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 { enum ExceptionsType { None, Dwarf, SjLj }; }
32 //===------------------------------------------------------------------===//
33 // Properties to be set by the target writer, used to configure asm printer.
36 /// HasSubsectionsViaSymbols - True if this target has the MachO
37 /// .subsections_via_symbols directive.
38 bool HasSubsectionsViaSymbols; // Default is false.
40 /// HasMachoZeroFillDirective - True if this is a MachO target that supports
41 /// the macho-specific .zerofill directive for emitting BSS Symbols.
42 bool HasMachoZeroFillDirective; // Default is false.
44 /// HasStaticCtorDtorReferenceInStaticMode - True if the compiler should
45 /// emit a ".reference .constructors_used" or ".reference .destructors_used"
46 /// directive after the a static ctor/dtor list. This directive is only
47 /// emitted in Static relocation model.
48 bool HasStaticCtorDtorReferenceInStaticMode; // Default is false.
50 /// MaxInstLength - This is the maximum possible length of an instruction,
51 /// which is needed to compute the size of an inline asm.
52 unsigned MaxInstLength; // Defaults to 4.
54 /// PCSymbol - The symbol used to represent the current PC. Used in PC
55 /// relative expressions.
56 const char *PCSymbol; // Defaults to "$".
58 /// SeparatorChar - This character, if specified, is used to separate
59 /// instructions from each other when on the same line. This is used to
60 /// measure inline asm instructions.
61 char SeparatorChar; // Defaults to ';'
63 /// CommentColumn - This indicates the comment num (zero-based) at
64 /// which asm comments should be printed.
65 unsigned CommentColumn; // Defaults to 60
67 /// CommentString - This indicates the comment character used by the
69 const char *CommentString; // Defaults to "#"
71 /// GlobalPrefix - If this is set to a non-empty string, it is prepended
72 /// onto all global symbols. This is often used for "_" or ".".
73 const char *GlobalPrefix; // Defaults to ""
75 /// PrivateGlobalPrefix - This prefix is used for globals like constant
76 /// pool entries that are completely private to the .s file and should not
77 /// have names in the .o file. This is often "." or "L".
78 const char *PrivateGlobalPrefix; // Defaults to "."
80 /// LinkerPrivateGlobalPrefix - This prefix is used for symbols that should
81 /// be passed through the assembler but be removed by the linker. This
82 /// is "l" on Darwin, currently used for some ObjC metadata.
83 const char *LinkerPrivateGlobalPrefix; // Defaults to ""
85 /// InlineAsmStart/End - If these are nonempty, they contain a directive to
86 /// emit before and after an inline assembly statement.
87 const char *InlineAsmStart; // Defaults to "#APP\n"
88 const char *InlineAsmEnd; // Defaults to "#NO_APP\n"
90 /// AssemblerDialect - Which dialect of an assembler variant to use.
91 unsigned AssemblerDialect; // Defaults to 0
93 /// AllowQuotesInName - This is true if the assembler allows for complex
94 /// symbol names to be surrounded in quotes. This defaults to false.
95 bool AllowQuotesInName;
97 /// AllowNameToStartWithDigit - This is true if the assembler allows symbol
98 /// names to start with a digit (e.g., "0x0021"). This defaults to false.
99 bool AllowNameToStartWithDigit;
101 //===--- Data Emission Directives -------------------------------------===//
103 /// ZeroDirective - this should be set to the directive used to get some
104 /// number of zero bytes emitted to the current section. Common cases are
105 /// "\t.zero\t" and "\t.space\t". If this is set to null, the
106 /// Data*bitsDirective's will be used to emit zero bytes.
107 const char *ZeroDirective; // Defaults to "\t.zero\t"
109 /// AsciiDirective - This directive allows emission of an ascii string with
110 /// the standard C escape characters embedded into it.
111 const char *AsciiDirective; // Defaults to "\t.ascii\t"
113 /// AscizDirective - If not null, this allows for special handling of
114 /// zero terminated strings on this target. This is commonly supported as
115 /// ".asciz". If a target doesn't support this, it can be set to null.
116 const char *AscizDirective; // Defaults to "\t.asciz\t"
118 /// DataDirectives - These directives are used to output some unit of
119 /// integer data to the current section. If a data directive is set to
120 /// null, smaller data directives will be used to emit the large sizes.
121 const char *Data8bitsDirective; // Defaults to "\t.byte\t"
122 const char *Data16bitsDirective; // Defaults to "\t.short\t"
123 const char *Data32bitsDirective; // Defaults to "\t.long\t"
124 const char *Data64bitsDirective; // Defaults to "\t.quad\t"
126 /// GPRel32Directive - if non-null, a directive that is used to emit a word
127 /// which should be relocated as a 32-bit GP-relative offset, e.g. .gpword
128 /// on Mips or .gprel32 on Alpha.
129 const char *GPRel32Directive; // Defaults to NULL.
131 /// getDataASDirective - Return the directive that should be used to emit
132 /// data of the specified size to the specified numeric address space.
133 virtual const char *getDataASDirective(unsigned Size, unsigned AS) const {
134 assert(AS != 0 && "Don't know the directives for default addr space");
138 /// SunStyleELFSectionSwitchSyntax - This is true if this target uses "Sun
139 /// Style" syntax for section switching ("#alloc,#write" etc) instead of the
140 /// normal ELF syntax (,"a,w") in .section directives.
141 bool SunStyleELFSectionSwitchSyntax; // Defaults to false.
143 /// UsesELFSectionDirectiveForBSS - This is true if this target uses ELF
144 /// '.section' directive before the '.bss' one. It's used for PPC/Linux
145 /// which doesn't support the '.bss' directive only.
146 bool UsesELFSectionDirectiveForBSS; // Defaults to false.
148 //===--- Alignment Information ----------------------------------------===//
150 /// AlignDirective - The directive used to emit round up to an alignment
153 const char *AlignDirective; // Defaults to "\t.align\t"
155 /// AlignmentIsInBytes - If this is true (the default) then the asmprinter
156 /// emits ".align N" directives, where N is the number of bytes to align to.
157 /// Otherwise, it emits ".align log2(N)", e.g. 3 to align to an 8 byte
159 bool AlignmentIsInBytes; // Defaults to true
161 /// TextAlignFillValue - If non-zero, this is used to fill the executable
162 /// space created as the result of a alignment directive.
163 unsigned TextAlignFillValue; // Defaults to 0
165 //===--- Global Variable Emission Directives --------------------------===//
167 /// GlobalDirective - This is the directive used to declare a global entity.
169 const char *GlobalDirective; // Defaults to NULL.
171 /// ExternDirective - This is the directive used to declare external
174 const char *ExternDirective; // Defaults to NULL.
176 /// SetDirective - This is the name of a directive that can be used to tell
177 /// the assembler to set the value of a variable to some expression.
178 const char *SetDirective; // Defaults to null.
180 /// HasLCOMMDirective - This is true if the target supports the .lcomm
182 bool HasLCOMMDirective; // Defaults to false.
184 /// COMMDirectiveAlignmentIsInBytes - True is COMMDirective's optional
185 /// alignment is to be specified in bytes instead of log2(n).
186 bool COMMDirectiveAlignmentIsInBytes; // Defaults to true;
188 /// HasDotTypeDotSizeDirective - True if the target has .type and .size
189 /// directives, this is true for most ELF targets.
190 bool HasDotTypeDotSizeDirective; // Defaults to true.
192 /// HasSingleParameterDotFile - True if the target has a single parameter
193 /// .file directive, this is true for ELF targets.
194 bool HasSingleParameterDotFile; // Defaults to true.
196 /// HasNoDeadStrip - True if this target supports the MachO .no_dead_strip
198 bool HasNoDeadStrip; // Defaults to false.
200 /// WeakRefDirective - This directive, if non-null, is used to declare a
201 /// global as being a weak undefined symbol.
202 const char *WeakRefDirective; // Defaults to NULL.
204 /// WeakDefDirective - This directive, if non-null, is used to declare a
205 /// global as being a weak defined symbol.
206 const char *WeakDefDirective; // Defaults to NULL.
208 /// LinkOnceDirective - This directive, if non-null is used to declare a
209 /// global as being a weak defined symbol. This is used on cygwin/mingw.
210 const char *LinkOnceDirective; // Defaults to NULL.
212 /// HiddenVisibilityAttr - This attribute, if not MCSA_Invalid, is used to
213 /// declare a symbol as having hidden visibility.
214 MCSymbolAttr HiddenVisibilityAttr; // Defaults to MCSA_Hidden.
216 /// ProtectedVisibilityAttr - This attribute, if not MCSA_Invalid, is used
217 /// to declare a symbol as having protected visibility.
218 MCSymbolAttr ProtectedVisibilityAttr; // Defaults to MCSA_Protected
220 //===--- Dwarf Emission Directives -----------------------------------===//
222 /// AbsoluteDebugSectionOffsets - True if we should emit abolute section
223 /// offsets for debug information.
224 bool AbsoluteDebugSectionOffsets; // Defaults to false.
226 /// AbsoluteEHSectionOffsets - True if we should emit abolute section
227 /// offsets for EH information. Defaults to false.
228 bool AbsoluteEHSectionOffsets;
230 /// HasLEB128 - True if target asm supports leb128 directives.
231 bool HasLEB128; // Defaults to false.
233 /// hasDotLocAndDotFile - True if target asm supports .loc and .file
234 /// directives for emitting debugging information.
235 bool HasDotLocAndDotFile; // Defaults to false.
237 /// SupportsDebugInformation - True if target supports emission of debugging
239 bool SupportsDebugInformation; // Defaults to false.
241 /// SupportsExceptionHandling - True if target supports exception handling.
242 ExceptionHandling::ExceptionsType ExceptionsType; // Defaults to None
244 /// RequiresFrameSection - true if the Dwarf2 output needs a frame section
245 bool DwarfRequiresFrameSection; // Defaults to true.
247 /// DwarfUsesInlineInfoSection - True if DwarfDebugInlineSection is used to
248 /// encode inline subroutine information.
249 bool DwarfUsesInlineInfoSection; // Defaults to false.
251 /// Is_EHSymbolPrivate - If set, the "_foo.eh" is made private so that it
252 /// doesn't show up in the symbol table of the object file.
253 bool Is_EHSymbolPrivate; // Defaults to true.
255 /// GlobalEHDirective - This is the directive used to make exception frame
256 /// tables globally visible.
257 const char *GlobalEHDirective; // Defaults to NULL.
259 /// SupportsWeakEmptyEHFrame - True if target assembler and linker will
260 /// handle a weak_definition of constant 0 for an omitted EH frame.
261 bool SupportsWeakOmittedEHFrame; // Defaults to true.
263 /// DwarfSectionOffsetDirective - Special section offset directive.
264 const char* DwarfSectionOffsetDirective; // Defaults to NULL
266 //===--- CBE Asm Translation Table -----------------------------------===//
268 const char *const *AsmTransCBE; // Defaults to empty
271 explicit MCAsmInfo();
272 virtual ~MCAsmInfo();
274 // FIXME: move these methods to DwarfPrinter when the JIT stops using them.
275 static unsigned getSLEB128Size(int Value);
276 static unsigned getULEB128Size(unsigned Value);
278 bool hasSubsectionsViaSymbols() const { return HasSubsectionsViaSymbols; }
280 // Data directive accessors.
282 const char *getData8bitsDirective(unsigned AS = 0) const {
283 return AS == 0 ? Data8bitsDirective : getDataASDirective(8, AS);
285 const char *getData16bitsDirective(unsigned AS = 0) const {
286 return AS == 0 ? Data16bitsDirective : getDataASDirective(16, AS);
288 const char *getData32bitsDirective(unsigned AS = 0) const {
289 return AS == 0 ? Data32bitsDirective : getDataASDirective(32, AS);
291 const char *getData64bitsDirective(unsigned AS = 0) const {
292 return AS == 0 ? Data64bitsDirective : getDataASDirective(64, AS);
294 const char *getGPRel32Directive() const { return GPRel32Directive; }
296 /// getNonexecutableStackSection - Targets can implement this method to
297 /// specify a section to switch to if the translation unit doesn't have any
298 /// trampolines that require an executable stack.
299 virtual MCSection *getNonexecutableStackSection(MCContext &Ctx) const {
303 bool usesSunStyleELFSectionSwitchSyntax() const {
304 return SunStyleELFSectionSwitchSyntax;
307 bool usesELFSectionDirectiveForBSS() const {
308 return UsesELFSectionDirectiveForBSS;
313 bool hasMachoZeroFillDirective() const { return HasMachoZeroFillDirective; }
314 bool hasStaticCtorDtorReferenceInStaticMode() const {
315 return HasStaticCtorDtorReferenceInStaticMode;
317 unsigned getMaxInstLength() const {
318 return MaxInstLength;
320 const char *getPCSymbol() const {
323 char getSeparatorChar() const {
324 return SeparatorChar;
326 unsigned getCommentColumn() const {
327 return CommentColumn;
329 const char *getCommentString() const {
330 return CommentString;
332 const char *getGlobalPrefix() const {
335 const char *getPrivateGlobalPrefix() const {
336 return PrivateGlobalPrefix;
338 const char *getLinkerPrivateGlobalPrefix() const {
339 return LinkerPrivateGlobalPrefix;
341 const char *getInlineAsmStart() const {
342 return InlineAsmStart;
344 const char *getInlineAsmEnd() const {
347 unsigned getAssemblerDialect() const {
348 return AssemblerDialect;
350 bool doesAllowQuotesInName() const {
351 return AllowQuotesInName;
353 bool doesAllowNameToStartWithDigit() const {
354 return AllowNameToStartWithDigit;
356 const char *getZeroDirective() const {
357 return ZeroDirective;
359 const char *getAsciiDirective() const {
360 return AsciiDirective;
362 const char *getAscizDirective() const {
363 return AscizDirective;
365 const char *getAlignDirective() const {
366 return AlignDirective;
368 bool getAlignmentIsInBytes() const {
369 return AlignmentIsInBytes;
371 unsigned getTextAlignFillValue() const {
372 return TextAlignFillValue;
374 const char *getGlobalDirective() const {
375 return GlobalDirective;
377 const char *getExternDirective() const {
378 return ExternDirective;
380 const char *getSetDirective() const {
383 bool hasLCOMMDirective() const { return HasLCOMMDirective; }
384 bool hasDotTypeDotSizeDirective() const {return HasDotTypeDotSizeDirective;}
385 bool getCOMMDirectiveAlignmentIsInBytes() const {
386 return COMMDirectiveAlignmentIsInBytes;
388 bool hasSingleParameterDotFile() const { return HasSingleParameterDotFile; }
389 bool hasNoDeadStrip() const { return HasNoDeadStrip; }
390 const char *getWeakRefDirective() const { return WeakRefDirective; }
391 const char *getWeakDefDirective() const { return WeakDefDirective; }
392 const char *getLinkOnceDirective() const { return LinkOnceDirective; }
394 MCSymbolAttr getHiddenVisibilityAttr() const { return HiddenVisibilityAttr;}
395 MCSymbolAttr getProtectedVisibilityAttr() const {
396 return ProtectedVisibilityAttr;
398 bool isAbsoluteDebugSectionOffsets() const {
399 return AbsoluteDebugSectionOffsets;
401 bool isAbsoluteEHSectionOffsets() const {
402 return AbsoluteEHSectionOffsets;
404 bool hasLEB128() const {
407 bool hasDotLocAndDotFile() const {
408 return HasDotLocAndDotFile;
410 bool doesSupportDebugInformation() const {
411 return SupportsDebugInformation;
413 bool doesSupportExceptionHandling() const {
414 return ExceptionsType != ExceptionHandling::None;
416 ExceptionHandling::ExceptionsType getExceptionHandlingType() const {
417 return ExceptionsType;
419 bool doesDwarfRequireFrameSection() const {
420 return DwarfRequiresFrameSection;
422 bool doesDwarfUsesInlineInfoSection() const {
423 return DwarfUsesInlineInfoSection;
425 bool is_EHSymbolPrivate() const {
426 return Is_EHSymbolPrivate;
428 const char *getGlobalEHDirective() const {
429 return GlobalEHDirective;
431 bool getSupportsWeakOmittedEHFrame() const {
432 return SupportsWeakOmittedEHFrame;
434 const char *getDwarfSectionOffsetDirective() const {
435 return DwarfSectionOffsetDirective;
437 const char *const *getAsmCBE() const {