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 /// PersonalityPrefix/Suffix - If these are nonempty, these strings will
88 /// enclose any personality function in the common frame section.
90 const char *PersonalityPrefix; // Defaults to ""
91 const char *PersonalitySuffix; // Defaults to ""
93 /// NeedsIndirectEncoding - If set, we need to set the indirect encoding bit
96 bool NeedsIndirectEncoding; // Defaults to false
98 /// InlineAsmStart/End - If these are nonempty, they contain a directive to
99 /// emit before and after an inline assembly statement.
100 const char *InlineAsmStart; // Defaults to "#APP\n"
101 const char *InlineAsmEnd; // Defaults to "#NO_APP\n"
103 /// AssemblerDialect - Which dialect of an assembler variant to use.
104 unsigned AssemblerDialect; // Defaults to 0
106 /// AllowQuotesInName - This is true if the assembler allows for complex
107 /// symbol names to be surrounded in quotes. This defaults to false.
108 bool AllowQuotesInName;
110 //===--- Data Emission Directives -------------------------------------===//
112 /// ZeroDirective - this should be set to the directive used to get some
113 /// number of zero bytes emitted to the current section. Common cases are
114 /// "\t.zero\t" and "\t.space\t". If this is set to null, the
115 /// Data*bitsDirective's will be used to emit zero bytes.
116 const char *ZeroDirective; // Defaults to "\t.zero\t"
117 const char *ZeroDirectiveSuffix; // Defaults to ""
119 /// AsciiDirective - This directive allows emission of an ascii string with
120 /// the standard C escape characters embedded into it.
121 const char *AsciiDirective; // Defaults to "\t.ascii\t"
123 /// AscizDirective - If not null, this allows for special handling of
124 /// zero terminated strings on this target. This is commonly supported as
125 /// ".asciz". If a target doesn't support this, it can be set to null.
126 const char *AscizDirective; // Defaults to "\t.asciz\t"
128 /// DataDirectives - These directives are used to output some unit of
129 /// integer data to the current section. If a data directive is set to
130 /// null, smaller data directives will be used to emit the large sizes.
131 const char *Data8bitsDirective; // Defaults to "\t.byte\t"
132 const char *Data16bitsDirective; // Defaults to "\t.short\t"
133 const char *Data32bitsDirective; // Defaults to "\t.long\t"
134 const char *Data64bitsDirective; // Defaults to "\t.quad\t"
136 /// getDataASDirective - Return the directive that should be used to emit
137 /// data of the specified size to the specified numeric address space.
138 virtual const char *getDataASDirective(unsigned Size, unsigned AS) const {
139 assert(AS != 0 && "Don't know the directives for default addr space");
143 /// SunStyleELFSectionSwitchSyntax - This is true if this target uses "Sun
144 /// Style" syntax for section switching ("#alloc,#write" etc) instead of the
145 /// normal ELF syntax (,"a,w") in .section directives.
146 bool SunStyleELFSectionSwitchSyntax; // Defaults to false.
148 /// UsesELFSectionDirectiveForBSS - This is true if this target uses ELF
149 /// '.section' directive before the '.bss' one. It's used for PPC/Linux
150 /// which doesn't support the '.bss' directive only.
151 bool UsesELFSectionDirectiveForBSS; // Defaults to false.
153 //===--- Alignment Information ----------------------------------------===//
155 /// AlignDirective - The directive used to emit round up to an alignment
158 const char *AlignDirective; // Defaults to "\t.align\t"
160 /// AlignmentIsInBytes - If this is true (the default) then the asmprinter
161 /// emits ".align N" directives, where N is the number of bytes to align to.
162 /// Otherwise, it emits ".align log2(N)", e.g. 3 to align to an 8 byte
164 bool AlignmentIsInBytes; // Defaults to true
166 /// TextAlignFillValue - If non-zero, this is used to fill the executable
167 /// space created as the result of a alignment directive.
168 unsigned TextAlignFillValue; // Defaults to 0
170 //===--- Section Switching Directives ---------------------------------===//
172 /// JumpTableDirective - if non-null, the directive to emit before jump
173 /// table entries. FIXME: REMOVE THIS.
174 const char *JumpTableDirective; // Defaults to NULL.
175 const char *PICJumpTableDirective; // Defaults to NULL.
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 /// SetDirective - This is the name of a directive that can be used to tell
190 /// the assembler to set the value of a variable to some expression.
191 const char *SetDirective; // Defaults to null.
193 /// LCOMMDirective - This is the name of a directive (if supported) that can
194 /// be used to efficiently declare a local (internal) block of zero
195 /// initialized data in the .bss/.data section. The syntax expected is:
196 /// @verbatim <LCOMMDirective> SYMBOLNAME LENGTHINBYTES, ALIGNMENT
198 const char *LCOMMDirective; // Defaults to null.
200 const char *COMMDirective; // Defaults to "\t.comm\t".
202 /// COMMDirectiveTakesAlignment - True if COMMDirective take a third
203 /// argument that specifies the alignment of the declaration.
204 bool COMMDirectiveTakesAlignment; // Defaults to true.
206 /// HasDotTypeDotSizeDirective - True if the target has .type and .size
207 /// directives, this is true for most ELF targets.
208 bool HasDotTypeDotSizeDirective; // Defaults to true.
210 /// HasSingleParameterDotFile - True if the target has a single parameter
211 /// .file directive, this is true for ELF targets.
212 bool HasSingleParameterDotFile; // Defaults to true.
214 /// UsedDirective - This directive, if non-null, is used to declare a global
215 /// as being used somehow that the assembler can't see. This prevents dead
216 /// code elimination on some targets.
217 const char *UsedDirective; // Defaults to NULL.
219 /// WeakRefDirective - This directive, if non-null, is used to declare a
220 /// global as being a weak undefined symbol.
221 const char *WeakRefDirective; // Defaults to NULL.
223 /// WeakDefDirective - This directive, if non-null, is used to declare a
224 /// global as being a weak defined symbol.
225 const char *WeakDefDirective; // Defaults to NULL.
227 /// HiddenDirective - This directive, if non-null, is used to declare a
228 /// global or function as having hidden visibility.
229 const char *HiddenDirective; // Defaults to "\t.hidden\t".
231 /// ProtectedDirective - This directive, if non-null, is used to declare a
232 /// global or function as having protected visibility.
233 const char *ProtectedDirective; // Defaults to "\t.protected\t".
235 //===--- Dwarf Emission Directives -----------------------------------===//
237 /// AbsoluteDebugSectionOffsets - True if we should emit abolute section
238 /// offsets for debug information.
239 bool AbsoluteDebugSectionOffsets; // Defaults to false.
241 /// AbsoluteEHSectionOffsets - True if we should emit abolute section
242 /// offsets for EH information. Defaults to false.
243 bool AbsoluteEHSectionOffsets;
245 /// HasLEB128 - True if target asm supports leb128 directives.
246 bool HasLEB128; // Defaults to false.
248 /// hasDotLocAndDotFile - True if target asm supports .loc and .file
249 /// directives for emitting debugging information.
250 bool HasDotLocAndDotFile; // Defaults to false.
252 /// SupportsDebugInformation - True if target supports emission of debugging
254 bool SupportsDebugInformation; // Defaults to false.
256 /// SupportsExceptionHandling - True if target supports exception handling.
257 ExceptionHandling::ExceptionsType ExceptionsType; // Defaults to None
259 /// RequiresFrameSection - true if the Dwarf2 output needs a frame section
260 bool DwarfRequiresFrameSection; // Defaults to true.
262 /// DwarfUsesInlineInfoSection - True if DwarfDebugInlineSection is used to
263 /// encode inline subroutine information.
264 bool DwarfUsesInlineInfoSection; // Defaults to false.
266 /// Is_EHSymbolPrivate - If set, the "_foo.eh" is made private so that it
267 /// doesn't show up in the symbol table of the object file.
268 bool Is_EHSymbolPrivate; // Defaults to true.
270 /// GlobalEHDirective - This is the directive used to make exception frame
271 /// tables globally visible.
272 const char *GlobalEHDirective; // Defaults to NULL.
274 /// SupportsWeakEmptyEHFrame - True if target assembler and linker will
275 /// handle a weak_definition of constant 0 for an omitted EH frame.
276 bool SupportsWeakOmittedEHFrame; // Defaults to true.
278 /// DwarfSectionOffsetDirective - Special section offset directive.
279 const char* DwarfSectionOffsetDirective; // Defaults to NULL
281 //===--- CBE Asm Translation Table -----------------------------------===//
283 const char *const *AsmTransCBE; // Defaults to empty
286 explicit MCAsmInfo();
287 virtual ~MCAsmInfo();
289 /// getSLEB128Size - Compute the number of bytes required for a signed
291 static unsigned getSLEB128Size(int Value);
293 /// getULEB128Size - Compute the number of bytes required for an unsigned
295 static unsigned getULEB128Size(unsigned Value);
297 // Data directive accessors.
299 const char *getData8bitsDirective(unsigned AS = 0) const {
300 return AS == 0 ? Data8bitsDirective : getDataASDirective(8, AS);
302 const char *getData16bitsDirective(unsigned AS = 0) const {
303 return AS == 0 ? Data16bitsDirective : getDataASDirective(16, AS);
305 const char *getData32bitsDirective(unsigned AS = 0) const {
306 return AS == 0 ? Data32bitsDirective : getDataASDirective(32, AS);
308 const char *getData64bitsDirective(unsigned AS = 0) const {
309 return AS == 0 ? Data64bitsDirective : getDataASDirective(64, AS);
313 bool usesSunStyleELFSectionSwitchSyntax() const {
314 return SunStyleELFSectionSwitchSyntax;
317 bool usesELFSectionDirectiveForBSS() const {
318 return UsesELFSectionDirectiveForBSS;
323 const char *getZeroFillDirective() const {
324 return ZeroFillDirective;
326 const char *getNonexecutableStackDirective() const {
327 return NonexecutableStackDirective;
329 bool needsSet() const {
332 unsigned getMaxInstLength() const {
333 return MaxInstLength;
335 const char *getPCSymbol() const {
338 char getSeparatorChar() const {
339 return SeparatorChar;
341 unsigned getCommentColumn() const {
342 return CommentColumn;
344 const char *getCommentString() const {
345 return CommentString;
347 const char *getGlobalPrefix() const {
350 const char *getPrivateGlobalPrefix() const {
351 return PrivateGlobalPrefix;
353 const char *getLinkerPrivateGlobalPrefix() const {
354 return LinkerPrivateGlobalPrefix;
356 const char *getPersonalityPrefix() const {
357 return PersonalityPrefix;
359 const char *getPersonalitySuffix() const {
360 return PersonalitySuffix;
362 bool getNeedsIndirectEncoding() const {
363 return NeedsIndirectEncoding;
365 const char *getInlineAsmStart() const {
366 return InlineAsmStart;
368 const char *getInlineAsmEnd() const {
371 unsigned getAssemblerDialect() const {
372 return AssemblerDialect;
374 bool doesAllowQuotesInName() const {
375 return AllowQuotesInName;
377 const char *getZeroDirective() const {
378 return ZeroDirective;
380 const char *getZeroDirectiveSuffix() const {
381 return ZeroDirectiveSuffix;
383 const char *getAsciiDirective() const {
384 return AsciiDirective;
386 const char *getAscizDirective() const {
387 return AscizDirective;
389 const char *getJumpTableDirective(bool isPIC) const {
390 return isPIC ? PICJumpTableDirective : JumpTableDirective;
392 const char *getAlignDirective() const {
393 return AlignDirective;
395 bool getAlignmentIsInBytes() const {
396 return AlignmentIsInBytes;
398 unsigned getTextAlignFillValue() const {
399 return TextAlignFillValue;
401 const char *getGlobalDirective() const {
402 return GlobalDirective;
404 const char *getExternDirective() const {
405 return ExternDirective;
407 const char *getSetDirective() const {
410 const char *getLCOMMDirective() const {
411 return LCOMMDirective;
413 const char *getCOMMDirective() const {
414 return COMMDirective;
416 bool getCOMMDirectiveTakesAlignment() const {
417 return COMMDirectiveTakesAlignment;
419 bool hasDotTypeDotSizeDirective() const {
420 return HasDotTypeDotSizeDirective;
422 bool hasSingleParameterDotFile() const {
423 return HasSingleParameterDotFile;
425 const char *getUsedDirective() const {
426 return UsedDirective;
428 const char *getWeakRefDirective() const {
429 return WeakRefDirective;
431 const char *getWeakDefDirective() const {
432 return WeakDefDirective;
434 const char *getHiddenDirective() const {
435 return HiddenDirective;
437 const char *getProtectedDirective() const {
438 return ProtectedDirective;
440 bool isAbsoluteDebugSectionOffsets() const {
441 return AbsoluteDebugSectionOffsets;
443 bool isAbsoluteEHSectionOffsets() const {
444 return AbsoluteEHSectionOffsets;
446 bool hasLEB128() const {
449 bool hasDotLocAndDotFile() const {
450 return HasDotLocAndDotFile;
452 bool doesSupportDebugInformation() const {
453 return SupportsDebugInformation;
455 bool doesSupportExceptionHandling() const {
456 return ExceptionsType != ExceptionHandling::None;
458 ExceptionHandling::ExceptionsType getExceptionHandlingType() const {
459 return ExceptionsType;
461 bool doesDwarfRequireFrameSection() const {
462 return DwarfRequiresFrameSection;
464 bool doesDwarfUsesInlineInfoSection() const {
465 return DwarfUsesInlineInfoSection;
467 bool is_EHSymbolPrivate() const {
468 return Is_EHSymbolPrivate;
470 const char *getGlobalEHDirective() const {
471 return GlobalEHDirective;
473 bool getSupportsWeakOmittedEHFrame() const {
474 return SupportsWeakOmittedEHFrame;
476 const char *getDwarfSectionOffsetDirective() const {
477 return DwarfSectionOffsetDirective;
479 const char *const *getAsmCBE() const {