1 //===-- llvm/Target/TargetAsmInfo.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"
24 template <typename T> class SmallVectorImpl;
26 /// TargetAsmInfo - This class is intended to be used as a base class for asm
27 /// properties and features specific to the target.
28 namespace ExceptionHandling { enum ExceptionsType { None, Dwarf, SjLj }; }
32 //===------------------------------------------------------------------===//
33 // Properties to be set by the target writer, used to configure asm printer.
36 /// ZeroFillDirective - Directive for emitting a global to the ZeroFill
37 /// section on this target. Null if this target doesn't support zerofill.
38 const char *ZeroFillDirective; // Default is null.
40 /// NonexecutableStackDirective - Directive for declaring to the
41 /// linker and beyond that the emitted code does not require stack
42 /// memory to be executable.
43 const char *NonexecutableStackDirective; // Default is null.
45 /// NeedsSet - True if target asm treats expressions in data directives
46 /// as linktime-relocatable. For assembly-time computation, we need to
50 /// is computed at assembly time, while
52 /// is relocated if the relative locations of x and y change at linktime.
53 /// We want both these things in different places.
54 bool NeedsSet; // Defaults to false.
56 /// MaxInstLength - This is the maximum possible length of an instruction,
57 /// which is needed to compute the size of an inline asm.
58 unsigned MaxInstLength; // Defaults to 4.
60 /// PCSymbol - The symbol used to represent the current PC. Used in PC
61 /// relative expressions.
62 const char *PCSymbol; // Defaults to "$".
64 /// SeparatorChar - This character, if specified, is used to separate
65 /// instructions from each other when on the same line. This is used to
66 /// measure inline asm instructions.
67 char SeparatorChar; // Defaults to ';'
69 /// CommentColumn - This indicates the comment num (zero-based) at
70 /// which asm comments should be printed.
71 unsigned CommentColumn; // Defaults to 60
73 /// CommentString - This indicates the comment character used by the
75 const char *CommentString; // Defaults to "#"
77 /// GlobalPrefix - If this is set to a non-empty string, it is prepended
78 /// onto all global symbols. This is often used for "_" or ".".
79 const char *GlobalPrefix; // Defaults to ""
81 /// PrivateGlobalPrefix - This prefix is used for globals like constant
82 /// pool entries that are completely private to the .s file and should not
83 /// have names in the .o file. This is often "." or "L".
84 const char *PrivateGlobalPrefix; // Defaults to "."
86 /// LinkerPrivateGlobalPrefix - This prefix is used for symbols that should
87 /// be passed through the assembler but be removed by the linker. This
88 /// is "l" on Darwin, currently used for some ObjC metadata.
89 const char *LinkerPrivateGlobalPrefix; // Defaults to ""
91 /// JumpTableSpecialLabelPrefix - If not null, a extra (dead) label is
92 /// emitted before jump tables with the specified prefix.
93 const char *JumpTableSpecialLabelPrefix; // Default to null.
95 /// GlobalVarAddrPrefix/Suffix - If these are nonempty, these strings
96 /// will enclose any GlobalVariable (that isn't a function)
98 const char *GlobalVarAddrPrefix; // Defaults to ""
99 const char *GlobalVarAddrSuffix; // Defaults to ""
101 /// FunctionAddrPrefix/Suffix - If these are nonempty, these strings
102 /// will enclose any GlobalVariable that points to a function.
104 const char *FunctionAddrPrefix; // Defaults to ""
105 const char *FunctionAddrSuffix; // Defaults to ""
107 /// PersonalityPrefix/Suffix - If these are nonempty, these strings will
108 /// enclose any personality function in the common frame section.
110 const char *PersonalityPrefix; // Defaults to ""
111 const char *PersonalitySuffix; // Defaults to ""
113 /// NeedsIndirectEncoding - If set, we need to set the indirect encoding bit
116 bool NeedsIndirectEncoding; // Defaults to false
118 /// InlineAsmStart/End - If these are nonempty, they contain a directive to
119 /// emit before and after an inline assembly statement.
120 const char *InlineAsmStart; // Defaults to "#APP\n"
121 const char *InlineAsmEnd; // Defaults to "#NO_APP\n"
123 /// AssemblerDialect - Which dialect of an assembler variant to use.
124 unsigned AssemblerDialect; // Defaults to 0
126 /// AllowQuotesInName - This is true if the assembler allows for complex
127 /// symbol names to be surrounded in quotes. This defaults to false.
128 bool AllowQuotesInName;
130 //===--- Data Emission Directives -------------------------------------===//
132 /// ZeroDirective - this should be set to the directive used to get some
133 /// number of zero bytes emitted to the current section. Common cases are
134 /// "\t.zero\t" and "\t.space\t". If this is set to null, the
135 /// Data*bitsDirective's will be used to emit zero bytes.
136 const char *ZeroDirective; // Defaults to "\t.zero\t"
137 const char *ZeroDirectiveSuffix; // Defaults to ""
139 /// AsciiDirective - This directive allows emission of an ascii string with
140 /// the standard C escape characters embedded into it.
141 const char *AsciiDirective; // Defaults to "\t.ascii\t"
143 /// AscizDirective - If not null, this allows for special handling of
144 /// zero terminated strings on this target. This is commonly supported as
145 /// ".asciz". If a target doesn't support this, it can be set to null.
146 const char *AscizDirective; // Defaults to "\t.asciz\t"
148 /// DataDirectives - These directives are used to output some unit of
149 /// integer data to the current section. If a data directive is set to
150 /// null, smaller data directives will be used to emit the large sizes.
151 const char *Data8bitsDirective; // Defaults to "\t.byte\t"
152 const char *Data16bitsDirective; // Defaults to "\t.short\t"
153 const char *Data32bitsDirective; // Defaults to "\t.long\t"
154 const char *Data64bitsDirective; // Defaults to "\t.quad\t"
156 /// getDataASDirective - Return the directive that should be used to emit
157 /// data of the specified size to the specified numeric address space.
158 virtual const char *getDataASDirective(unsigned Size, unsigned AS) const {
159 assert(AS != 0 && "Don't know the directives for default addr space");
163 /// SunStyleELFSectionSwitchSyntax - This is true if this target uses "Sun
164 /// Style" syntax for section switching ("#alloc,#write" etc) instead of the
165 /// normal ELF syntax (,"a,w") in .section directives.
166 bool SunStyleELFSectionSwitchSyntax; // Defaults to false.
168 /// UsesELFSectionDirectiveForBSS - This is true if this target uses ELF
169 /// '.section' directive before the '.bss' one. It's used for PPC/Linux
170 /// which doesn't support the '.bss' directive only.
171 bool UsesELFSectionDirectiveForBSS; // Defaults to false.
173 //===--- Alignment Information ----------------------------------------===//
175 /// AlignDirective - The directive used to emit round up to an alignment
178 const char *AlignDirective; // Defaults to "\t.align\t"
180 /// AlignmentIsInBytes - If this is true (the default) then the asmprinter
181 /// emits ".align N" directives, where N is the number of bytes to align to.
182 /// Otherwise, it emits ".align log2(N)", e.g. 3 to align to an 8 byte
184 bool AlignmentIsInBytes; // Defaults to true
186 /// TextAlignFillValue - If non-zero, this is used to fill the executable
187 /// space created as the result of a alignment directive.
188 unsigned TextAlignFillValue;
190 //===--- Section Switching Directives ---------------------------------===//
192 /// JumpTableDirective - if non-null, the directive to emit before jump
193 /// table entries. FIXME: REMOVE THIS.
194 const char *JumpTableDirective;
195 const char *PICJumpTableDirective;
198 //===--- Global Variable Emission Directives --------------------------===//
200 /// GlobalDirective - This is the directive used to declare a global entity.
202 const char *GlobalDirective; // Defaults to NULL.
204 /// ExternDirective - This is the directive used to declare external
207 const char *ExternDirective; // Defaults to NULL.
209 /// SetDirective - This is the name of a directive that can be used to tell
210 /// the assembler to set the value of a variable to some expression.
211 const char *SetDirective; // Defaults to null.
213 /// LCOMMDirective - This is the name of a directive (if supported) that can
214 /// be used to efficiently declare a local (internal) block of zero
215 /// initialized data in the .bss/.data section. The syntax expected is:
216 /// @verbatim <LCOMMDirective> SYMBOLNAME LENGTHINBYTES, ALIGNMENT
218 const char *LCOMMDirective; // Defaults to null.
220 const char *COMMDirective; // Defaults to "\t.comm\t".
222 /// COMMDirectiveTakesAlignment - True if COMMDirective take a third
223 /// argument that specifies the alignment of the declaration.
224 bool COMMDirectiveTakesAlignment; // Defaults to true.
226 /// HasDotTypeDotSizeDirective - True if the target has .type and .size
227 /// directives, this is true for most ELF targets.
228 bool HasDotTypeDotSizeDirective; // Defaults to true.
230 /// HasSingleParameterDotFile - True if the target has a single parameter
231 /// .file directive, this is true for ELF targets.
232 bool HasSingleParameterDotFile; // Defaults to true.
234 /// UsedDirective - This directive, if non-null, is used to declare a global
235 /// as being used somehow that the assembler can't see. This prevents dead
236 /// code elimination on some targets.
237 const char *UsedDirective; // Defaults to null.
239 /// WeakRefDirective - This directive, if non-null, is used to declare a
240 /// global as being a weak undefined symbol.
241 const char *WeakRefDirective; // Defaults to null.
243 /// WeakDefDirective - This directive, if non-null, is used to declare a
244 /// global as being a weak defined symbol.
245 const char *WeakDefDirective; // Defaults to null.
247 /// HiddenDirective - This directive, if non-null, is used to declare a
248 /// global or function as having hidden visibility.
249 const char *HiddenDirective; // Defaults to "\t.hidden\t".
251 /// ProtectedDirective - This directive, if non-null, is used to declare a
252 /// global or function as having protected visibility.
253 const char *ProtectedDirective; // Defaults to "\t.protected\t".
255 //===--- Dwarf Emission Directives -----------------------------------===//
257 /// AbsoluteDebugSectionOffsets - True if we should emit abolute section
258 /// offsets for debug information. Defaults to false.
259 bool AbsoluteDebugSectionOffsets;
261 /// AbsoluteEHSectionOffsets - True if we should emit abolute section
262 /// offsets for EH information. Defaults to false.
263 bool AbsoluteEHSectionOffsets;
265 /// HasLEB128 - True if target asm supports leb128 directives.
267 bool HasLEB128; // Defaults to false.
269 /// hasDotLocAndDotFile - True if target asm supports .loc and .file
270 /// directives for emitting debugging information.
272 bool HasDotLocAndDotFile; // Defaults to false.
274 /// SupportsDebugInformation - True if target supports emission of debugging
276 bool SupportsDebugInformation;
278 /// SupportsExceptionHandling - True if target supports
279 /// exception handling.
282 ExceptionHandling::ExceptionsType ExceptionsType;
284 /// RequiresFrameSection - true if the Dwarf2 output needs a frame section
286 bool DwarfRequiresFrameSection; // Defaults to true.
288 /// DwarfUsesInlineInfoSection - True if DwarfDebugInlineSection is used to
289 /// encode inline subroutine information.
290 bool DwarfUsesInlineInfoSection; // Defaults to false.
292 /// Is_EHSymbolPrivate - If set, the "_foo.eh" is made private so that it
293 /// doesn't show up in the symbol table of the object file.
294 bool Is_EHSymbolPrivate; // Defaults to true.
296 /// GlobalEHDirective - This is the directive used to make exception frame
297 /// tables globally visible.
299 const char *GlobalEHDirective; // Defaults to NULL.
301 /// SupportsWeakEmptyEHFrame - True if target assembler and linker will
302 /// handle a weak_definition of constant 0 for an omitted EH frame.
303 bool SupportsWeakOmittedEHFrame; // Defaults to true.
305 /// DwarfSectionOffsetDirective - Special section offset directive.
306 const char* DwarfSectionOffsetDirective; // Defaults to NULL
308 //===--- CBE Asm Translation Table -----------------------------------===//
310 const char *const *AsmTransCBE; // Defaults to empty
313 explicit TargetAsmInfo();
314 virtual ~TargetAsmInfo();
316 /// getSLEB128Size - Compute the number of bytes required for a signed
318 static unsigned getSLEB128Size(int Value);
320 /// getULEB128Size - Compute the number of bytes required for an unsigned
322 static unsigned getULEB128Size(unsigned Value);
324 // Data directive accessors.
326 const char *getData8bitsDirective(unsigned AS = 0) const {
327 return AS == 0 ? Data8bitsDirective : getDataASDirective(8, AS);
329 const char *getData16bitsDirective(unsigned AS = 0) const {
330 return AS == 0 ? Data16bitsDirective : getDataASDirective(16, AS);
332 const char *getData32bitsDirective(unsigned AS = 0) const {
333 return AS == 0 ? Data32bitsDirective : getDataASDirective(32, AS);
335 const char *getData64bitsDirective(unsigned AS = 0) const {
336 return AS == 0 ? Data64bitsDirective : getDataASDirective(64, AS);
340 bool usesSunStyleELFSectionSwitchSyntax() const {
341 return SunStyleELFSectionSwitchSyntax;
344 bool usesELFSectionDirectiveForBSS() const {
345 return UsesELFSectionDirectiveForBSS;
350 const char *getZeroFillDirective() const {
351 return ZeroFillDirective;
353 const char *getNonexecutableStackDirective() const {
354 return NonexecutableStackDirective;
356 bool needsSet() const {
359 unsigned getMaxInstLength() const {
360 return MaxInstLength;
362 const char *getPCSymbol() const {
365 char getSeparatorChar() const {
366 return SeparatorChar;
368 unsigned getCommentColumn() const {
369 return CommentColumn;
371 const char *getCommentString() const {
372 return CommentString;
374 const char *getGlobalPrefix() const {
377 const char *getPrivateGlobalPrefix() const {
378 return PrivateGlobalPrefix;
380 const char *getLinkerPrivateGlobalPrefix() const {
381 return LinkerPrivateGlobalPrefix;
383 const char *getJumpTableSpecialLabelPrefix() const {
384 return JumpTableSpecialLabelPrefix;
386 const char *getGlobalVarAddrPrefix() const {
387 return GlobalVarAddrPrefix;
389 const char *getGlobalVarAddrSuffix() const {
390 return GlobalVarAddrSuffix;
392 const char *getFunctionAddrPrefix() const {
393 return FunctionAddrPrefix;
395 const char *getFunctionAddrSuffix() const {
396 return FunctionAddrSuffix;
398 const char *getPersonalityPrefix() const {
399 return PersonalityPrefix;
401 const char *getPersonalitySuffix() const {
402 return PersonalitySuffix;
404 bool getNeedsIndirectEncoding() const {
405 return NeedsIndirectEncoding;
407 const char *getInlineAsmStart() const {
408 return InlineAsmStart;
410 const char *getInlineAsmEnd() const {
413 unsigned getAssemblerDialect() const {
414 return AssemblerDialect;
416 bool doesAllowQuotesInName() const {
417 return AllowQuotesInName;
419 const char *getZeroDirective() const {
420 return ZeroDirective;
422 const char *getZeroDirectiveSuffix() const {
423 return ZeroDirectiveSuffix;
425 const char *getAsciiDirective() const {
426 return AsciiDirective;
428 const char *getAscizDirective() const {
429 return AscizDirective;
431 const char *getJumpTableDirective(bool isPIC) const {
432 return isPIC ? PICJumpTableDirective : JumpTableDirective;
434 const char *getAlignDirective() const {
435 return AlignDirective;
437 bool getAlignmentIsInBytes() const {
438 return AlignmentIsInBytes;
440 unsigned getTextAlignFillValue() const {
441 return TextAlignFillValue;
443 const char *getGlobalDirective() const {
444 return GlobalDirective;
446 const char *getExternDirective() const {
447 return ExternDirective;
449 const char *getSetDirective() const {
452 const char *getLCOMMDirective() const {
453 return LCOMMDirective;
455 const char *getCOMMDirective() const {
456 return COMMDirective;
458 bool getCOMMDirectiveTakesAlignment() const {
459 return COMMDirectiveTakesAlignment;
461 bool hasDotTypeDotSizeDirective() const {
462 return HasDotTypeDotSizeDirective;
464 bool hasSingleParameterDotFile() const {
465 return HasSingleParameterDotFile;
467 const char *getUsedDirective() const {
468 return UsedDirective;
470 const char *getWeakRefDirective() const {
471 return WeakRefDirective;
473 const char *getWeakDefDirective() const {
474 return WeakDefDirective;
476 const char *getHiddenDirective() const {
477 return HiddenDirective;
479 const char *getProtectedDirective() const {
480 return ProtectedDirective;
482 bool isAbsoluteDebugSectionOffsets() const {
483 return AbsoluteDebugSectionOffsets;
485 bool isAbsoluteEHSectionOffsets() const {
486 return AbsoluteEHSectionOffsets;
488 bool hasLEB128() const {
491 bool hasDotLocAndDotFile() const {
492 return HasDotLocAndDotFile;
494 bool doesSupportDebugInformation() const {
495 return SupportsDebugInformation;
497 bool doesSupportExceptionHandling() const {
498 return ExceptionsType != ExceptionHandling::None;
500 ExceptionHandling::ExceptionsType getExceptionHandlingType() const {
501 return ExceptionsType;
503 bool doesDwarfRequireFrameSection() const {
504 return DwarfRequiresFrameSection;
506 bool doesDwarfUsesInlineInfoSection() const {
507 return DwarfUsesInlineInfoSection;
509 bool is_EHSymbolPrivate() const {
510 return Is_EHSymbolPrivate;
512 const char *getGlobalEHDirective() const {
513 return GlobalEHDirective;
515 bool getSupportsWeakOmittedEHFrame() const {
516 return SupportsWeakOmittedEHFrame;
518 const char *getDwarfSectionOffsetDirective() const {
519 return DwarfSectionOffsetDirective;
521 const char *const *getAsmCBE() const {