1//===--- CGExprAgg.cpp - Emit LLVM Code from Aggregate Expressions --------===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This contains code to emit Aggregate Expr nodes as LLVM code.
11//
12//===----------------------------------------------------------------------===//
13
14#include "CodeGenFunction.h"
15#include "CodeGenModule.h"
16#include "clang/AST/ASTContext.h"
17#include "clang/AST/DeclCXX.h"
18#include "clang/AST/StmtVisitor.h"
19#include "llvm/Constants.h"
20#include "llvm/Function.h"
21#include "llvm/GlobalVariable.h"
22#include "llvm/Support/Compiler.h"
23#include "llvm/Intrinsics.h"
24using namespace clang;
25using namespace CodeGen;
26
27//===----------------------------------------------------------------------===//
28// Aggregate Expression Emitter
29//===----------------------------------------------------------------------===//
30
31namespace {
32class VISIBILITY_HIDDEN AggExprEmitter : public StmtVisitor<AggExprEmitter> {
33 CodeGenFunction &CGF;
34 CGBuilderTy &Builder;
35 llvm::Value *DestPtr;
36 bool VolatileDest;
37 bool IgnoreResult;
38
39public:
40 AggExprEmitter(CodeGenFunction &cgf, llvm::Value *destPtr, bool v,
41 bool ignore)
42 : CGF(cgf), Builder(CGF.Builder),
43 DestPtr(destPtr), VolatileDest(v), IgnoreResult(ignore) {
44 }
45
46 //===--------------------------------------------------------------------===//
47 // Utilities
48 //===--------------------------------------------------------------------===//
49
50 /// EmitAggLoadOfLValue - Given an expression with aggregate type that
51 /// represents a value lvalue, this method emits the address of the lvalue,
52 /// then loads the result into DestPtr.
53 void EmitAggLoadOfLValue(const Expr *E);
54
55 /// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
56 void EmitFinalDestCopy(const Expr *E, LValue Src, bool Ignore = false);
57 void EmitFinalDestCopy(const Expr *E, RValue Src, bool Ignore = false);
58
59 //===--------------------------------------------------------------------===//
60 // Visitor Methods
61 //===--------------------------------------------------------------------===//
62
63 void VisitStmt(Stmt *S) {
64 CGF.ErrorUnsupported(S, "aggregate expression");
65 }
66 void VisitParenExpr(ParenExpr *PE) { Visit(PE->getSubExpr()); }
67 void VisitUnaryExtension(UnaryOperator *E) { Visit(E->getSubExpr()); }
68
69 // l-values.
70 void VisitDeclRefExpr(DeclRefExpr *DRE) { EmitAggLoadOfLValue(DRE); }
71 void VisitMemberExpr(MemberExpr *ME) { EmitAggLoadOfLValue(ME); }
72 void VisitUnaryDeref(UnaryOperator *E) { EmitAggLoadOfLValue(E); }
73 void VisitStringLiteral(StringLiteral *E) { EmitAggLoadOfLValue(E); }
74 void VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
75 EmitAggLoadOfLValue(E);
76 }
77 void VisitArraySubscriptExpr(ArraySubscriptExpr *E) {
78 EmitAggLoadOfLValue(E);
79 }
80 void VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) {
81 EmitAggLoadOfLValue(E);
82 }
83 void VisitPredefinedExpr(const PredefinedExpr *E) {
84 EmitAggLoadOfLValue(E);
85 }
86
87 // Operators.
88 void VisitCStyleCastExpr(CStyleCastExpr *E);
89 void VisitImplicitCastExpr(ImplicitCastExpr *E);
90 void VisitCallExpr(const CallExpr *E);
91 void VisitStmtExpr(const StmtExpr *E);
92 void VisitBinaryOperator(const BinaryOperator *BO);
93 void VisitBinAssign(const BinaryOperator *E);
94 void VisitBinComma(const BinaryOperator *E);
95
96 void VisitObjCMessageExpr(ObjCMessageExpr *E);
97 void VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
98 EmitAggLoadOfLValue(E);
99 }
100 void VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E);
101 void VisitObjCKVCRefExpr(ObjCKVCRefExpr *E);
102
103 void VisitConditionalOperator(const ConditionalOperator *CO);
104 void VisitInitListExpr(InitListExpr *E);
105 void VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
106 Visit(DAE->getExpr());
107 }
108 void VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E);
109 void VisitCXXConstructExpr(const CXXConstructExpr *E);
110 void VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E);
111
112 void VisitVAArgExpr(VAArgExpr *E);
113
114 void EmitInitializationToLValue(Expr *E, LValue Address);
115 void EmitNullInitializationToLValue(LValue Address, QualType T);
116 // case Expr::ChooseExprClass:
117
118};
119} // end anonymous namespace.
120
121//===----------------------------------------------------------------------===//
122// Utilities
123//===----------------------------------------------------------------------===//
124
125/// EmitAggLoadOfLValue - Given an expression with aggregate type that
126/// represents a value lvalue, this method emits the address of the lvalue,
127/// then loads the result into DestPtr.
128void AggExprEmitter::EmitAggLoadOfLValue(const Expr *E) {
129 LValue LV = CGF.EmitLValue(E);
130 EmitFinalDestCopy(E, LV);
131}
132
133/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
134void AggExprEmitter::EmitFinalDestCopy(const Expr *E, RValue Src, bool Ignore) {
135 assert(Src.isAggregate() && "value must be aggregate value!");
136
137 // If the result is ignored, don't copy from the value.
138 if (DestPtr == 0) {
139 if (!Src.isVolatileQualified() || (IgnoreResult && Ignore))
140 return;
141 // If the source is volatile, we must read from it; to do that, we need
142 // some place to put it.
143 DestPtr = CGF.CreateTempAlloca(CGF.ConvertType(E->getType()), "agg.tmp");
144 }
145
146 // If the result of the assignment is used, copy the LHS there also.
147 // FIXME: Pass VolatileDest as well. I think we also need to merge volatile
148 // from the source as well, as we can't eliminate it if either operand
149 // is volatile, unless copy has volatile for both source and destination..
150 CGF.EmitAggregateCopy(DestPtr, Src.getAggregateAddr(), E->getType(),
151 VolatileDest|Src.isVolatileQualified());
152}
153
154/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
155void AggExprEmitter::EmitFinalDestCopy(const Expr *E, LValue Src, bool Ignore) {
156 assert(Src.isSimple() && "Can't have aggregate bitfield, vector, etc");
157
158 EmitFinalDestCopy(E, RValue::getAggregate(Src.getAddress(),
159 Src.isVolatileQualified()),
160 Ignore);
161}
162
163//===----------------------------------------------------------------------===//
164// Visitor Methods
165//===----------------------------------------------------------------------===//
166
167void AggExprEmitter::VisitCStyleCastExpr(CStyleCastExpr *E) {
168 // GCC union extension
| 1//===--- CGExprAgg.cpp - Emit LLVM Code from Aggregate Expressions --------===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This contains code to emit Aggregate Expr nodes as LLVM code.
11//
12//===----------------------------------------------------------------------===//
13
14#include "CodeGenFunction.h"
15#include "CodeGenModule.h"
16#include "clang/AST/ASTContext.h"
17#include "clang/AST/DeclCXX.h"
18#include "clang/AST/StmtVisitor.h"
19#include "llvm/Constants.h"
20#include "llvm/Function.h"
21#include "llvm/GlobalVariable.h"
22#include "llvm/Support/Compiler.h"
23#include "llvm/Intrinsics.h"
24using namespace clang;
25using namespace CodeGen;
26
27//===----------------------------------------------------------------------===//
28// Aggregate Expression Emitter
29//===----------------------------------------------------------------------===//
30
31namespace {
32class VISIBILITY_HIDDEN AggExprEmitter : public StmtVisitor<AggExprEmitter> {
33 CodeGenFunction &CGF;
34 CGBuilderTy &Builder;
35 llvm::Value *DestPtr;
36 bool VolatileDest;
37 bool IgnoreResult;
38
39public:
40 AggExprEmitter(CodeGenFunction &cgf, llvm::Value *destPtr, bool v,
41 bool ignore)
42 : CGF(cgf), Builder(CGF.Builder),
43 DestPtr(destPtr), VolatileDest(v), IgnoreResult(ignore) {
44 }
45
46 //===--------------------------------------------------------------------===//
47 // Utilities
48 //===--------------------------------------------------------------------===//
49
50 /// EmitAggLoadOfLValue - Given an expression with aggregate type that
51 /// represents a value lvalue, this method emits the address of the lvalue,
52 /// then loads the result into DestPtr.
53 void EmitAggLoadOfLValue(const Expr *E);
54
55 /// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
56 void EmitFinalDestCopy(const Expr *E, LValue Src, bool Ignore = false);
57 void EmitFinalDestCopy(const Expr *E, RValue Src, bool Ignore = false);
58
59 //===--------------------------------------------------------------------===//
60 // Visitor Methods
61 //===--------------------------------------------------------------------===//
62
63 void VisitStmt(Stmt *S) {
64 CGF.ErrorUnsupported(S, "aggregate expression");
65 }
66 void VisitParenExpr(ParenExpr *PE) { Visit(PE->getSubExpr()); }
67 void VisitUnaryExtension(UnaryOperator *E) { Visit(E->getSubExpr()); }
68
69 // l-values.
70 void VisitDeclRefExpr(DeclRefExpr *DRE) { EmitAggLoadOfLValue(DRE); }
71 void VisitMemberExpr(MemberExpr *ME) { EmitAggLoadOfLValue(ME); }
72 void VisitUnaryDeref(UnaryOperator *E) { EmitAggLoadOfLValue(E); }
73 void VisitStringLiteral(StringLiteral *E) { EmitAggLoadOfLValue(E); }
74 void VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
75 EmitAggLoadOfLValue(E);
76 }
77 void VisitArraySubscriptExpr(ArraySubscriptExpr *E) {
78 EmitAggLoadOfLValue(E);
79 }
80 void VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) {
81 EmitAggLoadOfLValue(E);
82 }
83 void VisitPredefinedExpr(const PredefinedExpr *E) {
84 EmitAggLoadOfLValue(E);
85 }
86
87 // Operators.
88 void VisitCStyleCastExpr(CStyleCastExpr *E);
89 void VisitImplicitCastExpr(ImplicitCastExpr *E);
90 void VisitCallExpr(const CallExpr *E);
91 void VisitStmtExpr(const StmtExpr *E);
92 void VisitBinaryOperator(const BinaryOperator *BO);
93 void VisitBinAssign(const BinaryOperator *E);
94 void VisitBinComma(const BinaryOperator *E);
95
96 void VisitObjCMessageExpr(ObjCMessageExpr *E);
97 void VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
98 EmitAggLoadOfLValue(E);
99 }
100 void VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E);
101 void VisitObjCKVCRefExpr(ObjCKVCRefExpr *E);
102
103 void VisitConditionalOperator(const ConditionalOperator *CO);
104 void VisitInitListExpr(InitListExpr *E);
105 void VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
106 Visit(DAE->getExpr());
107 }
108 void VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E);
109 void VisitCXXConstructExpr(const CXXConstructExpr *E);
110 void VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E);
111
112 void VisitVAArgExpr(VAArgExpr *E);
113
114 void EmitInitializationToLValue(Expr *E, LValue Address);
115 void EmitNullInitializationToLValue(LValue Address, QualType T);
116 // case Expr::ChooseExprClass:
117
118};
119} // end anonymous namespace.
120
121//===----------------------------------------------------------------------===//
122// Utilities
123//===----------------------------------------------------------------------===//
124
125/// EmitAggLoadOfLValue - Given an expression with aggregate type that
126/// represents a value lvalue, this method emits the address of the lvalue,
127/// then loads the result into DestPtr.
128void AggExprEmitter::EmitAggLoadOfLValue(const Expr *E) {
129 LValue LV = CGF.EmitLValue(E);
130 EmitFinalDestCopy(E, LV);
131}
132
133/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
134void AggExprEmitter::EmitFinalDestCopy(const Expr *E, RValue Src, bool Ignore) {
135 assert(Src.isAggregate() && "value must be aggregate value!");
136
137 // If the result is ignored, don't copy from the value.
138 if (DestPtr == 0) {
139 if (!Src.isVolatileQualified() || (IgnoreResult && Ignore))
140 return;
141 // If the source is volatile, we must read from it; to do that, we need
142 // some place to put it.
143 DestPtr = CGF.CreateTempAlloca(CGF.ConvertType(E->getType()), "agg.tmp");
144 }
145
146 // If the result of the assignment is used, copy the LHS there also.
147 // FIXME: Pass VolatileDest as well. I think we also need to merge volatile
148 // from the source as well, as we can't eliminate it if either operand
149 // is volatile, unless copy has volatile for both source and destination..
150 CGF.EmitAggregateCopy(DestPtr, Src.getAggregateAddr(), E->getType(),
151 VolatileDest|Src.isVolatileQualified());
152}
153
154/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
155void AggExprEmitter::EmitFinalDestCopy(const Expr *E, LValue Src, bool Ignore) {
156 assert(Src.isSimple() && "Can't have aggregate bitfield, vector, etc");
157
158 EmitFinalDestCopy(E, RValue::getAggregate(Src.getAddress(),
159 Src.isVolatileQualified()),
160 Ignore);
161}
162
163//===----------------------------------------------------------------------===//
164// Visitor Methods
165//===----------------------------------------------------------------------===//
166
167void AggExprEmitter::VisitCStyleCastExpr(CStyleCastExpr *E) {
168 // GCC union extension
|
175 return;
176 }
177
178 Visit(E->getSubExpr());
179}
180
181void AggExprEmitter::VisitImplicitCastExpr(ImplicitCastExpr *E) {
182 assert(CGF.getContext().hasSameUnqualifiedType(E->getSubExpr()->getType(),
183 E->getType()) &&
184 "Implicit cast types must be compatible");
185 Visit(E->getSubExpr());
186}
187
188void AggExprEmitter::VisitCallExpr(const CallExpr *E) {
189 if (E->getCallReturnType()->isReferenceType()) {
190 EmitAggLoadOfLValue(E);
191 return;
192 }
193
194 RValue RV = CGF.EmitCallExpr(E);
195 EmitFinalDestCopy(E, RV);
196}
197
198void AggExprEmitter::VisitObjCMessageExpr(ObjCMessageExpr *E) {
199 RValue RV = CGF.EmitObjCMessageExpr(E);
200 EmitFinalDestCopy(E, RV);
201}
202
203void AggExprEmitter::VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) {
204 RValue RV = CGF.EmitObjCPropertyGet(E);
205 EmitFinalDestCopy(E, RV);
206}
207
208void AggExprEmitter::VisitObjCKVCRefExpr(ObjCKVCRefExpr *E) {
209 RValue RV = CGF.EmitObjCPropertyGet(E);
210 EmitFinalDestCopy(E, RV);
211}
212
213void AggExprEmitter::VisitBinComma(const BinaryOperator *E) {
214 CGF.EmitAnyExpr(E->getLHS(), 0, false, true);
215 CGF.EmitAggExpr(E->getRHS(), DestPtr, VolatileDest);
216}
217
218void AggExprEmitter::VisitStmtExpr(const StmtExpr *E) {
219 CGF.EmitCompoundStmt(*E->getSubStmt(), true, DestPtr, VolatileDest);
220}
221
222void AggExprEmitter::VisitBinaryOperator(const BinaryOperator *E) {
223 CGF.ErrorUnsupported(E, "aggregate binary expression");
224}
225
226void AggExprEmitter::VisitBinAssign(const BinaryOperator *E) {
227 // For an assignment to work, the value on the right has
228 // to be compatible with the value on the left.
229 assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
230 E->getRHS()->getType())
231 && "Invalid assignment");
232 LValue LHS = CGF.EmitLValue(E->getLHS());
233
234 // We have to special case property setters, otherwise we must have
235 // a simple lvalue (no aggregates inside vectors, bitfields).
236 if (LHS.isPropertyRef()) {
237 llvm::Value *AggLoc = DestPtr;
238 if (!AggLoc)
239 AggLoc = CGF.CreateTempAlloca(CGF.ConvertType(E->getRHS()->getType()));
240 CGF.EmitAggExpr(E->getRHS(), AggLoc, VolatileDest);
241 CGF.EmitObjCPropertySet(LHS.getPropertyRefExpr(),
242 RValue::getAggregate(AggLoc, VolatileDest));
243 }
244 else if (LHS.isKVCRef()) {
245 llvm::Value *AggLoc = DestPtr;
246 if (!AggLoc)
247 AggLoc = CGF.CreateTempAlloca(CGF.ConvertType(E->getRHS()->getType()));
248 CGF.EmitAggExpr(E->getRHS(), AggLoc, VolatileDest);
249 CGF.EmitObjCPropertySet(LHS.getKVCRefExpr(),
250 RValue::getAggregate(AggLoc, VolatileDest));
251 } else {
252 // Codegen the RHS so that it stores directly into the LHS.
253 CGF.EmitAggExpr(E->getRHS(), LHS.getAddress(), LHS.isVolatileQualified());
254 EmitFinalDestCopy(E, LHS, true);
255 }
256}
257
258void AggExprEmitter::VisitConditionalOperator(const ConditionalOperator *E) {
259 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
260 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
261 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
262
263 llvm::Value *Cond = CGF.EvaluateExprAsBool(E->getCond());
264 Builder.CreateCondBr(Cond, LHSBlock, RHSBlock);
265
266 CGF.EmitBlock(LHSBlock);
267
268 // Handle the GNU extension for missing LHS.
269 assert(E->getLHS() && "Must have LHS for aggregate value");
270
271 Visit(E->getLHS());
272 CGF.EmitBranch(ContBlock);
273
274 CGF.EmitBlock(RHSBlock);
275
276 Visit(E->getRHS());
277 CGF.EmitBranch(ContBlock);
278
279 CGF.EmitBlock(ContBlock);
280}
281
282void AggExprEmitter::VisitVAArgExpr(VAArgExpr *VE) {
283 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr());
284 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType());
285
286 if (!ArgPtr) {
287 CGF.ErrorUnsupported(VE, "aggregate va_arg expression");
288 return;
289 }
290
291 EmitFinalDestCopy(VE, LValue::MakeAddr(ArgPtr, 0));
292}
293
294void AggExprEmitter::VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
295 llvm::Value *Val = DestPtr;
296
297 if (!Val) {
298 // Create a temporary variable.
299 Val = CGF.CreateTempAlloca(CGF.ConvertTypeForMem(E->getType()), "tmp");
300
301 // FIXME: volatile
302 CGF.EmitAggExpr(E->getSubExpr(), Val, false);
303 } else
304 Visit(E->getSubExpr());
305
306 CGF.PushCXXTemporary(E->getTemporary(), Val);
307}
308
309void
310AggExprEmitter::VisitCXXConstructExpr(const CXXConstructExpr *E) {
311 llvm::Value *Val = DestPtr;
312
313 if (!Val) {
314 // Create a temporary variable.
315 Val = CGF.CreateTempAlloca(CGF.ConvertTypeForMem(E->getType()), "tmp");
316 }
317
318 CGF.EmitCXXConstructExpr(Val, E);
319}
320
321void AggExprEmitter::VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) {
322 CGF.EmitCXXExprWithTemporaries(E, DestPtr, VolatileDest);
323}
324
325void AggExprEmitter::EmitInitializationToLValue(Expr* E, LValue LV) {
326 // FIXME: Ignore result?
327 // FIXME: Are initializers affected by volatile?
328 if (isa<ImplicitValueInitExpr>(E)) {
329 EmitNullInitializationToLValue(LV, E->getType());
330 } else if (E->getType()->isComplexType()) {
331 CGF.EmitComplexExprIntoAddr(E, LV.getAddress(), false);
332 } else if (CGF.hasAggregateLLVMType(E->getType())) {
333 CGF.EmitAnyExpr(E, LV.getAddress(), false);
334 } else {
335 CGF.EmitStoreThroughLValue(CGF.EmitAnyExpr(E), LV, E->getType());
336 }
337}
338
339void AggExprEmitter::EmitNullInitializationToLValue(LValue LV, QualType T) {
340 if (!CGF.hasAggregateLLVMType(T)) {
341 // For non-aggregates, we can store zero
342 llvm::Value *Null = llvm::Constant::getNullValue(CGF.ConvertType(T));
343 CGF.EmitStoreThroughLValue(RValue::get(Null), LV, T);
344 } else {
345 // Otherwise, just memset the whole thing to zero. This is legal
346 // because in LLVM, all default initializers are guaranteed to have a
347 // bit pattern of all zeros.
348 // FIXME: That isn't true for member pointers!
349 // There's a potential optimization opportunity in combining
350 // memsets; that would be easy for arrays, but relatively
351 // difficult for structures with the current code.
352 CGF.EmitMemSetToZero(LV.getAddress(), T);
353 }
354}
355
356void AggExprEmitter::VisitInitListExpr(InitListExpr *E) {
357#if 0
358 // FIXME: Disabled while we figure out what to do about
359 // test/CodeGen/bitfield.c
360 //
361 // If we can, prefer a copy from a global; this is a lot less code for long
362 // globals, and it's easier for the current optimizers to analyze.
363 // FIXME: Should we really be doing this? Should we try to avoid cases where
364 // we emit a global with a lot of zeros? Should we try to avoid short
365 // globals?
366 if (E->isConstantInitializer(CGF.getContext(), 0)) {
367 llvm::Constant* C = CGF.CGM.EmitConstantExpr(E, &CGF);
368 llvm::GlobalVariable* GV =
369 new llvm::GlobalVariable(C->getType(), true,
370 llvm::GlobalValue::InternalLinkage,
371 C, "", &CGF.CGM.getModule(), 0);
372 EmitFinalDestCopy(E, LValue::MakeAddr(GV, 0));
373 return;
374 }
375#endif
376 if (E->hadArrayRangeDesignator()) {
377 CGF.ErrorUnsupported(E, "GNU array range designator extension");
378 }
379
380 // Handle initialization of an array.
381 if (E->getType()->isArrayType()) {
382 const llvm::PointerType *APType =
383 cast<llvm::PointerType>(DestPtr->getType());
384 const llvm::ArrayType *AType =
385 cast<llvm::ArrayType>(APType->getElementType());
386
387 uint64_t NumInitElements = E->getNumInits();
388
389 if (E->getNumInits() > 0) {
390 QualType T1 = E->getType();
391 QualType T2 = E->getInit(0)->getType();
392 if (CGF.getContext().hasSameUnqualifiedType(T1, T2)) {
393 EmitAggLoadOfLValue(E->getInit(0));
394 return;
395 }
396 }
397
398 uint64_t NumArrayElements = AType->getNumElements();
399 QualType ElementType = CGF.getContext().getCanonicalType(E->getType());
400 ElementType = CGF.getContext().getAsArrayType(ElementType)->getElementType();
401
402 unsigned CVRqualifier = ElementType.getCVRQualifiers();
403
404 for (uint64_t i = 0; i != NumArrayElements; ++i) {
405 llvm::Value *NextVal = Builder.CreateStructGEP(DestPtr, i, ".array");
406 if (i < NumInitElements)
407 EmitInitializationToLValue(E->getInit(i),
408 LValue::MakeAddr(NextVal, CVRqualifier));
409 else
410 EmitNullInitializationToLValue(LValue::MakeAddr(NextVal, CVRqualifier),
411 ElementType);
412 }
413 return;
414 }
415
416 assert(E->getType()->isRecordType() && "Only support structs/unions here!");
417
418 // Do struct initialization; this code just sets each individual member
419 // to the approprate value. This makes bitfield support automatic;
420 // the disadvantage is that the generated code is more difficult for
421 // the optimizer, especially with bitfields.
422 unsigned NumInitElements = E->getNumInits();
423 RecordDecl *SD = E->getType()->getAsRecordType()->getDecl();
424 unsigned CurInitVal = 0;
425
426 if (E->getType()->isUnionType()) {
427 // Only initialize one field of a union. The field itself is
428 // specified by the initializer list.
429 if (!E->getInitializedFieldInUnion()) {
430 // Empty union; we have nothing to do.
431
432#ifndef NDEBUG
433 // Make sure that it's really an empty and not a failure of
434 // semantic analysis.
435 for (RecordDecl::field_iterator Field = SD->field_begin(CGF.getContext()),
436 FieldEnd = SD->field_end(CGF.getContext());
437 Field != FieldEnd; ++Field)
438 assert(Field->isUnnamedBitfield() && "Only unnamed bitfields allowed");
439#endif
440 return;
441 }
442
443 // FIXME: volatility
444 FieldDecl *Field = E->getInitializedFieldInUnion();
445 LValue FieldLoc = CGF.EmitLValueForField(DestPtr, Field, true, 0);
446
447 if (NumInitElements) {
448 // Store the initializer into the field
449 EmitInitializationToLValue(E->getInit(0), FieldLoc);
450 } else {
451 // Default-initialize to null
452 EmitNullInitializationToLValue(FieldLoc, Field->getType());
453 }
454
455 return;
456 }
457
458 // Here we iterate over the fields; this makes it simpler to both
459 // default-initialize fields and skip over unnamed fields.
460 for (RecordDecl::field_iterator Field = SD->field_begin(CGF.getContext()),
461 FieldEnd = SD->field_end(CGF.getContext());
462 Field != FieldEnd; ++Field) {
463 // We're done once we hit the flexible array member
464 if (Field->getType()->isIncompleteArrayType())
465 break;
466
467 if (Field->isUnnamedBitfield())
468 continue;
469
470 // FIXME: volatility
471 LValue FieldLoc = CGF.EmitLValueForField(DestPtr, *Field, false, 0);
472 // We never generate write-barries for initialized fields.
473 LValue::SetObjCNonGC(FieldLoc, true);
474 if (CurInitVal < NumInitElements) {
475 // Store the initializer into the field
476 EmitInitializationToLValue(E->getInit(CurInitVal++), FieldLoc);
477 } else {
478 // We're out of initalizers; default-initialize to null
479 EmitNullInitializationToLValue(FieldLoc, Field->getType());
480 }
481 }
482}
483
484//===----------------------------------------------------------------------===//
485// Entry Points into this File
486//===----------------------------------------------------------------------===//
487
488/// EmitAggExpr - Emit the computation of the specified expression of aggregate
489/// type. The result is computed into DestPtr. Note that if DestPtr is null,
490/// the value of the aggregate expression is not needed. If VolatileDest is
491/// true, DestPtr cannot be 0.
492void CodeGenFunction::EmitAggExpr(const Expr *E, llvm::Value *DestPtr,
493 bool VolatileDest, bool IgnoreResult) {
494 assert(E && hasAggregateLLVMType(E->getType()) &&
495 "Invalid aggregate expression to emit");
496 assert ((DestPtr != 0 || VolatileDest == false)
497 && "volatile aggregate can't be 0");
498
499 AggExprEmitter(*this, DestPtr, VolatileDest, IgnoreResult)
500 .Visit(const_cast<Expr*>(E));
501}
502
503void CodeGenFunction::EmitAggregateClear(llvm::Value *DestPtr, QualType Ty) {
504 assert(!Ty->isAnyComplexType() && "Shouldn't happen for complex");
505
506 EmitMemSetToZero(DestPtr, Ty);
507}
508
509void CodeGenFunction::EmitAggregateCopy(llvm::Value *DestPtr,
510 llvm::Value *SrcPtr, QualType Ty,
511 bool isVolatile) {
512 assert(!Ty->isAnyComplexType() && "Shouldn't happen for complex");
513
514 // Aggregate assignment turns into llvm.memcpy. This is almost valid per
515 // C99 6.5.16.1p3, which states "If the value being stored in an object is
516 // read from another object that overlaps in anyway the storage of the first
517 // object, then the overlap shall be exact and the two objects shall have
518 // qualified or unqualified versions of a compatible type."
519 //
520 // memcpy is not defined if the source and destination pointers are exactly
521 // equal, but other compilers do this optimization, and almost every memcpy
522 // implementation handles this case safely. If there is a libc that does not
523 // safely handle this, we can add a target hook.
524 const llvm::Type *BP = llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
525 if (DestPtr->getType() != BP)
526 DestPtr = Builder.CreateBitCast(DestPtr, BP, "tmp");
527 if (SrcPtr->getType() != BP)
528 SrcPtr = Builder.CreateBitCast(SrcPtr, BP, "tmp");
529
530 // Get size and alignment info for this aggregate.
531 std::pair<uint64_t, unsigned> TypeInfo = getContext().getTypeInfo(Ty);
532
533 // FIXME: Handle variable sized types.
534 const llvm::Type *IntPtr = llvm::IntegerType::get(LLVMPointerWidth);
535
536 // FIXME: If we have a volatile struct, the optimizer can remove what might
537 // appear to be `extra' memory ops:
538 //
539 // volatile struct { int i; } a, b;
540 //
541 // int main() {
542 // a = b;
543 // a = b;
544 // }
545 //
546 // we need to use a differnt call here. We use isVolatile to indicate when
547 // either the source or the destination is volatile.
548 Builder.CreateCall4(CGM.getMemCpyFn(),
549 DestPtr, SrcPtr,
550 // TypeInfo.first describes size in bits.
551 llvm::ConstantInt::get(IntPtr, TypeInfo.first/8),
552 llvm::ConstantInt::get(llvm::Type::Int32Ty,
553 TypeInfo.second/8));
554}
| 175 return;
176 }
177
178 Visit(E->getSubExpr());
179}
180
181void AggExprEmitter::VisitImplicitCastExpr(ImplicitCastExpr *E) {
182 assert(CGF.getContext().hasSameUnqualifiedType(E->getSubExpr()->getType(),
183 E->getType()) &&
184 "Implicit cast types must be compatible");
185 Visit(E->getSubExpr());
186}
187
188void AggExprEmitter::VisitCallExpr(const CallExpr *E) {
189 if (E->getCallReturnType()->isReferenceType()) {
190 EmitAggLoadOfLValue(E);
191 return;
192 }
193
194 RValue RV = CGF.EmitCallExpr(E);
195 EmitFinalDestCopy(E, RV);
196}
197
198void AggExprEmitter::VisitObjCMessageExpr(ObjCMessageExpr *E) {
199 RValue RV = CGF.EmitObjCMessageExpr(E);
200 EmitFinalDestCopy(E, RV);
201}
202
203void AggExprEmitter::VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) {
204 RValue RV = CGF.EmitObjCPropertyGet(E);
205 EmitFinalDestCopy(E, RV);
206}
207
208void AggExprEmitter::VisitObjCKVCRefExpr(ObjCKVCRefExpr *E) {
209 RValue RV = CGF.EmitObjCPropertyGet(E);
210 EmitFinalDestCopy(E, RV);
211}
212
213void AggExprEmitter::VisitBinComma(const BinaryOperator *E) {
214 CGF.EmitAnyExpr(E->getLHS(), 0, false, true);
215 CGF.EmitAggExpr(E->getRHS(), DestPtr, VolatileDest);
216}
217
218void AggExprEmitter::VisitStmtExpr(const StmtExpr *E) {
219 CGF.EmitCompoundStmt(*E->getSubStmt(), true, DestPtr, VolatileDest);
220}
221
222void AggExprEmitter::VisitBinaryOperator(const BinaryOperator *E) {
223 CGF.ErrorUnsupported(E, "aggregate binary expression");
224}
225
226void AggExprEmitter::VisitBinAssign(const BinaryOperator *E) {
227 // For an assignment to work, the value on the right has
228 // to be compatible with the value on the left.
229 assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
230 E->getRHS()->getType())
231 && "Invalid assignment");
232 LValue LHS = CGF.EmitLValue(E->getLHS());
233
234 // We have to special case property setters, otherwise we must have
235 // a simple lvalue (no aggregates inside vectors, bitfields).
236 if (LHS.isPropertyRef()) {
237 llvm::Value *AggLoc = DestPtr;
238 if (!AggLoc)
239 AggLoc = CGF.CreateTempAlloca(CGF.ConvertType(E->getRHS()->getType()));
240 CGF.EmitAggExpr(E->getRHS(), AggLoc, VolatileDest);
241 CGF.EmitObjCPropertySet(LHS.getPropertyRefExpr(),
242 RValue::getAggregate(AggLoc, VolatileDest));
243 }
244 else if (LHS.isKVCRef()) {
245 llvm::Value *AggLoc = DestPtr;
246 if (!AggLoc)
247 AggLoc = CGF.CreateTempAlloca(CGF.ConvertType(E->getRHS()->getType()));
248 CGF.EmitAggExpr(E->getRHS(), AggLoc, VolatileDest);
249 CGF.EmitObjCPropertySet(LHS.getKVCRefExpr(),
250 RValue::getAggregate(AggLoc, VolatileDest));
251 } else {
252 // Codegen the RHS so that it stores directly into the LHS.
253 CGF.EmitAggExpr(E->getRHS(), LHS.getAddress(), LHS.isVolatileQualified());
254 EmitFinalDestCopy(E, LHS, true);
255 }
256}
257
258void AggExprEmitter::VisitConditionalOperator(const ConditionalOperator *E) {
259 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
260 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
261 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
262
263 llvm::Value *Cond = CGF.EvaluateExprAsBool(E->getCond());
264 Builder.CreateCondBr(Cond, LHSBlock, RHSBlock);
265
266 CGF.EmitBlock(LHSBlock);
267
268 // Handle the GNU extension for missing LHS.
269 assert(E->getLHS() && "Must have LHS for aggregate value");
270
271 Visit(E->getLHS());
272 CGF.EmitBranch(ContBlock);
273
274 CGF.EmitBlock(RHSBlock);
275
276 Visit(E->getRHS());
277 CGF.EmitBranch(ContBlock);
278
279 CGF.EmitBlock(ContBlock);
280}
281
282void AggExprEmitter::VisitVAArgExpr(VAArgExpr *VE) {
283 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr());
284 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType());
285
286 if (!ArgPtr) {
287 CGF.ErrorUnsupported(VE, "aggregate va_arg expression");
288 return;
289 }
290
291 EmitFinalDestCopy(VE, LValue::MakeAddr(ArgPtr, 0));
292}
293
294void AggExprEmitter::VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
295 llvm::Value *Val = DestPtr;
296
297 if (!Val) {
298 // Create a temporary variable.
299 Val = CGF.CreateTempAlloca(CGF.ConvertTypeForMem(E->getType()), "tmp");
300
301 // FIXME: volatile
302 CGF.EmitAggExpr(E->getSubExpr(), Val, false);
303 } else
304 Visit(E->getSubExpr());
305
306 CGF.PushCXXTemporary(E->getTemporary(), Val);
307}
308
309void
310AggExprEmitter::VisitCXXConstructExpr(const CXXConstructExpr *E) {
311 llvm::Value *Val = DestPtr;
312
313 if (!Val) {
314 // Create a temporary variable.
315 Val = CGF.CreateTempAlloca(CGF.ConvertTypeForMem(E->getType()), "tmp");
316 }
317
318 CGF.EmitCXXConstructExpr(Val, E);
319}
320
321void AggExprEmitter::VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) {
322 CGF.EmitCXXExprWithTemporaries(E, DestPtr, VolatileDest);
323}
324
325void AggExprEmitter::EmitInitializationToLValue(Expr* E, LValue LV) {
326 // FIXME: Ignore result?
327 // FIXME: Are initializers affected by volatile?
328 if (isa<ImplicitValueInitExpr>(E)) {
329 EmitNullInitializationToLValue(LV, E->getType());
330 } else if (E->getType()->isComplexType()) {
331 CGF.EmitComplexExprIntoAddr(E, LV.getAddress(), false);
332 } else if (CGF.hasAggregateLLVMType(E->getType())) {
333 CGF.EmitAnyExpr(E, LV.getAddress(), false);
334 } else {
335 CGF.EmitStoreThroughLValue(CGF.EmitAnyExpr(E), LV, E->getType());
336 }
337}
338
339void AggExprEmitter::EmitNullInitializationToLValue(LValue LV, QualType T) {
340 if (!CGF.hasAggregateLLVMType(T)) {
341 // For non-aggregates, we can store zero
342 llvm::Value *Null = llvm::Constant::getNullValue(CGF.ConvertType(T));
343 CGF.EmitStoreThroughLValue(RValue::get(Null), LV, T);
344 } else {
345 // Otherwise, just memset the whole thing to zero. This is legal
346 // because in LLVM, all default initializers are guaranteed to have a
347 // bit pattern of all zeros.
348 // FIXME: That isn't true for member pointers!
349 // There's a potential optimization opportunity in combining
350 // memsets; that would be easy for arrays, but relatively
351 // difficult for structures with the current code.
352 CGF.EmitMemSetToZero(LV.getAddress(), T);
353 }
354}
355
356void AggExprEmitter::VisitInitListExpr(InitListExpr *E) {
357#if 0
358 // FIXME: Disabled while we figure out what to do about
359 // test/CodeGen/bitfield.c
360 //
361 // If we can, prefer a copy from a global; this is a lot less code for long
362 // globals, and it's easier for the current optimizers to analyze.
363 // FIXME: Should we really be doing this? Should we try to avoid cases where
364 // we emit a global with a lot of zeros? Should we try to avoid short
365 // globals?
366 if (E->isConstantInitializer(CGF.getContext(), 0)) {
367 llvm::Constant* C = CGF.CGM.EmitConstantExpr(E, &CGF);
368 llvm::GlobalVariable* GV =
369 new llvm::GlobalVariable(C->getType(), true,
370 llvm::GlobalValue::InternalLinkage,
371 C, "", &CGF.CGM.getModule(), 0);
372 EmitFinalDestCopy(E, LValue::MakeAddr(GV, 0));
373 return;
374 }
375#endif
376 if (E->hadArrayRangeDesignator()) {
377 CGF.ErrorUnsupported(E, "GNU array range designator extension");
378 }
379
380 // Handle initialization of an array.
381 if (E->getType()->isArrayType()) {
382 const llvm::PointerType *APType =
383 cast<llvm::PointerType>(DestPtr->getType());
384 const llvm::ArrayType *AType =
385 cast<llvm::ArrayType>(APType->getElementType());
386
387 uint64_t NumInitElements = E->getNumInits();
388
389 if (E->getNumInits() > 0) {
390 QualType T1 = E->getType();
391 QualType T2 = E->getInit(0)->getType();
392 if (CGF.getContext().hasSameUnqualifiedType(T1, T2)) {
393 EmitAggLoadOfLValue(E->getInit(0));
394 return;
395 }
396 }
397
398 uint64_t NumArrayElements = AType->getNumElements();
399 QualType ElementType = CGF.getContext().getCanonicalType(E->getType());
400 ElementType = CGF.getContext().getAsArrayType(ElementType)->getElementType();
401
402 unsigned CVRqualifier = ElementType.getCVRQualifiers();
403
404 for (uint64_t i = 0; i != NumArrayElements; ++i) {
405 llvm::Value *NextVal = Builder.CreateStructGEP(DestPtr, i, ".array");
406 if (i < NumInitElements)
407 EmitInitializationToLValue(E->getInit(i),
408 LValue::MakeAddr(NextVal, CVRqualifier));
409 else
410 EmitNullInitializationToLValue(LValue::MakeAddr(NextVal, CVRqualifier),
411 ElementType);
412 }
413 return;
414 }
415
416 assert(E->getType()->isRecordType() && "Only support structs/unions here!");
417
418 // Do struct initialization; this code just sets each individual member
419 // to the approprate value. This makes bitfield support automatic;
420 // the disadvantage is that the generated code is more difficult for
421 // the optimizer, especially with bitfields.
422 unsigned NumInitElements = E->getNumInits();
423 RecordDecl *SD = E->getType()->getAsRecordType()->getDecl();
424 unsigned CurInitVal = 0;
425
426 if (E->getType()->isUnionType()) {
427 // Only initialize one field of a union. The field itself is
428 // specified by the initializer list.
429 if (!E->getInitializedFieldInUnion()) {
430 // Empty union; we have nothing to do.
431
432#ifndef NDEBUG
433 // Make sure that it's really an empty and not a failure of
434 // semantic analysis.
435 for (RecordDecl::field_iterator Field = SD->field_begin(CGF.getContext()),
436 FieldEnd = SD->field_end(CGF.getContext());
437 Field != FieldEnd; ++Field)
438 assert(Field->isUnnamedBitfield() && "Only unnamed bitfields allowed");
439#endif
440 return;
441 }
442
443 // FIXME: volatility
444 FieldDecl *Field = E->getInitializedFieldInUnion();
445 LValue FieldLoc = CGF.EmitLValueForField(DestPtr, Field, true, 0);
446
447 if (NumInitElements) {
448 // Store the initializer into the field
449 EmitInitializationToLValue(E->getInit(0), FieldLoc);
450 } else {
451 // Default-initialize to null
452 EmitNullInitializationToLValue(FieldLoc, Field->getType());
453 }
454
455 return;
456 }
457
458 // Here we iterate over the fields; this makes it simpler to both
459 // default-initialize fields and skip over unnamed fields.
460 for (RecordDecl::field_iterator Field = SD->field_begin(CGF.getContext()),
461 FieldEnd = SD->field_end(CGF.getContext());
462 Field != FieldEnd; ++Field) {
463 // We're done once we hit the flexible array member
464 if (Field->getType()->isIncompleteArrayType())
465 break;
466
467 if (Field->isUnnamedBitfield())
468 continue;
469
470 // FIXME: volatility
471 LValue FieldLoc = CGF.EmitLValueForField(DestPtr, *Field, false, 0);
472 // We never generate write-barries for initialized fields.
473 LValue::SetObjCNonGC(FieldLoc, true);
474 if (CurInitVal < NumInitElements) {
475 // Store the initializer into the field
476 EmitInitializationToLValue(E->getInit(CurInitVal++), FieldLoc);
477 } else {
478 // We're out of initalizers; default-initialize to null
479 EmitNullInitializationToLValue(FieldLoc, Field->getType());
480 }
481 }
482}
483
484//===----------------------------------------------------------------------===//
485// Entry Points into this File
486//===----------------------------------------------------------------------===//
487
488/// EmitAggExpr - Emit the computation of the specified expression of aggregate
489/// type. The result is computed into DestPtr. Note that if DestPtr is null,
490/// the value of the aggregate expression is not needed. If VolatileDest is
491/// true, DestPtr cannot be 0.
492void CodeGenFunction::EmitAggExpr(const Expr *E, llvm::Value *DestPtr,
493 bool VolatileDest, bool IgnoreResult) {
494 assert(E && hasAggregateLLVMType(E->getType()) &&
495 "Invalid aggregate expression to emit");
496 assert ((DestPtr != 0 || VolatileDest == false)
497 && "volatile aggregate can't be 0");
498
499 AggExprEmitter(*this, DestPtr, VolatileDest, IgnoreResult)
500 .Visit(const_cast<Expr*>(E));
501}
502
503void CodeGenFunction::EmitAggregateClear(llvm::Value *DestPtr, QualType Ty) {
504 assert(!Ty->isAnyComplexType() && "Shouldn't happen for complex");
505
506 EmitMemSetToZero(DestPtr, Ty);
507}
508
509void CodeGenFunction::EmitAggregateCopy(llvm::Value *DestPtr,
510 llvm::Value *SrcPtr, QualType Ty,
511 bool isVolatile) {
512 assert(!Ty->isAnyComplexType() && "Shouldn't happen for complex");
513
514 // Aggregate assignment turns into llvm.memcpy. This is almost valid per
515 // C99 6.5.16.1p3, which states "If the value being stored in an object is
516 // read from another object that overlaps in anyway the storage of the first
517 // object, then the overlap shall be exact and the two objects shall have
518 // qualified or unqualified versions of a compatible type."
519 //
520 // memcpy is not defined if the source and destination pointers are exactly
521 // equal, but other compilers do this optimization, and almost every memcpy
522 // implementation handles this case safely. If there is a libc that does not
523 // safely handle this, we can add a target hook.
524 const llvm::Type *BP = llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
525 if (DestPtr->getType() != BP)
526 DestPtr = Builder.CreateBitCast(DestPtr, BP, "tmp");
527 if (SrcPtr->getType() != BP)
528 SrcPtr = Builder.CreateBitCast(SrcPtr, BP, "tmp");
529
530 // Get size and alignment info for this aggregate.
531 std::pair<uint64_t, unsigned> TypeInfo = getContext().getTypeInfo(Ty);
532
533 // FIXME: Handle variable sized types.
534 const llvm::Type *IntPtr = llvm::IntegerType::get(LLVMPointerWidth);
535
536 // FIXME: If we have a volatile struct, the optimizer can remove what might
537 // appear to be `extra' memory ops:
538 //
539 // volatile struct { int i; } a, b;
540 //
541 // int main() {
542 // a = b;
543 // a = b;
544 // }
545 //
546 // we need to use a differnt call here. We use isVolatile to indicate when
547 // either the source or the destination is volatile.
548 Builder.CreateCall4(CGM.getMemCpyFn(),
549 DestPtr, SrcPtr,
550 // TypeInfo.first describes size in bits.
551 llvm::ConstantInt::get(IntPtr, TypeInfo.first/8),
552 llvm::ConstantInt::get(llvm::Type::Int32Ty,
553 TypeInfo.second/8));
554}
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