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
22 /// MCAsmInfo - This class is intended to be used as a base class for asm
23 /// properties and features specific to the target.
24 namespace ExceptionHandling { enum ExceptionsType { None, Dwarf, SjLj }; }
28 //===------------------------------------------------------------------===//
29 // Properties to be set by the target writer, used to configure asm printer.
32 /// NonexecutableStackDirective - Directive for declaring to the
33 /// linker and beyond that the emitted code does not require stack
34 /// memory to be executable.
35 const char *NonexecutableStackDirective; // Default is null.
37 /// HasMachoZeroFillDirective - True if this is a MachO target that supports
38 /// the macho-specific .zerofill directive for emitting BSS Symbols.
39 bool HasMachoZeroFillDirective; // Default is false.
41 /// HasStaticCtorDtorReferenceInStaticMode - True if the compiler should
42 /// emit a ".reference .constructors_used" or ".reference .destructors_used"
43 /// directive after the a static ctor/dtor list. This directive is only
44 /// emitted in Static relocation model.
45 bool HasStaticCtorDtorReferenceInStaticMode; // Default is false.
47 /// NeedsSet - True if target asm treats expressions in data directives
48 /// as linktime-relocatable. For assembly-time computation, we need to
52 /// is computed at assembly time, while
54 /// is relocated if the relative locations of x and y change at linktime.
55 /// We want both these things in different places.
56 bool NeedsSet; // Defaults to false.
58 /// MaxInstLength - This is the maximum possible length of an instruction,
59 /// which is needed to compute the size of an inline asm.
60 unsigned MaxInstLength; // Defaults to 4.
62 /// PCSymbol - The symbol used to represent the current PC. Used in PC
63 /// relative expressions.
64 const char *PCSymbol; // Defaults to "$".
66 /// SeparatorChar - This character, if specified, is used to separate
67 /// instructions from each other when on the same line. This is used to
68 /// measure inline asm instructions.
69 char SeparatorChar; // Defaults to ';'
71 /// CommentColumn - This indicates the comment num (zero-based) at
72 /// which asm comments should be printed.
73 unsigned CommentColumn; // Defaults to 60
75 /// CommentString - This indicates the comment character used by the
77 const char *CommentString; // Defaults to "#"
79 /// GlobalPrefix - If this is set to a non-empty string, it is prepended
80 /// onto all global symbols. This is often used for "_" or ".".
81 const char *GlobalPrefix; // Defaults to ""
83 /// PrivateGlobalPrefix - This prefix is used for globals like constant
84 /// pool entries that are completely private to the .s file and should not
85 /// have names in the .o file. This is often "." or "L".
86 const char *PrivateGlobalPrefix; // Defaults to "."
88 /// LinkerPrivateGlobalPrefix - This prefix is used for symbols that should
89 /// be passed through the assembler but be removed by the linker. This
90 /// is "l" on Darwin, currently used for some ObjC metadata.
91 const char *LinkerPrivateGlobalPrefix; // Defaults to ""
93 /// InlineAsmStart/End - If these are nonempty, they contain a directive to
94 /// emit before and after an inline assembly statement.
95 const char *InlineAsmStart; // Defaults to "#APP\n"
96 const char *InlineAsmEnd; // Defaults to "#NO_APP\n"
98 /// AssemblerDialect - Which dialect of an assembler variant to use.
99 unsigned AssemblerDialect; // Defaults to 0
101 /// AllowQuotesInName - This is true if the assembler allows for complex
102 /// symbol names to be surrounded in quotes. This defaults to false.
103 bool AllowQuotesInName;
105 /// AllowNameToStartWithDigit - This is true if the assembler allows symbol
106 /// names to start with a digit (e.g., "0x0021"). This defaults to false.
107 bool AllowNameToStartWithDigit;
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 /// getDataASDirective - Return the directive that should be used to emit
135 /// data of the specified size to the specified numeric address space.
136 virtual const char *getDataASDirective(unsigned Size, unsigned AS) const {
137 assert(AS != 0 && "Don't know the directives for default addr space");
141 /// SunStyleELFSectionSwitchSyntax - This is true if this target uses "Sun
142 /// Style" syntax for section switching ("#alloc,#write" etc) instead of the
143 /// normal ELF syntax (,"a,w") in .section directives.
144 bool SunStyleELFSectionSwitchSyntax; // Defaults to false.
146 /// UsesELFSectionDirectiveForBSS - This is true if this target uses ELF
147 /// '.section' directive before the '.bss' one. It's used for PPC/Linux
148 /// which doesn't support the '.bss' directive only.
149 bool UsesELFSectionDirectiveForBSS; // Defaults to false.
151 //===--- Alignment Information ----------------------------------------===//
153 /// AlignDirective - The directive used to emit round up to an alignment
156 const char *AlignDirective; // Defaults to "\t.align\t"
158 /// AlignmentIsInBytes - If this is true (the default) then the asmprinter
159 /// emits ".align N" directives, where N is the number of bytes to align to.
160 /// Otherwise, it emits ".align log2(N)", e.g. 3 to align to an 8 byte
162 bool AlignmentIsInBytes; // Defaults to true
164 /// TextAlignFillValue - If non-zero, this is used to fill the executable
165 /// space created as the result of a alignment directive.
166 unsigned TextAlignFillValue; // Defaults to 0
168 //===--- Section Switching Directives ---------------------------------===//
170 /// JumpTableDirective - if non-null, the directive to emit before jump
171 /// table entries. FIXME: REMOVE THIS.
172 const char *JumpTableDirective; // Defaults to NULL.
173 const char *PICJumpTableDirective; // Defaults to NULL.
176 //===--- Global Variable Emission Directives --------------------------===//
178 /// GlobalDirective - This is the directive used to declare a global entity.
180 const char *GlobalDirective; // Defaults to NULL.
182 /// ExternDirective - This is the directive used to declare external
185 const char *ExternDirective; // Defaults to NULL.
187 /// SetDirective - This is the name of a directive that can be used to tell
188 /// the assembler to set the value of a variable to some expression.
189 const char *SetDirective; // Defaults to null.
191 /// LCOMMDirective - This is the name of a directive (if supported) that can
192 /// be used to efficiently declare a local (internal) block of zero
193 /// initialized data in the .bss/.data section. The syntax expected is:
194 /// @verbatim <LCOMMDirective> SYMBOLNAME LENGTHINBYTES
196 const char *LCOMMDirective; // Defaults to null.
198 const char *COMMDirective; // Defaults to "\t.comm\t".
200 /// COMMDirectiveTakesAlignment - True if COMMDirective take a third
201 /// argument that specifies the alignment of the declaration.
202 bool COMMDirectiveTakesAlignment; // Defaults to true.
204 /// HasDotTypeDotSizeDirective - True if the target has .type and .size
205 /// directives, this is true for most ELF targets.
206 bool HasDotTypeDotSizeDirective; // Defaults to true.
208 /// HasSingleParameterDotFile - True if the target has a single parameter
209 /// .file directive, this is true for ELF targets.
210 bool HasSingleParameterDotFile; // Defaults to true.
212 /// UsedDirective - This directive, if non-null, is used to declare a global
213 /// as being used somehow that the assembler can't see. This prevents dead
214 /// code elimination on some targets.
215 const char *UsedDirective; // Defaults to NULL.
217 /// WeakRefDirective - This directive, if non-null, is used to declare a
218 /// global as being a weak undefined symbol.
219 const char *WeakRefDirective; // Defaults to NULL.
221 /// WeakDefDirective - This directive, if non-null, is used to declare a
222 /// global as being a weak defined symbol.
223 const char *WeakDefDirective; // Defaults to NULL.
225 /// LinkOnceDirective - This directive, if non-null is used to declare a
226 /// global as being a weak defined symbol. This is used on cygwin/mingw.
227 const char *LinkOnceDirective; // Defaults to NULL.
229 /// HiddenDirective - This directive, if non-null, is used to declare a
230 /// global or function as having hidden visibility.
231 const char *HiddenDirective; // Defaults to "\t.hidden\t".
233 /// ProtectedDirective - This directive, if non-null, is used to declare a
234 /// global or function as having protected visibility.
235 const char *ProtectedDirective; // Defaults to "\t.protected\t".
237 //===--- Dwarf Emission Directives -----------------------------------===//
239 /// AbsoluteDebugSectionOffsets - True if we should emit abolute section
240 /// offsets for debug information.
241 bool AbsoluteDebugSectionOffsets; // Defaults to false.
243 /// AbsoluteEHSectionOffsets - True if we should emit abolute section
244 /// offsets for EH information. Defaults to false.
245 bool AbsoluteEHSectionOffsets;
247 /// HasLEB128 - True if target asm supports leb128 directives.
248 bool HasLEB128; // Defaults to false.
250 /// hasDotLocAndDotFile - True if target asm supports .loc and .file
251 /// directives for emitting debugging information.
252 bool HasDotLocAndDotFile; // Defaults to false.
254 /// SupportsDebugInformation - True if target supports emission of debugging
256 bool SupportsDebugInformation; // Defaults to false.
258 /// SupportsExceptionHandling - True if target supports exception handling.
259 ExceptionHandling::ExceptionsType ExceptionsType; // Defaults to None
261 /// RequiresFrameSection - true if the Dwarf2 output needs a frame section
262 bool DwarfRequiresFrameSection; // Defaults to true.
264 /// DwarfUsesInlineInfoSection - True if DwarfDebugInlineSection is used to
265 /// encode inline subroutine information.
266 bool DwarfUsesInlineInfoSection; // Defaults to false.
268 /// Is_EHSymbolPrivate - If set, the "_foo.eh" is made private so that it
269 /// doesn't show up in the symbol table of the object file.
270 bool Is_EHSymbolPrivate; // Defaults to true.
272 /// GlobalEHDirective - This is the directive used to make exception frame
273 /// tables globally visible.
274 const char *GlobalEHDirective; // Defaults to NULL.
276 /// SupportsWeakEmptyEHFrame - True if target assembler and linker will
277 /// handle a weak_definition of constant 0 for an omitted EH frame.
278 bool SupportsWeakOmittedEHFrame; // Defaults to true.
280 /// DwarfSectionOffsetDirective - Special section offset directive.
281 const char* DwarfSectionOffsetDirective; // Defaults to NULL
283 //===--- CBE Asm Translation Table -----------------------------------===//
285 const char *const *AsmTransCBE; // Defaults to empty
288 explicit MCAsmInfo();
289 virtual ~MCAsmInfo();
291 /// getSLEB128Size - Compute the number of bytes required for a signed
293 static unsigned getSLEB128Size(int Value);
295 /// getULEB128Size - Compute the number of bytes required for an unsigned
297 static unsigned getULEB128Size(unsigned Value);
299 // Data directive accessors.
301 const char *getData8bitsDirective(unsigned AS = 0) const {
302 return AS == 0 ? Data8bitsDirective : getDataASDirective(8, AS);
304 const char *getData16bitsDirective(unsigned AS = 0) const {
305 return AS == 0 ? Data16bitsDirective : getDataASDirective(16, AS);
307 const char *getData32bitsDirective(unsigned AS = 0) const {
308 return AS == 0 ? Data32bitsDirective : getDataASDirective(32, AS);
310 const char *getData64bitsDirective(unsigned AS = 0) const {
311 return AS == 0 ? Data64bitsDirective : getDataASDirective(64, AS);
315 bool usesSunStyleELFSectionSwitchSyntax() const {
316 return SunStyleELFSectionSwitchSyntax;
319 bool usesELFSectionDirectiveForBSS() const {
320 return UsesELFSectionDirectiveForBSS;
325 bool hasMachoZeroFillDirective() const { return HasMachoZeroFillDirective; }
326 bool hasStaticCtorDtorReferenceInStaticMode() const {
327 return HasStaticCtorDtorReferenceInStaticMode;
329 const char *getNonexecutableStackDirective() const {
330 return NonexecutableStackDirective;
332 bool needsSet() const {
335 unsigned getMaxInstLength() const {
336 return MaxInstLength;
338 const char *getPCSymbol() const {
341 char getSeparatorChar() const {
342 return SeparatorChar;
344 unsigned getCommentColumn() const {
345 return CommentColumn;
347 const char *getCommentString() const {
348 return CommentString;
350 const char *getGlobalPrefix() const {
353 const char *getPrivateGlobalPrefix() const {
354 return PrivateGlobalPrefix;
356 const char *getLinkerPrivateGlobalPrefix() const {
357 return LinkerPrivateGlobalPrefix;
359 const char *getInlineAsmStart() const {
360 return InlineAsmStart;
362 const char *getInlineAsmEnd() const {
365 unsigned getAssemblerDialect() const {
366 return AssemblerDialect;
368 bool doesAllowQuotesInName() const {
369 return AllowQuotesInName;
371 bool doesAllowNameToStartWithDigit() const {
372 return AllowNameToStartWithDigit;
374 const char *getZeroDirective() const {
375 return ZeroDirective;
377 const char *getAsciiDirective() const {
378 return AsciiDirective;
380 const char *getAscizDirective() const {
381 return AscizDirective;
383 const char *getJumpTableDirective(bool isPIC) const {
384 return isPIC ? PICJumpTableDirective : JumpTableDirective;
386 const char *getAlignDirective() const {
387 return AlignDirective;
389 bool getAlignmentIsInBytes() const {
390 return AlignmentIsInBytes;
392 unsigned getTextAlignFillValue() const {
393 return TextAlignFillValue;
395 const char *getGlobalDirective() const {
396 return GlobalDirective;
398 const char *getExternDirective() const {
399 return ExternDirective;
401 const char *getSetDirective() const {
404 const char *getLCOMMDirective() const {
405 return LCOMMDirective;
407 const char *getCOMMDirective() const {
408 return COMMDirective;
410 bool getCOMMDirectiveTakesAlignment() const {
411 return COMMDirectiveTakesAlignment;
413 bool hasDotTypeDotSizeDirective() const {
414 return HasDotTypeDotSizeDirective;
416 bool hasSingleParameterDotFile() const {
417 return HasSingleParameterDotFile;
419 const char *getUsedDirective() const {
420 return UsedDirective;
422 const char *getWeakRefDirective() const { return WeakRefDirective; }
423 const char *getWeakDefDirective() const { return WeakDefDirective; }
424 const char *getLinkOnceDirective() const { return LinkOnceDirective; }
425 const char *getHiddenDirective() const {
426 return HiddenDirective;
428 const char *getProtectedDirective() const {
429 return ProtectedDirective;
431 bool isAbsoluteDebugSectionOffsets() const {
432 return AbsoluteDebugSectionOffsets;
434 bool isAbsoluteEHSectionOffsets() const {
435 return AbsoluteEHSectionOffsets;
437 bool hasLEB128() const {
440 bool hasDotLocAndDotFile() const {
441 return HasDotLocAndDotFile;
443 bool doesSupportDebugInformation() const {
444 return SupportsDebugInformation;
446 bool doesSupportExceptionHandling() const {
447 return ExceptionsType != ExceptionHandling::None;
449 ExceptionHandling::ExceptionsType getExceptionHandlingType() const {
450 return ExceptionsType;
452 bool doesDwarfRequireFrameSection() const {
453 return DwarfRequiresFrameSection;
455 bool doesDwarfUsesInlineInfoSection() const {
456 return DwarfUsesInlineInfoSection;
458 bool is_EHSymbolPrivate() const {
459 return Is_EHSymbolPrivate;
461 const char *getGlobalEHDirective() const {
462 return GlobalEHDirective;
464 bool getSupportsWeakOmittedEHFrame() const {
465 return SupportsWeakOmittedEHFrame;
467 const char *getDwarfSectionOffsetDirective() const {
468 return DwarfSectionOffsetDirective;
470 const char *const *getAsmCBE() const {