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 /// JumpTableSpecialLabelPrefix - If not null, a extra (dead) label is
88 /// emitted before jump tables with the specified prefix.
89 const char *JumpTableSpecialLabelPrefix; // Default to null.
91 /// GlobalVarAddrPrefix/Suffix - If these are nonempty, these strings
92 /// will enclose any GlobalVariable (that isn't a function)
94 const char *GlobalVarAddrPrefix; // Defaults to ""
95 const char *GlobalVarAddrSuffix; // Defaults to ""
97 /// FunctionAddrPrefix/Suffix - If these are nonempty, these strings
98 /// will enclose any GlobalVariable that points to a function.
100 const char *FunctionAddrPrefix; // Defaults to ""
101 const char *FunctionAddrSuffix; // Defaults to ""
103 /// PersonalityPrefix/Suffix - If these are nonempty, these strings will
104 /// enclose any personality function in the common frame section.
106 const char *PersonalityPrefix; // Defaults to ""
107 const char *PersonalitySuffix; // Defaults to ""
109 /// NeedsIndirectEncoding - If set, we need to set the indirect encoding bit
112 bool NeedsIndirectEncoding; // Defaults to false
114 /// InlineAsmStart/End - If these are nonempty, they contain a directive to
115 /// emit before and after an inline assembly statement.
116 const char *InlineAsmStart; // Defaults to "#APP\n"
117 const char *InlineAsmEnd; // Defaults to "#NO_APP\n"
119 /// AssemblerDialect - Which dialect of an assembler variant to use.
120 unsigned AssemblerDialect; // Defaults to 0
122 /// AllowQuotesInName - This is true if the assembler allows for complex
123 /// symbol names to be surrounded in quotes. This defaults to false.
124 bool AllowQuotesInName;
126 //===--- Data Emission Directives -------------------------------------===//
128 /// ZeroDirective - this should be set to the directive used to get some
129 /// number of zero bytes emitted to the current section. Common cases are
130 /// "\t.zero\t" and "\t.space\t". If this is set to null, the
131 /// Data*bitsDirective's will be used to emit zero bytes.
132 const char *ZeroDirective; // Defaults to "\t.zero\t"
133 const char *ZeroDirectiveSuffix; // Defaults to ""
135 /// AsciiDirective - This directive allows emission of an ascii string with
136 /// the standard C escape characters embedded into it.
137 const char *AsciiDirective; // Defaults to "\t.ascii\t"
139 /// AscizDirective - If not null, this allows for special handling of
140 /// zero terminated strings on this target. This is commonly supported as
141 /// ".asciz". If a target doesn't support this, it can be set to null.
142 const char *AscizDirective; // Defaults to "\t.asciz\t"
144 /// DataDirectives - These directives are used to output some unit of
145 /// integer data to the current section. If a data directive is set to
146 /// null, smaller data directives will be used to emit the large sizes.
147 const char *Data8bitsDirective; // Defaults to "\t.byte\t"
148 const char *Data16bitsDirective; // Defaults to "\t.short\t"
149 const char *Data32bitsDirective; // Defaults to "\t.long\t"
150 const char *Data64bitsDirective; // Defaults to "\t.quad\t"
152 /// getDataASDirective - Return the directive that should be used to emit
153 /// data of the specified size to the specified numeric address space.
154 virtual const char *getDataASDirective(unsigned Size, unsigned AS) const {
155 assert(AS != 0 && "Don't know the directives for default addr space");
159 /// SunStyleELFSectionSwitchSyntax - This is true if this target uses "Sun
160 /// Style" syntax for section switching ("#alloc,#write" etc) instead of the
161 /// normal ELF syntax (,"a,w") in .section directives.
162 bool SunStyleELFSectionSwitchSyntax; // Defaults to false.
164 /// UsesELFSectionDirectiveForBSS - This is true if this target uses ELF
165 /// '.section' directive before the '.bss' one. It's used for PPC/Linux
166 /// which doesn't support the '.bss' directive only.
167 bool UsesELFSectionDirectiveForBSS; // 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 //===--- Section Switching Directives ---------------------------------===//
188 /// JumpTableDirective - if non-null, the directive to emit before jump
189 /// table entries. FIXME: REMOVE THIS.
190 const char *JumpTableDirective; // Defaults to NULL.
191 const char *PICJumpTableDirective; // Defaults to NULL.
194 //===--- Global Variable Emission Directives --------------------------===//
196 /// GlobalDirective - This is the directive used to declare a global entity.
198 const char *GlobalDirective; // Defaults to NULL.
200 /// ExternDirective - This is the directive used to declare external
203 const char *ExternDirective; // Defaults to NULL.
205 /// SetDirective - This is the name of a directive that can be used to tell
206 /// the assembler to set the value of a variable to some expression.
207 const char *SetDirective; // Defaults to null.
209 /// LCOMMDirective - This is the name of a directive (if supported) that can
210 /// be used to efficiently declare a local (internal) block of zero
211 /// initialized data in the .bss/.data section. The syntax expected is:
212 /// @verbatim <LCOMMDirective> SYMBOLNAME LENGTHINBYTES, ALIGNMENT
214 const char *LCOMMDirective; // Defaults to null.
216 const char *COMMDirective; // Defaults to "\t.comm\t".
218 /// COMMDirectiveTakesAlignment - True if COMMDirective take a third
219 /// argument that specifies the alignment of the declaration.
220 bool COMMDirectiveTakesAlignment; // Defaults to true.
222 /// HasDotTypeDotSizeDirective - True if the target has .type and .size
223 /// directives, this is true for most ELF targets.
224 bool HasDotTypeDotSizeDirective; // Defaults to true.
226 /// HasSingleParameterDotFile - True if the target has a single parameter
227 /// .file directive, this is true for ELF targets.
228 bool HasSingleParameterDotFile; // Defaults to true.
230 /// UsedDirective - This directive, if non-null, is used to declare a global
231 /// as being used somehow that the assembler can't see. This prevents dead
232 /// code elimination on some targets.
233 const char *UsedDirective; // Defaults to NULL.
235 /// WeakRefDirective - This directive, if non-null, is used to declare a
236 /// global as being a weak undefined symbol.
237 const char *WeakRefDirective; // Defaults to NULL.
239 /// WeakDefDirective - This directive, if non-null, is used to declare a
240 /// global as being a weak defined symbol.
241 const char *WeakDefDirective; // Defaults to NULL.
243 /// HiddenDirective - This directive, if non-null, is used to declare a
244 /// global or function as having hidden visibility.
245 const char *HiddenDirective; // Defaults to "\t.hidden\t".
247 /// ProtectedDirective - This directive, if non-null, is used to declare a
248 /// global or function as having protected visibility.
249 const char *ProtectedDirective; // Defaults to "\t.protected\t".
251 //===--- Dwarf Emission Directives -----------------------------------===//
253 /// AbsoluteDebugSectionOffsets - True if we should emit abolute section
254 /// offsets for debug information.
255 bool AbsoluteDebugSectionOffsets; // Defaults to false.
257 /// AbsoluteEHSectionOffsets - True if we should emit abolute section
258 /// offsets for EH information. Defaults to false.
259 bool AbsoluteEHSectionOffsets;
261 /// HasLEB128 - True if target asm supports leb128 directives.
262 bool HasLEB128; // Defaults to false.
264 /// hasDotLocAndDotFile - True if target asm supports .loc and .file
265 /// directives for emitting debugging information.
266 bool HasDotLocAndDotFile; // Defaults to false.
268 /// SupportsDebugInformation - True if target supports emission of debugging
270 bool SupportsDebugInformation; // Defaults to false.
272 /// SupportsExceptionHandling - True if target supports exception handling.
273 ExceptionHandling::ExceptionsType ExceptionsType; // Defaults to None
275 /// RequiresFrameSection - true if the Dwarf2 output needs a frame section
276 bool DwarfRequiresFrameSection; // Defaults to true.
278 /// DwarfUsesInlineInfoSection - True if DwarfDebugInlineSection is used to
279 /// encode inline subroutine information.
280 bool DwarfUsesInlineInfoSection; // Defaults to false.
282 /// Is_EHSymbolPrivate - If set, the "_foo.eh" is made private so that it
283 /// doesn't show up in the symbol table of the object file.
284 bool Is_EHSymbolPrivate; // Defaults to true.
286 /// GlobalEHDirective - This is the directive used to make exception frame
287 /// tables globally visible.
288 const char *GlobalEHDirective; // Defaults to NULL.
290 /// SupportsWeakEmptyEHFrame - True if target assembler and linker will
291 /// handle a weak_definition of constant 0 for an omitted EH frame.
292 bool SupportsWeakOmittedEHFrame; // Defaults to true.
294 /// DwarfSectionOffsetDirective - Special section offset directive.
295 const char* DwarfSectionOffsetDirective; // Defaults to NULL
297 //===--- CBE Asm Translation Table -----------------------------------===//
299 const char *const *AsmTransCBE; // Defaults to empty
302 explicit MCAsmInfo();
303 virtual ~MCAsmInfo();
305 /// getSLEB128Size - Compute the number of bytes required for a signed
307 static unsigned getSLEB128Size(int Value);
309 /// getULEB128Size - Compute the number of bytes required for an unsigned
311 static unsigned getULEB128Size(unsigned Value);
313 // Data directive accessors.
315 const char *getData8bitsDirective(unsigned AS = 0) const {
316 return AS == 0 ? Data8bitsDirective : getDataASDirective(8, AS);
318 const char *getData16bitsDirective(unsigned AS = 0) const {
319 return AS == 0 ? Data16bitsDirective : getDataASDirective(16, AS);
321 const char *getData32bitsDirective(unsigned AS = 0) const {
322 return AS == 0 ? Data32bitsDirective : getDataASDirective(32, AS);
324 const char *getData64bitsDirective(unsigned AS = 0) const {
325 return AS == 0 ? Data64bitsDirective : getDataASDirective(64, AS);
329 bool usesSunStyleELFSectionSwitchSyntax() const {
330 return SunStyleELFSectionSwitchSyntax;
333 bool usesELFSectionDirectiveForBSS() const {
334 return UsesELFSectionDirectiveForBSS;
339 const char *getZeroFillDirective() const {
340 return ZeroFillDirective;
342 const char *getNonexecutableStackDirective() const {
343 return NonexecutableStackDirective;
345 bool needsSet() const {
348 unsigned getMaxInstLength() const {
349 return MaxInstLength;
351 const char *getPCSymbol() const {
354 char getSeparatorChar() const {
355 return SeparatorChar;
357 unsigned getCommentColumn() const {
358 return CommentColumn;
360 const char *getCommentString() const {
361 return CommentString;
363 const char *getGlobalPrefix() const {
366 const char *getPrivateGlobalPrefix() const {
367 return PrivateGlobalPrefix;
369 const char *getLinkerPrivateGlobalPrefix() const {
370 return LinkerPrivateGlobalPrefix;
372 const char *getJumpTableSpecialLabelPrefix() const {
373 return JumpTableSpecialLabelPrefix;
375 const char *getGlobalVarAddrPrefix() const {
376 return GlobalVarAddrPrefix;
378 const char *getGlobalVarAddrSuffix() const {
379 return GlobalVarAddrSuffix;
381 const char *getFunctionAddrPrefix() const {
382 return FunctionAddrPrefix;
384 const char *getFunctionAddrSuffix() const {
385 return FunctionAddrSuffix;
387 const char *getPersonalityPrefix() const {
388 return PersonalityPrefix;
390 const char *getPersonalitySuffix() const {
391 return PersonalitySuffix;
393 bool getNeedsIndirectEncoding() const {
394 return NeedsIndirectEncoding;
396 const char *getInlineAsmStart() const {
397 return InlineAsmStart;
399 const char *getInlineAsmEnd() const {
402 unsigned getAssemblerDialect() const {
403 return AssemblerDialect;
405 bool doesAllowQuotesInName() const {
406 return AllowQuotesInName;
408 const char *getZeroDirective() const {
409 return ZeroDirective;
411 const char *getZeroDirectiveSuffix() const {
412 return ZeroDirectiveSuffix;
414 const char *getAsciiDirective() const {
415 return AsciiDirective;
417 const char *getAscizDirective() const {
418 return AscizDirective;
420 const char *getJumpTableDirective(bool isPIC) const {
421 return isPIC ? PICJumpTableDirective : JumpTableDirective;
423 const char *getAlignDirective() const {
424 return AlignDirective;
426 bool getAlignmentIsInBytes() const {
427 return AlignmentIsInBytes;
429 unsigned getTextAlignFillValue() const {
430 return TextAlignFillValue;
432 const char *getGlobalDirective() const {
433 return GlobalDirective;
435 const char *getExternDirective() const {
436 return ExternDirective;
438 const char *getSetDirective() const {
441 const char *getLCOMMDirective() const {
442 return LCOMMDirective;
444 const char *getCOMMDirective() const {
445 return COMMDirective;
447 bool getCOMMDirectiveTakesAlignment() const {
448 return COMMDirectiveTakesAlignment;
450 bool hasDotTypeDotSizeDirective() const {
451 return HasDotTypeDotSizeDirective;
453 bool hasSingleParameterDotFile() const {
454 return HasSingleParameterDotFile;
456 const char *getUsedDirective() const {
457 return UsedDirective;
459 const char *getWeakRefDirective() const {
460 return WeakRefDirective;
462 const char *getWeakDefDirective() const {
463 return WeakDefDirective;
465 const char *getHiddenDirective() const {
466 return HiddenDirective;
468 const char *getProtectedDirective() const {
469 return ProtectedDirective;
471 bool isAbsoluteDebugSectionOffsets() const {
472 return AbsoluteDebugSectionOffsets;
474 bool isAbsoluteEHSectionOffsets() const {
475 return AbsoluteEHSectionOffsets;
477 bool hasLEB128() const {
480 bool hasDotLocAndDotFile() const {
481 return HasDotLocAndDotFile;
483 bool doesSupportDebugInformation() const {
484 return SupportsDebugInformation;
486 bool doesSupportExceptionHandling() const {
487 return ExceptionsType != ExceptionHandling::None;
489 ExceptionHandling::ExceptionsType getExceptionHandlingType() const {
490 return ExceptionsType;
492 bool doesDwarfRequireFrameSection() const {
493 return DwarfRequiresFrameSection;
495 bool doesDwarfUsesInlineInfoSection() const {
496 return DwarfUsesInlineInfoSection;
498 bool is_EHSymbolPrivate() const {
499 return Is_EHSymbolPrivate;
501 const char *getGlobalEHDirective() const {
502 return GlobalEHDirective;
504 bool getSupportsWeakOmittedEHFrame() const {
505 return SupportsWeakOmittedEHFrame;
507 const char *getDwarfSectionOffsetDirective() const {
508 return DwarfSectionOffsetDirective;
510 const char *const *getAsmCBE() const {