clang  3.7.0
CodeGenTypes.cpp
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1 //===--- CodeGenTypes.cpp - Type translation for LLVM CodeGen -------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This is the code that handles AST -> LLVM type lowering.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "CodeGenTypes.h"
15 #include "CGCXXABI.h"
16 #include "CGCall.h"
17 #include "CGOpenCLRuntime.h"
18 #include "CGRecordLayout.h"
19 #include "TargetInfo.h"
20 #include "clang/AST/ASTContext.h"
21 #include "clang/AST/DeclCXX.h"
22 #include "clang/AST/DeclObjC.h"
23 #include "clang/AST/Expr.h"
24 #include "clang/AST/RecordLayout.h"
26 #include "llvm/IR/DataLayout.h"
27 #include "llvm/IR/DerivedTypes.h"
28 #include "llvm/IR/Module.h"
29 using namespace clang;
30 using namespace CodeGen;
31 
33  : CGM(cgm), Context(cgm.getContext()), TheModule(cgm.getModule()),
34  TheDataLayout(cgm.getDataLayout()),
35  Target(cgm.getTarget()), TheCXXABI(cgm.getCXXABI()),
36  TheABIInfo(cgm.getTargetCodeGenInfo().getABIInfo()) {
37  SkippedLayout = false;
38 }
39 
41  llvm::DeleteContainerSeconds(CGRecordLayouts);
42 
43  for (llvm::FoldingSet<CGFunctionInfo>::iterator
44  I = FunctionInfos.begin(), E = FunctionInfos.end(); I != E; )
45  delete &*I++;
46 }
47 
49  llvm::StructType *Ty,
50  StringRef suffix) {
51  SmallString<256> TypeName;
52  llvm::raw_svector_ostream OS(TypeName);
53  OS << RD->getKindName() << '.';
54 
55  // Name the codegen type after the typedef name
56  // if there is no tag type name available
57  if (RD->getIdentifier()) {
58  // FIXME: We should not have to check for a null decl context here.
59  // Right now we do it because the implicit Obj-C decls don't have one.
60  if (RD->getDeclContext())
61  RD->printQualifiedName(OS);
62  else
63  RD->printName(OS);
64  } else if (const TypedefNameDecl *TDD = RD->getTypedefNameForAnonDecl()) {
65  // FIXME: We should not have to check for a null decl context here.
66  // Right now we do it because the implicit Obj-C decls don't have one.
67  if (TDD->getDeclContext())
68  TDD->printQualifiedName(OS);
69  else
70  TDD->printName(OS);
71  } else
72  OS << "anon";
73 
74  if (!suffix.empty())
75  OS << suffix;
76 
77  Ty->setName(OS.str());
78 }
79 
80 /// ConvertTypeForMem - Convert type T into a llvm::Type. This differs from
81 /// ConvertType in that it is used to convert to the memory representation for
82 /// a type. For example, the scalar representation for _Bool is i1, but the
83 /// memory representation is usually i8 or i32, depending on the target.
85  llvm::Type *R = ConvertType(T);
86 
87  // If this is a non-bool type, don't map it.
88  if (!R->isIntegerTy(1))
89  return R;
90 
91  // Otherwise, return an integer of the target-specified size.
92  return llvm::IntegerType::get(getLLVMContext(),
93  (unsigned)Context.getTypeSize(T));
94 }
95 
96 
97 /// isRecordLayoutComplete - Return true if the specified type is already
98 /// completely laid out.
100  llvm::DenseMap<const Type*, llvm::StructType *>::const_iterator I =
101  RecordDeclTypes.find(Ty);
102  return I != RecordDeclTypes.end() && !I->second->isOpaque();
103 }
104 
105 static bool
107  llvm::SmallPtrSet<const RecordDecl*, 16> &AlreadyChecked);
108 
109 
110 /// isSafeToConvert - Return true if it is safe to convert the specified record
111 /// decl to IR and lay it out, false if doing so would cause us to get into a
112 /// recursive compilation mess.
113 static bool
115  llvm::SmallPtrSet<const RecordDecl*, 16> &AlreadyChecked) {
116  // If we have already checked this type (maybe the same type is used by-value
117  // multiple times in multiple structure fields, don't check again.
118  if (!AlreadyChecked.insert(RD).second)
119  return true;
120 
121  const Type *Key = CGT.getContext().getTagDeclType(RD).getTypePtr();
122 
123  // If this type is already laid out, converting it is a noop.
124  if (CGT.isRecordLayoutComplete(Key)) return true;
125 
126  // If this type is currently being laid out, we can't recursively compile it.
127  if (CGT.isRecordBeingLaidOut(Key))
128  return false;
129 
130  // If this type would require laying out bases that are currently being laid
131  // out, don't do it. This includes virtual base classes which get laid out
132  // when a class is translated, even though they aren't embedded by-value into
133  // the class.
134  if (const CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD)) {
135  for (const auto &I : CRD->bases())
136  if (!isSafeToConvert(I.getType()->getAs<RecordType>()->getDecl(),
137  CGT, AlreadyChecked))
138  return false;
139  }
140 
141  // If this type would require laying out members that are currently being laid
142  // out, don't do it.
143  for (const auto *I : RD->fields())
144  if (!isSafeToConvert(I->getType(), CGT, AlreadyChecked))
145  return false;
146 
147  // If there are no problems, lets do it.
148  return true;
149 }
150 
151 /// isSafeToConvert - Return true if it is safe to convert this field type,
152 /// which requires the structure elements contained by-value to all be
153 /// recursively safe to convert.
154 static bool
156  llvm::SmallPtrSet<const RecordDecl*, 16> &AlreadyChecked) {
157  // Strip off atomic type sugar.
158  if (const auto *AT = T->getAs<AtomicType>())
159  T = AT->getValueType();
160 
161  // If this is a record, check it.
162  if (const auto *RT = T->getAs<RecordType>())
163  return isSafeToConvert(RT->getDecl(), CGT, AlreadyChecked);
164 
165  // If this is an array, check the elements, which are embedded inline.
166  if (const auto *AT = CGT.getContext().getAsArrayType(T))
167  return isSafeToConvert(AT->getElementType(), CGT, AlreadyChecked);
168 
169  // Otherwise, there is no concern about transforming this. We only care about
170  // things that are contained by-value in a structure that can have another
171  // structure as a member.
172  return true;
173 }
174 
175 
176 /// isSafeToConvert - Return true if it is safe to convert the specified record
177 /// decl to IR and lay it out, false if doing so would cause us to get into a
178 /// recursive compilation mess.
179 static bool isSafeToConvert(const RecordDecl *RD, CodeGenTypes &CGT) {
180  // If no structs are being laid out, we can certainly do this one.
181  if (CGT.noRecordsBeingLaidOut()) return true;
182 
183  llvm::SmallPtrSet<const RecordDecl*, 16> AlreadyChecked;
184  return isSafeToConvert(RD, CGT, AlreadyChecked);
185 }
186 
187 /// isFuncParamTypeConvertible - Return true if the specified type in a
188 /// function parameter or result position can be converted to an IR type at this
189 /// point. This boils down to being whether it is complete, as well as whether
190 /// we've temporarily deferred expanding the type because we're in a recursive
191 /// context.
193  // Some ABIs cannot have their member pointers represented in IR unless
194  // certain circumstances have been reached.
195  if (const auto *MPT = Ty->getAs<MemberPointerType>())
197 
198  // If this isn't a tagged type, we can convert it!
199  const TagType *TT = Ty->getAs<TagType>();
200  if (!TT) return true;
201 
202  // Incomplete types cannot be converted.
203  if (TT->isIncompleteType())
204  return false;
205 
206  // If this is an enum, then it is always safe to convert.
207  const RecordType *RT = dyn_cast<RecordType>(TT);
208  if (!RT) return true;
209 
210  // Otherwise, we have to be careful. If it is a struct that we're in the
211  // process of expanding, then we can't convert the function type. That's ok
212  // though because we must be in a pointer context under the struct, so we can
213  // just convert it to a dummy type.
214  //
215  // We decide this by checking whether ConvertRecordDeclType returns us an
216  // opaque type for a struct that we know is defined.
217  return isSafeToConvert(RT->getDecl(), *this);
218 }
219 
220 
221 /// Code to verify a given function type is complete, i.e. the return type
222 /// and all of the parameter types are complete. Also check to see if we are in
223 /// a RS_StructPointer context, and if so whether any struct types have been
224 /// pended. If so, we don't want to ask the ABI lowering code to handle a type
225 /// that cannot be converted to an IR type.
228  return false;
229 
230  if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(FT))
231  for (unsigned i = 0, e = FPT->getNumParams(); i != e; i++)
232  if (!isFuncParamTypeConvertible(FPT->getParamType(i)))
233  return false;
234 
235  return true;
236 }
237 
238 /// UpdateCompletedType - When we find the full definition for a TagDecl,
239 /// replace the 'opaque' type we previously made for it if applicable.
241  // If this is an enum being completed, then we flush all non-struct types from
242  // the cache. This allows function types and other things that may be derived
243  // from the enum to be recomputed.
244  if (const EnumDecl *ED = dyn_cast<EnumDecl>(TD)) {
245  // Only flush the cache if we've actually already converted this type.
246  if (TypeCache.count(ED->getTypeForDecl())) {
247  // Okay, we formed some types based on this. We speculated that the enum
248  // would be lowered to i32, so we only need to flush the cache if this
249  // didn't happen.
250  if (!ConvertType(ED->getIntegerType())->isIntegerTy(32))
251  TypeCache.clear();
252  }
253  // If necessary, provide the full definition of a type only used with a
254  // declaration so far.
255  if (CGDebugInfo *DI = CGM.getModuleDebugInfo())
256  DI->completeType(ED);
257  return;
258  }
259 
260  // If we completed a RecordDecl that we previously used and converted to an
261  // anonymous type, then go ahead and complete it now.
262  const RecordDecl *RD = cast<RecordDecl>(TD);
263  if (RD->isDependentType()) return;
264 
265  // Only complete it if we converted it already. If we haven't converted it
266  // yet, we'll just do it lazily.
267  if (RecordDeclTypes.count(Context.getTagDeclType(RD).getTypePtr()))
269 
270  // If necessary, provide the full definition of a type only used with a
271  // declaration so far.
272  if (CGDebugInfo *DI = CGM.getModuleDebugInfo())
273  DI->completeType(RD);
274 }
275 
276 static llvm::Type *getTypeForFormat(llvm::LLVMContext &VMContext,
277  const llvm::fltSemantics &format,
278  bool UseNativeHalf = false) {
279  if (&format == &llvm::APFloat::IEEEhalf) {
280  if (UseNativeHalf)
281  return llvm::Type::getHalfTy(VMContext);
282  else
283  return llvm::Type::getInt16Ty(VMContext);
284  }
285  if (&format == &llvm::APFloat::IEEEsingle)
286  return llvm::Type::getFloatTy(VMContext);
287  if (&format == &llvm::APFloat::IEEEdouble)
288  return llvm::Type::getDoubleTy(VMContext);
289  if (&format == &llvm::APFloat::IEEEquad)
290  return llvm::Type::getFP128Ty(VMContext);
291  if (&format == &llvm::APFloat::PPCDoubleDouble)
292  return llvm::Type::getPPC_FP128Ty(VMContext);
293  if (&format == &llvm::APFloat::x87DoubleExtended)
294  return llvm::Type::getX86_FP80Ty(VMContext);
295  llvm_unreachable("Unknown float format!");
296 }
297 
298 /// ConvertType - Convert the specified type to its LLVM form.
300  T = Context.getCanonicalType(T);
301 
302  const Type *Ty = T.getTypePtr();
303 
304  // RecordTypes are cached and processed specially.
305  if (const RecordType *RT = dyn_cast<RecordType>(Ty))
306  return ConvertRecordDeclType(RT->getDecl());
307 
308  // See if type is already cached.
309  llvm::DenseMap<const Type *, llvm::Type *>::iterator TCI = TypeCache.find(Ty);
310  // If type is found in map then use it. Otherwise, convert type T.
311  if (TCI != TypeCache.end())
312  return TCI->second;
313 
314  // If we don't have it in the cache, convert it now.
315  llvm::Type *ResultType = nullptr;
316  switch (Ty->getTypeClass()) {
317  case Type::Record: // Handled above.
318 #define TYPE(Class, Base)
319 #define ABSTRACT_TYPE(Class, Base)
320 #define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
321 #define DEPENDENT_TYPE(Class, Base) case Type::Class:
322 #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class:
323 #include "clang/AST/TypeNodes.def"
324  llvm_unreachable("Non-canonical or dependent types aren't possible.");
325 
326  case Type::Builtin: {
327  switch (cast<BuiltinType>(Ty)->getKind()) {
328  case BuiltinType::Void:
329  case BuiltinType::ObjCId:
330  case BuiltinType::ObjCClass:
331  case BuiltinType::ObjCSel:
332  // LLVM void type can only be used as the result of a function call. Just
333  // map to the same as char.
334  ResultType = llvm::Type::getInt8Ty(getLLVMContext());
335  break;
336 
337  case BuiltinType::Bool:
338  // Note that we always return bool as i1 for use as a scalar type.
339  ResultType = llvm::Type::getInt1Ty(getLLVMContext());
340  break;
341 
342  case BuiltinType::Char_S:
343  case BuiltinType::Char_U:
344  case BuiltinType::SChar:
345  case BuiltinType::UChar:
346  case BuiltinType::Short:
347  case BuiltinType::UShort:
348  case BuiltinType::Int:
349  case BuiltinType::UInt:
350  case BuiltinType::Long:
351  case BuiltinType::ULong:
352  case BuiltinType::LongLong:
353  case BuiltinType::ULongLong:
354  case BuiltinType::WChar_S:
355  case BuiltinType::WChar_U:
356  case BuiltinType::Char16:
357  case BuiltinType::Char32:
358  ResultType = llvm::IntegerType::get(getLLVMContext(),
359  static_cast<unsigned>(Context.getTypeSize(T)));
360  break;
361 
362  case BuiltinType::Half:
363  // Half FP can either be storage-only (lowered to i16) or native.
364  ResultType =
366  Context.getLangOpts().NativeHalfType ||
367  Context.getLangOpts().HalfArgsAndReturns);
368  break;
369  case BuiltinType::Float:
370  case BuiltinType::Double:
371  case BuiltinType::LongDouble:
372  ResultType = getTypeForFormat(getLLVMContext(),
373  Context.getFloatTypeSemantics(T),
374  /* UseNativeHalf = */ false);
375  break;
376 
377  case BuiltinType::NullPtr:
378  // Model std::nullptr_t as i8*
379  ResultType = llvm::Type::getInt8PtrTy(getLLVMContext());
380  break;
381 
382  case BuiltinType::UInt128:
383  case BuiltinType::Int128:
384  ResultType = llvm::IntegerType::get(getLLVMContext(), 128);
385  break;
386 
387  case BuiltinType::OCLImage1d:
388  case BuiltinType::OCLImage1dArray:
389  case BuiltinType::OCLImage1dBuffer:
390  case BuiltinType::OCLImage2d:
391  case BuiltinType::OCLImage2dArray:
392  case BuiltinType::OCLImage3d:
393  case BuiltinType::OCLSampler:
394  case BuiltinType::OCLEvent:
395  ResultType = CGM.getOpenCLRuntime().convertOpenCLSpecificType(Ty);
396  break;
397 
398  case BuiltinType::Dependent:
399 #define BUILTIN_TYPE(Id, SingletonId)
400 #define PLACEHOLDER_TYPE(Id, SingletonId) \
401  case BuiltinType::Id:
402 #include "clang/AST/BuiltinTypes.def"
403  llvm_unreachable("Unexpected placeholder builtin type!");
404  }
405  break;
406  }
407  case Type::Auto:
408  llvm_unreachable("Unexpected undeduced auto type!");
409  case Type::Complex: {
410  llvm::Type *EltTy = ConvertType(cast<ComplexType>(Ty)->getElementType());
411  ResultType = llvm::StructType::get(EltTy, EltTy, nullptr);
412  break;
413  }
414  case Type::LValueReference:
415  case Type::RValueReference: {
416  const ReferenceType *RTy = cast<ReferenceType>(Ty);
417  QualType ETy = RTy->getPointeeType();
418  llvm::Type *PointeeType = ConvertTypeForMem(ETy);
419  unsigned AS = Context.getTargetAddressSpace(ETy);
420  ResultType = llvm::PointerType::get(PointeeType, AS);
421  break;
422  }
423  case Type::Pointer: {
424  const PointerType *PTy = cast<PointerType>(Ty);
425  QualType ETy = PTy->getPointeeType();
426  llvm::Type *PointeeType = ConvertTypeForMem(ETy);
427  if (PointeeType->isVoidTy())
428  PointeeType = llvm::Type::getInt8Ty(getLLVMContext());
429  unsigned AS = Context.getTargetAddressSpace(ETy);
430  ResultType = llvm::PointerType::get(PointeeType, AS);
431  break;
432  }
433 
434  case Type::VariableArray: {
435  const VariableArrayType *A = cast<VariableArrayType>(Ty);
436  assert(A->getIndexTypeCVRQualifiers() == 0 &&
437  "FIXME: We only handle trivial array types so far!");
438  // VLAs resolve to the innermost element type; this matches
439  // the return of alloca, and there isn't any obviously better choice.
440  ResultType = ConvertTypeForMem(A->getElementType());
441  break;
442  }
443  case Type::IncompleteArray: {
444  const IncompleteArrayType *A = cast<IncompleteArrayType>(Ty);
445  assert(A->getIndexTypeCVRQualifiers() == 0 &&
446  "FIXME: We only handle trivial array types so far!");
447  // int X[] -> [0 x int], unless the element type is not sized. If it is
448  // unsized (e.g. an incomplete struct) just use [0 x i8].
449  ResultType = ConvertTypeForMem(A->getElementType());
450  if (!ResultType->isSized()) {
451  SkippedLayout = true;
452  ResultType = llvm::Type::getInt8Ty(getLLVMContext());
453  }
454  ResultType = llvm::ArrayType::get(ResultType, 0);
455  break;
456  }
457  case Type::ConstantArray: {
458  const ConstantArrayType *A = cast<ConstantArrayType>(Ty);
459  llvm::Type *EltTy = ConvertTypeForMem(A->getElementType());
460 
461  // Lower arrays of undefined struct type to arrays of i8 just to have a
462  // concrete type.
463  if (!EltTy->isSized()) {
464  SkippedLayout = true;
465  EltTy = llvm::Type::getInt8Ty(getLLVMContext());
466  }
467 
468  ResultType = llvm::ArrayType::get(EltTy, A->getSize().getZExtValue());
469  break;
470  }
471  case Type::ExtVector:
472  case Type::Vector: {
473  const VectorType *VT = cast<VectorType>(Ty);
474  ResultType = llvm::VectorType::get(ConvertType(VT->getElementType()),
475  VT->getNumElements());
476  break;
477  }
478  case Type::FunctionNoProto:
479  case Type::FunctionProto: {
480  const FunctionType *FT = cast<FunctionType>(Ty);
481  // First, check whether we can build the full function type. If the
482  // function type depends on an incomplete type (e.g. a struct or enum), we
483  // cannot lower the function type.
484  if (!isFuncTypeConvertible(FT)) {
485  // This function's type depends on an incomplete tag type.
486 
487  // Force conversion of all the relevant record types, to make sure
488  // we re-convert the FunctionType when appropriate.
489  if (const RecordType *RT = FT->getReturnType()->getAs<RecordType>())
490  ConvertRecordDeclType(RT->getDecl());
491  if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(FT))
492  for (unsigned i = 0, e = FPT->getNumParams(); i != e; i++)
493  if (const RecordType *RT = FPT->getParamType(i)->getAs<RecordType>())
494  ConvertRecordDeclType(RT->getDecl());
495 
496  // Return a placeholder type.
497  ResultType = llvm::StructType::get(getLLVMContext());
498 
499  SkippedLayout = true;
500  break;
501  }
502 
503  // While we're converting the parameter types for a function, we don't want
504  // to recursively convert any pointed-to structs. Converting directly-used
505  // structs is ok though.
506  if (!RecordsBeingLaidOut.insert(Ty).second) {
507  ResultType = llvm::StructType::get(getLLVMContext());
508 
509  SkippedLayout = true;
510  break;
511  }
512 
513  // The function type can be built; call the appropriate routines to
514  // build it.
515  const CGFunctionInfo *FI;
516  if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(FT)) {
519  } else {
520  const FunctionNoProtoType *FNPT = cast<FunctionNoProtoType>(FT);
523  }
524 
525  // If there is something higher level prodding our CGFunctionInfo, then
526  // don't recurse into it again.
527  if (FunctionsBeingProcessed.count(FI)) {
528 
529  ResultType = llvm::StructType::get(getLLVMContext());
530  SkippedLayout = true;
531  } else {
532 
533  // Otherwise, we're good to go, go ahead and convert it.
534  ResultType = GetFunctionType(*FI);
535  }
536 
537  RecordsBeingLaidOut.erase(Ty);
538 
539  if (SkippedLayout)
540  TypeCache.clear();
541 
542  if (RecordsBeingLaidOut.empty())
543  while (!DeferredRecords.empty())
544  ConvertRecordDeclType(DeferredRecords.pop_back_val());
545  break;
546  }
547 
548  case Type::ObjCObject:
549  ResultType = ConvertType(cast<ObjCObjectType>(Ty)->getBaseType());
550  break;
551 
552  case Type::ObjCInterface: {
553  // Objective-C interfaces are always opaque (outside of the
554  // runtime, which can do whatever it likes); we never refine
555  // these.
556  llvm::Type *&T = InterfaceTypes[cast<ObjCInterfaceType>(Ty)];
557  if (!T)
559  ResultType = T;
560  break;
561  }
562 
563  case Type::ObjCObjectPointer: {
564  // Protocol qualifications do not influence the LLVM type, we just return a
565  // pointer to the underlying interface type. We don't need to worry about
566  // recursive conversion.
567  llvm::Type *T =
568  ConvertTypeForMem(cast<ObjCObjectPointerType>(Ty)->getPointeeType());
569  ResultType = T->getPointerTo();
570  break;
571  }
572 
573  case Type::Enum: {
574  const EnumDecl *ED = cast<EnumType>(Ty)->getDecl();
575  if (ED->isCompleteDefinition() || ED->isFixed())
576  return ConvertType(ED->getIntegerType());
577  // Return a placeholder 'i32' type. This can be changed later when the
578  // type is defined (see UpdateCompletedType), but is likely to be the
579  // "right" answer.
580  ResultType = llvm::Type::getInt32Ty(getLLVMContext());
581  break;
582  }
583 
584  case Type::BlockPointer: {
585  const QualType FTy = cast<BlockPointerType>(Ty)->getPointeeType();
586  llvm::Type *PointeeType = ConvertTypeForMem(FTy);
587  unsigned AS = Context.getTargetAddressSpace(FTy);
588  ResultType = llvm::PointerType::get(PointeeType, AS);
589  break;
590  }
591 
592  case Type::MemberPointer: {
593  if (!getCXXABI().isMemberPointerConvertible(cast<MemberPointerType>(Ty)))
595  ResultType =
596  getCXXABI().ConvertMemberPointerType(cast<MemberPointerType>(Ty));
597  break;
598  }
599 
600  case Type::Atomic: {
601  QualType valueType = cast<AtomicType>(Ty)->getValueType();
602  ResultType = ConvertTypeForMem(valueType);
603 
604  // Pad out to the inflated size if necessary.
605  uint64_t valueSize = Context.getTypeSize(valueType);
606  uint64_t atomicSize = Context.getTypeSize(Ty);
607  if (valueSize != atomicSize) {
608  assert(valueSize < atomicSize);
609  llvm::Type *elts[] = {
610  ResultType,
611  llvm::ArrayType::get(CGM.Int8Ty, (atomicSize - valueSize) / 8)
612  };
613  ResultType = llvm::StructType::get(getLLVMContext(),
614  llvm::makeArrayRef(elts));
615  }
616  break;
617  }
618  }
619 
620  assert(ResultType && "Didn't convert a type?");
621 
622  TypeCache[Ty] = ResultType;
623  return ResultType;
624 }
625 
627  return isPaddedAtomicType(type->castAs<AtomicType>());
628 }
629 
631  return Context.getTypeSize(type) != Context.getTypeSize(type->getValueType());
632 }
633 
634 /// ConvertRecordDeclType - Lay out a tagged decl type like struct or union.
635 llvm::StructType *CodeGenTypes::ConvertRecordDeclType(const RecordDecl *RD) {
636  // TagDecl's are not necessarily unique, instead use the (clang)
637  // type connected to the decl.
638  const Type *Key = Context.getTagDeclType(RD).getTypePtr();
639 
640  llvm::StructType *&Entry = RecordDeclTypes[Key];
641 
642  // If we don't have a StructType at all yet, create the forward declaration.
643  if (!Entry) {
645  addRecordTypeName(RD, Entry, "");
646  }
647  llvm::StructType *Ty = Entry;
648 
649  // If this is still a forward declaration, or the LLVM type is already
650  // complete, there's nothing more to do.
651  RD = RD->getDefinition();
652  if (!RD || !RD->isCompleteDefinition() || !Ty->isOpaque())
653  return Ty;
654 
655  // If converting this type would cause us to infinitely loop, don't do it!
656  if (!isSafeToConvert(RD, *this)) {
657  DeferredRecords.push_back(RD);
658  return Ty;
659  }
660 
661  // Okay, this is a definition of a type. Compile the implementation now.
662  bool InsertResult = RecordsBeingLaidOut.insert(Key).second;
663  (void)InsertResult;
664  assert(InsertResult && "Recursively compiling a struct?");
665 
666  // Force conversion of non-virtual base classes recursively.
667  if (const CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD)) {
668  for (const auto &I : CRD->bases()) {
669  if (I.isVirtual()) continue;
670 
671  ConvertRecordDeclType(I.getType()->getAs<RecordType>()->getDecl());
672  }
673  }
674 
675  // Layout fields.
676  CGRecordLayout *Layout = ComputeRecordLayout(RD, Ty);
677  CGRecordLayouts[Key] = Layout;
678 
679  // We're done laying out this struct.
680  bool EraseResult = RecordsBeingLaidOut.erase(Key); (void)EraseResult;
681  assert(EraseResult && "struct not in RecordsBeingLaidOut set?");
682 
683  // If this struct blocked a FunctionType conversion, then recompute whatever
684  // was derived from that.
685  // FIXME: This is hugely overconservative.
686  if (SkippedLayout)
687  TypeCache.clear();
688 
689  // If we're done converting the outer-most record, then convert any deferred
690  // structs as well.
691  if (RecordsBeingLaidOut.empty())
692  while (!DeferredRecords.empty())
693  ConvertRecordDeclType(DeferredRecords.pop_back_val());
694 
695  return Ty;
696 }
697 
698 /// getCGRecordLayout - Return record layout info for the given record decl.
699 const CGRecordLayout &
701  const Type *Key = Context.getTagDeclType(RD).getTypePtr();
702 
703  const CGRecordLayout *Layout = CGRecordLayouts.lookup(Key);
704  if (!Layout) {
705  // Compute the type information.
707 
708  // Now try again.
709  Layout = CGRecordLayouts.lookup(Key);
710  }
711 
712  assert(Layout && "Unable to find record layout information for type");
713  return *Layout;
714 }
715 
717  // No need to check for member pointers when not compiling C++.
718  if (!Context.getLangOpts().CPlusPlus)
719  return true;
720 
721  if (const auto *AT = Context.getAsArrayType(T)) {
722  if (isa<IncompleteArrayType>(AT))
723  return true;
724  if (const auto *CAT = dyn_cast<ConstantArrayType>(AT))
725  if (Context.getConstantArrayElementCount(CAT) == 0)
726  return true;
727  T = Context.getBaseElementType(T);
728  }
729 
730  // Records are non-zero-initializable if they contain any
731  // non-zero-initializable subobjects.
732  if (const RecordType *RT = T->getAs<RecordType>()) {
733  const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
734  return isZeroInitializable(RD);
735  }
736 
737  // We have to ask the ABI about member pointers.
738  if (const MemberPointerType *MPT = T->getAs<MemberPointerType>())
739  return getCXXABI().isZeroInitializable(MPT);
740 
741  // Everything else is okay.
742  return true;
743 }
744 
747 }
unsigned getNumElements() const
Definition: Type.h:2724
CGOpenCLRuntime & getOpenCLRuntime()
Return a reference to the configured OpenCL runtime.
Defines the clang::ASTContext interface.
void UpdateCompletedType(const TagDecl *TD)
IdentifierInfo * getIdentifier() const
Definition: Decl.h:163
static llvm::Type * getTypeForFormat(llvm::LLVMContext &VMContext, const llvm::fltSemantics &format, bool UseNativeHalf=false)
bool isFixed() const
Returns true if this is an Objective-C, C++11, or Microsoft-style enumeration with a fixed underlying...
Definition: Decl.h:3177
void addRecordTypeName(const RecordDecl *RD, llvm::StructType *Ty, StringRef suffix)
CGCXXABI & getCXXABI() const
Definition: CodeGenTypes.h:175
ASTContext & getContext() const
Definition: CodeGenTypes.h:172
bool isFuncTypeConvertible(const FunctionType *FT)
llvm::IntegerType * Int8Ty
i8, i16, i32, and i64
const llvm::APInt & getSize() const
Definition: Type.h:2472
CGDebugInfo * getModuleDebugInfo()
uint64_t getTypeSize(QualType T) const
Return the size of the specified (complete) type T, in bits.
Definition: ASTContext.h:1701
llvm::Type * ConvertTypeForMem(QualType T)
const CGFunctionInfo & arrangeFreeFunctionType(CanQual< FunctionProtoType > Ty)
Definition: CGCall.cpp:112
unsigned getIndexTypeCVRQualifiers() const
Definition: Type.h:2441
llvm::Type * ConvertType(QualType T)
ConvertType - Convert type T into a llvm::Type.
bool isCompleteDefinition() const
Definition: Decl.h:2838
bool isPaddedAtomicType(QualType type)
static bool isSafeToConvert(QualType T, CodeGenTypes &CGT, llvm::SmallPtrSet< const RecordDecl *, 16 > &AlreadyChecked)
const LangOptions & getLangOpts() const
Definition: ASTContext.h:533
QualType getReturnType() const
Definition: Type.h:2952
field_range fields() const
Definition: Decl.h:3349
const ArrayType * getAsArrayType(QualType T) const
RecordDecl * getDecl() const
Definition: Type.h:3527
TypeClass getTypeClass() const
Definition: Type.h:1486
bool isIncompleteType(NamedDecl **Def=nullptr) const
Def If non-NULL, and the type refers to some kind of declaration that can be completed (such as a C s...
Definition: Type.cpp:1869
virtual llvm::Type * ConvertMemberPointerType(const MemberPointerType *MPT)
Definition: CGCXXABI.cpp:71
virtual llvm::Type * convertOpenCLSpecificType(const Type *T)
virtual bool isZeroInitializable(const MemberPointerType *MPT)
Definition: CGCXXABI.cpp:147
QualType getValueType() const
Definition: Type.h:4965
ASTContext * Context
virtual bool isMemberPointerConvertible(const MemberPointerType *MPT) const
Return whether or not a member pointers type is convertible to an IR type.
Definition: CGCXXABI.h:163
CodeGenTypes(CodeGenModule &cgm)
DeclContext * getDeclContext()
Definition: DeclBase.h:381
QualType getElementType() const
Definition: Type.h:2723
RecordDecl * getDefinition() const
Definition: Decl.h:3339
TypedefNameDecl * getTypedefNameForAnonDecl() const
Definition: Decl.h:2937
const Type * getTypePtr() const
Definition: Type.h:5016
TagDecl - Represents the declaration of a struct/union/class/enum.
Definition: Decl.h:2694
void printName(raw_ostream &os) const
Definition: Decl.h:185
Represents a canonical, potentially-qualified type.
Definition: CanonicalType.h:52
llvm::LLVMContext & getLLVMContext()
Definition: CodeGenTypes.h:176
const T * castAs() const
Definition: Type.h:5586
bool isDependentType() const
Whether this declaration declares a type that is dependent, i.e., a type that somehow depends on temp...
Definition: Decl.h:2868
void printQualifiedName(raw_ostream &OS) const
Definition: Decl.cpp:1367
QualType getPointeeType() const
Definition: Type.h:2139
bool isRecordBeingLaidOut(const Type *Ty) const
Definition: CodeGenTypes.h:317
Base class for declarations which introduce a typedef-name.
Definition: Decl.h:2576
static const Type * getElementType(const Expr *BaseExpr)
const internal::VariadicAllOfMatcher< Type > type
Matches Types in the clang AST.
Definition: ASTMatchers.h:1639
std::unique_ptr< DiagnosticConsumer > create(StringRef OutputFile, DiagnosticOptions *Diags, bool MergeChildRecords=false)
Returns a DiagnosticConsumer that serializes diagnostics to a bitcode file.
bool isZeroInitializable() const
Check whether this struct can be C++ zero-initialized with a zeroinitializer.
CanQualType getCanonicalType(QualType T) const
Return the canonical (structural) type corresponding to the specified potentially non-canonical type ...
Definition: ASTContext.h:1855
llvm::StructType * ConvertRecordDeclType(const RecordDecl *TD)
ConvertRecordDeclType - Lay out a tagged decl type like struct or union.
const T * getAs() const
Definition: Type.h:5555
QualType getIntegerType() const
Definition: Decl.h:3115
bool isRecordLayoutComplete(const Type *Ty) const
QualType getTagDeclType(const TagDecl *Decl) const
Return the unique reference to the type for the specified TagDecl (struct/union/class/enum) decl...
QualType getPointeeType() const
Definition: Type.h:2286
Defines the C++ Decl subclasses, other than those for templates (found in DeclTemplate.h) and friends (in DeclFriend.h).
Represents a C++ struct/union/class.
Definition: DeclCXX.h:285
bool isFuncParamTypeConvertible(QualType Ty)
static Decl::Kind getKind(const Decl *D)
Definition: DeclBase.cpp:739
unsigned getTargetAddressSpace(QualType T) const
Definition: ASTContext.h:2089
QualType getElementType() const
Definition: Type.h:2434
uint64_t getConstantArrayElementCount(const ConstantArrayType *CA) const
Return number of constant array elements.
CGRecordLayout * ComputeRecordLayout(const RecordDecl *D, llvm::StructType *Ty)
Compute a new LLVM record layout object for the given record.
StringRef getKindName() const
Definition: Decl.h:2893
const llvm::fltSemantics & getFloatTypeSemantics(QualType T) const
Return the APFloat 'semantics' for the specified scalar floating point type.
const CGRecordLayout & getCGRecordLayout(const RecordDecl *)
getCGRecordLayout - Return record layout info for the given record decl.
bool noRecordsBeingLaidOut() const
Definition: CodeGenTypes.h:314
QualType getBaseElementType(const ArrayType *VAT) const
Return the innermost element type of an array type.
bool isZeroInitializable(QualType T)
llvm::FunctionType * GetFunctionType(const CGFunctionInfo &Info)
GetFunctionType - Get the LLVM function type for.
Definition: CGCall.cpp:1253