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 /// GPRel32Directive - if non-null, a directive that is used to emit a word
138 /// which should be relocated as a 32-bit GP-relative offset, e.g. .gpword
139 /// on Mips or .gprel32 on Alpha.
140 const char *GPRel32Directive; // Defaults to NULL.
142 /// getDataASDirective - Return the directive that should be used to emit
143 /// data of the specified size to the specified numeric address space.
144 virtual const char *getDataASDirective(unsigned Size, unsigned AS) const {
145 assert(AS != 0 && "Don't know the directives for default addr space");
149 /// SunStyleELFSectionSwitchSyntax - This is true if this target uses "Sun
150 /// Style" syntax for section switching ("#alloc,#write" etc) instead of the
151 /// normal ELF syntax (,"a,w") in .section directives.
152 bool SunStyleELFSectionSwitchSyntax; // Defaults to false.
154 /// UsesELFSectionDirectiveForBSS - This is true if this target uses ELF
155 /// '.section' directive before the '.bss' one. It's used for PPC/Linux
156 /// which doesn't support the '.bss' directive only.
157 bool UsesELFSectionDirectiveForBSS; // Defaults to false.
159 //===--- Alignment Information ----------------------------------------===//
161 /// AlignDirective - The directive used to emit round up to an alignment
164 const char *AlignDirective; // Defaults to "\t.align\t"
166 /// AlignmentIsInBytes - If this is true (the default) then the asmprinter
167 /// emits ".align N" directives, where N is the number of bytes to align to.
168 /// Otherwise, it emits ".align log2(N)", e.g. 3 to align to an 8 byte
170 bool AlignmentIsInBytes; // Defaults to true
172 /// TextAlignFillValue - If non-zero, this is used to fill the executable
173 /// space created as the result of a alignment directive.
174 unsigned TextAlignFillValue; // Defaults to 0
176 //===--- Global Variable Emission Directives --------------------------===//
178 /// GlobalDirective - This is the directive used to declare a global entity.
180 const char *GlobalDirective; // Defaults to NULL.
182 /// ExternDirective - This is the directive used to declare external
185 const char *ExternDirective; // Defaults to NULL.
187 /// SetDirective - This is the name of a directive that can be used to tell
188 /// the assembler to set the value of a variable to some expression.
189 const char *SetDirective; // Defaults to null.
191 /// HasLCOMMDirective - This is true if the target supports the .lcomm
193 bool HasLCOMMDirective; // Defaults to false.
195 /// HasDotTypeDotSizeDirective - True if the target has .type and .size
196 /// directives, this is true for most ELF targets.
197 bool HasDotTypeDotSizeDirective; // Defaults to true.
199 /// HasSingleParameterDotFile - True if the target has a single parameter
200 /// .file directive, this is true for ELF targets.
201 bool HasSingleParameterDotFile; // Defaults to true.
203 /// HasNoDeadStrip - True if this target supports the MachO .no_dead_strip
205 bool HasNoDeadStrip; // Defaults to false.
207 /// WeakRefDirective - This directive, if non-null, is used to declare a
208 /// global as being a weak undefined symbol.
209 const char *WeakRefDirective; // Defaults to NULL.
211 /// WeakDefDirective - This directive, if non-null, is used to declare a
212 /// global as being a weak defined symbol.
213 const char *WeakDefDirective; // Defaults to NULL.
215 /// LinkOnceDirective - This directive, if non-null is used to declare a
216 /// global as being a weak defined symbol. This is used on cygwin/mingw.
217 const char *LinkOnceDirective; // Defaults to NULL.
219 /// HiddenVisibilityAttr - This attribute, if not MCSA_Invalid, is used to
220 /// declare a symbol as having hidden visibility.
221 MCSymbolAttr HiddenVisibilityAttr; // Defaults to MCSA_Hidden.
223 /// ProtectedVisibilityAttr - This attribute, if not MCSA_Invalid, is used
224 /// to declare a symbol as having protected visibility.
225 MCSymbolAttr ProtectedVisibilityAttr; // Defaults to MCSA_Protected
227 //===--- Dwarf Emission Directives -----------------------------------===//
229 /// AbsoluteDebugSectionOffsets - True if we should emit abolute section
230 /// offsets for debug information.
231 bool AbsoluteDebugSectionOffsets; // Defaults to false.
233 /// AbsoluteEHSectionOffsets - True if we should emit abolute section
234 /// offsets for EH information. Defaults to false.
235 bool AbsoluteEHSectionOffsets;
237 /// HasLEB128 - True if target asm supports leb128 directives.
238 bool HasLEB128; // Defaults to false.
240 /// hasDotLocAndDotFile - True if target asm supports .loc and .file
241 /// directives for emitting debugging information.
242 bool HasDotLocAndDotFile; // Defaults to false.
244 /// SupportsDebugInformation - True if target supports emission of debugging
246 bool SupportsDebugInformation; // Defaults to false.
248 /// SupportsExceptionHandling - True if target supports exception handling.
249 ExceptionHandling::ExceptionsType ExceptionsType; // Defaults to None
251 /// RequiresFrameSection - true if the Dwarf2 output needs a frame section
252 bool DwarfRequiresFrameSection; // Defaults to true.
254 /// DwarfUsesInlineInfoSection - True if DwarfDebugInlineSection is used to
255 /// encode inline subroutine information.
256 bool DwarfUsesInlineInfoSection; // Defaults to false.
258 /// Is_EHSymbolPrivate - If set, the "_foo.eh" is made private so that it
259 /// doesn't show up in the symbol table of the object file.
260 bool Is_EHSymbolPrivate; // Defaults to true.
262 /// GlobalEHDirective - This is the directive used to make exception frame
263 /// tables globally visible.
264 const char *GlobalEHDirective; // Defaults to NULL.
266 /// SupportsWeakEmptyEHFrame - True if target assembler and linker will
267 /// handle a weak_definition of constant 0 for an omitted EH frame.
268 bool SupportsWeakOmittedEHFrame; // Defaults to true.
270 /// DwarfSectionOffsetDirective - Special section offset directive.
271 const char* DwarfSectionOffsetDirective; // Defaults to NULL
273 //===--- CBE Asm Translation Table -----------------------------------===//
275 const char *const *AsmTransCBE; // Defaults to empty
278 explicit MCAsmInfo();
279 virtual ~MCAsmInfo();
281 // FIXME: move these methods to DwarfPrinter when the JIT stops using them.
282 static unsigned getSLEB128Size(int Value);
283 static unsigned getULEB128Size(unsigned Value);
285 bool hasSubsectionsViaSymbols() const { return HasSubsectionsViaSymbols; }
287 // Data directive accessors.
289 const char *getData8bitsDirective(unsigned AS = 0) const {
290 return AS == 0 ? Data8bitsDirective : getDataASDirective(8, AS);
292 const char *getData16bitsDirective(unsigned AS = 0) const {
293 return AS == 0 ? Data16bitsDirective : getDataASDirective(16, AS);
295 const char *getData32bitsDirective(unsigned AS = 0) const {
296 return AS == 0 ? Data32bitsDirective : getDataASDirective(32, AS);
298 const char *getData64bitsDirective(unsigned AS = 0) const {
299 return AS == 0 ? Data64bitsDirective : getDataASDirective(64, AS);
301 const char *getGPRel32Directive() const { return GPRel32Directive; }
303 /// getNonexecutableStackSection - Targets can implement this method to
304 /// specify a section to switch to if the translation unit doesn't have any
305 /// trampolines that require an executable stack.
306 virtual MCSection *getNonexecutableStackSection(MCContext &Ctx) const {
310 bool usesSunStyleELFSectionSwitchSyntax() const {
311 return SunStyleELFSectionSwitchSyntax;
314 bool usesELFSectionDirectiveForBSS() const {
315 return UsesELFSectionDirectiveForBSS;
320 bool hasMachoZeroFillDirective() const { return HasMachoZeroFillDirective; }
321 bool hasStaticCtorDtorReferenceInStaticMode() const {
322 return HasStaticCtorDtorReferenceInStaticMode;
324 bool needsSet() const {
327 unsigned getMaxInstLength() const {
328 return MaxInstLength;
330 const char *getPCSymbol() const {
333 char getSeparatorChar() const {
334 return SeparatorChar;
336 unsigned getCommentColumn() const {
337 return CommentColumn;
339 const char *getCommentString() const {
340 return CommentString;
342 const char *getGlobalPrefix() const {
345 const char *getPrivateGlobalPrefix() const {
346 return PrivateGlobalPrefix;
348 const char *getLinkerPrivateGlobalPrefix() const {
349 return LinkerPrivateGlobalPrefix;
351 const char *getInlineAsmStart() const {
352 return InlineAsmStart;
354 const char *getInlineAsmEnd() const {
357 unsigned getAssemblerDialect() const {
358 return AssemblerDialect;
360 bool doesAllowQuotesInName() const {
361 return AllowQuotesInName;
363 bool doesAllowNameToStartWithDigit() const {
364 return AllowNameToStartWithDigit;
366 const char *getZeroDirective() const {
367 return ZeroDirective;
369 const char *getAsciiDirective() const {
370 return AsciiDirective;
372 const char *getAscizDirective() const {
373 return AscizDirective;
375 const char *getAlignDirective() const {
376 return AlignDirective;
378 bool getAlignmentIsInBytes() const {
379 return AlignmentIsInBytes;
381 unsigned getTextAlignFillValue() const {
382 return TextAlignFillValue;
384 const char *getGlobalDirective() const {
385 return GlobalDirective;
387 const char *getExternDirective() const {
388 return ExternDirective;
390 const char *getSetDirective() const {
393 bool hasLCOMMDirective() const { return HasLCOMMDirective; }
394 bool hasDotTypeDotSizeDirective() const {return HasDotTypeDotSizeDirective;}
395 bool hasSingleParameterDotFile() const { return HasSingleParameterDotFile; }
396 bool hasNoDeadStrip() const { return HasNoDeadStrip; }
397 const char *getWeakRefDirective() const { return WeakRefDirective; }
398 const char *getWeakDefDirective() const { return WeakDefDirective; }
399 const char *getLinkOnceDirective() const { return LinkOnceDirective; }
401 MCSymbolAttr getHiddenVisibilityAttr() const { return HiddenVisibilityAttr;}
402 MCSymbolAttr getProtectedVisibilityAttr() const {
403 return ProtectedVisibilityAttr;
405 bool isAbsoluteDebugSectionOffsets() const {
406 return AbsoluteDebugSectionOffsets;
408 bool isAbsoluteEHSectionOffsets() const {
409 return AbsoluteEHSectionOffsets;
411 bool hasLEB128() const {
414 bool hasDotLocAndDotFile() const {
415 return HasDotLocAndDotFile;
417 bool doesSupportDebugInformation() const {
418 return SupportsDebugInformation;
420 bool doesSupportExceptionHandling() const {
421 return ExceptionsType != ExceptionHandling::None;
423 ExceptionHandling::ExceptionsType getExceptionHandlingType() const {
424 return ExceptionsType;
426 bool doesDwarfRequireFrameSection() const {
427 return DwarfRequiresFrameSection;
429 bool doesDwarfUsesInlineInfoSection() const {
430 return DwarfUsesInlineInfoSection;
432 bool is_EHSymbolPrivate() const {
433 return Is_EHSymbolPrivate;
435 const char *getGlobalEHDirective() const {
436 return GlobalEHDirective;
438 bool getSupportsWeakOmittedEHFrame() const {
439 return SupportsWeakOmittedEHFrame;
441 const char *getDwarfSectionOffsetDirective() const {
442 return DwarfSectionOffsetDirective;
444 const char *const *getAsmCBE() const {