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/LLVM.h"
19#include "llvm/ADT/IntrusiveRefCntPtr.h"
20#include "llvm/ADT/StringMap.h"
21#include "llvm/ADT/StringRef.h"
22#include "llvm/ADT/StringSwitch.h"
23#include "llvm/ADT/Triple.h"
24#include "llvm/Support/DataTypes.h"
25#include "clang/Basic/AddressSpaces.h"
26#include "clang/Basic/VersionTuple.h"
27#include <cassert>
28#include <vector>
29#include <string>
30
31namespace llvm {
32struct fltSemantics;
33}
34
35namespace clang {
36class DiagnosticsEngine;
37class LangOptions;
38class MacroBuilder;
39class SourceLocation;
40class SourceManager;
41class TargetOptions;
42
43namespace Builtin { struct Info; }
44
45/// \brief The types of C++ ABIs for which we can generate code.
46enum TargetCXXABI {
47  /// The generic ("Itanium") C++ ABI, documented at:
48  ///   http://www.codesourcery.com/public/cxx-abi/
49  CXXABI_Itanium,
50
51  /// The ARM C++ ABI, based largely on the Itanium ABI but with
52  /// significant differences.
53  ///    http://infocenter.arm.com
54  ///                    /help/topic/com.arm.doc.ihi0041c/IHI0041C_cppabi.pdf
55  CXXABI_ARM,
56
57  /// The Visual Studio ABI.  Only scattered official documentation exists.
58  CXXABI_Microsoft
59};
60
61/// \brief Exposes information about the current target.
62///
63class TargetInfo : public RefCountedBase<TargetInfo> {
64  llvm::Triple Triple;
65protected:
66  // Target values set by the ctor of the actual target implementation.  Default
67  // values are specified by the TargetInfo constructor.
68  bool BigEndian;
69  bool TLSSupported;
70  bool NoAsmVariants;  // True if {|} are normal characters.
71  unsigned char PointerWidth, PointerAlign;
72  unsigned char BoolWidth, BoolAlign;
73  unsigned char IntWidth, IntAlign;
74  unsigned char HalfWidth, HalfAlign;
75  unsigned char FloatWidth, FloatAlign;
76  unsigned char DoubleWidth, DoubleAlign;
77  unsigned char LongDoubleWidth, LongDoubleAlign;
78  unsigned char LargeArrayMinWidth, LargeArrayAlign;
79  unsigned char LongWidth, LongAlign;
80  unsigned char LongLongWidth, LongLongAlign;
81  unsigned char SuitableAlign;
82  unsigned char MaxAtomicPromoteWidth, MaxAtomicInlineWidth;
83  unsigned short MaxVectorAlign;
84  const char *DescriptionString;
85  const char *UserLabelPrefix;
86  const char *MCountName;
87  const llvm::fltSemantics *HalfFormat, *FloatFormat, *DoubleFormat,
88    *LongDoubleFormat;
89  unsigned char RegParmMax, SSERegParmMax;
90  TargetCXXABI CXXABI;
91  const LangAS::Map *AddrSpaceMap;
92
93  mutable StringRef PlatformName;
94  mutable VersionTuple PlatformMinVersion;
95
96  unsigned HasAlignMac68kSupport : 1;
97  unsigned RealTypeUsesObjCFPRet : 3;
98  unsigned ComplexLongDoubleUsesFP2Ret : 1;
99
100  // TargetInfo Constructor.  Default initializes all fields.
101  TargetInfo(const std::string &T);
102
103public:
104  /// \brief Construct a target for the given options.
105  ///
106  /// \param Opts - The options to use to initialize the target. The target may
107  /// modify the options to canonicalize the target feature information to match
108  /// what the backend expects.
109  static TargetInfo* CreateTargetInfo(DiagnosticsEngine &Diags,
110                                      TargetOptions &Opts);
111
112  virtual ~TargetInfo();
113
114  ///===---- Target Data Type Query Methods -------------------------------===//
115  enum IntType {
116    NoInt = 0,
117    SignedShort,
118    UnsignedShort,
119    SignedInt,
120    UnsignedInt,
121    SignedLong,
122    UnsignedLong,
123    SignedLongLong,
124    UnsignedLongLong
125  };
126
127  enum RealType {
128    Float = 0,
129    Double,
130    LongDouble
131  };
132
133  /// \brief The different kinds of __builtin_va_list types defined by
134  /// the target implementation.
135  enum BuiltinVaListKind {
136    /// typedef char* __builtin_va_list;
137    CharPtrBuiltinVaList = 0,
138
139    /// typedef void* __builtin_va_list;
140    VoidPtrBuiltinVaList,
141
142    /// __builtin_va_list as defined by the PNaCl ABI:
143    /// http://www.chromium.org/nativeclient/pnacl/bitcode-abi#TOC-Machine-Types
144    PNaClABIBuiltinVaList,
145
146    /// __builtin_va_list as defined by the Power ABI:
147    /// https://www.power.org
148    ///        /resources/downloads/Power-Arch-32-bit-ABI-supp-1.0-Embedded.pdf
149    PowerABIBuiltinVaList,
150
151    /// __builtin_va_list as defined by the x86-64 ABI:
152    /// http://www.x86-64.org/documentation/abi.pdf
153    X86_64ABIBuiltinVaList
154  };
155
156protected:
157  IntType SizeType, IntMaxType, UIntMaxType, PtrDiffType, IntPtrType, WCharType,
158          WIntType, Char16Type, Char32Type, Int64Type, SigAtomicType;
159
160  /// \brief Whether Objective-C's built-in boolean type should be signed char.
161  ///
162  /// Otherwise, when this flag is not set, the normal built-in boolean type is
163  /// used.
164  unsigned UseSignedCharForObjCBool : 1;
165
166  /// Control whether the alignment of bit-field types is respected when laying
167  /// out structures. If true, then the alignment of the bit-field type will be
168  /// used to (a) impact the alignment of the containing structure, and (b)
169  /// ensure that the individual bit-field will not straddle an alignment
170  /// boundary.
171  unsigned UseBitFieldTypeAlignment : 1;
172
173  /// \brief Whether zero length bitfields (e.g., int : 0;) force alignment of
174  /// the next bitfield.
175  ///
176  /// If the alignment of the zero length bitfield is greater than the member
177  /// that follows it, `bar', `bar' will be aligned as the type of the
178  /// zero-length bitfield.
179  unsigned UseZeroLengthBitfieldAlignment : 1;
180
181  /// If non-zero, specifies a fixed alignment value for bitfields that follow
182  /// zero length bitfield, regardless of the zero length bitfield type.
183  unsigned ZeroLengthBitfieldBoundary;
184
185public:
186  IntType getSizeType() const { return SizeType; }
187  IntType getIntMaxType() const { return IntMaxType; }
188  IntType getUIntMaxType() const { return UIntMaxType; }
189  IntType getPtrDiffType(unsigned AddrSpace) const {
190    return AddrSpace == 0 ? PtrDiffType : getPtrDiffTypeV(AddrSpace);
191  }
192  IntType getIntPtrType() const { return IntPtrType; }
193  IntType getWCharType() const { return WCharType; }
194  IntType getWIntType() const { return WIntType; }
195  IntType getChar16Type() const { return Char16Type; }
196  IntType getChar32Type() const { return Char32Type; }
197  IntType getInt64Type() const { return Int64Type; }
198  IntType getSigAtomicType() const { return SigAtomicType; }
199
200
201  /// \brief Return the width (in bits) of the specified integer type enum.
202  ///
203  /// For example, SignedInt -> getIntWidth().
204  unsigned getTypeWidth(IntType T) const;
205
206  /// \brief Return the alignment (in bits) of the specified integer type enum.
207  ///
208  /// For example, SignedInt -> getIntAlign().
209  unsigned getTypeAlign(IntType T) const;
210
211  /// \brief Returns true if the type is signed; false otherwise.
212  static bool isTypeSigned(IntType T);
213
214  /// \brief Return the width of pointers on this target, for the
215  /// specified address space.
216  uint64_t getPointerWidth(unsigned AddrSpace) const {
217    return AddrSpace == 0 ? PointerWidth : getPointerWidthV(AddrSpace);
218  }
219  uint64_t getPointerAlign(unsigned AddrSpace) const {
220    return AddrSpace == 0 ? PointerAlign : getPointerAlignV(AddrSpace);
221  }
222
223  /// \brief Return the size of '_Bool' and C++ 'bool' for this target, in bits.
224  unsigned getBoolWidth() const { return BoolWidth; }
225
226  /// \brief Return the alignment of '_Bool' and C++ 'bool' for this target.
227  unsigned getBoolAlign() const { return BoolAlign; }
228
229  unsigned getCharWidth() const { return 8; } // FIXME
230  unsigned getCharAlign() const { return 8; } // FIXME
231
232  /// \brief Return the size of 'signed short' and 'unsigned short' for this
233  /// target, in bits.
234  unsigned getShortWidth() const { return 16; } // FIXME
235
236  /// \brief Return the alignment of 'signed short' and 'unsigned short' for
237  /// this target.
238  unsigned getShortAlign() const { return 16; } // FIXME
239
240  /// getIntWidth/Align - Return the size of 'signed int' and 'unsigned int' for
241  /// this target, in bits.
242  unsigned getIntWidth() const { return IntWidth; }
243  unsigned getIntAlign() const { return IntAlign; }
244
245  /// getLongWidth/Align - Return the size of 'signed long' and 'unsigned long'
246  /// for this target, in bits.
247  unsigned getLongWidth() const { return LongWidth; }
248  unsigned getLongAlign() const { return LongAlign; }
249
250  /// getLongLongWidth/Align - Return the size of 'signed long long' and
251  /// 'unsigned long long' for this target, in bits.
252  unsigned getLongLongWidth() const { return LongLongWidth; }
253  unsigned getLongLongAlign() const { return LongLongAlign; }
254
255  /// \brief Return the alignment that is suitable for storing any
256  /// object with a fundamental alignment requirement.
257  unsigned getSuitableAlign() const { return SuitableAlign; }
258
259  /// getWCharWidth/Align - Return the size of 'wchar_t' for this target, in
260  /// bits.
261  unsigned getWCharWidth() const { return getTypeWidth(WCharType); }
262  unsigned getWCharAlign() const { return getTypeAlign(WCharType); }
263
264  /// getChar16Width/Align - Return the size of 'char16_t' for this target, in
265  /// bits.
266  unsigned getChar16Width() const { return getTypeWidth(Char16Type); }
267  unsigned getChar16Align() const { return getTypeAlign(Char16Type); }
268
269  /// getChar32Width/Align - Return the size of 'char32_t' for this target, in
270  /// bits.
271  unsigned getChar32Width() const { return getTypeWidth(Char32Type); }
272  unsigned getChar32Align() const { return getTypeAlign(Char32Type); }
273
274  /// getHalfWidth/Align/Format - Return the size/align/format of 'half'.
275  unsigned getHalfWidth() const { return HalfWidth; }
276  unsigned getHalfAlign() const { return HalfAlign; }
277  const llvm::fltSemantics &getHalfFormat() const { return *HalfFormat; }
278
279  /// getFloatWidth/Align/Format - Return the size/align/format of 'float'.
280  unsigned getFloatWidth() const { return FloatWidth; }
281  unsigned getFloatAlign() const { return FloatAlign; }
282  const llvm::fltSemantics &getFloatFormat() const { return *FloatFormat; }
283
284  /// getDoubleWidth/Align/Format - Return the size/align/format of 'double'.
285  unsigned getDoubleWidth() const { return DoubleWidth; }
286  unsigned getDoubleAlign() const { return DoubleAlign; }
287  const llvm::fltSemantics &getDoubleFormat() const { return *DoubleFormat; }
288
289  /// getLongDoubleWidth/Align/Format - Return the size/align/format of 'long
290  /// double'.
291  unsigned getLongDoubleWidth() const { return LongDoubleWidth; }
292  unsigned getLongDoubleAlign() const { return LongDoubleAlign; }
293  const llvm::fltSemantics &getLongDoubleFormat() const {
294    return *LongDoubleFormat;
295  }
296
297  /// \brief Return the value for the C99 FLT_EVAL_METHOD macro.
298  virtual unsigned getFloatEvalMethod() const { return 0; }
299
300  // getLargeArrayMinWidth/Align - Return the minimum array size that is
301  // 'large' and its alignment.
302  unsigned getLargeArrayMinWidth() const { return LargeArrayMinWidth; }
303  unsigned getLargeArrayAlign() const { return LargeArrayAlign; }
304
305  /// \brief Return the maximum width lock-free atomic operation which will
306  /// ever be supported for the given target
307  unsigned getMaxAtomicPromoteWidth() const { return MaxAtomicPromoteWidth; }
308  /// \brief Return the maximum width lock-free atomic operation which can be
309  /// inlined given the supported features of the given target.
310  unsigned getMaxAtomicInlineWidth() const { return MaxAtomicInlineWidth; }
311
312  /// \brief Return the maximum vector alignment supported for the given target.
313  unsigned getMaxVectorAlign() const { return MaxVectorAlign; }
314
315  /// \brief Return the size of intmax_t and uintmax_t for this target, in bits.
316  unsigned getIntMaxTWidth() const {
317    return getTypeWidth(IntMaxType);
318  }
319
320  /// \brief Return the "preferred" register width on this target.
321  uint64_t getRegisterWidth() const {
322    // Currently we assume the register width on the target matches the pointer
323    // width, we can introduce a new variable for this if/when some target wants
324    // it.
325    return LongWidth;
326  }
327
328  /// \brief Returns the default value of the __USER_LABEL_PREFIX__ macro,
329  /// which is the prefix given to user symbols by default.
330  ///
331  /// On most platforms this is "_", but it is "" on some, and "." on others.
332  const char *getUserLabelPrefix() const {
333    return UserLabelPrefix;
334  }
335
336  /// \brief Returns the name of the mcount instrumentation function.
337  const char *getMCountName() const {
338    return MCountName;
339  }
340
341  /// \brief Check if the Objective-C built-in boolean type should be signed
342  /// char.
343  ///
344  /// Otherwise, if this returns false, the normal built-in boolean type
345  /// should also be used for Objective-C.
346  bool useSignedCharForObjCBool() const {
347    return UseSignedCharForObjCBool;
348  }
349  void noSignedCharForObjCBool() {
350    UseSignedCharForObjCBool = false;
351  }
352
353  /// \brief Check whether the alignment of bit-field types is respected
354  /// when laying out structures.
355  bool useBitFieldTypeAlignment() const {
356    return UseBitFieldTypeAlignment;
357  }
358
359  /// \brief Check whether zero length bitfields should force alignment of
360  /// the next member.
361  bool useZeroLengthBitfieldAlignment() const {
362    return UseZeroLengthBitfieldAlignment;
363  }
364
365  /// \brief Get the fixed alignment value in bits for a member that follows
366  /// a zero length bitfield.
367  unsigned getZeroLengthBitfieldBoundary() const {
368    return ZeroLengthBitfieldBoundary;
369  }
370
371  /// \brief Check whether this target support '\#pragma options align=mac68k'.
372  bool hasAlignMac68kSupport() const {
373    return HasAlignMac68kSupport;
374  }
375
376  /// \brief Return the user string for the specified integer type enum.
377  ///
378  /// For example, SignedShort -> "short".
379  static const char *getTypeName(IntType T);
380
381  /// \brief Return the constant suffix for the specified integer type enum.
382  ///
383  /// For example, SignedLong -> "L".
384  static const char *getTypeConstantSuffix(IntType T);
385
386  /// \brief Check whether the given real type should use the "fpret" flavor of
387  /// Objective-C message passing on this target.
388  bool useObjCFPRetForRealType(RealType T) const {
389    return RealTypeUsesObjCFPRet & (1 << T);
390  }
391
392  /// \brief Check whether _Complex long double should use the "fp2ret" flavor
393  /// of Objective-C message passing on this target.
394  bool useObjCFP2RetForComplexLongDouble() const {
395    return ComplexLongDoubleUsesFP2Ret;
396  }
397
398  ///===---- Other target property query methods --------------------------===//
399
400  /// \brief Appends the target-specific \#define values for this
401  /// target set to the specified buffer.
402  virtual void getTargetDefines(const LangOptions &Opts,
403                                MacroBuilder &Builder) const = 0;
404
405
406  /// Return information about target-specific builtins for
407  /// the current primary target, and info about which builtins are non-portable
408  /// across the current set of primary and secondary targets.
409  virtual void getTargetBuiltins(const Builtin::Info *&Records,
410                                 unsigned &NumRecords) const = 0;
411
412  /// The __builtin_clz* and __builtin_ctz* built-in
413  /// functions are specified to have undefined results for zero inputs, but
414  /// on targets that support these operations in a way that provides
415  /// well-defined results for zero without loss of performance, it is a good
416  /// idea to avoid optimizing based on that undef behavior.
417  virtual bool isCLZForZeroUndef() const { return true; }
418
419  /// \brief Returns the kind of __builtin_va_list type that should be used
420  /// with this target.
421  virtual BuiltinVaListKind getBuiltinVaListKind() const = 0;
422
423  /// \brief Returns whether the passed in string is a valid clobber in an
424  /// inline asm statement.
425  ///
426  /// This is used by Sema.
427  bool isValidClobber(StringRef Name) const;
428
429  /// \brief Returns whether the passed in string is a valid register name
430  /// according to GCC.
431  ///
432  /// This is used by Sema for inline asm statements.
433  bool isValidGCCRegisterName(StringRef Name) const;
434
435  /// \brief Returns the "normalized" GCC register name.
436  ///
437  /// For example, on x86 it will return "ax" when "eax" is passed in.
438  StringRef getNormalizedGCCRegisterName(StringRef Name) const;
439
440  struct ConstraintInfo {
441    enum {
442      CI_None = 0x00,
443      CI_AllowsMemory = 0x01,
444      CI_AllowsRegister = 0x02,
445      CI_ReadWrite = 0x04,       // "+r" output constraint (read and write).
446      CI_HasMatchingInput = 0x08 // This output operand has a matching input.
447    };
448    unsigned Flags;
449    int TiedOperand;
450
451    std::string ConstraintStr;  // constraint: "=rm"
452    std::string Name;           // Operand name: [foo] with no []'s.
453  public:
454    ConstraintInfo(StringRef ConstraintStr, StringRef Name)
455      : Flags(0), TiedOperand(-1), ConstraintStr(ConstraintStr.str()),
456      Name(Name.str()) {}
457
458    const std::string &getConstraintStr() const { return ConstraintStr; }
459    const std::string &getName() const { return Name; }
460    bool isReadWrite() const { return (Flags & CI_ReadWrite) != 0; }
461    bool allowsRegister() const { return (Flags & CI_AllowsRegister) != 0; }
462    bool allowsMemory() const { return (Flags & CI_AllowsMemory) != 0; }
463
464    /// \brief Return true if this output operand has a matching
465    /// (tied) input operand.
466    bool hasMatchingInput() const { return (Flags & CI_HasMatchingInput) != 0; }
467
468    /// \brief Return true if this input operand is a matching
469    /// constraint that ties it to an output operand.
470    ///
471    /// If this returns true then getTiedOperand will indicate which output
472    /// operand this is tied to.
473    bool hasTiedOperand() const { return TiedOperand != -1; }
474    unsigned getTiedOperand() const {
475      assert(hasTiedOperand() && "Has no tied operand!");
476      return (unsigned)TiedOperand;
477    }
478
479    void setIsReadWrite() { Flags |= CI_ReadWrite; }
480    void setAllowsMemory() { Flags |= CI_AllowsMemory; }
481    void setAllowsRegister() { Flags |= CI_AllowsRegister; }
482    void setHasMatchingInput() { Flags |= CI_HasMatchingInput; }
483
484    /// \brief Indicate that this is an input operand that is tied to
485    /// the specified output operand.
486    ///
487    /// Copy over the various constraint information from the output.
488    void setTiedOperand(unsigned N, ConstraintInfo &Output) {
489      Output.setHasMatchingInput();
490      Flags = Output.Flags;
491      TiedOperand = N;
492      // Don't copy Name or constraint string.
493    }
494  };
495
496  // validateOutputConstraint, validateInputConstraint - Checks that
497  // a constraint is valid and provides information about it.
498  // FIXME: These should return a real error instead of just true/false.
499  bool validateOutputConstraint(ConstraintInfo &Info) const;
500  bool validateInputConstraint(ConstraintInfo *OutputConstraints,
501                               unsigned NumOutputs,
502                               ConstraintInfo &info) const;
503  bool resolveSymbolicName(const char *&Name,
504                           ConstraintInfo *OutputConstraints,
505                           unsigned NumOutputs, unsigned &Index) const;
506
507  // Constraint parm will be left pointing at the last character of
508  // the constraint.  In practice, it won't be changed unless the
509  // constraint is longer than one character.
510  virtual std::string convertConstraint(const char *&Constraint) const {
511    // 'p' defaults to 'r', but can be overridden by targets.
512    if (*Constraint == 'p')
513      return std::string("r");
514    return std::string(1, *Constraint);
515  }
516
517  /// \brief Returns a string of target-specific clobbers, in LLVM format.
518  virtual const char *getClobbers() const = 0;
519
520
521  /// \brief Returns the target triple of the primary target.
522  const llvm::Triple &getTriple() const {
523    return Triple;
524  }
525
526  const char *getTargetDescription() const {
527    return DescriptionString;
528  }
529
530  struct GCCRegAlias {
531    const char * const Aliases[5];
532    const char * const Register;
533  };
534
535  struct AddlRegName {
536    const char * const Names[5];
537    const unsigned RegNum;
538  };
539
540  /// \brief Does this target support "protected" visibility?
541  ///
542  /// Any target which dynamic libraries will naturally support
543  /// something like "default" (meaning that the symbol is visible
544  /// outside this shared object) and "hidden" (meaning that it isn't)
545  /// visibilities, but "protected" is really an ELF-specific concept
546  /// with weird semantics designed around the convenience of dynamic
547  /// linker implementations.  Which is not to suggest that there's
548  /// consistent target-independent semantics for "default" visibility
549  /// either; the entire thing is pretty badly mangled.
550  virtual bool hasProtectedVisibility() const { return true; }
551
552  virtual bool useGlobalsForAutomaticVariables() const { return false; }
553
554  /// \brief Return the section to use for CFString literals, or 0 if no
555  /// special section is used.
556  virtual const char *getCFStringSection() const {
557    return "__DATA,__cfstring";
558  }
559
560  /// \brief Return the section to use for NSString literals, or 0 if no
561  /// special section is used.
562  virtual const char *getNSStringSection() const {
563    return "__OBJC,__cstring_object,regular,no_dead_strip";
564  }
565
566  /// \brief Return the section to use for NSString literals, or 0 if no
567  /// special section is used (NonFragile ABI).
568  virtual const char *getNSStringNonFragileABISection() const {
569    return "__DATA, __objc_stringobj, regular, no_dead_strip";
570  }
571
572  /// \brief An optional hook that targets can implement to perform semantic
573  /// checking on attribute((section("foo"))) specifiers.
574  ///
575  /// In this case, "foo" is passed in to be checked.  If the section
576  /// specifier is invalid, the backend should return a non-empty string
577  /// that indicates the problem.
578  ///
579  /// This hook is a simple quality of implementation feature to catch errors
580  /// and give good diagnostics in cases when the assembler or code generator
581  /// would otherwise reject the section specifier.
582  ///
583  virtual std::string isValidSectionSpecifier(StringRef SR) const {
584    return "";
585  }
586
587  /// \brief Set forced language options.
588  ///
589  /// Apply changes to the target information with respect to certain
590  /// language options which change the target configuration.
591  virtual void setForcedLangOptions(LangOptions &Opts);
592
593  /// \brief Get the default set of target features for the CPU;
594  /// this should include all legal feature strings on the target.
595  virtual void getDefaultFeatures(llvm::StringMap<bool> &Features) const {
596  }
597
598  /// \brief Get the ABI currently in use.
599  virtual const char *getABI() const {
600    return "";
601  }
602
603  /// \brief Get the C++ ABI currently in use.
604  virtual TargetCXXABI getCXXABI() const {
605    return CXXABI;
606  }
607
608  /// \brief Target the specified CPU.
609  ///
610  /// \return  False on error (invalid CPU name).
611  virtual bool setCPU(const std::string &Name) {
612    return false;
613  }
614
615  /// \brief Use the specified ABI.
616  ///
617  /// \return False on error (invalid ABI name).
618  virtual bool setABI(const std::string &Name) {
619    return false;
620  }
621
622  /// \brief Use this specified C++ ABI.
623  ///
624  /// \return False on error (invalid C++ ABI name).
625  bool setCXXABI(const std::string &Name) {
626    static const TargetCXXABI Unknown = static_cast<TargetCXXABI>(-1);
627    TargetCXXABI ABI = llvm::StringSwitch<TargetCXXABI>(Name)
628      .Case("arm", CXXABI_ARM)
629      .Case("itanium", CXXABI_Itanium)
630      .Case("microsoft", CXXABI_Microsoft)
631      .Default(Unknown);
632    if (ABI == Unknown) return false;
633    return setCXXABI(ABI);
634  }
635
636  /// \brief Set the C++ ABI to be used by this implementation.
637  ///
638  /// \return False on error (ABI not valid on this target)
639  virtual bool setCXXABI(TargetCXXABI ABI) {
640    CXXABI = ABI;
641    return true;
642  }
643
644  /// \brief Enable or disable a specific target feature;
645  /// the feature name must be valid.
646  ///
647  /// \return False on error (invalid feature name).
648  virtual bool setFeatureEnabled(llvm::StringMap<bool> &Features,
649                                 StringRef Name,
650                                 bool Enabled) const {
651    return false;
652  }
653
654  /// \brief Perform initialization based on the user configured
655  /// set of features (e.g., +sse4).
656  ///
657  /// The list is guaranteed to have at most one entry per feature.
658  ///
659  /// The target may modify the features list, to change which options are
660  /// passed onwards to the backend.
661  virtual void HandleTargetFeatures(std::vector<std::string> &Features) {
662  }
663
664  /// \brief Determine whether the given target has the given feature.
665  virtual bool hasFeature(StringRef Feature) const {
666    return false;
667  }
668
669  // \brief Returns maximal number of args passed in registers.
670  unsigned getRegParmMax() const {
671    assert(RegParmMax < 7 && "RegParmMax value is larger than AST can handle");
672    return RegParmMax;
673  }
674
675  /// \brief Whether the target supports thread-local storage.
676  bool isTLSSupported() const {
677    return TLSSupported;
678  }
679
680  /// \brief Return true if {|} are normal characters in the asm string.
681  ///
682  /// If this returns false (the default), then {abc|xyz} is syntax
683  /// that says that when compiling for asm variant #0, "abc" should be
684  /// generated, but when compiling for asm variant #1, "xyz" should be
685  /// generated.
686  bool hasNoAsmVariants() const {
687    return NoAsmVariants;
688  }
689
690  /// \brief Return the register number that __builtin_eh_return_regno would
691  /// return with the specified argument.
692  virtual int getEHDataRegisterNumber(unsigned RegNo) const {
693    return -1;
694  }
695
696  /// \brief Return the section to use for C++ static initialization functions.
697  virtual const char *getStaticInitSectionSpecifier() const {
698    return 0;
699  }
700
701  const LangAS::Map &getAddressSpaceMap() const {
702    return *AddrSpaceMap;
703  }
704
705  /// \brief Retrieve the name of the platform as it is used in the
706  /// availability attribute.
707  StringRef getPlatformName() const { return PlatformName; }
708
709  /// \brief Retrieve the minimum desired version of the platform, to
710  /// which the program should be compiled.
711  VersionTuple getPlatformMinVersion() const { return PlatformMinVersion; }
712
713  bool isBigEndian() const { return BigEndian; }
714
715protected:
716  virtual uint64_t getPointerWidthV(unsigned AddrSpace) const {
717    return PointerWidth;
718  }
719  virtual uint64_t getPointerAlignV(unsigned AddrSpace) const {
720    return PointerAlign;
721  }
722  virtual enum IntType getPtrDiffTypeV(unsigned AddrSpace) const {
723    return PtrDiffType;
724  }
725  virtual void getGCCRegNames(const char * const *&Names,
726                              unsigned &NumNames) const = 0;
727  virtual void getGCCRegAliases(const GCCRegAlias *&Aliases,
728                                unsigned &NumAliases) const = 0;
729  virtual void getGCCAddlRegNames(const AddlRegName *&Addl,
730				  unsigned &NumAddl) const {
731    Addl = 0;
732    NumAddl = 0;
733  }
734  virtual bool validateAsmConstraint(const char *&Name,
735                                     TargetInfo::ConstraintInfo &info) const= 0;
736};
737
738}  // end namespace clang
739
740#endif
741