Coverage Report

Created: 2022-01-22 13:19

/Users/buildslave/jenkins/workspace/coverage/llvm-project/clang/lib/CodeGen/CGExprAgg.cpp
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Count
Source (jump to first uncovered line)
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//===--- CGExprAgg.cpp - Emit LLVM Code from Aggregate 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 Aggregate Expr nodes as LLVM code.
10
//
11
//===----------------------------------------------------------------------===//
12
13
#include "CGCXXABI.h"
14
#include "CGObjCRuntime.h"
15
#include "CodeGenFunction.h"
16
#include "CodeGenModule.h"
17
#include "ConstantEmitter.h"
18
#include "TargetInfo.h"
19
#include "clang/AST/ASTContext.h"
20
#include "clang/AST/Attr.h"
21
#include "clang/AST/DeclCXX.h"
22
#include "clang/AST/DeclTemplate.h"
23
#include "clang/AST/StmtVisitor.h"
24
#include "llvm/IR/Constants.h"
25
#include "llvm/IR/Function.h"
26
#include "llvm/IR/GlobalVariable.h"
27
#include "llvm/IR/IntrinsicInst.h"
28
#include "llvm/IR/Intrinsics.h"
29
using namespace clang;
30
using namespace CodeGen;
31
32
//===----------------------------------------------------------------------===//
33
//                        Aggregate Expression Emitter
34
//===----------------------------------------------------------------------===//
35
36
namespace  {
37
class AggExprEmitter : public StmtVisitor<AggExprEmitter> {
38
  CodeGenFunction &CGF;
39
  CGBuilderTy &Builder;
40
  AggValueSlot Dest;
41
  bool IsResultUnused;
42
43
71.9k
  AggValueSlot EnsureSlot(QualType T) {
44
71.9k
    if (!Dest.isIgnored()) 
return Dest71.8k
;
45
73
    return CGF.CreateAggTemp(T, "agg.tmp.ensured");
46
71.9k
  }
47
7.52k
  void EnsureDest(QualType T) {
48
7.52k
    if (!Dest.isIgnored()) 
return7.35k
;
49
161
    Dest = CGF.CreateAggTemp(T, "agg.tmp.ensured");
50
161
  }
51
52
  // Calls `Fn` with a valid return value slot, potentially creating a temporary
53
  // to do so. If a temporary is created, an appropriate copy into `Dest` will
54
  // be emitted, as will lifetime markers.
55
  //
56
  // The given function should take a ReturnValueSlot, and return an RValue that
57
  // points to said slot.
58
  void withReturnValueSlot(const Expr *E,
59
                           llvm::function_ref<RValue(ReturnValueSlot)> Fn);
60
61
public:
62
  AggExprEmitter(CodeGenFunction &cgf, AggValueSlot Dest, bool IsResultUnused)
63
    : CGF(cgf), Builder(CGF.Builder), Dest(Dest),
64
83.6k
    IsResultUnused(IsResultUnused) { }
65
66
  //===--------------------------------------------------------------------===//
67
  //                               Utilities
68
  //===--------------------------------------------------------------------===//
69
70
  /// EmitAggLoadOfLValue - Given an expression with aggregate type that
71
  /// represents a value lvalue, this method emits the address of the lvalue,
72
  /// then loads the result into DestPtr.
73
  void EmitAggLoadOfLValue(const Expr *E);
74
75
  enum ExprValueKind {
76
    EVK_RValue,
77
    EVK_NonRValue
78
  };
79
80
  /// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
81
  /// SrcIsRValue is true if source comes from an RValue.
82
  void EmitFinalDestCopy(QualType type, const LValue &src,
83
                         ExprValueKind SrcValueKind = EVK_NonRValue);
84
  void EmitFinalDestCopy(QualType type, RValue src);
85
  void EmitCopy(QualType type, const AggValueSlot &dest,
86
                const AggValueSlot &src);
87
88
  void EmitMoveFromReturnSlot(const Expr *E, RValue Src);
89
90
  void EmitArrayInit(Address DestPtr, llvm::ArrayType *AType,
91
                     QualType ArrayQTy, InitListExpr *E);
92
93
3.53k
  AggValueSlot::NeedsGCBarriers_t needsGC(QualType T) {
94
3.53k
    if (CGF.getLangOpts().getGC() && 
TypeRequiresGCollection(T)24
)
95
20
      return AggValueSlot::NeedsGCBarriers;
96
3.51k
    return AggValueSlot::DoesNotNeedGCBarriers;
97
3.53k
  }
98
99
  bool TypeRequiresGCollection(QualType T);
100
101
  //===--------------------------------------------------------------------===//
102
  //                            Visitor Methods
103
  //===--------------------------------------------------------------------===//
104
105
126k
  void Visit(Expr *E) {
106
126k
    ApplyDebugLocation DL(CGF, E);
107
126k
    StmtVisitor<AggExprEmitter>::Visit(E);
108
126k
  }
109
110
0
  void VisitStmt(Stmt *S) {
111
0
    CGF.ErrorUnsupported(S, "aggregate expression");
112
0
  }
113
102
  void VisitParenExpr(ParenExpr *PE) { Visit(PE->getSubExpr()); }
114
0
  void VisitGenericSelectionExpr(GenericSelectionExpr *GE) {
115
0
    Visit(GE->getResultExpr());
116
0
  }
117
10
  void VisitCoawaitExpr(CoawaitExpr *E) {
118
10
    CGF.EmitCoawaitExpr(*E, Dest, IsResultUnused);
119
10
  }
120
0
  void VisitCoyieldExpr(CoyieldExpr *E) {
121
0
    CGF.EmitCoyieldExpr(*E, Dest, IsResultUnused);
122
0
  }
123
0
  void VisitUnaryCoawait(UnaryOperator *E) { Visit(E->getSubExpr()); }
124
639
  void VisitUnaryExtension(UnaryOperator *E) { Visit(E->getSubExpr()); }
125
0
  void VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *E) {
126
0
    return Visit(E->getReplacement());
127
0
  }
128
129
6
  void VisitConstantExpr(ConstantExpr *E) {
130
6
    EnsureDest(E->getType());
131
132
6
    if (llvm::Value *Result = ConstantEmitter(CGF).tryEmitConstantExpr(E)) {
133
5
      CGF.EmitAggregateStore(Result, Dest.getAddress(),
134
5
                             E->getType().isVolatileQualified());
135
5
      return;
136
5
    }
137
1
    return Visit(E->getSubExpr());
138
6
  }
139
140
  // l-values.
141
2.44k
  void VisitDeclRefExpr(DeclRefExpr *E) { EmitAggLoadOfLValue(E); }
142
7
  void VisitMemberExpr(MemberExpr *ME) { EmitAggLoadOfLValue(ME); }
143
98
  void VisitUnaryDeref(UnaryOperator *E) { EmitAggLoadOfLValue(E); }
144
23
  void VisitStringLiteral(StringLiteral *E) { EmitAggLoadOfLValue(E); }
145
  void VisitCompoundLiteralExpr(CompoundLiteralExpr *E);
146
6
  void VisitArraySubscriptExpr(ArraySubscriptExpr *E) {
147
6
    EmitAggLoadOfLValue(E);
148
6
  }
149
0
  void VisitPredefinedExpr(const PredefinedExpr *E) {
150
0
    EmitAggLoadOfLValue(E);
151
0
  }
152
153
  // Operators.
154
  void VisitCastExpr(CastExpr *E);
155
  void VisitCallExpr(const CallExpr *E);
156
  void VisitStmtExpr(const StmtExpr *E);
157
  void VisitBinaryOperator(const BinaryOperator *BO);
158
  void VisitPointerToDataMemberBinaryOperator(const BinaryOperator *BO);
159
  void VisitBinAssign(const BinaryOperator *E);
160
  void VisitBinComma(const BinaryOperator *E);
161
  void VisitBinCmp(const BinaryOperator *E);
162
0
  void VisitCXXRewrittenBinaryOperator(CXXRewrittenBinaryOperator *E) {
163
0
    Visit(E->getSemanticForm());
164
0
  }
165
166
  void VisitObjCMessageExpr(ObjCMessageExpr *E);
167
5
  void VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
168
5
    EmitAggLoadOfLValue(E);
169
5
  }
170
171
  void VisitDesignatedInitUpdateExpr(DesignatedInitUpdateExpr *E);
172
  void VisitAbstractConditionalOperator(const AbstractConditionalOperator *CO);
173
  void VisitChooseExpr(const ChooseExpr *CE);
174
  void VisitInitListExpr(InitListExpr *E);
175
  void VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E,
176
                              llvm::Value *outerBegin = nullptr);
177
  void VisitImplicitValueInitExpr(ImplicitValueInitExpr *E);
178
0
  void VisitNoInitExpr(NoInitExpr *E) { } // Do nothing.
179
383
  void VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
180
383
    CodeGenFunction::CXXDefaultArgExprScope Scope(CGF, DAE);
181
383
    Visit(DAE->getExpr());
182
383
  }
183
57
  void VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) {
184
57
    CodeGenFunction::CXXDefaultInitExprScope Scope(CGF, DIE);
185
57
    Visit(DIE->getExpr());
186
57
  }
187
  void VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E);
188
  void VisitCXXConstructExpr(const CXXConstructExpr *E);
189
  void VisitCXXInheritedCtorInitExpr(const CXXInheritedCtorInitExpr *E);
190
  void VisitLambdaExpr(LambdaExpr *E);
191
  void VisitCXXStdInitializerListExpr(CXXStdInitializerListExpr *E);
192
  void VisitExprWithCleanups(ExprWithCleanups *E);
193
  void VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E);
194
0
  void VisitCXXTypeidExpr(CXXTypeidExpr *E) { EmitAggLoadOfLValue(E); }
195
  void VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E);
196
  void VisitOpaqueValueExpr(OpaqueValueExpr *E);
197
198
56
  void VisitPseudoObjectExpr(PseudoObjectExpr *E) {
199
56
    if (E->isGLValue()) {
200
0
      LValue LV = CGF.EmitPseudoObjectLValue(E);
201
0
      return EmitFinalDestCopy(E->getType(), LV);
202
0
    }
203
204
56
    CGF.EmitPseudoObjectRValue(E, EnsureSlot(E->getType()));
205
56
  }
206
207
  void VisitVAArgExpr(VAArgExpr *E);
208
209
  void EmitInitializationToLValue(Expr *E, LValue Address);
210
  void EmitNullInitializationToLValue(LValue Address);
211
  //  case Expr::ChooseExprClass:
212
1
  void VisitCXXThrowExpr(const CXXThrowExpr *E) { CGF.EmitCXXThrowExpr(E); }
213
15
  void VisitAtomicExpr(AtomicExpr *E) {
214
15
    RValue Res = CGF.EmitAtomicExpr(E);
215
15
    EmitFinalDestCopy(E->getType(), Res);
216
15
  }
217
};
218
}  // end anonymous namespace.
219
220
//===----------------------------------------------------------------------===//
221
//                                Utilities
222
//===----------------------------------------------------------------------===//
223
224
/// EmitAggLoadOfLValue - Given an expression with aggregate type that
225
/// represents a value lvalue, this method emits the address of the lvalue,
226
/// then loads the result into DestPtr.
227
2.60k
void AggExprEmitter::EmitAggLoadOfLValue(const Expr *E) {
228
2.60k
  LValue LV = CGF.EmitLValue(E);
229
230
  // If the type of the l-value is atomic, then do an atomic load.
231
2.60k
  if (LV.getType()->isAtomicType() || 
CGF.LValueIsSuitableForInlineAtomic(LV)2.59k
) {
232
13
    CGF.EmitAtomicLoad(LV, E->getExprLoc(), Dest);
233
13
    return;
234
13
  }
235
236
2.59k
  EmitFinalDestCopy(E->getType(), LV);
237
2.59k
}
238
239
/// True if the given aggregate type requires special GC API calls.
240
24
bool AggExprEmitter::TypeRequiresGCollection(QualType T) {
241
  // Only record types have members that might require garbage collection.
242
24
  const RecordType *RecordTy = T->getAs<RecordType>();
243
24
  if (!RecordTy) 
return false0
;
244
245
  // Don't mess with non-trivial C++ types.
246
24
  RecordDecl *Record = RecordTy->getDecl();
247
24
  if (isa<CXXRecordDecl>(Record) &&
248
24
      
(5
cast<CXXRecordDecl>(Record)->hasNonTrivialCopyConstructor()5
||
249
5
       !cast<CXXRecordDecl>(Record)->hasTrivialDestructor()))
250
0
    return false;
251
252
  // Check whether the type has an object member.
253
24
  return Record->hasObjectMember();
254
24
}
255
256
void AggExprEmitter::withReturnValueSlot(
257
7.58k
    const Expr *E, llvm::function_ref<RValue(ReturnValueSlot)> EmitCall) {
258
7.58k
  QualType RetTy = E->getType();
259
7.58k
  bool RequiresDestruction =
260
7.58k
      !Dest.isExternallyDestructed() &&
261
7.58k
      
RetTy.isDestructedType() == QualType::DK_nontrivial_c_struct2.25k
;
262
263
  // If it makes no observable difference, save a memcpy + temporary.
264
  //
265
  // We need to always provide our own temporary if destruction is required.
266
  // Otherwise, EmitCall will emit its own, notice that it's "unused", and end
267
  // its lifetime before we have the chance to emit a proper destructor call.
268
7.58k
  bool UseTemp = Dest.isPotentiallyAliased() || 
Dest.requiresGCollection()7.40k
||
269
7.58k
                 
(7.40k
RequiresDestruction7.40k
&&
!Dest.getAddress().isValid()12
);
270
271
7.58k
  Address RetAddr = Address::invalid();
272
7.58k
  Address RetAllocaAddr = Address::invalid();
273
274
7.58k
  EHScopeStack::stable_iterator LifetimeEndBlock;
275
7.58k
  llvm::Value *LifetimeSizePtr = nullptr;
276
7.58k
  llvm::IntrinsicInst *LifetimeStartInst = nullptr;
277
7.58k
  if (!UseTemp) {
278
7.39k
    RetAddr = Dest.getAddress();
279
7.39k
  } else {
280
190
    RetAddr = CGF.CreateMemTemp(RetTy, "tmp", &RetAllocaAddr);
281
190
    llvm::TypeSize Size =
282
190
        CGF.CGM.getDataLayout().getTypeAllocSize(CGF.ConvertTypeForMem(RetTy));
283
190
    LifetimeSizePtr = CGF.EmitLifetimeStart(Size, RetAllocaAddr.getPointer());
284
190
    if (LifetimeSizePtr) {
285
7
      LifetimeStartInst =
286
7
          cast<llvm::IntrinsicInst>(std::prev(Builder.GetInsertPoint()));
287
7
      assert(LifetimeStartInst->getIntrinsicID() ==
288
7
                 llvm::Intrinsic::lifetime_start &&
289
7
             "Last insertion wasn't a lifetime.start?");
290
291
0
      CGF.pushFullExprCleanup<CodeGenFunction::CallLifetimeEnd>(
292
7
          NormalEHLifetimeMarker, RetAllocaAddr, LifetimeSizePtr);
293
7
      LifetimeEndBlock = CGF.EHStack.stable_begin();
294
7
    }
295
190
  }
296
297
0
  RValue Src =
298
7.58k
      EmitCall(ReturnValueSlot(RetAddr, Dest.isVolatile(), IsResultUnused,
299
7.58k
                               Dest.isExternallyDestructed()));
300
301
7.58k
  if (!UseTemp)
302
7.39k
    return;
303
304
190
  assert(Dest.isIgnored() || Dest.getPointer() != Src.getAggregatePointer());
305
0
  EmitFinalDestCopy(E->getType(), Src);
306
307
190
  if (!RequiresDestruction && 
LifetimeStartInst178
) {
308
    // If there's no dtor to run, the copy was the last use of our temporary.
309
    // Since we're not guaranteed to be in an ExprWithCleanups, clean up
310
    // eagerly.
311
5
    CGF.DeactivateCleanupBlock(LifetimeEndBlock, LifetimeStartInst);
312
5
    CGF.EmitLifetimeEnd(LifetimeSizePtr, RetAllocaAddr.getPointer());
313
5
  }
314
190
}
315
316
/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
317
209
void AggExprEmitter::EmitFinalDestCopy(QualType type, RValue src) {
318
209
  assert(src.isAggregate() && "value must be aggregate value!");
319
0
  LValue srcLV = CGF.MakeAddrLValue(src.getAggregateAddress(), type);
320
209
  EmitFinalDestCopy(type, srcLV, EVK_RValue);
321
209
}
322
323
/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
324
void AggExprEmitter::EmitFinalDestCopy(QualType type, const LValue &src,
325
3.64k
                                       ExprValueKind SrcValueKind) {
326
  // If Dest is ignored, then we're evaluating an aggregate expression
327
  // in a context that doesn't care about the result.  Note that loads
328
  // from volatile l-values force the existence of a non-ignored
329
  // destination.
330
3.64k
  if (Dest.isIgnored())
331
481
    return;
332
333
  // Copy non-trivial C structs here.
334
3.16k
  LValue DstLV = CGF.MakeAddrLValue(
335
3.16k
      Dest.getAddress(), Dest.isVolatile() ? 
type.withVolatile()25
:
type3.14k
);
336
337
3.16k
  if (SrcValueKind == EVK_RValue) {
338
197
    if (type.isNonTrivialToPrimitiveDestructiveMove() == QualType::PCK_Struct) {
339
8
      if (Dest.isPotentiallyAliased())
340
8
        CGF.callCStructMoveAssignmentOperator(DstLV, src);
341
0
      else
342
0
        CGF.callCStructMoveConstructor(DstLV, src);
343
8
      return;
344
8
    }
345
2.97k
  } else {
346
2.97k
    if (type.isNonTrivialToPrimitiveCopy() == QualType::PCK_Struct) {
347
77
      if (Dest.isPotentiallyAliased())
348
22
        CGF.callCStructCopyAssignmentOperator(DstLV, src);
349
55
      else
350
55
        CGF.callCStructCopyConstructor(DstLV, src);
351
77
      return;
352
77
    }
353
2.97k
  }
354
355
3.08k
  AggValueSlot srcAgg = AggValueSlot::forLValue(
356
3.08k
      src, CGF, AggValueSlot::IsDestructed, needsGC(type),
357
3.08k
      AggValueSlot::IsAliased, AggValueSlot::MayOverlap);
358
3.08k
  EmitCopy(type, Dest, srcAgg);
359
3.08k
}
360
361
/// Perform a copy from the source into the destination.
362
///
363
/// \param type - the type of the aggregate being copied; qualifiers are
364
///   ignored
365
void AggExprEmitter::EmitCopy(QualType type, const AggValueSlot &dest,
366
3.08k
                              const AggValueSlot &src) {
367
3.08k
  if (dest.requiresGCollection()) {
368
6
    CharUnits sz = dest.getPreferredSize(CGF.getContext(), type);
369
6
    llvm::Value *size = llvm::ConstantInt::get(CGF.SizeTy, sz.getQuantity());
370
6
    CGF.CGM.getObjCRuntime().EmitGCMemmoveCollectable(CGF,
371
6
                                                      dest.getAddress(),
372
6
                                                      src.getAddress(),
373
6
                                                      size);
374
6
    return;
375
6
  }
376
377
  // If the result of the assignment is used, copy the LHS there also.
378
  // It's volatile if either side is.  Use the minimum alignment of
379
  // the two sides.
380
3.07k
  LValue DestLV = CGF.MakeAddrLValue(dest.getAddress(), type);
381
3.07k
  LValue SrcLV = CGF.MakeAddrLValue(src.getAddress(), type);
382
3.07k
  CGF.EmitAggregateCopy(DestLV, SrcLV, type, dest.mayOverlap(),
383
3.07k
                        dest.isVolatile() || 
src.isVolatile()3.06k
);
384
3.07k
}
385
386
/// Emit the initializer for a std::initializer_list initialized with a
387
/// real initializer list.
388
void
389
186
AggExprEmitter::VisitCXXStdInitializerListExpr(CXXStdInitializerListExpr *E) {
390
  // Emit an array containing the elements.  The array is externally destructed
391
  // if the std::initializer_list object is.
392
186
  ASTContext &Ctx = CGF.getContext();
393
186
  LValue Array = CGF.EmitLValue(E->getSubExpr());
394
186
  assert(Array.isSimple() && "initializer_list array not a simple lvalue");
395
0
  Address ArrayPtr = Array.getAddress(CGF);
396
397
186
  const ConstantArrayType *ArrayType =
398
186
      Ctx.getAsConstantArrayType(E->getSubExpr()->getType());
399
186
  assert(ArrayType && "std::initializer_list constructed from non-array");
400
401
  // FIXME: Perform the checks on the field types in SemaInit.
402
0
  RecordDecl *Record = E->getType()->castAs<RecordType>()->getDecl();
403
186
  RecordDecl::field_iterator Field = Record->field_begin();
404
186
  if (Field == Record->field_end()) {
405
1
    CGF.ErrorUnsupported(E, "weird std::initializer_list");
406
1
    return;
407
1
  }
408
409
  // Start pointer.
410
185
  if (!Field->getType()->isPointerType() ||
411
185
      !Ctx.hasSameType(Field->getType()->getPointeeType(),
412
185
                       ArrayType->getElementType())) {
413
0
    CGF.ErrorUnsupported(E, "weird std::initializer_list");
414
0
    return;
415
0
  }
416
417
185
  AggValueSlot Dest = EnsureSlot(E->getType());
418
185
  LValue DestLV = CGF.MakeAddrLValue(Dest.getAddress(), E->getType());
419
185
  LValue Start = CGF.EmitLValueForFieldInitialization(DestLV, *Field);
420
185
  llvm::Value *Zero = llvm::ConstantInt::get(CGF.PtrDiffTy, 0);
421
185
  llvm::Value *IdxStart[] = { Zero, Zero };
422
185
  llvm::Value *ArrayStart = Builder.CreateInBoundsGEP(
423
185
      ArrayPtr.getElementType(), ArrayPtr.getPointer(), IdxStart, "arraystart");
424
185
  CGF.EmitStoreThroughLValue(RValue::get(ArrayStart), Start);
425
185
  ++Field;
426
427
185
  if (Field == Record->field_end()) {
428
0
    CGF.ErrorUnsupported(E, "weird std::initializer_list");
429
0
    return;
430
0
  }
431
432
185
  llvm::Value *Size = Builder.getInt(ArrayType->getSize());
433
185
  LValue EndOrLength = CGF.EmitLValueForFieldInitialization(DestLV, *Field);
434
185
  if (Field->getType()->isPointerType() &&
435
185
      Ctx.hasSameType(Field->getType()->getPointeeType(),
436
7
                      ArrayType->getElementType())) {
437
    // End pointer.
438
7
    llvm::Value *IdxEnd[] = { Zero, Size };
439
7
    llvm::Value *ArrayEnd = Builder.CreateInBoundsGEP(
440
7
        ArrayPtr.getElementType(), ArrayPtr.getPointer(), IdxEnd, "arrayend");
441
7
    CGF.EmitStoreThroughLValue(RValue::get(ArrayEnd), EndOrLength);
442
178
  } else if (Ctx.hasSameType(Field->getType(), Ctx.getSizeType())) {
443
    // Length.
444
178
    CGF.EmitStoreThroughLValue(RValue::get(Size), EndOrLength);
445
178
  } else {
446
0
    CGF.ErrorUnsupported(E, "weird std::initializer_list");
447
0
    return;
448
0
  }
449
185
}
450
451
/// Determine if E is a trivial array filler, that is, one that is
452
/// equivalent to zero-initialization.
453
1.63k
static bool isTrivialFiller(Expr *E) {
454
1.63k
  if (!E)
455
1.55k
    return true;
456
457
76
  if (isa<ImplicitValueInitExpr>(E))
458
42
    return true;
459
460
34
  if (auto *ILE = dyn_cast<InitListExpr>(E)) {
461
6
    if (ILE->getNumInits())
462
5
      return false;
463
1
    return isTrivialFiller(ILE->getArrayFiller());
464
6
  }
465
466
28
  if (auto *Cons = dyn_cast_or_null<CXXConstructExpr>(E))
467
25
    return Cons->getConstructor()->isDefaultConstructor() &&
468
25
           
Cons->getConstructor()->isTrivial()23
;
469
470
  // FIXME: Are there other cases where we can avoid emitting an initializer?
471
3
  return false;
472
28
}
473
474
/// Emit initialization of an array from an initializer list.
475
void AggExprEmitter::EmitArrayInit(Address DestPtr, llvm::ArrayType *AType,
476
1.66k
                                   QualType ArrayQTy, InitListExpr *E) {
477
1.66k
  uint64_t NumInitElements = E->getNumInits();
478
479
1.66k
  uint64_t NumArrayElements = AType->getNumElements();
480
1.66k
  assert(NumInitElements <= NumArrayElements);
481
482
0
  QualType elementType =
483
1.66k
      CGF.getContext().getAsArrayType(ArrayQTy)->getElementType();
484
485
  // DestPtr is an array*.  Construct an elementType* by drilling
486
  // down a level.
487
1.66k
  llvm::Value *zero = llvm::ConstantInt::get(CGF.SizeTy, 0);
488
1.66k
  llvm::Value *indices[] = { zero, zero };
489
1.66k
  llvm::Value *begin = Builder.CreateInBoundsGEP(
490
1.66k
      DestPtr.getElementType(), DestPtr.getPointer(), indices,
491
1.66k
      "arrayinit.begin");
492
493
1.66k
  CharUnits elementSize = CGF.getContext().getTypeSizeInChars(elementType);
494
1.66k
  CharUnits elementAlign =
495
1.66k
    DestPtr.getAlignment().alignmentOfArrayElement(elementSize);
496
1.66k
  llvm::Type *llvmElementType = CGF.ConvertTypeForMem(elementType);
497
498
  // Consider initializing the array by copying from a global. For this to be
499
  // more efficient than per-element initialization, the size of the elements
500
  // with explicit initializers should be large enough.
501
1.66k
  if (NumInitElements * elementSize.getQuantity() > 16 &&
502
1.66k
      
elementType.isTriviallyCopyableType(CGF.getContext())130
) {
503
87
    CodeGen::CodeGenModule &CGM = CGF.CGM;
504
87
    ConstantEmitter Emitter(CGF);
505
87
    LangAS AS = ArrayQTy.getAddressSpace();
506
87
    if (llvm::Constant *C = Emitter.tryEmitForInitializer(E, AS, ArrayQTy)) {
507
33
      auto GV = new llvm::GlobalVariable(
508
33
          CGM.getModule(), C->getType(),
509
33
          CGM.isTypeConstant(ArrayQTy, /* ExcludeCtorDtor= */ true),
510
33
          llvm::GlobalValue::PrivateLinkage, C, "constinit",
511
33
          /* InsertBefore= */ nullptr, llvm::GlobalVariable::NotThreadLocal,
512
33
          CGM.getContext().getTargetAddressSpace(AS));
513
33
      Emitter.finalize(GV);
514
33
      CharUnits Align = CGM.getContext().getTypeAlignInChars(ArrayQTy);
515
33
      GV->setAlignment(Align.getAsAlign());
516
33
      Address GVAddr(GV, GV->getValueType(), Align);
517
33
      EmitFinalDestCopy(ArrayQTy, CGF.MakeAddrLValue(GVAddr, ArrayQTy));
518
33
      return;
519
33
    }
520
87
  }
521
522
  // Exception safety requires us to destroy all the
523
  // already-constructed members if an initializer throws.
524
  // For that, we'll need an EH cleanup.
525
1.63k
  QualType::DestructionKind dtorKind = elementType.isDestructedType();
526
1.63k
  Address endOfInit = Address::invalid();
527
1.63k
  EHScopeStack::stable_iterator cleanup;
528
1.63k
  llvm::Instruction *cleanupDominator = nullptr;
529
1.63k
  if (CGF.needsEHCleanup(dtorKind)) {
530
    // In principle we could tell the cleanup where we are more
531
    // directly, but the control flow can get so varied here that it
532
    // would actually be quite complex.  Therefore we go through an
533
    // alloca.
534
70
    endOfInit = CGF.CreateTempAlloca(begin->getType(), CGF.getPointerAlign(),
535
70
                                     "arrayinit.endOfInit");
536
70
    cleanupDominator = Builder.CreateStore(begin, endOfInit);
537
70
    CGF.pushIrregularPartialArrayCleanup(begin, endOfInit, elementType,
538
70
                                         elementAlign,
539
70
                                         CGF.getDestroyer(dtorKind));
540
70
    cleanup = CGF.EHStack.stable_begin();
541
542
  // Otherwise, remember that we didn't need a cleanup.
543
1.56k
  } else {
544
1.56k
    dtorKind = QualType::DK_none;
545
1.56k
  }
546
547
1.63k
  llvm::Value *one = llvm::ConstantInt::get(CGF.SizeTy, 1);
548
549
  // The 'current element to initialize'.  The invariants on this
550
  // variable are complicated.  Essentially, after each iteration of
551
  // the loop, it points to the last initialized element, except
552
  // that it points to the beginning of the array before any
553
  // elements have been initialized.
554
1.63k
  llvm::Value *element = begin;
555
556
  // Emit the explicit initializers.
557
4.96k
  for (uint64_t i = 0; i != NumInitElements; 
++i3.33k
) {
558
    // Advance to the next element.
559
3.33k
    if (i > 0) {
560
1.71k
      element = Builder.CreateInBoundsGEP(
561
1.71k
          llvmElementType, element, one, "arrayinit.element");
562
563
      // Tell the cleanup that it needs to destroy up to this
564
      // element.  TODO: some of these stores can be trivially
565
      // observed to be unnecessary.
566
1.71k
      if (endOfInit.isValid()) 
Builder.CreateStore(element, endOfInit)110
;
567
1.71k
    }
568
569
3.33k
    LValue elementLV = CGF.MakeAddrLValue(
570
3.33k
        Address(element, llvmElementType, elementAlign), elementType);
571
3.33k
    EmitInitializationToLValue(E->getInit(i), elementLV);
572
3.33k
  }
573
574
  // Check whether there's a non-trivial array-fill expression.
575
1.63k
  Expr *filler = E->getArrayFiller();
576
1.63k
  bool hasTrivialFiller = isTrivialFiller(filler);
577
578
  // Any remaining elements need to be zero-initialized, possibly
579
  // using the filler expression.  We can skip this if the we're
580
  // emitting to zeroed memory.
581
1.63k
  if (NumInitElements != NumArrayElements &&
582
1.63k
      
!(70
Dest.isZeroed()70
&&
hasTrivialFiller29
&&
583
70
        
CGF.getTypes().isZeroInitializable(elementType)20
)) {
584
585
    // Use an actual loop.  This is basically
586
    //   do { *array++ = filler; } while (array != end);
587
588
    // Advance to the start of the rest of the array.
589
50
    if (NumInitElements) {
590
28
      element = Builder.CreateInBoundsGEP(
591
28
          llvmElementType, element, one, "arrayinit.start");
592
28
      if (endOfInit.isValid()) 
Builder.CreateStore(element, endOfInit)2
;
593
28
    }
594
595
    // Compute the end of the array.
596
50
    llvm::Value *end = Builder.CreateInBoundsGEP(
597
50
        llvmElementType, begin,
598
50
        llvm::ConstantInt::get(CGF.SizeTy, NumArrayElements), "arrayinit.end");
599
600
50
    llvm::BasicBlock *entryBB = Builder.GetInsertBlock();
601
50
    llvm::BasicBlock *bodyBB = CGF.createBasicBlock("arrayinit.body");
602
603
    // Jump into the body.
604
50
    CGF.EmitBlock(bodyBB);
605
50
    llvm::PHINode *currentElement =
606
50
      Builder.CreatePHI(element->getType(), 2, "arrayinit.cur");
607
50
    currentElement->addIncoming(element, entryBB);
608
609
    // Emit the actual filler expression.
610
50
    {
611
      // C++1z [class.temporary]p5:
612
      //   when a default constructor is called to initialize an element of
613
      //   an array with no corresponding initializer [...] the destruction of
614
      //   every temporary created in a default argument is sequenced before
615
      //   the construction of the next array element, if any
616
50
      CodeGenFunction::RunCleanupsScope CleanupsScope(CGF);
617
50
      LValue elementLV = CGF.MakeAddrLValue(
618
50
          Address(currentElement, llvmElementType, elementAlign), elementType);
619
50
      if (filler)
620
50
        EmitInitializationToLValue(filler, elementLV);
621
0
      else
622
0
        EmitNullInitializationToLValue(elementLV);
623
50
    }
624
625
    // Move on to the next element.
626
50
    llvm::Value *nextElement = Builder.CreateInBoundsGEP(
627
50
        llvmElementType, currentElement, one, "arrayinit.next");
628
629
    // Tell the EH cleanup that we finished with the last element.
630
50
    if (endOfInit.isValid()) 
Builder.CreateStore(nextElement, endOfInit)2
;
631
632
    // Leave the loop if we're done.
633
50
    llvm::Value *done = Builder.CreateICmpEQ(nextElement, end,
634
50
                                             "arrayinit.done");
635
50
    llvm::BasicBlock *endBB = CGF.createBasicBlock("arrayinit.end");
636
50
    Builder.CreateCondBr(done, endBB, bodyBB);
637
50
    currentElement->addIncoming(nextElement, Builder.GetInsertBlock());
638
639
50
    CGF.EmitBlock(endBB);
640
50
  }
641
642
  // Leave the partial-array cleanup if we entered one.
643
1.63k
  if (dtorKind) 
CGF.DeactivateCleanupBlock(cleanup, cleanupDominator)70
;
644
1.63k
}
645
646
//===----------------------------------------------------------------------===//
647
//                            Visitor Methods
648
//===----------------------------------------------------------------------===//
649
650
13.4k
void AggExprEmitter::VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E){
651
13.4k
  Visit(E->getSubExpr());
652
13.4k
}
653
654
23
void AggExprEmitter::VisitOpaqueValueExpr(OpaqueValueExpr *e) {
655
  // If this is a unique OVE, just visit its source expression.
656
23
  if (e->isUnique())
657
7
    Visit(e->getSourceExpr());
658
16
  else
659
16
    EmitFinalDestCopy(e->getType(), CGF.getOrCreateOpaqueLValueMapping(e));
660
23
}
661
662
void
663
551
AggExprEmitter::VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
664
551
  if (Dest.isPotentiallyAliased() &&
665
551
      
E->getType().isPODType(CGF.getContext())20
) {
666
    // For a POD type, just emit a load of the lvalue + a copy, because our
667
    // compound literal might alias the destination.
668
20
    EmitAggLoadOfLValue(E);
669
20
    return;
670
20
  }
671
672
531
  AggValueSlot Slot = EnsureSlot(E->getType());
673
674
  // Block-scope compound literals are destroyed at the end of the enclosing
675
  // scope in C.
676
531
  bool Destruct =
677
531
      !CGF.getLangOpts().CPlusPlus && 
!Slot.isExternallyDestructed()221
;
678
531
  if (Destruct)
679
20
    Slot.setExternallyDestructed();
680
681
531
  CGF.EmitAggExpr(E->getInitializer(), Slot);
682
683
531
  if (Destruct)
684
20
    if (QualType::DestructionKind DtorKind = E->getType().isDestructedType())
685
0
      CGF.pushLifetimeExtendedDestroy(
686
0
          CGF.getCleanupKind(DtorKind), Slot.getAddress(), E->getType(),
687
0
          CGF.getDestroyer(DtorKind), DtorKind & EHCleanup);
688
531
}
689
690
/// Attempt to look through various unimportant expressions to find a
691
/// cast of the given kind.
692
11
static Expr *findPeephole(Expr *op, CastKind kind, const ASTContext &ctx) {
693
11
  op = op->IgnoreParenNoopCasts(ctx);
694
11
  if (auto castE = dyn_cast<CastExpr>(op)) {
695
0
    if (castE->getCastKind() == kind)
696
0
      return castE->getSubExpr();
697
0
  }
698
11
  return nullptr;
699
11
}
700
701
13.2k
void AggExprEmitter::VisitCastExpr(CastExpr *E) {
702
13.2k
  if (const auto *ECE = dyn_cast<ExplicitCastExpr>(E))
703
3.54k
    CGF.CGM.EmitExplicitCastExprType(ECE, &CGF);
704
13.2k
  switch (E->getCastKind()) {
705
0
  case CK_Dynamic: {
706
    // FIXME: Can this actually happen? We have no test coverage for it.
707
0
    assert(isa<CXXDynamicCastExpr>(E) && "CK_Dynamic without a dynamic_cast?");
708
0
    LValue LV = CGF.EmitCheckedLValue(E->getSubExpr(),
709
0
                                      CodeGenFunction::TCK_Load);
710
    // FIXME: Do we also need to handle property references here?
711
0
    if (LV.isSimple())
712
0
      CGF.EmitDynamicCast(LV.getAddress(CGF), cast<CXXDynamicCastExpr>(E));
713
0
    else
714
0
      CGF.CGM.ErrorUnsupported(E, "non-simple lvalue dynamic_cast");
715
716
0
    if (!Dest.isIgnored())
717
0
      CGF.CGM.ErrorUnsupported(E, "lvalue dynamic_cast with a destination");
718
0
    break;
719
0
  }
720
721
7
  case CK_ToUnion: {
722
    // Evaluate even if the destination is ignored.
723
7
    if (Dest.isIgnored()) {
724
1
      CGF.EmitAnyExpr(E->getSubExpr(), AggValueSlot::ignored(),
725
1
                      /*ignoreResult=*/true);
726
1
      break;
727
1
    }
728
729
    // GCC union extension
730
6
    QualType Ty = E->getSubExpr()->getType();
731
6
    Address CastPtr =
732
6
      Builder.CreateElementBitCast(Dest.getAddress(), CGF.ConvertType(Ty));
733
6
    EmitInitializationToLValue(E->getSubExpr(),
734
6
                               CGF.MakeAddrLValue(CastPtr, Ty));
735
6
    break;
736
7
  }
737
738
4
  case CK_LValueToRValueBitCast: {
739
4
    if (Dest.isIgnored()) {
740
0
      CGF.EmitAnyExpr(E->getSubExpr(), AggValueSlot::ignored(),
741
0
                      /*ignoreResult=*/true);
742
0
      break;
743
0
    }
744
745
4
    LValue SourceLV = CGF.EmitLValue(E->getSubExpr());
746
4
    Address SourceAddress =
747
4
        Builder.CreateElementBitCast(SourceLV.getAddress(CGF), CGF.Int8Ty);
748
4
    Address DestAddress =
749
4
        Builder.CreateElementBitCast(Dest.getAddress(), CGF.Int8Ty);
750
4
    llvm::Value *SizeVal = llvm::ConstantInt::get(
751
4
        CGF.SizeTy,
752
4
        CGF.getContext().getTypeSizeInChars(E->getType()).getQuantity());
753
4
    Builder.CreateMemCpy(DestAddress, SourceAddress, SizeVal);
754
4
    break;
755
4
  }
756
757
0
  case CK_DerivedToBase:
758
0
  case CK_BaseToDerived:
759
0
  case CK_UncheckedDerivedToBase: {
760
0
    llvm_unreachable("cannot perform hierarchy conversion in EmitAggExpr: "
761
0
                "should have been unpacked before we got here");
762
0
  }
763
764
19
  case CK_NonAtomicToAtomic:
765
29
  case CK_AtomicToNonAtomic: {
766
29
    bool isToAtomic = (E->getCastKind() == CK_NonAtomicToAtomic);
767
768
    // Determine the atomic and value types.
769
29
    QualType atomicType = E->getSubExpr()->getType();
770
29
    QualType valueType = E->getType();
771
29
    if (isToAtomic) 
std::swap(atomicType, valueType)19
;
772
773
29
    assert(atomicType->isAtomicType());
774
0
    assert(CGF.getContext().hasSameUnqualifiedType(valueType,
775
29
                          atomicType->castAs<AtomicType>()->getValueType()));
776
777
    // Just recurse normally if we're ignoring the result or the
778
    // atomic type doesn't change representation.
779
29
    if (Dest.isIgnored() || !CGF.CGM.isPaddedAtomicType(atomicType)) {
780
18
      return Visit(E->getSubExpr());
781
18
    }
782
783
11
    CastKind peepholeTarget =
784
11
      (isToAtomic ? 
CK_AtomicToNonAtomic7
:
CK_NonAtomicToAtomic4
);
785
786
    // These two cases are reverses of each other; try to peephole them.
787
11
    if (Expr *op =
788
11
            findPeephole(E->getSubExpr(), peepholeTarget, CGF.getContext())) {
789
0
      assert(CGF.getContext().hasSameUnqualifiedType(op->getType(),
790
0
                                                     E->getType()) &&
791
0
           "peephole significantly changed types?");
792
0
      return Visit(op);
793
0
    }
794
795
    // If we're converting an r-value of non-atomic type to an r-value
796
    // of atomic type, just emit directly into the relevant sub-object.
797
11
    if (isToAtomic) {
798
7
      AggValueSlot valueDest = Dest;
799
7
      if (!valueDest.isIgnored() && CGF.CGM.isPaddedAtomicType(atomicType)) {
800
        // Zero-initialize.  (Strictly speaking, we only need to initialize
801
        // the padding at the end, but this is simpler.)
802
7
        if (!Dest.isZeroed())
803
7
          CGF.EmitNullInitialization(Dest.getAddress(), atomicType);
804
805
        // Build a GEP to refer to the subobject.
806
7
        Address valueAddr =
807
7
            CGF.Builder.CreateStructGEP(valueDest.getAddress(), 0);
808
7
        valueDest = AggValueSlot::forAddr(valueAddr,
809
7
                                          valueDest.getQualifiers(),
810
7
                                          valueDest.isExternallyDestructed(),
811
7
                                          valueDest.requiresGCollection(),
812
7
                                          valueDest.isPotentiallyAliased(),
813
7
                                          AggValueSlot::DoesNotOverlap,
814
7
                                          AggValueSlot::IsZeroed);
815
7
      }
816
817
7
      CGF.EmitAggExpr(E->getSubExpr(), valueDest);
818
7
      return;
819
7
    }
820
821
    // Otherwise, we're converting an atomic type to a non-atomic type.
822
    // Make an atomic temporary, emit into that, and then copy the value out.
823
4
    AggValueSlot atomicSlot =
824
4
      CGF.CreateAggTemp(atomicType, "atomic-to-nonatomic.temp");
825
4
    CGF.EmitAggExpr(E->getSubExpr(), atomicSlot);
826
827
4
    Address valueAddr = Builder.CreateStructGEP(atomicSlot.getAddress(), 0);
828
4
    RValue rvalue = RValue::getAggregate(valueAddr, atomicSlot.isVolatile());
829
4
    return EmitFinalDestCopy(valueType, rvalue);
830
11
  }
831
0
  case CK_AddressSpaceConversion:
832
0
     return Visit(E->getSubExpr());
833
834
2.73k
  case CK_LValueToRValue:
835
    // If we're loading from a volatile type, force the destination
836
    // into existence.
837
2.73k
    if (E->getSubExpr()->getType().isVolatileQualified()) {
838
24
      bool Destruct =
839
24
          !Dest.isExternallyDestructed() &&
840
24
          
E->getType().isDestructedType() == QualType::DK_nontrivial_c_struct12
;
841
24
      if (Destruct)
842
2
        Dest.setExternallyDestructed();
843
24
      EnsureDest(E->getType());
844
24
      Visit(E->getSubExpr());
845
846
24
      if (Destruct)
847
2
        CGF.pushDestroy(QualType::DK_nontrivial_c_struct, Dest.getAddress(),
848
2
                        E->getType());
849
850
24
      return;
851
24
    }
852
853
2.73k
    
LLVM_FALLTHROUGH2.71k
;2.71k
854
855
856
6.74k
  case CK_NoOp:
857
6.81k
  case CK_UserDefinedConversion:
858
13.2k
  case CK_ConstructorConversion:
859
13.2k
    assert(CGF.getContext().hasSameUnqualifiedType(E->getSubExpr()->getType(),
860
13.2k
                                                   E->getType()) &&
861
13.2k
           "Implicit cast types must be compatible");
862
0
    Visit(E->getSubExpr());
863
13.2k
    break;
864
865
0
  case CK_LValueBitCast:
866
0
    llvm_unreachable("should not be emitting lvalue bitcast as rvalue");
867
868
0
  case CK_Dependent:
869
0
  case CK_BitCast:
870
0
  case CK_ArrayToPointerDecay:
871
0
  case CK_FunctionToPointerDecay:
872
0
  case CK_NullToPointer:
873
0
  case CK_NullToMemberPointer:
874
0
  case CK_BaseToDerivedMemberPointer:
875
0
  case CK_DerivedToBaseMemberPointer:
876
0
  case CK_MemberPointerToBoolean:
877
0
  case CK_ReinterpretMemberPointer:
878
0
  case CK_IntegralToPointer:
879
0
  case CK_PointerToIntegral:
880
0
  case CK_PointerToBoolean:
881
0
  case CK_ToVoid:
882
0
  case CK_VectorSplat:
883
0
  case CK_IntegralCast:
884
0
  case CK_BooleanToSignedIntegral:
885
0
  case CK_IntegralToBoolean:
886
0
  case CK_IntegralToFloating:
887
0
  case CK_FloatingToIntegral:
888
0
  case CK_FloatingToBoolean:
889
0
  case CK_FloatingCast:
890
0
  case CK_CPointerToObjCPointerCast:
891
0
  case CK_BlockPointerToObjCPointerCast:
892
0
  case CK_AnyPointerToBlockPointerCast:
893
0
  case CK_ObjCObjectLValueCast:
894
0
  case CK_FloatingRealToComplex:
895
0
  case CK_FloatingComplexToReal:
896
0
  case CK_FloatingComplexToBoolean:
897
0
  case CK_FloatingComplexCast:
898
0
  case CK_FloatingComplexToIntegralComplex:
899
0
  case CK_IntegralRealToComplex:
900
0
  case CK_IntegralComplexToReal:
901
0
  case CK_IntegralComplexToBoolean:
902
0
  case CK_IntegralComplexCast:
903
0
  case CK_IntegralComplexToFloatingComplex:
904
0
  case CK_ARCProduceObject:
905
0
  case CK_ARCConsumeObject:
906
0
  case CK_ARCReclaimReturnedObject:
907
0
  case CK_ARCExtendBlockObject:
908
0
  case CK_CopyAndAutoreleaseBlockObject:
909
0
  case CK_BuiltinFnToFnPtr:
910
0
  case CK_ZeroToOCLOpaqueType:
911
0
  case CK_MatrixCast:
912
913
0
  case CK_IntToOCLSampler:
914
0
  case CK_FloatingToFixedPoint:
915
0
  case CK_FixedPointToFloating:
916
0
  case CK_FixedPointCast:
917
0
  case CK_FixedPointToBoolean:
918
0
  case CK_FixedPointToIntegral:
919
0
  case CK_IntegralToFixedPoint:
920
0
    llvm_unreachable("cast kind invalid for aggregate types");
921
13.2k
  }
922
13.2k
}
923
924
7.51k
void AggExprEmitter::VisitCallExpr(const CallExpr *E) {
925
7.51k
  if (E->getCallReturnType(CGF.getContext())->isReferenceType()) {
926
0
    EmitAggLoadOfLValue(E);
927
0
    return;
928
0
  }
929
930
7.51k
  withReturnValueSlot(E, [&](ReturnValueSlot Slot) {
931
7.51k
    return CGF.EmitCallExpr(E, Slot);
932
7.51k
  });
933
7.51k
}
934
935
73
void AggExprEmitter::VisitObjCMessageExpr(ObjCMessageExpr *E) {
936
73
  withReturnValueSlot(E, [&](ReturnValueSlot Slot) {
937
73
    return CGF.EmitObjCMessageExpr(E, Slot);
938
73
  });
939
73
}
940
941
44
void AggExprEmitter::VisitBinComma(const BinaryOperator *E) {
942
44
  CGF.EmitIgnoredExpr(E->getLHS());
943
44
  Visit(E->getRHS());
944
44
}
945
946
647
void AggExprEmitter::VisitStmtExpr(const StmtExpr *E) {
947
647
  CodeGenFunction::StmtExprEvaluation eval(CGF);
948
647
  CGF.EmitCompoundStmt(*E->getSubStmt(), true, Dest);
949
647
}
950
951
enum CompareKind {
952
  CK_Less,
953
  CK_Greater,
954
  CK_Equal,
955
};
956
957
static llvm::Value *EmitCompare(CGBuilderTy &Builder, CodeGenFunction &CGF,
958
                                const BinaryOperator *E, llvm::Value *LHS,
959
                                llvm::Value *RHS, CompareKind Kind,
960
31
                                const char *NameSuffix = "") {
961
31
  QualType ArgTy = E->getLHS()->getType();
962
31
  if (const ComplexType *CT = ArgTy->getAs<ComplexType>())
963
0
    ArgTy = CT->getElementType();
964
965
31
  if (const auto *MPT = ArgTy->getAs<MemberPointerType>()) {
966
0
    assert(Kind == CK_Equal &&
967
0
           "member pointers may only be compared for equality");
968
0
    return CGF.CGM.getCXXABI().EmitMemberPointerComparison(
969
0
        CGF, LHS, RHS, MPT, /*IsInequality*/ false);
970
0
  }
971
972
  // Compute the comparison instructions for the specified comparison kind.
973
31
  struct CmpInstInfo {
974
31
    const char *Name;
975
31
    llvm::CmpInst::Predicate FCmp;
976
31
    llvm::CmpInst::Predicate SCmp;
977
31
    llvm::CmpInst::Predicate UCmp;
978
31
  };
979
31
  CmpInstInfo InstInfo = [&]() -> CmpInstInfo {
980
31
    using FI = llvm::FCmpInst;
981
31
    using II = llvm::ICmpInst;
982
31
    switch (Kind) {
983
15
    case CK_Less:
984
15
      return {"cmp.lt", FI::FCMP_OLT, II::ICMP_SLT, II::ICMP_ULT};
985
1
    case CK_Greater:
986
1
      return {"cmp.gt", FI::FCMP_OGT, II::ICMP_SGT, II::ICMP_UGT};
987
15
    case CK_Equal:
988
15
      return {"cmp.eq", FI::FCMP_OEQ, II::ICMP_EQ, II::ICMP_EQ};
989
31
    }
990
0
    llvm_unreachable("Unrecognised CompareKind enum");
991
0
  }();
992
993
31
  if (ArgTy->hasFloatingRepresentation())
994
3
    return Builder.CreateFCmp(InstInfo.FCmp, LHS, RHS,
995
3
                              llvm::Twine(InstInfo.Name) + NameSuffix);
996
28
  if (ArgTy->isIntegralOrEnumerationType() || 
ArgTy->isPointerType()2
) {
997
28
    auto Inst =
998
28
        ArgTy->hasSignedIntegerRepresentation() ? 
InstInfo.SCmp18
:
InstInfo.UCmp10
;
999
28
    return Builder.CreateICmp(Inst, LHS, RHS,
1000
28
                              llvm::Twine(InstInfo.Name) + NameSuffix);
1001
28
  }
1002
1003
0
  llvm_unreachable("unsupported aggregate binary expression should have "
1004
0
                   "already been handled");
1005
0
}
1006
1007
15
void AggExprEmitter::VisitBinCmp(const BinaryOperator *E) {
1008
15
  using llvm::BasicBlock;
1009
15
  using llvm::PHINode;
1010
15
  using llvm::Value;
1011
15
  assert(CGF.getContext().hasSameType(E->getLHS()->getType(),
1012
15
                                      E->getRHS()->getType()));
1013
0
  const ComparisonCategoryInfo &CmpInfo =
1014
15
      CGF.getContext().CompCategories.getInfoForType(E->getType());
1015
15
  assert(CmpInfo.Record->isTriviallyCopyable() &&
1016
15
         "cannot copy non-trivially copyable aggregate");
1017
1018
0
  QualType ArgTy = E->getLHS()->getType();
1019
1020
15
  if (!ArgTy->isIntegralOrEnumerationType() && 
!ArgTy->isRealFloatingType()2
&&
1021
15
      
!ArgTy->isNullPtrType()1
&&
!ArgTy->isPointerType()1
&&
1022
15
      
!ArgTy->isMemberPointerType()0
&&
!ArgTy->isAnyComplexType()0
) {
1023
0
    return CGF.ErrorUnsupported(E, "aggregate three-way comparison");
1024
0
  }
1025
15
  bool IsComplex = ArgTy->isAnyComplexType();
1026
1027
  // Evaluate the operands to the expression and extract their values.
1028
30
  auto EmitOperand = [&](Expr *E) -> std::pair<Value *, Value *> {
1029
30
    RValue RV = CGF.EmitAnyExpr(E);
1030
30
    if (RV.isScalar())
1031
30
      return {RV.getScalarVal(), nullptr};
1032
0
    if (RV.isAggregate())
1033
0
      return {RV.getAggregatePointer(), nullptr};
1034
0
    assert(RV.isComplex());
1035
0
    return RV.getComplexVal();
1036
0
  };
1037
15
  auto LHSValues = EmitOperand(E->getLHS()),
1038
15
       RHSValues = EmitOperand(E->getRHS());
1039
1040
31
  auto EmitCmp = [&](CompareKind K) {
1041
31
    Value *Cmp = EmitCompare(Builder, CGF, E, LHSValues.first, RHSValues.first,
1042
31
                             K, IsComplex ? 
".r"0
: "");
1043
31
    if (!IsComplex)
1044
31
      return Cmp;
1045
0
    assert(K == CompareKind::CK_Equal);
1046
0
    Value *CmpImag = EmitCompare(Builder, CGF, E, LHSValues.second,
1047
0
                                 RHSValues.second, K, ".i");
1048
0
    return Builder.CreateAnd(Cmp, CmpImag, "and.eq");
1049
31
  };
1050
46
  auto EmitCmpRes = [&](const ComparisonCategoryInfo::ValueInfo *VInfo) {
1051
46
    return Builder.getInt(VInfo->getIntValue());
1052
46
  };
1053
1054
15
  Value *Select;
1055
15
  if (ArgTy->isNullPtrType()) {
1056
0
    Select = EmitCmpRes(CmpInfo.getEqualOrEquiv());
1057
15
  } else if (!CmpInfo.isPartial()) {
1058
14
    Value *SelectOne =
1059
14
        Builder.CreateSelect(EmitCmp(CK_Less), EmitCmpRes(CmpInfo.getLess()),
1060
14
                             EmitCmpRes(CmpInfo.getGreater()), "sel.lt");
1061
14
    Select = Builder.CreateSelect(EmitCmp(CK_Equal),
1062
14
                                  EmitCmpRes(CmpInfo.getEqualOrEquiv()),
1063
14
                                  SelectOne, "sel.eq");
1064
14
  } else {
1065
1
    Value *SelectEq = Builder.CreateSelect(
1066
1
        EmitCmp(CK_Equal), EmitCmpRes(CmpInfo.getEqualOrEquiv()),
1067
1
        EmitCmpRes(CmpInfo.getUnordered()), "sel.eq");
1068
1
    Value *SelectGT = Builder.CreateSelect(EmitCmp(CK_Greater),
1069
1
                                           EmitCmpRes(CmpInfo.getGreater()),
1070
1
                                           SelectEq, "sel.gt");
1071
1
    Select = Builder.CreateSelect(
1072
1
        EmitCmp(CK_Less), EmitCmpRes(CmpInfo.getLess()), SelectGT, "sel.lt");
1073
1
  }
1074
  // Create the return value in the destination slot.
1075
15
  EnsureDest(E->getType());
1076
15
  LValue DestLV = CGF.MakeAddrLValue(Dest.getAddress(), E->getType());
1077
1078
  // Emit the address of the first (and only) field in the comparison category
1079
  // type, and initialize it from the constant integer value selected above.
1080
15
  LValue FieldLV = CGF.EmitLValueForFieldInitialization(
1081
15
      DestLV, *CmpInfo.Record->field_begin());
1082
15
  CGF.EmitStoreThroughLValue(RValue::get(Select), FieldLV, /*IsInit*/ true);
1083
1084
  // All done! The result is in the Dest slot.
1085
15
}
1086
1087
0
void AggExprEmitter::VisitBinaryOperator(const BinaryOperator *E) {
1088
0
  if (E->getOpcode() == BO_PtrMemD || E->getOpcode() == BO_PtrMemI)
1089
0
    VisitPointerToDataMemberBinaryOperator(E);
1090
0
  else
1091
0
    CGF.ErrorUnsupported(E, "aggregate binary expression");
1092
0
}
1093
1094
void AggExprEmitter::VisitPointerToDataMemberBinaryOperator(
1095
0
                                                    const BinaryOperator *E) {
1096
0
  LValue LV = CGF.EmitPointerToDataMemberBinaryExpr(E);
1097
0
  EmitFinalDestCopy(E->getType(), LV);
1098
0
}
1099
1100
/// Is the value of the given expression possibly a reference to or
1101
/// into a __block variable?
1102
702
static bool isBlockVarRef(const Expr *E) {
1103
  // Make sure we look through parens.
1104
702
  E = E->IgnoreParens();
1105
1106
  // Check for a direct reference to a __block variable.
1107
702
  if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
1108
242
    const VarDecl *var = dyn_cast<VarDecl>(DRE->getDecl());
1109
242
    return (var && var->hasAttr<BlocksAttr>());
1110
242
  }
1111
1112
  // More complicated stuff.
1113
1114
  // Binary operators.
1115
460
  if (const BinaryOperator *op = dyn_cast<BinaryOperator>(E)) {
1116
    // For an assignment or pointer-to-member operation, just care
1117
    // about the LHS.
1118
0
    if (op->isAssignmentOp() || op->isPtrMemOp())
1119
0
      return isBlockVarRef(op->getLHS());
1120
1121
    // For a comma, just care about the RHS.
1122
0
    if (op->getOpcode() == BO_Comma)
1123
0
      return isBlockVarRef(op->getRHS());
1124
1125
    // FIXME: pointer arithmetic?
1126
0
    return false;
1127
1128
  // Check both sides of a conditional operator.
1129
460
  } else if (const AbstractConditionalOperator *op
1130
460
               = dyn_cast<AbstractConditionalOperator>(E)) {
1131
0
    return isBlockVarRef(op->getTrueExpr())
1132
0
        || isBlockVarRef(op->getFalseExpr());
1133
1134
  // OVEs are required to support BinaryConditionalOperators.
1135
460
  } else if (const OpaqueValueExpr *op
1136
460
               = dyn_cast<OpaqueValueExpr>(E)) {
1137
0
    if (const Expr *src = op->getSourceExpr())
1138
0
      return isBlockVarRef(src);
1139
1140
  // Casts are necessary to get things like (*(int*)&var) = foo().
1141
  // We don't really care about the kind of cast here, except
1142
  // we don't want to look through l2r casts, because it's okay
1143
  // to get the *value* in a __block variable.
1144
460
  } else if (const CastExpr *cast = dyn_cast<CastExpr>(E)) {
1145
231
    if (cast->getCastKind() == CK_LValueToRValue)
1146
217
      return false;
1147
14
    return isBlockVarRef(cast->getSubExpr());
1148
1149
  // Handle unary operators.  Again, just aggressively look through
1150
  // it, ignoring the operation.
1151
231
  } else 
if (const UnaryOperator *229
uop229
= dyn_cast<UnaryOperator>(E)) {
1152
200
    return isBlockVarRef(uop->getSubExpr());
1153
1154
  // Look into the base of a field access.
1155
200
  } else 
if (const MemberExpr *29
mem29
= dyn_cast<MemberExpr>(E)) {
1156
5
    return isBlockVarRef(mem->getBase());
1157
1158
  // Look into the base of a subscript.
1159
24
  } else if (const ArraySubscriptExpr *sub = dyn_cast<ArraySubscriptExpr>(E)) {
1160
17
    return isBlockVarRef(sub->getBase());
1161
17
  }
1162
1163
7
  return false;
1164
460
}
1165
1166
466
void AggExprEmitter::VisitBinAssign(const BinaryOperator *E) {
1167
  // For an assignment to work, the value on the right has
1168
  // to be compatible with the value on the left.
1169
466
  assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
1170
466
                                                 E->getRHS()->getType())
1171
466
         && "Invalid assignment");
1172
1173
  // If the LHS might be a __block variable, and the RHS can
1174
  // potentially cause a block copy, we need to evaluate the RHS first
1175
  // so that the assignment goes the right place.
1176
  // This is pretty semantically fragile.
1177
466
  if (isBlockVarRef(E->getLHS()) &&
1178
466
      
E->getRHS()->HasSideEffects(CGF.getContext())3
) {
1179
    // Ensure that we have a destination, and evaluate the RHS into that.
1180
3
    EnsureDest(E->getRHS()->getType());
1181
3
    Visit(E->getRHS());
1182
1183
    // Now emit the LHS and copy into it.
1184
3
    LValue LHS = CGF.EmitCheckedLValue(E->getLHS(), CodeGenFunction::TCK_Store);
1185
1186
    // That copy is an atomic copy if the LHS is atomic.
1187
3
    if (LHS.getType()->isAtomicType() ||
1188
3
        CGF.LValueIsSuitableForInlineAtomic(LHS)) {
1189
0
      CGF.EmitAtomicStore(Dest.asRValue(), LHS, /*isInit*/ false);
1190
0
      return;
1191
0
    }
1192
1193
3
    EmitCopy(E->getLHS()->getType(),
1194
3
             AggValueSlot::forLValue(LHS, CGF, AggValueSlot::IsDestructed,
1195
3
                                     needsGC(E->getLHS()->getType()),
1196
3
                                     AggValueSlot::IsAliased,
1197
3
                                     AggValueSlot::MayOverlap),
1198
3
             Dest);
1199
3
    return;
1200
3
  }
1201
1202
463
  LValue LHS = CGF.EmitLValue(E->getLHS());
1203
1204
  // If we have an atomic type, evaluate into the destination and then
1205
  // do an atomic copy.
1206
463
  if (LHS.getType()->isAtomicType() ||
1207
463
      
CGF.LValueIsSuitableForInlineAtomic(LHS)454
) {
1208
12
    EnsureDest(E->getRHS()->getType());
1209
12
    Visit(E->getRHS());
1210
12
    CGF.EmitAtomicStore(Dest.asRValue(), LHS, /*isInit*/ false);
1211
12
    return;
1212
12
  }
1213
1214
  // Codegen the RHS so that it stores directly into the LHS.
1215
451
  AggValueSlot LHSSlot = AggValueSlot::forLValue(
1216
451
      LHS, CGF, AggValueSlot::IsDestructed, needsGC(E->getLHS()->getType()),
1217
451
      AggValueSlot::IsAliased, AggValueSlot::MayOverlap);
1218
  // A non-volatile aggregate destination might have volatile member.
1219
451
  if (!LHSSlot.isVolatile() &&
1220
451
      
CGF.hasVolatileMember(E->getLHS()->getType())435
)
1221
7
    LHSSlot.setVolatile(true);
1222
1223
451
  CGF.EmitAggExpr(E->getRHS(), LHSSlot);
1224
1225
  // Copy into the destination if the assignment isn't ignored.
1226
451
  EmitFinalDestCopy(E->getType(), LHS);
1227
1228
451
  if (!Dest.isIgnored() && 
!Dest.isExternallyDestructed()9
&&
1229
451
      
E->getType().isDestructedType() == QualType::DK_nontrivial_c_struct4
)
1230
2
    CGF.pushDestroy(QualType::DK_nontrivial_c_struct, Dest.getAddress(),
1231
2
                    E->getType());
1232
451
}
1233
1234
void AggExprEmitter::
1235
63
VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
1236
63
  llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
1237
63
  llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
1238
63
  llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
1239
1240
  // Bind the common expression if necessary.
1241
63
  CodeGenFunction::OpaqueValueMapping binding(CGF, E);
1242
1243
63
  CodeGenFunction::ConditionalEvaluation eval(CGF);
1244
63
  CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock,
1245
63
                           CGF.getProfileCount(E));
1246
1247
  // Save whether the destination's lifetime is externally managed.
1248
63
  bool isExternallyDestructed = Dest.isExternallyDestructed();
1249
63
  bool destructNonTrivialCStruct =
1250
63
      !isExternallyDestructed &&
1251
63
      
E->getType().isDestructedType() == QualType::DK_nontrivial_c_struct12
;
1252
63
  isExternallyDestructed |= destructNonTrivialCStruct;
1253
63
  Dest.setExternallyDestructed(isExternallyDestructed);
1254
1255
63
  eval.begin(CGF);
1256
63
  CGF.EmitBlock(LHSBlock);
1257
63
  CGF.incrementProfileCounter(E);
1258
63
  Visit(E->getTrueExpr());
1259
63
  eval.end(CGF);
1260
1261
63
  assert(CGF.HaveInsertPoint() && "expression evaluation ended with no IP!");
1262
0
  CGF.Builder.CreateBr(ContBlock);
1263
1264
  // If the result of an agg expression is unused, then the emission
1265
  // of the LHS might need to create a destination slot.  That's fine
1266
  // with us, and we can safely emit the RHS into the same slot, but
1267
  // we shouldn't claim that it's already being destructed.
1268
63
  Dest.setExternallyDestructed(isExternallyDestructed);
1269
1270
63
  eval.begin(CGF);
1271
63
  CGF.EmitBlock(RHSBlock);
1272
63
  Visit(E->getFalseExpr());
1273
63
  eval.end(CGF);
1274
1275
63
  if (destructNonTrivialCStruct)
1276
2
    CGF.pushDestroy(QualType::DK_nontrivial_c_struct, Dest.getAddress(),
1277
2
                    E->getType());
1278
1279
63
  CGF.EmitBlock(ContBlock);
1280
63
}
1281
1282
0
void AggExprEmitter::VisitChooseExpr(const ChooseExpr *CE) {
1283
0
  Visit(CE->getChosenSubExpr());
1284
0
}
1285
1286
346
void AggExprEmitter::VisitVAArgExpr(VAArgExpr *VE) {
1287
346
  Address ArgValue = Address::invalid();
1288
346
  Address ArgPtr = CGF.EmitVAArg(VE, ArgValue);
1289
1290
  // If EmitVAArg fails, emit an error.
1291
346
  if (!ArgPtr.isValid()) {
1292
0
    CGF.ErrorUnsupported(VE, "aggregate va_arg expression");
1293
0
    return;
1294
0
  }
1295
1296
346
  EmitFinalDestCopy(VE->getType(), CGF.MakeAddrLValue(ArgPtr, VE->getType()));
1297
346
}
1298
1299
7.46k
void AggExprEmitter::VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
1300
  // Ensure that we have a slot, but if we already do, remember
1301
  // whether it was externally destructed.
1302
7.46k
  bool wasExternallyDestructed = Dest.isExternallyDestructed();
1303
7.46k
  EnsureDest(E->getType());
1304
1305
  // We're going to push a destructor if there isn't already one.
1306
7.46k
  Dest.setExternallyDestructed();
1307
1308
7.46k
  Visit(E->getSubExpr());
1309
1310
  // Push that destructor we promised.
1311
7.46k
  if (!wasExternallyDestructed)
1312
787
    CGF.EmitCXXTemporary(E->getTemporary(), E->getType(), Dest.getAddress());
1313
7.46k
}
1314
1315
void
1316
66.0k
AggExprEmitter::VisitCXXConstructExpr(const CXXConstructExpr *E) {
1317
66.0k
  AggValueSlot Slot = EnsureSlot(E->getType());
1318
66.0k
  CGF.EmitCXXConstructExpr(E, Slot);
1319
66.0k
}
1320
1321
void AggExprEmitter::VisitCXXInheritedCtorInitExpr(
1322
200
    const CXXInheritedCtorInitExpr *E) {
1323
200
  AggValueSlot Slot = EnsureSlot(E->getType());
1324
200
  CGF.EmitInheritedCXXConstructorCall(
1325
200
      E->getConstructor(), E->constructsVBase(), Slot.getAddress(),
1326
200
      E->inheritedFromVBase(), E);
1327
200
}
1328
1329
void
1330
1.68k
AggExprEmitter::VisitLambdaExpr(LambdaExpr *E) {
1331
1.68k
  AggValueSlot Slot = EnsureSlot(E->getType());
1332
1.68k
  LValue SlotLV = CGF.MakeAddrLValue(Slot.getAddress(), E->getType());
1333
1334
  // We'll need to enter cleanup scopes in case any of the element
1335
  // initializers throws an exception.
1336
1.68k
  SmallVector<EHScopeStack::stable_iterator, 16> Cleanups;
1337
1.68k
  llvm::Instruction *CleanupDominator = nullptr;
1338
1339
1.68k
  CXXRecordDecl::field_iterator CurField = E->getLambdaClass()->field_begin();
1340
1.68k
  for (LambdaExpr::const_capture_init_iterator i = E->capture_init_begin(),
1341
1.68k
                                               e = E->capture_init_end();
1342
4.40k
       i != e; 
++i, ++CurField2.71k
) {
1343
    // Emit initialization
1344
2.71k
    LValue LV = CGF.EmitLValueForFieldInitialization(SlotLV, *CurField);
1345
2.71k
    if (CurField->hasCapturedVLAType()) {
1346
24
      CGF.EmitLambdaVLACapture(CurField->getCapturedVLAType(), LV);
1347
24
      continue;
1348
24
    }
1349
1350
2.69k
    EmitInitializationToLValue(*i, LV);
1351
1352
    // Push a destructor if necessary.
1353
2.69k
    if (QualType::DestructionKind DtorKind =
1354
2.69k
            CurField->getType().isDestructedType()) {
1355
26
      assert(LV.isSimple());
1356
26
      if (CGF.needsEHCleanup(DtorKind)) {
1357
19
        if (!CleanupDominator)
1358
18
          CleanupDominator = CGF.Builder.CreateAlignedLoad(
1359
18
              CGF.Int8Ty,
1360
18
              llvm::Constant::getNullValue(CGF.Int8PtrTy),
1361
18
              CharUnits::One()); // placeholder
1362
1363
19
        CGF.pushDestroy(EHCleanup, LV.getAddress(CGF), CurField->getType(),
1364
19
                        CGF.getDestroyer(DtorKind), false);
1365
19
        Cleanups.push_back(CGF.EHStack.stable_begin());
1366
19
      }
1367
26
    }
1368
2.69k
  }
1369
1370
  // Deactivate all the partial cleanups in reverse order, which
1371
  // generally means popping them.
1372
1.70k
  for (unsigned i = Cleanups.size(); i != 0; 
--i19
)
1373
19
    CGF.DeactivateCleanupBlock(Cleanups[i-1], CleanupDominator);
1374
1375
  // Destroy the placeholder if we made one.
1376
1.68k
  if (CleanupDominator)
1377
18
    CleanupDominator->eraseFromParent();
1378
1.68k
}
1379
1380
6.95k
void AggExprEmitter::VisitExprWithCleanups(ExprWithCleanups *E) {
1381
6.95k
  CodeGenFunction::RunCleanupsScope cleanups(CGF);
1382
6.95k
  Visit(E->getSubExpr());
1383
6.95k
}
1384
1385
0
void AggExprEmitter::VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E) {
1386
0
  QualType T = E->getType();
1387
0
  AggValueSlot Slot = EnsureSlot(T);
1388
0
  EmitNullInitializationToLValue(CGF.MakeAddrLValue(Slot.getAddress(), T));
1389
0
}
1390
1391
19
void AggExprEmitter::VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) {
1392
19
  QualType T = E->getType();
1393
19
  AggValueSlot Slot = EnsureSlot(T);
1394
19
  EmitNullInitializationToLValue(CGF.MakeAddrLValue(Slot.getAddress(), T));
1395
19
}
1396
1397
/// Determine whether the given cast kind is known to always convert values
1398
/// with all zero bits in their value representation to values with all zero
1399
/// bits in their value representation.
1400
568
static bool castPreservesZero(const CastExpr *CE) {
1401
568
  switch (CE->getCastKind()) {
1402
    // No-ops.
1403
15
  case CK_NoOp:
1404
15
  case CK_UserDefinedConversion:
1405
15
  case CK_ConstructorConversion:
1406
131
  case CK_BitCast:
1407
131
  case CK_ToUnion:
1408
131
  case CK_ToVoid:
1409
    // Conversions between (possibly-complex) integral, (possibly-complex)
1410
    // floating-point, and bool.
1411
131
  case CK_BooleanToSignedIntegral:
1412
132
  case CK_FloatingCast:
1413
132
  case CK_FloatingComplexCast:
1414
132
  case CK_FloatingComplexToBoolean:
1415
132
  case CK_FloatingComplexToIntegralComplex:
1416
132
  case CK_FloatingComplexToReal:
1417
136
  case CK_FloatingRealToComplex:
1418
136
  case CK_FloatingToBoolean:
1419
143
  case CK_FloatingToIntegral:
1420
346
  case CK_IntegralCast:
1421
346
  case CK_IntegralComplexCast:
1422
346
  case CK_IntegralComplexToBoolean:
1423
346
  case CK_IntegralComplexToFloatingComplex:
1424
350
  case CK_IntegralComplexToReal:
1425
354
  case CK_IntegralRealToComplex:
1426
354
  case CK_IntegralToBoolean:
1427
362
  case CK_IntegralToFloating:
1428
    // Reinterpreting integers as pointers and vice versa.
1429
366
  case CK_IntegralToPointer:
1430
369
  case CK_PointerToIntegral:
1431
    // Language extensions.
1432
373
  case CK_VectorSplat:
1433
373
  case CK_MatrixCast:
1434
375
  case CK_NonAtomicToAtomic:
1435
377
  case CK_AtomicToNonAtomic:
1436
377
    return true;
1437
1438
0
  case CK_BaseToDerivedMemberPointer:
1439
0
  case CK_DerivedToBaseMemberPointer:
1440
0
  case CK_MemberPointerToBoolean:
1441
0
  case CK_NullToMemberPointer:
1442
0
  case CK_ReinterpretMemberPointer:
1443
    // FIXME: ABI-dependent.
1444
0
    return false;
1445
1446
0
  case CK_AnyPointerToBlockPointerCast:
1447
0
  case CK_BlockPointerToObjCPointerCast:
1448
0
  case CK_CPointerToObjCPointerCast:
1449
0
  case CK_ObjCObjectLValueCast:
1450
0
  case CK_IntToOCLSampler:
1451
0
  case CK_ZeroToOCLOpaqueType:
1452
    // FIXME: Check these.
1453
0
    return false;
1454
1455
0
  case CK_FixedPointCast:
1456
0
  case CK_FixedPointToBoolean:
1457
0
  case CK_FixedPointToFloating:
1458
0
  case CK_FixedPointToIntegral:
1459
0
  case CK_FloatingToFixedPoint:
1460
0
  case CK_IntegralToFixedPoint:
1461
    // FIXME: Do all fixed-point types represent zero as all 0 bits?
1462
0
    return false;
1463
1464
0
  case CK_AddressSpaceConversion:
1465
0
  case CK_BaseToDerived:
1466
0
  case CK_DerivedToBase:
1467
0
  case CK_Dynamic:
1468
18
  case CK_NullToPointer:
1469
18
  case CK_PointerToBoolean:
1470
    // FIXME: Preserves zeroes only if zero pointers and null pointers have the
1471
    // same representation in all involved address spaces.
1472
18
    return false;
1473
1474
0
  case CK_ARCConsumeObject:
1475
0
  case CK_ARCExtendBlockObject:
1476
0
  case CK_ARCProduceObject:
1477
0
  case CK_ARCReclaimReturnedObject:
1478
0
  case CK_CopyAndAutoreleaseBlockObject:
1479
2
  case CK_ArrayToPointerDecay:
1480
2
  case CK_FunctionToPointerDecay:
1481
2
  case CK_BuiltinFnToFnPtr:
1482
2
  case CK_Dependent:
1483
2
  case CK_LValueBitCast:
1484
173
  case CK_LValueToRValue:
1485
173
  case CK_LValueToRValueBitCast:
1486
173
  case CK_UncheckedDerivedToBase:
1487
173
    return false;
1488
568
  }
1489
0
  llvm_unreachable("Unhandled clang::CastKind enum");
1490
0
}
1491
1492
/// isSimpleZero - If emitting this value will obviously just cause a store of
1493
/// zero to memory, return true.  This can return false if uncertain, so it just
1494
/// handles simple cases.
1495
4.89k
static bool isSimpleZero(const Expr *E, CodeGenFunction &CGF) {
1496
4.89k
  E = E->IgnoreParens();
1497
5.27k
  while (auto *CE = dyn_cast<CastExpr>(E)) {
1498
568
    if (!castPreservesZero(CE))
1499
191
      break;
1500
377
    E = CE->getSubExpr()->IgnoreParens();
1501
377
  }
1502
1503
  // 0
1504
4.89k
  if (const IntegerLiteral *IL = dyn_cast<IntegerLiteral>(E))
1505
450
    return IL->getValue() == 0;
1506
  // +0.0
1507
4.44k
  if (const FloatingLiteral *FL = dyn_cast<FloatingLiteral>(E))
1508
84
    return FL->getValue().isPosZero();
1509
  // int()
1510
4.36k
  if ((isa<ImplicitValueInitExpr>(E) || 
isa<CXXScalarValueInitExpr>(E)4.17k
) &&
1511
4.36k
      
CGF.getTypes().isZeroInitializable(E->getType())185
)
1512
185
    return true;
1513
  // (int*)0 - Null pointer expressions.
1514
4.17k
  if (const CastExpr *ICE = dyn_cast<CastExpr>(E))
1515
191
    return ICE->getCastKind() == CK_NullToPointer &&
1516
191
           
CGF.getTypes().isPointerZeroInitializable(E->getType())18
&&
1517
191
           
!E->HasSideEffects(CGF.getContext())18
;
1518
  // '\0'
1519
3.98k
  if (const CharacterLiteral *CL = dyn_cast<CharacterLiteral>(E))
1520
1
    return CL->getValue() == 0;
1521
1522
  // Otherwise, hard case: conservatively return false.
1523
3.98k
  return false;
1524
3.98k
}
1525
1526
1527
void
1528
8.46k
AggExprEmitter::EmitInitializationToLValue(Expr *E, LValue LV) {
1529
8.46k
  QualType type = LV.getType();
1530
  // FIXME: Ignore result?
1531
  // FIXME: Are initializers affected by volatile?
1532
8.46k
  if (Dest.isZeroed() && 
isSimpleZero(E, CGF)198
) {
1533
    // Storing "i32 0" to a zero'd memory location is a noop.
1534
122
    return;
1535
8.33k
  } else if (isa<ImplicitValueInitExpr>(E) || 
isa<CXXScalarValueInitExpr>(E)8.22k
) {
1536
111
    return EmitNullInitializationToLValue(LV);
1537
8.22k
  } else if (isa<NoInitExpr>(E)) {
1538
    // Do nothing.
1539
14
    return;
1540
8.21k
  } else if (type->isReferenceType()) {
1541
2.41k
    RValue RV = CGF.EmitReferenceBindingToExpr(E);
1542
2.41k
    return CGF.EmitStoreThroughLValue(RV, LV);
1543
2.41k
  }
1544
1545
5.79k
  switch (CGF.getEvaluationKind(type)) {
1546
9
  case TEK_Complex:
1547
9
    CGF.EmitComplexExprIntoLValue(E, LV, /*isInit*/ true);
1548
9
    return;
1549
3.08k
  case TEK_Aggregate:
1550
3.08k
    CGF.EmitAggExpr(
1551
3.08k
        E, AggValueSlot::forLValue(LV, CGF, AggValueSlot::IsDestructed,
1552
3.08k
                                   AggValueSlot::DoesNotNeedGCBarriers,
1553
3.08k
                                   AggValueSlot::IsNotAliased,
1554
3.08k
                                   AggValueSlot::MayOverlap, Dest.isZeroed()));
1555
3.08k
    return;
1556
2.70k
  case TEK_Scalar:
1557
2.70k
    if (LV.isSimple()) {
1558
2.69k
      CGF.EmitScalarInit(E, /*D=*/nullptr, LV, /*Captured=*/false);
1559
2.69k
    } else {
1560
11
      CGF.EmitStoreThroughLValue(RValue::get(CGF.EmitScalarExpr(E)), LV);
1561
11
    }
1562
2.70k
    return;
1563
5.79k
  }
1564
0
  llvm_unreachable("bad evaluation kind");
1565
0
}
1566
1567
146
void AggExprEmitter::EmitNullInitializationToLValue(LValue lv) {
1568
146
  QualType type = lv.getType();
1569
1570
  // If the destination slot is already zeroed out before the aggregate is
1571
  // copied into it, we don't have to emit any zeros here.
1572
146
  if (Dest.isZeroed() && 
CGF.getTypes().isZeroInitializable(type)11
)
1573
11
    return;
1574
1575
135
  if (CGF.hasScalarEvaluationKind(type)) {
1576
    // For non-aggregates, we can store the appropriate null constant.
1577
111
    llvm::Value *null = CGF.CGM.EmitNullConstant(type);
1578
    // Note that the following is not equivalent to
1579
    // EmitStoreThroughBitfieldLValue for ARC types.
1580
111
    if (lv.isBitField()) {
1581
1
      CGF.EmitStoreThroughBitfieldLValue(RValue::get(null), lv);
1582
110
    } else {
1583
110
      assert(lv.isSimple());
1584
0
      CGF.EmitStoreOfScalar(null, lv, /* isInitialization */ true);
1585
110
    }
1586
111
  } else {
1587
    // There's a potential optimization opportunity in combining
1588
    // memsets; that would be easy for arrays, but relatively
1589
    // difficult for structures with the current code.
1590
24
    CGF.EmitNullInitialization(lv.getAddress(CGF), lv.getType());
1591
24
  }
1592
135
}
1593
1594
3.16k
void AggExprEmitter::VisitInitListExpr(InitListExpr *E) {
1595
#if 0
1596
  // FIXME: Assess perf here?  Figure out what cases are worth optimizing here
1597
  // (Length of globals? Chunks of zeroed-out space?).
1598
  //
1599
  // If we can, prefer a copy from a global; this is a lot less code for long
1600
  // globals, and it's easier for the current optimizers to analyze.
1601
  if (llvm::Constant* C = CGF.CGM.EmitConstantExpr(E, E->getType(), &CGF)) {
1602
    llvm::GlobalVariable* GV =
1603
    new llvm::GlobalVariable(CGF.CGM.getModule(), C->getType(), true,
1604
                             llvm::GlobalValue::InternalLinkage, C, "");
1605
    EmitFinalDestCopy(E->getType(), CGF.MakeAddrLValue(GV, E->getType()));
1606
    return;
1607
  }
1608
#endif
1609
3.16k
  if (E->hadArrayRangeDesignator())
1610
0
    CGF.ErrorUnsupported(E, "GNU array range designator extension");
1611
1612
3.16k
  if (E->isTransparent())
1613
10
    return Visit(E->getInit(0));
1614
1615
3.15k
  AggValueSlot Dest = EnsureSlot(E->getType());
1616
1617
3.15k
  LValue DestLV = CGF.MakeAddrLValue(Dest.getAddress(), E->getType());
1618
1619
  // Handle initialization of an array.
1620
3.15k
  if (E->getType()->isArrayType()) {
1621
1.66k
    auto AType = cast<llvm::ArrayType>(Dest.getAddress().getElementType());
1622
1.66k
    EmitArrayInit(Dest.getAddress(), AType, E->getType(), E);
1623
1.66k
    return;
1624
1.66k
  }
1625
1626
1.48k
  assert(E->getType()->isRecordType() && "Only support structs/unions here!");
1627
1628
  // Do struct initialization; this code just sets each individual member
1629
  // to the approprate value.  This makes bitfield support automatic;
1630
  // the disadvantage is that the generated code is more difficult for
1631
  // the optimizer, especially with bitfields.
1632
0
  unsigned NumInitElements = E->getNumInits();
1633
1.48k
  RecordDecl *record = E->getType()->castAs<RecordType>()->getDecl();
1634
1635
  // We'll need to enter cleanup scopes in case any of the element
1636
  // initializers throws an exception.
1637
1.48k
  SmallVector<EHScopeStack::stable_iterator, 16> cleanups;
1638
1.48k
  llvm::Instruction *cleanupDominator = nullptr;
1639
1.48k
  auto addCleanup = [&](const EHScopeStack::stable_iterator &cleanup) {
1640
16
    cleanups.push_back(cleanup);
1641
16
    if (!cleanupDominator) // create placeholder once needed
1642
8
      cleanupDominator = CGF.Builder.CreateAlignedLoad(
1643
8
          CGF.Int8Ty, llvm::Constant::getNullValue(CGF.Int8PtrTy),
1644
8
          CharUnits::One());
1645
16
  };
1646
1647
1.48k
  unsigned curInitIndex = 0;
1648
1649
  // Emit initialization of base classes.
1650
1.48k
  if (auto *CXXRD = dyn_cast<CXXRecordDecl>(record)) {
1651
1.04k
    assert(E->getNumInits() >= CXXRD->getNumBases() &&
1652
1.04k
           "missing initializer for base class");
1653
16
    for (auto &Base : CXXRD->bases()) {
1654
16
      assert(!Base.isVirtual() && "should not see vbases here");
1655
0
      auto *BaseRD = Base.getType()->getAsCXXRecordDecl();
1656
16
      Address V = CGF.GetAddressOfDirectBaseInCompleteClass(
1657
16
          Dest.getAddress(), CXXRD, BaseRD,
1658
16
          /*isBaseVirtual*/ false);
1659
16
      AggValueSlot AggSlot = AggValueSlot::forAddr(
1660
16
          V, Qualifiers(),
1661
16
          AggValueSlot::IsDestructed,
1662
16
          AggValueSlot::DoesNotNeedGCBarriers,
1663
16
          AggValueSlot::IsNotAliased,
1664
16
          CGF.getOverlapForBaseInit(CXXRD, BaseRD, Base.isVirtual()));
1665
16
      CGF.EmitAggExpr(E->getInit(curInitIndex++), AggSlot);
1666
1667
16
      if (QualType::DestructionKind dtorKind =
1668
16
              Base.getType().isDestructedType()) {
1669
8
        CGF.pushDestroy(dtorKind, V, Base.getType());
1670
8
        addCleanup(CGF.EHStack.stable_begin());
1671
8
      }
1672
16
    }
1673
1.04k
  }
1674
1675
  // Prepare a 'this' for CXXDefaultInitExprs.
1676
0
  CodeGenFunction::FieldConstructionScope FCS(CGF, Dest.getAddress());
1677
1678
1.48k
  if (record->isUnion()) {
1679
    // Only initialize one field of a union. The field itself is
1680
    // specified by the initializer list.
1681
67
    if (!E->getInitializedFieldInUnion()) {
1682
      // Empty union; we have nothing to do.
1683
1684
12
#ifndef NDEBUG
1685
      // Make sure that it's really an empty and not a failure of
1686
      // semantic analysis.
1687
12
      for (const auto *Field : record->fields())
1688
0
        assert(Field->isUnnamedBitfield() && "Only unnamed bitfields allowed");
1689
12
#endif
1690
12
      return;
1691
12
    }
1692
1693
    // FIXME: volatility
1694
55
    FieldDecl *Field = E->getInitializedFieldInUnion();
1695
1696
55
    LValue FieldLoc = CGF.EmitLValueForFieldInitialization(DestLV, Field);
1697
55
    if (NumInitElements) {
1698
      // Store the initializer into the field
1699
39
      EmitInitializationToLValue(E->getInit(0), FieldLoc);
1700
39
    } else {
1701
      // Default-initialize to null.
1702
16
      EmitNullInitializationToLValue(FieldLoc);
1703
16
    }
1704
1705
55
    return;
1706
67
  }
1707
1708
  // Here we iterate over the fields; this makes it simpler to both
1709
  // default-initialize fields and skip over unnamed fields.
1710
2.33k
  
for (const auto *field : record->fields())1.42k
{
1711
    // We're done once we hit the flexible array member.
1712
2.33k
    if (field->getType()->isIncompleteArrayType())
1713
0
      break;
1714
1715
    // Always skip anonymous bitfields.
1716
2.33k
    if (field->isUnnamedBitfield())
1717
24
      continue;
1718
1719
    // We're done if we reach the end of the explicit initializers, we
1720
    // have a zeroed object, and the rest of the fields are
1721
    // zero-initializable.
1722
2.31k
    if (curInitIndex == NumInitElements && 
Dest.isZeroed()0
&&
1723
2.31k
        
CGF.getTypes().isZeroInitializable(E->getType())0
)
1724
0
      break;
1725
1726
1727
2.31k
    LValue LV = CGF.EmitLValueForFieldInitialization(DestLV, field);
1728
    // We never generate write-barries for initialized fields.
1729
2.31k
    LV.setNonGC(true);
1730
1731
2.31k
    if (curInitIndex < NumInitElements) {
1732
      // Store the initializer into the field.
1733
2.31k
      EmitInitializationToLValue(E->getInit(curInitIndex++), LV);
1734
2.31k
    } else {
1735
      // We're out of initializers; default-initialize to null
1736
0
      EmitNullInitializationToLValue(LV);
1737
0
    }
1738
1739
    // Push a destructor if necessary.
1740
    // FIXME: if we have an array of structures, all explicitly
1741
    // initialized, we can end up pushing a linear number of cleanups.
1742
2.31k
    bool pushedCleanup = false;
1743
2.31k
    if (QualType::DestructionKind dtorKind
1744
2.31k
          = field->getType().isDestructedType()) {
1745
63
      assert(LV.isSimple());
1746
63
      if (CGF.needsEHCleanup(dtorKind)) {
1747
8
        CGF.pushDestroy(EHCleanup, LV.getAddress(CGF), field->getType(),
1748
8
                        CGF.getDestroyer(dtorKind), false);
1749
8
        addCleanup(CGF.EHStack.stable_begin());
1750
8
        pushedCleanup = true;
1751
8
      }
1752
63
    }
1753
1754
    // If the GEP didn't get used because of a dead zero init or something
1755
    // else, clean it up for -O0 builds and general tidiness.
1756
2.31k
    if (!pushedCleanup && 
LV.isSimple()2.30k
)
1757
2.29k
      if (llvm::GetElementPtrInst *GEP =
1758
2.29k
              dyn_cast<llvm::GetElementPtrInst>(LV.getPointer(CGF)))
1759
2.20k
        if (GEP->use_empty())
1760
144
          GEP->eraseFromParent();
1761
2.31k
  }
1762
1763
  // Deactivate all the partial cleanups in reverse order, which
1764
  // generally means popping them.
1765
1.42k
  assert((cleanupDominator || cleanups.empty()) &&
1766
1.42k
         "Missing cleanupDominator before deactivating cleanup blocks");
1767
1.43k
  for (unsigned i = cleanups.size(); i != 0; 
--i16
)
1768
16
    CGF.DeactivateCleanupBlock(cleanups[i-1], cleanupDominator);
1769
1770
  // Destroy the placeholder if we made one.
1771
1.42k
  if (cleanupDominator)
1772
8
    cleanupDominator->eraseFromParent();
1773
1.42k
}
1774
1775
void AggExprEmitter::VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E,
1776
30
                                            llvm::Value *outerBegin) {
1777
  // Emit the common subexpression.
1778
30
  CodeGenFunction::OpaqueValueMapping binding(CGF, E->getCommonExpr());
1779
1780
30
  Address destPtr = EnsureSlot(E->getType()).getAddress();
1781
30
  uint64_t numElements = E->getArraySize().getZExtValue();
1782
1783
30
  if (!numElements)
1784
0
    return;
1785
1786
  // destPtr is an array*. Construct an elementType* by drilling down a level.
1787
30
  llvm::Value *zero = llvm::ConstantInt::get(CGF.SizeTy, 0);
1788
30
  llvm::Value *indices[] = {zero, zero};
1789
30
  llvm::Value *begin = Builder.CreateInBoundsGEP(
1790
30
      destPtr.getElementType(), destPtr.getPointer(), indices,
1791
30
      "arrayinit.begin");
1792
1793
  // Prepare to special-case multidimensional array initialization: we avoid
1794
  // emitting multiple destructor loops in that case.
1795
30
  if (!outerBegin)
1796
23
    outerBegin = begin;
1797
30
  ArrayInitLoopExpr *InnerLoop = dyn_cast<ArrayInitLoopExpr>(E->getSubExpr());
1798
1799
30
  QualType elementType =
1800
30
      CGF.getContext().getAsArrayType(E->getType())->getElementType();
1801
30
  CharUnits elementSize = CGF.getContext().getTypeSizeInChars(elementType);
1802
30
  CharUnits elementAlign =
1803
30
      destPtr.getAlignment().alignmentOfArrayElement(elementSize);
1804
30
  llvm::Type *llvmElementType = CGF.ConvertTypeForMem(elementType);
1805
1806
30
  llvm::BasicBlock *entryBB = Builder.GetInsertBlock();
1807
30
  llvm::BasicBlock *bodyBB = CGF.createBasicBlock("arrayinit.body");
1808
1809
  // Jump into the body.
1810
30
  CGF.EmitBlock(bodyBB);
1811
30
  llvm::PHINode *index =
1812
30
      Builder.CreatePHI(zero->getType(), 2, "arrayinit.index");
1813
30
  index->addIncoming(zero, entryBB);
1814
30
  llvm::Value *element =
1815
30
      Builder.CreateInBoundsGEP(llvmElementType, begin, index);
1816
1817
  // Prepare for a cleanup.
1818
30
  QualType::DestructionKind dtorKind = elementType.isDestructedType();
1819
30
  EHScopeStack::stable_iterator cleanup;
1820
30
  if (CGF.needsEHCleanup(dtorKind) && 
!InnerLoop7
) {
1821
6
    if (outerBegin->getType() != element->getType())
1822
1
      outerBegin = Builder.CreateBitCast(outerBegin, element->getType());
1823
6
    CGF.pushRegularPartialArrayCleanup(outerBegin, element, elementType,
1824
6
                                       elementAlign,
1825
6
                                       CGF.getDestroyer(dtorKind));
1826
6
    cleanup = CGF.EHStack.stable_begin();
1827
24
  } else {
1828
24
    dtorKind = QualType::DK_none;
1829
24
  }
1830
1831
  // Emit the actual filler expression.
1832
30
  {
1833
    // Temporaries created in an array initialization loop are destroyed
1834
    // at the end of each iteration.
1835
30
    CodeGenFunction::RunCleanupsScope CleanupsScope(CGF);
1836
30
    CodeGenFunction::ArrayInitLoopExprScope Scope(CGF, index);
1837
30
    LValue elementLV =
1838
30
        CGF.MakeAddrLValue(Address(element, elementAlign), elementType);
1839
1840
30
    if (InnerLoop) {
1841
      // If the subexpression is an ArrayInitLoopExpr, share its cleanup.
1842
7
      auto elementSlot = AggValueSlot::forLValue(
1843
7
          elementLV, CGF, AggValueSlot::IsDestructed,
1844
7
          AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased,
1845
7
          AggValueSlot::DoesNotOverlap);
1846
7
      AggExprEmitter(CGF, elementSlot, false)
1847
7
          .VisitArrayInitLoopExpr(InnerLoop, outerBegin);
1848
7
    } else
1849
23
      EmitInitializationToLValue(E->getSubExpr(), elementLV);
1850
30
  }
1851
1852
  // Move on to the next element.
1853
30
  llvm::Value *nextIndex = Builder.CreateNUWAdd(
1854
30
      index, llvm::ConstantInt::get(CGF.SizeTy, 1), "arrayinit.next");
1855
30
  index->addIncoming(nextIndex, Builder.GetInsertBlock());
1856
1857
  // Leave the loop if we're done.
1858
30
  llvm::Value *done = Builder.CreateICmpEQ(
1859
30
      nextIndex, llvm::ConstantInt::get(CGF.SizeTy, numElements),
1860
30
      "arrayinit.done");
1861
30
  llvm::BasicBlock *endBB = CGF.createBasicBlock("arrayinit.end");
1862
30
  Builder.CreateCondBr(done, endBB, bodyBB);
1863
1864
30
  CGF.EmitBlock(endBB);
1865
1866
  // Leave the partial-array cleanup if we entered one.
1867
30
  if (dtorKind)
1868
6
    CGF.DeactivateCleanupBlock(cleanup, index);
1869
30
}
1870
1871
8
void AggExprEmitter::VisitDesignatedInitUpdateExpr(DesignatedInitUpdateExpr *E) {
1872
8
  AggValueSlot Dest = EnsureSlot(E->getType());
1873
1874
8
  LValue DestLV = CGF.MakeAddrLValue(Dest.getAddress(), E->getType());
1875
8
  EmitInitializationToLValue(E->getBase(), DestLV);
1876
8
  VisitInitListExpr(E->getUpdater());
1877
8
}
1878
1879
//===----------------------------------------------------------------------===//
1880
//                        Entry Points into this File
1881
//===----------------------------------------------------------------------===//
1882
1883
/// GetNumNonZeroBytesInInit - Get an approximate count of the number of
1884
/// non-zero bytes that will be stored when outputting the initializer for the
1885
/// specified initializer expression.
1886
4.69k
static CharUnits GetNumNonZeroBytesInInit(const Expr *E, CodeGenFunction &CGF) {
1887
4.69k
  if (auto *MTE = dyn_cast<MaterializeTemporaryExpr>(E))
1888
71
    E = MTE->getSubExpr();
1889
4.69k
  E = E->IgnoreParenNoopCasts(CGF.getContext());
1890
1891
  // 0 and 0.0 won't require any non-zero stores!
1892
4.69k
  if (isSimpleZero(E, CGF)) 
return CharUnits::Zero()188
;
1893
1894
  // If this is an initlist expr, sum up the size of sizes of the (present)
1895
  // elements.  If this is something weird, assume the whole thing is non-zero.
1896
4.50k
  const InitListExpr *ILE = dyn_cast<InitListExpr>(E);
1897
4.51k
  while (ILE && 
ILE->isTransparent()251
)
1898
6
    ILE = dyn_cast<InitListExpr>(ILE->getInit(0));
1899
4.50k
  if (!ILE || 
!CGF.getTypes().isZeroInitializable(ILE->getType())245
)
1900
4.26k
    return CGF.getContext().getTypeSizeInChars(E->getType());
1901
1902
  // InitListExprs for structs have to be handled carefully.  If there are
1903
  // reference members, we need to consider the size of the reference, not the
1904
  // referencee.  InitListExprs for unions and arrays can't have references.
1905
245
  if (const RecordType *RT = E->getType()->getAs<RecordType>()) {
1906
130
    if (!RT->isUnionType()) {
1907
127
      RecordDecl *SD = RT->getDecl();
1908
127
      CharUnits NumNonZeroBytes = CharUnits::Zero();
1909
1910
127
      unsigned ILEElement = 0;
1911
127
      if (auto *CXXRD = dyn_cast<CXXRecordDecl>(SD))
1912
87
        while (ILEElement != CXXRD->getNumBases())
1913
0
          NumNonZeroBytes +=
1914
0
              GetNumNonZeroBytesInInit(ILE->getInit(ILEElement++), CGF);
1915
484
      for (const auto *Field : SD->fields()) {
1916
        // We're done once we hit the flexible array member or run out of
1917
        // InitListExpr elements.
1918
484
        if (Field->getType()->isIncompleteArrayType() ||
1919
484
            ILEElement == ILE->getNumInits())
1920
0
          break;
1921
484
        if (Field->isUnnamedBitfield())
1922
0
          continue;
1923
1924
484
        const Expr *E = ILE->getInit(ILEElement++);
1925
1926
        // Reference values are always non-null and have the width of a pointer.
1927
484
        if (Field->getType()->isReferenceType())
1928
4
          NumNonZeroBytes += CGF.getContext().toCharUnitsFromBits(
1929
4
              CGF.getTarget().getPointerWidth(0));
1930
480
        else
1931
480
          NumNonZeroBytes += GetNumNonZeroBytesInInit(E, CGF);
1932
484
      }
1933
1934
127
      return NumNonZeroBytes;
1935
127
    }
1936
130
  }
1937
1938
  // FIXME: This overestimates the number of non-zero bytes for bit-fields.
1939
118
  CharUnits NumNonZeroBytes = CharUnits::Zero();
1940
497
  for (unsigned i = 0, e = ILE->getNumInits(); i != e; 
++i379
)
1941
379
    NumNonZeroBytes += GetNumNonZeroBytesInInit(ILE->getInit(i), CGF);
1942
118
  return NumNonZeroBytes;
1943
245
}
1944
1945
/// CheckAggExprForMemSetUse - If the initializer is large and has a lot of
1946
/// zeros in it, emit a memset and avoid storing the individual zeros.
1947
///
1948
static void CheckAggExprForMemSetUse(AggValueSlot &Slot, const Expr *E,
1949
83.6k
                                     CodeGenFunction &CGF) {
1950
  // If the slot is already known to be zeroed, nothing to do.  Don't mess with
1951
  // volatile stores.
1952
83.6k
  if (Slot.isZeroed() || 
Slot.isVolatile()83.5k
||
!Slot.getAddress().isValid()83.5k
)
1953
1.57k
    return;
1954
1955
  // C++ objects with a user-declared constructor don't need zero'ing.
1956
82.0k
  if (CGF.getLangOpts().CPlusPlus)
1957
76.9k
    if (const RecordType *RT = CGF.getContext()
1958
76.9k
                       .getBaseElementType(E->getType())->getAs<RecordType>()) {
1959
76.7k
      const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
1960
76.7k
      if (RD->hasUserDeclaredConstructor())
1961
54.7k
        return;
1962
76.7k
    }
1963
1964
  // If the type is 16-bytes or smaller, prefer individual stores over memset.
1965
27.2k
  CharUnits Size = Slot.getPreferredSize(CGF.getContext(), E->getType());
1966
27.2k
  if (Size <= CharUnits::fromQuantity(16))
1967
23.4k
    return;
1968
1969
  // Check to see if over 3/4 of the initializer are known to be zero.  If so,
1970
  // we prefer to emit memset + individual stores for the rest.
1971
3.83k
  CharUnits NumNonZeroBytes = GetNumNonZeroBytesInInit(E, CGF);
1972
3.83k
  if (NumNonZeroBytes*4 > Size)
1973
3.76k
    return;
1974
1975
  // Okay, it seems like a good idea to use an initial memset, emit the call.
1976
69
  llvm::Constant *SizeVal = CGF.Builder.getInt64(Size.getQuantity());
1977
1978
69
  Address Loc = Slot.getAddress();
1979
69
  Loc = CGF.Builder.CreateElementBitCast(Loc, CGF.Int8Ty);
1980
69
  CGF.Builder.CreateMemSet(Loc, CGF.Builder.getInt8(0), SizeVal, false);
1981
1982
  // Tell the AggExprEmitter that the slot is known zero.
1983
69
  Slot.setZeroed();
1984
69
}
1985
1986
1987
1988
1989
/// EmitAggExpr - Emit the computation of the specified expression of aggregate
1990
/// type.  The result is computed into DestPtr.  Note that if DestPtr is null,
1991
/// the value of the aggregate expression is not needed.  If VolatileDest is
1992
/// true, DestPtr cannot be 0.
1993
83.6k
void CodeGenFunction::EmitAggExpr(const Expr *E, AggValueSlot Slot) {
1994
83.6k
  assert(E && hasAggregateEvaluationKind(E->getType()) &&
1995
83.6k
         "Invalid aggregate expression to emit");
1996
0
  assert((Slot.getAddress().isValid() || Slot.isIgnored()) &&
1997
83.6k
         "slot has bits but no address");
1998
1999
  // Optimize the slot if possible.
2000
0
  CheckAggExprForMemSetUse(Slot, E, *this);
2001
2002
83.6k
  AggExprEmitter(*this, Slot, Slot.isIgnored()).Visit(const_cast<Expr*>(E));
2003
83.6k
}
2004
2005
84
LValue CodeGenFunction::EmitAggExprToLValue(const Expr *E) {
2006
84
  assert(hasAggregateEvaluationKind(E->getType()) && "Invalid argument!");
2007
0
  Address Temp = CreateMemTemp(E->getType());
2008
84
  LValue LV = MakeAddrLValue(Temp, E->getType());
2009
84
  EmitAggExpr(E, AggValueSlot::forLValue(
2010
84
                     LV, *this, AggValueSlot::IsNotDestructed,
2011
84
                     AggValueSlot::DoesNotNeedGCBarriers,
2012
84
                     AggValueSlot::IsNotAliased, AggValueSlot::DoesNotOverlap));
2013
84
  return LV;
2014
84
}
2015
2016
AggValueSlot::Overlap_t
2017
4.79k
CodeGenFunction::getOverlapForFieldInit(const FieldDecl *FD) {
2018
4.79k
  if (!FD->hasAttr<NoUniqueAddressAttr>() || 
!FD->getType()->isRecordType()3
)
2019
4.79k
    return AggValueSlot::DoesNotOverlap;
2020
2021
  // If the field lies entirely within the enclosing class's nvsize, its tail
2022
  // padding cannot overlap any already-initialized object. (The only subobjects
2023
  // with greater addresses that might already be initialized are vbases.)
2024
3
  const RecordDecl *ClassRD = FD->getParent();
2025
3
  const ASTRecordLayout &Layout = getContext().getASTRecordLayout(ClassRD);
2026
3
  if (Layout.getFieldOffset(FD->getFieldIndex()) +
2027
3
          getContext().getTypeSize(FD->getType()) <=
2028
3
      (uint64_t)getContext().toBits(Layout.getNonVirtualSize()))
2029
1
    return AggValueSlot::DoesNotOverlap;
2030
2031
  // The tail padding may contain values we need to preserve.
2032
2
  return AggValueSlot::MayOverlap;
2033
3
}
2034
2035
AggValueSlot::Overlap_t CodeGenFunction::getOverlapForBaseInit(
2036
10.7k
    const CXXRecordDecl *RD, const CXXRecordDecl *BaseRD, bool IsVirtual) {
2037
  // If the most-derived object is a field declared with [[no_unique_address]],
2038
  // the tail padding of any virtual base could be reused for other subobjects
2039
  // of that field's class.
2040
10.7k
  if (IsVirtual)
2041
781
    return AggValueSlot::MayOverlap;
2042
2043
  // If the base class is laid out entirely within the nvsize of the derived
2044
  // class, its tail padding cannot yet be initialized, so we can issue
2045
  // stores at the full width of the base class.
2046
9.94k
  const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
2047
9.94k
  if (Layout.getBaseClassOffset(BaseRD) +
2048
9.94k
          getContext().getASTRecordLayout(BaseRD).getSize() <=
2049
9.94k
      Layout.getNonVirtualSize())
2050
9.64k
    return AggValueSlot::DoesNotOverlap;
2051
2052
  // The tail padding may contain values we need to preserve.
2053
294
  return AggValueSlot::MayOverlap;
2054
9.94k
}
2055
2056
void CodeGenFunction::EmitAggregateCopy(LValue Dest, LValue Src, QualType Ty,
2057
                                        AggValueSlot::Overlap_t MayOverlap,
2058
13.8k
                                        bool isVolatile) {
2059
13.8k
  assert(!Ty->isAnyComplexType() && "Shouldn't happen for complex");
2060
2061
0
  Address DestPtr = Dest.getAddress(*this);
2062
13.8k
  Address SrcPtr = Src.getAddress(*this);
2063
2064
13.8k
  if (getLangOpts().CPlusPlus) {
2065
11.0k
    if (const RecordType *RT = Ty->getAs<RecordType>()) {
2066
9.50k
      CXXRecordDecl *Record = cast<CXXRecordDecl>(RT->getDecl());
2067
9.50k
      assert((Record->hasTrivialCopyConstructor() ||
2068
9.50k
              Record->hasTrivialCopyAssignment() ||
2069
9.50k
              Record->hasTrivialMoveConstructor() ||
2070
9.50k
              Record->hasTrivialMoveAssignment() ||
2071
9.50k
              Record->hasAttr<TrivialABIAttr>() || Record->isUnion()) &&
2072
9.50k
             "Trying to aggregate-copy a type without a trivial copy/move "
2073
9.50k
             "constructor or assignment operator");
2074
      // Ignore empty classes in C++.
2075
9.50k
      if (Record->isEmpty())
2076
3.02k
        return;
2077
9.50k
    }
2078
11.0k
  }
2079
2080
10.7k
  if (getLangOpts().CUDAIsDevice) {
2081
0
    if (Ty->isCUDADeviceBuiltinSurfaceType()) {
2082
0
      if (getTargetHooks().emitCUDADeviceBuiltinSurfaceDeviceCopy(*this, Dest,
2083
0
                                                                  Src))
2084
0
        return;
2085
0
    } else if (Ty->isCUDADeviceBuiltinTextureType()) {
2086
0
      if (getTargetHooks().emitCUDADeviceBuiltinTextureDeviceCopy(*this, Dest,
2087
0
                                                                  Src))
2088
0
        return;
2089
0
    }
2090
0
  }
2091
2092
  // Aggregate assignment turns into llvm.memcpy.  This is almost valid per
2093
  // C99 6.5.16.1p3, which states "If the value being stored in an object is
2094
  // read from another object that overlaps in anyway the storage of the first
2095
  // object, then the overlap shall be exact and the two objects shall have
2096
  // qualified or unqualified versions of a compatible type."
2097
  //
2098
  // memcpy is not defined if the source and destination pointers are exactly
2099
  // equal, but other compilers do this optimization, and almost every memcpy
2100
  // implementation handles this case safely.  If there is a libc that does not
2101
  // safely handle this, we can add a target hook.
2102
2103
  // Get data size info for this aggregate. Don't copy the tail padding if this
2104
  // might be a potentially-overlapping subobject, since the tail padding might
2105
  // be occupied by a different object. Otherwise, copying it is fine.
2106
10.7k
  TypeInfoChars TypeInfo;
2107
10.7k
  if (MayOverlap)
2108
4.71k
    TypeInfo = getContext().getTypeInfoDataSizeInChars(Ty);
2109
6.07k
  else
2110
6.07k
    TypeInfo = getContext().getTypeInfoInChars(Ty);
2111
2112
10.7k
  llvm::Value *SizeVal = nullptr;
2113
10.7k
  if (TypeInfo.Width.isZero()) {
2114
    // But note that getTypeInfo returns 0 for a VLA.
2115
138
    if (auto *VAT = dyn_cast_or_null<VariableArrayType>(
2116
138
            getContext().getAsArrayType(Ty))) {
2117
84
      QualType BaseEltTy;
2118
84
      SizeVal = emitArrayLength(VAT, BaseEltTy, DestPtr);
2119
84
      TypeInfo = getContext().getTypeInfoInChars(BaseEltTy);
2120
84
      assert(!TypeInfo.Width.isZero());
2121
0
      SizeVal = Builder.CreateNUWMul(
2122
84
          SizeVal,
2123
84
          llvm::ConstantInt::get(SizeTy, TypeInfo.Width.getQuantity()));
2124
84
    }
2125
138
  }
2126
10.7k
  if (!SizeVal) {
2127
10.6k
    SizeVal = llvm::ConstantInt::get(SizeTy, TypeInfo.Width.getQuantity());
2128
10.6k
  }
2129
2130
  // FIXME: If we have a volatile struct, the optimizer can remove what might
2131
  // appear to be `extra' memory ops:
2132
  //
2133
  // volatile struct { int i; } a, b;
2134
  //
2135
  // int main() {
2136
  //   a = b;
2137
  //   a = b;
2138
  // }
2139
  //
2140
  // we need to use a different call here.  We use isVolatile to indicate when
2141
  // either the source or the destination is volatile.
2142
2143
10.7k
  DestPtr = Builder.CreateElementBitCast(DestPtr, Int8Ty);
2144
10.7k
  SrcPtr = Builder.CreateElementBitCast(SrcPtr, Int8Ty);
2145
2146
  // Don't do any of the memmove_collectable tests if GC isn't set.
2147
10.7k
  if (CGM.getLangOpts().getGC() == LangOptions::NonGC) {
2148
    // fall through
2149
10.7k
  } else 
if (const RecordType *30
RecordTy30
= Ty->getAs<RecordType>()) {
2150
28
    RecordDecl *Record = RecordTy->getDecl();
2151
28
    if (Record->hasObjectMember()) {
2152
23
      CGM.getObjCRuntime().EmitGCMemmoveCollectable(*this, DestPtr, SrcPtr,
2153
23
                                                    SizeVal);
2154
23
      return;
2155
23
    }
2156
28
  } else 
if (2
Ty->isArrayType()2
) {
2157
2
    QualType BaseType = getContext().getBaseElementType(Ty);
2158
2
    if (const RecordType *RecordTy = BaseType->getAs<RecordType>()) {
2159
1
      if (RecordTy->getDecl()->hasObjectMember()) {
2160
1
        CGM.getObjCRuntime().EmitGCMemmoveCollectable(*this, DestPtr, SrcPtr,
2161
1
                                                      SizeVal);
2162
1
        return;
2163
1
      }
2164
1
    }
2165
2
  }
2166
2167
10.7k
  auto Inst = Builder.CreateMemCpy(DestPtr, SrcPtr, SizeVal, isVolatile);
2168
2169
  // Determine the metadata to describe the position of any padding in this
2170
  // memcpy, as well as the TBAA tags for the members of the struct, in case
2171
  // the optimizer wishes to expand it in to scalar memory operations.
2172
10.7k
  if (llvm::MDNode *TBAAStructTag = CGM.getTBAAStructInfo(Ty))
2173
283
    Inst->setMetadata(llvm::LLVMContext::MD_tbaa_struct, TBAAStructTag);
2174
2175
10.7k
  if (CGM.getCodeGenOpts().NewStructPathTBAA) {
2176
7
    TBAAAccessInfo TBAAInfo = CGM.mergeTBAAInfoForMemoryTransfer(
2177
7
        Dest.getTBAAInfo(), Src.getTBAAInfo());
2178
7
    CGM.DecorateInstructionWithTBAA(Inst, TBAAInfo);
2179
7
  }
2180
10.7k
}