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 /// ZeroFillDirective - Directive for emitting a global to the ZeroFill
33 /// section on this target. Null if this target doesn't support zerofill.
34 const char *ZeroFillDirective; // Default is null.
36 /// NonexecutableStackDirective - Directive for declaring to the
37 /// linker and beyond that the emitted code does not require stack
38 /// memory to be executable.
39 const char *NonexecutableStackDirective; // Default is null.
41 /// NeedsSet - True if target asm treats expressions in data directives
42 /// as linktime-relocatable. For assembly-time computation, we need to
46 /// is computed at assembly time, while
48 /// is relocated if the relative locations of x and y change at linktime.
49 /// We want both these things in different places.
50 bool NeedsSet; // Defaults to false.
52 /// MaxInstLength - This is the maximum possible length of an instruction,
53 /// which is needed to compute the size of an inline asm.
54 unsigned MaxInstLength; // Defaults to 4.
56 /// PCSymbol - The symbol used to represent the current PC. Used in PC
57 /// relative expressions.
58 const char *PCSymbol; // Defaults to "$".
60 /// SeparatorChar - This character, if specified, is used to separate
61 /// instructions from each other when on the same line. This is used to
62 /// measure inline asm instructions.
63 char SeparatorChar; // Defaults to ';'
65 /// CommentColumn - This indicates the comment num (zero-based) at
66 /// which asm comments should be printed.
67 unsigned CommentColumn; // Defaults to 60
69 /// CommentString - This indicates the comment character used by the
71 const char *CommentString; // Defaults to "#"
73 /// GlobalPrefix - If this is set to a non-empty string, it is prepended
74 /// onto all global symbols. This is often used for "_" or ".".
75 const char *GlobalPrefix; // Defaults to ""
77 /// PrivateGlobalPrefix - This prefix is used for globals like constant
78 /// pool entries that are completely private to the .s file and should not
79 /// have names in the .o file. This is often "." or "L".
80 const char *PrivateGlobalPrefix; // Defaults to "."
82 /// LinkerPrivateGlobalPrefix - This prefix is used for symbols that should
83 /// be passed through the assembler but be removed by the linker. This
84 /// is "l" on Darwin, currently used for some ObjC metadata.
85 const char *LinkerPrivateGlobalPrefix; // Defaults to ""
87 /// GlobalVarAddrPrefix/Suffix - If these are nonempty, these strings
88 /// will enclose any GlobalVariable (that isn't a function)
90 const char *GlobalVarAddrPrefix; // Defaults to ""
91 const char *GlobalVarAddrSuffix; // Defaults to ""
93 /// FunctionAddrPrefix/Suffix - If these are nonempty, these strings
94 /// will enclose any GlobalVariable that points to a function.
96 const char *FunctionAddrPrefix; // Defaults to ""
97 const char *FunctionAddrSuffix; // Defaults to ""
99 /// PersonalityPrefix/Suffix - If these are nonempty, these strings will
100 /// enclose any personality function in the common frame section.
102 const char *PersonalityPrefix; // Defaults to ""
103 const char *PersonalitySuffix; // Defaults to ""
105 /// NeedsIndirectEncoding - If set, we need to set the indirect encoding bit
108 bool NeedsIndirectEncoding; // Defaults to false
110 /// InlineAsmStart/End - If these are nonempty, they contain a directive to
111 /// emit before and after an inline assembly statement.
112 const char *InlineAsmStart; // Defaults to "#APP\n"
113 const char *InlineAsmEnd; // Defaults to "#NO_APP\n"
115 /// AssemblerDialect - Which dialect of an assembler variant to use.
116 unsigned AssemblerDialect; // Defaults to 0
118 /// AllowQuotesInName - This is true if the assembler allows for complex
119 /// symbol names to be surrounded in quotes. This defaults to false.
120 bool AllowQuotesInName;
122 //===--- Data Emission Directives -------------------------------------===//
124 /// ZeroDirective - this should be set to the directive used to get some
125 /// number of zero bytes emitted to the current section. Common cases are
126 /// "\t.zero\t" and "\t.space\t". If this is set to null, the
127 /// Data*bitsDirective's will be used to emit zero bytes.
128 const char *ZeroDirective; // Defaults to "\t.zero\t"
129 const char *ZeroDirectiveSuffix; // Defaults to ""
131 /// AsciiDirective - This directive allows emission of an ascii string with
132 /// the standard C escape characters embedded into it.
133 const char *AsciiDirective; // Defaults to "\t.ascii\t"
135 /// AscizDirective - If not null, this allows for special handling of
136 /// zero terminated strings on this target. This is commonly supported as
137 /// ".asciz". If a target doesn't support this, it can be set to null.
138 const char *AscizDirective; // Defaults to "\t.asciz\t"
140 /// DataDirectives - These directives are used to output some unit of
141 /// integer data to the current section. If a data directive is set to
142 /// null, smaller data directives will be used to emit the large sizes.
143 const char *Data8bitsDirective; // Defaults to "\t.byte\t"
144 const char *Data16bitsDirective; // Defaults to "\t.short\t"
145 const char *Data32bitsDirective; // Defaults to "\t.long\t"
146 const char *Data64bitsDirective; // Defaults to "\t.quad\t"
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 //===--- Alignment Information ----------------------------------------===//
167 /// AlignDirective - The directive used to emit round up to an alignment
170 const char *AlignDirective; // Defaults to "\t.align\t"
172 /// AlignmentIsInBytes - If this is true (the default) then the asmprinter
173 /// emits ".align N" directives, where N is the number of bytes to align to.
174 /// Otherwise, it emits ".align log2(N)", e.g. 3 to align to an 8 byte
176 bool AlignmentIsInBytes; // Defaults to true
178 /// TextAlignFillValue - If non-zero, this is used to fill the executable
179 /// space created as the result of a alignment directive.
180 unsigned TextAlignFillValue; // Defaults to 0
182 //===--- Section Switching Directives ---------------------------------===//
184 /// JumpTableDirective - if non-null, the directive to emit before jump
185 /// table entries. FIXME: REMOVE THIS.
186 const char *JumpTableDirective; // Defaults to NULL.
187 const char *PICJumpTableDirective; // Defaults to NULL.
190 //===--- Global Variable Emission Directives --------------------------===//
192 /// GlobalDirective - This is the directive used to declare a global entity.
194 const char *GlobalDirective; // Defaults to NULL.
196 /// ExternDirective - This is the directive used to declare external
199 const char *ExternDirective; // Defaults to NULL.
201 /// SetDirective - This is the name of a directive that can be used to tell
202 /// the assembler to set the value of a variable to some expression.
203 const char *SetDirective; // Defaults to null.
205 /// LCOMMDirective - This is the name of a directive (if supported) that can
206 /// be used to efficiently declare a local (internal) block of zero
207 /// initialized data in the .bss/.data section. The syntax expected is:
208 /// @verbatim <LCOMMDirective> SYMBOLNAME LENGTHINBYTES, ALIGNMENT
210 const char *LCOMMDirective; // Defaults to null.
212 const char *COMMDirective; // Defaults to "\t.comm\t".
214 /// COMMDirectiveTakesAlignment - True if COMMDirective take a third
215 /// argument that specifies the alignment of the declaration.
216 bool COMMDirectiveTakesAlignment; // Defaults to true.
218 /// HasDotTypeDotSizeDirective - True if the target has .type and .size
219 /// directives, this is true for most ELF targets.
220 bool HasDotTypeDotSizeDirective; // Defaults to true.
222 /// HasSingleParameterDotFile - True if the target has a single parameter
223 /// .file directive, this is true for ELF targets.
224 bool HasSingleParameterDotFile; // Defaults to true.
226 /// UsedDirective - This directive, if non-null, is used to declare a global
227 /// as being used somehow that the assembler can't see. This prevents dead
228 /// code elimination on some targets.
229 const char *UsedDirective; // Defaults to NULL.
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 /// HiddenDirective - This directive, if non-null, is used to declare a
240 /// global or function as having hidden visibility.
241 const char *HiddenDirective; // Defaults to "\t.hidden\t".
243 /// ProtectedDirective - This directive, if non-null, is used to declare a
244 /// global or function as having protected visibility.
245 const char *ProtectedDirective; // Defaults to "\t.protected\t".
247 //===--- Dwarf Emission Directives -----------------------------------===//
249 /// AbsoluteDebugSectionOffsets - True if we should emit abolute section
250 /// offsets for debug information.
251 bool AbsoluteDebugSectionOffsets; // Defaults to false.
253 /// AbsoluteEHSectionOffsets - True if we should emit abolute section
254 /// offsets for EH information. Defaults to false.
255 bool AbsoluteEHSectionOffsets;
257 /// HasLEB128 - True if target asm supports leb128 directives.
258 bool HasLEB128; // Defaults to false.
260 /// hasDotLocAndDotFile - True if target asm supports .loc and .file
261 /// directives for emitting debugging information.
262 bool HasDotLocAndDotFile; // Defaults to false.
264 /// SupportsDebugInformation - True if target supports emission of debugging
266 bool SupportsDebugInformation; // Defaults to false.
268 /// SupportsExceptionHandling - True if target supports exception handling.
269 ExceptionHandling::ExceptionsType ExceptionsType; // Defaults to None
271 /// RequiresFrameSection - true if the Dwarf2 output needs a frame section
272 bool DwarfRequiresFrameSection; // Defaults to true.
274 /// DwarfUsesInlineInfoSection - True if DwarfDebugInlineSection is used to
275 /// encode inline subroutine information.
276 bool DwarfUsesInlineInfoSection; // Defaults to false.
278 /// Is_EHSymbolPrivate - If set, the "_foo.eh" is made private so that it
279 /// doesn't show up in the symbol table of the object file.
280 bool Is_EHSymbolPrivate; // Defaults to true.
282 /// GlobalEHDirective - This is the directive used to make exception frame
283 /// tables globally visible.
284 const char *GlobalEHDirective; // Defaults to NULL.
286 /// SupportsWeakEmptyEHFrame - True if target assembler and linker will
287 /// handle a weak_definition of constant 0 for an omitted EH frame.
288 bool SupportsWeakOmittedEHFrame; // Defaults to true.
290 /// DwarfSectionOffsetDirective - Special section offset directive.
291 const char* DwarfSectionOffsetDirective; // Defaults to NULL
293 //===--- CBE Asm Translation Table -----------------------------------===//
295 const char *const *AsmTransCBE; // Defaults to empty
298 explicit MCAsmInfo();
299 virtual ~MCAsmInfo();
301 /// getSLEB128Size - Compute the number of bytes required for a signed
303 static unsigned getSLEB128Size(int Value);
305 /// getULEB128Size - Compute the number of bytes required for an unsigned
307 static unsigned getULEB128Size(unsigned Value);
309 // Data directive accessors.
311 const char *getData8bitsDirective(unsigned AS = 0) const {
312 return AS == 0 ? Data8bitsDirective : getDataASDirective(8, AS);
314 const char *getData16bitsDirective(unsigned AS = 0) const {
315 return AS == 0 ? Data16bitsDirective : getDataASDirective(16, AS);
317 const char *getData32bitsDirective(unsigned AS = 0) const {
318 return AS == 0 ? Data32bitsDirective : getDataASDirective(32, AS);
320 const char *getData64bitsDirective(unsigned AS = 0) const {
321 return AS == 0 ? Data64bitsDirective : getDataASDirective(64, AS);
325 bool usesSunStyleELFSectionSwitchSyntax() const {
326 return SunStyleELFSectionSwitchSyntax;
329 bool usesELFSectionDirectiveForBSS() const {
330 return UsesELFSectionDirectiveForBSS;
335 const char *getZeroFillDirective() const {
336 return ZeroFillDirective;
338 const char *getNonexecutableStackDirective() const {
339 return NonexecutableStackDirective;
341 bool needsSet() const {
344 unsigned getMaxInstLength() const {
345 return MaxInstLength;
347 const char *getPCSymbol() const {
350 char getSeparatorChar() const {
351 return SeparatorChar;
353 unsigned getCommentColumn() const {
354 return CommentColumn;
356 const char *getCommentString() const {
357 return CommentString;
359 const char *getGlobalPrefix() const {
362 const char *getPrivateGlobalPrefix() const {
363 return PrivateGlobalPrefix;
365 const char *getLinkerPrivateGlobalPrefix() const {
366 return LinkerPrivateGlobalPrefix;
368 const char *getGlobalVarAddrPrefix() const {
369 return GlobalVarAddrPrefix;
371 const char *getGlobalVarAddrSuffix() const {
372 return GlobalVarAddrSuffix;
374 const char *getFunctionAddrPrefix() const {
375 return FunctionAddrPrefix;
377 const char *getFunctionAddrSuffix() const {
378 return FunctionAddrSuffix;
380 const char *getPersonalityPrefix() const {
381 return PersonalityPrefix;
383 const char *getPersonalitySuffix() const {
384 return PersonalitySuffix;
386 bool getNeedsIndirectEncoding() const {
387 return NeedsIndirectEncoding;
389 const char *getInlineAsmStart() const {
390 return InlineAsmStart;
392 const char *getInlineAsmEnd() const {
395 unsigned getAssemblerDialect() const {
396 return AssemblerDialect;
398 bool doesAllowQuotesInName() const {
399 return AllowQuotesInName;
401 const char *getZeroDirective() const {
402 return ZeroDirective;
404 const char *getZeroDirectiveSuffix() const {
405 return ZeroDirectiveSuffix;
407 const char *getAsciiDirective() const {
408 return AsciiDirective;
410 const char *getAscizDirective() const {
411 return AscizDirective;
413 const char *getJumpTableDirective(bool isPIC) const {
414 return isPIC ? PICJumpTableDirective : JumpTableDirective;
416 const char *getAlignDirective() const {
417 return AlignDirective;
419 bool getAlignmentIsInBytes() const {
420 return AlignmentIsInBytes;
422 unsigned getTextAlignFillValue() const {
423 return TextAlignFillValue;
425 const char *getGlobalDirective() const {
426 return GlobalDirective;
428 const char *getExternDirective() const {
429 return ExternDirective;
431 const char *getSetDirective() const {
434 const char *getLCOMMDirective() const {
435 return LCOMMDirective;
437 const char *getCOMMDirective() const {
438 return COMMDirective;
440 bool getCOMMDirectiveTakesAlignment() const {
441 return COMMDirectiveTakesAlignment;
443 bool hasDotTypeDotSizeDirective() const {
444 return HasDotTypeDotSizeDirective;
446 bool hasSingleParameterDotFile() const {
447 return HasSingleParameterDotFile;
449 const char *getUsedDirective() const {
450 return UsedDirective;
452 const char *getWeakRefDirective() const {
453 return WeakRefDirective;
455 const char *getWeakDefDirective() const {
456 return WeakDefDirective;
458 const char *getHiddenDirective() const {
459 return HiddenDirective;
461 const char *getProtectedDirective() const {
462 return ProtectedDirective;
464 bool isAbsoluteDebugSectionOffsets() const {
465 return AbsoluteDebugSectionOffsets;
467 bool isAbsoluteEHSectionOffsets() const {
468 return AbsoluteEHSectionOffsets;
470 bool hasLEB128() const {
473 bool hasDotLocAndDotFile() const {
474 return HasDotLocAndDotFile;
476 bool doesSupportDebugInformation() const {
477 return SupportsDebugInformation;
479 bool doesSupportExceptionHandling() const {
480 return ExceptionsType != ExceptionHandling::None;
482 ExceptionHandling::ExceptionsType getExceptionHandlingType() const {
483 return ExceptionsType;
485 bool doesDwarfRequireFrameSection() const {
486 return DwarfRequiresFrameSection;
488 bool doesDwarfUsesInlineInfoSection() const {
489 return DwarfUsesInlineInfoSection;
491 bool is_EHSymbolPrivate() const {
492 return Is_EHSymbolPrivate;
494 const char *getGlobalEHDirective() const {
495 return GlobalEHDirective;
497 bool getSupportsWeakOmittedEHFrame() const {
498 return SupportsWeakOmittedEHFrame;
500 const char *getDwarfSectionOffsetDirective() const {
501 return DwarfSectionOffsetDirective;
503 const char *const *getAsmCBE() const {