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/Support/DataTypes.h"
23 template <typename T> class SmallVectorImpl;
25 /// MCAsmInfo - This class is intended to be used as a base class for asm
26 /// properties and features specific to the target.
27 namespace ExceptionHandling { enum ExceptionsType { None, Dwarf, SjLj }; }
31 //===------------------------------------------------------------------===//
32 // Properties to be set by the target writer, used to configure asm printer.
35 /// ZeroFillDirective - Directive for emitting a global to the ZeroFill
36 /// section on this target. Null if this target doesn't support zerofill.
37 const char *ZeroFillDirective; // Default is null.
39 /// NonexecutableStackDirective - Directive for declaring to the
40 /// linker and beyond that the emitted code does not require stack
41 /// memory to be executable.
42 const char *NonexecutableStackDirective; // Default is null.
44 /// NeedsSet - True if target asm treats expressions in data directives
45 /// as linktime-relocatable. For assembly-time computation, we need to
49 /// is computed at assembly time, while
51 /// is relocated if the relative locations of x and y change at linktime.
52 /// We want both these things in different places.
53 bool NeedsSet; // Defaults to false.
55 /// MaxInstLength - This is the maximum possible length of an instruction,
56 /// which is needed to compute the size of an inline asm.
57 unsigned MaxInstLength; // Defaults to 4.
59 /// PCSymbol - The symbol used to represent the current PC. Used in PC
60 /// relative expressions.
61 const char *PCSymbol; // Defaults to "$".
63 /// SeparatorChar - This character, if specified, is used to separate
64 /// instructions from each other when on the same line. This is used to
65 /// measure inline asm instructions.
66 char SeparatorChar; // Defaults to ';'
68 /// CommentColumn - This indicates the comment num (zero-based) at
69 /// which asm comments should be printed.
70 unsigned CommentColumn; // Defaults to 60
72 /// CommentString - This indicates the comment character used by the
74 const char *CommentString; // Defaults to "#"
76 /// GlobalPrefix - If this is set to a non-empty string, it is prepended
77 /// onto all global symbols. This is often used for "_" or ".".
78 const char *GlobalPrefix; // Defaults to ""
80 /// PrivateGlobalPrefix - This prefix is used for globals like constant
81 /// pool entries that are completely private to the .s file and should not
82 /// have names in the .o file. This is often "." or "L".
83 const char *PrivateGlobalPrefix; // Defaults to "."
85 /// LinkerPrivateGlobalPrefix - This prefix is used for symbols that should
86 /// be passed through the assembler but be removed by the linker. This
87 /// is "l" on Darwin, currently used for some ObjC metadata.
88 const char *LinkerPrivateGlobalPrefix; // Defaults to ""
90 /// JumpTableSpecialLabelPrefix - If not null, a extra (dead) label is
91 /// emitted before jump tables with the specified prefix.
92 const char *JumpTableSpecialLabelPrefix; // Default to null.
94 /// GlobalVarAddrPrefix/Suffix - If these are nonempty, these strings
95 /// will enclose any GlobalVariable (that isn't a function)
97 const char *GlobalVarAddrPrefix; // Defaults to ""
98 const char *GlobalVarAddrSuffix; // Defaults to ""
100 /// FunctionAddrPrefix/Suffix - If these are nonempty, these strings
101 /// will enclose any GlobalVariable that points to a function.
103 const char *FunctionAddrPrefix; // Defaults to ""
104 const char *FunctionAddrSuffix; // Defaults to ""
106 /// PersonalityPrefix/Suffix - If these are nonempty, these strings will
107 /// enclose any personality function in the common frame section.
109 const char *PersonalityPrefix; // Defaults to ""
110 const char *PersonalitySuffix; // Defaults to ""
112 /// NeedsIndirectEncoding - If set, we need to set the indirect encoding bit
115 bool NeedsIndirectEncoding; // Defaults to false
117 /// InlineAsmStart/End - If these are nonempty, they contain a directive to
118 /// emit before and after an inline assembly statement.
119 const char *InlineAsmStart; // Defaults to "#APP\n"
120 const char *InlineAsmEnd; // Defaults to "#NO_APP\n"
122 /// AssemblerDialect - Which dialect of an assembler variant to use.
123 unsigned AssemblerDialect; // Defaults to 0
125 /// AllowQuotesInName - This is true if the assembler allows for complex
126 /// symbol names to be surrounded in quotes. This defaults to false.
127 bool AllowQuotesInName;
129 //===--- Data Emission Directives -------------------------------------===//
131 /// ZeroDirective - this should be set to the directive used to get some
132 /// number of zero bytes emitted to the current section. Common cases are
133 /// "\t.zero\t" and "\t.space\t". If this is set to null, the
134 /// Data*bitsDirective's will be used to emit zero bytes.
135 const char *ZeroDirective; // Defaults to "\t.zero\t"
136 const char *ZeroDirectiveSuffix; // Defaults to ""
138 /// AsciiDirective - This directive allows emission of an ascii string with
139 /// the standard C escape characters embedded into it.
140 const char *AsciiDirective; // Defaults to "\t.ascii\t"
142 /// AscizDirective - If not null, this allows for special handling of
143 /// zero terminated strings on this target. This is commonly supported as
144 /// ".asciz". If a target doesn't support this, it can be set to null.
145 const char *AscizDirective; // Defaults to "\t.asciz\t"
147 /// DataDirectives - These directives are used to output some unit of
148 /// integer data to the current section. If a data directive is set to
149 /// null, smaller data directives will be used to emit the large sizes.
150 const char *Data8bitsDirective; // Defaults to "\t.byte\t"
151 const char *Data16bitsDirective; // Defaults to "\t.short\t"
152 const char *Data32bitsDirective; // Defaults to "\t.long\t"
153 const char *Data64bitsDirective; // Defaults to "\t.quad\t"
155 /// getDataASDirective - Return the directive that should be used to emit
156 /// data of the specified size to the specified numeric address space.
157 virtual const char *getDataASDirective(unsigned Size, unsigned AS) const {
158 assert(AS != 0 && "Don't know the directives for default addr space");
162 /// SunStyleELFSectionSwitchSyntax - This is true if this target uses "Sun
163 /// Style" syntax for section switching ("#alloc,#write" etc) instead of the
164 /// normal ELF syntax (,"a,w") in .section directives.
165 bool SunStyleELFSectionSwitchSyntax; // Defaults to false.
167 /// UsesELFSectionDirectiveForBSS - This is true if this target uses ELF
168 /// '.section' directive before the '.bss' one. It's used for PPC/Linux
169 /// which doesn't support the '.bss' directive only.
170 bool UsesELFSectionDirectiveForBSS; // Defaults to false.
172 //===--- Alignment Information ----------------------------------------===//
174 /// AlignDirective - The directive used to emit round up to an alignment
177 const char *AlignDirective; // Defaults to "\t.align\t"
179 /// AlignmentIsInBytes - If this is true (the default) then the asmprinter
180 /// emits ".align N" directives, where N is the number of bytes to align to.
181 /// Otherwise, it emits ".align log2(N)", e.g. 3 to align to an 8 byte
183 bool AlignmentIsInBytes; // Defaults to true
185 /// TextAlignFillValue - If non-zero, this is used to fill the executable
186 /// space created as the result of a alignment directive.
187 unsigned TextAlignFillValue;
189 //===--- Section Switching Directives ---------------------------------===//
191 /// JumpTableDirective - if non-null, the directive to emit before jump
192 /// table entries. FIXME: REMOVE THIS.
193 const char *JumpTableDirective;
194 const char *PICJumpTableDirective;
197 //===--- Global Variable Emission Directives --------------------------===//
199 /// GlobalDirective - This is the directive used to declare a global entity.
201 const char *GlobalDirective; // Defaults to NULL.
203 /// ExternDirective - This is the directive used to declare external
206 const char *ExternDirective; // Defaults to NULL.
208 /// SetDirective - This is the name of a directive that can be used to tell
209 /// the assembler to set the value of a variable to some expression.
210 const char *SetDirective; // Defaults to null.
212 /// LCOMMDirective - This is the name of a directive (if supported) that can
213 /// be used to efficiently declare a local (internal) block of zero
214 /// initialized data in the .bss/.data section. The syntax expected is:
215 /// @verbatim <LCOMMDirective> SYMBOLNAME LENGTHINBYTES, ALIGNMENT
217 const char *LCOMMDirective; // Defaults to null.
219 const char *COMMDirective; // Defaults to "\t.comm\t".
221 /// COMMDirectiveTakesAlignment - True if COMMDirective take a third
222 /// argument that specifies the alignment of the declaration.
223 bool COMMDirectiveTakesAlignment; // Defaults to true.
225 /// HasDotTypeDotSizeDirective - True if the target has .type and .size
226 /// directives, this is true for most ELF targets.
227 bool HasDotTypeDotSizeDirective; // Defaults to true.
229 /// HasSingleParameterDotFile - True if the target has a single parameter
230 /// .file directive, this is true for ELF targets.
231 bool HasSingleParameterDotFile; // Defaults to true.
233 /// UsedDirective - This directive, if non-null, is used to declare a global
234 /// as being used somehow that the assembler can't see. This prevents dead
235 /// code elimination on some targets.
236 const char *UsedDirective; // Defaults to null.
238 /// WeakRefDirective - This directive, if non-null, is used to declare a
239 /// global as being a weak undefined symbol.
240 const char *WeakRefDirective; // Defaults to null.
242 /// WeakDefDirective - This directive, if non-null, is used to declare a
243 /// global as being a weak defined symbol.
244 const char *WeakDefDirective; // Defaults to null.
246 /// HiddenDirective - This directive, if non-null, is used to declare a
247 /// global or function as having hidden visibility.
248 const char *HiddenDirective; // Defaults to "\t.hidden\t".
250 /// ProtectedDirective - This directive, if non-null, is used to declare a
251 /// global or function as having protected visibility.
252 const char *ProtectedDirective; // Defaults to "\t.protected\t".
254 //===--- Dwarf Emission Directives -----------------------------------===//
256 /// AbsoluteDebugSectionOffsets - True if we should emit abolute section
257 /// offsets for debug information.
258 bool AbsoluteDebugSectionOffsets; // Defaults to false.
260 /// AbsoluteEHSectionOffsets - True if we should emit abolute section
261 /// offsets for EH information. Defaults to false.
262 bool AbsoluteEHSectionOffsets;
264 /// HasLEB128 - True if target asm supports leb128 directives.
265 bool HasLEB128; // Defaults to false.
267 /// hasDotLocAndDotFile - True if target asm supports .loc and .file
268 /// directives for emitting debugging information.
269 bool HasDotLocAndDotFile; // Defaults to false.
271 /// SupportsDebugInformation - True if target supports emission of debugging
273 bool SupportsDebugInformation; // Defaults to false.
275 /// SupportsExceptionHandling - True if target supports exception handling.
276 ExceptionHandling::ExceptionsType ExceptionsType; // Defaults to None
278 /// RequiresFrameSection - true if the Dwarf2 output needs a frame section
279 bool DwarfRequiresFrameSection; // Defaults to true.
281 /// DwarfUsesInlineInfoSection - True if DwarfDebugInlineSection is used to
282 /// encode inline subroutine information.
283 bool DwarfUsesInlineInfoSection; // Defaults to false.
285 /// Is_EHSymbolPrivate - If set, the "_foo.eh" is made private so that it
286 /// doesn't show up in the symbol table of the object file.
287 bool Is_EHSymbolPrivate; // Defaults to true.
289 /// ForceEncodingOfFDETo32Bits - If set, the encoding of some of the FDE
290 /// data is forced to 32-bit.
291 bool ForceEncodingOfFDETo32Bits; // Defaults to true.
293 /// GlobalEHDirective - This is the directive used to make exception frame
294 /// tables globally visible.
295 const char *GlobalEHDirective; // Defaults to NULL.
297 /// SupportsWeakEmptyEHFrame - True if target assembler and linker will
298 /// handle a weak_definition of constant 0 for an omitted EH frame.
299 bool SupportsWeakOmittedEHFrame; // Defaults to true.
301 /// DwarfSectionOffsetDirective - Special section offset directive.
302 const char* DwarfSectionOffsetDirective; // Defaults to NULL
304 //===--- CBE Asm Translation Table -----------------------------------===//
306 const char *const *AsmTransCBE; // Defaults to empty
309 explicit MCAsmInfo();
310 virtual ~MCAsmInfo();
312 /// getSLEB128Size - Compute the number of bytes required for a signed
314 static unsigned getSLEB128Size(int Value);
316 /// getULEB128Size - Compute the number of bytes required for an unsigned
318 static unsigned getULEB128Size(unsigned Value);
320 // Data directive accessors.
322 const char *getData8bitsDirective(unsigned AS = 0) const {
323 return AS == 0 ? Data8bitsDirective : getDataASDirective(8, AS);
325 const char *getData16bitsDirective(unsigned AS = 0) const {
326 return AS == 0 ? Data16bitsDirective : getDataASDirective(16, AS);
328 const char *getData32bitsDirective(unsigned AS = 0) const {
329 return AS == 0 ? Data32bitsDirective : getDataASDirective(32, AS);
331 const char *getData64bitsDirective(unsigned AS = 0) const {
332 return AS == 0 ? Data64bitsDirective : getDataASDirective(64, AS);
336 bool usesSunStyleELFSectionSwitchSyntax() const {
337 return SunStyleELFSectionSwitchSyntax;
340 bool usesELFSectionDirectiveForBSS() const {
341 return UsesELFSectionDirectiveForBSS;
346 const char *getZeroFillDirective() const {
347 return ZeroFillDirective;
349 const char *getNonexecutableStackDirective() const {
350 return NonexecutableStackDirective;
352 bool needsSet() const {
355 unsigned getMaxInstLength() const {
356 return MaxInstLength;
358 const char *getPCSymbol() const {
361 char getSeparatorChar() const {
362 return SeparatorChar;
364 unsigned getCommentColumn() const {
365 return CommentColumn;
367 const char *getCommentString() const {
368 return CommentString;
370 const char *getGlobalPrefix() const {
373 const char *getPrivateGlobalPrefix() const {
374 return PrivateGlobalPrefix;
376 const char *getLinkerPrivateGlobalPrefix() const {
377 return LinkerPrivateGlobalPrefix;
379 const char *getJumpTableSpecialLabelPrefix() const {
380 return JumpTableSpecialLabelPrefix;
382 const char *getGlobalVarAddrPrefix() const {
383 return GlobalVarAddrPrefix;
385 const char *getGlobalVarAddrSuffix() const {
386 return GlobalVarAddrSuffix;
388 const char *getFunctionAddrPrefix() const {
389 return FunctionAddrPrefix;
391 const char *getFunctionAddrSuffix() const {
392 return FunctionAddrSuffix;
394 const char *getPersonalityPrefix() const {
395 return PersonalityPrefix;
397 const char *getPersonalitySuffix() const {
398 return PersonalitySuffix;
400 bool getNeedsIndirectEncoding() const {
401 return NeedsIndirectEncoding;
403 const char *getInlineAsmStart() const {
404 return InlineAsmStart;
406 const char *getInlineAsmEnd() const {
409 unsigned getAssemblerDialect() const {
410 return AssemblerDialect;
412 bool doesAllowQuotesInName() const {
413 return AllowQuotesInName;
415 const char *getZeroDirective() const {
416 return ZeroDirective;
418 const char *getZeroDirectiveSuffix() const {
419 return ZeroDirectiveSuffix;
421 const char *getAsciiDirective() const {
422 return AsciiDirective;
424 const char *getAscizDirective() const {
425 return AscizDirective;
427 const char *getJumpTableDirective(bool isPIC) const {
428 return isPIC ? PICJumpTableDirective : JumpTableDirective;
430 const char *getAlignDirective() const {
431 return AlignDirective;
433 bool getAlignmentIsInBytes() const {
434 return AlignmentIsInBytes;
436 unsigned getTextAlignFillValue() const {
437 return TextAlignFillValue;
439 const char *getGlobalDirective() const {
440 return GlobalDirective;
442 const char *getExternDirective() const {
443 return ExternDirective;
445 const char *getSetDirective() const {
448 const char *getLCOMMDirective() const {
449 return LCOMMDirective;
451 const char *getCOMMDirective() const {
452 return COMMDirective;
454 bool getCOMMDirectiveTakesAlignment() const {
455 return COMMDirectiveTakesAlignment;
457 bool hasDotTypeDotSizeDirective() const {
458 return HasDotTypeDotSizeDirective;
460 bool hasSingleParameterDotFile() const {
461 return HasSingleParameterDotFile;
463 const char *getUsedDirective() const {
464 return UsedDirective;
466 const char *getWeakRefDirective() const {
467 return WeakRefDirective;
469 const char *getWeakDefDirective() const {
470 return WeakDefDirective;
472 const char *getHiddenDirective() const {
473 return HiddenDirective;
475 const char *getProtectedDirective() const {
476 return ProtectedDirective;
478 bool isAbsoluteDebugSectionOffsets() const {
479 return AbsoluteDebugSectionOffsets;
481 bool isAbsoluteEHSectionOffsets() const {
482 return AbsoluteEHSectionOffsets;
484 bool hasLEB128() const {
487 bool hasDotLocAndDotFile() const {
488 return HasDotLocAndDotFile;
490 bool doesSupportDebugInformation() const {
491 return SupportsDebugInformation;
493 bool doesSupportExceptionHandling() const {
494 return ExceptionsType != ExceptionHandling::None;
496 ExceptionHandling::ExceptionsType getExceptionHandlingType() const {
497 return ExceptionsType;
499 bool doesDwarfRequireFrameSection() const {
500 return DwarfRequiresFrameSection;
502 bool doesDwarfUsesInlineInfoSection() const {
503 return DwarfUsesInlineInfoSection;
505 bool is_EHSymbolPrivate() const {
506 return Is_EHSymbolPrivate;
508 bool forceEncodingOfFDETo32Bits() const {
509 return ForceEncodingOfFDETo32Bits;
511 const char *getGlobalEHDirective() const {
512 return GlobalEHDirective;
514 bool getSupportsWeakOmittedEHFrame() const {
515 return SupportsWeakOmittedEHFrame;
517 const char *getDwarfSectionOffsetDirective() const {
518 return DwarfSectionOffsetDirective;
520 const char *const *getAsmCBE() const {