394 bool hasSingleParameterDotFile() const { return HasSingleParameterDotFile; }
395 bool hasNoDeadStrip() const { return HasNoDeadStrip; }
396 const char *getWeakRefDirective() const { return WeakRefDirective; }
397 const char *getWeakDefDirective() const { return WeakDefDirective; }
398 const char *getLinkOnceDirective() const { return LinkOnceDirective; }
400 MCSymbolAttr getHiddenVisibilityAttr() const { return HiddenVisibilityAttr;}
401 MCSymbolAttr getProtectedVisibilityAttr() const {
402 return ProtectedVisibilityAttr;
404 bool hasLEB128() const {
407 bool hasDotLocAndDotFile() const {
408 return HasDotLocAndDotFile;
410 bool doesSupportDebugInformation() const {
411 return SupportsDebugInformation;
413 bool doesSupportExceptionHandling() const {
414 return ExceptionsType != ExceptionHandling::None;
416 ExceptionHandling::ExceptionsType getExceptionHandlingType() const {
417 return ExceptionsType;
419 bool doesDwarfRequireFrameSection() const {
420 return DwarfRequiresFrameSection;
422 bool doesDwarfUsesInlineInfoSection() const {
423 return DwarfUsesInlineInfoSection;
425 const char *getDwarfSectionOffsetDirective() const {
426 return DwarfSectionOffsetDirective;
428 bool doesDwarfUsesAbsoluteLabelForStmtList() const {
429 return DwarfUsesAbsoluteLabelForStmtList;
431 bool doesDwarfUsesLabelOffsetForRanges() const {
432 return DwarfUsesLabelOffsetForRanges;
434 const char *const *getAsmCBE() const {