1//===--- TargetInfo.h - Expose information about the target -----*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9///
10/// \file
11/// \brief Defines the clang::TargetInfo interface.
12///
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_CLANG_BASIC_TARGETINFO_H
16#define LLVM_CLANG_BASIC_TARGETINFO_H
17
18#include "clang/Basic/AddressSpaces.h"
19#include "clang/Basic/TargetCXXABI.h"
20#include "clang/Basic/LLVM.h"
21#include "clang/Basic/Specifiers.h"
22#include "clang/Basic/TargetOptions.h"
23#include "clang/Basic/VersionTuple.h"
24#include "llvm/ADT/IntrusiveRefCntPtr.h"
25#include "llvm/ADT/StringMap.h"
26#include "llvm/ADT/StringRef.h"
27#include "llvm/ADT/StringSwitch.h"
28#include "llvm/ADT/Triple.h"
29#include "llvm/Support/DataTypes.h"
30#include <cassert>
31#include <string>
32#include <vector>
33
34namespace llvm {
35struct fltSemantics;
36}
37
38namespace clang {
39class DiagnosticsEngine;
40class LangOptions;
41class MacroBuilder;
42class SourceLocation;
43class SourceManager;
44
45namespace Builtin { struct Info; }
46
47/// \brief Exposes information about the current target.
48///
49class TargetInfo : public RefCountedBase<TargetInfo> {
50  IntrusiveRefCntPtr<TargetOptions> TargetOpts;
51  llvm::Triple Triple;
52protected:
53  // Target values set by the ctor of the actual target implementation.  Default
54  // values are specified by the TargetInfo constructor.
55  bool BigEndian;
56  bool TLSSupported;
57  bool NoAsmVariants;  // True if {|} are normal characters.
58  unsigned char PointerWidth, PointerAlign;
59  unsigned char BoolWidth, BoolAlign;
60  unsigned char IntWidth, IntAlign;
61  unsigned char HalfWidth, HalfAlign;
62  unsigned char FloatWidth, FloatAlign;
63  unsigned char DoubleWidth, DoubleAlign;
64  unsigned char LongDoubleWidth, LongDoubleAlign;
65  unsigned char LargeArrayMinWidth, LargeArrayAlign;
66  unsigned char LongWidth, LongAlign;
67  unsigned char LongLongWidth, LongLongAlign;
68  unsigned char SuitableAlign;
69  unsigned char MaxAtomicPromoteWidth, MaxAtomicInlineWidth;
70  unsigned short MaxVectorAlign;
71  const char *DescriptionString;
72  const char *UserLabelPrefix;
73  const char *MCountName;
74  const llvm::fltSemantics *HalfFormat, *FloatFormat, *DoubleFormat,
75    *LongDoubleFormat;
76  unsigned char RegParmMax, SSERegParmMax;
77  TargetCXXABI TheCXXABI;
78  const LangAS::Map *AddrSpaceMap;
79
80  mutable StringRef PlatformName;
81  mutable VersionTuple PlatformMinVersion;
82
83  unsigned HasAlignMac68kSupport : 1;
84  unsigned RealTypeUsesObjCFPRet : 3;
85  unsigned ComplexLongDoubleUsesFP2Ret : 1;
86
87  // TargetInfo Constructor.  Default initializes all fields.
88  TargetInfo(const std::string &T);
89
90public:
91  /// \brief Construct a target for the given options.
92  ///
93  /// \param Opts - The options to use to initialize the target. The target may
94  /// modify the options to canonicalize the target feature information to match
95  /// what the backend expects.
96  static TargetInfo* CreateTargetInfo(DiagnosticsEngine &Diags,
97                                      TargetOptions *Opts);
98
99  virtual ~TargetInfo();
100
101  /// \brief Retrieve the target options.
102  TargetOptions &getTargetOpts() const {
103    assert(TargetOpts && "Missing target options");
104    return *TargetOpts;
105  }
106
107  void setTargetOpts(TargetOptions *TargetOpts) {
108    this->TargetOpts = TargetOpts;
109  }
110
111  ///===---- Target Data Type Query Methods -------------------------------===//
112  enum IntType {
113    NoInt = 0,
114    SignedShort,
115    UnsignedShort,
116    SignedInt,
117    UnsignedInt,
118    SignedLong,
119    UnsignedLong,
120    SignedLongLong,
121    UnsignedLongLong
122  };
123
124  enum RealType {
125    Float = 0,
126    Double,
127    LongDouble
128  };
129
130  /// \brief The different kinds of __builtin_va_list types defined by
131  /// the target implementation.
132  enum BuiltinVaListKind {
133    /// typedef char* __builtin_va_list;
134    CharPtrBuiltinVaList = 0,
135
136    /// typedef void* __builtin_va_list;
137    VoidPtrBuiltinVaList,
138
139    /// __builtin_va_list as defind by the AArch64 ABI
140    /// http://infocenter.arm.com/help/topic/com.arm.doc.ihi0055a/IHI0055A_aapcs64.pdf
141    AArch64ABIBuiltinVaList,
142
143    /// __builtin_va_list as defined by the PNaCl ABI:
144    /// http://www.chromium.org/nativeclient/pnacl/bitcode-abi#TOC-Machine-Types
145    PNaClABIBuiltinVaList,
146
147    /// __builtin_va_list as defined by the Power ABI:
148    /// https://www.power.org
149    ///        /resources/downloads/Power-Arch-32-bit-ABI-supp-1.0-Embedded.pdf
150    PowerABIBuiltinVaList,
151
152    /// __builtin_va_list as defined by the x86-64 ABI:
153    /// http://www.x86-64.org/documentation/abi.pdf
154    X86_64ABIBuiltinVaList,
155
156    /// __builtin_va_list as defined by ARM AAPCS ABI
157    /// http://infocenter.arm.com
158    //        /help/topic/com.arm.doc.ihi0042d/IHI0042D_aapcs.pdf
159    AAPCSABIBuiltinVaList
160  };
161
162protected:
163  IntType SizeType, IntMaxType, UIntMaxType, PtrDiffType, IntPtrType, WCharType,
164          WIntType, Char16Type, Char32Type, Int64Type, SigAtomicType,
165          ProcessIDType;
166
167  /// \brief Whether Objective-C's built-in boolean type should be signed char.
168  ///
169  /// Otherwise, when this flag is not set, the normal built-in boolean type is
170  /// used.
171  unsigned UseSignedCharForObjCBool : 1;
172
173  /// Control whether the alignment of bit-field types is respected when laying
174  /// out structures. If true, then the alignment of the bit-field type will be
175  /// used to (a) impact the alignment of the containing structure, and (b)
176  /// ensure that the individual bit-field will not straddle an alignment
177  /// boundary.
178  unsigned UseBitFieldTypeAlignment : 1;
179
180  /// \brief Whether zero length bitfields (e.g., int : 0;) force alignment of
181  /// the next bitfield.
182  ///
183  /// If the alignment of the zero length bitfield is greater than the member
184  /// that follows it, `bar', `bar' will be aligned as the type of the
185  /// zero-length bitfield.
186  unsigned UseZeroLengthBitfieldAlignment : 1;
187
188  /// If non-zero, specifies a fixed alignment value for bitfields that follow
189  /// zero length bitfield, regardless of the zero length bitfield type.
190  unsigned ZeroLengthBitfieldBoundary;
191
192public:
193  IntType getSizeType() const { return SizeType; }
194  IntType getIntMaxType() const { return IntMaxType; }
195  IntType getUIntMaxType() const { return UIntMaxType; }
196  IntType getPtrDiffType(unsigned AddrSpace) const {
197    return AddrSpace == 0 ? PtrDiffType : getPtrDiffTypeV(AddrSpace);
198  }
199  IntType getIntPtrType() const { return IntPtrType; }
200  IntType getWCharType() const { return WCharType; }
201  IntType getWIntType() const { return WIntType; }
202  IntType getChar16Type() const { return Char16Type; }
203  IntType getChar32Type() const { return Char32Type; }
204  IntType getInt64Type() const { return Int64Type; }
205  IntType getSigAtomicType() const { return SigAtomicType; }
206  IntType getProcessIDType() const { return ProcessIDType; }
207
208  /// \brief Return the width (in bits) of the specified integer type enum.
209  ///
210  /// For example, SignedInt -> getIntWidth().
211  unsigned getTypeWidth(IntType T) const;
212
213  /// \brief Return the alignment (in bits) of the specified integer type enum.
214  ///
215  /// For example, SignedInt -> getIntAlign().
216  unsigned getTypeAlign(IntType T) const;
217
218  /// \brief Returns true if the type is signed; false otherwise.
219  static bool isTypeSigned(IntType T);
220
221  /// \brief Return the width of pointers on this target, for the
222  /// specified address space.
223  uint64_t getPointerWidth(unsigned AddrSpace) const {
224    return AddrSpace == 0 ? PointerWidth : getPointerWidthV(AddrSpace);
225  }
226  uint64_t getPointerAlign(unsigned AddrSpace) const {
227    return AddrSpace == 0 ? PointerAlign : getPointerAlignV(AddrSpace);
228  }
229
230  /// \brief Return the size of '_Bool' and C++ 'bool' for this target, in bits.
231  unsigned getBoolWidth() const { return BoolWidth; }
232
233  /// \brief Return the alignment of '_Bool' and C++ 'bool' for this target.
234  unsigned getBoolAlign() const { return BoolAlign; }
235
236  unsigned getCharWidth() const { return 8; } // FIXME
237  unsigned getCharAlign() const { return 8; } // FIXME
238
239  /// \brief Return the size of 'signed short' and 'unsigned short' for this
240  /// target, in bits.
241  unsigned getShortWidth() const { return 16; } // FIXME
242
243  /// \brief Return the alignment of 'signed short' and 'unsigned short' for
244  /// this target.
245  unsigned getShortAlign() const { return 16; } // FIXME
246
247  /// getIntWidth/Align - Return the size of 'signed int' and 'unsigned int' for
248  /// this target, in bits.
249  unsigned getIntWidth() const { return IntWidth; }
250  unsigned getIntAlign() const { return IntAlign; }
251
252  /// getLongWidth/Align - Return the size of 'signed long' and 'unsigned long'
253  /// for this target, in bits.
254  unsigned getLongWidth() const { return LongWidth; }
255  unsigned getLongAlign() const { return LongAlign; }
256
257  /// getLongLongWidth/Align - Return the size of 'signed long long' and
258  /// 'unsigned long long' for this target, in bits.
259  unsigned getLongLongWidth() const { return LongLongWidth; }
260  unsigned getLongLongAlign() const { return LongLongAlign; }
261
262  /// \brief Determine whether the __int128 type is supported on this target.
263  bool hasInt128Type() const { return getPointerWidth(0) >= 64; } // FIXME
264
265  /// \brief Return the alignment that is suitable for storing any
266  /// object with a fundamental alignment requirement.
267  unsigned getSuitableAlign() const { return SuitableAlign; }
268
269  /// getWCharWidth/Align - Return the size of 'wchar_t' for this target, in
270  /// bits.
271  unsigned getWCharWidth() const { return getTypeWidth(WCharType); }
272  unsigned getWCharAlign() const { return getTypeAlign(WCharType); }
273
274  /// getChar16Width/Align - Return the size of 'char16_t' for this target, in
275  /// bits.
276  unsigned getChar16Width() const { return getTypeWidth(Char16Type); }
277  unsigned getChar16Align() const { return getTypeAlign(Char16Type); }
278
279  /// getChar32Width/Align - Return the size of 'char32_t' for this target, in
280  /// bits.
281  unsigned getChar32Width() const { return getTypeWidth(Char32Type); }
282  unsigned getChar32Align() const { return getTypeAlign(Char32Type); }
283
284  /// getHalfWidth/Align/Format - Return the size/align/format of 'half'.
285  unsigned getHalfWidth() const { return HalfWidth; }
286  unsigned getHalfAlign() const { return HalfAlign; }
287  const llvm::fltSemantics &getHalfFormat() const { return *HalfFormat; }
288
289  /// getFloatWidth/Align/Format - Return the size/align/format of 'float'.
290  unsigned getFloatWidth() const { return FloatWidth; }
291  unsigned getFloatAlign() const { return FloatAlign; }
292  const llvm::fltSemantics &getFloatFormat() const { return *FloatFormat; }
293
294  /// getDoubleWidth/Align/Format - Return the size/align/format of 'double'.
295  unsigned getDoubleWidth() const { return DoubleWidth; }
296  unsigned getDoubleAlign() const { return DoubleAlign; }
297  const llvm::fltSemantics &getDoubleFormat() const { return *DoubleFormat; }
298
299  /// getLongDoubleWidth/Align/Format - Return the size/align/format of 'long
300  /// double'.
301  unsigned getLongDoubleWidth() const { return LongDoubleWidth; }
302  unsigned getLongDoubleAlign() const { return LongDoubleAlign; }
303  const llvm::fltSemantics &getLongDoubleFormat() const {
304    return *LongDoubleFormat;
305  }
306
307  /// \brief Return the value for the C99 FLT_EVAL_METHOD macro.
308  virtual unsigned getFloatEvalMethod() const { return 0; }
309
310  // getLargeArrayMinWidth/Align - Return the minimum array size that is
311  // 'large' and its alignment.
312  unsigned getLargeArrayMinWidth() const { return LargeArrayMinWidth; }
313  unsigned getLargeArrayAlign() const { return LargeArrayAlign; }
314
315  /// \brief Return the maximum width lock-free atomic operation which will
316  /// ever be supported for the given target
317  unsigned getMaxAtomicPromoteWidth() const { return MaxAtomicPromoteWidth; }
318  /// \brief Return the maximum width lock-free atomic operation which can be
319  /// inlined given the supported features of the given target.
320  unsigned getMaxAtomicInlineWidth() const { return MaxAtomicInlineWidth; }
321
322  /// \brief Return the maximum vector alignment supported for the given target.
323  unsigned getMaxVectorAlign() const { return MaxVectorAlign; }
324
325  /// \brief Return the size of intmax_t and uintmax_t for this target, in bits.
326  unsigned getIntMaxTWidth() const {
327    return getTypeWidth(IntMaxType);
328  }
329
330  // Return the size of unwind_word for this target.
331  unsigned getUnwindWordWidth() const { return getPointerWidth(0); }
332
333  /// \brief Return the "preferred" register width on this target.
334  uint64_t getRegisterWidth() const {
335    // Currently we assume the register width on the target matches the pointer
336    // width, we can introduce a new variable for this if/when some target wants
337    // it.
338    return LongWidth;
339  }
340
341  /// \brief Returns the default value of the __USER_LABEL_PREFIX__ macro,
342  /// which is the prefix given to user symbols by default.
343  ///
344  /// On most platforms this is "_", but it is "" on some, and "." on others.
345  const char *getUserLabelPrefix() const {
346    return UserLabelPrefix;
347  }
348
349  /// \brief Returns the name of the mcount instrumentation function.
350  const char *getMCountName() const {
351    return MCountName;
352  }
353
354  /// \brief Check if the Objective-C built-in boolean type should be signed
355  /// char.
356  ///
357  /// Otherwise, if this returns false, the normal built-in boolean type
358  /// should also be used for Objective-C.
359  bool useSignedCharForObjCBool() const {
360    return UseSignedCharForObjCBool;
361  }
362  void noSignedCharForObjCBool() {
363    UseSignedCharForObjCBool = false;
364  }
365
366  /// \brief Check whether the alignment of bit-field types is respected
367  /// when laying out structures.
368  bool useBitFieldTypeAlignment() const {
369    return UseBitFieldTypeAlignment;
370  }
371
372  /// \brief Check whether zero length bitfields should force alignment of
373  /// the next member.
374  bool useZeroLengthBitfieldAlignment() const {
375    return UseZeroLengthBitfieldAlignment;
376  }
377
378  /// \brief Get the fixed alignment value in bits for a member that follows
379  /// a zero length bitfield.
380  unsigned getZeroLengthBitfieldBoundary() const {
381    return ZeroLengthBitfieldBoundary;
382  }
383
384  /// \brief Check whether this target support '\#pragma options align=mac68k'.
385  bool hasAlignMac68kSupport() const {
386    return HasAlignMac68kSupport;
387  }
388
389  /// \brief Return the user string for the specified integer type enum.
390  ///
391  /// For example, SignedShort -> "short".
392  static const char *getTypeName(IntType T);
393
394  /// \brief Return the constant suffix for the specified integer type enum.
395  ///
396  /// For example, SignedLong -> "L".
397  static const char *getTypeConstantSuffix(IntType T);
398
399  /// \brief Check whether the given real type should use the "fpret" flavor of
400  /// Objective-C message passing on this target.
401  bool useObjCFPRetForRealType(RealType T) const {
402    return RealTypeUsesObjCFPRet & (1 << T);
403  }
404
405  /// \brief Check whether _Complex long double should use the "fp2ret" flavor
406  /// of Objective-C message passing on this target.
407  bool useObjCFP2RetForComplexLongDouble() const {
408    return ComplexLongDoubleUsesFP2Ret;
409  }
410
411  ///===---- Other target property query methods --------------------------===//
412
413  /// \brief Appends the target-specific \#define values for this
414  /// target set to the specified buffer.
415  virtual void getTargetDefines(const LangOptions &Opts,
416                                MacroBuilder &Builder) const = 0;
417
418
419  /// Return information about target-specific builtins for
420  /// the current primary target, and info about which builtins are non-portable
421  /// across the current set of primary and secondary targets.
422  virtual void getTargetBuiltins(const Builtin::Info *&Records,
423                                 unsigned &NumRecords) const = 0;
424
425  /// The __builtin_clz* and __builtin_ctz* built-in
426  /// functions are specified to have undefined results for zero inputs, but
427  /// on targets that support these operations in a way that provides
428  /// well-defined results for zero without loss of performance, it is a good
429  /// idea to avoid optimizing based on that undef behavior.
430  virtual bool isCLZForZeroUndef() const { return true; }
431
432  /// \brief Returns the kind of __builtin_va_list type that should be used
433  /// with this target.
434  virtual BuiltinVaListKind getBuiltinVaListKind() const = 0;
435
436  /// \brief Returns whether the passed in string is a valid clobber in an
437  /// inline asm statement.
438  ///
439  /// This is used by Sema.
440  bool isValidClobber(StringRef Name) const;
441
442  /// \brief Returns whether the passed in string is a valid register name
443  /// according to GCC.
444  ///
445  /// This is used by Sema for inline asm statements.
446  bool isValidGCCRegisterName(StringRef Name) const;
447
448  /// \brief Returns the "normalized" GCC register name.
449  ///
450  /// For example, on x86 it will return "ax" when "eax" is passed in.
451  StringRef getNormalizedGCCRegisterName(StringRef Name) const;
452
453  struct ConstraintInfo {
454    enum {
455      CI_None = 0x00,
456      CI_AllowsMemory = 0x01,
457      CI_AllowsRegister = 0x02,
458      CI_ReadWrite = 0x04,       // "+r" output constraint (read and write).
459      CI_HasMatchingInput = 0x08 // This output operand has a matching input.
460    };
461    unsigned Flags;
462    int TiedOperand;
463
464    std::string ConstraintStr;  // constraint: "=rm"
465    std::string Name;           // Operand name: [foo] with no []'s.
466  public:
467    ConstraintInfo(StringRef ConstraintStr, StringRef Name)
468      : Flags(0), TiedOperand(-1), ConstraintStr(ConstraintStr.str()),
469      Name(Name.str()) {}
470
471    const std::string &getConstraintStr() const { return ConstraintStr; }
472    const std::string &getName() const { return Name; }
473    bool isReadWrite() const { return (Flags & CI_ReadWrite) != 0; }
474    bool allowsRegister() const { return (Flags & CI_AllowsRegister) != 0; }
475    bool allowsMemory() const { return (Flags & CI_AllowsMemory) != 0; }
476
477    /// \brief Return true if this output operand has a matching
478    /// (tied) input operand.
479    bool hasMatchingInput() const { return (Flags & CI_HasMatchingInput) != 0; }
480
481    /// \brief Return true if this input operand is a matching
482    /// constraint that ties it to an output operand.
483    ///
484    /// If this returns true then getTiedOperand will indicate which output
485    /// operand this is tied to.
486    bool hasTiedOperand() const { return TiedOperand != -1; }
487    unsigned getTiedOperand() const {
488      assert(hasTiedOperand() && "Has no tied operand!");
489      return (unsigned)TiedOperand;
490    }
491
492    void setIsReadWrite() { Flags |= CI_ReadWrite; }
493    void setAllowsMemory() { Flags |= CI_AllowsMemory; }
494    void setAllowsRegister() { Flags |= CI_AllowsRegister; }
495    void setHasMatchingInput() { Flags |= CI_HasMatchingInput; }
496
497    /// \brief Indicate that this is an input operand that is tied to
498    /// the specified output operand.
499    ///
500    /// Copy over the various constraint information from the output.
501    void setTiedOperand(unsigned N, ConstraintInfo &Output) {
502      Output.setHasMatchingInput();
503      Flags = Output.Flags;
504      TiedOperand = N;
505      // Don't copy Name or constraint string.
506    }
507  };
508
509  // validateOutputConstraint, validateInputConstraint - Checks that
510  // a constraint is valid and provides information about it.
511  // FIXME: These should return a real error instead of just true/false.
512  bool validateOutputConstraint(ConstraintInfo &Info) const;
513  bool validateInputConstraint(ConstraintInfo *OutputConstraints,
514                               unsigned NumOutputs,
515                               ConstraintInfo &info) const;
516  virtual bool validateInputSize(StringRef /*Constraint*/,
517                                 unsigned /*Size*/) const {
518    return true;
519  }
520  virtual bool validateConstraintModifier(StringRef /*Constraint*/,
521                                          const char /*Modifier*/,
522                                          unsigned /*Size*/) const {
523    return true;
524  }
525  bool resolveSymbolicName(const char *&Name,
526                           ConstraintInfo *OutputConstraints,
527                           unsigned NumOutputs, unsigned &Index) const;
528
529  // Constraint parm will be left pointing at the last character of
530  // the constraint.  In practice, it won't be changed unless the
531  // constraint is longer than one character.
532  virtual std::string convertConstraint(const char *&Constraint) const {
533    // 'p' defaults to 'r', but can be overridden by targets.
534    if (*Constraint == 'p')
535      return std::string("r");
536    return std::string(1, *Constraint);
537  }
538
539  /// \brief Returns a string of target-specific clobbers, in LLVM format.
540  virtual const char *getClobbers() const = 0;
541
542
543  /// \brief Returns the target triple of the primary target.
544  const llvm::Triple &getTriple() const {
545    return Triple;
546  }
547
548  const char *getTargetDescription() const {
549    return DescriptionString;
550  }
551
552  struct GCCRegAlias {
553    const char * const Aliases[5];
554    const char * const Register;
555  };
556
557  struct AddlRegName {
558    const char * const Names[5];
559    const unsigned RegNum;
560  };
561
562  /// \brief Does this target support "protected" visibility?
563  ///
564  /// Any target which dynamic libraries will naturally support
565  /// something like "default" (meaning that the symbol is visible
566  /// outside this shared object) and "hidden" (meaning that it isn't)
567  /// visibilities, but "protected" is really an ELF-specific concept
568  /// with weird semantics designed around the convenience of dynamic
569  /// linker implementations.  Which is not to suggest that there's
570  /// consistent target-independent semantics for "default" visibility
571  /// either; the entire thing is pretty badly mangled.
572  virtual bool hasProtectedVisibility() const { return true; }
573
574  virtual bool useGlobalsForAutomaticVariables() const { return false; }
575
576  /// \brief Return the section to use for CFString literals, or 0 if no
577  /// special section is used.
578  virtual const char *getCFStringSection() const {
579    return "__DATA,__cfstring";
580  }
581
582  /// \brief Return the section to use for NSString literals, or 0 if no
583  /// special section is used.
584  virtual const char *getNSStringSection() const {
585    return "__OBJC,__cstring_object,regular,no_dead_strip";
586  }
587
588  /// \brief Return the section to use for NSString literals, or 0 if no
589  /// special section is used (NonFragile ABI).
590  virtual const char *getNSStringNonFragileABISection() const {
591    return "__DATA, __objc_stringobj, regular, no_dead_strip";
592  }
593
594  /// \brief An optional hook that targets can implement to perform semantic
595  /// checking on attribute((section("foo"))) specifiers.
596  ///
597  /// In this case, "foo" is passed in to be checked.  If the section
598  /// specifier is invalid, the backend should return a non-empty string
599  /// that indicates the problem.
600  ///
601  /// This hook is a simple quality of implementation feature to catch errors
602  /// and give good diagnostics in cases when the assembler or code generator
603  /// would otherwise reject the section specifier.
604  ///
605  virtual std::string isValidSectionSpecifier(StringRef SR) const {
606    return "";
607  }
608
609  /// \brief Set forced language options.
610  ///
611  /// Apply changes to the target information with respect to certain
612  /// language options which change the target configuration.
613  virtual void setForcedLangOptions(LangOptions &Opts);
614
615  /// \brief Get the default set of target features for the CPU;
616  /// this should include all legal feature strings on the target.
617  virtual void getDefaultFeatures(llvm::StringMap<bool> &Features) const {
618  }
619
620  /// \brief Get the ABI currently in use.
621  virtual const char *getABI() const {
622    return "";
623  }
624
625  /// \brief Get the C++ ABI currently in use.
626  TargetCXXABI getCXXABI() const {
627    return TheCXXABI;
628  }
629
630  /// \brief Target the specified CPU.
631  ///
632  /// \return  False on error (invalid CPU name).
633  virtual bool setCPU(const std::string &Name) {
634    return false;
635  }
636
637  /// \brief Use the specified ABI.
638  ///
639  /// \return False on error (invalid ABI name).
640  virtual bool setABI(const std::string &Name) {
641    return false;
642  }
643
644  /// \brief Use this specified C++ ABI.
645  ///
646  /// \return False on error (invalid C++ ABI name).
647  bool setCXXABI(llvm::StringRef name) {
648    TargetCXXABI ABI;
649    if (!ABI.tryParse(name)) return false;
650    return setCXXABI(ABI);
651  }
652
653  /// \brief Set the C++ ABI to be used by this implementation.
654  ///
655  /// \return False on error (ABI not valid on this target)
656  virtual bool setCXXABI(TargetCXXABI ABI) {
657    TheCXXABI = ABI;
658    return true;
659  }
660
661  /// \brief Enable or disable a specific target feature;
662  /// the feature name must be valid.
663  ///
664  /// \return False on error (invalid feature name).
665  virtual bool setFeatureEnabled(llvm::StringMap<bool> &Features,
666                                 StringRef Name,
667                                 bool Enabled) const {
668    return false;
669  }
670
671  /// \brief Perform initialization based on the user configured
672  /// set of features (e.g., +sse4).
673  ///
674  /// The list is guaranteed to have at most one entry per feature.
675  ///
676  /// The target may modify the features list, to change which options are
677  /// passed onwards to the backend.
678  virtual void HandleTargetFeatures(std::vector<std::string> &Features) {
679  }
680
681  /// \brief Determine whether the given target has the given feature.
682  virtual bool hasFeature(StringRef Feature) const {
683    return false;
684  }
685
686  // \brief Returns maximal number of args passed in registers.
687  unsigned getRegParmMax() const {
688    assert(RegParmMax < 7 && "RegParmMax value is larger than AST can handle");
689    return RegParmMax;
690  }
691
692  /// \brief Whether the target supports thread-local storage.
693  bool isTLSSupported() const {
694    return TLSSupported;
695  }
696
697  /// \brief Return true if {|} are normal characters in the asm string.
698  ///
699  /// If this returns false (the default), then {abc|xyz} is syntax
700  /// that says that when compiling for asm variant #0, "abc" should be
701  /// generated, but when compiling for asm variant #1, "xyz" should be
702  /// generated.
703  bool hasNoAsmVariants() const {
704    return NoAsmVariants;
705  }
706
707  /// \brief Return the register number that __builtin_eh_return_regno would
708  /// return with the specified argument.
709  virtual int getEHDataRegisterNumber(unsigned RegNo) const {
710    return -1;
711  }
712
713  /// \brief Return the section to use for C++ static initialization functions.
714  virtual const char *getStaticInitSectionSpecifier() const {
715    return 0;
716  }
717
718  const LangAS::Map &getAddressSpaceMap() const {
719    return *AddrSpaceMap;
720  }
721
722  /// \brief Retrieve the name of the platform as it is used in the
723  /// availability attribute.
724  StringRef getPlatformName() const { return PlatformName; }
725
726  /// \brief Retrieve the minimum desired version of the platform, to
727  /// which the program should be compiled.
728  VersionTuple getPlatformMinVersion() const { return PlatformMinVersion; }
729
730  bool isBigEndian() const { return BigEndian; }
731
732  enum CallingConvMethodType {
733    CCMT_Unknown,
734    CCMT_Member,
735    CCMT_NonMember
736  };
737
738  /// \brief Gets the default calling convention for the given target and
739  /// declaration context.
740  virtual CallingConv getDefaultCallingConv(CallingConvMethodType MT) const {
741    // Not all targets will specify an explicit calling convention that we can
742    // express.  This will always do the right thing, even though it's not
743    // an explicit calling convention.
744    return CC_C;
745  }
746
747  enum CallingConvCheckResult {
748    CCCR_OK,
749    CCCR_Warning
750  };
751
752  /// \brief Determines whether a given calling convention is valid for the
753  /// target. A calling convention can either be accepted, produce a warning
754  /// and be substituted with the default calling convention, or (someday)
755  /// produce an error (such as using thiscall on a non-instance function).
756  virtual CallingConvCheckResult checkCallingConvention(CallingConv CC) const {
757    switch (CC) {
758      default:
759        return CCCR_Warning;
760      case CC_C:
761      case CC_Default:
762        return CCCR_OK;
763    }
764  }
765
766protected:
767  virtual uint64_t getPointerWidthV(unsigned AddrSpace) const {
768    return PointerWidth;
769  }
770  virtual uint64_t getPointerAlignV(unsigned AddrSpace) const {
771    return PointerAlign;
772  }
773  virtual enum IntType getPtrDiffTypeV(unsigned AddrSpace) const {
774    return PtrDiffType;
775  }
776  virtual void getGCCRegNames(const char * const *&Names,
777                              unsigned &NumNames) const = 0;
778  virtual void getGCCRegAliases(const GCCRegAlias *&Aliases,
779                                unsigned &NumAliases) const = 0;
780  virtual void getGCCAddlRegNames(const AddlRegName *&Addl,
781				  unsigned &NumAddl) const {
782    Addl = 0;
783    NumAddl = 0;
784  }
785  virtual bool validateAsmConstraint(const char *&Name,
786                                     TargetInfo::ConstraintInfo &info) const= 0;
787};
788
789}  // end namespace clang
790
791#endif
792