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/MC/MCDirectives.h"
26 /// MCAsmInfo - This class is intended to be used as a base class for asm
27 /// properties and features specific to the target.
28 namespace ExceptionHandling {
29 enum ExceptionsType { None, DwarfTable, DwarfCFI, SjLj };
34 //===------------------------------------------------------------------===//
35 // Properties to be set by the target writer, used to configure asm printer.
38 /// HasSubsectionsViaSymbols - True if this target has the MachO
39 /// .subsections_via_symbols directive.
40 bool HasSubsectionsViaSymbols; // Default is false.
42 /// HasMachoZeroFillDirective - True if this is a MachO target that supports
43 /// the macho-specific .zerofill directive for emitting BSS Symbols.
44 bool HasMachoZeroFillDirective; // Default is false.
46 /// HasMachoTBSSDirective - True if this is a MachO target that supports
47 /// the macho-specific .tbss directive for emitting thread local BSS Symbols
48 bool HasMachoTBSSDirective; // Default is false.
50 /// HasStaticCtorDtorReferenceInStaticMode - True if the compiler should
51 /// emit a ".reference .constructors_used" or ".reference .destructors_used"
52 /// directive after the a static ctor/dtor list. This directive is only
53 /// emitted in Static relocation model.
54 bool HasStaticCtorDtorReferenceInStaticMode; // Default is false.
56 /// LinkerRequiresNonEmptyDwarfLines - True if the linker has a bug and
57 /// requires that the debug_line section be of a minimum size. In practice
58 /// such a linker requires a non empty line sequence if a file is present.
59 bool LinkerRequiresNonEmptyDwarfLines; // Default to false.
61 /// MaxInstLength - This is the maximum possible length of an instruction,
62 /// which is needed to compute the size of an inline asm.
63 unsigned MaxInstLength; // Defaults to 4.
65 /// PCSymbol - The symbol used to represent the current PC. Used in PC
66 /// relative expressions.
67 const char *PCSymbol; // Defaults to "$".
69 /// SeparatorChar - This character, if specified, is used to separate
70 /// instructions from each other when on the same line. This is used to
71 /// measure inline asm instructions.
72 char SeparatorChar; // Defaults to ';'
74 /// CommentColumn - This indicates the comment num (zero-based) at
75 /// which asm comments should be printed.
76 unsigned CommentColumn; // Defaults to 40
78 /// CommentString - This indicates the comment character used by the
80 const char *CommentString; // Defaults to "#"
82 /// LabelSuffix - This is appended to emitted labels.
83 const char *LabelSuffix; // Defaults to ":"
85 /// GlobalPrefix - If this is set to a non-empty string, it is prepended
86 /// onto all global symbols. This is often used for "_" or ".".
87 const char *GlobalPrefix; // Defaults to ""
89 /// PrivateGlobalPrefix - This prefix is used for globals like constant
90 /// pool entries that are completely private to the .s file and should not
91 /// have names in the .o file. This is often "." or "L".
92 const char *PrivateGlobalPrefix; // Defaults to "."
94 /// LinkerPrivateGlobalPrefix - This prefix is used for symbols that should
95 /// be passed through the assembler but be removed by the linker. This
96 /// is "l" on Darwin, currently used for some ObjC metadata.
97 const char *LinkerPrivateGlobalPrefix; // Defaults to ""
99 /// InlineAsmStart/End - If these are nonempty, they contain a directive to
100 /// emit before and after an inline assembly statement.
101 const char *InlineAsmStart; // Defaults to "#APP\n"
102 const char *InlineAsmEnd; // Defaults to "#NO_APP\n"
104 /// AssemblerDialect - Which dialect of an assembler variant to use.
105 unsigned AssemblerDialect; // Defaults to 0
107 /// AllowQuotesInName - This is true if the assembler allows for complex
108 /// symbol names to be surrounded in quotes. This defaults to false.
109 bool AllowQuotesInName;
111 /// AllowNameToStartWithDigit - This is true if the assembler allows symbol
112 /// names to start with a digit (e.g., "0x0021"). This defaults to false.
113 bool AllowNameToStartWithDigit;
115 /// AllowPeriodsInName - This is true if the assembler allows periods in
116 /// symbol names. This defaults to true.
117 bool AllowPeriodsInName;
119 //===--- Data Emission Directives -------------------------------------===//
121 /// ZeroDirective - this should be set to the directive used to get some
122 /// number of zero bytes emitted to the current section. Common cases are
123 /// "\t.zero\t" and "\t.space\t". If this is set to null, the
124 /// Data*bitsDirective's will be used to emit zero bytes.
125 const char *ZeroDirective; // Defaults to "\t.zero\t"
127 /// AsciiDirective - This directive allows emission of an ascii string with
128 /// the standard C escape characters embedded into it.
129 const char *AsciiDirective; // Defaults to "\t.ascii\t"
131 /// AscizDirective - If not null, this allows for special handling of
132 /// zero terminated strings on this target. This is commonly supported as
133 /// ".asciz". If a target doesn't support this, it can be set to null.
134 const char *AscizDirective; // Defaults to "\t.asciz\t"
136 /// DataDirectives - These directives are used to output some unit of
137 /// integer data to the current section. If a data directive is set to
138 /// null, smaller data directives will be used to emit the large sizes.
139 const char *Data8bitsDirective; // Defaults to "\t.byte\t"
140 const char *Data16bitsDirective; // Defaults to "\t.short\t"
141 const char *Data32bitsDirective; // Defaults to "\t.long\t"
142 const char *Data64bitsDirective; // Defaults to "\t.quad\t"
144 /// GPRel32Directive - if non-null, a directive that is used to emit a word
145 /// which should be relocated as a 32-bit GP-relative offset, e.g. .gpword
146 /// on Mips or .gprel32 on Alpha.
147 const char *GPRel32Directive; // Defaults to NULL.
149 /// getDataASDirective - Return the directive that should be used to emit
150 /// data of the specified size to the specified numeric address space.
151 virtual const char *getDataASDirective(unsigned Size, unsigned AS) const {
152 assert(AS != 0 && "Don't know the directives for default addr space");
156 /// SunStyleELFSectionSwitchSyntax - This is true if this target uses "Sun
157 /// Style" syntax for section switching ("#alloc,#write" etc) instead of the
158 /// normal ELF syntax (,"a,w") in .section directives.
159 bool SunStyleELFSectionSwitchSyntax; // Defaults to false.
161 /// UsesELFSectionDirectiveForBSS - This is true if this target uses ELF
162 /// '.section' directive before the '.bss' one. It's used for PPC/Linux
163 /// which doesn't support the '.bss' directive only.
164 bool UsesELFSectionDirectiveForBSS; // Defaults to false.
166 /// HasMicrosoftFastStdCallMangling - True if this target uses microsoft
167 /// style mangling for functions with X86_StdCall/X86_FastCall calling
169 bool HasMicrosoftFastStdCallMangling; // Defaults to false.
171 //===--- Alignment Information ----------------------------------------===//
173 /// AlignDirective - The directive used to emit round up to an alignment
176 const char *AlignDirective; // Defaults to "\t.align\t"
178 /// AlignmentIsInBytes - If this is true (the default) then the asmprinter
179 /// emits ".align N" directives, where N is the number of bytes to align to.
180 /// Otherwise, it emits ".align log2(N)", e.g. 3 to align to an 8 byte
182 bool AlignmentIsInBytes; // Defaults to true
184 /// TextAlignFillValue - If non-zero, this is used to fill the executable
185 /// space created as the result of a alignment directive.
186 unsigned TextAlignFillValue; // Defaults to 0
188 //===--- Global Variable Emission Directives --------------------------===//
190 /// GlobalDirective - This is the directive used to declare a global entity.
192 const char *GlobalDirective; // Defaults to NULL.
194 /// ExternDirective - This is the directive used to declare external
197 const char *ExternDirective; // Defaults to NULL.
199 /// HasSetDirective - True if the assembler supports the .set directive.
200 bool HasSetDirective; // Defaults to true.
202 /// HasAggressiveSymbolFolding - False if the assembler requires that we use
207 bool HasAggressiveSymbolFolding; // Defaults to true.
209 /// HasLCOMMDirective - This is true if the target supports the .lcomm
211 bool HasLCOMMDirective; // Defaults to false.
213 /// COMMDirectiveAlignmentIsInBytes - True is COMMDirective's optional
214 /// alignment is to be specified in bytes instead of log2(n).
215 bool COMMDirectiveAlignmentIsInBytes; // 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 /// HasNoDeadStrip - True if this target supports the MachO .no_dead_strip
227 bool HasNoDeadStrip; // Defaults to false.
229 /// HasSymbolResolver - True if this target supports the MachO
230 /// .symbol_resolver directive.
231 bool HasSymbolResolver; // Defaults to false.
233 /// WeakRefDirective - This directive, if non-null, is used to declare a
234 /// global as being a weak undefined symbol.
235 const char *WeakRefDirective; // Defaults to NULL.
237 /// WeakDefDirective - This directive, if non-null, is used to declare a
238 /// global as being a weak defined symbol.
239 const char *WeakDefDirective; // Defaults to NULL.
241 /// LinkOnceDirective - This directive, if non-null is used to declare a
242 /// global as being a weak defined symbol. This is used on cygwin/mingw.
243 const char *LinkOnceDirective; // Defaults to NULL.
245 /// HiddenVisibilityAttr - This attribute, if not MCSA_Invalid, is used to
246 /// declare a symbol as having hidden visibility.
247 MCSymbolAttr HiddenVisibilityAttr; // Defaults to MCSA_Hidden.
249 /// ProtectedVisibilityAttr - This attribute, if not MCSA_Invalid, is used
250 /// to declare a symbol as having protected visibility.
251 MCSymbolAttr ProtectedVisibilityAttr; // Defaults to MCSA_Protected
253 //===--- Dwarf Emission Directives -----------------------------------===//
255 /// HasLEB128 - True if target asm supports leb128 directives.
256 bool HasLEB128; // Defaults to false.
258 /// SupportsDebugInformation - True if target supports emission of debugging
260 bool SupportsDebugInformation; // Defaults to false.
262 /// SupportsExceptionHandling - True if target supports exception handling.
263 ExceptionHandling::ExceptionsType ExceptionsType; // Defaults to None
265 /// RequiresFrameSection - true if the Dwarf2 output needs a frame section
266 bool DwarfRequiresFrameSection; // Defaults to true.
268 /// DwarfUsesInlineInfoSection - True if DwarfDebugInlineSection is used to
269 /// encode inline subroutine information.
270 bool DwarfUsesInlineInfoSection; // Defaults to false.
272 /// DwarfSectionOffsetDirective - Special section offset directive.
273 const char* DwarfSectionOffsetDirective; // Defaults to NULL
275 /// DwarfUsesAbsoluteLabelForStmtList - True if DW_AT_stmt_list needs
276 /// absolute label instead of offset.
277 bool DwarfUsesAbsoluteLabelForStmtList; // Defaults to true;
279 // DwarfUsesLabelOffsetDifference - True if Dwarf2 output can
280 // use EmitLabelOffsetDifference.
281 bool DwarfUsesLabelOffsetForRanges;
283 //===--- CBE Asm Translation Table -----------------------------------===//
285 const char *const *AsmTransCBE; // Defaults to empty
288 explicit MCAsmInfo();
289 virtual ~MCAsmInfo();
291 // FIXME: move these methods to DwarfPrinter when the JIT stops using them.
292 static unsigned getSLEB128Size(int Value);
293 static unsigned getULEB128Size(unsigned Value);
295 bool hasSubsectionsViaSymbols() const { return HasSubsectionsViaSymbols; }
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);
311 const char *getGPRel32Directive() const { return GPRel32Directive; }
313 /// getNonexecutableStackSection - Targets can implement this method to
314 /// specify a section to switch to if the translation unit doesn't have any
315 /// trampolines that require an executable stack.
316 virtual const MCSection *getNonexecutableStackSection(MCContext &Ctx) const{
320 bool usesSunStyleELFSectionSwitchSyntax() const {
321 return SunStyleELFSectionSwitchSyntax;
324 bool usesELFSectionDirectiveForBSS() const {
325 return UsesELFSectionDirectiveForBSS;
328 bool hasMicrosoftFastStdCallMangling() const {
329 return HasMicrosoftFastStdCallMangling;
334 bool hasMachoZeroFillDirective() const { return HasMachoZeroFillDirective; }
335 bool hasMachoTBSSDirective() const { return HasMachoTBSSDirective; }
336 bool hasStaticCtorDtorReferenceInStaticMode() const {
337 return HasStaticCtorDtorReferenceInStaticMode;
339 bool getLinkerRequiresNonEmptyDwarfLines() const {
340 return LinkerRequiresNonEmptyDwarfLines;
342 unsigned getMaxInstLength() const {
343 return MaxInstLength;
345 const char *getPCSymbol() const {
348 char getSeparatorChar() const {
349 return SeparatorChar;
351 unsigned getCommentColumn() const {
352 return CommentColumn;
354 const char *getCommentString() const {
355 return CommentString;
357 const char *getLabelSuffix() const {
360 const char *getGlobalPrefix() const {
363 const char *getPrivateGlobalPrefix() const {
364 return PrivateGlobalPrefix;
366 const char *getLinkerPrivateGlobalPrefix() const {
367 return LinkerPrivateGlobalPrefix;
369 const char *getInlineAsmStart() const {
370 return InlineAsmStart;
372 const char *getInlineAsmEnd() const {
375 unsigned getAssemblerDialect() const {
376 return AssemblerDialect;
378 bool doesAllowQuotesInName() const {
379 return AllowQuotesInName;
381 bool doesAllowNameToStartWithDigit() const {
382 return AllowNameToStartWithDigit;
384 bool doesAllowPeriodsInName() const {
385 return AllowPeriodsInName;
387 const char *getZeroDirective() const {
388 return ZeroDirective;
390 const char *getAsciiDirective() const {
391 return AsciiDirective;
393 const char *getAscizDirective() const {
394 return AscizDirective;
396 const char *getAlignDirective() const {
397 return AlignDirective;
399 bool getAlignmentIsInBytes() const {
400 return AlignmentIsInBytes;
402 unsigned getTextAlignFillValue() const {
403 return TextAlignFillValue;
405 const char *getGlobalDirective() const {
406 return GlobalDirective;
408 const char *getExternDirective() const {
409 return ExternDirective;
411 bool hasSetDirective() const { return HasSetDirective; }
412 bool hasAggressiveSymbolFolding() const {
413 return HasAggressiveSymbolFolding;
415 bool hasLCOMMDirective() const { return HasLCOMMDirective; }
416 bool hasDotTypeDotSizeDirective() const {return HasDotTypeDotSizeDirective;}
417 bool getCOMMDirectiveAlignmentIsInBytes() const {
418 return COMMDirectiveAlignmentIsInBytes;
420 bool hasSingleParameterDotFile() const { return HasSingleParameterDotFile; }
421 bool hasNoDeadStrip() const { return HasNoDeadStrip; }
422 bool hasSymbolResolver() const { return HasSymbolResolver; }
423 const char *getWeakRefDirective() const { return WeakRefDirective; }
424 const char *getWeakDefDirective() const { return WeakDefDirective; }
425 const char *getLinkOnceDirective() const { return LinkOnceDirective; }
427 MCSymbolAttr getHiddenVisibilityAttr() const { return HiddenVisibilityAttr;}
428 MCSymbolAttr getProtectedVisibilityAttr() const {
429 return ProtectedVisibilityAttr;
431 bool hasLEB128() const {
434 bool doesSupportDebugInformation() const {
435 return SupportsDebugInformation;
437 bool doesSupportExceptionHandling() const {
438 return ExceptionsType != ExceptionHandling::None;
440 ExceptionHandling::ExceptionsType getExceptionHandlingType() const {
441 return ExceptionsType;
443 bool isExceptionHandlingDwarf() const {
445 (ExceptionsType == ExceptionHandling::DwarfTable ||
446 ExceptionsType == ExceptionHandling::DwarfCFI);
449 bool doesDwarfRequireFrameSection() const {
450 return DwarfRequiresFrameSection;
452 bool doesDwarfUsesInlineInfoSection() const {
453 return DwarfUsesInlineInfoSection;
455 const char *getDwarfSectionOffsetDirective() const {
456 return DwarfSectionOffsetDirective;
458 bool doesDwarfUsesAbsoluteLabelForStmtList() const {
459 return DwarfUsesAbsoluteLabelForStmtList;
461 bool doesDwarfUsesLabelOffsetForRanges() const {
462 return DwarfUsesLabelOffsetForRanges;
464 const char *const *getAsmCBE() const {