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 /// NeedsSet - True if target asm treats expressions in data directives
51 /// as linktime-relocatable. For assembly-time computation, we need to
55 /// is computed at assembly time, while
57 /// is relocated if the relative locations of x and y change at linktime.
58 /// We want both these things in different places.
59 bool NeedsSet; // Defaults 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 60
78 /// CommentString - This indicates the comment character used by the
80 const char *CommentString; // Defaults to "#"
82 /// GlobalPrefix - If this is set to a non-empty string, it is prepended
83 /// onto all global symbols. This is often used for "_" or ".".
84 const char *GlobalPrefix; // Defaults to ""
86 /// PrivateGlobalPrefix - This prefix is used for globals like constant
87 /// pool entries that are completely private to the .s file and should not
88 /// have names in the .o file. This is often "." or "L".
89 const char *PrivateGlobalPrefix; // Defaults to "."
91 /// LinkerPrivateGlobalPrefix - This prefix is used for symbols that should
92 /// be passed through the assembler but be removed by the linker. This
93 /// is "l" on Darwin, currently used for some ObjC metadata.
94 const char *LinkerPrivateGlobalPrefix; // Defaults to ""
96 /// InlineAsmStart/End - If these are nonempty, they contain a directive to
97 /// emit before and after an inline assembly statement.
98 const char *InlineAsmStart; // Defaults to "#APP\n"
99 const char *InlineAsmEnd; // Defaults to "#NO_APP\n"
101 /// AssemblerDialect - Which dialect of an assembler variant to use.
102 unsigned AssemblerDialect; // Defaults to 0
104 /// AllowQuotesInName - This is true if the assembler allows for complex
105 /// symbol names to be surrounded in quotes. This defaults to false.
106 bool AllowQuotesInName;
108 /// AllowNameToStartWithDigit - This is true if the assembler allows symbol
109 /// names to start with a digit (e.g., "0x0021"). This defaults to false.
110 bool AllowNameToStartWithDigit;
112 //===--- Data Emission Directives -------------------------------------===//
114 /// ZeroDirective - this should be set to the directive used to get some
115 /// number of zero bytes emitted to the current section. Common cases are
116 /// "\t.zero\t" and "\t.space\t". If this is set to null, the
117 /// Data*bitsDirective's will be used to emit zero bytes.
118 const char *ZeroDirective; // Defaults to "\t.zero\t"
120 /// AsciiDirective - This directive allows emission of an ascii string with
121 /// the standard C escape characters embedded into it.
122 const char *AsciiDirective; // Defaults to "\t.ascii\t"
124 /// AscizDirective - If not null, this allows for special handling of
125 /// zero terminated strings on this target. This is commonly supported as
126 /// ".asciz". If a target doesn't support this, it can be set to null.
127 const char *AscizDirective; // Defaults to "\t.asciz\t"
129 /// DataDirectives - These directives are used to output some unit of
130 /// integer data to the current section. If a data directive is set to
131 /// null, smaller data directives will be used to emit the large sizes.
132 const char *Data8bitsDirective; // Defaults to "\t.byte\t"
133 const char *Data16bitsDirective; // Defaults to "\t.short\t"
134 const char *Data32bitsDirective; // Defaults to "\t.long\t"
135 const char *Data64bitsDirective; // Defaults to "\t.quad\t"
137 /// getDataASDirective - Return the directive that should be used to emit
138 /// data of the specified size to the specified numeric address space.
139 virtual const char *getDataASDirective(unsigned Size, unsigned AS) const {
140 assert(AS != 0 && "Don't know the directives for default addr space");
144 /// SunStyleELFSectionSwitchSyntax - This is true if this target uses "Sun
145 /// Style" syntax for section switching ("#alloc,#write" etc) instead of the
146 /// normal ELF syntax (,"a,w") in .section directives.
147 bool SunStyleELFSectionSwitchSyntax; // Defaults to false.
149 /// UsesELFSectionDirectiveForBSS - This is true if this target uses ELF
150 /// '.section' directive before the '.bss' one. It's used for PPC/Linux
151 /// which doesn't support the '.bss' directive only.
152 bool UsesELFSectionDirectiveForBSS; // Defaults to false.
154 //===--- Alignment Information ----------------------------------------===//
156 /// AlignDirective - The directive used to emit round up to an alignment
159 const char *AlignDirective; // Defaults to "\t.align\t"
161 /// AlignmentIsInBytes - If this is true (the default) then the asmprinter
162 /// emits ".align N" directives, where N is the number of bytes to align to.
163 /// Otherwise, it emits ".align log2(N)", e.g. 3 to align to an 8 byte
165 bool AlignmentIsInBytes; // Defaults to true
167 /// TextAlignFillValue - If non-zero, this is used to fill the executable
168 /// space created as the result of a alignment directive.
169 unsigned TextAlignFillValue; // Defaults to 0
171 //===--- Section Switching Directives ---------------------------------===//
173 /// PICJumpTableDirective - if non-null, the directive to emit before jump
174 /// table entries. FIXME: REMOVE THIS.
175 const char *PICJumpTableDirective; // Defaults to NULL.
178 //===--- Global Variable Emission Directives --------------------------===//
180 /// GlobalDirective - This is the directive used to declare a global entity.
182 const char *GlobalDirective; // Defaults to NULL.
184 /// ExternDirective - This is the directive used to declare external
187 const char *ExternDirective; // Defaults to NULL.
189 /// SetDirective - This is the name of a directive that can be used to tell
190 /// the assembler to set the value of a variable to some expression.
191 const char *SetDirective; // Defaults to null.
193 /// HasLCOMMDirective - This is true if the target supports the .lcomm
195 bool HasLCOMMDirective; // Defaults to false.
197 /// HasDotTypeDotSizeDirective - True if the target has .type and .size
198 /// directives, this is true for most ELF targets.
199 bool HasDotTypeDotSizeDirective; // Defaults to true.
201 /// HasSingleParameterDotFile - True if the target has a single parameter
202 /// .file directive, this is true for ELF targets.
203 bool HasSingleParameterDotFile; // Defaults to true.
205 /// HasNoDeadStrip - True if this target supports the MachO .no_dead_strip
207 bool HasNoDeadStrip; // Defaults to false.
209 /// WeakRefDirective - This directive, if non-null, is used to declare a
210 /// global as being a weak undefined symbol.
211 const char *WeakRefDirective; // Defaults to NULL.
213 /// WeakDefDirective - This directive, if non-null, is used to declare a
214 /// global as being a weak defined symbol.
215 const char *WeakDefDirective; // Defaults to NULL.
217 /// LinkOnceDirective - This directive, if non-null is used to declare a
218 /// global as being a weak defined symbol. This is used on cygwin/mingw.
219 const char *LinkOnceDirective; // Defaults to NULL.
221 /// HiddenVisibilityAttr - This attribute, if not MCSA_Invalid, is used to
222 /// declare a symbol as having hidden visibility.
223 MCSymbolAttr HiddenVisibilityAttr; // Defaults to MCSA_Hidden.
225 /// ProtectedVisibilityAttr - This attribute, if not MCSA_Invalid, is used
226 /// to declare a symbol as having protected visibility.
227 MCSymbolAttr ProtectedVisibilityAttr; // Defaults to MCSA_Protected
229 //===--- Dwarf Emission Directives -----------------------------------===//
231 /// AbsoluteDebugSectionOffsets - True if we should emit abolute section
232 /// offsets for debug information.
233 bool AbsoluteDebugSectionOffsets; // Defaults to false.
235 /// AbsoluteEHSectionOffsets - True if we should emit abolute section
236 /// offsets for EH information. Defaults to false.
237 bool AbsoluteEHSectionOffsets;
239 /// HasLEB128 - True if target asm supports leb128 directives.
240 bool HasLEB128; // Defaults to false.
242 /// hasDotLocAndDotFile - True if target asm supports .loc and .file
243 /// directives for emitting debugging information.
244 bool HasDotLocAndDotFile; // Defaults to false.
246 /// SupportsDebugInformation - True if target supports emission of debugging
248 bool SupportsDebugInformation; // Defaults to false.
250 /// SupportsExceptionHandling - True if target supports exception handling.
251 ExceptionHandling::ExceptionsType ExceptionsType; // Defaults to None
253 /// RequiresFrameSection - true if the Dwarf2 output needs a frame section
254 bool DwarfRequiresFrameSection; // Defaults to true.
256 /// DwarfUsesInlineInfoSection - True if DwarfDebugInlineSection is used to
257 /// encode inline subroutine information.
258 bool DwarfUsesInlineInfoSection; // Defaults to false.
260 /// Is_EHSymbolPrivate - If set, the "_foo.eh" is made private so that it
261 /// doesn't show up in the symbol table of the object file.
262 bool Is_EHSymbolPrivate; // Defaults to true.
264 /// GlobalEHDirective - This is the directive used to make exception frame
265 /// tables globally visible.
266 const char *GlobalEHDirective; // Defaults to NULL.
268 /// SupportsWeakEmptyEHFrame - True if target assembler and linker will
269 /// handle a weak_definition of constant 0 for an omitted EH frame.
270 bool SupportsWeakOmittedEHFrame; // Defaults to true.
272 /// DwarfSectionOffsetDirective - Special section offset directive.
273 const char* DwarfSectionOffsetDirective; // Defaults to NULL
275 //===--- CBE Asm Translation Table -----------------------------------===//
277 const char *const *AsmTransCBE; // Defaults to empty
280 explicit MCAsmInfo();
281 virtual ~MCAsmInfo();
283 // FIXME: move these methods to DwarfPrinter when the JIT stops using them.
284 static unsigned getSLEB128Size(int Value);
285 static unsigned getULEB128Size(unsigned Value);
287 bool hasSubsectionsViaSymbols() const { return HasSubsectionsViaSymbols; }
289 // Data directive accessors.
291 const char *getData8bitsDirective(unsigned AS = 0) const {
292 return AS == 0 ? Data8bitsDirective : getDataASDirective(8, AS);
294 const char *getData16bitsDirective(unsigned AS = 0) const {
295 return AS == 0 ? Data16bitsDirective : getDataASDirective(16, AS);
297 const char *getData32bitsDirective(unsigned AS = 0) const {
298 return AS == 0 ? Data32bitsDirective : getDataASDirective(32, AS);
300 const char *getData64bitsDirective(unsigned AS = 0) const {
301 return AS == 0 ? Data64bitsDirective : getDataASDirective(64, AS);
304 /// getNonexecutableStackSection - Targets can implement this method to
305 /// specify a section to switch to if the translation unit doesn't have any
306 /// trampolines that require an executable stack.
307 virtual MCSection *getNonexecutableStackSection(MCContext &Ctx) const {
311 bool usesSunStyleELFSectionSwitchSyntax() const {
312 return SunStyleELFSectionSwitchSyntax;
315 bool usesELFSectionDirectiveForBSS() const {
316 return UsesELFSectionDirectiveForBSS;
321 bool hasMachoZeroFillDirective() const { return HasMachoZeroFillDirective; }
322 bool hasStaticCtorDtorReferenceInStaticMode() const {
323 return HasStaticCtorDtorReferenceInStaticMode;
325 bool needsSet() const {
328 unsigned getMaxInstLength() const {
329 return MaxInstLength;
331 const char *getPCSymbol() const {
334 char getSeparatorChar() const {
335 return SeparatorChar;
337 unsigned getCommentColumn() const {
338 return CommentColumn;
340 const char *getCommentString() const {
341 return CommentString;
343 const char *getGlobalPrefix() const {
346 const char *getPrivateGlobalPrefix() const {
347 return PrivateGlobalPrefix;
349 const char *getLinkerPrivateGlobalPrefix() const {
350 return LinkerPrivateGlobalPrefix;
352 const char *getInlineAsmStart() const {
353 return InlineAsmStart;
355 const char *getInlineAsmEnd() const {
358 unsigned getAssemblerDialect() const {
359 return AssemblerDialect;
361 bool doesAllowQuotesInName() const {
362 return AllowQuotesInName;
364 bool doesAllowNameToStartWithDigit() const {
365 return AllowNameToStartWithDigit;
367 const char *getZeroDirective() const {
368 return ZeroDirective;
370 const char *getAsciiDirective() const {
371 return AsciiDirective;
373 const char *getAscizDirective() const {
374 return AscizDirective;
376 const char *getPICJumpTableDirective() const {
377 return PICJumpTableDirective;
379 const char *getAlignDirective() const {
380 return AlignDirective;
382 bool getAlignmentIsInBytes() const {
383 return AlignmentIsInBytes;
385 unsigned getTextAlignFillValue() const {
386 return TextAlignFillValue;
388 const char *getGlobalDirective() const {
389 return GlobalDirective;
391 const char *getExternDirective() const {
392 return ExternDirective;
394 const char *getSetDirective() const {
397 bool hasLCOMMDirective() const { return HasLCOMMDirective; }
398 bool hasDotTypeDotSizeDirective() const {return HasDotTypeDotSizeDirective;}
399 bool hasSingleParameterDotFile() const { return HasSingleParameterDotFile; }
400 bool hasNoDeadStrip() const { return HasNoDeadStrip; }
401 const char *getWeakRefDirective() const { return WeakRefDirective; }
402 const char *getWeakDefDirective() const { return WeakDefDirective; }
403 const char *getLinkOnceDirective() const { return LinkOnceDirective; }
405 MCSymbolAttr getHiddenVisibilityAttr() const { return HiddenVisibilityAttr;}
406 MCSymbolAttr getProtectedVisibilityAttr() const {
407 return ProtectedVisibilityAttr;
409 bool isAbsoluteDebugSectionOffsets() const {
410 return AbsoluteDebugSectionOffsets;
412 bool isAbsoluteEHSectionOffsets() const {
413 return AbsoluteEHSectionOffsets;
415 bool hasLEB128() const {
418 bool hasDotLocAndDotFile() const {
419 return HasDotLocAndDotFile;
421 bool doesSupportDebugInformation() const {
422 return SupportsDebugInformation;
424 bool doesSupportExceptionHandling() const {
425 return ExceptionsType != ExceptionHandling::None;
427 ExceptionHandling::ExceptionsType getExceptionHandlingType() const {
428 return ExceptionsType;
430 bool doesDwarfRequireFrameSection() const {
431 return DwarfRequiresFrameSection;
433 bool doesDwarfUsesInlineInfoSection() const {
434 return DwarfUsesInlineInfoSection;
436 bool is_EHSymbolPrivate() const {
437 return Is_EHSymbolPrivate;
439 const char *getGlobalEHDirective() const {
440 return GlobalEHDirective;
442 bool getSupportsWeakOmittedEHFrame() const {
443 return SupportsWeakOmittedEHFrame;
445 const char *getDwarfSectionOffsetDirective() const {
446 return DwarfSectionOffsetDirective;
448 const char *const *getAsmCBE() const {