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 /// JumpTableDirective - if non-null, the directive to emit before jump
174 /// table entries. FIXME: REMOVE THIS.
175 const char *JumpTableDirective; // Defaults to NULL.
176 const char *PICJumpTableDirective; // Defaults to NULL.
179 //===--- Global Variable Emission Directives --------------------------===//
181 /// GlobalDirective - This is the directive used to declare a global entity.
183 const char *GlobalDirective; // Defaults to NULL.
185 /// ExternDirective - This is the directive used to declare external
188 const char *ExternDirective; // Defaults to NULL.
190 /// SetDirective - This is the name of a directive that can be used to tell
191 /// the assembler to set the value of a variable to some expression.
192 const char *SetDirective; // Defaults to null.
194 /// HasLCOMMDirective - This is true if the target supports the .lcomm
196 bool HasLCOMMDirective; // Defaults to false.
198 /// HasDotTypeDotSizeDirective - True if the target has .type and .size
199 /// directives, this is true for most ELF targets.
200 bool HasDotTypeDotSizeDirective; // Defaults to true.
202 /// HasSingleParameterDotFile - True if the target has a single parameter
203 /// .file directive, this is true for ELF targets.
204 bool HasSingleParameterDotFile; // Defaults to true.
206 /// HasNoDeadStrip - True if this target supports the MachO .no_dead_strip
208 bool HasNoDeadStrip; // Defaults to false.
210 /// WeakRefDirective - This directive, if non-null, is used to declare a
211 /// global as being a weak undefined symbol.
212 const char *WeakRefDirective; // Defaults to NULL.
214 /// WeakDefDirective - This directive, if non-null, is used to declare a
215 /// global as being a weak defined symbol.
216 const char *WeakDefDirective; // Defaults to NULL.
218 /// LinkOnceDirective - This directive, if non-null is used to declare a
219 /// global as being a weak defined symbol. This is used on cygwin/mingw.
220 const char *LinkOnceDirective; // Defaults to NULL.
222 /// HiddenVisibilityAttr - This attribute, if not MCSA_Invalid, is used to
223 /// declare a symbol as having hidden visibility.
224 MCSymbolAttr HiddenVisibilityAttr; // Defaults to MCSA_Hidden.
226 /// ProtectedVisibilityAttr - This attribute, if not MCSA_Invalid, is used
227 /// to declare a symbol as having protected visibility.
228 MCSymbolAttr ProtectedVisibilityAttr; // Defaults to MCSA_Protected
230 //===--- Dwarf Emission Directives -----------------------------------===//
232 /// AbsoluteDebugSectionOffsets - True if we should emit abolute section
233 /// offsets for debug information.
234 bool AbsoluteDebugSectionOffsets; // Defaults to false.
236 /// AbsoluteEHSectionOffsets - True if we should emit abolute section
237 /// offsets for EH information. Defaults to false.
238 bool AbsoluteEHSectionOffsets;
240 /// HasLEB128 - True if target asm supports leb128 directives.
241 bool HasLEB128; // Defaults to false.
243 /// hasDotLocAndDotFile - True if target asm supports .loc and .file
244 /// directives for emitting debugging information.
245 bool HasDotLocAndDotFile; // Defaults to false.
247 /// SupportsDebugInformation - True if target supports emission of debugging
249 bool SupportsDebugInformation; // Defaults to false.
251 /// SupportsExceptionHandling - True if target supports exception handling.
252 ExceptionHandling::ExceptionsType ExceptionsType; // Defaults to None
254 /// RequiresFrameSection - true if the Dwarf2 output needs a frame section
255 bool DwarfRequiresFrameSection; // Defaults to true.
257 /// DwarfUsesInlineInfoSection - True if DwarfDebugInlineSection is used to
258 /// encode inline subroutine information.
259 bool DwarfUsesInlineInfoSection; // Defaults to false.
261 /// Is_EHSymbolPrivate - If set, the "_foo.eh" is made private so that it
262 /// doesn't show up in the symbol table of the object file.
263 bool Is_EHSymbolPrivate; // Defaults to true.
265 /// GlobalEHDirective - This is the directive used to make exception frame
266 /// tables globally visible.
267 const char *GlobalEHDirective; // Defaults to NULL.
269 /// SupportsWeakEmptyEHFrame - True if target assembler and linker will
270 /// handle a weak_definition of constant 0 for an omitted EH frame.
271 bool SupportsWeakOmittedEHFrame; // Defaults to true.
273 /// DwarfSectionOffsetDirective - Special section offset directive.
274 const char* DwarfSectionOffsetDirective; // Defaults to NULL
276 //===--- CBE Asm Translation Table -----------------------------------===//
278 const char *const *AsmTransCBE; // Defaults to empty
281 explicit MCAsmInfo();
282 virtual ~MCAsmInfo();
284 // FIXME: move these methods to DwarfPrinter when the JIT stops using them.
285 static unsigned getSLEB128Size(int Value);
286 static unsigned getULEB128Size(unsigned Value);
288 bool hasSubsectionsViaSymbols() const { return HasSubsectionsViaSymbols; }
290 // Data directive accessors.
292 const char *getData8bitsDirective(unsigned AS = 0) const {
293 return AS == 0 ? Data8bitsDirective : getDataASDirective(8, AS);
295 const char *getData16bitsDirective(unsigned AS = 0) const {
296 return AS == 0 ? Data16bitsDirective : getDataASDirective(16, AS);
298 const char *getData32bitsDirective(unsigned AS = 0) const {
299 return AS == 0 ? Data32bitsDirective : getDataASDirective(32, AS);
301 const char *getData64bitsDirective(unsigned AS = 0) const {
302 return AS == 0 ? Data64bitsDirective : getDataASDirective(64, AS);
305 /// getNonexecutableStackSection - Targets can implement this method to
306 /// specify a section to switch to if the translation unit doesn't have any
307 /// trampolines that require an executable stack.
308 virtual MCSection *getNonexecutableStackSection(MCContext &Ctx) const {
312 bool usesSunStyleELFSectionSwitchSyntax() const {
313 return SunStyleELFSectionSwitchSyntax;
316 bool usesELFSectionDirectiveForBSS() const {
317 return UsesELFSectionDirectiveForBSS;
322 bool hasMachoZeroFillDirective() const { return HasMachoZeroFillDirective; }
323 bool hasStaticCtorDtorReferenceInStaticMode() const {
324 return HasStaticCtorDtorReferenceInStaticMode;
326 bool needsSet() const {
329 unsigned getMaxInstLength() const {
330 return MaxInstLength;
332 const char *getPCSymbol() const {
335 char getSeparatorChar() const {
336 return SeparatorChar;
338 unsigned getCommentColumn() const {
339 return CommentColumn;
341 const char *getCommentString() const {
342 return CommentString;
344 const char *getGlobalPrefix() const {
347 const char *getPrivateGlobalPrefix() const {
348 return PrivateGlobalPrefix;
350 const char *getLinkerPrivateGlobalPrefix() const {
351 return LinkerPrivateGlobalPrefix;
353 const char *getInlineAsmStart() const {
354 return InlineAsmStart;
356 const char *getInlineAsmEnd() const {
359 unsigned getAssemblerDialect() const {
360 return AssemblerDialect;
362 bool doesAllowQuotesInName() const {
363 return AllowQuotesInName;
365 bool doesAllowNameToStartWithDigit() const {
366 return AllowNameToStartWithDigit;
368 const char *getZeroDirective() const {
369 return ZeroDirective;
371 const char *getAsciiDirective() const {
372 return AsciiDirective;
374 const char *getAscizDirective() const {
375 return AscizDirective;
377 const char *getJumpTableDirective(bool isPIC) const {
378 return isPIC ? PICJumpTableDirective : JumpTableDirective;
380 const char *getAlignDirective() const {
381 return AlignDirective;
383 bool getAlignmentIsInBytes() const {
384 return AlignmentIsInBytes;
386 unsigned getTextAlignFillValue() const {
387 return TextAlignFillValue;
389 const char *getGlobalDirective() const {
390 return GlobalDirective;
392 const char *getExternDirective() const {
393 return ExternDirective;
395 const char *getSetDirective() const {
398 bool hasLCOMMDirective() const { return HasLCOMMDirective; }
399 bool hasDotTypeDotSizeDirective() const {return HasDotTypeDotSizeDirective;}
400 bool hasSingleParameterDotFile() const { return HasSingleParameterDotFile; }
401 bool hasNoDeadStrip() const { return HasNoDeadStrip; }
402 const char *getWeakRefDirective() const { return WeakRefDirective; }
403 const char *getWeakDefDirective() const { return WeakDefDirective; }
404 const char *getLinkOnceDirective() const { return LinkOnceDirective; }
406 MCSymbolAttr getHiddenVisibilityAttr() const { return HiddenVisibilityAttr;}
407 MCSymbolAttr getProtectedVisibilityAttr() const {
408 return ProtectedVisibilityAttr;
410 bool isAbsoluteDebugSectionOffsets() const {
411 return AbsoluteDebugSectionOffsets;
413 bool isAbsoluteEHSectionOffsets() const {
414 return AbsoluteEHSectionOffsets;
416 bool hasLEB128() const {
419 bool hasDotLocAndDotFile() const {
420 return HasDotLocAndDotFile;
422 bool doesSupportDebugInformation() const {
423 return SupportsDebugInformation;
425 bool doesSupportExceptionHandling() const {
426 return ExceptionsType != ExceptionHandling::None;
428 ExceptionHandling::ExceptionsType getExceptionHandlingType() const {
429 return ExceptionsType;
431 bool doesDwarfRequireFrameSection() const {
432 return DwarfRequiresFrameSection;
434 bool doesDwarfUsesInlineInfoSection() const {
435 return DwarfUsesInlineInfoSection;
437 bool is_EHSymbolPrivate() const {
438 return Is_EHSymbolPrivate;
440 const char *getGlobalEHDirective() const {
441 return GlobalEHDirective;
443 bool getSupportsWeakOmittedEHFrame() const {
444 return SupportsWeakOmittedEHFrame;
446 const char *getDwarfSectionOffsetDirective() const {
447 return DwarfSectionOffsetDirective;
449 const char *const *getAsmCBE() const {