1 //===--- CodeGenFunction.cpp - Emit LLVM Code from ASTs for a Function ----===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This coordinates the per-function state used while generating code.
12 //===----------------------------------------------------------------------===//
14 #include "CodeGenFunction.h"
15 #include "CGCUDARuntime.h"
17 #include "CGDebugInfo.h"
18 #include "CodeGenModule.h"
19 #include "TargetInfo.h"
20 #include "clang/AST/ASTContext.h"
21 #include "clang/AST/Decl.h"
22 #include "clang/AST/DeclCXX.h"
23 #include "clang/AST/StmtCXX.h"
24 #include "clang/Basic/OpenCL.h"
25 #include "clang/Basic/TargetInfo.h"
26 #include "clang/CodeGen/CGFunctionInfo.h"
27 #include "clang/Frontend/CodeGenOptions.h"
28 #include "llvm/IR/DataLayout.h"
29 #include "llvm/IR/Intrinsics.h"
30 #include "llvm/IR/MDBuilder.h"
31 #include "llvm/IR/Operator.h"
32 using namespace clang;
33 using namespace CodeGen;
35 CodeGenFunction::CodeGenFunction(CodeGenModule &cgm, bool suppressNewContext)
36 : CodeGenTypeCache(cgm), CGM(cgm), Target(cgm.getTarget()),
37 Builder(cgm.getModule().getContext()), CapturedStmtInfo(0),
38 SanitizePerformTypeCheck(CGM.getSanOpts().Null |
39 CGM.getSanOpts().Alignment |
40 CGM.getSanOpts().ObjectSize |
41 CGM.getSanOpts().Vptr),
42 SanOpts(&CGM.getSanOpts()), AutoreleaseResult(false), BlockInfo(0),
43 BlockPointer(0), LambdaThisCaptureField(0), NormalCleanupDest(0),
44 NextCleanupDestIndex(1), FirstBlockInfo(0), EHResumeBlock(0),
45 ExceptionSlot(0), EHSelectorSlot(0), DebugInfo(CGM.getModuleDebugInfo()),
46 DisableDebugInfo(false), DidCallStackSave(false), IndirectBranch(0),
47 SwitchInsn(0), CaseRangeBlock(0), UnreachableBlock(0), NumReturnExprs(0),
48 NumSimpleReturnExprs(0), CXXABIThisDecl(0), CXXABIThisValue(0),
49 CXXThisValue(0), CXXDefaultInitExprThis(0),
50 CXXStructorImplicitParamDecl(0), CXXStructorImplicitParamValue(0),
51 OutermostConditional(0), CurLexicalScope(0), TerminateLandingPad(0),
52 TerminateHandler(0), TrapBB(0) {
53 if (!suppressNewContext)
54 CGM.getCXXABI().getMangleContext().startNewFunction();
56 llvm::FastMathFlags FMF;
57 if (CGM.getLangOpts().FastMath)
58 FMF.setUnsafeAlgebra();
59 if (CGM.getLangOpts().FiniteMathOnly) {
63 Builder.SetFastMathFlags(FMF);
66 CodeGenFunction::~CodeGenFunction() {
67 assert(LifetimeExtendedCleanupStack.empty() && "failed to emit a cleanup");
69 // If there are any unclaimed block infos, go ahead and destroy them
70 // now. This can happen if IR-gen gets clever and skips evaluating
73 destroyBlockInfos(FirstBlockInfo);
77 llvm::Type *CodeGenFunction::ConvertTypeForMem(QualType T) {
78 return CGM.getTypes().ConvertTypeForMem(T);
81 llvm::Type *CodeGenFunction::ConvertType(QualType T) {
82 return CGM.getTypes().ConvertType(T);
85 TypeEvaluationKind CodeGenFunction::getEvaluationKind(QualType type) {
86 type = type.getCanonicalType();
88 switch (type->getTypeClass()) {
89 #define TYPE(name, parent)
90 #define ABSTRACT_TYPE(name, parent)
91 #define NON_CANONICAL_TYPE(name, parent) case Type::name:
92 #define DEPENDENT_TYPE(name, parent) case Type::name:
93 #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(name, parent) case Type::name:
94 #include "clang/AST/TypeNodes.def"
95 llvm_unreachable("non-canonical or dependent type in IR-generation");
98 llvm_unreachable("undeduced auto type in IR-generation");
100 // Various scalar types.
103 case Type::BlockPointer:
104 case Type::LValueReference:
105 case Type::RValueReference:
106 case Type::MemberPointer:
108 case Type::ExtVector:
109 case Type::FunctionProto:
110 case Type::FunctionNoProto:
112 case Type::ObjCObjectPointer:
119 // Arrays, records, and Objective-C objects.
120 case Type::ConstantArray:
121 case Type::IncompleteArray:
122 case Type::VariableArray:
124 case Type::ObjCObject:
125 case Type::ObjCInterface:
126 return TEK_Aggregate;
128 // We operate on atomic values according to their underlying type.
130 type = cast<AtomicType>(type)->getValueType();
133 llvm_unreachable("unknown type kind!");
137 void CodeGenFunction::EmitReturnBlock() {
138 // For cleanliness, we try to avoid emitting the return block for
140 llvm::BasicBlock *CurBB = Builder.GetInsertBlock();
143 assert(!CurBB->getTerminator() && "Unexpected terminated block.");
145 // We have a valid insert point, reuse it if it is empty or there are no
146 // explicit jumps to the return block.
147 if (CurBB->empty() || ReturnBlock.getBlock()->use_empty()) {
148 ReturnBlock.getBlock()->replaceAllUsesWith(CurBB);
149 delete ReturnBlock.getBlock();
151 EmitBlock(ReturnBlock.getBlock());
155 // Otherwise, if the return block is the target of a single direct
156 // branch then we can just put the code in that block instead. This
157 // cleans up functions which started with a unified return block.
158 if (ReturnBlock.getBlock()->hasOneUse()) {
159 llvm::BranchInst *BI =
160 dyn_cast<llvm::BranchInst>(*ReturnBlock.getBlock()->use_begin());
161 if (BI && BI->isUnconditional() &&
162 BI->getSuccessor(0) == ReturnBlock.getBlock()) {
163 // Reset insertion point, including debug location, and delete the
164 // branch. This is really subtle and only works because the next change
165 // in location will hit the caching in CGDebugInfo::EmitLocation and not
167 Builder.SetCurrentDebugLocation(BI->getDebugLoc());
168 Builder.SetInsertPoint(BI->getParent());
169 BI->eraseFromParent();
170 delete ReturnBlock.getBlock();
175 // FIXME: We are at an unreachable point, there is no reason to emit the block
176 // unless it has uses. However, we still need a place to put the debug
177 // region.end for now.
179 EmitBlock(ReturnBlock.getBlock());
182 static void EmitIfUsed(CodeGenFunction &CGF, llvm::BasicBlock *BB) {
184 if (!BB->use_empty())
185 return CGF.CurFn->getBasicBlockList().push_back(BB);
189 void CodeGenFunction::FinishFunction(SourceLocation EndLoc) {
190 assert(BreakContinueStack.empty() &&
191 "mismatched push/pop in break/continue stack!");
193 bool OnlySimpleReturnStmts = NumSimpleReturnExprs > 0
194 && NumSimpleReturnExprs == NumReturnExprs
195 && ReturnBlock.getBlock()->use_empty();
196 // Usually the return expression is evaluated before the cleanup
197 // code. If the function contains only a simple return statement,
198 // such as a constant, the location before the cleanup code becomes
199 // the last useful breakpoint in the function, because the simple
200 // return expression will be evaluated after the cleanup code. To be
201 // safe, set the debug location for cleanup code to the location of
202 // the return statement. Otherwise the cleanup code should be at the
203 // end of the function's lexical scope.
205 // If there are multiple branches to the return block, the branch
206 // instructions will get the location of the return statements and
208 if (CGDebugInfo *DI = getDebugInfo()) {
209 if (OnlySimpleReturnStmts)
210 DI->EmitLocation(Builder, LastStopPoint);
212 DI->EmitLocation(Builder, EndLoc);
215 // Pop any cleanups that might have been associated with the
216 // parameters. Do this in whatever block we're currently in; it's
217 // important to do this before we enter the return block or return
218 // edges will be *really* confused.
219 bool EmitRetDbgLoc = true;
220 if (EHStack.stable_begin() != PrologueCleanupDepth) {
221 PopCleanupBlocks(PrologueCleanupDepth);
223 // Make sure the line table doesn't jump back into the body for
224 // the ret after it's been at EndLoc.
225 EmitRetDbgLoc = false;
227 if (CGDebugInfo *DI = getDebugInfo())
228 if (OnlySimpleReturnStmts)
229 DI->EmitLocation(Builder, EndLoc);
232 // Emit function epilog (to return).
235 if (ShouldInstrumentFunction())
236 EmitFunctionInstrumentation("__cyg_profile_func_exit");
238 // Emit debug descriptor for function end.
239 if (CGDebugInfo *DI = getDebugInfo()) {
240 DI->EmitFunctionEnd(Builder);
243 EmitFunctionEpilog(*CurFnInfo, EmitRetDbgLoc, EndLoc);
244 EmitEndEHSpec(CurCodeDecl);
246 assert(EHStack.empty() &&
247 "did not remove all scopes from cleanup stack!");
249 // If someone did an indirect goto, emit the indirect goto block at the end of
251 if (IndirectBranch) {
252 EmitBlock(IndirectBranch->getParent());
253 Builder.ClearInsertionPoint();
256 // Remove the AllocaInsertPt instruction, which is just a convenience for us.
257 llvm::Instruction *Ptr = AllocaInsertPt;
259 Ptr->eraseFromParent();
261 // If someone took the address of a label but never did an indirect goto, we
262 // made a zero entry PHI node, which is illegal, zap it now.
263 if (IndirectBranch) {
264 llvm::PHINode *PN = cast<llvm::PHINode>(IndirectBranch->getAddress());
265 if (PN->getNumIncomingValues() == 0) {
266 PN->replaceAllUsesWith(llvm::UndefValue::get(PN->getType()));
267 PN->eraseFromParent();
271 EmitIfUsed(*this, EHResumeBlock);
272 EmitIfUsed(*this, TerminateLandingPad);
273 EmitIfUsed(*this, TerminateHandler);
274 EmitIfUsed(*this, UnreachableBlock);
276 if (CGM.getCodeGenOpts().EmitDeclMetadata)
280 /// ShouldInstrumentFunction - Return true if the current function should be
281 /// instrumented with __cyg_profile_func_* calls
282 bool CodeGenFunction::ShouldInstrumentFunction() {
283 if (!CGM.getCodeGenOpts().InstrumentFunctions)
285 if (!CurFuncDecl || CurFuncDecl->hasAttr<NoInstrumentFunctionAttr>())
290 /// EmitFunctionInstrumentation - Emit LLVM code to call the specified
291 /// instrumentation function with the current function and the call site, if
292 /// function instrumentation is enabled.
293 void CodeGenFunction::EmitFunctionInstrumentation(const char *Fn) {
294 // void __cyg_profile_func_{enter,exit} (void *this_fn, void *call_site);
295 llvm::PointerType *PointerTy = Int8PtrTy;
296 llvm::Type *ProfileFuncArgs[] = { PointerTy, PointerTy };
297 llvm::FunctionType *FunctionTy =
298 llvm::FunctionType::get(VoidTy, ProfileFuncArgs, false);
300 llvm::Constant *F = CGM.CreateRuntimeFunction(FunctionTy, Fn);
301 llvm::CallInst *CallSite = Builder.CreateCall(
302 CGM.getIntrinsic(llvm::Intrinsic::returnaddress),
303 llvm::ConstantInt::get(Int32Ty, 0),
306 llvm::Value *args[] = {
307 llvm::ConstantExpr::getBitCast(CurFn, PointerTy),
311 EmitNounwindRuntimeCall(F, args);
314 void CodeGenFunction::EmitMCountInstrumentation() {
315 llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
317 llvm::Constant *MCountFn =
318 CGM.CreateRuntimeFunction(FTy, getTarget().getMCountName());
319 EmitNounwindRuntimeCall(MCountFn);
322 // OpenCL v1.2 s5.6.4.6 allows the compiler to store kernel argument
323 // information in the program executable. The argument information stored
324 // includes the argument name, its type, the address and access qualifiers used.
325 static void GenOpenCLArgMetadata(const FunctionDecl *FD, llvm::Function *Fn,
326 CodeGenModule &CGM,llvm::LLVMContext &Context,
327 SmallVector <llvm::Value*, 5> &kernelMDArgs,
328 CGBuilderTy& Builder, ASTContext &ASTCtx) {
329 // Create MDNodes that represent the kernel arg metadata.
330 // Each MDNode is a list in the form of "key", N number of values which is
331 // the same number of values as their are kernel arguments.
333 // MDNode for the kernel argument address space qualifiers.
334 SmallVector<llvm::Value*, 8> addressQuals;
335 addressQuals.push_back(llvm::MDString::get(Context, "kernel_arg_addr_space"));
337 // MDNode for the kernel argument access qualifiers (images only).
338 SmallVector<llvm::Value*, 8> accessQuals;
339 accessQuals.push_back(llvm::MDString::get(Context, "kernel_arg_access_qual"));
341 // MDNode for the kernel argument type names.
342 SmallVector<llvm::Value*, 8> argTypeNames;
343 argTypeNames.push_back(llvm::MDString::get(Context, "kernel_arg_type"));
345 // MDNode for the kernel argument type qualifiers.
346 SmallVector<llvm::Value*, 8> argTypeQuals;
347 argTypeQuals.push_back(llvm::MDString::get(Context, "kernel_arg_type_qual"));
349 // MDNode for the kernel argument names.
350 SmallVector<llvm::Value*, 8> argNames;
351 argNames.push_back(llvm::MDString::get(Context, "kernel_arg_name"));
353 for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i) {
354 const ParmVarDecl *parm = FD->getParamDecl(i);
355 QualType ty = parm->getType();
356 std::string typeQuals;
358 if (ty->isPointerType()) {
359 QualType pointeeTy = ty->getPointeeType();
361 // Get address qualifier.
362 addressQuals.push_back(Builder.getInt32(ASTCtx.getTargetAddressSpace(
363 pointeeTy.getAddressSpace())));
365 // Get argument type name.
366 std::string typeName = pointeeTy.getUnqualifiedType().getAsString() + "*";
368 // Turn "unsigned type" to "utype"
369 std::string::size_type pos = typeName.find("unsigned");
370 if (pos != std::string::npos)
371 typeName.erase(pos+1, 8);
373 argTypeNames.push_back(llvm::MDString::get(Context, typeName));
375 // Get argument type qualifiers:
376 if (ty.isRestrictQualified())
377 typeQuals = "restrict";
378 if (pointeeTy.isConstQualified() ||
379 (pointeeTy.getAddressSpace() == LangAS::opencl_constant))
380 typeQuals += typeQuals.empty() ? "const" : " const";
381 if (pointeeTy.isVolatileQualified())
382 typeQuals += typeQuals.empty() ? "volatile" : " volatile";
384 addressQuals.push_back(Builder.getInt32(0));
386 // Get argument type name.
387 std::string typeName = ty.getUnqualifiedType().getAsString();
389 // Turn "unsigned type" to "utype"
390 std::string::size_type pos = typeName.find("unsigned");
391 if (pos != std::string::npos)
392 typeName.erase(pos+1, 8);
394 argTypeNames.push_back(llvm::MDString::get(Context, typeName));
396 // Get argument type qualifiers:
397 if (ty.isConstQualified())
399 if (ty.isVolatileQualified())
400 typeQuals += typeQuals.empty() ? "volatile" : " volatile";
403 argTypeQuals.push_back(llvm::MDString::get(Context, typeQuals));
405 // Get image access qualifier:
406 if (ty->isImageType()) {
407 if (parm->hasAttr<OpenCLImageAccessAttr>() &&
408 parm->getAttr<OpenCLImageAccessAttr>()->getAccess() == CLIA_write_only)
409 accessQuals.push_back(llvm::MDString::get(Context, "write_only"));
411 accessQuals.push_back(llvm::MDString::get(Context, "read_only"));
413 accessQuals.push_back(llvm::MDString::get(Context, "none"));
415 // Get argument name.
416 argNames.push_back(llvm::MDString::get(Context, parm->getName()));
419 kernelMDArgs.push_back(llvm::MDNode::get(Context, addressQuals));
420 kernelMDArgs.push_back(llvm::MDNode::get(Context, accessQuals));
421 kernelMDArgs.push_back(llvm::MDNode::get(Context, argTypeNames));
422 kernelMDArgs.push_back(llvm::MDNode::get(Context, argTypeQuals));
423 kernelMDArgs.push_back(llvm::MDNode::get(Context, argNames));
426 void CodeGenFunction::EmitOpenCLKernelMetadata(const FunctionDecl *FD,
429 if (!FD->hasAttr<OpenCLKernelAttr>())
432 llvm::LLVMContext &Context = getLLVMContext();
434 SmallVector <llvm::Value*, 5> kernelMDArgs;
435 kernelMDArgs.push_back(Fn);
437 if (CGM.getCodeGenOpts().EmitOpenCLArgMetadata)
438 GenOpenCLArgMetadata(FD, Fn, CGM, Context, kernelMDArgs,
439 Builder, getContext());
441 if (FD->hasAttr<VecTypeHintAttr>()) {
442 VecTypeHintAttr *attr = FD->getAttr<VecTypeHintAttr>();
443 QualType hintQTy = attr->getTypeHint();
444 const ExtVectorType *hintEltQTy = hintQTy->getAs<ExtVectorType>();
445 bool isSignedInteger =
446 hintQTy->isSignedIntegerType() ||
447 (hintEltQTy && hintEltQTy->getElementType()->isSignedIntegerType());
448 llvm::Value *attrMDArgs[] = {
449 llvm::MDString::get(Context, "vec_type_hint"),
450 llvm::UndefValue::get(CGM.getTypes().ConvertType(attr->getTypeHint())),
451 llvm::ConstantInt::get(
452 llvm::IntegerType::get(Context, 32),
453 llvm::APInt(32, (uint64_t)(isSignedInteger ? 1 : 0)))
455 kernelMDArgs.push_back(llvm::MDNode::get(Context, attrMDArgs));
458 if (FD->hasAttr<WorkGroupSizeHintAttr>()) {
459 WorkGroupSizeHintAttr *attr = FD->getAttr<WorkGroupSizeHintAttr>();
460 llvm::Value *attrMDArgs[] = {
461 llvm::MDString::get(Context, "work_group_size_hint"),
462 Builder.getInt32(attr->getXDim()),
463 Builder.getInt32(attr->getYDim()),
464 Builder.getInt32(attr->getZDim())
466 kernelMDArgs.push_back(llvm::MDNode::get(Context, attrMDArgs));
469 if (FD->hasAttr<ReqdWorkGroupSizeAttr>()) {
470 ReqdWorkGroupSizeAttr *attr = FD->getAttr<ReqdWorkGroupSizeAttr>();
471 llvm::Value *attrMDArgs[] = {
472 llvm::MDString::get(Context, "reqd_work_group_size"),
473 Builder.getInt32(attr->getXDim()),
474 Builder.getInt32(attr->getYDim()),
475 Builder.getInt32(attr->getZDim())
477 kernelMDArgs.push_back(llvm::MDNode::get(Context, attrMDArgs));
480 llvm::MDNode *kernelMDNode = llvm::MDNode::get(Context, kernelMDArgs);
481 llvm::NamedMDNode *OpenCLKernelMetadata =
482 CGM.getModule().getOrInsertNamedMetadata("opencl.kernels");
483 OpenCLKernelMetadata->addOperand(kernelMDNode);
486 void CodeGenFunction::StartFunction(GlobalDecl GD,
489 const CGFunctionInfo &FnInfo,
490 const FunctionArgList &Args,
491 SourceLocation StartLoc) {
492 const Decl *D = GD.getDecl();
494 DidCallStackSave = false;
496 CurFuncDecl = (D ? D->getNonClosureContext() : 0);
500 assert(CurFn->isDeclaration() && "Function already has body?");
502 if (CGM.getSanitizerBlacklist().isIn(*Fn)) {
503 SanOpts = &SanitizerOptions::Disabled;
504 SanitizePerformTypeCheck = false;
507 // Pass inline keyword to optimizer if it appears explicitly on any
509 if (!CGM.getCodeGenOpts().NoInline)
510 if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D))
511 for (FunctionDecl::redecl_iterator RI = FD->redecls_begin(),
512 RE = FD->redecls_end(); RI != RE; ++RI)
513 if (RI->isInlineSpecified()) {
514 Fn->addFnAttr(llvm::Attribute::InlineHint);
518 if (getLangOpts().OpenCL) {
519 // Add metadata for a kernel function.
520 if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D))
521 EmitOpenCLKernelMetadata(FD, Fn);
524 // If we are checking function types, emit a function type signature as
526 if (getLangOpts().CPlusPlus && SanOpts->Function) {
527 if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D)) {
528 if (llvm::Constant *PrefixSig =
529 CGM.getTargetCodeGenInfo().getUBSanFunctionSignature(CGM)) {
530 llvm::Constant *FTRTTIConst =
531 CGM.GetAddrOfRTTIDescriptor(FD->getType(), /*ForEH=*/true);
532 llvm::Constant *PrefixStructElems[] = { PrefixSig, FTRTTIConst };
533 llvm::Constant *PrefixStructConst =
534 llvm::ConstantStruct::getAnon(PrefixStructElems, /*Packed=*/true);
535 Fn->setPrefixData(PrefixStructConst);
540 llvm::BasicBlock *EntryBB = createBasicBlock("entry", CurFn);
542 // Create a marker to make it easy to insert allocas into the entryblock
543 // later. Don't create this with the builder, because we don't want it
545 llvm::Value *Undef = llvm::UndefValue::get(Int32Ty);
546 AllocaInsertPt = new llvm::BitCastInst(Undef, Int32Ty, "", EntryBB);
547 if (Builder.isNamePreserving())
548 AllocaInsertPt->setName("allocapt");
550 ReturnBlock = getJumpDestInCurrentScope("return");
552 Builder.SetInsertPoint(EntryBB);
554 // Emit subprogram debug descriptor.
555 if (CGDebugInfo *DI = getDebugInfo()) {
556 SmallVector<QualType, 16> ArgTypes;
557 for (FunctionArgList::const_iterator i = Args.begin(), e = Args.end();
559 ArgTypes.push_back((*i)->getType());
563 getContext().getFunctionType(RetTy, ArgTypes,
564 FunctionProtoType::ExtProtoInfo());
566 DI->setLocation(StartLoc);
567 DI->EmitFunctionStart(GD, FnType, CurFn, Builder);
570 if (ShouldInstrumentFunction())
571 EmitFunctionInstrumentation("__cyg_profile_func_enter");
573 if (CGM.getCodeGenOpts().InstrumentForProfiling)
574 EmitMCountInstrumentation();
576 if (RetTy->isVoidType()) {
577 // Void type; nothing to return.
579 } else if (CurFnInfo->getReturnInfo().getKind() == ABIArgInfo::Indirect &&
580 !hasScalarEvaluationKind(CurFnInfo->getReturnType())) {
581 // Indirect aggregate return; emit returned value directly into sret slot.
582 // This reduces code size, and affects correctness in C++.
583 ReturnValue = CurFn->arg_begin();
585 ReturnValue = CreateIRTemp(RetTy, "retval");
587 // Tell the epilog emitter to autorelease the result. We do this
588 // now so that various specialized functions can suppress it
589 // during their IR-generation.
590 if (getLangOpts().ObjCAutoRefCount &&
591 !CurFnInfo->isReturnsRetained() &&
592 RetTy->isObjCRetainableType())
593 AutoreleaseResult = true;
596 EmitStartEHSpec(CurCodeDecl);
598 PrologueCleanupDepth = EHStack.stable_begin();
599 EmitFunctionProlog(*CurFnInfo, CurFn, Args);
601 if (D && isa<CXXMethodDecl>(D) && cast<CXXMethodDecl>(D)->isInstance()) {
602 CGM.getCXXABI().EmitInstanceFunctionProlog(*this);
603 const CXXMethodDecl *MD = cast<CXXMethodDecl>(D);
604 if (MD->getParent()->isLambda() &&
605 MD->getOverloadedOperator() == OO_Call) {
606 // We're in a lambda; figure out the captures.
607 MD->getParent()->getCaptureFields(LambdaCaptureFields,
608 LambdaThisCaptureField);
609 if (LambdaThisCaptureField) {
610 // If this lambda captures this, load it.
611 LValue ThisLValue = EmitLValueForLambdaField(LambdaThisCaptureField);
612 CXXThisValue = EmitLoadOfLValue(ThisLValue,
613 SourceLocation()).getScalarVal();
616 // Not in a lambda; just use 'this' from the method.
617 // FIXME: Should we generate a new load for each use of 'this'? The
618 // fast register allocator would be happier...
619 CXXThisValue = CXXABIThisValue;
623 // If any of the arguments have a variably modified type, make sure to
624 // emit the type size.
625 for (FunctionArgList::const_iterator i = Args.begin(), e = Args.end();
627 const VarDecl *VD = *i;
629 // Dig out the type as written from ParmVarDecls; it's unclear whether
630 // the standard (C99 6.9.1p10) requires this, but we're following the
631 // precedent set by gcc.
633 if (const ParmVarDecl *PVD = dyn_cast<ParmVarDecl>(VD))
634 Ty = PVD->getOriginalType();
638 if (Ty->isVariablyModifiedType())
639 EmitVariablyModifiedType(Ty);
641 // Emit a location at the end of the prologue.
642 if (CGDebugInfo *DI = getDebugInfo())
643 DI->EmitLocation(Builder, StartLoc);
646 void CodeGenFunction::EmitFunctionBody(FunctionArgList &Args,
648 if (const CompoundStmt *S = dyn_cast<CompoundStmt>(Body))
649 EmitCompoundStmtWithoutScope(*S);
654 /// Tries to mark the given function nounwind based on the
655 /// non-existence of any throwing calls within it. We believe this is
656 /// lightweight enough to do at -O0.
657 static void TryMarkNoThrow(llvm::Function *F) {
658 // LLVM treats 'nounwind' on a function as part of the type, so we
659 // can't do this on functions that can be overwritten.
660 if (F->mayBeOverridden()) return;
662 for (llvm::Function::iterator FI = F->begin(), FE = F->end(); FI != FE; ++FI)
663 for (llvm::BasicBlock::iterator
664 BI = FI->begin(), BE = FI->end(); BI != BE; ++BI)
665 if (llvm::CallInst *Call = dyn_cast<llvm::CallInst>(&*BI)) {
666 if (!Call->doesNotThrow())
668 } else if (isa<llvm::ResumeInst>(&*BI)) {
671 F->setDoesNotThrow();
674 static void EmitSizedDeallocationFunction(CodeGenFunction &CGF,
675 const FunctionDecl *UnsizedDealloc) {
676 // This is a weak discardable definition of the sized deallocation function.
677 CGF.CurFn->setLinkage(llvm::Function::LinkOnceAnyLinkage);
679 // Call the unsized deallocation function and forward the first argument
681 llvm::Constant *Unsized = CGF.CGM.GetAddrOfFunction(UnsizedDealloc);
682 CGF.Builder.CreateCall(Unsized, &*CGF.CurFn->arg_begin());
685 void CodeGenFunction::GenerateCode(GlobalDecl GD, llvm::Function *Fn,
686 const CGFunctionInfo &FnInfo) {
687 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
689 // Check if we should generate debug info for this function.
690 if (FD->hasAttr<NoDebugAttr>())
691 DebugInfo = NULL; // disable debug info indefinitely for this function
693 FunctionArgList Args;
694 QualType ResTy = FD->getResultType();
697 const CXXMethodDecl *MD;
698 if ((MD = dyn_cast<CXXMethodDecl>(FD)) && MD->isInstance()) {
699 if (CGM.getCXXABI().HasThisReturn(GD))
700 ResTy = MD->getThisType(getContext());
701 CGM.getCXXABI().BuildInstanceFunctionParams(*this, ResTy, Args);
704 for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i)
705 Args.push_back(FD->getParamDecl(i));
707 SourceRange BodyRange;
708 if (Stmt *Body = FD->getBody()) BodyRange = Body->getSourceRange();
709 CurEHLocation = BodyRange.getEnd();
711 // Emit the standard function prologue.
712 StartFunction(GD, ResTy, Fn, FnInfo, Args, BodyRange.getBegin());
714 // Generate the body of the function.
715 if (isa<CXXDestructorDecl>(FD))
716 EmitDestructorBody(Args);
717 else if (isa<CXXConstructorDecl>(FD))
718 EmitConstructorBody(Args);
719 else if (getLangOpts().CUDA &&
720 !CGM.getCodeGenOpts().CUDAIsDevice &&
721 FD->hasAttr<CUDAGlobalAttr>())
722 CGM.getCUDARuntime().EmitDeviceStubBody(*this, Args);
723 else if (isa<CXXConversionDecl>(FD) &&
724 cast<CXXConversionDecl>(FD)->isLambdaToBlockPointerConversion()) {
725 // The lambda conversion to block pointer is special; the semantics can't be
726 // expressed in the AST, so IRGen needs to special-case it.
727 EmitLambdaToBlockPointerBody(Args);
728 } else if (isa<CXXMethodDecl>(FD) &&
729 cast<CXXMethodDecl>(FD)->isLambdaStaticInvoker()) {
730 // The lambda static invoker function is special, because it forwards or
731 // clones the body of the function call operator (but is actually static).
732 EmitLambdaStaticInvokeFunction(cast<CXXMethodDecl>(FD));
733 } else if (FD->isDefaulted() && isa<CXXMethodDecl>(FD) &&
734 (cast<CXXMethodDecl>(FD)->isCopyAssignmentOperator() ||
735 cast<CXXMethodDecl>(FD)->isMoveAssignmentOperator())) {
736 // Implicit copy-assignment gets the same special treatment as implicit
737 // copy-constructors.
738 emitImplicitAssignmentOperatorBody(Args);
739 } else if (Stmt *Body = FD->getBody()) {
740 EmitFunctionBody(Args, Body);
741 } else if (FunctionDecl *UnsizedDealloc =
742 FD->getCorrespondingUnsizedGlobalDeallocationFunction()) {
743 // Global sized deallocation functions get an implicit weak definition if
744 // they don't have an explicit definition.
745 EmitSizedDeallocationFunction(*this, UnsizedDealloc);
747 llvm_unreachable("no definition for emitted function");
749 // C++11 [stmt.return]p2:
750 // Flowing off the end of a function [...] results in undefined behavior in
751 // a value-returning function.
753 // If the '}' that terminates a function is reached, and the value of the
754 // function call is used by the caller, the behavior is undefined.
755 if (getLangOpts().CPlusPlus && !FD->hasImplicitReturnZero() &&
756 !FD->getResultType()->isVoidType() && Builder.GetInsertBlock()) {
758 EmitCheck(Builder.getFalse(), "missing_return",
759 EmitCheckSourceLocation(FD->getLocation()),
760 ArrayRef<llvm::Value *>(), CRK_Unrecoverable);
761 else if (CGM.getCodeGenOpts().OptimizationLevel == 0)
762 Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::trap));
763 Builder.CreateUnreachable();
764 Builder.ClearInsertionPoint();
767 // Emit the standard function epilogue.
768 FinishFunction(BodyRange.getEnd());
770 // If we haven't marked the function nothrow through other means, do
771 // a quick pass now to see if we can.
772 if (!CurFn->doesNotThrow())
773 TryMarkNoThrow(CurFn);
776 /// ContainsLabel - Return true if the statement contains a label in it. If
777 /// this statement is not executed normally, it not containing a label means
778 /// that we can just remove the code.
779 bool CodeGenFunction::ContainsLabel(const Stmt *S, bool IgnoreCaseStmts) {
780 // Null statement, not a label!
781 if (S == 0) return false;
783 // If this is a label, we have to emit the code, consider something like:
784 // if (0) { ... foo: bar(); } goto foo;
786 // TODO: If anyone cared, we could track __label__'s, since we know that you
787 // can't jump to one from outside their declared region.
788 if (isa<LabelStmt>(S))
791 // If this is a case/default statement, and we haven't seen a switch, we have
793 if (isa<SwitchCase>(S) && !IgnoreCaseStmts)
796 // If this is a switch statement, we want to ignore cases below it.
797 if (isa<SwitchStmt>(S))
798 IgnoreCaseStmts = true;
800 // Scan subexpressions for verboten labels.
801 for (Stmt::const_child_range I = S->children(); I; ++I)
802 if (ContainsLabel(*I, IgnoreCaseStmts))
808 /// containsBreak - Return true if the statement contains a break out of it.
809 /// If the statement (recursively) contains a switch or loop with a break
810 /// inside of it, this is fine.
811 bool CodeGenFunction::containsBreak(const Stmt *S) {
812 // Null statement, not a label!
813 if (S == 0) return false;
815 // If this is a switch or loop that defines its own break scope, then we can
816 // include it and anything inside of it.
817 if (isa<SwitchStmt>(S) || isa<WhileStmt>(S) || isa<DoStmt>(S) ||
821 if (isa<BreakStmt>(S))
824 // Scan subexpressions for verboten breaks.
825 for (Stmt::const_child_range I = S->children(); I; ++I)
826 if (containsBreak(*I))
833 /// ConstantFoldsToSimpleInteger - If the specified expression does not fold
834 /// to a constant, or if it does but contains a label, return false. If it
835 /// constant folds return true and set the boolean result in Result.
836 bool CodeGenFunction::ConstantFoldsToSimpleInteger(const Expr *Cond,
838 llvm::APSInt ResultInt;
839 if (!ConstantFoldsToSimpleInteger(Cond, ResultInt))
842 ResultBool = ResultInt.getBoolValue();
846 /// ConstantFoldsToSimpleInteger - If the specified expression does not fold
847 /// to a constant, or if it does but contains a label, return false. If it
848 /// constant folds return true and set the folded value.
849 bool CodeGenFunction::
850 ConstantFoldsToSimpleInteger(const Expr *Cond, llvm::APSInt &ResultInt) {
851 // FIXME: Rename and handle conversion of other evaluatable things
854 if (!Cond->EvaluateAsInt(Int, getContext()))
855 return false; // Not foldable, not integer or not fully evaluatable.
857 if (CodeGenFunction::ContainsLabel(Cond))
858 return false; // Contains a label.
866 /// EmitBranchOnBoolExpr - Emit a branch on a boolean condition (e.g. for an if
867 /// statement) to the specified blocks. Based on the condition, this might try
868 /// to simplify the codegen of the conditional based on the branch.
870 void CodeGenFunction::EmitBranchOnBoolExpr(const Expr *Cond,
871 llvm::BasicBlock *TrueBlock,
872 llvm::BasicBlock *FalseBlock) {
873 Cond = Cond->IgnoreParens();
875 if (const BinaryOperator *CondBOp = dyn_cast<BinaryOperator>(Cond)) {
876 // Handle X && Y in a condition.
877 if (CondBOp->getOpcode() == BO_LAnd) {
878 // If we have "1 && X", simplify the code. "0 && X" would have constant
879 // folded if the case was simple enough.
880 bool ConstantBool = false;
881 if (ConstantFoldsToSimpleInteger(CondBOp->getLHS(), ConstantBool) &&
883 // br(1 && X) -> br(X).
884 return EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock);
887 // If we have "X && 1", simplify the code to use an uncond branch.
888 // "X && 0" would have been constant folded to 0.
889 if (ConstantFoldsToSimpleInteger(CondBOp->getRHS(), ConstantBool) &&
891 // br(X && 1) -> br(X).
892 return EmitBranchOnBoolExpr(CondBOp->getLHS(), TrueBlock, FalseBlock);
895 // Emit the LHS as a conditional. If the LHS conditional is false, we
896 // want to jump to the FalseBlock.
897 llvm::BasicBlock *LHSTrue = createBasicBlock("land.lhs.true");
899 ConditionalEvaluation eval(*this);
900 EmitBranchOnBoolExpr(CondBOp->getLHS(), LHSTrue, FalseBlock);
903 // Any temporaries created here are conditional.
905 EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock);
911 if (CondBOp->getOpcode() == BO_LOr) {
912 // If we have "0 || X", simplify the code. "1 || X" would have constant
913 // folded if the case was simple enough.
914 bool ConstantBool = false;
915 if (ConstantFoldsToSimpleInteger(CondBOp->getLHS(), ConstantBool) &&
917 // br(0 || X) -> br(X).
918 return EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock);
921 // If we have "X || 0", simplify the code to use an uncond branch.
922 // "X || 1" would have been constant folded to 1.
923 if (ConstantFoldsToSimpleInteger(CondBOp->getRHS(), ConstantBool) &&
925 // br(X || 0) -> br(X).
926 return EmitBranchOnBoolExpr(CondBOp->getLHS(), TrueBlock, FalseBlock);
929 // Emit the LHS as a conditional. If the LHS conditional is true, we
930 // want to jump to the TrueBlock.
931 llvm::BasicBlock *LHSFalse = createBasicBlock("lor.lhs.false");
933 ConditionalEvaluation eval(*this);
934 EmitBranchOnBoolExpr(CondBOp->getLHS(), TrueBlock, LHSFalse);
937 // Any temporaries created here are conditional.
939 EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock);
946 if (const UnaryOperator *CondUOp = dyn_cast<UnaryOperator>(Cond)) {
947 // br(!x, t, f) -> br(x, f, t)
948 if (CondUOp->getOpcode() == UO_LNot)
949 return EmitBranchOnBoolExpr(CondUOp->getSubExpr(), FalseBlock, TrueBlock);
952 if (const ConditionalOperator *CondOp = dyn_cast<ConditionalOperator>(Cond)) {
953 // br(c ? x : y, t, f) -> br(c, br(x, t, f), br(y, t, f))
954 llvm::BasicBlock *LHSBlock = createBasicBlock("cond.true");
955 llvm::BasicBlock *RHSBlock = createBasicBlock("cond.false");
957 ConditionalEvaluation cond(*this);
958 EmitBranchOnBoolExpr(CondOp->getCond(), LHSBlock, RHSBlock);
962 EmitBranchOnBoolExpr(CondOp->getLHS(), TrueBlock, FalseBlock);
967 EmitBranchOnBoolExpr(CondOp->getRHS(), TrueBlock, FalseBlock);
973 if (const CXXThrowExpr *Throw = dyn_cast<CXXThrowExpr>(Cond)) {
974 // Conditional operator handling can give us a throw expression as a
975 // condition for a case like:
976 // br(c ? throw x : y, t, f) -> br(c, br(throw x, t, f), br(y, t, f)
978 // br(c, throw x, br(y, t, f))
979 EmitCXXThrowExpr(Throw, /*KeepInsertionPoint*/false);
983 // Emit the code with the fully general case.
984 llvm::Value *CondV = EvaluateExprAsBool(Cond);
985 Builder.CreateCondBr(CondV, TrueBlock, FalseBlock);
988 /// ErrorUnsupported - Print out an error that codegen doesn't support the
989 /// specified stmt yet.
990 void CodeGenFunction::ErrorUnsupported(const Stmt *S, const char *Type) {
991 CGM.ErrorUnsupported(S, Type);
994 /// emitNonZeroVLAInit - Emit the "zero" initialization of a
995 /// variable-length array whose elements have a non-zero bit-pattern.
997 /// \param baseType the inner-most element type of the array
998 /// \param src - a char* pointing to the bit-pattern for a single
999 /// base element of the array
1000 /// \param sizeInChars - the total size of the VLA, in chars
1001 static void emitNonZeroVLAInit(CodeGenFunction &CGF, QualType baseType,
1002 llvm::Value *dest, llvm::Value *src,
1003 llvm::Value *sizeInChars) {
1004 std::pair<CharUnits,CharUnits> baseSizeAndAlign
1005 = CGF.getContext().getTypeInfoInChars(baseType);
1007 CGBuilderTy &Builder = CGF.Builder;
1009 llvm::Value *baseSizeInChars
1010 = llvm::ConstantInt::get(CGF.IntPtrTy, baseSizeAndAlign.first.getQuantity());
1012 llvm::Type *i8p = Builder.getInt8PtrTy();
1014 llvm::Value *begin = Builder.CreateBitCast(dest, i8p, "vla.begin");
1015 llvm::Value *end = Builder.CreateInBoundsGEP(dest, sizeInChars, "vla.end");
1017 llvm::BasicBlock *originBB = CGF.Builder.GetInsertBlock();
1018 llvm::BasicBlock *loopBB = CGF.createBasicBlock("vla-init.loop");
1019 llvm::BasicBlock *contBB = CGF.createBasicBlock("vla-init.cont");
1021 // Make a loop over the VLA. C99 guarantees that the VLA element
1022 // count must be nonzero.
1023 CGF.EmitBlock(loopBB);
1025 llvm::PHINode *cur = Builder.CreatePHI(i8p, 2, "vla.cur");
1026 cur->addIncoming(begin, originBB);
1028 // memcpy the individual element bit-pattern.
1029 Builder.CreateMemCpy(cur, src, baseSizeInChars,
1030 baseSizeAndAlign.second.getQuantity(),
1031 /*volatile*/ false);
1033 // Go to the next element.
1034 llvm::Value *next = Builder.CreateConstInBoundsGEP1_32(cur, 1, "vla.next");
1036 // Leave if that's the end of the VLA.
1037 llvm::Value *done = Builder.CreateICmpEQ(next, end, "vla-init.isdone");
1038 Builder.CreateCondBr(done, contBB, loopBB);
1039 cur->addIncoming(next, loopBB);
1041 CGF.EmitBlock(contBB);
1045 CodeGenFunction::EmitNullInitialization(llvm::Value *DestPtr, QualType Ty) {
1046 // Ignore empty classes in C++.
1047 if (getLangOpts().CPlusPlus) {
1048 if (const RecordType *RT = Ty->getAs<RecordType>()) {
1049 if (cast<CXXRecordDecl>(RT->getDecl())->isEmpty())
1054 // Cast the dest ptr to the appropriate i8 pointer type.
1056 cast<llvm::PointerType>(DestPtr->getType())->getAddressSpace();
1057 llvm::Type *BP = Builder.getInt8PtrTy(DestAS);
1058 if (DestPtr->getType() != BP)
1059 DestPtr = Builder.CreateBitCast(DestPtr, BP);
1061 // Get size and alignment info for this aggregate.
1062 std::pair<CharUnits, CharUnits> TypeInfo =
1063 getContext().getTypeInfoInChars(Ty);
1064 CharUnits Size = TypeInfo.first;
1065 CharUnits Align = TypeInfo.second;
1067 llvm::Value *SizeVal;
1068 const VariableArrayType *vla;
1070 // Don't bother emitting a zero-byte memset.
1071 if (Size.isZero()) {
1072 // But note that getTypeInfo returns 0 for a VLA.
1073 if (const VariableArrayType *vlaType =
1074 dyn_cast_or_null<VariableArrayType>(
1075 getContext().getAsArrayType(Ty))) {
1077 llvm::Value *numElts;
1078 llvm::tie(numElts, eltType) = getVLASize(vlaType);
1081 CharUnits eltSize = getContext().getTypeSizeInChars(eltType);
1082 if (!eltSize.isOne())
1083 SizeVal = Builder.CreateNUWMul(SizeVal, CGM.getSize(eltSize));
1089 SizeVal = CGM.getSize(Size);
1093 // If the type contains a pointer to data member we can't memset it to zero.
1094 // Instead, create a null constant and copy it to the destination.
1095 // TODO: there are other patterns besides zero that we can usefully memset,
1096 // like -1, which happens to be the pattern used by member-pointers.
1097 if (!CGM.getTypes().isZeroInitializable(Ty)) {
1098 // For a VLA, emit a single element, then splat that over the VLA.
1099 if (vla) Ty = getContext().getBaseElementType(vla);
1101 llvm::Constant *NullConstant = CGM.EmitNullConstant(Ty);
1103 llvm::GlobalVariable *NullVariable =
1104 new llvm::GlobalVariable(CGM.getModule(), NullConstant->getType(),
1105 /*isConstant=*/true,
1106 llvm::GlobalVariable::PrivateLinkage,
1107 NullConstant, Twine());
1108 llvm::Value *SrcPtr =
1109 Builder.CreateBitCast(NullVariable, Builder.getInt8PtrTy());
1111 if (vla) return emitNonZeroVLAInit(*this, Ty, DestPtr, SrcPtr, SizeVal);
1113 // Get and call the appropriate llvm.memcpy overload.
1114 Builder.CreateMemCpy(DestPtr, SrcPtr, SizeVal, Align.getQuantity(), false);
1118 // Otherwise, just memset the whole thing to zero. This is legal
1119 // because in LLVM, all default initializers (other than the ones we just
1120 // handled above) are guaranteed to have a bit pattern of all zeros.
1121 Builder.CreateMemSet(DestPtr, Builder.getInt8(0), SizeVal,
1122 Align.getQuantity(), false);
1125 llvm::BlockAddress *CodeGenFunction::GetAddrOfLabel(const LabelDecl *L) {
1126 // Make sure that there is a block for the indirect goto.
1127 if (IndirectBranch == 0)
1128 GetIndirectGotoBlock();
1130 llvm::BasicBlock *BB = getJumpDestForLabel(L).getBlock();
1132 // Make sure the indirect branch includes all of the address-taken blocks.
1133 IndirectBranch->addDestination(BB);
1134 return llvm::BlockAddress::get(CurFn, BB);
1137 llvm::BasicBlock *CodeGenFunction::GetIndirectGotoBlock() {
1138 // If we already made the indirect branch for indirect goto, return its block.
1139 if (IndirectBranch) return IndirectBranch->getParent();
1141 CGBuilderTy TmpBuilder(createBasicBlock("indirectgoto"));
1143 // Create the PHI node that indirect gotos will add entries to.
1144 llvm::Value *DestVal = TmpBuilder.CreatePHI(Int8PtrTy, 0,
1145 "indirect.goto.dest");
1147 // Create the indirect branch instruction.
1148 IndirectBranch = TmpBuilder.CreateIndirectBr(DestVal);
1149 return IndirectBranch->getParent();
1152 /// Computes the length of an array in elements, as well as the base
1153 /// element type and a properly-typed first element pointer.
1154 llvm::Value *CodeGenFunction::emitArrayLength(const ArrayType *origArrayType,
1156 llvm::Value *&addr) {
1157 const ArrayType *arrayType = origArrayType;
1159 // If it's a VLA, we have to load the stored size. Note that
1160 // this is the size of the VLA in bytes, not its size in elements.
1161 llvm::Value *numVLAElements = 0;
1162 if (isa<VariableArrayType>(arrayType)) {
1163 numVLAElements = getVLASize(cast<VariableArrayType>(arrayType)).first;
1165 // Walk into all VLAs. This doesn't require changes to addr,
1166 // which has type T* where T is the first non-VLA element type.
1168 QualType elementType = arrayType->getElementType();
1169 arrayType = getContext().getAsArrayType(elementType);
1171 // If we only have VLA components, 'addr' requires no adjustment.
1173 baseType = elementType;
1174 return numVLAElements;
1176 } while (isa<VariableArrayType>(arrayType));
1178 // We get out here only if we find a constant array type
1182 // We have some number of constant-length arrays, so addr should
1183 // have LLVM type [M x [N x [...]]]*. Build a GEP that walks
1184 // down to the first element of addr.
1185 SmallVector<llvm::Value*, 8> gepIndices;
1187 // GEP down to the array type.
1188 llvm::ConstantInt *zero = Builder.getInt32(0);
1189 gepIndices.push_back(zero);
1191 uint64_t countFromCLAs = 1;
1194 llvm::ArrayType *llvmArrayType =
1195 dyn_cast<llvm::ArrayType>(
1196 cast<llvm::PointerType>(addr->getType())->getElementType());
1197 while (llvmArrayType) {
1198 assert(isa<ConstantArrayType>(arrayType));
1199 assert(cast<ConstantArrayType>(arrayType)->getSize().getZExtValue()
1200 == llvmArrayType->getNumElements());
1202 gepIndices.push_back(zero);
1203 countFromCLAs *= llvmArrayType->getNumElements();
1204 eltType = arrayType->getElementType();
1207 dyn_cast<llvm::ArrayType>(llvmArrayType->getElementType());
1208 arrayType = getContext().getAsArrayType(arrayType->getElementType());
1209 assert((!llvmArrayType || arrayType) &&
1210 "LLVM and Clang types are out-of-synch");
1214 // From this point onwards, the Clang array type has been emitted
1215 // as some other type (probably a packed struct). Compute the array
1216 // size, and just emit the 'begin' expression as a bitcast.
1219 cast<ConstantArrayType>(arrayType)->getSize().getZExtValue();
1220 eltType = arrayType->getElementType();
1221 arrayType = getContext().getAsArrayType(eltType);
1224 unsigned AddressSpace = addr->getType()->getPointerAddressSpace();
1225 llvm::Type *BaseType = ConvertType(eltType)->getPointerTo(AddressSpace);
1226 addr = Builder.CreateBitCast(addr, BaseType, "array.begin");
1228 // Create the actual GEP.
1229 addr = Builder.CreateInBoundsGEP(addr, gepIndices, "array.begin");
1234 llvm::Value *numElements
1235 = llvm::ConstantInt::get(SizeTy, countFromCLAs);
1237 // If we had any VLA dimensions, factor them in.
1239 numElements = Builder.CreateNUWMul(numVLAElements, numElements);
1244 std::pair<llvm::Value*, QualType>
1245 CodeGenFunction::getVLASize(QualType type) {
1246 const VariableArrayType *vla = getContext().getAsVariableArrayType(type);
1247 assert(vla && "type was not a variable array type!");
1248 return getVLASize(vla);
1251 std::pair<llvm::Value*, QualType>
1252 CodeGenFunction::getVLASize(const VariableArrayType *type) {
1253 // The number of elements so far; always size_t.
1254 llvm::Value *numElements = 0;
1256 QualType elementType;
1258 elementType = type->getElementType();
1259 llvm::Value *vlaSize = VLASizeMap[type->getSizeExpr()];
1260 assert(vlaSize && "no size for VLA!");
1261 assert(vlaSize->getType() == SizeTy);
1264 numElements = vlaSize;
1266 // It's undefined behavior if this wraps around, so mark it that way.
1267 // FIXME: Teach -fcatch-undefined-behavior to trap this.
1268 numElements = Builder.CreateNUWMul(numElements, vlaSize);
1270 } while ((type = getContext().getAsVariableArrayType(elementType)));
1272 return std::pair<llvm::Value*,QualType>(numElements, elementType);
1275 void CodeGenFunction::EmitVariablyModifiedType(QualType type) {
1276 assert(type->isVariablyModifiedType() &&
1277 "Must pass variably modified type to EmitVLASizes!");
1279 EnsureInsertPoint();
1281 // We're going to walk down into the type and look for VLA
1284 assert(type->isVariablyModifiedType());
1286 const Type *ty = type.getTypePtr();
1287 switch (ty->getTypeClass()) {
1289 #define TYPE(Class, Base)
1290 #define ABSTRACT_TYPE(Class, Base)
1291 #define NON_CANONICAL_TYPE(Class, Base)
1292 #define DEPENDENT_TYPE(Class, Base) case Type::Class:
1293 #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base)
1294 #include "clang/AST/TypeNodes.def"
1295 llvm_unreachable("unexpected dependent type!");
1297 // These types are never variably-modified.
1301 case Type::ExtVector:
1304 case Type::Elaborated:
1305 case Type::TemplateSpecialization:
1306 case Type::ObjCObject:
1307 case Type::ObjCInterface:
1308 case Type::ObjCObjectPointer:
1309 llvm_unreachable("type class is never variably-modified!");
1312 type = cast<DecayedType>(ty)->getPointeeType();
1316 type = cast<PointerType>(ty)->getPointeeType();
1319 case Type::BlockPointer:
1320 type = cast<BlockPointerType>(ty)->getPointeeType();
1323 case Type::LValueReference:
1324 case Type::RValueReference:
1325 type = cast<ReferenceType>(ty)->getPointeeType();
1328 case Type::MemberPointer:
1329 type = cast<MemberPointerType>(ty)->getPointeeType();
1332 case Type::ConstantArray:
1333 case Type::IncompleteArray:
1334 // Losing element qualification here is fine.
1335 type = cast<ArrayType>(ty)->getElementType();
1338 case Type::VariableArray: {
1339 // Losing element qualification here is fine.
1340 const VariableArrayType *vat = cast<VariableArrayType>(ty);
1342 // Unknown size indication requires no size computation.
1343 // Otherwise, evaluate and record it.
1344 if (const Expr *size = vat->getSizeExpr()) {
1345 // It's possible that we might have emitted this already,
1346 // e.g. with a typedef and a pointer to it.
1347 llvm::Value *&entry = VLASizeMap[size];
1349 llvm::Value *Size = EmitScalarExpr(size);
1352 // If the size is an expression that is not an integer constant
1353 // expression [...] each time it is evaluated it shall have a value
1354 // greater than zero.
1355 if (SanOpts->VLABound &&
1356 size->getType()->isSignedIntegerType()) {
1357 llvm::Value *Zero = llvm::Constant::getNullValue(Size->getType());
1358 llvm::Constant *StaticArgs[] = {
1359 EmitCheckSourceLocation(size->getLocStart()),
1360 EmitCheckTypeDescriptor(size->getType())
1362 EmitCheck(Builder.CreateICmpSGT(Size, Zero),
1363 "vla_bound_not_positive", StaticArgs, Size,
1367 // Always zexting here would be wrong if it weren't
1368 // undefined behavior to have a negative bound.
1369 entry = Builder.CreateIntCast(Size, SizeTy, /*signed*/ false);
1372 type = vat->getElementType();
1376 case Type::FunctionProto:
1377 case Type::FunctionNoProto:
1378 type = cast<FunctionType>(ty)->getResultType();
1383 case Type::UnaryTransform:
1384 case Type::Attributed:
1385 case Type::SubstTemplateTypeParm:
1386 case Type::PackExpansion:
1387 // Keep walking after single level desugaring.
1388 type = type.getSingleStepDesugaredType(getContext());
1392 case Type::Decltype:
1394 // Stop walking: nothing to do.
1397 case Type::TypeOfExpr:
1398 // Stop walking: emit typeof expression.
1399 EmitIgnoredExpr(cast<TypeOfExprType>(ty)->getUnderlyingExpr());
1403 type = cast<AtomicType>(ty)->getValueType();
1406 } while (type->isVariablyModifiedType());
1409 llvm::Value* CodeGenFunction::EmitVAListRef(const Expr* E) {
1410 if (getContext().getBuiltinVaListType()->isArrayType())
1411 return EmitScalarExpr(E);
1412 return EmitLValue(E).getAddress();
1415 void CodeGenFunction::EmitDeclRefExprDbgValue(const DeclRefExpr *E,
1416 llvm::Constant *Init) {
1417 assert (Init && "Invalid DeclRefExpr initializer!");
1418 if (CGDebugInfo *Dbg = getDebugInfo())
1419 if (CGM.getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo)
1420 Dbg->EmitGlobalVariable(E->getDecl(), Init);
1423 CodeGenFunction::PeepholeProtection
1424 CodeGenFunction::protectFromPeepholes(RValue rvalue) {
1425 // At the moment, the only aggressive peephole we do in IR gen
1426 // is trunc(zext) folding, but if we add more, we can easily
1427 // extend this protection.
1429 if (!rvalue.isScalar()) return PeepholeProtection();
1430 llvm::Value *value = rvalue.getScalarVal();
1431 if (!isa<llvm::ZExtInst>(value)) return PeepholeProtection();
1433 // Just make an extra bitcast.
1434 assert(HaveInsertPoint());
1435 llvm::Instruction *inst = new llvm::BitCastInst(value, value->getType(), "",
1436 Builder.GetInsertBlock());
1438 PeepholeProtection protection;
1439 protection.Inst = inst;
1443 void CodeGenFunction::unprotectFromPeepholes(PeepholeProtection protection) {
1444 if (!protection.Inst) return;
1446 // In theory, we could try to duplicate the peepholes now, but whatever.
1447 protection.Inst->eraseFromParent();
1450 llvm::Value *CodeGenFunction::EmitAnnotationCall(llvm::Value *AnnotationFn,
1451 llvm::Value *AnnotatedVal,
1452 StringRef AnnotationStr,
1453 SourceLocation Location) {
1454 llvm::Value *Args[4] = {
1456 Builder.CreateBitCast(CGM.EmitAnnotationString(AnnotationStr), Int8PtrTy),
1457 Builder.CreateBitCast(CGM.EmitAnnotationUnit(Location), Int8PtrTy),
1458 CGM.EmitAnnotationLineNo(Location)
1460 return Builder.CreateCall(AnnotationFn, Args);
1463 void CodeGenFunction::EmitVarAnnotations(const VarDecl *D, llvm::Value *V) {
1464 assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute");
1465 // FIXME We create a new bitcast for every annotation because that's what
1466 // llvm-gcc was doing.
1467 for (specific_attr_iterator<AnnotateAttr>
1468 ai = D->specific_attr_begin<AnnotateAttr>(),
1469 ae = D->specific_attr_end<AnnotateAttr>(); ai != ae; ++ai)
1470 EmitAnnotationCall(CGM.getIntrinsic(llvm::Intrinsic::var_annotation),
1471 Builder.CreateBitCast(V, CGM.Int8PtrTy, V->getName()),
1472 (*ai)->getAnnotation(), D->getLocation());
1475 llvm::Value *CodeGenFunction::EmitFieldAnnotations(const FieldDecl *D,
1477 assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute");
1478 llvm::Type *VTy = V->getType();
1479 llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::ptr_annotation,
1482 for (specific_attr_iterator<AnnotateAttr>
1483 ai = D->specific_attr_begin<AnnotateAttr>(),
1484 ae = D->specific_attr_end<AnnotateAttr>(); ai != ae; ++ai) {
1485 // FIXME Always emit the cast inst so we can differentiate between
1486 // annotation on the first field of a struct and annotation on the struct
1488 if (VTy != CGM.Int8PtrTy)
1489 V = Builder.Insert(new llvm::BitCastInst(V, CGM.Int8PtrTy));
1490 V = EmitAnnotationCall(F, V, (*ai)->getAnnotation(), D->getLocation());
1491 V = Builder.CreateBitCast(V, VTy);
1497 CodeGenFunction::CGCapturedStmtInfo::~CGCapturedStmtInfo() { }