clang  9.0.0svn
CGExprConstant.cpp
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1 //===--- CGExprConstant.cpp - Emit LLVM Code from Constant Expressions ----===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This contains code to emit Constant Expr nodes as LLVM code.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "CodeGenFunction.h"
14 #include "CGCXXABI.h"
15 #include "CGObjCRuntime.h"
16 #include "CGRecordLayout.h"
17 #include "CodeGenModule.h"
18 #include "ConstantEmitter.h"
19 #include "TargetInfo.h"
20 #include "clang/AST/APValue.h"
21 #include "clang/AST/ASTContext.h"
22 #include "clang/AST/RecordLayout.h"
23 #include "clang/AST/StmtVisitor.h"
24 #include "clang/Basic/Builtins.h"
25 #include "llvm/IR/Constants.h"
26 #include "llvm/IR/DataLayout.h"
27 #include "llvm/IR/Function.h"
28 #include "llvm/IR/GlobalVariable.h"
29 using namespace clang;
30 using namespace CodeGen;
31 
32 //===----------------------------------------------------------------------===//
33 // ConstStructBuilder
34 //===----------------------------------------------------------------------===//
35 
36 namespace {
37 class ConstExprEmitter;
38 class ConstStructBuilder {
39  CodeGenModule &CGM;
40  ConstantEmitter &Emitter;
41 
42  bool Packed;
43  CharUnits NextFieldOffsetInChars;
44  CharUnits LLVMStructAlignment;
46 public:
47  static llvm::Constant *BuildStruct(ConstantEmitter &Emitter,
48  ConstExprEmitter *ExprEmitter,
49  llvm::Constant *Base,
50  InitListExpr *Updater,
51  QualType ValTy);
52  static llvm::Constant *BuildStruct(ConstantEmitter &Emitter,
53  InitListExpr *ILE, QualType StructTy);
54  static llvm::Constant *BuildStruct(ConstantEmitter &Emitter,
55  const APValue &Value, QualType ValTy);
56 
57 private:
58  ConstStructBuilder(ConstantEmitter &emitter)
59  : CGM(emitter.CGM), Emitter(emitter), Packed(false),
60  NextFieldOffsetInChars(CharUnits::Zero()),
61  LLVMStructAlignment(CharUnits::One()) { }
62 
63  void AppendField(const FieldDecl *Field, uint64_t FieldOffset,
64  llvm::Constant *InitExpr);
65 
66  void AppendBytes(CharUnits FieldOffsetInChars, llvm::Constant *InitCst);
67 
68  void AppendBitField(const FieldDecl *Field, uint64_t FieldOffset,
69  llvm::ConstantInt *InitExpr);
70 
71  void AppendPadding(CharUnits PadSize);
72 
73  void AppendTailPadding(CharUnits RecordSize);
74 
75  void ConvertStructToPacked();
76 
77  bool Build(InitListExpr *ILE);
78  bool Build(ConstExprEmitter *Emitter, llvm::Constant *Base,
79  InitListExpr *Updater);
80  bool Build(const APValue &Val, const RecordDecl *RD, bool IsPrimaryBase,
81  const CXXRecordDecl *VTableClass, CharUnits BaseOffset);
82  llvm::Constant *Finalize(QualType Ty);
83 
84  CharUnits getAlignment(const llvm::Constant *C) const {
85  if (Packed) return CharUnits::One();
87  CGM.getDataLayout().getABITypeAlignment(C->getType()));
88  }
89 
90  CharUnits getSizeInChars(const llvm::Constant *C) const {
92  CGM.getDataLayout().getTypeAllocSize(C->getType()));
93  }
94 };
95 
96 void ConstStructBuilder::
97 AppendField(const FieldDecl *Field, uint64_t FieldOffset,
98  llvm::Constant *InitCst) {
99  const ASTContext &Context = CGM.getContext();
100 
101  CharUnits FieldOffsetInChars = Context.toCharUnitsFromBits(FieldOffset);
102 
103  AppendBytes(FieldOffsetInChars, InitCst);
104 }
105 
106 void ConstStructBuilder::
107 AppendBytes(CharUnits FieldOffsetInChars, llvm::Constant *InitCst) {
108 
109  assert(NextFieldOffsetInChars <= FieldOffsetInChars
110  && "Field offset mismatch!");
111 
112  CharUnits FieldAlignment = getAlignment(InitCst);
113 
114  // Round up the field offset to the alignment of the field type.
115  CharUnits AlignedNextFieldOffsetInChars =
116  NextFieldOffsetInChars.alignTo(FieldAlignment);
117 
118  if (AlignedNextFieldOffsetInChars < FieldOffsetInChars) {
119  // We need to append padding.
120  AppendPadding(FieldOffsetInChars - NextFieldOffsetInChars);
121 
122  assert(NextFieldOffsetInChars == FieldOffsetInChars &&
123  "Did not add enough padding!");
124 
125  AlignedNextFieldOffsetInChars =
126  NextFieldOffsetInChars.alignTo(FieldAlignment);
127  }
128 
129  if (AlignedNextFieldOffsetInChars > FieldOffsetInChars) {
130  assert(!Packed && "Alignment is wrong even with a packed struct!");
131 
132  // Convert the struct to a packed struct.
133  ConvertStructToPacked();
134 
135  // After we pack the struct, we may need to insert padding.
136  if (NextFieldOffsetInChars < FieldOffsetInChars) {
137  // We need to append padding.
138  AppendPadding(FieldOffsetInChars - NextFieldOffsetInChars);
139 
140  assert(NextFieldOffsetInChars == FieldOffsetInChars &&
141  "Did not add enough padding!");
142  }
143  AlignedNextFieldOffsetInChars = NextFieldOffsetInChars;
144  }
145 
146  // Add the field.
147  Elements.push_back(InitCst);
148  NextFieldOffsetInChars = AlignedNextFieldOffsetInChars +
149  getSizeInChars(InitCst);
150 
151  if (Packed)
152  assert(LLVMStructAlignment == CharUnits::One() &&
153  "Packed struct not byte-aligned!");
154  else
155  LLVMStructAlignment = std::max(LLVMStructAlignment, FieldAlignment);
156 }
157 
158 void ConstStructBuilder::AppendBitField(const FieldDecl *Field,
159  uint64_t FieldOffset,
160  llvm::ConstantInt *CI) {
161  const ASTContext &Context = CGM.getContext();
162  const uint64_t CharWidth = Context.getCharWidth();
163  uint64_t NextFieldOffsetInBits = Context.toBits(NextFieldOffsetInChars);
164  if (FieldOffset > NextFieldOffsetInBits) {
165  // We need to add padding.
166  CharUnits PadSize = Context.toCharUnitsFromBits(
167  llvm::alignTo(FieldOffset - NextFieldOffsetInBits,
168  Context.getTargetInfo().getCharAlign()));
169 
170  AppendPadding(PadSize);
171  }
172 
173  uint64_t FieldSize = Field->getBitWidthValue(Context);
174 
175  llvm::APInt FieldValue = CI->getValue();
176 
177  // Promote the size of FieldValue if necessary
178  // FIXME: This should never occur, but currently it can because initializer
179  // constants are cast to bool, and because clang is not enforcing bitfield
180  // width limits.
181  if (FieldSize > FieldValue.getBitWidth())
182  FieldValue = FieldValue.zext(FieldSize);
183 
184  // Truncate the size of FieldValue to the bit field size.
185  if (FieldSize < FieldValue.getBitWidth())
186  FieldValue = FieldValue.trunc(FieldSize);
187 
188  NextFieldOffsetInBits = Context.toBits(NextFieldOffsetInChars);
189  if (FieldOffset < NextFieldOffsetInBits) {
190  // Either part of the field or the entire field can go into the previous
191  // byte.
192  assert(!Elements.empty() && "Elements can't be empty!");
193 
194  unsigned BitsInPreviousByte = NextFieldOffsetInBits - FieldOffset;
195 
196  bool FitsCompletelyInPreviousByte =
197  BitsInPreviousByte >= FieldValue.getBitWidth();
198 
199  llvm::APInt Tmp = FieldValue;
200 
201  if (!FitsCompletelyInPreviousByte) {
202  unsigned NewFieldWidth = FieldSize - BitsInPreviousByte;
203 
204  if (CGM.getDataLayout().isBigEndian()) {
205  Tmp.lshrInPlace(NewFieldWidth);
206  Tmp = Tmp.trunc(BitsInPreviousByte);
207 
208  // We want the remaining high bits.
209  FieldValue = FieldValue.trunc(NewFieldWidth);
210  } else {
211  Tmp = Tmp.trunc(BitsInPreviousByte);
212 
213  // We want the remaining low bits.
214  FieldValue.lshrInPlace(BitsInPreviousByte);
215  FieldValue = FieldValue.trunc(NewFieldWidth);
216  }
217  }
218 
219  Tmp = Tmp.zext(CharWidth);
220  if (CGM.getDataLayout().isBigEndian()) {
221  if (FitsCompletelyInPreviousByte)
222  Tmp = Tmp.shl(BitsInPreviousByte - FieldValue.getBitWidth());
223  } else {
224  Tmp = Tmp.shl(CharWidth - BitsInPreviousByte);
225  }
226 
227  // 'or' in the bits that go into the previous byte.
228  llvm::Value *LastElt = Elements.back();
229  if (llvm::ConstantInt *Val = dyn_cast<llvm::ConstantInt>(LastElt))
230  Tmp |= Val->getValue();
231  else {
232  assert(isa<llvm::UndefValue>(LastElt));
233  // If there is an undef field that we're adding to, it can either be a
234  // scalar undef (in which case, we just replace it with our field) or it
235  // is an array. If it is an array, we have to pull one byte off the
236  // array so that the other undef bytes stay around.
237  if (!isa<llvm::IntegerType>(LastElt->getType())) {
238  // The undef padding will be a multibyte array, create a new smaller
239  // padding and then an hole for our i8 to get plopped into.
240  assert(isa<llvm::ArrayType>(LastElt->getType()) &&
241  "Expected array padding of undefs");
242  llvm::ArrayType *AT = cast<llvm::ArrayType>(LastElt->getType());
243  assert(AT->getElementType()->isIntegerTy(CharWidth) &&
244  AT->getNumElements() != 0 &&
245  "Expected non-empty array padding of undefs");
246 
247  // Remove the padding array.
248  NextFieldOffsetInChars -= CharUnits::fromQuantity(AT->getNumElements());
249  Elements.pop_back();
250 
251  // Add the padding back in two chunks.
252  AppendPadding(CharUnits::fromQuantity(AT->getNumElements()-1));
253  AppendPadding(CharUnits::One());
254  assert(isa<llvm::UndefValue>(Elements.back()) &&
255  Elements.back()->getType()->isIntegerTy(CharWidth) &&
256  "Padding addition didn't work right");
257  }
258  }
259 
260  Elements.back() = llvm::ConstantInt::get(CGM.getLLVMContext(), Tmp);
261 
262  if (FitsCompletelyInPreviousByte)
263  return;
264  }
265 
266  while (FieldValue.getBitWidth() > CharWidth) {
267  llvm::APInt Tmp;
268 
269  if (CGM.getDataLayout().isBigEndian()) {
270  // We want the high bits.
271  Tmp =
272  FieldValue.lshr(FieldValue.getBitWidth() - CharWidth).trunc(CharWidth);
273  } else {
274  // We want the low bits.
275  Tmp = FieldValue.trunc(CharWidth);
276 
277  FieldValue.lshrInPlace(CharWidth);
278  }
279 
280  Elements.push_back(llvm::ConstantInt::get(CGM.getLLVMContext(), Tmp));
281  ++NextFieldOffsetInChars;
282 
283  FieldValue = FieldValue.trunc(FieldValue.getBitWidth() - CharWidth);
284  }
285 
286  assert(FieldValue.getBitWidth() > 0 &&
287  "Should have at least one bit left!");
288  assert(FieldValue.getBitWidth() <= CharWidth &&
289  "Should not have more than a byte left!");
290 
291  if (FieldValue.getBitWidth() < CharWidth) {
292  if (CGM.getDataLayout().isBigEndian()) {
293  unsigned BitWidth = FieldValue.getBitWidth();
294 
295  FieldValue = FieldValue.zext(CharWidth) << (CharWidth - BitWidth);
296  } else
297  FieldValue = FieldValue.zext(CharWidth);
298  }
299 
300  // Append the last element.
301  Elements.push_back(llvm::ConstantInt::get(CGM.getLLVMContext(),
302  FieldValue));
303  ++NextFieldOffsetInChars;
304 }
305 
306 void ConstStructBuilder::AppendPadding(CharUnits PadSize) {
307  if (PadSize.isZero())
308  return;
309 
310  llvm::Type *Ty = CGM.Int8Ty;
311  if (PadSize > CharUnits::One())
312  Ty = llvm::ArrayType::get(Ty, PadSize.getQuantity());
313 
314  llvm::Constant *C = llvm::UndefValue::get(Ty);
315  Elements.push_back(C);
316  assert(getAlignment(C) == CharUnits::One() &&
317  "Padding must have 1 byte alignment!");
318 
319  NextFieldOffsetInChars += getSizeInChars(C);
320 }
321 
322 void ConstStructBuilder::AppendTailPadding(CharUnits RecordSize) {
323  assert(NextFieldOffsetInChars <= RecordSize &&
324  "Size mismatch!");
325 
326  AppendPadding(RecordSize - NextFieldOffsetInChars);
327 }
328 
329 void ConstStructBuilder::ConvertStructToPacked() {
330  SmallVector<llvm::Constant *, 16> PackedElements;
331  CharUnits ElementOffsetInChars = CharUnits::Zero();
332 
333  for (unsigned i = 0, e = Elements.size(); i != e; ++i) {
334  llvm::Constant *C = Elements[i];
335 
336  CharUnits ElementAlign = CharUnits::fromQuantity(
337  CGM.getDataLayout().getABITypeAlignment(C->getType()));
338  CharUnits AlignedElementOffsetInChars =
339  ElementOffsetInChars.alignTo(ElementAlign);
340 
341  if (AlignedElementOffsetInChars > ElementOffsetInChars) {
342  // We need some padding.
343  CharUnits NumChars =
344  AlignedElementOffsetInChars - ElementOffsetInChars;
345 
346  llvm::Type *Ty = CGM.Int8Ty;
347  if (NumChars > CharUnits::One())
348  Ty = llvm::ArrayType::get(Ty, NumChars.getQuantity());
349 
350  llvm::Constant *Padding = llvm::UndefValue::get(Ty);
351  PackedElements.push_back(Padding);
352  ElementOffsetInChars += getSizeInChars(Padding);
353  }
354 
355  PackedElements.push_back(C);
356  ElementOffsetInChars += getSizeInChars(C);
357  }
358 
359  assert(ElementOffsetInChars == NextFieldOffsetInChars &&
360  "Packing the struct changed its size!");
361 
362  Elements.swap(PackedElements);
363  LLVMStructAlignment = CharUnits::One();
364  Packed = true;
365 }
366 
367 bool ConstStructBuilder::Build(InitListExpr *ILE) {
368  RecordDecl *RD = ILE->getType()->getAs<RecordType>()->getDecl();
369  const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
370 
371  unsigned FieldNo = 0;
372  unsigned ElementNo = 0;
373 
374  // Bail out if we have base classes. We could support these, but they only
375  // arise in C++1z where we will have already constant folded most interesting
376  // cases. FIXME: There are still a few more cases we can handle this way.
377  if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD))
378  if (CXXRD->getNumBases())
379  return false;
380 
381  for (RecordDecl::field_iterator Field = RD->field_begin(),
382  FieldEnd = RD->field_end(); Field != FieldEnd; ++Field, ++FieldNo) {
383  // If this is a union, skip all the fields that aren't being initialized.
384  if (RD->isUnion() && ILE->getInitializedFieldInUnion() != *Field)
385  continue;
386 
387  // Don't emit anonymous bitfields, they just affect layout.
388  if (Field->isUnnamedBitfield())
389  continue;
390 
391  // Get the initializer. A struct can include fields without initializers,
392  // we just use explicit null values for them.
393  llvm::Constant *EltInit;
394  if (ElementNo < ILE->getNumInits())
395  EltInit = Emitter.tryEmitPrivateForMemory(ILE->getInit(ElementNo++),
396  Field->getType());
397  else
398  EltInit = Emitter.emitNullForMemory(Field->getType());
399 
400  if (!EltInit)
401  return false;
402 
403  if (!Field->isBitField()) {
404  // Handle non-bitfield members.
405  AppendField(*Field, Layout.getFieldOffset(FieldNo), EltInit);
406  } else {
407  // Otherwise we have a bitfield.
408  if (auto *CI = dyn_cast<llvm::ConstantInt>(EltInit)) {
409  AppendBitField(*Field, Layout.getFieldOffset(FieldNo), CI);
410  } else {
411  // We are trying to initialize a bitfield with a non-trivial constant,
412  // this must require run-time code.
413  return false;
414  }
415  }
416  }
417 
418  return true;
419 }
420 
421 namespace {
422 struct BaseInfo {
423  BaseInfo(const CXXRecordDecl *Decl, CharUnits Offset, unsigned Index)
424  : Decl(Decl), Offset(Offset), Index(Index) {
425  }
426 
427  const CXXRecordDecl *Decl;
429  unsigned Index;
430 
431  bool operator<(const BaseInfo &O) const { return Offset < O.Offset; }
432 };
433 }
434 
435 bool ConstStructBuilder::Build(const APValue &Val, const RecordDecl *RD,
436  bool IsPrimaryBase,
437  const CXXRecordDecl *VTableClass,
438  CharUnits Offset) {
439  const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
440 
441  if (const CXXRecordDecl *CD = dyn_cast<CXXRecordDecl>(RD)) {
442  // Add a vtable pointer, if we need one and it hasn't already been added.
443  if (CD->isDynamicClass() && !IsPrimaryBase) {
444  llvm::Constant *VTableAddressPoint =
446  BaseSubobject(CD, Offset), VTableClass);
447  AppendBytes(Offset, VTableAddressPoint);
448  }
449 
450  // Accumulate and sort bases, in order to visit them in address order, which
451  // may not be the same as declaration order.
453  Bases.reserve(CD->getNumBases());
454  unsigned BaseNo = 0;
455  for (CXXRecordDecl::base_class_const_iterator Base = CD->bases_begin(),
456  BaseEnd = CD->bases_end(); Base != BaseEnd; ++Base, ++BaseNo) {
457  assert(!Base->isVirtual() && "should not have virtual bases here");
458  const CXXRecordDecl *BD = Base->getType()->getAsCXXRecordDecl();
459  CharUnits BaseOffset = Layout.getBaseClassOffset(BD);
460  Bases.push_back(BaseInfo(BD, BaseOffset, BaseNo));
461  }
462  llvm::stable_sort(Bases);
463 
464  for (unsigned I = 0, N = Bases.size(); I != N; ++I) {
465  BaseInfo &Base = Bases[I];
466 
467  bool IsPrimaryBase = Layout.getPrimaryBase() == Base.Decl;
468  Build(Val.getStructBase(Base.Index), Base.Decl, IsPrimaryBase,
469  VTableClass, Offset + Base.Offset);
470  }
471  }
472 
473  unsigned FieldNo = 0;
474  uint64_t OffsetBits = CGM.getContext().toBits(Offset);
475 
476  for (RecordDecl::field_iterator Field = RD->field_begin(),
477  FieldEnd = RD->field_end(); Field != FieldEnd; ++Field, ++FieldNo) {
478  // If this is a union, skip all the fields that aren't being initialized.
479  if (RD->isUnion() && !declaresSameEntity(Val.getUnionField(), *Field))
480  continue;
481 
482  // Don't emit anonymous bitfields, they just affect layout.
483  if (Field->isUnnamedBitfield())
484  continue;
485 
486  // Emit the value of the initializer.
487  const APValue &FieldValue =
488  RD->isUnion() ? Val.getUnionValue() : Val.getStructField(FieldNo);
489  llvm::Constant *EltInit =
490  Emitter.tryEmitPrivateForMemory(FieldValue, Field->getType());
491  if (!EltInit)
492  return false;
493 
494  if (!Field->isBitField()) {
495  // Handle non-bitfield members.
496  AppendField(*Field, Layout.getFieldOffset(FieldNo) + OffsetBits, EltInit);
497  } else {
498  // Otherwise we have a bitfield.
499  AppendBitField(*Field, Layout.getFieldOffset(FieldNo) + OffsetBits,
500  cast<llvm::ConstantInt>(EltInit));
501  }
502  }
503 
504  return true;
505 }
506 
507 llvm::Constant *ConstStructBuilder::Finalize(QualType Ty) {
508  RecordDecl *RD = Ty->getAs<RecordType>()->getDecl();
509  const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
510 
511  CharUnits LayoutSizeInChars = Layout.getSize();
512 
513  if (NextFieldOffsetInChars > LayoutSizeInChars) {
514  // If the struct is bigger than the size of the record type,
515  // we must have a flexible array member at the end.
516  assert(RD->hasFlexibleArrayMember() &&
517  "Must have flexible array member if struct is bigger than type!");
518 
519  // No tail padding is necessary.
520  } else {
521  // Append tail padding if necessary.
522  CharUnits LLVMSizeInChars =
523  NextFieldOffsetInChars.alignTo(LLVMStructAlignment);
524 
525  if (LLVMSizeInChars != LayoutSizeInChars)
526  AppendTailPadding(LayoutSizeInChars);
527 
528  LLVMSizeInChars = NextFieldOffsetInChars.alignTo(LLVMStructAlignment);
529 
530  // Check if we need to convert the struct to a packed struct.
531  if (NextFieldOffsetInChars <= LayoutSizeInChars &&
532  LLVMSizeInChars > LayoutSizeInChars) {
533  assert(!Packed && "Size mismatch!");
534 
535  ConvertStructToPacked();
536  assert(NextFieldOffsetInChars <= LayoutSizeInChars &&
537  "Converting to packed did not help!");
538  }
539 
540  LLVMSizeInChars = NextFieldOffsetInChars.alignTo(LLVMStructAlignment);
541 
542  assert(LayoutSizeInChars == LLVMSizeInChars &&
543  "Tail padding mismatch!");
544  }
545 
546  // Pick the type to use. If the type is layout identical to the ConvertType
547  // type then use it, otherwise use whatever the builder produced for us.
548  llvm::StructType *STy =
549  llvm::ConstantStruct::getTypeForElements(CGM.getLLVMContext(),
550  Elements, Packed);
551  llvm::Type *ValTy = CGM.getTypes().ConvertType(Ty);
552  if (llvm::StructType *ValSTy = dyn_cast<llvm::StructType>(ValTy)) {
553  if (ValSTy->isLayoutIdentical(STy))
554  STy = ValSTy;
555  }
556 
557  llvm::Constant *Result = llvm::ConstantStruct::get(STy, Elements);
558 
559  assert(NextFieldOffsetInChars.alignTo(getAlignment(Result)) ==
560  getSizeInChars(Result) &&
561  "Size mismatch!");
562 
563  return Result;
564 }
565 
566 llvm::Constant *ConstStructBuilder::BuildStruct(ConstantEmitter &Emitter,
567  ConstExprEmitter *ExprEmitter,
568  llvm::Constant *Base,
569  InitListExpr *Updater,
570  QualType ValTy) {
571  ConstStructBuilder Builder(Emitter);
572  if (!Builder.Build(ExprEmitter, Base, Updater))
573  return nullptr;
574  return Builder.Finalize(ValTy);
575 }
576 
577 llvm::Constant *ConstStructBuilder::BuildStruct(ConstantEmitter &Emitter,
578  InitListExpr *ILE,
579  QualType ValTy) {
580  ConstStructBuilder Builder(Emitter);
581 
582  if (!Builder.Build(ILE))
583  return nullptr;
584 
585  return Builder.Finalize(ValTy);
586 }
587 
588 llvm::Constant *ConstStructBuilder::BuildStruct(ConstantEmitter &Emitter,
589  const APValue &Val,
590  QualType ValTy) {
591  ConstStructBuilder Builder(Emitter);
592 
593  const RecordDecl *RD = ValTy->castAs<RecordType>()->getDecl();
594  const CXXRecordDecl *CD = dyn_cast<CXXRecordDecl>(RD);
595  if (!Builder.Build(Val, RD, false, CD, CharUnits::Zero()))
596  return nullptr;
597 
598  return Builder.Finalize(ValTy);
599 }
600 
601 
602 //===----------------------------------------------------------------------===//
603 // ConstExprEmitter
604 //===----------------------------------------------------------------------===//
605 
606 static ConstantAddress tryEmitGlobalCompoundLiteral(CodeGenModule &CGM,
607  CodeGenFunction *CGF,
608  const CompoundLiteralExpr *E) {
609  CharUnits Align = CGM.getContext().getTypeAlignInChars(E->getType());
610  if (llvm::GlobalVariable *Addr =
612  return ConstantAddress(Addr, Align);
613 
614  LangAS addressSpace = E->getType().getAddressSpace();
615 
616  ConstantEmitter emitter(CGM, CGF);
617  llvm::Constant *C = emitter.tryEmitForInitializer(E->getInitializer(),
618  addressSpace, E->getType());
619  if (!C) {
620  assert(!E->isFileScope() &&
621  "file-scope compound literal did not have constant initializer!");
622  return ConstantAddress::invalid();
623  }
624 
625  auto GV = new llvm::GlobalVariable(CGM.getModule(), C->getType(),
626  CGM.isTypeConstant(E->getType(), true),
628  C, ".compoundliteral", nullptr,
629  llvm::GlobalVariable::NotThreadLocal,
630  CGM.getContext().getTargetAddressSpace(addressSpace));
631  emitter.finalize(GV);
632  GV->setAlignment(Align.getQuantity());
634  return ConstantAddress(GV, Align);
635 }
636 
637 static llvm::Constant *
638 EmitArrayConstant(CodeGenModule &CGM, const ConstantArrayType *DestType,
639  llvm::Type *CommonElementType, unsigned ArrayBound,
641  llvm::Constant *Filler) {
642  // Figure out how long the initial prefix of non-zero elements is.
643  unsigned NonzeroLength = ArrayBound;
644  if (Elements.size() < NonzeroLength && Filler->isNullValue())
645  NonzeroLength = Elements.size();
646  if (NonzeroLength == Elements.size()) {
647  while (NonzeroLength > 0 && Elements[NonzeroLength - 1]->isNullValue())
648  --NonzeroLength;
649  }
650 
651  if (NonzeroLength == 0) {
652  return llvm::ConstantAggregateZero::get(
653  CGM.getTypes().ConvertType(QualType(DestType, 0)));
654  }
655 
656  // Add a zeroinitializer array filler if we have lots of trailing zeroes.
657  unsigned TrailingZeroes = ArrayBound - NonzeroLength;
658  if (TrailingZeroes >= 8) {
659  assert(Elements.size() >= NonzeroLength &&
660  "missing initializer for non-zero element");
661 
662  // If all the elements had the same type up to the trailing zeroes, emit a
663  // struct of two arrays (the nonzero data and the zeroinitializer).
664  if (CommonElementType && NonzeroLength >= 8) {
665  llvm::Constant *Initial = llvm::ConstantArray::get(
666  llvm::ArrayType::get(CommonElementType, NonzeroLength),
667  makeArrayRef(Elements).take_front(NonzeroLength));
668  Elements.resize(2);
669  Elements[0] = Initial;
670  } else {
671  Elements.resize(NonzeroLength + 1);
672  }
673 
674  auto *FillerType =
675  CommonElementType
676  ? CommonElementType
677  : CGM.getTypes().ConvertType(DestType->getElementType());
678  FillerType = llvm::ArrayType::get(FillerType, TrailingZeroes);
679  Elements.back() = llvm::ConstantAggregateZero::get(FillerType);
680  CommonElementType = nullptr;
681  } else if (Elements.size() != ArrayBound) {
682  // Otherwise pad to the right size with the filler if necessary.
683  Elements.resize(ArrayBound, Filler);
684  if (Filler->getType() != CommonElementType)
685  CommonElementType = nullptr;
686  }
687 
688  // If all elements have the same type, just emit an array constant.
689  if (CommonElementType)
690  return llvm::ConstantArray::get(
691  llvm::ArrayType::get(CommonElementType, ArrayBound), Elements);
692 
693  // We have mixed types. Use a packed struct.
695  Types.reserve(Elements.size());
696  for (llvm::Constant *Elt : Elements)
697  Types.push_back(Elt->getType());
698  llvm::StructType *SType =
699  llvm::StructType::get(CGM.getLLVMContext(), Types, true);
700  return llvm::ConstantStruct::get(SType, Elements);
701 }
702 
703 // This class only needs to handle arrays, structs and unions. Outside C++11
704 // mode, we don't currently constant fold those types. All other types are
705 // handled by constant folding.
706 //
707 // Constant folding is currently missing support for a few features supported
708 // here: CK_ToUnion, CK_ReinterpretMemberPointer, and DesignatedInitUpdateExpr.
709 class ConstExprEmitter :
710  public StmtVisitor<ConstExprEmitter, llvm::Constant*, QualType> {
711  CodeGenModule &CGM;
712  ConstantEmitter &Emitter;
713  llvm::LLVMContext &VMContext;
714 public:
715  ConstExprEmitter(ConstantEmitter &emitter)
716  : CGM(emitter.CGM), Emitter(emitter), VMContext(CGM.getLLVMContext()) {
717  }
718 
719  //===--------------------------------------------------------------------===//
720  // Visitor Methods
721  //===--------------------------------------------------------------------===//
722 
723  llvm::Constant *VisitStmt(Stmt *S, QualType T) {
724  return nullptr;
725  }
726 
727  llvm::Constant *VisitConstantExpr(ConstantExpr *CE, QualType T) {
728  return Visit(CE->getSubExpr(), T);
729  }
730 
731  llvm::Constant *VisitParenExpr(ParenExpr *PE, QualType T) {
732  return Visit(PE->getSubExpr(), T);
733  }
734 
735  llvm::Constant *
736  VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *PE,
737  QualType T) {
738  return Visit(PE->getReplacement(), T);
739  }
740 
741  llvm::Constant *VisitGenericSelectionExpr(GenericSelectionExpr *GE,
742  QualType T) {
743  return Visit(GE->getResultExpr(), T);
744  }
745 
746  llvm::Constant *VisitChooseExpr(ChooseExpr *CE, QualType T) {
747  return Visit(CE->getChosenSubExpr(), T);
748  }
749 
750  llvm::Constant *VisitCompoundLiteralExpr(CompoundLiteralExpr *E, QualType T) {
751  return Visit(E->getInitializer(), T);
752  }
753 
754  llvm::Constant *VisitCastExpr(CastExpr *E, QualType destType) {
755  if (const auto *ECE = dyn_cast<ExplicitCastExpr>(E))
756  CGM.EmitExplicitCastExprType(ECE, Emitter.CGF);
757  Expr *subExpr = E->getSubExpr();
758 
759  switch (E->getCastKind()) {
760  case CK_ToUnion: {
761  // GCC cast to union extension
762  assert(E->getType()->isUnionType() &&
763  "Destination type is not union type!");
764 
765  auto field = E->getTargetUnionField();
766 
767  auto C = Emitter.tryEmitPrivateForMemory(subExpr, field->getType());
768  if (!C) return nullptr;
769 
770  auto destTy = ConvertType(destType);
771  if (C->getType() == destTy) return C;
772 
773  // Build a struct with the union sub-element as the first member,
774  // and padded to the appropriate size.
777  Elts.push_back(C);
778  Types.push_back(C->getType());
779  unsigned CurSize = CGM.getDataLayout().getTypeAllocSize(C->getType());
780  unsigned TotalSize = CGM.getDataLayout().getTypeAllocSize(destTy);
781 
782  assert(CurSize <= TotalSize && "Union size mismatch!");
783  if (unsigned NumPadBytes = TotalSize - CurSize) {
784  llvm::Type *Ty = CGM.Int8Ty;
785  if (NumPadBytes > 1)
786  Ty = llvm::ArrayType::get(Ty, NumPadBytes);
787 
788  Elts.push_back(llvm::UndefValue::get(Ty));
789  Types.push_back(Ty);
790  }
791 
792  llvm::StructType *STy = llvm::StructType::get(VMContext, Types, false);
793  return llvm::ConstantStruct::get(STy, Elts);
794  }
795 
796  case CK_AddressSpaceConversion: {
797  auto C = Emitter.tryEmitPrivate(subExpr, subExpr->getType());
798  if (!C) return nullptr;
799  LangAS destAS = E->getType()->getPointeeType().getAddressSpace();
800  LangAS srcAS = subExpr->getType()->getPointeeType().getAddressSpace();
801  llvm::Type *destTy = ConvertType(E->getType());
802  return CGM.getTargetCodeGenInfo().performAddrSpaceCast(CGM, C, srcAS,
803  destAS, destTy);
804  }
805 
806  case CK_LValueToRValue:
807  case CK_AtomicToNonAtomic:
808  case CK_NonAtomicToAtomic:
809  case CK_NoOp:
810  case CK_ConstructorConversion:
811  return Visit(subExpr, destType);
812 
813  case CK_IntToOCLSampler:
814  llvm_unreachable("global sampler variables are not generated");
815 
816  case CK_Dependent: llvm_unreachable("saw dependent cast!");
817 
818  case CK_BuiltinFnToFnPtr:
819  llvm_unreachable("builtin functions are handled elsewhere");
820 
821  case CK_ReinterpretMemberPointer:
822  case CK_DerivedToBaseMemberPointer:
823  case CK_BaseToDerivedMemberPointer: {
824  auto C = Emitter.tryEmitPrivate(subExpr, subExpr->getType());
825  if (!C) return nullptr;
826  return CGM.getCXXABI().EmitMemberPointerConversion(E, C);
827  }
828 
829  // These will never be supported.
830  case CK_ObjCObjectLValueCast:
831  case CK_ARCProduceObject:
832  case CK_ARCConsumeObject:
833  case CK_ARCReclaimReturnedObject:
834  case CK_ARCExtendBlockObject:
835  case CK_CopyAndAutoreleaseBlockObject:
836  return nullptr;
837 
838  // These don't need to be handled here because Evaluate knows how to
839  // evaluate them in the cases where they can be folded.
840  case CK_BitCast:
841  case CK_ToVoid:
842  case CK_Dynamic:
843  case CK_LValueBitCast:
844  case CK_NullToMemberPointer:
845  case CK_UserDefinedConversion:
846  case CK_CPointerToObjCPointerCast:
847  case CK_BlockPointerToObjCPointerCast:
848  case CK_AnyPointerToBlockPointerCast:
849  case CK_ArrayToPointerDecay:
850  case CK_FunctionToPointerDecay:
851  case CK_BaseToDerived:
852  case CK_DerivedToBase:
853  case CK_UncheckedDerivedToBase:
854  case CK_MemberPointerToBoolean:
855  case CK_VectorSplat:
856  case CK_FloatingRealToComplex:
857  case CK_FloatingComplexToReal:
858  case CK_FloatingComplexToBoolean:
859  case CK_FloatingComplexCast:
860  case CK_FloatingComplexToIntegralComplex:
861  case CK_IntegralRealToComplex:
862  case CK_IntegralComplexToReal:
863  case CK_IntegralComplexToBoolean:
864  case CK_IntegralComplexCast:
865  case CK_IntegralComplexToFloatingComplex:
866  case CK_PointerToIntegral:
867  case CK_PointerToBoolean:
868  case CK_NullToPointer:
869  case CK_IntegralCast:
870  case CK_BooleanToSignedIntegral:
871  case CK_IntegralToPointer:
872  case CK_IntegralToBoolean:
873  case CK_IntegralToFloating:
874  case CK_FloatingToIntegral:
875  case CK_FloatingToBoolean:
876  case CK_FloatingCast:
877  case CK_FixedPointCast:
878  case CK_FixedPointToBoolean:
879  case CK_FixedPointToIntegral:
880  case CK_IntegralToFixedPoint:
881  case CK_ZeroToOCLOpaqueType:
882  return nullptr;
883  }
884  llvm_unreachable("Invalid CastKind");
885  }
886 
887  llvm::Constant *VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE, QualType T) {
888  // No need for a DefaultInitExprScope: we don't handle 'this' in a
889  // constant expression.
890  return Visit(DIE->getExpr(), T);
891  }
892 
893  llvm::Constant *VisitExprWithCleanups(ExprWithCleanups *E, QualType T) {
894  if (!E->cleanupsHaveSideEffects())
895  return Visit(E->getSubExpr(), T);
896  return nullptr;
897  }
898 
899  llvm::Constant *VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E,
900  QualType T) {
901  return Visit(E->GetTemporaryExpr(), T);
902  }
903 
904  llvm::Constant *EmitArrayInitialization(InitListExpr *ILE, QualType T) {
905  auto *CAT = CGM.getContext().getAsConstantArrayType(ILE->getType());
906  assert(CAT && "can't emit array init for non-constant-bound array");
907  unsigned NumInitElements = ILE->getNumInits();
908  unsigned NumElements = CAT->getSize().getZExtValue();
909 
910  // Initialising an array requires us to automatically
911  // initialise any elements that have not been initialised explicitly
912  unsigned NumInitableElts = std::min(NumInitElements, NumElements);
913 
914  QualType EltType = CAT->getElementType();
915 
916  // Initialize remaining array elements.
917  llvm::Constant *fillC = nullptr;
918  if (Expr *filler = ILE->getArrayFiller()) {
919  fillC = Emitter.tryEmitAbstractForMemory(filler, EltType);
920  if (!fillC)
921  return nullptr;
922  }
923 
924  // Copy initializer elements.
926  if (fillC && fillC->isNullValue())
927  Elts.reserve(NumInitableElts + 1);
928  else
929  Elts.reserve(NumElements);
930 
931  llvm::Type *CommonElementType = nullptr;
932  for (unsigned i = 0; i < NumInitableElts; ++i) {
933  Expr *Init = ILE->getInit(i);
934  llvm::Constant *C = Emitter.tryEmitPrivateForMemory(Init, EltType);
935  if (!C)
936  return nullptr;
937  if (i == 0)
938  CommonElementType = C->getType();
939  else if (C->getType() != CommonElementType)
940  CommonElementType = nullptr;
941  Elts.push_back(C);
942  }
943 
944  return EmitArrayConstant(CGM, CAT, CommonElementType, NumElements, Elts,
945  fillC);
946  }
947 
948  llvm::Constant *EmitRecordInitialization(InitListExpr *ILE, QualType T) {
949  return ConstStructBuilder::BuildStruct(Emitter, ILE, T);
950  }
951 
952  llvm::Constant *VisitImplicitValueInitExpr(ImplicitValueInitExpr* E,
953  QualType T) {
954  return CGM.EmitNullConstant(T);
955  }
956 
957  llvm::Constant *VisitInitListExpr(InitListExpr *ILE, QualType T) {
958  if (ILE->isTransparent())
959  return Visit(ILE->getInit(0), T);
960 
961  if (ILE->getType()->isArrayType())
962  return EmitArrayInitialization(ILE, T);
963 
964  if (ILE->getType()->isRecordType())
965  return EmitRecordInitialization(ILE, T);
966 
967  return nullptr;
968  }
969 
970  llvm::Constant *EmitDesignatedInitUpdater(llvm::Constant *Base,
971  InitListExpr *Updater,
972  QualType destType) {
973  if (auto destAT = CGM.getContext().getAsArrayType(destType)) {
974  llvm::ArrayType *AType = cast<llvm::ArrayType>(ConvertType(destType));
975  llvm::Type *ElemType = AType->getElementType();
976 
977  unsigned NumInitElements = Updater->getNumInits();
978  unsigned NumElements = AType->getNumElements();
979 
980  std::vector<llvm::Constant *> Elts;
981  Elts.reserve(NumElements);
982 
983  QualType destElemType = destAT->getElementType();
984 
985  if (auto DataArray = dyn_cast<llvm::ConstantDataArray>(Base))
986  for (unsigned i = 0; i != NumElements; ++i)
987  Elts.push_back(DataArray->getElementAsConstant(i));
988  else if (auto Array = dyn_cast<llvm::ConstantArray>(Base))
989  for (unsigned i = 0; i != NumElements; ++i)
990  Elts.push_back(Array->getOperand(i));
991  else
992  return nullptr; // FIXME: other array types not implemented
993 
994  llvm::Constant *fillC = nullptr;
995  if (Expr *filler = Updater->getArrayFiller())
996  if (!isa<NoInitExpr>(filler))
997  fillC = Emitter.tryEmitAbstractForMemory(filler, destElemType);
998  bool RewriteType = (fillC && fillC->getType() != ElemType);
999 
1000  for (unsigned i = 0; i != NumElements; ++i) {
1001  Expr *Init = nullptr;
1002  if (i < NumInitElements)
1003  Init = Updater->getInit(i);
1004 
1005  if (!Init && fillC)
1006  Elts[i] = fillC;
1007  else if (!Init || isa<NoInitExpr>(Init))
1008  ; // Do nothing.
1009  else if (InitListExpr *ChildILE = dyn_cast<InitListExpr>(Init))
1010  Elts[i] = EmitDesignatedInitUpdater(Elts[i], ChildILE, destElemType);
1011  else
1012  Elts[i] = Emitter.tryEmitPrivateForMemory(Init, destElemType);
1013 
1014  if (!Elts[i])
1015  return nullptr;
1016  RewriteType |= (Elts[i]->getType() != ElemType);
1017  }
1018 
1019  if (RewriteType) {
1020  std::vector<llvm::Type *> Types;
1021  Types.reserve(NumElements);
1022  for (unsigned i = 0; i != NumElements; ++i)
1023  Types.push_back(Elts[i]->getType());
1024  llvm::StructType *SType = llvm::StructType::get(AType->getContext(),
1025  Types, true);
1026  return llvm::ConstantStruct::get(SType, Elts);
1027  }
1028 
1029  return llvm::ConstantArray::get(AType, Elts);
1030  }
1031 
1032  if (destType->isRecordType())
1033  return ConstStructBuilder::BuildStruct(Emitter, this, Base, Updater,
1034  destType);
1035 
1036  return nullptr;
1037  }
1038 
1039  llvm::Constant *VisitDesignatedInitUpdateExpr(DesignatedInitUpdateExpr *E,
1040  QualType destType) {
1041  auto C = Visit(E->getBase(), destType);
1042  if (!C) return nullptr;
1043  return EmitDesignatedInitUpdater(C, E->getUpdater(), destType);
1044  }
1045 
1046  llvm::Constant *VisitCXXConstructExpr(CXXConstructExpr *E, QualType Ty) {
1047  if (!E->getConstructor()->isTrivial())
1048  return nullptr;
1049 
1050  // FIXME: We should not have to call getBaseElementType here.
1051  const RecordType *RT =
1053  const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
1054 
1055  // If the class doesn't have a trivial destructor, we can't emit it as a
1056  // constant expr.
1057  if (!RD->hasTrivialDestructor())
1058  return nullptr;
1059 
1060  // Only copy and default constructors can be trivial.
1061 
1062 
1063  if (E->getNumArgs()) {
1064  assert(E->getNumArgs() == 1 && "trivial ctor with > 1 argument");
1065  assert(E->getConstructor()->isCopyOrMoveConstructor() &&
1066  "trivial ctor has argument but isn't a copy/move ctor");
1067 
1068  Expr *Arg = E->getArg(0);
1069  assert(CGM.getContext().hasSameUnqualifiedType(Ty, Arg->getType()) &&
1070  "argument to copy ctor is of wrong type");
1071 
1072  return Visit(Arg, Ty);
1073  }
1074 
1075  return CGM.EmitNullConstant(Ty);
1076  }
1077 
1078  llvm::Constant *VisitStringLiteral(StringLiteral *E, QualType T) {
1079  // This is a string literal initializing an array in an initializer.
1080  return CGM.GetConstantArrayFromStringLiteral(E);
1081  }
1082 
1083  llvm::Constant *VisitObjCEncodeExpr(ObjCEncodeExpr *E, QualType T) {
1084  // This must be an @encode initializing an array in a static initializer.
1085  // Don't emit it as the address of the string, emit the string data itself
1086  // as an inline array.
1087  std::string Str;
1089  const ConstantArrayType *CAT = CGM.getContext().getAsConstantArrayType(T);
1090 
1091  // Resize the string to the right size, adding zeros at the end, or
1092  // truncating as needed.
1093  Str.resize(CAT->getSize().getZExtValue(), '\0');
1094  return llvm::ConstantDataArray::getString(VMContext, Str, false);
1095  }
1096 
1097  llvm::Constant *VisitUnaryExtension(const UnaryOperator *E, QualType T) {
1098  return Visit(E->getSubExpr(), T);
1099  }
1100 
1101  // Utility methods
1102  llvm::Type *ConvertType(QualType T) {
1103  return CGM.getTypes().ConvertType(T);
1104  }
1105 };
1106 
1107 } // end anonymous namespace.
1108 
1109 bool ConstStructBuilder::Build(ConstExprEmitter *ExprEmitter,
1110  llvm::Constant *Base,
1111  InitListExpr *Updater) {
1112  assert(Base && "base expression should not be empty");
1113 
1114  QualType ExprType = Updater->getType();
1115  RecordDecl *RD = ExprType->getAs<RecordType>()->getDecl();
1116  const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
1117  const llvm::StructLayout *BaseLayout = CGM.getDataLayout().getStructLayout(
1118  cast<llvm::StructType>(Base->getType()));
1119  unsigned FieldNo = -1;
1120  unsigned ElementNo = 0;
1121 
1122  // Bail out if we have base classes. We could support these, but they only
1123  // arise in C++1z where we will have already constant folded most interesting
1124  // cases. FIXME: There are still a few more cases we can handle this way.
1125  if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD))
1126  if (CXXRD->getNumBases())
1127  return false;
1128 
1129  for (FieldDecl *Field : RD->fields()) {
1130  ++FieldNo;
1131 
1132  if (RD->isUnion() && Updater->getInitializedFieldInUnion() != Field)
1133  continue;
1134 
1135  // Skip anonymous bitfields.
1136  if (Field->isUnnamedBitfield())
1137  continue;
1138 
1139  llvm::Constant *EltInit = Base->getAggregateElement(ElementNo);
1140 
1141  // Bail out if the type of the ConstantStruct does not have the same layout
1142  // as the type of the InitListExpr.
1143  if (CGM.getTypes().ConvertType(Field->getType()) != EltInit->getType() ||
1144  Layout.getFieldOffset(ElementNo) !=
1145  BaseLayout->getElementOffsetInBits(ElementNo))
1146  return false;
1147 
1148  // Get the initializer. If we encounter an empty field or a NoInitExpr,
1149  // we use values from the base expression.
1150  Expr *Init = nullptr;
1151  if (ElementNo < Updater->getNumInits())
1152  Init = Updater->getInit(ElementNo);
1153 
1154  if (!Init || isa<NoInitExpr>(Init))
1155  ; // Do nothing.
1156  else if (InitListExpr *ChildILE = dyn_cast<InitListExpr>(Init))
1157  EltInit = ExprEmitter->EmitDesignatedInitUpdater(EltInit, ChildILE,
1158  Field->getType());
1159  else
1160  EltInit = Emitter.tryEmitPrivateForMemory(Init, Field->getType());
1161 
1162  ++ElementNo;
1163 
1164  if (!EltInit)
1165  return false;
1166 
1167  if (!Field->isBitField())
1168  AppendField(Field, Layout.getFieldOffset(FieldNo), EltInit);
1169  else if (llvm::ConstantInt *CI = dyn_cast<llvm::ConstantInt>(EltInit))
1170  AppendBitField(Field, Layout.getFieldOffset(FieldNo), CI);
1171  else
1172  // Initializing a bitfield with a non-trivial constant?
1173  return false;
1174  }
1175 
1176  return true;
1177 }
1178 
1179 llvm::Constant *ConstantEmitter::validateAndPopAbstract(llvm::Constant *C,
1180  AbstractState saved) {
1181  Abstract = saved.OldValue;
1182 
1183  assert(saved.OldPlaceholdersSize == PlaceholderAddresses.size() &&
1184  "created a placeholder while doing an abstract emission?");
1185 
1186  // No validation necessary for now.
1187  // No cleanup to do for now.
1188  return C;
1189 }
1190 
1191 llvm::Constant *
1193  auto state = pushAbstract();
1194  auto C = tryEmitPrivateForVarInit(D);
1195  return validateAndPopAbstract(C, state);
1196 }
1197 
1198 llvm::Constant *
1200  auto state = pushAbstract();
1201  auto C = tryEmitPrivate(E, destType);
1202  return validateAndPopAbstract(C, state);
1203 }
1204 
1205 llvm::Constant *
1207  auto state = pushAbstract();
1208  auto C = tryEmitPrivate(value, destType);
1209  return validateAndPopAbstract(C, state);
1210 }
1211 
1212 llvm::Constant *
1214  auto state = pushAbstract();
1215  auto C = tryEmitPrivate(E, destType);
1216  C = validateAndPopAbstract(C, state);
1217  if (!C) {
1218  CGM.Error(E->getExprLoc(),
1219  "internal error: could not emit constant value \"abstractly\"");
1220  C = CGM.EmitNullConstant(destType);
1221  }
1222  return C;
1223 }
1224 
1225 llvm::Constant *
1227  QualType destType) {
1228  auto state = pushAbstract();
1229  auto C = tryEmitPrivate(value, destType);
1230  C = validateAndPopAbstract(C, state);
1231  if (!C) {
1232  CGM.Error(loc,
1233  "internal error: could not emit constant value \"abstractly\"");
1234  C = CGM.EmitNullConstant(destType);
1235  }
1236  return C;
1237 }
1238 
1240  initializeNonAbstract(D.getType().getAddressSpace());
1241  return markIfFailed(tryEmitPrivateForVarInit(D));
1242 }
1243 
1245  LangAS destAddrSpace,
1246  QualType destType) {
1247  initializeNonAbstract(destAddrSpace);
1248  return markIfFailed(tryEmitPrivateForMemory(E, destType));
1249 }
1250 
1251 llvm::Constant *ConstantEmitter::emitForInitializer(const APValue &value,
1252  LangAS destAddrSpace,
1253  QualType destType) {
1254  initializeNonAbstract(destAddrSpace);
1255  auto C = tryEmitPrivateForMemory(value, destType);
1256  assert(C && "couldn't emit constant value non-abstractly?");
1257  return C;
1258 }
1259 
1261  assert(!Abstract && "cannot get current address for abstract constant");
1262 
1263 
1264 
1265  // Make an obviously ill-formed global that should blow up compilation
1266  // if it survives.
1267  auto global = new llvm::GlobalVariable(CGM.getModule(), CGM.Int8Ty, true,
1268  llvm::GlobalValue::PrivateLinkage,
1269  /*init*/ nullptr,
1270  /*name*/ "",
1271  /*before*/ nullptr,
1272  llvm::GlobalVariable::NotThreadLocal,
1273  CGM.getContext().getTargetAddressSpace(DestAddressSpace));
1274 
1275  PlaceholderAddresses.push_back(std::make_pair(nullptr, global));
1276 
1277  return global;
1278 }
1279 
1281  llvm::GlobalValue *placeholder) {
1282  assert(!PlaceholderAddresses.empty());
1283  assert(PlaceholderAddresses.back().first == nullptr);
1284  assert(PlaceholderAddresses.back().second == placeholder);
1285  PlaceholderAddresses.back().first = signal;
1286 }
1287 
1288 namespace {
1289  struct ReplacePlaceholders {
1290  CodeGenModule &CGM;
1291 
1292  /// The base address of the global.
1293  llvm::Constant *Base;
1294  llvm::Type *BaseValueTy = nullptr;
1295 
1296  /// The placeholder addresses that were registered during emission.
1297  llvm::DenseMap<llvm::Constant*, llvm::GlobalVariable*> PlaceholderAddresses;
1298 
1299  /// The locations of the placeholder signals.
1300  llvm::DenseMap<llvm::GlobalVariable*, llvm::Constant*> Locations;
1301 
1302  /// The current index stack. We use a simple unsigned stack because
1303  /// we assume that placeholders will be relatively sparse in the
1304  /// initializer, but we cache the index values we find just in case.
1307 
1308  ReplacePlaceholders(CodeGenModule &CGM, llvm::Constant *base,
1309  ArrayRef<std::pair<llvm::Constant*,
1310  llvm::GlobalVariable*>> addresses)
1311  : CGM(CGM), Base(base),
1312  PlaceholderAddresses(addresses.begin(), addresses.end()) {
1313  }
1314 
1315  void replaceInInitializer(llvm::Constant *init) {
1316  // Remember the type of the top-most initializer.
1317  BaseValueTy = init->getType();
1318 
1319  // Initialize the stack.
1320  Indices.push_back(0);
1321  IndexValues.push_back(nullptr);
1322 
1323  // Recurse into the initializer.
1324  findLocations(init);
1325 
1326  // Check invariants.
1327  assert(IndexValues.size() == Indices.size() && "mismatch");
1328  assert(Indices.size() == 1 && "didn't pop all indices");
1329 
1330  // Do the replacement; this basically invalidates 'init'.
1331  assert(Locations.size() == PlaceholderAddresses.size() &&
1332  "missed a placeholder?");
1333 
1334  // We're iterating over a hashtable, so this would be a source of
1335  // non-determinism in compiler output *except* that we're just
1336  // messing around with llvm::Constant structures, which never itself
1337  // does anything that should be visible in compiler output.
1338  for (auto &entry : Locations) {
1339  assert(entry.first->getParent() == nullptr && "not a placeholder!");
1340  entry.first->replaceAllUsesWith(entry.second);
1341  entry.first->eraseFromParent();
1342  }
1343  }
1344 
1345  private:
1346  void findLocations(llvm::Constant *init) {
1347  // Recurse into aggregates.
1348  if (auto agg = dyn_cast<llvm::ConstantAggregate>(init)) {
1349  for (unsigned i = 0, e = agg->getNumOperands(); i != e; ++i) {
1350  Indices.push_back(i);
1351  IndexValues.push_back(nullptr);
1352 
1353  findLocations(agg->getOperand(i));
1354 
1355  IndexValues.pop_back();
1356  Indices.pop_back();
1357  }
1358  return;
1359  }
1360 
1361  // Otherwise, check for registered constants.
1362  while (true) {
1363  auto it = PlaceholderAddresses.find(init);
1364  if (it != PlaceholderAddresses.end()) {
1365  setLocation(it->second);
1366  break;
1367  }
1368 
1369  // Look through bitcasts or other expressions.
1370  if (auto expr = dyn_cast<llvm::ConstantExpr>(init)) {
1371  init = expr->getOperand(0);
1372  } else {
1373  break;
1374  }
1375  }
1376  }
1377 
1378  void setLocation(llvm::GlobalVariable *placeholder) {
1379  assert(Locations.find(placeholder) == Locations.end() &&
1380  "already found location for placeholder!");
1381 
1382  // Lazily fill in IndexValues with the values from Indices.
1383  // We do this in reverse because we should always have a strict
1384  // prefix of indices from the start.
1385  assert(Indices.size() == IndexValues.size());
1386  for (size_t i = Indices.size() - 1; i != size_t(-1); --i) {
1387  if (IndexValues[i]) {
1388 #ifndef NDEBUG
1389  for (size_t j = 0; j != i + 1; ++j) {
1390  assert(IndexValues[j] &&
1391  isa<llvm::ConstantInt>(IndexValues[j]) &&
1392  cast<llvm::ConstantInt>(IndexValues[j])->getZExtValue()
1393  == Indices[j]);
1394  }
1395 #endif
1396  break;
1397  }
1398 
1399  IndexValues[i] = llvm::ConstantInt::get(CGM.Int32Ty, Indices[i]);
1400  }
1401 
1402  // Form a GEP and then bitcast to the placeholder type so that the
1403  // replacement will succeed.
1404  llvm::Constant *location =
1405  llvm::ConstantExpr::getInBoundsGetElementPtr(BaseValueTy,
1406  Base, IndexValues);
1407  location = llvm::ConstantExpr::getBitCast(location,
1408  placeholder->getType());
1409 
1410  Locations.insert({placeholder, location});
1411  }
1412  };
1413 }
1414 
1415 void ConstantEmitter::finalize(llvm::GlobalVariable *global) {
1416  assert(InitializedNonAbstract &&
1417  "finalizing emitter that was used for abstract emission?");
1418  assert(!Finalized && "finalizing emitter multiple times");
1419  assert(global->getInitializer());
1420 
1421  // Note that we might also be Failed.
1422  Finalized = true;
1423 
1424  if (!PlaceholderAddresses.empty()) {
1425  ReplacePlaceholders(CGM, global, PlaceholderAddresses)
1426  .replaceInInitializer(global->getInitializer());
1427  PlaceholderAddresses.clear(); // satisfy
1428  }
1429 }
1430 
1432  assert((!InitializedNonAbstract || Finalized || Failed) &&
1433  "not finalized after being initialized for non-abstract emission");
1434  assert(PlaceholderAddresses.empty() && "unhandled placeholders");
1435 }
1436 
1438  if (auto AT = type->getAs<AtomicType>()) {
1439  return CGM.getContext().getQualifiedType(AT->getValueType(),
1440  type.getQualifiers());
1441  }
1442  return type;
1443 }
1444 
1446  // Make a quick check if variable can be default NULL initialized
1447  // and avoid going through rest of code which may do, for c++11,
1448  // initialization of memory to all NULLs.
1449  if (!D.hasLocalStorage()) {
1451  if (Ty->isRecordType())
1452  if (const CXXConstructExpr *E =
1453  dyn_cast_or_null<CXXConstructExpr>(D.getInit())) {
1454  const CXXConstructorDecl *CD = E->getConstructor();
1455  if (CD->isTrivial() && CD->isDefaultConstructor())
1456  return CGM.EmitNullConstant(D.getType());
1457  }
1458  InConstantContext = true;
1459  }
1460 
1461  QualType destType = D.getType();
1462 
1463  // Try to emit the initializer. Note that this can allow some things that
1464  // are not allowed by tryEmitPrivateForMemory alone.
1465  if (auto value = D.evaluateValue()) {
1466  return tryEmitPrivateForMemory(*value, destType);
1467  }
1468 
1469  // FIXME: Implement C++11 [basic.start.init]p2: if the initializer of a
1470  // reference is a constant expression, and the reference binds to a temporary,
1471  // then constant initialization is performed. ConstExprEmitter will
1472  // incorrectly emit a prvalue constant in this case, and the calling code
1473  // interprets that as the (pointer) value of the reference, rather than the
1474  // desired value of the referee.
1475  if (destType->isReferenceType())
1476  return nullptr;
1477 
1478  const Expr *E = D.getInit();
1479  assert(E && "No initializer to emit");
1480 
1481  auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1482  auto C =
1483  ConstExprEmitter(*this).Visit(const_cast<Expr*>(E), nonMemoryDestType);
1484  return (C ? emitForMemory(C, destType) : nullptr);
1485 }
1486 
1487 llvm::Constant *
1489  auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1490  auto C = tryEmitAbstract(E, nonMemoryDestType);
1491  return (C ? emitForMemory(C, destType) : nullptr);
1492 }
1493 
1494 llvm::Constant *
1496  QualType destType) {
1497  auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1498  auto C = tryEmitAbstract(value, nonMemoryDestType);
1499  return (C ? emitForMemory(C, destType) : nullptr);
1500 }
1501 
1503  QualType destType) {
1504  auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1505  llvm::Constant *C = tryEmitPrivate(E, nonMemoryDestType);
1506  return (C ? emitForMemory(C, destType) : nullptr);
1507 }
1508 
1510  QualType destType) {
1511  auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1512  auto C = tryEmitPrivate(value, nonMemoryDestType);
1513  return (C ? emitForMemory(C, destType) : nullptr);
1514 }
1515 
1517  llvm::Constant *C,
1518  QualType destType) {
1519  // For an _Atomic-qualified constant, we may need to add tail padding.
1520  if (auto AT = destType->getAs<AtomicType>()) {
1521  QualType destValueType = AT->getValueType();
1522  C = emitForMemory(CGM, C, destValueType);
1523 
1524  uint64_t innerSize = CGM.getContext().getTypeSize(destValueType);
1525  uint64_t outerSize = CGM.getContext().getTypeSize(destType);
1526  if (innerSize == outerSize)
1527  return C;
1528 
1529  assert(innerSize < outerSize && "emitted over-large constant for atomic");
1530  llvm::Constant *elts[] = {
1531  C,
1532  llvm::ConstantAggregateZero::get(
1533  llvm::ArrayType::get(CGM.Int8Ty, (outerSize - innerSize) / 8))
1534  };
1535  return llvm::ConstantStruct::getAnon(elts);
1536  }
1537 
1538  // Zero-extend bool.
1539  if (C->getType()->isIntegerTy(1)) {
1540  llvm::Type *boolTy = CGM.getTypes().ConvertTypeForMem(destType);
1541  return llvm::ConstantExpr::getZExt(C, boolTy);
1542  }
1543 
1544  return C;
1545 }
1546 
1547 llvm::Constant *ConstantEmitter::tryEmitPrivate(const Expr *E,
1548  QualType destType) {
1549  Expr::EvalResult Result;
1550 
1551  bool Success = false;
1552 
1553  if (destType->isReferenceType())
1554  Success = E->EvaluateAsLValue(Result, CGM.getContext());
1555  else
1556  Success = E->EvaluateAsRValue(Result, CGM.getContext(), InConstantContext);
1557 
1558  llvm::Constant *C;
1559  if (Success && !Result.HasSideEffects)
1560  C = tryEmitPrivate(Result.Val, destType);
1561  else
1562  C = ConstExprEmitter(*this).Visit(const_cast<Expr*>(E), destType);
1563 
1564  return C;
1565 }
1566 
1567 llvm::Constant *CodeGenModule::getNullPointer(llvm::PointerType *T, QualType QT) {
1568  return getTargetCodeGenInfo().getNullPointer(*this, T, QT);
1569 }
1570 
1571 namespace {
1572 /// A struct which can be used to peephole certain kinds of finalization
1573 /// that normally happen during l-value emission.
1574 struct ConstantLValue {
1575  llvm::Constant *Value;
1576  bool HasOffsetApplied;
1577 
1578  /*implicit*/ ConstantLValue(llvm::Constant *value,
1579  bool hasOffsetApplied = false)
1580  : Value(value), HasOffsetApplied(false) {}
1581 
1582  /*implicit*/ ConstantLValue(ConstantAddress address)
1583  : ConstantLValue(address.getPointer()) {}
1584 };
1585 
1586 /// A helper class for emitting constant l-values.
1587 class ConstantLValueEmitter : public ConstStmtVisitor<ConstantLValueEmitter,
1588  ConstantLValue> {
1589  CodeGenModule &CGM;
1590  ConstantEmitter &Emitter;
1591  const APValue &Value;
1592  QualType DestType;
1593 
1594  // Befriend StmtVisitorBase so that we don't have to expose Visit*.
1595  friend StmtVisitorBase;
1596 
1597 public:
1598  ConstantLValueEmitter(ConstantEmitter &emitter, const APValue &value,
1599  QualType destType)
1600  : CGM(emitter.CGM), Emitter(emitter), Value(value), DestType(destType) {}
1601 
1602  llvm::Constant *tryEmit();
1603 
1604 private:
1605  llvm::Constant *tryEmitAbsolute(llvm::Type *destTy);
1606  ConstantLValue tryEmitBase(const APValue::LValueBase &base);
1607 
1608  ConstantLValue VisitStmt(const Stmt *S) { return nullptr; }
1609  ConstantLValue VisitConstantExpr(const ConstantExpr *E);
1610  ConstantLValue VisitCompoundLiteralExpr(const CompoundLiteralExpr *E);
1611  ConstantLValue VisitStringLiteral(const StringLiteral *E);
1612  ConstantLValue VisitObjCBoxedExpr(const ObjCBoxedExpr *E);
1613  ConstantLValue VisitObjCEncodeExpr(const ObjCEncodeExpr *E);
1614  ConstantLValue VisitObjCStringLiteral(const ObjCStringLiteral *E);
1615  ConstantLValue VisitPredefinedExpr(const PredefinedExpr *E);
1616  ConstantLValue VisitAddrLabelExpr(const AddrLabelExpr *E);
1617  ConstantLValue VisitCallExpr(const CallExpr *E);
1618  ConstantLValue VisitBlockExpr(const BlockExpr *E);
1619  ConstantLValue VisitCXXTypeidExpr(const CXXTypeidExpr *E);
1620  ConstantLValue VisitCXXUuidofExpr(const CXXUuidofExpr *E);
1621  ConstantLValue VisitMaterializeTemporaryExpr(
1622  const MaterializeTemporaryExpr *E);
1623 
1624  bool hasNonZeroOffset() const {
1625  return !Value.getLValueOffset().isZero();
1626  }
1627 
1628  /// Return the value offset.
1629  llvm::Constant *getOffset() {
1630  return llvm::ConstantInt::get(CGM.Int64Ty,
1631  Value.getLValueOffset().getQuantity());
1632  }
1633 
1634  /// Apply the value offset to the given constant.
1635  llvm::Constant *applyOffset(llvm::Constant *C) {
1636  if (!hasNonZeroOffset())
1637  return C;
1638 
1639  llvm::Type *origPtrTy = C->getType();
1640  unsigned AS = origPtrTy->getPointerAddressSpace();
1641  llvm::Type *charPtrTy = CGM.Int8Ty->getPointerTo(AS);
1642  C = llvm::ConstantExpr::getBitCast(C, charPtrTy);
1643  C = llvm::ConstantExpr::getGetElementPtr(CGM.Int8Ty, C, getOffset());
1644  C = llvm::ConstantExpr::getPointerCast(C, origPtrTy);
1645  return C;
1646  }
1647 };
1648 
1649 }
1650 
1651 llvm::Constant *ConstantLValueEmitter::tryEmit() {
1652  const APValue::LValueBase &base = Value.getLValueBase();
1653 
1654  // The destination type should be a pointer or reference
1655  // type, but it might also be a cast thereof.
1656  //
1657  // FIXME: the chain of casts required should be reflected in the APValue.
1658  // We need this in order to correctly handle things like a ptrtoint of a
1659  // non-zero null pointer and addrspace casts that aren't trivially
1660  // represented in LLVM IR.
1661  auto destTy = CGM.getTypes().ConvertTypeForMem(DestType);
1662  assert(isa<llvm::IntegerType>(destTy) || isa<llvm::PointerType>(destTy));
1663 
1664  // If there's no base at all, this is a null or absolute pointer,
1665  // possibly cast back to an integer type.
1666  if (!base) {
1667  return tryEmitAbsolute(destTy);
1668  }
1669 
1670  // Otherwise, try to emit the base.
1671  ConstantLValue result = tryEmitBase(base);
1672 
1673  // If that failed, we're done.
1674  llvm::Constant *value = result.Value;
1675  if (!value) return nullptr;
1676 
1677  // Apply the offset if necessary and not already done.
1678  if (!result.HasOffsetApplied) {
1679  value = applyOffset(value);
1680  }
1681 
1682  // Convert to the appropriate type; this could be an lvalue for
1683  // an integer. FIXME: performAddrSpaceCast
1684  if (isa<llvm::PointerType>(destTy))
1685  return llvm::ConstantExpr::getPointerCast(value, destTy);
1686 
1687  return llvm::ConstantExpr::getPtrToInt(value, destTy);
1688 }
1689 
1690 /// Try to emit an absolute l-value, such as a null pointer or an integer
1691 /// bitcast to pointer type.
1692 llvm::Constant *
1693 ConstantLValueEmitter::tryEmitAbsolute(llvm::Type *destTy) {
1694  // If we're producing a pointer, this is easy.
1695  auto destPtrTy = cast<llvm::PointerType>(destTy);
1696  if (Value.isNullPointer()) {
1697  // FIXME: integer offsets from non-zero null pointers.
1698  return CGM.getNullPointer(destPtrTy, DestType);
1699  }
1700 
1701  // Convert the integer to a pointer-sized integer before converting it
1702  // to a pointer.
1703  // FIXME: signedness depends on the original integer type.
1704  auto intptrTy = CGM.getDataLayout().getIntPtrType(destPtrTy);
1705  llvm::Constant *C;
1706  C = llvm::ConstantExpr::getIntegerCast(getOffset(), intptrTy,
1707  /*isSigned*/ false);
1708  C = llvm::ConstantExpr::getIntToPtr(C, destPtrTy);
1709  return C;
1710 }
1711 
1712 ConstantLValue
1713 ConstantLValueEmitter::tryEmitBase(const APValue::LValueBase &base) {
1714  // Handle values.
1715  if (const ValueDecl *D = base.dyn_cast<const ValueDecl*>()) {
1716  if (D->hasAttr<WeakRefAttr>())
1717  return CGM.GetWeakRefReference(D).getPointer();
1718 
1719  if (auto FD = dyn_cast<FunctionDecl>(D))
1720  return CGM.GetAddrOfFunction(FD);
1721 
1722  if (auto VD = dyn_cast<VarDecl>(D)) {
1723  // We can never refer to a variable with local storage.
1724  if (!VD->hasLocalStorage()) {
1725  if (VD->isFileVarDecl() || VD->hasExternalStorage())
1726  return CGM.GetAddrOfGlobalVar(VD);
1727 
1728  if (VD->isLocalVarDecl()) {
1729  return CGM.getOrCreateStaticVarDecl(
1730  *VD, CGM.getLLVMLinkageVarDefinition(VD, /*isConstant=*/false));
1731  }
1732  }
1733  }
1734 
1735  return nullptr;
1736  }
1737 
1738  // Handle typeid(T).
1739  if (TypeInfoLValue TI = base.dyn_cast<TypeInfoLValue>()) {
1740  llvm::Type *StdTypeInfoPtrTy =
1741  CGM.getTypes().ConvertType(base.getTypeInfoType())->getPointerTo();
1742  llvm::Constant *TypeInfo =
1743  CGM.GetAddrOfRTTIDescriptor(QualType(TI.getType(), 0));
1744  if (TypeInfo->getType() != StdTypeInfoPtrTy)
1745  TypeInfo = llvm::ConstantExpr::getBitCast(TypeInfo, StdTypeInfoPtrTy);
1746  return TypeInfo;
1747  }
1748 
1749  // Otherwise, it must be an expression.
1750  return Visit(base.get<const Expr*>());
1751 }
1752 
1753 ConstantLValue
1754 ConstantLValueEmitter::VisitConstantExpr(const ConstantExpr *E) {
1755  return Visit(E->getSubExpr());
1756 }
1757 
1758 ConstantLValue
1759 ConstantLValueEmitter::VisitCompoundLiteralExpr(const CompoundLiteralExpr *E) {
1760  return tryEmitGlobalCompoundLiteral(CGM, Emitter.CGF, E);
1761 }
1762 
1763 ConstantLValue
1764 ConstantLValueEmitter::VisitStringLiteral(const StringLiteral *E) {
1765  return CGM.GetAddrOfConstantStringFromLiteral(E);
1766 }
1767 
1768 ConstantLValue
1769 ConstantLValueEmitter::VisitObjCEncodeExpr(const ObjCEncodeExpr *E) {
1771 }
1772 
1773 static ConstantLValue emitConstantObjCStringLiteral(const StringLiteral *S,
1774  QualType T,
1775  CodeGenModule &CGM) {
1776  auto C = CGM.getObjCRuntime().GenerateConstantString(S);
1777  return C.getElementBitCast(CGM.getTypes().ConvertTypeForMem(T));
1778 }
1779 
1780 ConstantLValue
1781 ConstantLValueEmitter::VisitObjCStringLiteral(const ObjCStringLiteral *E) {
1782  return emitConstantObjCStringLiteral(E->getString(), E->getType(), CGM);
1783 }
1784 
1785 ConstantLValue
1786 ConstantLValueEmitter::VisitObjCBoxedExpr(const ObjCBoxedExpr *E) {
1787  assert(E->isExpressibleAsConstantInitializer() &&
1788  "this boxed expression can't be emitted as a compile-time constant");
1789  auto *SL = cast<StringLiteral>(E->getSubExpr()->IgnoreParenCasts());
1790  return emitConstantObjCStringLiteral(SL, E->getType(), CGM);
1791 }
1792 
1793 ConstantLValue
1794 ConstantLValueEmitter::VisitPredefinedExpr(const PredefinedExpr *E) {
1796 }
1797 
1798 ConstantLValue
1799 ConstantLValueEmitter::VisitAddrLabelExpr(const AddrLabelExpr *E) {
1800  assert(Emitter.CGF && "Invalid address of label expression outside function");
1801  llvm::Constant *Ptr = Emitter.CGF->GetAddrOfLabel(E->getLabel());
1802  Ptr = llvm::ConstantExpr::getBitCast(Ptr,
1803  CGM.getTypes().ConvertType(E->getType()));
1804  return Ptr;
1805 }
1806 
1807 ConstantLValue
1808 ConstantLValueEmitter::VisitCallExpr(const CallExpr *E) {
1809  unsigned builtin = E->getBuiltinCallee();
1810  if (builtin != Builtin::BI__builtin___CFStringMakeConstantString &&
1811  builtin != Builtin::BI__builtin___NSStringMakeConstantString)
1812  return nullptr;
1813 
1814  auto literal = cast<StringLiteral>(E->getArg(0)->IgnoreParenCasts());
1815  if (builtin == Builtin::BI__builtin___NSStringMakeConstantString) {
1816  return CGM.getObjCRuntime().GenerateConstantString(literal);
1817  } else {
1818  // FIXME: need to deal with UCN conversion issues.
1819  return CGM.GetAddrOfConstantCFString(literal);
1820  }
1821 }
1822 
1823 ConstantLValue
1824 ConstantLValueEmitter::VisitBlockExpr(const BlockExpr *E) {
1825  StringRef functionName;
1826  if (auto CGF = Emitter.CGF)
1827  functionName = CGF->CurFn->getName();
1828  else
1829  functionName = "global";
1830 
1831  return CGM.GetAddrOfGlobalBlock(E, functionName);
1832 }
1833 
1834 ConstantLValue
1835 ConstantLValueEmitter::VisitCXXTypeidExpr(const CXXTypeidExpr *E) {
1836  QualType T;
1837  if (E->isTypeOperand())
1838  T = E->getTypeOperand(CGM.getContext());
1839  else
1840  T = E->getExprOperand()->getType();
1841  return CGM.GetAddrOfRTTIDescriptor(T);
1842 }
1843 
1844 ConstantLValue
1845 ConstantLValueEmitter::VisitCXXUuidofExpr(const CXXUuidofExpr *E) {
1846  return CGM.GetAddrOfUuidDescriptor(E);
1847 }
1848 
1849 ConstantLValue
1850 ConstantLValueEmitter::VisitMaterializeTemporaryExpr(
1851  const MaterializeTemporaryExpr *E) {
1852  assert(E->getStorageDuration() == SD_Static);
1853  SmallVector<const Expr *, 2> CommaLHSs;
1855  const Expr *Inner = E->GetTemporaryExpr()
1856  ->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
1857  return CGM.GetAddrOfGlobalTemporary(E, Inner);
1858 }
1859 
1861  QualType DestType) {
1862  switch (Value.getKind()) {
1863  case APValue::None:
1865  // Out-of-lifetime and indeterminate values can be modeled as 'undef'.
1866  return llvm::UndefValue::get(CGM.getTypes().ConvertType(DestType));
1867  case APValue::LValue:
1868  return ConstantLValueEmitter(*this, Value, DestType).tryEmit();
1869  case APValue::Int:
1870  return llvm::ConstantInt::get(CGM.getLLVMContext(), Value.getInt());
1871  case APValue::FixedPoint:
1872  return llvm::ConstantInt::get(CGM.getLLVMContext(),
1873  Value.getFixedPoint().getValue());
1874  case APValue::ComplexInt: {
1875  llvm::Constant *Complex[2];
1876 
1877  Complex[0] = llvm::ConstantInt::get(CGM.getLLVMContext(),
1878  Value.getComplexIntReal());
1879  Complex[1] = llvm::ConstantInt::get(CGM.getLLVMContext(),
1880  Value.getComplexIntImag());
1881 
1882  // FIXME: the target may want to specify that this is packed.
1883  llvm::StructType *STy =
1884  llvm::StructType::get(Complex[0]->getType(), Complex[1]->getType());
1885  return llvm::ConstantStruct::get(STy, Complex);
1886  }
1887  case APValue::Float: {
1888  const llvm::APFloat &Init = Value.getFloat();
1889  if (&Init.getSemantics() == &llvm::APFloat::IEEEhalf() &&
1890  !CGM.getContext().getLangOpts().NativeHalfType &&
1892  return llvm::ConstantInt::get(CGM.getLLVMContext(),
1893  Init.bitcastToAPInt());
1894  else
1895  return llvm::ConstantFP::get(CGM.getLLVMContext(), Init);
1896  }
1897  case APValue::ComplexFloat: {
1898  llvm::Constant *Complex[2];
1899 
1900  Complex[0] = llvm::ConstantFP::get(CGM.getLLVMContext(),
1901  Value.getComplexFloatReal());
1902  Complex[1] = llvm::ConstantFP::get(CGM.getLLVMContext(),
1903  Value.getComplexFloatImag());
1904 
1905  // FIXME: the target may want to specify that this is packed.
1906  llvm::StructType *STy =
1907  llvm::StructType::get(Complex[0]->getType(), Complex[1]->getType());
1908  return llvm::ConstantStruct::get(STy, Complex);
1909  }
1910  case APValue::Vector: {
1911  unsigned NumElts = Value.getVectorLength();
1913 
1914  for (unsigned I = 0; I != NumElts; ++I) {
1915  const APValue &Elt = Value.getVectorElt(I);
1916  if (Elt.isInt())
1917  Inits[I] = llvm::ConstantInt::get(CGM.getLLVMContext(), Elt.getInt());
1918  else if (Elt.isFloat())
1919  Inits[I] = llvm::ConstantFP::get(CGM.getLLVMContext(), Elt.getFloat());
1920  else
1921  llvm_unreachable("unsupported vector element type");
1922  }
1923  return llvm::ConstantVector::get(Inits);
1924  }
1925  case APValue::AddrLabelDiff: {
1926  const AddrLabelExpr *LHSExpr = Value.getAddrLabelDiffLHS();
1927  const AddrLabelExpr *RHSExpr = Value.getAddrLabelDiffRHS();
1928  llvm::Constant *LHS = tryEmitPrivate(LHSExpr, LHSExpr->getType());
1929  llvm::Constant *RHS = tryEmitPrivate(RHSExpr, RHSExpr->getType());
1930  if (!LHS || !RHS) return nullptr;
1931 
1932  // Compute difference
1933  llvm::Type *ResultType = CGM.getTypes().ConvertType(DestType);
1934  LHS = llvm::ConstantExpr::getPtrToInt(LHS, CGM.IntPtrTy);
1935  RHS = llvm::ConstantExpr::getPtrToInt(RHS, CGM.IntPtrTy);
1936  llvm::Constant *AddrLabelDiff = llvm::ConstantExpr::getSub(LHS, RHS);
1937 
1938  // LLVM is a bit sensitive about the exact format of the
1939  // address-of-label difference; make sure to truncate after
1940  // the subtraction.
1941  return llvm::ConstantExpr::getTruncOrBitCast(AddrLabelDiff, ResultType);
1942  }
1943  case APValue::Struct:
1944  case APValue::Union:
1945  return ConstStructBuilder::BuildStruct(*this, Value, DestType);
1946  case APValue::Array: {
1947  const ConstantArrayType *CAT =
1948  CGM.getContext().getAsConstantArrayType(DestType);
1949  unsigned NumElements = Value.getArraySize();
1950  unsigned NumInitElts = Value.getArrayInitializedElts();
1951 
1952  // Emit array filler, if there is one.
1953  llvm::Constant *Filler = nullptr;
1954  if (Value.hasArrayFiller()) {
1955  Filler = tryEmitAbstractForMemory(Value.getArrayFiller(),
1956  CAT->getElementType());
1957  if (!Filler)
1958  return nullptr;
1959  }
1960 
1961  // Emit initializer elements.
1963  if (Filler && Filler->isNullValue())
1964  Elts.reserve(NumInitElts + 1);
1965  else
1966  Elts.reserve(NumElements);
1967 
1968  llvm::Type *CommonElementType = nullptr;
1969  for (unsigned I = 0; I < NumInitElts; ++I) {
1970  llvm::Constant *C = tryEmitPrivateForMemory(
1971  Value.getArrayInitializedElt(I), CAT->getElementType());
1972  if (!C) return nullptr;
1973 
1974  if (I == 0)
1975  CommonElementType = C->getType();
1976  else if (C->getType() != CommonElementType)
1977  CommonElementType = nullptr;
1978  Elts.push_back(C);
1979  }
1980 
1981  // This means that the array type is probably "IncompleteType" or some
1982  // type that is not ConstantArray.
1983  if (CAT == nullptr && CommonElementType == nullptr && !NumInitElts) {
1984  const ArrayType *AT = CGM.getContext().getAsArrayType(DestType);
1985  CommonElementType = CGM.getTypes().ConvertType(AT->getElementType());
1986  llvm::ArrayType *AType = llvm::ArrayType::get(CommonElementType,
1987  NumElements);
1988  return llvm::ConstantAggregateZero::get(AType);
1989  }
1990 
1991  return EmitArrayConstant(CGM, CAT, CommonElementType, NumElements, Elts,
1992  Filler);
1993  }
1995  return CGM.getCXXABI().EmitMemberPointer(Value, DestType);
1996  }
1997  llvm_unreachable("Unknown APValue kind");
1998 }
1999 
2001  const CompoundLiteralExpr *E) {
2002  return EmittedCompoundLiterals.lookup(E);
2003 }
2004 
2006  const CompoundLiteralExpr *CLE, llvm::GlobalVariable *GV) {
2007  bool Ok = EmittedCompoundLiterals.insert(std::make_pair(CLE, GV)).second;
2008  (void)Ok;
2009  assert(Ok && "CLE has already been emitted!");
2010 }
2011 
2014  assert(E->isFileScope() && "not a file-scope compound literal expr");
2015  return tryEmitGlobalCompoundLiteral(*this, nullptr, E);
2016 }
2017 
2018 llvm::Constant *
2020  // Member pointer constants always have a very particular form.
2021  const MemberPointerType *type = cast<MemberPointerType>(uo->getType());
2022  const ValueDecl *decl = cast<DeclRefExpr>(uo->getSubExpr())->getDecl();
2023 
2024  // A member function pointer.
2025  if (const CXXMethodDecl *method = dyn_cast<CXXMethodDecl>(decl))
2026  return getCXXABI().EmitMemberFunctionPointer(method);
2027 
2028  // Otherwise, a member data pointer.
2029  uint64_t fieldOffset = getContext().getFieldOffset(decl);
2030  CharUnits chars = getContext().toCharUnitsFromBits((int64_t) fieldOffset);
2031  return getCXXABI().EmitMemberDataPointer(type, chars);
2032 }
2033 
2034 static llvm::Constant *EmitNullConstantForBase(CodeGenModule &CGM,
2035  llvm::Type *baseType,
2036  const CXXRecordDecl *base);
2037 
2038 static llvm::Constant *EmitNullConstant(CodeGenModule &CGM,
2039  const RecordDecl *record,
2040  bool asCompleteObject) {
2041  const CGRecordLayout &layout = CGM.getTypes().getCGRecordLayout(record);
2042  llvm::StructType *structure =
2043  (asCompleteObject ? layout.getLLVMType()
2044  : layout.getBaseSubobjectLLVMType());
2045 
2046  unsigned numElements = structure->getNumElements();
2047  std::vector<llvm::Constant *> elements(numElements);
2048 
2049  auto CXXR = dyn_cast<CXXRecordDecl>(record);
2050  // Fill in all the bases.
2051  if (CXXR) {
2052  for (const auto &I : CXXR->bases()) {
2053  if (I.isVirtual()) {
2054  // Ignore virtual bases; if we're laying out for a complete
2055  // object, we'll lay these out later.
2056  continue;
2057  }
2058 
2059  const CXXRecordDecl *base =
2060  cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl());
2061 
2062  // Ignore empty bases.
2063  if (base->isEmpty() ||
2065  .isZero())
2066  continue;
2067 
2068  unsigned fieldIndex = layout.getNonVirtualBaseLLVMFieldNo(base);
2069  llvm::Type *baseType = structure->getElementType(fieldIndex);
2070  elements[fieldIndex] = EmitNullConstantForBase(CGM, baseType, base);
2071  }
2072  }
2073 
2074  // Fill in all the fields.
2075  for (const auto *Field : record->fields()) {
2076  // Fill in non-bitfields. (Bitfields always use a zero pattern, which we
2077  // will fill in later.)
2078  if (!Field->isBitField()) {
2079  unsigned fieldIndex = layout.getLLVMFieldNo(Field);
2080  elements[fieldIndex] = CGM.EmitNullConstant(Field->getType());
2081  }
2082 
2083  // For unions, stop after the first named field.
2084  if (record->isUnion()) {
2085  if (Field->getIdentifier())
2086  break;
2087  if (const auto *FieldRD = Field->getType()->getAsRecordDecl())
2088  if (FieldRD->findFirstNamedDataMember())
2089  break;
2090  }
2091  }
2092 
2093  // Fill in the virtual bases, if we're working with the complete object.
2094  if (CXXR && asCompleteObject) {
2095  for (const auto &I : CXXR->vbases()) {
2096  const CXXRecordDecl *base =
2097  cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl());
2098 
2099  // Ignore empty bases.
2100  if (base->isEmpty())
2101  continue;
2102 
2103  unsigned fieldIndex = layout.getVirtualBaseIndex(base);
2104 
2105  // We might have already laid this field out.
2106  if (elements[fieldIndex]) continue;
2107 
2108  llvm::Type *baseType = structure->getElementType(fieldIndex);
2109  elements[fieldIndex] = EmitNullConstantForBase(CGM, baseType, base);
2110  }
2111  }
2112 
2113  // Now go through all other fields and zero them out.
2114  for (unsigned i = 0; i != numElements; ++i) {
2115  if (!elements[i])
2116  elements[i] = llvm::Constant::getNullValue(structure->getElementType(i));
2117  }
2118 
2119  return llvm::ConstantStruct::get(structure, elements);
2120 }
2121 
2122 /// Emit the null constant for a base subobject.
2123 static llvm::Constant *EmitNullConstantForBase(CodeGenModule &CGM,
2124  llvm::Type *baseType,
2125  const CXXRecordDecl *base) {
2126  const CGRecordLayout &baseLayout = CGM.getTypes().getCGRecordLayout(base);
2127 
2128  // Just zero out bases that don't have any pointer to data members.
2129  if (baseLayout.isZeroInitializableAsBase())
2130  return llvm::Constant::getNullValue(baseType);
2131 
2132  // Otherwise, we can just use its null constant.
2133  return EmitNullConstant(CGM, base, /*asCompleteObject=*/false);
2134 }
2135 
2137  QualType T) {
2138  return emitForMemory(CGM, CGM.EmitNullConstant(T), T);
2139 }
2140 
2142  if (T->getAs<PointerType>())
2143  return getNullPointer(
2144  cast<llvm::PointerType>(getTypes().ConvertTypeForMem(T)), T);
2145 
2146  if (getTypes().isZeroInitializable(T))
2147  return llvm::Constant::getNullValue(getTypes().ConvertTypeForMem(T));
2148 
2149  if (const ConstantArrayType *CAT = Context.getAsConstantArrayType(T)) {
2150  llvm::ArrayType *ATy =
2151  cast<llvm::ArrayType>(getTypes().ConvertTypeForMem(T));
2152 
2153  QualType ElementTy = CAT->getElementType();
2154 
2155  llvm::Constant *Element =
2156  ConstantEmitter::emitNullForMemory(*this, ElementTy);
2157  unsigned NumElements = CAT->getSize().getZExtValue();
2158  SmallVector<llvm::Constant *, 8> Array(NumElements, Element);
2159  return llvm::ConstantArray::get(ATy, Array);
2160  }
2161 
2162  if (const RecordType *RT = T->getAs<RecordType>())
2163  return ::EmitNullConstant(*this, RT->getDecl(), /*complete object*/ true);
2164 
2165  assert(T->isMemberDataPointerType() &&
2166  "Should only see pointers to data members here!");
2167 
2168  return getCXXABI().EmitNullMemberPointer(T->castAs<MemberPointerType>());
2169 }
2170 
2171 llvm::Constant *
2173  return ::EmitNullConstant(*this, Record, false);
2174 }
const llvm::DataLayout & getDataLayout() const
const Expr * getSubExpr() const
Definition: Expr.h:933
const internal::VariadicAllOfMatcher< Type > type
Matches Types in the clang AST.
Defines the clang::ASTContext interface.
CharUnits alignTo(const CharUnits &Align) const
alignTo - Returns the next integer (mod 2**64) that is greater than or equal to this quantity and is ...
Definition: CharUnits.h:183
Expr * getChosenSubExpr() const
getChosenSubExpr - Return the subexpression chosen according to the condition.
Definition: Expr.h:4141
virtual llvm::Constant * EmitMemberPointer(const APValue &MP, QualType MPT)
Create a member pointer for the given member pointer constant.
Definition: CGCXXABI.cpp:112
PointerType - C99 6.7.5.1 - Pointer Declarators.
Definition: Type.h:2554
A (possibly-)qualified type.
Definition: Type.h:643
Static storage duration.
Definition: Specifiers.h:309
bool isArrayType() const
Definition: Type.h:6407
llvm::Constant * emitForInitializer(const APValue &value, LangAS destAddrSpace, QualType destType)
Expr * getArg(unsigned Arg)
getArg - Return the specified argument.
Definition: Expr.h:2675
const Expr * skipRValueSubobjectAdjustments(SmallVectorImpl< const Expr *> &CommaLHS, SmallVectorImpl< SubobjectAdjustment > &Adjustments) const
Walk outwards from an expression we want to bind a reference to and find the expression whose lifetim...
Definition: Expr.cpp:76
ConstStmtVisitor - This class implements a simple visitor for Stmt subclasses.
Definition: StmtVisitor.h:192
__SIZE_TYPE__ size_t
The unsigned integer type of the result of the sizeof operator.
Definition: opencl-c.h:64
CGRecordLayout - This class handles struct and union layout info while lowering AST types to LLVM typ...
bool isMemberDataPointerType() const
Definition: Type.h:6400
llvm::APSInt getValue() const
Definition: FixedPoint.h:110
Expr * getResultExpr()
Return the result expression of this controlling expression.
Definition: Expr.h:5390
llvm::Constant * getMemberPointerConstant(const UnaryOperator *e)
llvm::LLVMContext & getLLVMContext()
const Expr * getInit(unsigned Init) const
Definition: Expr.h:4421
ConstantAddress GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *)
Return a pointer to a constant array for the given ObjCEncodeExpr node.
const ASTRecordLayout & getASTRecordLayout(const RecordDecl *D) const
Get or compute information about the layout of the specified record (struct/union/class) D...
Stmt - This represents one statement.
Definition: Stmt.h:66
llvm::Constant * tryEmitForInitializer(const VarDecl &D)
Try to emit the initiaizer of the given declaration as an abstract constant.
QualType getPointeeType() const
If this is a pointer, ObjC object pointer, or block pointer, this returns the respective pointee...
Definition: Type.cpp:505
CharUnits getBaseClassOffset(const CXXRecordDecl *Base) const
getBaseClassOffset - Get the offset, in chars, for the given base class.
Definition: RecordLayout.h:232
#define trunc(__x)
Definition: tgmath.h:1216
bool isRecordType() const
Definition: Type.h:6431
QualType getQualifiedType(SplitQualType split) const
Un-split a SplitQualType.
Definition: ASTContext.h:1938
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:88
llvm::Constant * emitForMemory(llvm::Constant *C, QualType T)
bool isTransparent() const
Is this a transparent initializer list (that is, an InitListExpr that is purely syntactic, and whose semantics are that of the sole contained initializer)?
Definition: Expr.cpp:2256
ParenExpr - This represents a parethesized expression, e.g.
Definition: Expr.h:1966
Represents an array type, per C99 6.7.5.2 - Array Declarators.
Definition: Type.h:2829
Represents a call to a C++ constructor.
Definition: ExprCXX.h:1326
bool isZero() const
isZero - Test whether the quantity equals zero.
Definition: CharUnits.h:115
const TargetInfo & getTargetInfo() const
Definition: ASTContext.h:693
The l-value was an access to a declared entity or something equivalently strong, like the address of ...
llvm::IntegerType * Int8Ty
i8, i16, i32, and i64
Represents a C++ constructor within a class.
Definition: DeclCXX.h:2561
Represents a prvalue temporary that is written into memory so that a reference can bind to it...
Definition: ExprCXX.h:4320
const AddrLabelExpr * getAddrLabelDiffLHS() const
Definition: APValue.h:490
QualType getElementType() const
Definition: Type.h:2864
bool isDefaultConstructor() const
Whether this constructor is a default constructor (C++ [class.ctor]p5), which can be used to default-...
Definition: DeclCXX.cpp:2433
llvm::Constant * tryEmitPrivateForVarInit(const VarDecl &D)
Represents a variable declaration or definition.
Definition: Decl.h:812
CompoundLiteralExpr - [C99 6.5.2.5].
Definition: Expr.h:3050
const internal::VariadicDynCastAllOfMatcher< Stmt, Expr > expr
Matches expressions.
APFloat & getComplexFloatReal()
Definition: APValue.h:382
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6818
unsigned getCharAlign() const
Definition: TargetInfo.h:381
LangAS
Defines the address space values used by the address space qualifier of QualType. ...
Definition: AddressSpaces.h:25
QualType getTypeInfoType() const
Definition: APValue.cpp:61
llvm::Type * ConvertTypeForMem(QualType T)
ConvertTypeForMem - Convert type T into a llvm::Type.
Expr * getExprOperand() const
Definition: ExprCXX.h:725
Represents an expression – generally a full-expression – that introduces cleanups to be run at the ...
Definition: ExprCXX.h:3207
long i
Definition: xmmintrin.h:1456
bool isZeroInitializableAsBase() const
Check whether this struct can be C++ zero-initialized with a zeroinitializer when considered as a bas...
IdentifierInfo * getIdentifier() const
Get the identifier that names this declaration, if there is one.
Definition: Decl.h:269
Represents a struct/union/class.
Definition: Decl.h:3619
bool isEmpty() const
Determine whether this is an empty class in the sense of (C++11 [meta.unary.prop]).
Definition: DeclCXX.h:1330
Expr * GetTemporaryExpr() const
Retrieve the temporary-generating subexpression whose value will be materialized into a glvalue...
Definition: ExprCXX.h:4361
bool cleanupsHaveSideEffects() const
Definition: ExprCXX.h:3245
CodeGenFunction - This class organizes the per-function state that is used while generating LLVM code...
virtual llvm::Constant * getVTableAddressPointForConstExpr(BaseSubobject Base, const CXXRecordDecl *VTableClass)=0
Get the address point of the vtable for the given base subobject while building a constexpr...
llvm::Type * ConvertType(QualType T)
ConvertType - Convert type T into a llvm::Type.
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:154
llvm::Constant * tryEmitAbstractForInitializer(const VarDecl &D)
Try to emit the initializer of the given declaration as an abstract constant.
bool isFileScope() const
Definition: Expr.h:3080
field_range fields() const
Definition: Decl.h:3810
Represents a member of a struct/union/class.
Definition: Decl.h:2605
StringLiteral * getString()
Definition: ExprObjC.h:62
unsigned getNonVirtualBaseLLVMFieldNo(const CXXRecordDecl *RD) const
bool isReferenceType() const
Definition: Type.h:6363
unsigned getArraySize() const
Definition: APValue.h:446
static CharUnits Zero()
Zero - Construct a CharUnits quantity of zero.
Definition: CharUnits.h:52
Expr * getSubExpr()
Definition: Expr.h:3175
Symbolic representation of typeid(T) for some type T.
Definition: APValue.h:37
i32 captured_struct **param SharedsTy A type which contains references the shared variables *param Shareds Context with the list of shared variables from the p *TaskFunction *param Data Additional data for task generation like final * state
bool isFloat() const
Definition: APValue.h:318
llvm::Constant * GetConstantArrayFromStringLiteral(const StringLiteral *E)
Return a constant array for the given string.
Describes an C or C++ initializer list.
Definition: Expr.h:4373
A C++ typeid expression (C++ [expr.typeid]), which gets the type_info that corresponds to the supplie...
Definition: ExprCXX.h:668
bool isBitField() const
Determines whether this field is a bitfield.
Definition: Decl.h:2683
CharUnits - This is an opaque type for sizes expressed in character units.
Definition: CharUnits.h:37
APValue Val
Val - This is the value the expression can be folded to.
Definition: Expr.h:582
llvm::Constant * tryEmitPrivate(const Expr *E, QualType T)
llvm::StructType * getBaseSubobjectLLVMType() const
Return the "base subobject" LLVM type associated with this record.
Expr * IgnoreParenCasts() LLVM_READONLY
Skip past any parentheses and casts which might surround this expression until reaching a fixed point...
Definition: Expr.cpp:2922
ObjCStringLiteral, used for Objective-C string literals i.e.
Definition: ExprObjC.h:50
field_iterator field_begin() const
Definition: Decl.cpp:4264
unsigned getBitWidthValue(const ASTContext &Ctx) const
Definition: Decl.cpp:3906
bool declaresSameEntity(const Decl *D1, const Decl *D2)
Determine whether two declarations declare the same entity.
Definition: DeclBase.h:1166
bool isInt() const
Definition: APValue.h:317
CastExpr - Base class for type casts, including both implicit casts (ImplicitCastExpr) and explicit c...
Definition: Expr.h:3123
APSInt & getComplexIntReal()
Definition: APValue.h:366
llvm::GlobalValue * getCurrentAddrPrivate()
Get the address of the current location.
virtual llvm::Value * performAddrSpaceCast(CodeGen::CodeGenFunction &CGF, llvm::Value *V, LangAS SrcAddr, LangAS DestAddr, llvm::Type *DestTy, bool IsNonNull=false) const
Perform address space cast of an expression of pointer type.
Definition: TargetInfo.cpp:445
bool isTypeConstant(QualType QTy, bool ExcludeCtorDtor)
isTypeConstant - Determine whether an object of this type can be emitted as a constant.
const Expr * getExpr() const
Get the initialization expression that will be used.
Definition: ExprCXX.h:1211
APValue & getVectorElt(unsigned I)
Definition: APValue.h:410
RecordDecl * getAsRecordDecl() const
Retrieves the RecordDecl this type refers to.
Definition: Type.cpp:1640
static CharUnits One()
One - Construct a CharUnits quantity of one.
Definition: CharUnits.h:57
ConstantAddress getElementBitCast(llvm::Type *ty) const
Definition: Address.h:92
const TargetCodeGenInfo & getTargetCodeGenInfo()
CXXConstructorDecl * getConstructor() const
Get the constructor that this expression will (ultimately) call.
Definition: ExprCXX.h:1398
APValue & getArrayFiller()
Definition: APValue.h:434
bool EvaluateAsLValue(EvalResult &Result, const ASTContext &Ctx, bool InConstantContext=false) const
EvaluateAsLValue - Evaluate an expression to see if we can fold it to an lvalue with link time known ...
llvm::Constant * getNullPointer(llvm::PointerType *T, QualType QT)
Get target specific null pointer.
InitListExpr * getUpdater() const
Definition: Expr.h:4959
QuantityType getQuantity() const
getQuantity - Get the raw integer representation of this quantity.
Definition: CharUnits.h:178
ConstantExpr - An expression that occurs in a constant context and optionally the result of evaluatin...
Definition: Expr.h:948
unsigned Offset
Definition: Format.cpp:1711
ASTRecordLayout - This class contains layout information for one RecordDecl, which is a struct/union/...
Definition: RecordLayout.h:38
bool hasArrayFiller() const
Definition: APValue.h:431
CGObjCRuntime & getObjCRuntime()
Return a reference to the configured Objective-C runtime.
Represent the declaration of a variable (in which case it is an lvalue) a function (in which case it ...
Definition: Decl.h:636
This represents one expression.
Definition: Expr.h:108
bool isCopyOrMoveConstructor(unsigned &TypeQuals) const
Determine whether this is a copy or move constructor.
Definition: DeclCXX.cpp:2453
bool hasLocalStorage() const
Returns true if a variable with function scope is a non-static local variable.
Definition: Decl.h:1035
llvm::Constant * GetAddrOfGlobalVar(const VarDecl *D, llvm::Type *Ty=nullptr, ForDefinition_t IsForDefinition=NotForDefinition)
Return the llvm::Constant for the address of the given global variable.
const T * castAs() const
Member-template castAs<specific type>.
Definition: Type.h:6883
Inits[]
Definition: OpenMPClause.h:150
BlockExpr - Adaptor class for mixing a BlockDecl with expressions.
Definition: Expr.h:5543
const internal::VariadicAllOfMatcher< Decl > decl
Matches declarations.
unsigned getNumInits() const
Definition: Expr.h:4403
field_iterator field_end() const
Definition: Decl.h:3813
CharUnits getTypeAlignInChars(QualType T) const
Return the ABI-specified alignment of a (complete) type T, in characters.
const CXXRecordDecl * getPrimaryBase() const
getPrimaryBase - Get the primary base for this record.
Definition: RecordLayout.h:217
static CharUnits fromQuantity(QuantityType Quantity)
fromQuantity - Construct a CharUnits quantity from a raw integer type.
Definition: CharUnits.h:62
QualType getType() const
Definition: Expr.h:137
llvm::GlobalValue::LinkageTypes getLLVMLinkageVarDefinition(const VarDecl *VD, bool IsConstant)
Returns LLVM linkage for a declarator.
APValue & getStructField(unsigned i)
Definition: APValue.h:463
StorageDuration getStorageDuration() const
Retrieve the storage duration for the materialized temporary.
Definition: ExprCXX.h:4364
QualType getEncodedType() const
Definition: ExprObjC.h:428
ConstantAddress GetAddrOfUuidDescriptor(const CXXUuidofExpr *E)
Get the address of a uuid descriptor .
UnaryOperator - This represents the unary-expression&#39;s (except sizeof and alignof), the postinc/postdec operators from postfix-expression, and various extensions.
Definition: Expr.h:2018
QualType getTypeOperand(ASTContext &Context) const
Retrieves the type operand of this typeid() expression after various required adjustments (removing r...
Definition: ExprCXX.cpp:76
Represents a reference to a non-type template parameter that has been substituted with a template arg...
Definition: ExprCXX.h:4110
APValue * evaluateValue() const
Attempt to evaluate the value of the initializer attached to this declaration, and produce notes expl...
Definition: Decl.cpp:2312
APSInt & getComplexIntImag()
Definition: APValue.h:374
bool isTrivial() const
Whether this function is "trivial" in some specialized C++ senses.
Definition: Decl.h:2040
const Expr * getSubExpr() const
Definition: Expr.h:1982
bool isUnionType() const
Definition: Type.cpp:475
ASTContext & getContext() const
const FieldDecl * getUnionField() const
Definition: APValue.h:474
ConstantAddress GetAddrOfGlobalTemporary(const MaterializeTemporaryExpr *E, const Expr *Inner)
Returns a pointer to a global variable representing a temporary with static or thread storage duratio...
unsigned getBuiltinCallee() const
getBuiltinCallee - If this is a call to a builtin, return the builtin ID of the callee.
Definition: Expr.cpp:1439
The l-value was considered opaque, so the alignment was determined from a type.
RecordDecl * getDecl() const
Definition: Type.h:4433
APValue & getStructBase(unsigned i)
Definition: APValue.h:459
virtual bool useFP16ConversionIntrinsics() const
Check whether llvm intrinsics such as llvm.convert.to.fp16 should be used to convert to and from __fp...
Definition: TargetInfo.h:749
uint64_t getFieldOffset(unsigned FieldNo) const
getFieldOffset - Get the offset of the given field index, in bits.
Definition: RecordLayout.h:190
static ConstantLValue emitConstantObjCStringLiteral(const StringLiteral *S, QualType T, CodeGenModule &CGM)
llvm::Constant * getOrCreateStaticVarDecl(const VarDecl &D, llvm::GlobalValue::LinkageTypes Linkage)
Definition: CGDecl.cpp:215
bool EvaluateAsRValue(EvalResult &Result, const ASTContext &Ctx, bool InConstantContext=false) const
EvaluateAsRValue - Return true if this is a constant which we can fold to an rvalue using any crazy t...
Expr * getBase() const
Definition: Expr.h:4956
APValue & getArrayInitializedElt(unsigned I)
Definition: APValue.h:423
virtual llvm::Value * EmitMemberPointerConversion(CodeGenFunction &CGF, const CastExpr *E, llvm::Value *Src)
Perform a derived-to-base, base-to-derived, or bitcast member pointer conversion. ...
Definition: CGCXXABI.cpp:67
This object has an indeterminate value (C++ [basic.indet]).
Definition: APValue.h:84
#define false
Definition: stdbool.h:17
static QualType getNonMemoryType(CodeGenModule &CGM, QualType type)
bool isExpressibleAsConstantInitializer() const
Definition: ExprObjC.h:151
StringLiteral * getFunctionName()
Definition: Expr.h:1930
Encodes a location in the source.
const AddrLabelExpr * getAddrLabelDiffRHS() const
Definition: APValue.h:494
LangAS getAddressSpace() const
Return the address space of this type.
Definition: Type.h:6243
virtual ConstantAddress GenerateConstantString(const StringLiteral *)=0
Generate a constant string object.
Expr * getSubExpr() const
Definition: Expr.h:2048
ConstantAddress GetAddrOfConstantCFString(const StringLiteral *Literal)
Return a pointer to a constant CFString object for the given string.
CastKind getCastKind() const
Definition: Expr.h:3169
APValue & getUnionValue()
Definition: APValue.h:478
bool isUnnamedBitfield() const
Determines whether this is an unnamed bitfield.
Definition: Decl.h:2686
APFloat & getFloat()
Definition: APValue.h:350
QualType getBaseElementType(const ArrayType *VAT) const
Return the innermost element type of an array type.
Represents a static or instance method of a struct/union/class.
Definition: DeclCXX.h:2109
const ConstantArrayType * getAsConstantArrayType(QualType T) const
Definition: ASTContext.h:2441
ConstantAddress GetAddrOfConstantStringFromLiteral(const StringLiteral *S, StringRef Name=".str")
Return a pointer to a constant array for the given string literal.
StmtVisitor - This class implements a simple visitor for Stmt subclasses.
Definition: StmtVisitor.h:182
llvm::Constant * EmitNullConstantForBase(const CXXRecordDecl *Record)
Return a null constant appropriate for zero-initializing a base class with the given type...
llvm::Constant * GetAddrOfRTTIDescriptor(QualType Ty, bool ForEH=false)
Get the address of the RTTI descriptor for the given type.
const ArrayType * getAsArrayType(QualType T) const
Type Query functions.
llvm::Constant * emitAbstract(const Expr *E, QualType T)
Emit the result of the given expression as an abstract constant, asserting that it succeeded...
ConstantAddress GetWeakRefReference(const ValueDecl *VD)
Get a reference to the target of VD.
void registerCurrentAddrPrivate(llvm::Constant *signal, llvm::GlobalValue *placeholder)
Register a &#39;signal&#39; value with the emitter to inform it where to resolve a placeholder.
llvm::GlobalVariable * getAddrOfConstantCompoundLiteralIfEmitted(const CompoundLiteralExpr *E)
If it&#39;s been emitted already, returns the GlobalVariable corresponding to a compound literal...
bool operator<(DeclarationName LHS, DeclarationName RHS)
Ordering on two declaration names.
Expr * getSubExpr()
Definition: ExprObjC.h:142
ObjCBoxedExpr - used for generalized expression boxing.
Definition: ExprObjC.h:124
void Error(SourceLocation loc, StringRef error)
Emit a general error that something can&#39;t be done.
llvm::Constant * emitNullForMemory(QualType T)
Expr * getArrayFiller()
If this initializer list initializes an array with more elements than there are initializers in the l...
Definition: Expr.h:4467
bool hasFlexibleArrayMember() const
Definition: Decl.h:3673
bool hasSameUnqualifiedType(QualType T1, QualType T2) const
Determine whether the given types are equivalent after cvr-qualifiers have been removed.
Definition: ASTContext.h:2320
SourceLocation getExprLoc() const LLVM_READONLY
getExprLoc - Return the preferred location for the arrow when diagnosing a problem with a generic exp...
Definition: Expr.cpp:215
const Expr * getInitializer() const
Definition: Expr.h:3076
Represents a C11 generic selection.
Definition: Expr.h:5198
AddrLabelExpr - The GNU address of label extension, representing &&label.
Definition: Expr.h:3880
const FieldDecl * getTargetUnionField() const
Definition: Expr.h:3207
This class organizes the cross-function state that is used while generating LLVM code.
bool isTypeOperand() const
Definition: ExprCXX.h:708
Dataflow Directional Tag Classes.
CharUnits getSize() const
getSize - Get the record size in characters.
Definition: RecordLayout.h:183
[C99 6.4.2.2] - A predefined identifier such as func.
Definition: Expr.h:1875
EvalResult is a struct with detailed info about an evaluated expression.
Definition: Expr.h:580
const Expr * getInit() const
Definition: Decl.h:1219
static llvm::Constant * EmitNullConstantForBase(CodeGenModule &CGM, llvm::Type *baseType, const CXXRecordDecl *base)
Emit the null constant for a base subobject.
llvm::Constant * getPointer() const
Definition: Address.h:83
unsigned getArrayInitializedElts() const
Definition: APValue.h:442
llvm::Constant * EmitNullConstant(QualType T)
Return the result of value-initializing the given type, i.e.
A pointer to member type per C++ 8.3.3 - Pointers to members.
Definition: Type.h:2773
llvm::Module & getModule() const
specific_decl_iterator - Iterates over a subrange of declarations stored in a DeclContext, providing only those that are of type SpecificDecl (or a class derived from it).
Definition: DeclBase.h:2041
LabelDecl * getLabel() const
Definition: Expr.h:3902
llvm::Constant * tryEmitPrivateForMemory(const Expr *E, QualType T)
void EmitExplicitCastExprType(const ExplicitCastExpr *E, CodeGenFunction *CGF=nullptr)
Emit type info if type of an expression is a variably modified type.
Definition: CGExpr.cpp:1020
bool HasSideEffects
Whether the evaluated expression has side effects.
Definition: Expr.h:553
A helper class that allows the use of isa/cast/dyncast to detect TagType objects of structs/unions/cl...
Definition: Type.h:4423
StmtVisitorBase - This class implements a simple visitor for Stmt subclasses.
Definition: StmtVisitor.h:35
ObjCEncodeExpr, used for @encode in Objective-C.
Definition: ExprObjC.h:407
const llvm::APInt & getSize() const
Definition: Type.h:2907
uint64_t getCharWidth() const
Return the size of the character type, in bits.
Definition: ASTContext.h:2083
void getObjCEncodingForType(QualType T, std::string &S, const FieldDecl *Field=nullptr, QualType *NotEncodedT=nullptr) const
Emit the Objective-CC type encoding for the given type T into S.
Expr * getArg(unsigned Arg)
Return the specified argument.
Definition: ExprCXX.h:1477
llvm::StructType * getLLVMType() const
Return the "complete object" LLVM type associated with this record.
llvm::Constant * GetAddrOfFunction(GlobalDecl GD, llvm::Type *Ty=nullptr, bool ForVTable=false, bool DontDefer=false, ForDefinition_t IsForDefinition=NotForDefinition)
Return the address of the given function.
Internal linkage, which indicates that the entity can be referred to from within the translation unit...
Definition: Linkage.h:31
ConstantAddress GetAddrOfConstantCompoundLiteral(const CompoundLiteralExpr *E)
Returns a pointer to a constant global variable for the given file-scope compound literal expression...
APValue - This class implements a discriminated union of [uninitialized] [APSInt] [APFloat]...
Definition: APValue.h:76
Represents a base class of a C++ class.
Definition: DeclCXX.h:192
uint64_t getTypeSize(QualType T) const
Return the size of the specified (complete) type T, in bits.
Definition: ASTContext.h:2079
A use of a default initializer in a constructor or in aggregate initialization.
Definition: ExprCXX.h:1183
void setAddrOfConstantCompoundLiteral(const CompoundLiteralExpr *CLE, llvm::GlobalVariable *GV)
Notes that CLE&#39;s GlobalVariable is GV.
static llvm::Constant * EmitNullConstant(CodeGenModule &CGM, const RecordDecl *record, bool asCompleteObject)
CharUnits toCharUnitsFromBits(int64_t BitSize) const
Convert a size in bits to a size in characters.
int64_t toBits(CharUnits CharSize) const
Convert a size in characters to a size in bits.
ValueKind getKind() const
Definition: APValue.h:311
APFloat & getComplexFloatImag()
Definition: APValue.h:390
Represents a C++ struct/union/class.
Definition: DeclCXX.h:300
ChooseExpr - GNU builtin-in function __builtin_choose_expr.
Definition: Expr.h:4100
Qualifiers getQualifiers() const
Retrieve the set of qualifiers applied to this type.
Definition: Type.h:6154
A specialization of Address that requires the address to be an LLVM Constant.
Definition: Address.h:74
There is no such object (it&#39;s outside its lifetime).
Definition: APValue.h:82
CharUnits getNonVirtualSize() const
getNonVirtualSize - Get the non-virtual size (in chars) of an object, which is the size of the object...
Definition: RecordLayout.h:202
unsigned getVirtualBaseIndex(const CXXRecordDecl *base) const
Return the LLVM field index corresponding to the given virtual base.
StringLiteral - This represents a string literal expression, e.g.
Definition: Expr.h:1683
CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
Definition: Expr.h:2518
void finalize(llvm::GlobalVariable *global)
llvm::Constant * tryEmitAbstract(const Expr *E, QualType T)
Try to emit the result of the given expression as an abstract constant.
static ConstantAddress invalid()
Definition: Address.h:79
CGCXXABI & getCXXABI() const
__DEVICE__ int max(int __a, int __b)
result[0]
Definition: emmintrin.h:120
bool isUnion() const
Definition: Decl.h:3278
llvm::Constant * tryEmitAbstractForMemory(const Expr *E, QualType T)
__DEVICE__ int min(int __a, int __b)
FieldDecl * getInitializedFieldInUnion()
If this initializes a union, specifies which field in the union to initialize.
Definition: Expr.h:4485
llvm::Constant * GetAddrOfGlobalBlock(const BlockExpr *BE, StringRef Name)
Gets the address of a block which requires no captures.
Definition: CGBlocks.cpp:1361
QualType getType() const
Definition: Decl.h:647
unsigned getNumArgs() const
Return the number of arguments to the constructor call.
Definition: ExprCXX.h:1474
llvm::BlockAddress * GetAddrOfLabel(const LabelDecl *L)
A Microsoft C++ __uuidof expression, which gets the _GUID that corresponds to the supplied type or ex...
Definition: ExprCXX.h:904
APSInt & getInt()
Definition: APValue.h:336
unsigned getTargetAddressSpace(QualType T) const
Definition: ASTContext.h:2532
const CGRecordLayout & getCGRecordLayout(const RecordDecl *)
getCGRecordLayout - Return record layout info for the given record decl.
const LangOptions & getLangOpts() const
Definition: ASTContext.h:710
Represents the canonical version of C arrays with a specified constant size.
Definition: Type.h:2889
Defines enum values for all the target-independent builtin functions.
Represents an implicitly-generated value initialization of an object of a given type.
Definition: Expr.h:5081
APFixedPoint & getFixedPoint()
Definition: APValue.h:358
CharUnits & getLValueOffset()
Definition: APValue.cpp:717
unsigned getLLVMFieldNo(const FieldDecl *FD) const
Return llvm::StructType element number that corresponds to the field FD.
unsigned getVectorLength() const
Definition: APValue.h:418