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.
30 //===------------------------------------------------------------------===//
31 // Properties to be set by the target writer, used to configure asm printer.
34 /// ZeroFillDirective - Directive for emitting a global to the ZeroFill
35 /// section on this target. Null if this target doesn't support zerofill.
36 const char *ZeroFillDirective; // Default is null.
38 /// NonexecutableStackDirective - Directive for declaring to the
39 /// linker and beyond that the emitted code does not require stack
40 /// memory to be executable.
41 const char *NonexecutableStackDirective; // Default is null.
43 /// NeedsSet - True if target asm treats expressions in data directives
44 /// as linktime-relocatable. For assembly-time computation, we need to
48 /// is computed at assembly time, while
50 /// is relocated if the relative locations of x and y change at linktime.
51 /// We want both these things in different places.
52 bool NeedsSet; // Defaults to false.
54 /// MaxInstLength - This is the maximum possible length of an instruction,
55 /// which is needed to compute the size of an inline asm.
56 unsigned MaxInstLength; // Defaults to 4.
58 /// PCSymbol - The symbol used to represent the current PC. Used in PC
59 /// relative expressions.
60 const char *PCSymbol; // Defaults to "$".
62 /// SeparatorChar - This character, if specified, is used to separate
63 /// instructions from each other when on the same line. This is used to
64 /// measure inline asm instructions.
65 char SeparatorChar; // Defaults to ';'
67 /// CommentColumn - This indicates the comment num (zero-based) at
68 /// which asm comments should be printed.
69 unsigned CommentColumn; // Defaults to 60
71 /// CommentString - This indicates the comment character used by the
73 const char *CommentString; // Defaults to "#"
75 /// GlobalPrefix - If this is set to a non-empty string, it is prepended
76 /// onto all global symbols. This is often used for "_" or ".".
77 const char *GlobalPrefix; // Defaults to ""
79 /// PrivateGlobalPrefix - This prefix is used for globals like constant
80 /// pool entries that are completely private to the .s file and should not
81 /// have names in the .o file. This is often "." or "L".
82 const char *PrivateGlobalPrefix; // Defaults to "."
84 /// LinkerPrivateGlobalPrefix - This prefix is used for symbols that should
85 /// be passed through the assembler but be removed by the linker. This
86 /// is "l" on Darwin, currently used for some ObjC metadata.
87 const char *LinkerPrivateGlobalPrefix; // Defaults to ""
89 /// JumpTableSpecialLabelPrefix - If not null, a extra (dead) label is
90 /// emitted before jump tables with the specified prefix.
91 const char *JumpTableSpecialLabelPrefix; // Default to null.
93 /// GlobalVarAddrPrefix/Suffix - If these are nonempty, these strings
94 /// will enclose any GlobalVariable (that isn't a function)
96 const char *GlobalVarAddrPrefix; // Defaults to ""
97 const char *GlobalVarAddrSuffix; // Defaults to ""
99 /// FunctionAddrPrefix/Suffix - If these are nonempty, these strings
100 /// will enclose any GlobalVariable that points to a function.
102 const char *FunctionAddrPrefix; // Defaults to ""
103 const char *FunctionAddrSuffix; // Defaults to ""
105 /// PersonalityPrefix/Suffix - If these are nonempty, these strings will
106 /// enclose any personality function in the common frame section.
108 const char *PersonalityPrefix; // Defaults to ""
109 const char *PersonalitySuffix; // Defaults to ""
111 /// NeedsIndirectEncoding - If set, we need to set the indirect encoding bit
114 bool NeedsIndirectEncoding; // Defaults to false
116 /// InlineAsmStart/End - If these are nonempty, they contain a directive to
117 /// emit before and after an inline assembly statement.
118 const char *InlineAsmStart; // Defaults to "#APP\n"
119 const char *InlineAsmEnd; // Defaults to "#NO_APP\n"
121 /// AssemblerDialect - Which dialect of an assembler variant to use.
122 unsigned AssemblerDialect; // Defaults to 0
124 /// AllowQuotesInName - This is true if the assembler allows for complex
125 /// symbol names to be surrounded in quotes. This defaults to false.
126 bool AllowQuotesInName;
128 //===--- Data Emission Directives -------------------------------------===//
130 /// ZeroDirective - this should be set to the directive used to get some
131 /// number of zero bytes emitted to the current section. Common cases are
132 /// "\t.zero\t" and "\t.space\t". If this is set to null, the
133 /// Data*bitsDirective's will be used to emit zero bytes.
134 const char *ZeroDirective; // Defaults to "\t.zero\t"
135 const char *ZeroDirectiveSuffix; // Defaults to ""
137 /// AsciiDirective - This directive allows emission of an ascii string with
138 /// the standard C escape characters embedded into it.
139 const char *AsciiDirective; // Defaults to "\t.ascii\t"
141 /// AscizDirective - If not null, this allows for special handling of
142 /// zero terminated strings on this target. This is commonly supported as
143 /// ".asciz". If a target doesn't support this, it can be set to null.
144 const char *AscizDirective; // Defaults to "\t.asciz\t"
146 /// DataDirectives - These directives are used to output some unit of
147 /// integer data to the current section. If a data directive is set to
148 /// null, smaller data directives will be used to emit the large sizes.
149 const char *Data8bitsDirective; // Defaults to "\t.byte\t"
150 const char *Data16bitsDirective; // Defaults to "\t.short\t"
151 const char *Data32bitsDirective; // Defaults to "\t.long\t"
152 const char *Data64bitsDirective; // Defaults to "\t.quad\t"
154 /// getDataASDirective - Return the directive that should be used to emit
155 /// data of the specified size to the specified numeric address space.
156 virtual const char *getDataASDirective(unsigned Size, unsigned AS) const {
157 assert(AS != 0 && "Don't know the directives for default addr space");
161 //===--- Alignment Information ----------------------------------------===//
163 /// AlignDirective - The directive used to emit round up to an alignment
166 const char *AlignDirective; // Defaults to "\t.align\t"
168 /// AlignmentIsInBytes - If this is true (the default) then the asmprinter
169 /// emits ".align N" directives, where N is the number of bytes to align to.
170 /// Otherwise, it emits ".align log2(N)", e.g. 3 to align to an 8 byte
172 bool AlignmentIsInBytes; // Defaults to true
174 /// TextAlignFillValue - If non-zero, this is used to fill the executable
175 /// space created as the result of a alignment directive.
176 unsigned TextAlignFillValue;
178 //===--- Section Switching Directives ---------------------------------===//
180 /// SwitchToSectionDirective - This is the directive used when we want to
181 /// emit a global to an arbitrary section. The section name is emited after
183 const char *SwitchToSectionDirective; // Defaults to "\t.section\t"
185 /// JumpTableDirective - if non-null, the directive to emit before a jump
187 const char *JumpTableDirective;
189 //===--- Global Variable Emission Directives --------------------------===//
191 /// GlobalDirective - This is the directive used to declare a global entity.
193 const char *GlobalDirective; // Defaults to NULL.
195 /// ExternDirective - This is the directive used to declare external
198 const char *ExternDirective; // Defaults to NULL.
200 /// SetDirective - This is the name of a directive that can be used to tell
201 /// the assembler to set the value of a variable to some expression.
202 const char *SetDirective; // Defaults to null.
204 /// LCOMMDirective - This is the name of a directive (if supported) that can
205 /// be used to efficiently declare a local (internal) block of zero
206 /// initialized data in the .bss/.data section. The syntax expected is:
207 /// @verbatim <LCOMMDirective> SYMBOLNAME LENGTHINBYTES, ALIGNMENT
209 const char *LCOMMDirective; // Defaults to null.
211 const char *COMMDirective; // Defaults to "\t.comm\t".
213 /// COMMDirectiveTakesAlignment - True if COMMDirective take a third
214 /// argument that specifies the alignment of the declaration.
215 bool COMMDirectiveTakesAlignment; // Defaults to true.
217 /// HasDotTypeDotSizeDirective - True if the target has .type and .size
218 /// directives, this is true for most ELF targets.
219 bool HasDotTypeDotSizeDirective; // Defaults to true.
221 /// HasSingleParameterDotFile - True if the target has a single parameter
222 /// .file directive, this is true for ELF targets.
223 bool HasSingleParameterDotFile; // Defaults to true.
225 /// UsedDirective - This directive, if non-null, is used to declare a global
226 /// as being used somehow that the assembler can't see. This prevents dead
227 /// code elimination on some targets.
228 const char *UsedDirective; // Defaults to null.
230 /// WeakRefDirective - This directive, if non-null, is used to declare a
231 /// global as being a weak undefined symbol.
232 const char *WeakRefDirective; // Defaults to null.
234 /// WeakDefDirective - This directive, if non-null, is used to declare a
235 /// global as being a weak defined symbol.
236 const char *WeakDefDirective; // Defaults to null.
238 /// HiddenDirective - This directive, if non-null, is used to declare a
239 /// global or function as having hidden visibility.
240 const char *HiddenDirective; // Defaults to "\t.hidden\t".
242 /// ProtectedDirective - This directive, if non-null, is used to declare a
243 /// global or function as having protected visibility.
244 const char *ProtectedDirective; // Defaults to "\t.protected\t".
246 //===--- Dwarf Emission Directives -----------------------------------===//
248 /// AbsoluteDebugSectionOffsets - True if we should emit abolute section
249 /// offsets for debug information. Defaults to false.
250 bool AbsoluteDebugSectionOffsets;
252 /// AbsoluteEHSectionOffsets - True if we should emit abolute section
253 /// offsets for EH information. Defaults to false.
254 bool AbsoluteEHSectionOffsets;
256 /// 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.
263 bool HasDotLocAndDotFile; // Defaults to false.
265 /// SupportsDebugInformation - True if target supports emission of debugging
267 bool SupportsDebugInformation;
269 /// SupportsExceptionHandling - True if target supports
270 /// exception handling.
272 bool SupportsExceptionHandling; // Defaults to false.
274 /// 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.
289 const char *GlobalEHDirective; // Defaults to NULL.
291 /// SupportsWeakEmptyEHFrame - True if target assembler and linker will
292 /// handle a weak_definition of constant 0 for an omitted EH frame.
293 bool SupportsWeakOmittedEHFrame; // Defaults to true.
295 /// DwarfSectionOffsetDirective - Special section offset directive.
296 const char* DwarfSectionOffsetDirective; // Defaults to NULL
298 //===--- CBE Asm Translation Table -----------------------------------===//
300 const char *const *AsmTransCBE; // Defaults to empty
303 explicit TargetAsmInfo();
304 virtual ~TargetAsmInfo();
306 /// getSLEB128Size - Compute the number of bytes required for a signed
308 static unsigned getSLEB128Size(int Value);
310 /// getULEB128Size - Compute the number of bytes required for an unsigned
312 static unsigned getULEB128Size(unsigned Value);
314 // Data directive accessors.
316 const char *getData8bitsDirective(unsigned AS = 0) const {
317 return AS == 0 ? Data8bitsDirective : getDataASDirective(8, AS);
319 const char *getData16bitsDirective(unsigned AS = 0) const {
320 return AS == 0 ? Data16bitsDirective : getDataASDirective(16, AS);
322 const char *getData32bitsDirective(unsigned AS = 0) const {
323 return AS == 0 ? Data32bitsDirective : getDataASDirective(32, AS);
325 const char *getData64bitsDirective(unsigned AS = 0) const {
326 return AS == 0 ? Data64bitsDirective : getDataASDirective(64, AS);
332 const char *getZeroFillDirective() const {
333 return ZeroFillDirective;
335 const char *getNonexecutableStackDirective() const {
336 return NonexecutableStackDirective;
338 bool needsSet() const {
341 unsigned getMaxInstLength() const {
342 return MaxInstLength;
344 const char *getPCSymbol() const {
347 char getSeparatorChar() const {
348 return SeparatorChar;
350 unsigned getCommentColumn() const {
351 return CommentColumn;
353 const char *getCommentString() const {
354 return CommentString;
356 const char *getGlobalPrefix() const {
359 const char *getPrivateGlobalPrefix() const {
360 return PrivateGlobalPrefix;
362 const char *getLinkerPrivateGlobalPrefix() const {
363 return LinkerPrivateGlobalPrefix;
365 const char *getJumpTableSpecialLabelPrefix() const {
366 return JumpTableSpecialLabelPrefix;
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() const {
414 return 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 *getSwitchToSectionDirective() const {
426 return SwitchToSectionDirective;
428 const char *getGlobalDirective() const {
429 return GlobalDirective;
431 const char *getExternDirective() const {
432 return ExternDirective;
434 const char *getSetDirective() const {
437 const char *getLCOMMDirective() const {
438 return LCOMMDirective;
440 const char *getCOMMDirective() const {
441 return COMMDirective;
443 bool getCOMMDirectiveTakesAlignment() const {
444 return COMMDirectiveTakesAlignment;
446 bool hasDotTypeDotSizeDirective() const {
447 return HasDotTypeDotSizeDirective;
449 bool hasSingleParameterDotFile() const {
450 return HasSingleParameterDotFile;
452 const char *getUsedDirective() const {
453 return UsedDirective;
455 const char *getWeakRefDirective() const {
456 return WeakRefDirective;
458 const char *getWeakDefDirective() const {
459 return WeakDefDirective;
461 const char *getHiddenDirective() const {
462 return HiddenDirective;
464 const char *getProtectedDirective() const {
465 return ProtectedDirective;
467 bool isAbsoluteDebugSectionOffsets() const {
468 return AbsoluteDebugSectionOffsets;
470 bool isAbsoluteEHSectionOffsets() const {
471 return AbsoluteEHSectionOffsets;
473 bool hasLEB128() const {
476 bool hasDotLocAndDotFile() const {
477 return HasDotLocAndDotFile;
479 bool doesSupportDebugInformation() const {
480 return SupportsDebugInformation;
482 bool doesSupportExceptionHandling() const {
483 return SupportsExceptionHandling;
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 {