CodeGenFunction.h revision 1b726771d00762fb5c4c2638e60d134c385493ae
1//===-- CodeGenFunction.h - Per-Function state for LLVM CodeGen -*- 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// This is the internal per-function state used for llvm translation.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef CLANG_CODEGEN_CODEGENFUNCTION_H
15#define CLANG_CODEGEN_CODEGENFUNCTION_H
16
17#include "clang/AST/Type.h"
18#include "clang/AST/ExprCXX.h"
19#include "clang/AST/ExprObjC.h"
20#include "clang/AST/CharUnits.h"
21#include "clang/Basic/TargetInfo.h"
22#include "llvm/ADT/DenseMap.h"
23#include "llvm/ADT/SmallVector.h"
24#include "llvm/Support/ValueHandle.h"
25#include "CodeGenModule.h"
26#include "CGBlocks.h"
27#include "CGBuilder.h"
28#include "CGCall.h"
29#include "CGCXX.h"
30#include "CGValue.h"
31
32namespace llvm {
33  class BasicBlock;
34  class LLVMContext;
35  class MDNode;
36  class Module;
37  class SwitchInst;
38  class Twine;
39  class Value;
40  class CallSite;
41}
42
43namespace clang {
44  class APValue;
45  class ASTContext;
46  class CXXDestructorDecl;
47  class CXXTryStmt;
48  class Decl;
49  class EnumConstantDecl;
50  class FunctionDecl;
51  class FunctionProtoType;
52  class LabelStmt;
53  class ObjCContainerDecl;
54  class ObjCInterfaceDecl;
55  class ObjCIvarDecl;
56  class ObjCMethodDecl;
57  class ObjCImplementationDecl;
58  class ObjCPropertyImplDecl;
59  class TargetInfo;
60  class TargetCodeGenInfo;
61  class VarDecl;
62  class ObjCForCollectionStmt;
63  class ObjCAtTryStmt;
64  class ObjCAtThrowStmt;
65  class ObjCAtSynchronizedStmt;
66
67namespace CodeGen {
68  class CodeGenTypes;
69  class CGDebugInfo;
70  class CGFunctionInfo;
71  class CGRecordLayout;
72  class CGBlockInfo;
73  class CGCXXABI;
74
75/// A branch fixup.  These are required when emitting a goto to a
76/// label which hasn't been emitted yet.  The goto is optimistically
77/// emitted as a branch to the basic block for the label, and (if it
78/// occurs in a scope with non-trivial cleanups) a fixup is added to
79/// the innermost cleanup.  When a (normal) cleanup is popped, any
80/// unresolved fixups in that scope are threaded through the cleanup.
81struct BranchFixup {
82  /// The block containing the terminator which needs to be modified
83  /// into a switch if this fixup is resolved into the current scope.
84  /// If null, LatestBranch points directly to the destination.
85  llvm::BasicBlock *OptimisticBranchBlock;
86
87  /// The ultimate destination of the branch.
88  ///
89  /// This can be set to null to indicate that this fixup was
90  /// successfully resolved.
91  llvm::BasicBlock *Destination;
92
93  /// The destination index value.
94  unsigned DestinationIndex;
95
96  /// The initial branch of the fixup.
97  llvm::BranchInst *InitialBranch;
98};
99
100enum CleanupKind {
101  EHCleanup = 0x1,
102  NormalCleanup = 0x2,
103  NormalAndEHCleanup = EHCleanup | NormalCleanup,
104
105  InactiveCleanup = 0x4,
106  InactiveEHCleanup = EHCleanup | InactiveCleanup,
107  InactiveNormalCleanup = NormalCleanup | InactiveCleanup,
108  InactiveNormalAndEHCleanup = NormalAndEHCleanup | InactiveCleanup
109};
110
111/// A stack of scopes which respond to exceptions, including cleanups
112/// and catch blocks.
113class EHScopeStack {
114public:
115  /// A saved depth on the scope stack.  This is necessary because
116  /// pushing scopes onto the stack invalidates iterators.
117  class stable_iterator {
118    friend class EHScopeStack;
119
120    /// Offset from StartOfData to EndOfBuffer.
121    ptrdiff_t Size;
122
123    stable_iterator(ptrdiff_t Size) : Size(Size) {}
124
125  public:
126    static stable_iterator invalid() { return stable_iterator(-1); }
127    stable_iterator() : Size(-1) {}
128
129    bool isValid() const { return Size >= 0; }
130
131    /// Returns true if this scope encloses I.
132    /// Returns false if I is invalid.
133    /// This scope must be valid.
134    bool encloses(stable_iterator I) const { return Size <= I.Size; }
135
136    /// Returns true if this scope strictly encloses I: that is,
137    /// if it encloses I and is not I.
138    /// Returns false is I is invalid.
139    /// This scope must be valid.
140    bool strictlyEncloses(stable_iterator I) const { return Size < I.Size; }
141
142    friend bool operator==(stable_iterator A, stable_iterator B) {
143      return A.Size == B.Size;
144    }
145    friend bool operator!=(stable_iterator A, stable_iterator B) {
146      return A.Size != B.Size;
147    }
148  };
149
150  /// Information for lazily generating a cleanup.  Subclasses must be
151  /// POD-like: cleanups will not be destructed, and they will be
152  /// allocated on the cleanup stack and freely copied and moved
153  /// around.
154  ///
155  /// Cleanup implementations should generally be declared in an
156  /// anonymous namespace.
157  class Cleanup {
158  public:
159    // Anchor the construction vtable.  We use the destructor because
160    // gcc gives an obnoxious warning if there are virtual methods
161    // with an accessible non-virtual destructor.  Unfortunately,
162    // declaring this destructor makes it non-trivial, but there
163    // doesn't seem to be any other way around this warning.
164    //
165    // This destructor will never be called.
166    virtual ~Cleanup();
167
168    /// Emit the cleanup.  For normal cleanups, this is run in the
169    /// same EH context as when the cleanup was pushed, i.e. the
170    /// immediately-enclosing context of the cleanup scope.  For
171    /// EH cleanups, this is run in a terminate context.
172    ///
173    // \param IsForEHCleanup true if this is for an EH cleanup, false
174    ///  if for a normal cleanup.
175    virtual void Emit(CodeGenFunction &CGF, bool IsForEHCleanup) = 0;
176  };
177
178private:
179  // The implementation for this class is in CGException.h and
180  // CGException.cpp; the definition is here because it's used as a
181  // member of CodeGenFunction.
182
183  /// The start of the scope-stack buffer, i.e. the allocated pointer
184  /// for the buffer.  All of these pointers are either simultaneously
185  /// null or simultaneously valid.
186  char *StartOfBuffer;
187
188  /// The end of the buffer.
189  char *EndOfBuffer;
190
191  /// The first valid entry in the buffer.
192  char *StartOfData;
193
194  /// The innermost normal cleanup on the stack.
195  stable_iterator InnermostNormalCleanup;
196
197  /// The innermost EH cleanup on the stack.
198  stable_iterator InnermostEHCleanup;
199
200  /// The number of catches on the stack.
201  unsigned CatchDepth;
202
203  /// The current EH destination index.  Reset to FirstCatchIndex
204  /// whenever the last EH cleanup is popped.
205  unsigned NextEHDestIndex;
206  enum { FirstEHDestIndex = 1 };
207
208  /// The current set of branch fixups.  A branch fixup is a jump to
209  /// an as-yet unemitted label, i.e. a label for which we don't yet
210  /// know the EH stack depth.  Whenever we pop a cleanup, we have
211  /// to thread all the current branch fixups through it.
212  ///
213  /// Fixups are recorded as the Use of the respective branch or
214  /// switch statement.  The use points to the final destination.
215  /// When popping out of a cleanup, these uses are threaded through
216  /// the cleanup and adjusted to point to the new cleanup.
217  ///
218  /// Note that branches are allowed to jump into protected scopes
219  /// in certain situations;  e.g. the following code is legal:
220  ///     struct A { ~A(); }; // trivial ctor, non-trivial dtor
221  ///     goto foo;
222  ///     A a;
223  ///    foo:
224  ///     bar();
225  llvm::SmallVector<BranchFixup, 8> BranchFixups;
226
227  char *allocate(size_t Size);
228
229  void *pushCleanup(CleanupKind K, size_t DataSize);
230
231public:
232  EHScopeStack() : StartOfBuffer(0), EndOfBuffer(0), StartOfData(0),
233                   InnermostNormalCleanup(stable_end()),
234                   InnermostEHCleanup(stable_end()),
235                   CatchDepth(0), NextEHDestIndex(FirstEHDestIndex) {}
236  ~EHScopeStack() { delete[] StartOfBuffer; }
237
238  // Variadic templates would make this not terrible.
239
240  /// Push a lazily-created cleanup on the stack.
241  template <class T>
242  void pushCleanup(CleanupKind Kind) {
243    void *Buffer = pushCleanup(Kind, sizeof(T));
244    Cleanup *Obj = new(Buffer) T();
245    (void) Obj;
246  }
247
248  /// Push a lazily-created cleanup on the stack.
249  template <class T, class A0>
250  void pushCleanup(CleanupKind Kind, A0 a0) {
251    void *Buffer = pushCleanup(Kind, sizeof(T));
252    Cleanup *Obj = new(Buffer) T(a0);
253    (void) Obj;
254  }
255
256  /// Push a lazily-created cleanup on the stack.
257  template <class T, class A0, class A1>
258  void pushCleanup(CleanupKind Kind, A0 a0, A1 a1) {
259    void *Buffer = pushCleanup(Kind, sizeof(T));
260    Cleanup *Obj = new(Buffer) T(a0, a1);
261    (void) Obj;
262  }
263
264  /// Push a lazily-created cleanup on the stack.
265  template <class T, class A0, class A1, class A2>
266  void pushCleanup(CleanupKind Kind, A0 a0, A1 a1, A2 a2) {
267    void *Buffer = pushCleanup(Kind, sizeof(T));
268    Cleanup *Obj = new(Buffer) T(a0, a1, a2);
269    (void) Obj;
270  }
271
272  /// Push a lazily-created cleanup on the stack.
273  template <class T, class A0, class A1, class A2, class A3>
274  void pushCleanup(CleanupKind Kind, A0 a0, A1 a1, A2 a2, A3 a3) {
275    void *Buffer = pushCleanup(Kind, sizeof(T));
276    Cleanup *Obj = new(Buffer) T(a0, a1, a2, a3);
277    (void) Obj;
278  }
279
280  /// Push a lazily-created cleanup on the stack.
281  template <class T, class A0, class A1, class A2, class A3, class A4>
282  void pushCleanup(CleanupKind Kind, A0 a0, A1 a1, A2 a2, A3 a3, A4 a4) {
283    void *Buffer = pushCleanup(Kind, sizeof(T));
284    Cleanup *Obj = new(Buffer) T(a0, a1, a2, a3, a4);
285    (void) Obj;
286  }
287
288  // Feel free to add more variants of the following:
289
290  /// Push a cleanup with non-constant storage requirements on the
291  /// stack.  The cleanup type must provide an additional static method:
292  ///   static size_t getExtraSize(size_t);
293  /// The argument to this method will be the value N, which will also
294  /// be passed as the first argument to the constructor.
295  ///
296  /// The data stored in the extra storage must obey the same
297  /// restrictions as normal cleanup member data.
298  ///
299  /// The pointer returned from this method is valid until the cleanup
300  /// stack is modified.
301  template <class T, class A0, class A1, class A2>
302  T *pushCleanupWithExtra(CleanupKind Kind, size_t N, A0 a0, A1 a1, A2 a2) {
303    void *Buffer = pushCleanup(Kind, sizeof(T) + T::getExtraSize(N));
304    return new (Buffer) T(N, a0, a1, a2);
305  }
306
307  /// Pops a cleanup scope off the stack.  This should only be called
308  /// by CodeGenFunction::PopCleanupBlock.
309  void popCleanup();
310
311  /// Push a set of catch handlers on the stack.  The catch is
312  /// uninitialized and will need to have the given number of handlers
313  /// set on it.
314  class EHCatchScope *pushCatch(unsigned NumHandlers);
315
316  /// Pops a catch scope off the stack.
317  void popCatch();
318
319  /// Push an exceptions filter on the stack.
320  class EHFilterScope *pushFilter(unsigned NumFilters);
321
322  /// Pops an exceptions filter off the stack.
323  void popFilter();
324
325  /// Push a terminate handler on the stack.
326  void pushTerminate();
327
328  /// Pops a terminate handler off the stack.
329  void popTerminate();
330
331  /// Determines whether the exception-scopes stack is empty.
332  bool empty() const { return StartOfData == EndOfBuffer; }
333
334  bool requiresLandingPad() const {
335    return (CatchDepth || hasEHCleanups());
336  }
337
338  /// Determines whether there are any normal cleanups on the stack.
339  bool hasNormalCleanups() const {
340    return InnermostNormalCleanup != stable_end();
341  }
342
343  /// Returns the innermost normal cleanup on the stack, or
344  /// stable_end() if there are no normal cleanups.
345  stable_iterator getInnermostNormalCleanup() const {
346    return InnermostNormalCleanup;
347  }
348  stable_iterator getInnermostActiveNormalCleanup() const; // CGException.h
349
350  /// Determines whether there are any EH cleanups on the stack.
351  bool hasEHCleanups() const {
352    return InnermostEHCleanup != stable_end();
353  }
354
355  /// Returns the innermost EH cleanup on the stack, or stable_end()
356  /// if there are no EH cleanups.
357  stable_iterator getInnermostEHCleanup() const {
358    return InnermostEHCleanup;
359  }
360  stable_iterator getInnermostActiveEHCleanup() const; // CGException.h
361
362  /// An unstable reference to a scope-stack depth.  Invalidated by
363  /// pushes but not pops.
364  class iterator;
365
366  /// Returns an iterator pointing to the innermost EH scope.
367  iterator begin() const;
368
369  /// Returns an iterator pointing to the outermost EH scope.
370  iterator end() const;
371
372  /// Create a stable reference to the top of the EH stack.  The
373  /// returned reference is valid until that scope is popped off the
374  /// stack.
375  stable_iterator stable_begin() const {
376    return stable_iterator(EndOfBuffer - StartOfData);
377  }
378
379  /// Create a stable reference to the bottom of the EH stack.
380  static stable_iterator stable_end() {
381    return stable_iterator(0);
382  }
383
384  /// Translates an iterator into a stable_iterator.
385  stable_iterator stabilize(iterator it) const;
386
387  /// Finds the nearest cleanup enclosing the given iterator.
388  /// Returns stable_iterator::invalid() if there are no such cleanups.
389  stable_iterator getEnclosingEHCleanup(iterator it) const;
390
391  /// Turn a stable reference to a scope depth into a unstable pointer
392  /// to the EH stack.
393  iterator find(stable_iterator save) const;
394
395  /// Removes the cleanup pointed to by the given stable_iterator.
396  void removeCleanup(stable_iterator save);
397
398  /// Add a branch fixup to the current cleanup scope.
399  BranchFixup &addBranchFixup() {
400    assert(hasNormalCleanups() && "adding fixup in scope without cleanups");
401    BranchFixups.push_back(BranchFixup());
402    return BranchFixups.back();
403  }
404
405  unsigned getNumBranchFixups() const { return BranchFixups.size(); }
406  BranchFixup &getBranchFixup(unsigned I) {
407    assert(I < getNumBranchFixups());
408    return BranchFixups[I];
409  }
410
411  /// Pops lazily-removed fixups from the end of the list.  This
412  /// should only be called by procedures which have just popped a
413  /// cleanup or resolved one or more fixups.
414  void popNullFixups();
415
416  /// Clears the branch-fixups list.  This should only be called by
417  /// ResolveAllBranchFixups.
418  void clearFixups() { BranchFixups.clear(); }
419
420  /// Gets the next EH destination index.
421  unsigned getNextEHDestIndex() { return NextEHDestIndex++; }
422};
423
424/// CodeGenFunction - This class organizes the per-function state that is used
425/// while generating LLVM code.
426class CodeGenFunction : public BlockFunction {
427  CodeGenFunction(const CodeGenFunction&); // DO NOT IMPLEMENT
428  void operator=(const CodeGenFunction&);  // DO NOT IMPLEMENT
429
430  friend class CGCXXABI;
431public:
432  /// A jump destination is an abstract label, branching to which may
433  /// require a jump out through normal cleanups.
434  struct JumpDest {
435    JumpDest() : Block(0), ScopeDepth(), Index(0) {}
436    JumpDest(llvm::BasicBlock *Block,
437             EHScopeStack::stable_iterator Depth,
438             unsigned Index)
439      : Block(Block), ScopeDepth(Depth), Index(Index) {}
440
441    bool isValid() const { return Block != 0; }
442    llvm::BasicBlock *getBlock() const { return Block; }
443    EHScopeStack::stable_iterator getScopeDepth() const { return ScopeDepth; }
444    unsigned getDestIndex() const { return Index; }
445
446  private:
447    llvm::BasicBlock *Block;
448    EHScopeStack::stable_iterator ScopeDepth;
449    unsigned Index;
450  };
451
452  /// An unwind destination is an abstract label, branching to which
453  /// may require a jump out through EH cleanups.
454  struct UnwindDest {
455    UnwindDest() : Block(0), ScopeDepth(), Index(0) {}
456    UnwindDest(llvm::BasicBlock *Block,
457               EHScopeStack::stable_iterator Depth,
458               unsigned Index)
459      : Block(Block), ScopeDepth(Depth), Index(Index) {}
460
461    bool isValid() const { return Block != 0; }
462    llvm::BasicBlock *getBlock() const { return Block; }
463    EHScopeStack::stable_iterator getScopeDepth() const { return ScopeDepth; }
464    unsigned getDestIndex() const { return Index; }
465
466  private:
467    llvm::BasicBlock *Block;
468    EHScopeStack::stable_iterator ScopeDepth;
469    unsigned Index;
470  };
471
472  CodeGenModule &CGM;  // Per-module state.
473  const TargetInfo &Target;
474
475  typedef std::pair<llvm::Value *, llvm::Value *> ComplexPairTy;
476  CGBuilderTy Builder;
477
478  /// CurFuncDecl - Holds the Decl for the current function or ObjC method.
479  /// This excludes BlockDecls.
480  const Decl *CurFuncDecl;
481  /// CurCodeDecl - This is the inner-most code context, which includes blocks.
482  const Decl *CurCodeDecl;
483  const CGFunctionInfo *CurFnInfo;
484  QualType FnRetTy;
485  llvm::Function *CurFn;
486
487  /// CurGD - The GlobalDecl for the current function being compiled.
488  GlobalDecl CurGD;
489
490  /// ReturnBlock - Unified return block.
491  JumpDest ReturnBlock;
492
493  /// ReturnValue - The temporary alloca to hold the return value. This is null
494  /// iff the function has no return value.
495  llvm::Value *ReturnValue;
496
497  /// RethrowBlock - Unified rethrow block.
498  UnwindDest RethrowBlock;
499
500  /// AllocaInsertPoint - This is an instruction in the entry block before which
501  /// we prefer to insert allocas.
502  llvm::AssertingVH<llvm::Instruction> AllocaInsertPt;
503
504  // intptr_t, i32, i64
505  const llvm::IntegerType *IntPtrTy, *Int32Ty, *Int64Ty;
506  uint32_t LLVMPointerWidth;
507
508  bool Exceptions;
509  bool CatchUndefined;
510
511  /// \brief A mapping from NRVO variables to the flags used to indicate
512  /// when the NRVO has been applied to this variable.
513  llvm::DenseMap<const VarDecl *, llvm::Value *> NRVOFlags;
514
515  /// \brief A mapping from 'Save' expression in a conditional expression
516  /// to the IR for this expression. Used to implement IR gen. for Gnu
517  /// extension's missing LHS expression in a conditional operator expression.
518  llvm::DenseMap<const Expr *, llvm::Value *> ConditionalSaveExprs;
519  llvm::DenseMap<const Expr *, ComplexPairTy> ConditionalSaveComplexExprs;
520  llvm::DenseMap<const Expr *, LValue> ConditionalSaveLValueExprs;
521
522  EHScopeStack EHStack;
523
524  /// i32s containing the indexes of the cleanup destinations.
525  llvm::AllocaInst *NormalCleanupDest;
526  llvm::AllocaInst *EHCleanupDest;
527
528  unsigned NextCleanupDestIndex;
529
530  /// The exception slot.  All landing pads write the current
531  /// exception pointer into this alloca.
532  llvm::Value *ExceptionSlot;
533
534  /// Emits a landing pad for the current EH stack.
535  llvm::BasicBlock *EmitLandingPad();
536
537  llvm::BasicBlock *getInvokeDestImpl();
538
539public:
540  /// ObjCEHValueStack - Stack of Objective-C exception values, used for
541  /// rethrows.
542  llvm::SmallVector<llvm::Value*, 8> ObjCEHValueStack;
543
544  // A struct holding information about a finally block's IR
545  // generation.  For now, doesn't actually hold anything.
546  struct FinallyInfo {
547  };
548
549  FinallyInfo EnterFinallyBlock(const Stmt *Stmt,
550                                llvm::Constant *BeginCatchFn,
551                                llvm::Constant *EndCatchFn,
552                                llvm::Constant *RethrowFn);
553  void ExitFinallyBlock(FinallyInfo &FinallyInfo);
554
555  /// PushDestructorCleanup - Push a cleanup to call the
556  /// complete-object destructor of an object of the given type at the
557  /// given address.  Does nothing if T is not a C++ class type with a
558  /// non-trivial destructor.
559  void PushDestructorCleanup(QualType T, llvm::Value *Addr);
560
561  /// PushDestructorCleanup - Push a cleanup to call the
562  /// complete-object variant of the given destructor on the object at
563  /// the given address.
564  void PushDestructorCleanup(const CXXDestructorDecl *Dtor,
565                             llvm::Value *Addr);
566
567  /// PopCleanupBlock - Will pop the cleanup entry on the stack and
568  /// process all branch fixups.
569  void PopCleanupBlock(bool FallThroughIsBranchThrough = false);
570
571  /// DeactivateCleanupBlock - Deactivates the given cleanup block.
572  /// The block cannot be reactivated.  Pops it if it's the top of the
573  /// stack.
574  void DeactivateCleanupBlock(EHScopeStack::stable_iterator Cleanup);
575
576  /// ActivateCleanupBlock - Activates an initially-inactive cleanup.
577  /// Cannot be used to resurrect a deactivated cleanup.
578  void ActivateCleanupBlock(EHScopeStack::stable_iterator Cleanup);
579
580  /// \brief Enters a new scope for capturing cleanups, all of which
581  /// will be executed once the scope is exited.
582  class RunCleanupsScope {
583    CodeGenFunction& CGF;
584    EHScopeStack::stable_iterator CleanupStackDepth;
585    bool OldDidCallStackSave;
586    bool PerformCleanup;
587
588    RunCleanupsScope(const RunCleanupsScope &); // DO NOT IMPLEMENT
589    RunCleanupsScope &operator=(const RunCleanupsScope &); // DO NOT IMPLEMENT
590
591  public:
592    /// \brief Enter a new cleanup scope.
593    explicit RunCleanupsScope(CodeGenFunction &CGF)
594      : CGF(CGF), PerformCleanup(true)
595    {
596      CleanupStackDepth = CGF.EHStack.stable_begin();
597      OldDidCallStackSave = CGF.DidCallStackSave;
598      CGF.DidCallStackSave = false;
599    }
600
601    /// \brief Exit this cleanup scope, emitting any accumulated
602    /// cleanups.
603    ~RunCleanupsScope() {
604      if (PerformCleanup) {
605        CGF.DidCallStackSave = OldDidCallStackSave;
606        CGF.PopCleanupBlocks(CleanupStackDepth);
607      }
608    }
609
610    /// \brief Determine whether this scope requires any cleanups.
611    bool requiresCleanups() const {
612      return CGF.EHStack.stable_begin() != CleanupStackDepth;
613    }
614
615    /// \brief Force the emission of cleanups now, instead of waiting
616    /// until this object is destroyed.
617    void ForceCleanup() {
618      assert(PerformCleanup && "Already forced cleanup");
619      CGF.DidCallStackSave = OldDidCallStackSave;
620      CGF.PopCleanupBlocks(CleanupStackDepth);
621      PerformCleanup = false;
622    }
623  };
624
625
626  /// PopCleanupBlocks - Takes the old cleanup stack size and emits
627  /// the cleanup blocks that have been added.
628  void PopCleanupBlocks(EHScopeStack::stable_iterator OldCleanupStackSize);
629
630  void ResolveBranchFixups(llvm::BasicBlock *Target);
631
632  /// The given basic block lies in the current EH scope, but may be a
633  /// target of a potentially scope-crossing jump; get a stable handle
634  /// to which we can perform this jump later.
635  JumpDest getJumpDestInCurrentScope(llvm::BasicBlock *Target) {
636    return JumpDest(Target,
637                    EHStack.getInnermostNormalCleanup(),
638                    NextCleanupDestIndex++);
639  }
640
641  /// The given basic block lies in the current EH scope, but may be a
642  /// target of a potentially scope-crossing jump; get a stable handle
643  /// to which we can perform this jump later.
644  JumpDest getJumpDestInCurrentScope(const char *Name = 0) {
645    return getJumpDestInCurrentScope(createBasicBlock(Name));
646  }
647
648  /// EmitBranchThroughCleanup - Emit a branch from the current insert
649  /// block through the normal cleanup handling code (if any) and then
650  /// on to \arg Dest.
651  void EmitBranchThroughCleanup(JumpDest Dest);
652
653  /// EmitBranchThroughEHCleanup - Emit a branch from the current
654  /// insert block through the EH cleanup handling code (if any) and
655  /// then on to \arg Dest.
656  void EmitBranchThroughEHCleanup(UnwindDest Dest);
657
658  /// getRethrowDest - Returns the unified outermost-scope rethrow
659  /// destination.
660  UnwindDest getRethrowDest();
661
662  /// BeginConditionalBranch - Should be called before a conditional part of an
663  /// expression is emitted. For example, before the RHS of the expression below
664  /// is emitted:
665  ///
666  /// b && f(T());
667  ///
668  /// This is used to make sure that any temporaries created in the conditional
669  /// branch are only destroyed if the branch is taken.
670  void BeginConditionalBranch() {
671    ++ConditionalBranchLevel;
672  }
673
674  /// EndConditionalBranch - Should be called after a conditional part of an
675  /// expression has been emitted.
676  void EndConditionalBranch() {
677    assert(ConditionalBranchLevel != 0 &&
678           "Conditional branch mismatch!");
679
680    --ConditionalBranchLevel;
681  }
682
683  /// isInConditionalBranch - Return true if we're currently emitting
684  /// one branch or the other of a conditional expression.
685  bool isInConditionalBranch() const { return ConditionalBranchLevel != 0; }
686
687  /// getByrefValueFieldNumber - Given a declaration, returns the LLVM field
688  /// number that holds the value.
689  unsigned getByRefValueLLVMField(const ValueDecl *VD) const;
690
691private:
692  CGDebugInfo *DebugInfo;
693
694  /// IndirectBranch - The first time an indirect goto is seen we create a block
695  /// with an indirect branch.  Every time we see the address of a label taken,
696  /// we add the label to the indirect goto.  Every subsequent indirect goto is
697  /// codegen'd as a jump to the IndirectBranch's basic block.
698  llvm::IndirectBrInst *IndirectBranch;
699
700  /// LocalDeclMap - This keeps track of the LLVM allocas or globals for local C
701  /// decls.
702  llvm::DenseMap<const Decl*, llvm::Value*> LocalDeclMap;
703
704  /// LabelMap - This keeps track of the LLVM basic block for each C label.
705  llvm::DenseMap<const LabelStmt*, JumpDest> LabelMap;
706
707  // BreakContinueStack - This keeps track of where break and continue
708  // statements should jump to.
709  struct BreakContinue {
710    BreakContinue(JumpDest Break, JumpDest Continue)
711      : BreakBlock(Break), ContinueBlock(Continue) {}
712
713    JumpDest BreakBlock;
714    JumpDest ContinueBlock;
715  };
716  llvm::SmallVector<BreakContinue, 8> BreakContinueStack;
717
718  /// SwitchInsn - This is nearest current switch instruction. It is null if if
719  /// current context is not in a switch.
720  llvm::SwitchInst *SwitchInsn;
721
722  /// CaseRangeBlock - This block holds if condition check for last case
723  /// statement range in current switch instruction.
724  llvm::BasicBlock *CaseRangeBlock;
725
726  // VLASizeMap - This keeps track of the associated size for each VLA type.
727  // We track this by the size expression rather than the type itself because
728  // in certain situations, like a const qualifier applied to an VLA typedef,
729  // multiple VLA types can share the same size expression.
730  // FIXME: Maybe this could be a stack of maps that is pushed/popped as we
731  // enter/leave scopes.
732  llvm::DenseMap<const Expr*, llvm::Value*> VLASizeMap;
733
734  /// DidCallStackSave - Whether llvm.stacksave has been called. Used to avoid
735  /// calling llvm.stacksave for multiple VLAs in the same scope.
736  bool DidCallStackSave;
737
738  /// A block containing a single 'unreachable' instruction.  Created
739  /// lazily by getUnreachableBlock().
740  llvm::BasicBlock *UnreachableBlock;
741
742  /// CXXThisDecl - When generating code for a C++ member function,
743  /// this will hold the implicit 'this' declaration.
744  ImplicitParamDecl *CXXThisDecl;
745  llvm::Value *CXXThisValue;
746
747  /// CXXVTTDecl - When generating code for a base object constructor or
748  /// base object destructor with virtual bases, this will hold the implicit
749  /// VTT parameter.
750  ImplicitParamDecl *CXXVTTDecl;
751  llvm::Value *CXXVTTValue;
752
753  /// ConditionalBranchLevel - Contains the nesting level of the current
754  /// conditional branch. This is used so that we know if a temporary should be
755  /// destroyed conditionally.
756  unsigned ConditionalBranchLevel;
757
758
759  /// ByrefValueInfoMap - For each __block variable, contains a pair of the LLVM
760  /// type as well as the field number that contains the actual data.
761  llvm::DenseMap<const ValueDecl *, std::pair<const llvm::Type *,
762                                              unsigned> > ByRefValueInfo;
763
764  llvm::BasicBlock *TerminateLandingPad;
765  llvm::BasicBlock *TerminateHandler;
766  llvm::BasicBlock *TrapBB;
767
768public:
769  CodeGenFunction(CodeGenModule &cgm);
770
771  CodeGenTypes &getTypes() const { return CGM.getTypes(); }
772  ASTContext &getContext() const;
773  CGDebugInfo *getDebugInfo() { return DebugInfo; }
774
775  /// Returns a pointer to the function's exception object slot, which
776  /// is assigned in every landing pad.
777  llvm::Value *getExceptionSlot();
778
779  llvm::Value *getNormalCleanupDestSlot();
780  llvm::Value *getEHCleanupDestSlot();
781
782  llvm::BasicBlock *getUnreachableBlock() {
783    if (!UnreachableBlock) {
784      UnreachableBlock = createBasicBlock("unreachable");
785      new llvm::UnreachableInst(getLLVMContext(), UnreachableBlock);
786    }
787    return UnreachableBlock;
788  }
789
790  llvm::BasicBlock *getInvokeDest() {
791    if (!EHStack.requiresLandingPad()) return 0;
792    return getInvokeDestImpl();
793  }
794
795  llvm::LLVMContext &getLLVMContext() { return VMContext; }
796
797  //===--------------------------------------------------------------------===//
798  //                                  Objective-C
799  //===--------------------------------------------------------------------===//
800
801  void GenerateObjCMethod(const ObjCMethodDecl *OMD);
802
803  void StartObjCMethod(const ObjCMethodDecl *MD,
804                       const ObjCContainerDecl *CD);
805
806  /// GenerateObjCGetter - Synthesize an Objective-C property getter function.
807  void GenerateObjCGetter(ObjCImplementationDecl *IMP,
808                          const ObjCPropertyImplDecl *PID);
809  void GenerateObjCCtorDtorMethod(ObjCImplementationDecl *IMP,
810                                  ObjCMethodDecl *MD, bool ctor);
811
812  /// GenerateObjCSetter - Synthesize an Objective-C property setter function
813  /// for the given property.
814  void GenerateObjCSetter(ObjCImplementationDecl *IMP,
815                          const ObjCPropertyImplDecl *PID);
816  bool IndirectObjCSetterArg(const CGFunctionInfo &FI);
817  bool IvarTypeWithAggrGCObjects(QualType Ty);
818
819  //===--------------------------------------------------------------------===//
820  //                                  Block Bits
821  //===--------------------------------------------------------------------===//
822
823  llvm::Value *BuildBlockLiteralTmp(const BlockExpr *);
824  llvm::Constant *BuildDescriptorBlockDecl(const BlockExpr *,
825                                           const CGBlockInfo &Info,
826                                           const llvm::StructType *,
827                                           llvm::Constant *BlockVarLayout,
828                                           std::vector<HelperInfo> *);
829
830  llvm::Function *GenerateBlockFunction(GlobalDecl GD,
831                                        const BlockExpr *BExpr,
832                                        CGBlockInfo &Info,
833                                        const Decl *OuterFuncDecl,
834                                        llvm::Constant *& BlockVarLayout,
835                                  llvm::DenseMap<const Decl*, llvm::Value*> ldm);
836
837  llvm::Value *LoadBlockStruct();
838
839  void AllocateBlockCXXThisPointer(const CXXThisExpr *E);
840  void AllocateBlockDecl(const BlockDeclRefExpr *E);
841  llvm::Value *GetAddrOfBlockDecl(const BlockDeclRefExpr *E) {
842    return GetAddrOfBlockDecl(E->getDecl(), E->isByRef());
843  }
844  llvm::Value *GetAddrOfBlockDecl(const ValueDecl *D, bool ByRef);
845  const llvm::Type *BuildByRefType(const ValueDecl *D);
846
847  void GenerateCode(GlobalDecl GD, llvm::Function *Fn);
848  void StartFunction(GlobalDecl GD, QualType RetTy,
849                     llvm::Function *Fn,
850                     const FunctionArgList &Args,
851                     SourceLocation StartLoc);
852
853  void EmitConstructorBody(FunctionArgList &Args);
854  void EmitDestructorBody(FunctionArgList &Args);
855  void EmitFunctionBody(FunctionArgList &Args);
856
857  /// EmitReturnBlock - Emit the unified return block, trying to avoid its
858  /// emission when possible.
859  void EmitReturnBlock();
860
861  /// FinishFunction - Complete IR generation of the current function. It is
862  /// legal to call this function even if there is no current insertion point.
863  void FinishFunction(SourceLocation EndLoc=SourceLocation());
864
865  /// GenerateThunk - Generate a thunk for the given method.
866  void GenerateThunk(llvm::Function *Fn, GlobalDecl GD, const ThunkInfo &Thunk);
867
868  void EmitCtorPrologue(const CXXConstructorDecl *CD, CXXCtorType Type,
869                        FunctionArgList &Args);
870
871  /// InitializeVTablePointer - Initialize the vtable pointer of the given
872  /// subobject.
873  ///
874  void InitializeVTablePointer(BaseSubobject Base,
875                               const CXXRecordDecl *NearestVBase,
876                               uint64_t OffsetFromNearestVBase,
877                               llvm::Constant *VTable,
878                               const CXXRecordDecl *VTableClass);
879
880  typedef llvm::SmallPtrSet<const CXXRecordDecl *, 4> VisitedVirtualBasesSetTy;
881  void InitializeVTablePointers(BaseSubobject Base,
882                                const CXXRecordDecl *NearestVBase,
883                                uint64_t OffsetFromNearestVBase,
884                                bool BaseIsNonVirtualPrimaryBase,
885                                llvm::Constant *VTable,
886                                const CXXRecordDecl *VTableClass,
887                                VisitedVirtualBasesSetTy& VBases);
888
889  void InitializeVTablePointers(const CXXRecordDecl *ClassDecl);
890
891  /// GetVTablePtr - Return the Value of the vtable pointer member pointed
892  /// to by This.
893  llvm::Value *GetVTablePtr(llvm::Value *This, const llvm::Type *Ty);
894
895  /// EnterDtorCleanups - Enter the cleanups necessary to complete the
896  /// given phase of destruction for a destructor.  The end result
897  /// should call destructors on members and base classes in reverse
898  /// order of their construction.
899  void EnterDtorCleanups(const CXXDestructorDecl *Dtor, CXXDtorType Type);
900
901  /// ShouldInstrumentFunction - Return true if the current function should be
902  /// instrumented with __cyg_profile_func_* calls
903  bool ShouldInstrumentFunction();
904
905  /// EmitFunctionInstrumentation - Emit LLVM code to call the specified
906  /// instrumentation function with the current function and the call site, if
907  /// function instrumentation is enabled.
908  void EmitFunctionInstrumentation(const char *Fn);
909
910  /// EmitFunctionProlog - Emit the target specific LLVM code to load the
911  /// arguments for the given function. This is also responsible for naming the
912  /// LLVM function arguments.
913  void EmitFunctionProlog(const CGFunctionInfo &FI,
914                          llvm::Function *Fn,
915                          const FunctionArgList &Args);
916
917  /// EmitFunctionEpilog - Emit the target specific LLVM code to return the
918  /// given temporary.
919  void EmitFunctionEpilog(const CGFunctionInfo &FI);
920
921  /// EmitStartEHSpec - Emit the start of the exception spec.
922  void EmitStartEHSpec(const Decl *D);
923
924  /// EmitEndEHSpec - Emit the end of the exception spec.
925  void EmitEndEHSpec(const Decl *D);
926
927  /// getTerminateLandingPad - Return a landing pad that just calls terminate.
928  llvm::BasicBlock *getTerminateLandingPad();
929
930  /// getTerminateHandler - Return a handler (not a landing pad, just
931  /// a catch handler) that just calls terminate.  This is used when
932  /// a terminate scope encloses a try.
933  llvm::BasicBlock *getTerminateHandler();
934
935  const llvm::Type *ConvertTypeForMem(QualType T);
936  const llvm::Type *ConvertType(QualType T);
937  const llvm::Type *ConvertType(const TypeDecl *T) {
938    return ConvertType(getContext().getTypeDeclType(T));
939  }
940
941  /// LoadObjCSelf - Load the value of self. This function is only valid while
942  /// generating code for an Objective-C method.
943  llvm::Value *LoadObjCSelf();
944
945  /// TypeOfSelfObject - Return type of object that this self represents.
946  QualType TypeOfSelfObject();
947
948  /// hasAggregateLLVMType - Return true if the specified AST type will map into
949  /// an aggregate LLVM type or is void.
950  static bool hasAggregateLLVMType(QualType T);
951
952  /// createBasicBlock - Create an LLVM basic block.
953  llvm::BasicBlock *createBasicBlock(const char *Name="",
954                                     llvm::Function *Parent=0,
955                                     llvm::BasicBlock *InsertBefore=0) {
956#ifdef NDEBUG
957    return llvm::BasicBlock::Create(VMContext, "", Parent, InsertBefore);
958#else
959    return llvm::BasicBlock::Create(VMContext, Name, Parent, InsertBefore);
960#endif
961  }
962
963  /// getBasicBlockForLabel - Return the LLVM basicblock that the specified
964  /// label maps to.
965  JumpDest getJumpDestForLabel(const LabelStmt *S);
966
967  /// SimplifyForwardingBlocks - If the given basic block is only a branch to
968  /// another basic block, simplify it. This assumes that no other code could
969  /// potentially reference the basic block.
970  void SimplifyForwardingBlocks(llvm::BasicBlock *BB);
971
972  /// EmitBlock - Emit the given block \arg BB and set it as the insert point,
973  /// adding a fall-through branch from the current insert block if
974  /// necessary. It is legal to call this function even if there is no current
975  /// insertion point.
976  ///
977  /// IsFinished - If true, indicates that the caller has finished emitting
978  /// branches to the given block and does not expect to emit code into it. This
979  /// means the block can be ignored if it is unreachable.
980  void EmitBlock(llvm::BasicBlock *BB, bool IsFinished=false);
981
982  /// EmitBranch - Emit a branch to the specified basic block from the current
983  /// insert block, taking care to avoid creation of branches from dummy
984  /// blocks. It is legal to call this function even if there is no current
985  /// insertion point.
986  ///
987  /// This function clears the current insertion point. The caller should follow
988  /// calls to this function with calls to Emit*Block prior to generation new
989  /// code.
990  void EmitBranch(llvm::BasicBlock *Block);
991
992  /// HaveInsertPoint - True if an insertion point is defined. If not, this
993  /// indicates that the current code being emitted is unreachable.
994  bool HaveInsertPoint() const {
995    return Builder.GetInsertBlock() != 0;
996  }
997
998  /// EnsureInsertPoint - Ensure that an insertion point is defined so that
999  /// emitted IR has a place to go. Note that by definition, if this function
1000  /// creates a block then that block is unreachable; callers may do better to
1001  /// detect when no insertion point is defined and simply skip IR generation.
1002  void EnsureInsertPoint() {
1003    if (!HaveInsertPoint())
1004      EmitBlock(createBasicBlock());
1005  }
1006
1007  /// ErrorUnsupported - Print out an error that codegen doesn't support the
1008  /// specified stmt yet.
1009  void ErrorUnsupported(const Stmt *S, const char *Type,
1010                        bool OmitOnError=false);
1011
1012  //===--------------------------------------------------------------------===//
1013  //                                  Helpers
1014  //===--------------------------------------------------------------------===//
1015
1016  LValue MakeAddrLValue(llvm::Value *V, QualType T, unsigned Alignment = 0) {
1017    return LValue::MakeAddr(V, T, Alignment, getContext(),
1018                            CGM.getTBAAInfo(T));
1019  }
1020
1021  /// CreateTempAlloca - This creates a alloca and inserts it into the entry
1022  /// block. The caller is responsible for setting an appropriate alignment on
1023  /// the alloca.
1024  llvm::AllocaInst *CreateTempAlloca(const llvm::Type *Ty,
1025                                     const llvm::Twine &Name = "tmp");
1026
1027  /// InitTempAlloca - Provide an initial value for the given alloca.
1028  void InitTempAlloca(llvm::AllocaInst *Alloca, llvm::Value *Value);
1029
1030  /// CreateIRTemp - Create a temporary IR object of the given type, with
1031  /// appropriate alignment. This routine should only be used when an temporary
1032  /// value needs to be stored into an alloca (for example, to avoid explicit
1033  /// PHI construction), but the type is the IR type, not the type appropriate
1034  /// for storing in memory.
1035  llvm::AllocaInst *CreateIRTemp(QualType T, const llvm::Twine &Name = "tmp");
1036
1037  /// CreateMemTemp - Create a temporary memory object of the given type, with
1038  /// appropriate alignment.
1039  llvm::AllocaInst *CreateMemTemp(QualType T, const llvm::Twine &Name = "tmp");
1040
1041  /// CreateAggTemp - Create a temporary memory object for the given
1042  /// aggregate type.
1043  AggValueSlot CreateAggTemp(QualType T, const llvm::Twine &Name = "tmp") {
1044    return AggValueSlot::forAddr(CreateMemTemp(T, Name), false, false);
1045  }
1046
1047  /// EvaluateExprAsBool - Perform the usual unary conversions on the specified
1048  /// expression and compare the result against zero, returning an Int1Ty value.
1049  llvm::Value *EvaluateExprAsBool(const Expr *E);
1050
1051  /// EmitAnyExpr - Emit code to compute the specified expression which can have
1052  /// any type.  The result is returned as an RValue struct.  If this is an
1053  /// aggregate expression, the aggloc/agglocvolatile arguments indicate where
1054  /// the result should be returned.
1055  ///
1056  /// \param IgnoreResult - True if the resulting value isn't used.
1057  RValue EmitAnyExpr(const Expr *E,
1058                     AggValueSlot AggSlot = AggValueSlot::ignored(),
1059                     bool IgnoreResult = false);
1060
1061  // EmitVAListRef - Emit a "reference" to a va_list; this is either the address
1062  // or the value of the expression, depending on how va_list is defined.
1063  llvm::Value *EmitVAListRef(const Expr *E);
1064
1065  /// EmitAnyExprToTemp - Similary to EmitAnyExpr(), however, the result will
1066  /// always be accessible even if no aggregate location is provided.
1067  RValue EmitAnyExprToTemp(const Expr *E);
1068
1069  /// EmitsAnyExprToMem - Emits the code necessary to evaluate an
1070  /// arbitrary expression into the given memory location.
1071  void EmitAnyExprToMem(const Expr *E, llvm::Value *Location,
1072                        bool IsLocationVolatile,
1073                        bool IsInitializer);
1074
1075  /// EmitAggregateCopy - Emit an aggrate copy.
1076  ///
1077  /// \param isVolatile - True iff either the source or the destination is
1078  /// volatile.
1079  void EmitAggregateCopy(llvm::Value *DestPtr, llvm::Value *SrcPtr,
1080                         QualType EltTy, bool isVolatile=false);
1081
1082  /// StartBlock - Start new block named N. If insert block is a dummy block
1083  /// then reuse it.
1084  void StartBlock(const char *N);
1085
1086  /// GetAddrOfStaticLocalVar - Return the address of a static local variable.
1087  llvm::Constant *GetAddrOfStaticLocalVar(const VarDecl *BVD) {
1088    return cast<llvm::Constant>(GetAddrOfLocalVar(BVD));
1089  }
1090
1091  /// GetAddrOfLocalVar - Return the address of a local variable.
1092  llvm::Value *GetAddrOfLocalVar(const VarDecl *VD) {
1093    llvm::Value *Res = LocalDeclMap[VD];
1094    assert(Res && "Invalid argument to GetAddrOfLocalVar(), no decl!");
1095    return Res;
1096  }
1097
1098  /// getAccessedFieldNo - Given an encoded value and a result number, return
1099  /// the input field number being accessed.
1100  static unsigned getAccessedFieldNo(unsigned Idx, const llvm::Constant *Elts);
1101
1102  llvm::BlockAddress *GetAddrOfLabel(const LabelStmt *L);
1103  llvm::BasicBlock *GetIndirectGotoBlock();
1104
1105  /// EmitNullInitialization - Generate code to set a value of the given type to
1106  /// null, If the type contains data member pointers, they will be initialized
1107  /// to -1 in accordance with the Itanium C++ ABI.
1108  void EmitNullInitialization(llvm::Value *DestPtr, QualType Ty);
1109
1110  // EmitVAArg - Generate code to get an argument from the passed in pointer
1111  // and update it accordingly. The return value is a pointer to the argument.
1112  // FIXME: We should be able to get rid of this method and use the va_arg
1113  // instruction in LLVM instead once it works well enough.
1114  llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty);
1115
1116  /// EmitVLASize - Generate code for any VLA size expressions that might occur
1117  /// in a variably modified type. If Ty is a VLA, will return the value that
1118  /// corresponds to the size in bytes of the VLA type. Will return 0 otherwise.
1119  ///
1120  /// This function can be called with a null (unreachable) insert point.
1121  llvm::Value *EmitVLASize(QualType Ty);
1122
1123  // GetVLASize - Returns an LLVM value that corresponds to the size in bytes
1124  // of a variable length array type.
1125  llvm::Value *GetVLASize(const VariableArrayType *);
1126
1127  /// LoadCXXThis - Load the value of 'this'. This function is only valid while
1128  /// generating code for an C++ member function.
1129  llvm::Value *LoadCXXThis() {
1130    assert(CXXThisValue && "no 'this' value for this function");
1131    return CXXThisValue;
1132  }
1133
1134  /// LoadCXXVTT - Load the VTT parameter to base constructors/destructors have
1135  /// virtual bases.
1136  llvm::Value *LoadCXXVTT() {
1137    assert(CXXVTTValue && "no VTT value for this function");
1138    return CXXVTTValue;
1139  }
1140
1141  /// GetAddressOfBaseOfCompleteClass - Convert the given pointer to a
1142  /// complete class to the given direct base.
1143  llvm::Value *
1144  GetAddressOfDirectBaseInCompleteClass(llvm::Value *Value,
1145                                        const CXXRecordDecl *Derived,
1146                                        const CXXRecordDecl *Base,
1147                                        bool BaseIsVirtual);
1148
1149  /// GetAddressOfBaseClass - This function will add the necessary delta to the
1150  /// load of 'this' and returns address of the base class.
1151  llvm::Value *GetAddressOfBaseClass(llvm::Value *Value,
1152                                     const CXXRecordDecl *Derived,
1153                                     CastExpr::path_const_iterator PathBegin,
1154                                     CastExpr::path_const_iterator PathEnd,
1155                                     bool NullCheckValue);
1156
1157  llvm::Value *GetAddressOfDerivedClass(llvm::Value *Value,
1158                                        const CXXRecordDecl *Derived,
1159                                        CastExpr::path_const_iterator PathBegin,
1160                                        CastExpr::path_const_iterator PathEnd,
1161                                        bool NullCheckValue);
1162
1163  llvm::Value *GetVirtualBaseClassOffset(llvm::Value *This,
1164                                         const CXXRecordDecl *ClassDecl,
1165                                         const CXXRecordDecl *BaseClassDecl);
1166
1167  void EmitDelegateCXXConstructorCall(const CXXConstructorDecl *Ctor,
1168                                      CXXCtorType CtorType,
1169                                      const FunctionArgList &Args);
1170  void EmitCXXConstructorCall(const CXXConstructorDecl *D, CXXCtorType Type,
1171                              bool ForVirtualBase, llvm::Value *This,
1172                              CallExpr::const_arg_iterator ArgBeg,
1173                              CallExpr::const_arg_iterator ArgEnd);
1174
1175  void EmitSynthesizedCXXCopyCtorCall(const CXXConstructorDecl *D,
1176                              llvm::Value *This, llvm::Value *Src,
1177                              CallExpr::const_arg_iterator ArgBeg,
1178                              CallExpr::const_arg_iterator ArgEnd);
1179
1180  void EmitCXXAggrConstructorCall(const CXXConstructorDecl *D,
1181                                  const ConstantArrayType *ArrayTy,
1182                                  llvm::Value *ArrayPtr,
1183                                  CallExpr::const_arg_iterator ArgBeg,
1184                                  CallExpr::const_arg_iterator ArgEnd,
1185                                  bool ZeroInitialization = false);
1186
1187  void EmitCXXAggrConstructorCall(const CXXConstructorDecl *D,
1188                                  llvm::Value *NumElements,
1189                                  llvm::Value *ArrayPtr,
1190                                  CallExpr::const_arg_iterator ArgBeg,
1191                                  CallExpr::const_arg_iterator ArgEnd,
1192                                  bool ZeroInitialization = false);
1193
1194  void EmitCXXAggrDestructorCall(const CXXDestructorDecl *D,
1195                                 const ArrayType *Array,
1196                                 llvm::Value *This);
1197
1198  void EmitCXXAggrDestructorCall(const CXXDestructorDecl *D,
1199                                 llvm::Value *NumElements,
1200                                 llvm::Value *This);
1201
1202  llvm::Function *GenerateCXXAggrDestructorHelper(const CXXDestructorDecl *D,
1203                                                  const ArrayType *Array,
1204                                                  llvm::Value *This);
1205
1206  void EmitCXXDestructorCall(const CXXDestructorDecl *D, CXXDtorType Type,
1207                             bool ForVirtualBase, llvm::Value *This);
1208
1209  void EmitNewArrayInitializer(const CXXNewExpr *E, llvm::Value *NewPtr,
1210                               llvm::Value *NumElements);
1211
1212  void EmitCXXTemporary(const CXXTemporary *Temporary, llvm::Value *Ptr);
1213
1214  llvm::Value *EmitCXXNewExpr(const CXXNewExpr *E);
1215  void EmitCXXDeleteExpr(const CXXDeleteExpr *E);
1216
1217  void EmitDeleteCall(const FunctionDecl *DeleteFD, llvm::Value *Ptr,
1218                      QualType DeleteTy);
1219
1220  llvm::Value* EmitCXXTypeidExpr(const CXXTypeidExpr *E);
1221  llvm::Value *EmitDynamicCast(llvm::Value *V, const CXXDynamicCastExpr *DCE);
1222
1223  void EmitCheck(llvm::Value *, unsigned Size);
1224
1225  llvm::Value *EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
1226                                       bool isInc, bool isPre);
1227  ComplexPairTy EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
1228                                         bool isInc, bool isPre);
1229  //===--------------------------------------------------------------------===//
1230  //                            Declaration Emission
1231  //===--------------------------------------------------------------------===//
1232
1233  /// EmitDecl - Emit a declaration.
1234  ///
1235  /// This function can be called with a null (unreachable) insert point.
1236  void EmitDecl(const Decl &D);
1237
1238  /// EmitVarDecl - Emit a local variable declaration.
1239  ///
1240  /// This function can be called with a null (unreachable) insert point.
1241  void EmitVarDecl(const VarDecl &D);
1242
1243  typedef void SpecialInitFn(CodeGenFunction &Init, const VarDecl &D,
1244                             llvm::Value *Address);
1245
1246  /// EmitAutoVarDecl - Emit an auto variable declaration.
1247  ///
1248  /// This function can be called with a null (unreachable) insert point.
1249  void EmitAutoVarDecl(const VarDecl &D, SpecialInitFn *SpecialInit = 0);
1250
1251  void EmitStaticVarDecl(const VarDecl &D,
1252                         llvm::GlobalValue::LinkageTypes Linkage);
1253
1254  /// EmitParmDecl - Emit a ParmVarDecl or an ImplicitParamDecl.
1255  void EmitParmDecl(const VarDecl &D, llvm::Value *Arg);
1256
1257  //===--------------------------------------------------------------------===//
1258  //                             Statement Emission
1259  //===--------------------------------------------------------------------===//
1260
1261  /// EmitStopPoint - Emit a debug stoppoint if we are emitting debug info.
1262  void EmitStopPoint(const Stmt *S);
1263
1264  /// EmitStmt - Emit the code for the statement \arg S. It is legal to call
1265  /// this function even if there is no current insertion point.
1266  ///
1267  /// This function may clear the current insertion point; callers should use
1268  /// EnsureInsertPoint if they wish to subsequently generate code without first
1269  /// calling EmitBlock, EmitBranch, or EmitStmt.
1270  void EmitStmt(const Stmt *S);
1271
1272  /// EmitSimpleStmt - Try to emit a "simple" statement which does not
1273  /// necessarily require an insertion point or debug information; typically
1274  /// because the statement amounts to a jump or a container of other
1275  /// statements.
1276  ///
1277  /// \return True if the statement was handled.
1278  bool EmitSimpleStmt(const Stmt *S);
1279
1280  RValue EmitCompoundStmt(const CompoundStmt &S, bool GetLast = false,
1281                          AggValueSlot AVS = AggValueSlot::ignored());
1282
1283  /// EmitLabel - Emit the block for the given label. It is legal to call this
1284  /// function even if there is no current insertion point.
1285  void EmitLabel(const LabelStmt &S); // helper for EmitLabelStmt.
1286
1287  void EmitLabelStmt(const LabelStmt &S);
1288  void EmitGotoStmt(const GotoStmt &S);
1289  void EmitIndirectGotoStmt(const IndirectGotoStmt &S);
1290  void EmitIfStmt(const IfStmt &S);
1291  void EmitWhileStmt(const WhileStmt &S);
1292  void EmitDoStmt(const DoStmt &S);
1293  void EmitForStmt(const ForStmt &S);
1294  void EmitReturnStmt(const ReturnStmt &S);
1295  void EmitDeclStmt(const DeclStmt &S);
1296  void EmitBreakStmt(const BreakStmt &S);
1297  void EmitContinueStmt(const ContinueStmt &S);
1298  void EmitSwitchStmt(const SwitchStmt &S);
1299  void EmitDefaultStmt(const DefaultStmt &S);
1300  void EmitCaseStmt(const CaseStmt &S);
1301  void EmitCaseStmtRange(const CaseStmt &S);
1302  void EmitAsmStmt(const AsmStmt &S);
1303
1304  void EmitObjCForCollectionStmt(const ObjCForCollectionStmt &S);
1305  void EmitObjCAtTryStmt(const ObjCAtTryStmt &S);
1306  void EmitObjCAtThrowStmt(const ObjCAtThrowStmt &S);
1307  void EmitObjCAtSynchronizedStmt(const ObjCAtSynchronizedStmt &S);
1308
1309  llvm::Constant *getUnwindResumeOrRethrowFn();
1310  void EnterCXXTryStmt(const CXXTryStmt &S, bool IsFnTryBlock = false);
1311  void ExitCXXTryStmt(const CXXTryStmt &S, bool IsFnTryBlock = false);
1312
1313  void EmitCXXTryStmt(const CXXTryStmt &S);
1314
1315  //===--------------------------------------------------------------------===//
1316  //                         LValue Expression Emission
1317  //===--------------------------------------------------------------------===//
1318
1319  /// GetUndefRValue - Get an appropriate 'undef' rvalue for the given type.
1320  RValue GetUndefRValue(QualType Ty);
1321
1322  /// EmitUnsupportedRValue - Emit a dummy r-value using the type of E
1323  /// and issue an ErrorUnsupported style diagnostic (using the
1324  /// provided Name).
1325  RValue EmitUnsupportedRValue(const Expr *E,
1326                               const char *Name);
1327
1328  /// EmitUnsupportedLValue - Emit a dummy l-value using the type of E and issue
1329  /// an ErrorUnsupported style diagnostic (using the provided Name).
1330  LValue EmitUnsupportedLValue(const Expr *E,
1331                               const char *Name);
1332
1333  /// EmitLValue - Emit code to compute a designator that specifies the location
1334  /// of the expression.
1335  ///
1336  /// This can return one of two things: a simple address or a bitfield
1337  /// reference.  In either case, the LLVM Value* in the LValue structure is
1338  /// guaranteed to be an LLVM pointer type.
1339  ///
1340  /// If this returns a bitfield reference, nothing about the pointee type of
1341  /// the LLVM value is known: For example, it may not be a pointer to an
1342  /// integer.
1343  ///
1344  /// If this returns a normal address, and if the lvalue's C type is fixed
1345  /// size, this method guarantees that the returned pointer type will point to
1346  /// an LLVM type of the same size of the lvalue's type.  If the lvalue has a
1347  /// variable length type, this is not possible.
1348  ///
1349  LValue EmitLValue(const Expr *E);
1350
1351  /// EmitCheckedLValue - Same as EmitLValue but additionally we generate
1352  /// checking code to guard against undefined behavior.  This is only
1353  /// suitable when we know that the address will be used to access the
1354  /// object.
1355  LValue EmitCheckedLValue(const Expr *E);
1356
1357  /// EmitToMemory - Change a scalar value from its value
1358  /// representation to its in-memory representation.
1359  llvm::Value *EmitToMemory(llvm::Value *Value, QualType Ty);
1360
1361  /// EmitFromMemory - Change a scalar value from its memory
1362  /// representation to its value representation.
1363  llvm::Value *EmitFromMemory(llvm::Value *Value, QualType Ty);
1364
1365  /// EmitLoadOfScalar - Load a scalar value from an address, taking
1366  /// care to appropriately convert from the memory representation to
1367  /// the LLVM value representation.
1368  llvm::Value *EmitLoadOfScalar(llvm::Value *Addr, bool Volatile,
1369                                unsigned Alignment, QualType Ty,
1370                                llvm::MDNode *TBAAInfo = 0);
1371
1372  /// EmitStoreOfScalar - Store a scalar value to an address, taking
1373  /// care to appropriately convert from the memory representation to
1374  /// the LLVM value representation.
1375  void EmitStoreOfScalar(llvm::Value *Value, llvm::Value *Addr,
1376                         bool Volatile, unsigned Alignment, QualType Ty,
1377                         llvm::MDNode *TBAAInfo = 0);
1378
1379  /// EmitLoadOfLValue - Given an expression that represents a value lvalue,
1380  /// this method emits the address of the lvalue, then loads the result as an
1381  /// rvalue, returning the rvalue.
1382  RValue EmitLoadOfLValue(LValue V, QualType LVType);
1383  RValue EmitLoadOfExtVectorElementLValue(LValue V, QualType LVType);
1384  RValue EmitLoadOfBitfieldLValue(LValue LV, QualType ExprType);
1385  RValue EmitLoadOfPropertyRefLValue(LValue LV, QualType ExprType);
1386  RValue EmitLoadOfKVCRefLValue(LValue LV, QualType ExprType);
1387
1388
1389  /// EmitStoreThroughLValue - Store the specified rvalue into the specified
1390  /// lvalue, where both are guaranteed to the have the same type, and that type
1391  /// is 'Ty'.
1392  void EmitStoreThroughLValue(RValue Src, LValue Dst, QualType Ty);
1393  void EmitStoreThroughExtVectorComponentLValue(RValue Src, LValue Dst,
1394                                                QualType Ty);
1395  void EmitStoreThroughPropertyRefLValue(RValue Src, LValue Dst, QualType Ty);
1396  void EmitStoreThroughKVCRefLValue(RValue Src, LValue Dst, QualType Ty);
1397
1398  /// EmitStoreThroughLValue - Store Src into Dst with same constraints as
1399  /// EmitStoreThroughLValue.
1400  ///
1401  /// \param Result [out] - If non-null, this will be set to a Value* for the
1402  /// bit-field contents after the store, appropriate for use as the result of
1403  /// an assignment to the bit-field.
1404  void EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst, QualType Ty,
1405                                      llvm::Value **Result=0);
1406
1407  /// Emit an l-value for an assignment (simple or compound) of complex type.
1408  LValue EmitComplexAssignmentLValue(const BinaryOperator *E);
1409
1410  // Note: only availabe for agg return types
1411  LValue EmitBinaryOperatorLValue(const BinaryOperator *E);
1412  LValue EmitCompoundAssignOperatorLValue(const CompoundAssignOperator *E);
1413  // Note: only available for agg return types
1414  LValue EmitCallExprLValue(const CallExpr *E);
1415  // Note: only available for agg return types
1416  LValue EmitVAArgExprLValue(const VAArgExpr *E);
1417  LValue EmitDeclRefLValue(const DeclRefExpr *E);
1418  LValue EmitStringLiteralLValue(const StringLiteral *E);
1419  LValue EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E);
1420  LValue EmitPredefinedLValue(const PredefinedExpr *E);
1421  LValue EmitUnaryOpLValue(const UnaryOperator *E);
1422  LValue EmitArraySubscriptExpr(const ArraySubscriptExpr *E);
1423  LValue EmitExtVectorElementExpr(const ExtVectorElementExpr *E);
1424  LValue EmitMemberExpr(const MemberExpr *E);
1425  LValue EmitObjCIsaExpr(const ObjCIsaExpr *E);
1426  LValue EmitCompoundLiteralLValue(const CompoundLiteralExpr *E);
1427  LValue EmitConditionalOperatorLValue(const ConditionalOperator *E);
1428  LValue EmitCastLValue(const CastExpr *E);
1429  LValue EmitNullInitializationLValue(const CXXScalarValueInitExpr *E);
1430
1431  llvm::Value *EmitIvarOffset(const ObjCInterfaceDecl *Interface,
1432                              const ObjCIvarDecl *Ivar);
1433  LValue EmitLValueForAnonRecordField(llvm::Value* Base,
1434                                      const FieldDecl* Field,
1435                                      unsigned CVRQualifiers);
1436  LValue EmitLValueForField(llvm::Value* Base, const FieldDecl* Field,
1437                            unsigned CVRQualifiers);
1438
1439  /// EmitLValueForFieldInitialization - Like EmitLValueForField, except that
1440  /// if the Field is a reference, this will return the address of the reference
1441  /// and not the address of the value stored in the reference.
1442  LValue EmitLValueForFieldInitialization(llvm::Value* Base,
1443                                          const FieldDecl* Field,
1444                                          unsigned CVRQualifiers);
1445
1446  LValue EmitLValueForIvar(QualType ObjectTy,
1447                           llvm::Value* Base, const ObjCIvarDecl *Ivar,
1448                           unsigned CVRQualifiers);
1449
1450  LValue EmitLValueForBitfield(llvm::Value* Base, const FieldDecl* Field,
1451                                unsigned CVRQualifiers);
1452
1453  LValue EmitBlockDeclRefLValue(const BlockDeclRefExpr *E);
1454
1455  LValue EmitCXXConstructLValue(const CXXConstructExpr *E);
1456  LValue EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E);
1457  LValue EmitCXXExprWithTemporariesLValue(const CXXExprWithTemporaries *E);
1458  LValue EmitCXXTypeidLValue(const CXXTypeidExpr *E);
1459
1460  LValue EmitObjCMessageExprLValue(const ObjCMessageExpr *E);
1461  LValue EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E);
1462  LValue EmitObjCPropertyRefLValue(const ObjCPropertyRefExpr *E);
1463  LValue EmitStmtExprLValue(const StmtExpr *E);
1464  LValue EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E);
1465  LValue EmitObjCSelectorLValue(const ObjCSelectorExpr *E);
1466  void   EmitDeclRefExprDbgValue(const DeclRefExpr *E, llvm::Constant *Init);
1467  //===--------------------------------------------------------------------===//
1468  //                         Scalar Expression Emission
1469  //===--------------------------------------------------------------------===//
1470
1471  /// EmitCall - Generate a call of the given function, expecting the given
1472  /// result type, and using the given argument list which specifies both the
1473  /// LLVM arguments and the types they were derived from.
1474  ///
1475  /// \param TargetDecl - If given, the decl of the function in a direct call;
1476  /// used to set attributes on the call (noreturn, etc.).
1477  RValue EmitCall(const CGFunctionInfo &FnInfo,
1478                  llvm::Value *Callee,
1479                  ReturnValueSlot ReturnValue,
1480                  const CallArgList &Args,
1481                  const Decl *TargetDecl = 0,
1482                  llvm::Instruction **callOrInvoke = 0);
1483
1484  RValue EmitCall(QualType FnType, llvm::Value *Callee,
1485                  ReturnValueSlot ReturnValue,
1486                  CallExpr::const_arg_iterator ArgBeg,
1487                  CallExpr::const_arg_iterator ArgEnd,
1488                  const Decl *TargetDecl = 0);
1489  RValue EmitCallExpr(const CallExpr *E,
1490                      ReturnValueSlot ReturnValue = ReturnValueSlot());
1491
1492  llvm::CallSite EmitCallOrInvoke(llvm::Value *Callee,
1493                                  llvm::Value * const *ArgBegin,
1494                                  llvm::Value * const *ArgEnd,
1495                                  const llvm::Twine &Name = "");
1496
1497  llvm::Value *BuildVirtualCall(const CXXMethodDecl *MD, llvm::Value *This,
1498                                const llvm::Type *Ty);
1499  llvm::Value *BuildVirtualCall(const CXXDestructorDecl *DD, CXXDtorType Type,
1500                                llvm::Value *This, const llvm::Type *Ty);
1501
1502  RValue EmitCXXMemberCall(const CXXMethodDecl *MD,
1503                           llvm::Value *Callee,
1504                           ReturnValueSlot ReturnValue,
1505                           llvm::Value *This,
1506                           llvm::Value *VTT,
1507                           CallExpr::const_arg_iterator ArgBeg,
1508                           CallExpr::const_arg_iterator ArgEnd);
1509  RValue EmitCXXMemberCallExpr(const CXXMemberCallExpr *E,
1510                               ReturnValueSlot ReturnValue);
1511  RValue EmitCXXMemberPointerCallExpr(const CXXMemberCallExpr *E,
1512                                      ReturnValueSlot ReturnValue);
1513
1514  RValue EmitCXXOperatorMemberCallExpr(const CXXOperatorCallExpr *E,
1515                                       const CXXMethodDecl *MD,
1516                                       ReturnValueSlot ReturnValue);
1517
1518
1519  RValue EmitBuiltinExpr(const FunctionDecl *FD,
1520                         unsigned BuiltinID, const CallExpr *E);
1521
1522  RValue EmitBlockCallExpr(const CallExpr *E, ReturnValueSlot ReturnValue);
1523
1524  /// EmitTargetBuiltinExpr - Emit the given builtin call. Returns 0 if the call
1525  /// is unhandled by the current target.
1526  llvm::Value *EmitTargetBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
1527
1528  llvm::Value *EmitARMBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
1529  llvm::Value *EmitNeonCall(llvm::Function *F,
1530                            llvm::SmallVectorImpl<llvm::Value*> &O,
1531                            const char *name, bool splat = false,
1532                            unsigned shift = 0, bool rightshift = false);
1533  llvm::Value *EmitNeonSplat(llvm::Value *V, llvm::Constant *Idx,
1534                             bool widen = false);
1535  llvm::Value *EmitNeonShiftVector(llvm::Value *V, const llvm::Type *Ty,
1536                                   bool negateForRightShift);
1537
1538  llvm::Value *BuildVector(const llvm::SmallVectorImpl<llvm::Value*> &Ops);
1539  llvm::Value *EmitX86BuiltinExpr(unsigned BuiltinID, const CallExpr *E);
1540  llvm::Value *EmitPPCBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
1541
1542  llvm::Value *EmitObjCProtocolExpr(const ObjCProtocolExpr *E);
1543  llvm::Value *EmitObjCStringLiteral(const ObjCStringLiteral *E);
1544  llvm::Value *EmitObjCSelectorExpr(const ObjCSelectorExpr *E);
1545  RValue EmitObjCMessageExpr(const ObjCMessageExpr *E,
1546                             ReturnValueSlot Return = ReturnValueSlot());
1547  RValue EmitObjCPropertyGet(const ObjCPropertyRefExpr *E,
1548                             ReturnValueSlot Return = ReturnValueSlot());
1549  RValue EmitObjCSuperPropertyGet(const Expr *Exp, const Selector &S,
1550                                  ReturnValueSlot Return = ReturnValueSlot());
1551  void EmitObjCPropertySet(const ObjCPropertyRefExpr *E, RValue Src);
1552  void EmitObjCSuperPropertySet(const Expr *E, const Selector &S, RValue Src);
1553
1554
1555  /// EmitReferenceBindingToExpr - Emits a reference binding to the passed in
1556  /// expression. Will emit a temporary variable if E is not an LValue.
1557  RValue EmitReferenceBindingToExpr(const Expr* E,
1558                                    const NamedDecl *InitializedDecl);
1559
1560  //===--------------------------------------------------------------------===//
1561  //                           Expression Emission
1562  //===--------------------------------------------------------------------===//
1563
1564  // Expressions are broken into three classes: scalar, complex, aggregate.
1565
1566  /// EmitScalarExpr - Emit the computation of the specified expression of LLVM
1567  /// scalar type, returning the result.
1568  llvm::Value *EmitScalarExpr(const Expr *E , bool IgnoreResultAssign = false);
1569
1570  /// EmitScalarConversion - Emit a conversion from the specified type to the
1571  /// specified destination type, both of which are LLVM scalar types.
1572  llvm::Value *EmitScalarConversion(llvm::Value *Src, QualType SrcTy,
1573                                    QualType DstTy);
1574
1575  /// EmitComplexToScalarConversion - Emit a conversion from the specified
1576  /// complex type to the specified destination type, where the destination type
1577  /// is an LLVM scalar type.
1578  llvm::Value *EmitComplexToScalarConversion(ComplexPairTy Src, QualType SrcTy,
1579                                             QualType DstTy);
1580
1581
1582  /// EmitAggExpr - Emit the computation of the specified expression
1583  /// of aggregate type.  The result is computed into the given slot,
1584  /// which may be null to indicate that the value is not needed.
1585  void EmitAggExpr(const Expr *E, AggValueSlot AS, bool IgnoreResult = false);
1586
1587  /// EmitAggExprToLValue - Emit the computation of the specified expression of
1588  /// aggregate type into a temporary LValue.
1589  LValue EmitAggExprToLValue(const Expr *E);
1590
1591  /// EmitGCMemmoveCollectable - Emit special API for structs with object
1592  /// pointers.
1593  void EmitGCMemmoveCollectable(llvm::Value *DestPtr, llvm::Value *SrcPtr,
1594                                QualType Ty);
1595
1596  /// EmitComplexExpr - Emit the computation of the specified expression of
1597  /// complex type, returning the result.
1598  ComplexPairTy EmitComplexExpr(const Expr *E,
1599                                bool IgnoreReal = false,
1600                                bool IgnoreImag = false);
1601
1602  /// EmitComplexExprIntoAddr - Emit the computation of the specified expression
1603  /// of complex type, storing into the specified Value*.
1604  void EmitComplexExprIntoAddr(const Expr *E, llvm::Value *DestAddr,
1605                               bool DestIsVolatile);
1606
1607  /// StoreComplexToAddr - Store a complex number into the specified address.
1608  void StoreComplexToAddr(ComplexPairTy V, llvm::Value *DestAddr,
1609                          bool DestIsVolatile);
1610  /// LoadComplexFromAddr - Load a complex number from the specified address.
1611  ComplexPairTy LoadComplexFromAddr(llvm::Value *SrcAddr, bool SrcIsVolatile);
1612
1613  /// CreateStaticVarDecl - Create a zero-initialized LLVM global for
1614  /// a static local variable.
1615  llvm::GlobalVariable *CreateStaticVarDecl(const VarDecl &D,
1616                                            const char *Separator,
1617                                       llvm::GlobalValue::LinkageTypes Linkage);
1618
1619  /// AddInitializerToStaticVarDecl - Add the initializer for 'D' to the
1620  /// global variable that has already been created for it.  If the initializer
1621  /// has a different type than GV does, this may free GV and return a different
1622  /// one.  Otherwise it just returns GV.
1623  llvm::GlobalVariable *
1624  AddInitializerToStaticVarDecl(const VarDecl &D,
1625                                llvm::GlobalVariable *GV);
1626
1627
1628  /// EmitCXXGlobalVarDeclInit - Create the initializer for a C++
1629  /// variable with global storage.
1630  void EmitCXXGlobalVarDeclInit(const VarDecl &D, llvm::Constant *DeclPtr);
1631
1632  /// EmitCXXGlobalDtorRegistration - Emits a call to register the global ptr
1633  /// with the C++ runtime so that its destructor will be called at exit.
1634  void EmitCXXGlobalDtorRegistration(llvm::Constant *DtorFn,
1635                                     llvm::Constant *DeclPtr);
1636
1637  /// Emit code in this function to perform a guarded variable
1638  /// initialization.  Guarded initializations are used when it's not
1639  /// possible to prove that an initialization will be done exactly
1640  /// once, e.g. with a static local variable or a static data member
1641  /// of a class template.
1642  void EmitCXXGuardedInit(const VarDecl &D, llvm::GlobalVariable *DeclPtr);
1643
1644  /// GenerateCXXGlobalInitFunc - Generates code for initializing global
1645  /// variables.
1646  void GenerateCXXGlobalInitFunc(llvm::Function *Fn,
1647                                 llvm::Constant **Decls,
1648                                 unsigned NumDecls);
1649
1650  /// GenerateCXXGlobalDtorFunc - Generates code for destroying global
1651  /// variables.
1652  void GenerateCXXGlobalDtorFunc(llvm::Function *Fn,
1653                                 const std::vector<std::pair<llvm::WeakVH,
1654                                   llvm::Constant*> > &DtorsAndObjects);
1655
1656  void GenerateCXXGlobalVarDeclInitFunc(llvm::Function *Fn, const VarDecl *D,
1657                                        llvm::GlobalVariable *Addr);
1658
1659  void EmitCXXConstructExpr(const CXXConstructExpr *E, AggValueSlot Dest);
1660
1661  void EmitSynthesizedCXXCopyCtor(llvm::Value *Dest, llvm::Value *Src,
1662                                  const BlockDeclRefExpr *BDRE);
1663
1664  RValue EmitCXXExprWithTemporaries(const CXXExprWithTemporaries *E,
1665                                    AggValueSlot Slot =AggValueSlot::ignored());
1666
1667  void EmitCXXThrowExpr(const CXXThrowExpr *E);
1668
1669  //===--------------------------------------------------------------------===//
1670  //                             Internal Helpers
1671  //===--------------------------------------------------------------------===//
1672
1673  /// ContainsLabel - Return true if the statement contains a label in it.  If
1674  /// this statement is not executed normally, it not containing a label means
1675  /// that we can just remove the code.
1676  static bool ContainsLabel(const Stmt *S, bool IgnoreCaseStmts = false);
1677
1678  /// ConstantFoldsToSimpleInteger - If the specified expression does not fold
1679  /// to a constant, or if it does but contains a label, return 0.  If it
1680  /// constant folds to 'true' and does not contain a label, return 1, if it
1681  /// constant folds to 'false' and does not contain a label, return -1.
1682  int ConstantFoldsToSimpleInteger(const Expr *Cond);
1683
1684  /// EmitBranchOnBoolExpr - Emit a branch on a boolean condition (e.g. for an
1685  /// if statement) to the specified blocks.  Based on the condition, this might
1686  /// try to simplify the codegen of the conditional based on the branch.
1687  void EmitBranchOnBoolExpr(const Expr *Cond, llvm::BasicBlock *TrueBlock,
1688                            llvm::BasicBlock *FalseBlock);
1689
1690  /// getTrapBB - Create a basic block that will call the trap intrinsic.  We'll
1691  /// generate a branch around the created basic block as necessary.
1692  llvm::BasicBlock *getTrapBB();
1693
1694  /// EmitCallArg - Emit a single call argument.
1695  RValue EmitCallArg(const Expr *E, QualType ArgType);
1696
1697  /// EmitDelegateCallArg - We are performing a delegate call; that
1698  /// is, the current function is delegating to another one.  Produce
1699  /// a r-value suitable for passing the given parameter.
1700  RValue EmitDelegateCallArg(const VarDecl *Param);
1701
1702private:
1703  void EmitReturnOfRValue(RValue RV, QualType Ty);
1704
1705  /// ExpandTypeFromArgs - Reconstruct a structure of type \arg Ty
1706  /// from function arguments into \arg Dst. See ABIArgInfo::Expand.
1707  ///
1708  /// \param AI - The first function argument of the expansion.
1709  /// \return The argument following the last expanded function
1710  /// argument.
1711  llvm::Function::arg_iterator
1712  ExpandTypeFromArgs(QualType Ty, LValue Dst,
1713                     llvm::Function::arg_iterator AI);
1714
1715  /// ExpandTypeToArgs - Expand an RValue \arg Src, with the LLVM type for \arg
1716  /// Ty, into individual arguments on the provided vector \arg Args. See
1717  /// ABIArgInfo::Expand.
1718  void ExpandTypeToArgs(QualType Ty, RValue Src,
1719                        llvm::SmallVector<llvm::Value*, 16> &Args);
1720
1721  llvm::Value* EmitAsmInput(const AsmStmt &S,
1722                            const TargetInfo::ConstraintInfo &Info,
1723                            const Expr *InputExpr, std::string &ConstraintStr);
1724
1725  llvm::Value* EmitAsmInputLValue(const AsmStmt &S,
1726                                  const TargetInfo::ConstraintInfo &Info,
1727                                  LValue InputValue, QualType InputType,
1728                                  std::string &ConstraintStr);
1729
1730  /// EmitCallArgs - Emit call arguments for a function.
1731  /// The CallArgTypeInfo parameter is used for iterating over the known
1732  /// argument types of the function being called.
1733  template<typename T>
1734  void EmitCallArgs(CallArgList& Args, const T* CallArgTypeInfo,
1735                    CallExpr::const_arg_iterator ArgBeg,
1736                    CallExpr::const_arg_iterator ArgEnd) {
1737      CallExpr::const_arg_iterator Arg = ArgBeg;
1738
1739    // First, use the argument types that the type info knows about
1740    if (CallArgTypeInfo) {
1741      for (typename T::arg_type_iterator I = CallArgTypeInfo->arg_type_begin(),
1742           E = CallArgTypeInfo->arg_type_end(); I != E; ++I, ++Arg) {
1743        assert(Arg != ArgEnd && "Running over edge of argument list!");
1744        QualType ArgType = *I;
1745#ifndef NDEBUG
1746        QualType ActualArgType = Arg->getType();
1747        if (ArgType->isPointerType() && ActualArgType->isPointerType()) {
1748          QualType ActualBaseType =
1749            ActualArgType->getAs<PointerType>()->getPointeeType();
1750          QualType ArgBaseType =
1751            ArgType->getAs<PointerType>()->getPointeeType();
1752          if (ArgBaseType->isVariableArrayType()) {
1753            if (const VariableArrayType *VAT =
1754                getContext().getAsVariableArrayType(ActualBaseType)) {
1755              if (!VAT->getSizeExpr())
1756                ActualArgType = ArgType;
1757            }
1758          }
1759        }
1760        assert(getContext().getCanonicalType(ArgType.getNonReferenceType()).
1761               getTypePtr() ==
1762               getContext().getCanonicalType(ActualArgType).getTypePtr() &&
1763               "type mismatch in call argument!");
1764#endif
1765        Args.push_back(std::make_pair(EmitCallArg(*Arg, ArgType),
1766                                      ArgType));
1767      }
1768
1769      // Either we've emitted all the call args, or we have a call to a
1770      // variadic function.
1771      assert((Arg == ArgEnd || CallArgTypeInfo->isVariadic()) &&
1772             "Extra arguments in non-variadic function!");
1773
1774    }
1775
1776    // If we still have any arguments, emit them using the type of the argument.
1777    for (; Arg != ArgEnd; ++Arg) {
1778      QualType ArgType = Arg->getType();
1779      Args.push_back(std::make_pair(EmitCallArg(*Arg, ArgType),
1780                                    ArgType));
1781    }
1782  }
1783
1784  const TargetCodeGenInfo &getTargetHooks() const {
1785    return CGM.getTargetCodeGenInfo();
1786  }
1787
1788  void EmitDeclMetadata();
1789};
1790
1791/// CGBlockInfo - Information to generate a block literal.
1792class CGBlockInfo {
1793public:
1794  /// Name - The name of the block, kindof.
1795  const char *Name;
1796
1797  /// DeclRefs - Variables from parent scopes that have been
1798  /// imported into this block.
1799  llvm::SmallVector<const BlockDeclRefExpr *, 8> DeclRefs;
1800
1801  /// InnerBlocks - This block and the blocks it encloses.
1802  llvm::SmallPtrSet<const DeclContext *, 4> InnerBlocks;
1803
1804  /// CXXThisRef - Non-null if 'this' was required somewhere, in
1805  /// which case this is that expression.
1806  const CXXThisExpr *CXXThisRef;
1807
1808  /// NeedsObjCSelf - True if something in this block has an implicit
1809  /// reference to 'self'.
1810  bool NeedsObjCSelf : 1;
1811
1812  /// HasCXXObject - True if block has imported c++ object requiring copy
1813  /// construction in copy helper and destruction in copy dispose helpers.
1814  bool HasCXXObject : 1;
1815
1816  /// These are initialized by GenerateBlockFunction.
1817  bool BlockHasCopyDispose : 1;
1818  CharUnits BlockSize;
1819  CharUnits BlockAlign;
1820  llvm::SmallVector<const Expr*, 8> BlockLayout;
1821
1822  CGBlockInfo(const char *Name);
1823};
1824
1825}  // end namespace CodeGen
1826}  // end namespace clang
1827
1828#endif
1829