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 "clang/AST/ASTContext.h"
20 #include "clang/AST/Decl.h"
21 #include "clang/AST/DeclCXX.h"
22 #include "clang/AST/StmtCXX.h"
23 #include "clang/Basic/OpenCL.h"
24 #include "clang/Basic/TargetInfo.h"
25 #include "clang/Frontend/CodeGenOptions.h"
26 #include "llvm/IR/DataLayout.h"
27 #include "llvm/IR/Intrinsics.h"
28 #include "llvm/IR/MDBuilder.h"
29 #include "llvm/IR/Operator.h"
30 using namespace clang;
31 using namespace CodeGen;
33 CodeGenFunction::CodeGenFunction(CodeGenModule &cgm, bool suppressNewContext)
34 : CodeGenTypeCache(cgm), CGM(cgm),
35 Target(CGM.getContext().getTargetInfo()),
36 Builder(cgm.getModule().getContext()),
37 SanitizePerformTypeCheck(CGM.getSanOpts().Null |
38 CGM.getSanOpts().Alignment |
39 CGM.getSanOpts().ObjectSize |
40 CGM.getSanOpts().Vptr),
41 SanOpts(&CGM.getSanOpts()),
42 AutoreleaseResult(false), BlockInfo(0), BlockPointer(0),
43 LambdaThisCaptureField(0), NormalCleanupDest(0), NextCleanupDestIndex(1),
44 FirstBlockInfo(0), EHResumeBlock(0), ExceptionSlot(0), EHSelectorSlot(0),
45 DebugInfo(0), DisableDebugInfo(false), CalleeWithThisReturn(0),
46 DidCallStackSave(false),
47 IndirectBranch(0), SwitchInsn(0), CaseRangeBlock(0), UnreachableBlock(0),
48 CXXABIThisDecl(0), CXXABIThisValue(0), CXXThisValue(0),
49 CXXStructorImplicitParamDecl(0), CXXStructorImplicitParamValue(0),
50 OutermostConditional(0), CurLexicalScope(0), TerminateLandingPad(0),
51 TerminateHandler(0), TrapBB(0) {
52 if (!suppressNewContext)
53 CGM.getCXXABI().getMangleContext().startNewFunction();
55 llvm::FastMathFlags FMF;
56 if (CGM.getLangOpts().FastMath)
57 FMF.setUnsafeAlgebra();
58 if (CGM.getLangOpts().FiniteMathOnly) {
62 Builder.SetFastMathFlags(FMF);
65 CodeGenFunction::~CodeGenFunction() {
66 // If there are any unclaimed block infos, go ahead and destroy them
67 // now. This can happen if IR-gen gets clever and skips evaluating
70 destroyBlockInfos(FirstBlockInfo);
74 llvm::Type *CodeGenFunction::ConvertTypeForMem(QualType T) {
75 return CGM.getTypes().ConvertTypeForMem(T);
78 llvm::Type *CodeGenFunction::ConvertType(QualType T) {
79 return CGM.getTypes().ConvertType(T);
82 TypeEvaluationKind CodeGenFunction::getEvaluationKind(QualType type) {
83 type = type.getCanonicalType();
85 switch (type->getTypeClass()) {
86 #define TYPE(name, parent)
87 #define ABSTRACT_TYPE(name, parent)
88 #define NON_CANONICAL_TYPE(name, parent) case Type::name:
89 #define DEPENDENT_TYPE(name, parent) case Type::name:
90 #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(name, parent) case Type::name:
91 #include "clang/AST/TypeNodes.def"
92 llvm_unreachable("non-canonical or dependent type in IR-generation");
94 // Various scalar types.
97 case Type::BlockPointer:
98 case Type::LValueReference:
99 case Type::RValueReference:
100 case Type::MemberPointer:
102 case Type::ExtVector:
103 case Type::FunctionProto:
104 case Type::FunctionNoProto:
106 case Type::ObjCObjectPointer:
113 // Arrays, records, and Objective-C objects.
114 case Type::ConstantArray:
115 case Type::IncompleteArray:
116 case Type::VariableArray:
118 case Type::ObjCObject:
119 case Type::ObjCInterface:
120 return TEK_Aggregate;
122 // We operate on atomic values according to their underlying type.
124 type = cast<AtomicType>(type)->getValueType();
127 llvm_unreachable("unknown type kind!");
131 void CodeGenFunction::EmitReturnBlock() {
132 // For cleanliness, we try to avoid emitting the return block for
134 llvm::BasicBlock *CurBB = Builder.GetInsertBlock();
137 assert(!CurBB->getTerminator() && "Unexpected terminated block.");
139 // We have a valid insert point, reuse it if it is empty or there are no
140 // explicit jumps to the return block.
141 if (CurBB->empty() || ReturnBlock.getBlock()->use_empty()) {
142 ReturnBlock.getBlock()->replaceAllUsesWith(CurBB);
143 delete ReturnBlock.getBlock();
145 EmitBlock(ReturnBlock.getBlock());
149 // Otherwise, if the return block is the target of a single direct
150 // branch then we can just put the code in that block instead. This
151 // cleans up functions which started with a unified return block.
152 if (ReturnBlock.getBlock()->hasOneUse()) {
153 llvm::BranchInst *BI =
154 dyn_cast<llvm::BranchInst>(*ReturnBlock.getBlock()->use_begin());
155 if (BI && BI->isUnconditional() &&
156 BI->getSuccessor(0) == ReturnBlock.getBlock()) {
157 // Reset insertion point, including debug location, and delete the
158 // branch. This is really subtle and only works because the next change
159 // in location will hit the caching in CGDebugInfo::EmitLocation and not
161 Builder.SetCurrentDebugLocation(BI->getDebugLoc());
162 Builder.SetInsertPoint(BI->getParent());
163 BI->eraseFromParent();
164 delete ReturnBlock.getBlock();
169 // FIXME: We are at an unreachable point, there is no reason to emit the block
170 // unless it has uses. However, we still need a place to put the debug
171 // region.end for now.
173 EmitBlock(ReturnBlock.getBlock());
176 static void EmitIfUsed(CodeGenFunction &CGF, llvm::BasicBlock *BB) {
178 if (!BB->use_empty())
179 return CGF.CurFn->getBasicBlockList().push_back(BB);
183 void CodeGenFunction::FinishFunction(SourceLocation EndLoc) {
184 assert(BreakContinueStack.empty() &&
185 "mismatched push/pop in break/continue stack!");
187 if (CGDebugInfo *DI = getDebugInfo())
188 DI->EmitLocation(Builder, EndLoc);
190 // Pop any cleanups that might have been associated with the
191 // parameters. Do this in whatever block we're currently in; it's
192 // important to do this before we enter the return block or return
193 // edges will be *really* confused.
194 if (EHStack.stable_begin() != PrologueCleanupDepth)
195 PopCleanupBlocks(PrologueCleanupDepth);
197 // Emit function epilog (to return).
200 if (ShouldInstrumentFunction())
201 EmitFunctionInstrumentation("__cyg_profile_func_exit");
203 // Emit debug descriptor for function end.
204 if (CGDebugInfo *DI = getDebugInfo()) {
205 DI->EmitFunctionEnd(Builder);
208 EmitFunctionEpilog(*CurFnInfo);
209 EmitEndEHSpec(CurCodeDecl);
211 assert(EHStack.empty() &&
212 "did not remove all scopes from cleanup stack!");
214 // If someone did an indirect goto, emit the indirect goto block at the end of
216 if (IndirectBranch) {
217 EmitBlock(IndirectBranch->getParent());
218 Builder.ClearInsertionPoint();
221 // Remove the AllocaInsertPt instruction, which is just a convenience for us.
222 llvm::Instruction *Ptr = AllocaInsertPt;
224 Ptr->eraseFromParent();
226 // If someone took the address of a label but never did an indirect goto, we
227 // made a zero entry PHI node, which is illegal, zap it now.
228 if (IndirectBranch) {
229 llvm::PHINode *PN = cast<llvm::PHINode>(IndirectBranch->getAddress());
230 if (PN->getNumIncomingValues() == 0) {
231 PN->replaceAllUsesWith(llvm::UndefValue::get(PN->getType()));
232 PN->eraseFromParent();
236 EmitIfUsed(*this, EHResumeBlock);
237 EmitIfUsed(*this, TerminateLandingPad);
238 EmitIfUsed(*this, TerminateHandler);
239 EmitIfUsed(*this, UnreachableBlock);
241 if (CGM.getCodeGenOpts().EmitDeclMetadata)
245 /// ShouldInstrumentFunction - Return true if the current function should be
246 /// instrumented with __cyg_profile_func_* calls
247 bool CodeGenFunction::ShouldInstrumentFunction() {
248 if (!CGM.getCodeGenOpts().InstrumentFunctions)
250 if (!CurFuncDecl || CurFuncDecl->hasAttr<NoInstrumentFunctionAttr>())
255 /// EmitFunctionInstrumentation - Emit LLVM code to call the specified
256 /// instrumentation function with the current function and the call site, if
257 /// function instrumentation is enabled.
258 void CodeGenFunction::EmitFunctionInstrumentation(const char *Fn) {
259 // void __cyg_profile_func_{enter,exit} (void *this_fn, void *call_site);
260 llvm::PointerType *PointerTy = Int8PtrTy;
261 llvm::Type *ProfileFuncArgs[] = { PointerTy, PointerTy };
262 llvm::FunctionType *FunctionTy =
263 llvm::FunctionType::get(VoidTy, ProfileFuncArgs, false);
265 llvm::Constant *F = CGM.CreateRuntimeFunction(FunctionTy, Fn);
266 llvm::CallInst *CallSite = Builder.CreateCall(
267 CGM.getIntrinsic(llvm::Intrinsic::returnaddress),
268 llvm::ConstantInt::get(Int32Ty, 0),
271 llvm::Value *args[] = {
272 llvm::ConstantExpr::getBitCast(CurFn, PointerTy),
276 EmitNounwindRuntimeCall(F, args);
279 void CodeGenFunction::EmitMCountInstrumentation() {
280 llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
282 llvm::Constant *MCountFn = CGM.CreateRuntimeFunction(FTy,
283 Target.getMCountName());
284 EmitNounwindRuntimeCall(MCountFn);
287 // OpenCL v1.2 s5.6.4.6 allows the compiler to store kernel argument
288 // information in the program executable. The argument information stored
289 // includes the argument name, its type, the address and access qualifiers used.
290 static void GenOpenCLArgMetadata(const FunctionDecl *FD, llvm::Function *Fn,
291 CodeGenModule &CGM,llvm::LLVMContext &Context,
292 SmallVector <llvm::Value*, 5> &kernelMDArgs,
293 CGBuilderTy& Builder, ASTContext &ASTCtx) {
294 // Create MDNodes that represent the kernel arg metadata.
295 // Each MDNode is a list in the form of "key", N number of values which is
296 // the same number of values as their are kernel arguments.
298 // MDNode for the kernel argument address space qualifiers.
299 SmallVector<llvm::Value*, 8> addressQuals;
300 addressQuals.push_back(llvm::MDString::get(Context, "kernel_arg_addr_space"));
302 // MDNode for the kernel argument access qualifiers (images only).
303 SmallVector<llvm::Value*, 8> accessQuals;
304 accessQuals.push_back(llvm::MDString::get(Context, "kernel_arg_access_qual"));
306 // MDNode for the kernel argument type names.
307 SmallVector<llvm::Value*, 8> argTypeNames;
308 argTypeNames.push_back(llvm::MDString::get(Context, "kernel_arg_type"));
310 // MDNode for the kernel argument type qualifiers.
311 SmallVector<llvm::Value*, 8> argTypeQuals;
312 argTypeQuals.push_back(llvm::MDString::get(Context, "kernel_arg_type_qual"));
314 // MDNode for the kernel argument names.
315 SmallVector<llvm::Value*, 8> argNames;
316 argNames.push_back(llvm::MDString::get(Context, "kernel_arg_name"));
318 for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i) {
319 const ParmVarDecl *parm = FD->getParamDecl(i);
320 QualType ty = parm->getType();
321 std::string typeQuals;
323 if (ty->isPointerType()) {
324 QualType pointeeTy = ty->getPointeeType();
326 // Get address qualifier.
327 addressQuals.push_back(Builder.getInt32(ASTCtx.getTargetAddressSpace(
328 pointeeTy.getAddressSpace())));
330 // Get argument type name.
331 std::string typeName = pointeeTy.getUnqualifiedType().getAsString() + "*";
333 // Turn "unsigned type" to "utype"
334 std::string::size_type pos = typeName.find("unsigned");
335 if (pos != std::string::npos)
336 typeName.erase(pos+1, 8);
338 argTypeNames.push_back(llvm::MDString::get(Context, typeName));
340 // Get argument type qualifiers:
341 if (ty.isRestrictQualified())
342 typeQuals = "restrict";
343 if (pointeeTy.isConstQualified() ||
344 (pointeeTy.getAddressSpace() == LangAS::opencl_constant))
345 typeQuals += typeQuals.empty() ? "const" : " const";
346 if (pointeeTy.isVolatileQualified())
347 typeQuals += typeQuals.empty() ? "volatile" : " volatile";
349 addressQuals.push_back(Builder.getInt32(0));
351 // Get argument type name.
352 std::string typeName = ty.getUnqualifiedType().getAsString();
354 // Turn "unsigned type" to "utype"
355 std::string::size_type pos = typeName.find("unsigned");
356 if (pos != std::string::npos)
357 typeName.erase(pos+1, 8);
359 argTypeNames.push_back(llvm::MDString::get(Context, typeName));
361 // Get argument type qualifiers:
362 if (ty.isConstQualified())
364 if (ty.isVolatileQualified())
365 typeQuals += typeQuals.empty() ? "volatile" : " volatile";
368 argTypeQuals.push_back(llvm::MDString::get(Context, typeQuals));
370 // Get image access qualifier:
371 if (ty->isImageType()) {
372 if (parm->hasAttr<OpenCLImageAccessAttr>() &&
373 parm->getAttr<OpenCLImageAccessAttr>()->getAccess() == CLIA_write_only)
374 accessQuals.push_back(llvm::MDString::get(Context, "write_only"));
376 accessQuals.push_back(llvm::MDString::get(Context, "read_only"));
378 accessQuals.push_back(llvm::MDString::get(Context, "none"));
380 // Get argument name.
381 argNames.push_back(llvm::MDString::get(Context, parm->getName()));
384 kernelMDArgs.push_back(llvm::MDNode::get(Context, addressQuals));
385 kernelMDArgs.push_back(llvm::MDNode::get(Context, accessQuals));
386 kernelMDArgs.push_back(llvm::MDNode::get(Context, argTypeNames));
387 kernelMDArgs.push_back(llvm::MDNode::get(Context, argTypeQuals));
388 kernelMDArgs.push_back(llvm::MDNode::get(Context, argNames));
391 void CodeGenFunction::EmitOpenCLKernelMetadata(const FunctionDecl *FD,
394 if (!FD->hasAttr<OpenCLKernelAttr>())
397 llvm::LLVMContext &Context = getLLVMContext();
399 SmallVector <llvm::Value*, 5> kernelMDArgs;
400 kernelMDArgs.push_back(Fn);
402 if (CGM.getCodeGenOpts().EmitOpenCLArgMetadata)
403 GenOpenCLArgMetadata(FD, Fn, CGM, Context, kernelMDArgs,
404 Builder, getContext());
406 if (FD->hasAttr<VecTypeHintAttr>()) {
407 VecTypeHintAttr *attr = FD->getAttr<VecTypeHintAttr>();
408 QualType hintQTy = attr->getTypeHint();
409 const ExtVectorType *hintEltQTy = hintQTy->getAs<ExtVectorType>();
410 bool isSignedInteger =
411 hintQTy->isSignedIntegerType() ||
412 (hintEltQTy && hintEltQTy->getElementType()->isSignedIntegerType());
413 llvm::Value *attrMDArgs[] = {
414 llvm::MDString::get(Context, "vec_type_hint"),
415 llvm::UndefValue::get(CGM.getTypes().ConvertType(attr->getTypeHint())),
416 llvm::ConstantInt::get(
417 llvm::IntegerType::get(Context, 32),
418 llvm::APInt(32, (uint64_t)(isSignedInteger ? 1 : 0)))
420 kernelMDArgs.push_back(llvm::MDNode::get(Context, attrMDArgs));
423 if (FD->hasAttr<WorkGroupSizeHintAttr>()) {
424 WorkGroupSizeHintAttr *attr = FD->getAttr<WorkGroupSizeHintAttr>();
425 llvm::Value *attrMDArgs[] = {
426 llvm::MDString::get(Context, "work_group_size_hint"),
427 Builder.getInt32(attr->getXDim()),
428 Builder.getInt32(attr->getYDim()),
429 Builder.getInt32(attr->getZDim())
431 kernelMDArgs.push_back(llvm::MDNode::get(Context, attrMDArgs));
434 if (FD->hasAttr<ReqdWorkGroupSizeAttr>()) {
435 ReqdWorkGroupSizeAttr *attr = FD->getAttr<ReqdWorkGroupSizeAttr>();
436 llvm::Value *attrMDArgs[] = {
437 llvm::MDString::get(Context, "reqd_work_group_size"),
438 Builder.getInt32(attr->getXDim()),
439 Builder.getInt32(attr->getYDim()),
440 Builder.getInt32(attr->getZDim())
442 kernelMDArgs.push_back(llvm::MDNode::get(Context, attrMDArgs));
445 llvm::MDNode *kernelMDNode = llvm::MDNode::get(Context, kernelMDArgs);
446 llvm::NamedMDNode *OpenCLKernelMetadata =
447 CGM.getModule().getOrInsertNamedMetadata("opencl.kernels");
448 OpenCLKernelMetadata->addOperand(kernelMDNode);
451 void CodeGenFunction::StartFunction(GlobalDecl GD, QualType RetTy,
453 const CGFunctionInfo &FnInfo,
454 const FunctionArgList &Args,
455 SourceLocation StartLoc) {
456 const Decl *D = GD.getDecl();
458 DidCallStackSave = false;
459 CurCodeDecl = CurFuncDecl = D;
463 assert(CurFn->isDeclaration() && "Function already has body?");
465 if (CGM.getSanitizerBlacklist().isIn(*Fn)) {
466 SanOpts = &SanitizerOptions::Disabled;
467 SanitizePerformTypeCheck = false;
470 // Pass inline keyword to optimizer if it appears explicitly on any
472 if (!CGM.getCodeGenOpts().NoInline)
473 if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D))
474 for (FunctionDecl::redecl_iterator RI = FD->redecls_begin(),
475 RE = FD->redecls_end(); RI != RE; ++RI)
476 if (RI->isInlineSpecified()) {
477 Fn->addFnAttr(llvm::Attribute::InlineHint);
481 if (getLangOpts().OpenCL) {
482 // Add metadata for a kernel function.
483 if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D))
484 EmitOpenCLKernelMetadata(FD, Fn);
487 llvm::BasicBlock *EntryBB = createBasicBlock("entry", CurFn);
489 // Create a marker to make it easy to insert allocas into the entryblock
490 // later. Don't create this with the builder, because we don't want it
492 llvm::Value *Undef = llvm::UndefValue::get(Int32Ty);
493 AllocaInsertPt = new llvm::BitCastInst(Undef, Int32Ty, "", EntryBB);
494 if (Builder.isNamePreserving())
495 AllocaInsertPt->setName("allocapt");
497 ReturnBlock = getJumpDestInCurrentScope("return");
499 Builder.SetInsertPoint(EntryBB);
501 // Emit subprogram debug descriptor.
502 if (CGDebugInfo *DI = getDebugInfo()) {
503 SmallVector<QualType, 16> ArgTypes;
504 for (FunctionArgList::const_iterator i = Args.begin(), e = Args.end();
506 ArgTypes.push_back((*i)->getType());
510 getContext().getFunctionType(RetTy, ArgTypes,
511 FunctionProtoType::ExtProtoInfo());
513 DI->setLocation(StartLoc);
514 DI->EmitFunctionStart(GD, FnType, CurFn, Builder);
517 if (ShouldInstrumentFunction())
518 EmitFunctionInstrumentation("__cyg_profile_func_enter");
520 if (CGM.getCodeGenOpts().InstrumentForProfiling)
521 EmitMCountInstrumentation();
523 if (RetTy->isVoidType()) {
524 // Void type; nothing to return.
526 } else if (CurFnInfo->getReturnInfo().getKind() == ABIArgInfo::Indirect &&
527 !hasScalarEvaluationKind(CurFnInfo->getReturnType())) {
528 // Indirect aggregate return; emit returned value directly into sret slot.
529 // This reduces code size, and affects correctness in C++.
530 ReturnValue = CurFn->arg_begin();
532 ReturnValue = CreateIRTemp(RetTy, "retval");
534 // Tell the epilog emitter to autorelease the result. We do this
535 // now so that various specialized functions can suppress it
536 // during their IR-generation.
537 if (getLangOpts().ObjCAutoRefCount &&
538 !CurFnInfo->isReturnsRetained() &&
539 RetTy->isObjCRetainableType())
540 AutoreleaseResult = true;
543 EmitStartEHSpec(CurCodeDecl);
545 PrologueCleanupDepth = EHStack.stable_begin();
546 EmitFunctionProlog(*CurFnInfo, CurFn, Args);
548 if (D && isa<CXXMethodDecl>(D) && cast<CXXMethodDecl>(D)->isInstance()) {
549 CGM.getCXXABI().EmitInstanceFunctionProlog(*this);
550 const CXXMethodDecl *MD = cast<CXXMethodDecl>(D);
551 if (MD->getParent()->isLambda() &&
552 MD->getOverloadedOperator() == OO_Call) {
553 // We're in a lambda; figure out the captures.
554 MD->getParent()->getCaptureFields(LambdaCaptureFields,
555 LambdaThisCaptureField);
556 if (LambdaThisCaptureField) {
557 // If this lambda captures this, load it.
558 QualType LambdaTagType =
559 getContext().getTagDeclType(LambdaThisCaptureField->getParent());
560 LValue LambdaLV = MakeNaturalAlignAddrLValue(CXXABIThisValue,
562 LValue ThisLValue = EmitLValueForField(LambdaLV,
563 LambdaThisCaptureField);
564 CXXThisValue = EmitLoadOfLValue(ThisLValue).getScalarVal();
567 // Not in a lambda; just use 'this' from the method.
568 // FIXME: Should we generate a new load for each use of 'this'? The
569 // fast register allocator would be happier...
570 CXXThisValue = CXXABIThisValue;
574 // If any of the arguments have a variably modified type, make sure to
575 // emit the type size.
576 for (FunctionArgList::const_iterator i = Args.begin(), e = Args.end();
578 const VarDecl *VD = *i;
580 // Dig out the type as written from ParmVarDecls; it's unclear whether
581 // the standard (C99 6.9.1p10) requires this, but we're following the
582 // precedent set by gcc.
584 if (const ParmVarDecl *PVD = dyn_cast<ParmVarDecl>(VD))
585 Ty = PVD->getOriginalType();
589 if (Ty->isVariablyModifiedType())
590 EmitVariablyModifiedType(Ty);
592 // Emit a location at the end of the prologue.
593 if (CGDebugInfo *DI = getDebugInfo())
594 DI->EmitLocation(Builder, StartLoc);
597 void CodeGenFunction::EmitFunctionBody(FunctionArgList &Args) {
598 const FunctionDecl *FD = cast<FunctionDecl>(CurGD.getDecl());
599 assert(FD->getBody());
600 if (const CompoundStmt *S = dyn_cast<CompoundStmt>(FD->getBody()))
601 EmitCompoundStmtWithoutScope(*S);
603 EmitStmt(FD->getBody());
606 /// Tries to mark the given function nounwind based on the
607 /// non-existence of any throwing calls within it. We believe this is
608 /// lightweight enough to do at -O0.
609 static void TryMarkNoThrow(llvm::Function *F) {
610 // LLVM treats 'nounwind' on a function as part of the type, so we
611 // can't do this on functions that can be overwritten.
612 if (F->mayBeOverridden()) return;
614 for (llvm::Function::iterator FI = F->begin(), FE = F->end(); FI != FE; ++FI)
615 for (llvm::BasicBlock::iterator
616 BI = FI->begin(), BE = FI->end(); BI != BE; ++BI)
617 if (llvm::CallInst *Call = dyn_cast<llvm::CallInst>(&*BI)) {
618 if (!Call->doesNotThrow())
620 } else if (isa<llvm::ResumeInst>(&*BI)) {
623 F->setDoesNotThrow();
626 void CodeGenFunction::GenerateCode(GlobalDecl GD, llvm::Function *Fn,
627 const CGFunctionInfo &FnInfo) {
628 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
630 // Check if we should generate debug info for this function.
631 if (!FD->hasAttr<NoDebugAttr>())
632 maybeInitializeDebugInfo();
634 FunctionArgList Args;
635 QualType ResTy = FD->getResultType();
638 if (isa<CXXMethodDecl>(FD) && cast<CXXMethodDecl>(FD)->isInstance())
639 CGM.getCXXABI().BuildInstanceFunctionParams(*this, ResTy, Args);
641 for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i)
642 Args.push_back(FD->getParamDecl(i));
644 SourceRange BodyRange;
645 if (Stmt *Body = FD->getBody()) BodyRange = Body->getSourceRange();
647 // CalleeWithThisReturn keeps track of the last callee inside this function
648 // that returns 'this'. Before starting the function, we set it to null.
649 CalleeWithThisReturn = 0;
651 // Emit the standard function prologue.
652 StartFunction(GD, ResTy, Fn, FnInfo, Args, BodyRange.getBegin());
654 // Generate the body of the function.
655 if (isa<CXXDestructorDecl>(FD))
656 EmitDestructorBody(Args);
657 else if (isa<CXXConstructorDecl>(FD))
658 EmitConstructorBody(Args);
659 else if (getLangOpts().CUDA &&
660 !CGM.getCodeGenOpts().CUDAIsDevice &&
661 FD->hasAttr<CUDAGlobalAttr>())
662 CGM.getCUDARuntime().EmitDeviceStubBody(*this, Args);
663 else if (isa<CXXConversionDecl>(FD) &&
664 cast<CXXConversionDecl>(FD)->isLambdaToBlockPointerConversion()) {
665 // The lambda conversion to block pointer is special; the semantics can't be
666 // expressed in the AST, so IRGen needs to special-case it.
667 EmitLambdaToBlockPointerBody(Args);
668 } else if (isa<CXXMethodDecl>(FD) &&
669 cast<CXXMethodDecl>(FD)->isLambdaStaticInvoker()) {
670 // The lambda "__invoke" function is special, because it forwards or
671 // clones the body of the function call operator (but is actually static).
672 EmitLambdaStaticInvokeFunction(cast<CXXMethodDecl>(FD));
673 } else if (FD->isDefaulted() && isa<CXXMethodDecl>(FD) &&
674 cast<CXXMethodDecl>(FD)->isCopyAssignmentOperator()) {
675 // Implicit copy-assignment gets the same special treatment as implicit
676 // copy-constructors.
677 emitImplicitAssignmentOperatorBody(Args);
680 EmitFunctionBody(Args);
682 // C++11 [stmt.return]p2:
683 // Flowing off the end of a function [...] results in undefined behavior in
684 // a value-returning function.
686 // If the '}' that terminates a function is reached, and the value of the
687 // function call is used by the caller, the behavior is undefined.
688 if (getLangOpts().CPlusPlus && !FD->hasImplicitReturnZero() &&
689 !FD->getResultType()->isVoidType() && Builder.GetInsertBlock()) {
691 EmitCheck(Builder.getFalse(), "missing_return",
692 EmitCheckSourceLocation(FD->getLocation()),
693 ArrayRef<llvm::Value *>(), CRK_Unrecoverable);
694 else if (CGM.getCodeGenOpts().OptimizationLevel == 0)
695 Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::trap));
696 Builder.CreateUnreachable();
697 Builder.ClearInsertionPoint();
700 // Emit the standard function epilogue.
701 FinishFunction(BodyRange.getEnd());
702 // CalleeWithThisReturn keeps track of the last callee inside this function
703 // that returns 'this'. After finishing the function, we set it to null.
704 CalleeWithThisReturn = 0;
706 // If we haven't marked the function nothrow through other means, do
707 // a quick pass now to see if we can.
708 if (!CurFn->doesNotThrow())
709 TryMarkNoThrow(CurFn);
712 /// ContainsLabel - Return true if the statement contains a label in it. If
713 /// this statement is not executed normally, it not containing a label means
714 /// that we can just remove the code.
715 bool CodeGenFunction::ContainsLabel(const Stmt *S, bool IgnoreCaseStmts) {
716 // Null statement, not a label!
717 if (S == 0) return false;
719 // If this is a label, we have to emit the code, consider something like:
720 // if (0) { ... foo: bar(); } goto foo;
722 // TODO: If anyone cared, we could track __label__'s, since we know that you
723 // can't jump to one from outside their declared region.
724 if (isa<LabelStmt>(S))
727 // If this is a case/default statement, and we haven't seen a switch, we have
729 if (isa<SwitchCase>(S) && !IgnoreCaseStmts)
732 // If this is a switch statement, we want to ignore cases below it.
733 if (isa<SwitchStmt>(S))
734 IgnoreCaseStmts = true;
736 // Scan subexpressions for verboten labels.
737 for (Stmt::const_child_range I = S->children(); I; ++I)
738 if (ContainsLabel(*I, IgnoreCaseStmts))
744 /// containsBreak - Return true if the statement contains a break out of it.
745 /// If the statement (recursively) contains a switch or loop with a break
746 /// inside of it, this is fine.
747 bool CodeGenFunction::containsBreak(const Stmt *S) {
748 // Null statement, not a label!
749 if (S == 0) return false;
751 // If this is a switch or loop that defines its own break scope, then we can
752 // include it and anything inside of it.
753 if (isa<SwitchStmt>(S) || isa<WhileStmt>(S) || isa<DoStmt>(S) ||
757 if (isa<BreakStmt>(S))
760 // Scan subexpressions for verboten breaks.
761 for (Stmt::const_child_range I = S->children(); I; ++I)
762 if (containsBreak(*I))
769 /// ConstantFoldsToSimpleInteger - If the specified expression does not fold
770 /// to a constant, or if it does but contains a label, return false. If it
771 /// constant folds return true and set the boolean result in Result.
772 bool CodeGenFunction::ConstantFoldsToSimpleInteger(const Expr *Cond,
774 llvm::APSInt ResultInt;
775 if (!ConstantFoldsToSimpleInteger(Cond, ResultInt))
778 ResultBool = ResultInt.getBoolValue();
782 /// ConstantFoldsToSimpleInteger - If the specified expression does not fold
783 /// to a constant, or if it does but contains a label, return false. If it
784 /// constant folds return true and set the folded value.
785 bool CodeGenFunction::
786 ConstantFoldsToSimpleInteger(const Expr *Cond, llvm::APSInt &ResultInt) {
787 // FIXME: Rename and handle conversion of other evaluatable things
790 if (!Cond->EvaluateAsInt(Int, getContext()))
791 return false; // Not foldable, not integer or not fully evaluatable.
793 if (CodeGenFunction::ContainsLabel(Cond))
794 return false; // Contains a label.
802 /// EmitBranchOnBoolExpr - Emit a branch on a boolean condition (e.g. for an if
803 /// statement) to the specified blocks. Based on the condition, this might try
804 /// to simplify the codegen of the conditional based on the branch.
806 void CodeGenFunction::EmitBranchOnBoolExpr(const Expr *Cond,
807 llvm::BasicBlock *TrueBlock,
808 llvm::BasicBlock *FalseBlock) {
809 Cond = Cond->IgnoreParens();
811 if (const BinaryOperator *CondBOp = dyn_cast<BinaryOperator>(Cond)) {
812 // Handle X && Y in a condition.
813 if (CondBOp->getOpcode() == BO_LAnd) {
814 // If we have "1 && X", simplify the code. "0 && X" would have constant
815 // folded if the case was simple enough.
816 bool ConstantBool = false;
817 if (ConstantFoldsToSimpleInteger(CondBOp->getLHS(), ConstantBool) &&
819 // br(1 && X) -> br(X).
820 return EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock);
823 // If we have "X && 1", simplify the code to use an uncond branch.
824 // "X && 0" would have been constant folded to 0.
825 if (ConstantFoldsToSimpleInteger(CondBOp->getRHS(), ConstantBool) &&
827 // br(X && 1) -> br(X).
828 return EmitBranchOnBoolExpr(CondBOp->getLHS(), TrueBlock, FalseBlock);
831 // Emit the LHS as a conditional. If the LHS conditional is false, we
832 // want to jump to the FalseBlock.
833 llvm::BasicBlock *LHSTrue = createBasicBlock("land.lhs.true");
835 ConditionalEvaluation eval(*this);
836 EmitBranchOnBoolExpr(CondBOp->getLHS(), LHSTrue, FalseBlock);
839 // Any temporaries created here are conditional.
841 EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock);
847 if (CondBOp->getOpcode() == BO_LOr) {
848 // If we have "0 || X", simplify the code. "1 || X" would have constant
849 // folded if the case was simple enough.
850 bool ConstantBool = false;
851 if (ConstantFoldsToSimpleInteger(CondBOp->getLHS(), ConstantBool) &&
853 // br(0 || X) -> br(X).
854 return EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock);
857 // If we have "X || 0", simplify the code to use an uncond branch.
858 // "X || 1" would have been constant folded to 1.
859 if (ConstantFoldsToSimpleInteger(CondBOp->getRHS(), ConstantBool) &&
861 // br(X || 0) -> br(X).
862 return EmitBranchOnBoolExpr(CondBOp->getLHS(), TrueBlock, FalseBlock);
865 // Emit the LHS as a conditional. If the LHS conditional is true, we
866 // want to jump to the TrueBlock.
867 llvm::BasicBlock *LHSFalse = createBasicBlock("lor.lhs.false");
869 ConditionalEvaluation eval(*this);
870 EmitBranchOnBoolExpr(CondBOp->getLHS(), TrueBlock, LHSFalse);
873 // Any temporaries created here are conditional.
875 EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock);
882 if (const UnaryOperator *CondUOp = dyn_cast<UnaryOperator>(Cond)) {
883 // br(!x, t, f) -> br(x, f, t)
884 if (CondUOp->getOpcode() == UO_LNot)
885 return EmitBranchOnBoolExpr(CondUOp->getSubExpr(), FalseBlock, TrueBlock);
888 if (const ConditionalOperator *CondOp = dyn_cast<ConditionalOperator>(Cond)) {
889 // br(c ? x : y, t, f) -> br(c, br(x, t, f), br(y, t, f))
890 llvm::BasicBlock *LHSBlock = createBasicBlock("cond.true");
891 llvm::BasicBlock *RHSBlock = createBasicBlock("cond.false");
893 ConditionalEvaluation cond(*this);
894 EmitBranchOnBoolExpr(CondOp->getCond(), LHSBlock, RHSBlock);
898 EmitBranchOnBoolExpr(CondOp->getLHS(), TrueBlock, FalseBlock);
903 EmitBranchOnBoolExpr(CondOp->getRHS(), TrueBlock, FalseBlock);
909 // Emit the code with the fully general case.
910 llvm::Value *CondV = EvaluateExprAsBool(Cond);
911 Builder.CreateCondBr(CondV, TrueBlock, FalseBlock);
914 /// ErrorUnsupported - Print out an error that codegen doesn't support the
915 /// specified stmt yet.
916 void CodeGenFunction::ErrorUnsupported(const Stmt *S, const char *Type,
918 CGM.ErrorUnsupported(S, Type, OmitOnError);
921 /// emitNonZeroVLAInit - Emit the "zero" initialization of a
922 /// variable-length array whose elements have a non-zero bit-pattern.
924 /// \param baseType the inner-most element type of the array
925 /// \param src - a char* pointing to the bit-pattern for a single
926 /// base element of the array
927 /// \param sizeInChars - the total size of the VLA, in chars
928 static void emitNonZeroVLAInit(CodeGenFunction &CGF, QualType baseType,
929 llvm::Value *dest, llvm::Value *src,
930 llvm::Value *sizeInChars) {
931 std::pair<CharUnits,CharUnits> baseSizeAndAlign
932 = CGF.getContext().getTypeInfoInChars(baseType);
934 CGBuilderTy &Builder = CGF.Builder;
936 llvm::Value *baseSizeInChars
937 = llvm::ConstantInt::get(CGF.IntPtrTy, baseSizeAndAlign.first.getQuantity());
939 llvm::Type *i8p = Builder.getInt8PtrTy();
941 llvm::Value *begin = Builder.CreateBitCast(dest, i8p, "vla.begin");
942 llvm::Value *end = Builder.CreateInBoundsGEP(dest, sizeInChars, "vla.end");
944 llvm::BasicBlock *originBB = CGF.Builder.GetInsertBlock();
945 llvm::BasicBlock *loopBB = CGF.createBasicBlock("vla-init.loop");
946 llvm::BasicBlock *contBB = CGF.createBasicBlock("vla-init.cont");
948 // Make a loop over the VLA. C99 guarantees that the VLA element
949 // count must be nonzero.
950 CGF.EmitBlock(loopBB);
952 llvm::PHINode *cur = Builder.CreatePHI(i8p, 2, "vla.cur");
953 cur->addIncoming(begin, originBB);
955 // memcpy the individual element bit-pattern.
956 Builder.CreateMemCpy(cur, src, baseSizeInChars,
957 baseSizeAndAlign.second.getQuantity(),
960 // Go to the next element.
961 llvm::Value *next = Builder.CreateConstInBoundsGEP1_32(cur, 1, "vla.next");
963 // Leave if that's the end of the VLA.
964 llvm::Value *done = Builder.CreateICmpEQ(next, end, "vla-init.isdone");
965 Builder.CreateCondBr(done, contBB, loopBB);
966 cur->addIncoming(next, loopBB);
968 CGF.EmitBlock(contBB);
972 CodeGenFunction::EmitNullInitialization(llvm::Value *DestPtr, QualType Ty) {
973 // Ignore empty classes in C++.
974 if (getLangOpts().CPlusPlus) {
975 if (const RecordType *RT = Ty->getAs<RecordType>()) {
976 if (cast<CXXRecordDecl>(RT->getDecl())->isEmpty())
981 // Cast the dest ptr to the appropriate i8 pointer type.
983 cast<llvm::PointerType>(DestPtr->getType())->getAddressSpace();
984 llvm::Type *BP = Builder.getInt8PtrTy(DestAS);
985 if (DestPtr->getType() != BP)
986 DestPtr = Builder.CreateBitCast(DestPtr, BP);
988 // Get size and alignment info for this aggregate.
989 std::pair<CharUnits, CharUnits> TypeInfo =
990 getContext().getTypeInfoInChars(Ty);
991 CharUnits Size = TypeInfo.first;
992 CharUnits Align = TypeInfo.second;
994 llvm::Value *SizeVal;
995 const VariableArrayType *vla;
997 // Don't bother emitting a zero-byte memset.
999 // But note that getTypeInfo returns 0 for a VLA.
1000 if (const VariableArrayType *vlaType =
1001 dyn_cast_or_null<VariableArrayType>(
1002 getContext().getAsArrayType(Ty))) {
1004 llvm::Value *numElts;
1005 llvm::tie(numElts, eltType) = getVLASize(vlaType);
1008 CharUnits eltSize = getContext().getTypeSizeInChars(eltType);
1009 if (!eltSize.isOne())
1010 SizeVal = Builder.CreateNUWMul(SizeVal, CGM.getSize(eltSize));
1016 SizeVal = CGM.getSize(Size);
1020 // If the type contains a pointer to data member we can't memset it to zero.
1021 // Instead, create a null constant and copy it to the destination.
1022 // TODO: there are other patterns besides zero that we can usefully memset,
1023 // like -1, which happens to be the pattern used by member-pointers.
1024 if (!CGM.getTypes().isZeroInitializable(Ty)) {
1025 // For a VLA, emit a single element, then splat that over the VLA.
1026 if (vla) Ty = getContext().getBaseElementType(vla);
1028 llvm::Constant *NullConstant = CGM.EmitNullConstant(Ty);
1030 llvm::GlobalVariable *NullVariable =
1031 new llvm::GlobalVariable(CGM.getModule(), NullConstant->getType(),
1032 /*isConstant=*/true,
1033 llvm::GlobalVariable::PrivateLinkage,
1034 NullConstant, Twine());
1035 llvm::Value *SrcPtr =
1036 Builder.CreateBitCast(NullVariable, Builder.getInt8PtrTy());
1038 if (vla) return emitNonZeroVLAInit(*this, Ty, DestPtr, SrcPtr, SizeVal);
1040 // Get and call the appropriate llvm.memcpy overload.
1041 Builder.CreateMemCpy(DestPtr, SrcPtr, SizeVal, Align.getQuantity(), false);
1045 // Otherwise, just memset the whole thing to zero. This is legal
1046 // because in LLVM, all default initializers (other than the ones we just
1047 // handled above) are guaranteed to have a bit pattern of all zeros.
1048 Builder.CreateMemSet(DestPtr, Builder.getInt8(0), SizeVal,
1049 Align.getQuantity(), false);
1052 llvm::BlockAddress *CodeGenFunction::GetAddrOfLabel(const LabelDecl *L) {
1053 // Make sure that there is a block for the indirect goto.
1054 if (IndirectBranch == 0)
1055 GetIndirectGotoBlock();
1057 llvm::BasicBlock *BB = getJumpDestForLabel(L).getBlock();
1059 // Make sure the indirect branch includes all of the address-taken blocks.
1060 IndirectBranch->addDestination(BB);
1061 return llvm::BlockAddress::get(CurFn, BB);
1064 llvm::BasicBlock *CodeGenFunction::GetIndirectGotoBlock() {
1065 // If we already made the indirect branch for indirect goto, return its block.
1066 if (IndirectBranch) return IndirectBranch->getParent();
1068 CGBuilderTy TmpBuilder(createBasicBlock("indirectgoto"));
1070 // Create the PHI node that indirect gotos will add entries to.
1071 llvm::Value *DestVal = TmpBuilder.CreatePHI(Int8PtrTy, 0,
1072 "indirect.goto.dest");
1074 // Create the indirect branch instruction.
1075 IndirectBranch = TmpBuilder.CreateIndirectBr(DestVal);
1076 return IndirectBranch->getParent();
1079 /// Computes the length of an array in elements, as well as the base
1080 /// element type and a properly-typed first element pointer.
1081 llvm::Value *CodeGenFunction::emitArrayLength(const ArrayType *origArrayType,
1083 llvm::Value *&addr) {
1084 const ArrayType *arrayType = origArrayType;
1086 // If it's a VLA, we have to load the stored size. Note that
1087 // this is the size of the VLA in bytes, not its size in elements.
1088 llvm::Value *numVLAElements = 0;
1089 if (isa<VariableArrayType>(arrayType)) {
1090 numVLAElements = getVLASize(cast<VariableArrayType>(arrayType)).first;
1092 // Walk into all VLAs. This doesn't require changes to addr,
1093 // which has type T* where T is the first non-VLA element type.
1095 QualType elementType = arrayType->getElementType();
1096 arrayType = getContext().getAsArrayType(elementType);
1098 // If we only have VLA components, 'addr' requires no adjustment.
1100 baseType = elementType;
1101 return numVLAElements;
1103 } while (isa<VariableArrayType>(arrayType));
1105 // We get out here only if we find a constant array type
1109 // We have some number of constant-length arrays, so addr should
1110 // have LLVM type [M x [N x [...]]]*. Build a GEP that walks
1111 // down to the first element of addr.
1112 SmallVector<llvm::Value*, 8> gepIndices;
1114 // GEP down to the array type.
1115 llvm::ConstantInt *zero = Builder.getInt32(0);
1116 gepIndices.push_back(zero);
1118 uint64_t countFromCLAs = 1;
1121 llvm::ArrayType *llvmArrayType =
1122 dyn_cast<llvm::ArrayType>(
1123 cast<llvm::PointerType>(addr->getType())->getElementType());
1124 while (llvmArrayType) {
1125 assert(isa<ConstantArrayType>(arrayType));
1126 assert(cast<ConstantArrayType>(arrayType)->getSize().getZExtValue()
1127 == llvmArrayType->getNumElements());
1129 gepIndices.push_back(zero);
1130 countFromCLAs *= llvmArrayType->getNumElements();
1131 eltType = arrayType->getElementType();
1134 dyn_cast<llvm::ArrayType>(llvmArrayType->getElementType());
1135 arrayType = getContext().getAsArrayType(arrayType->getElementType());
1136 assert((!llvmArrayType || arrayType) &&
1137 "LLVM and Clang types are out-of-synch");
1141 // From this point onwards, the Clang array type has been emitted
1142 // as some other type (probably a packed struct). Compute the array
1143 // size, and just emit the 'begin' expression as a bitcast.
1146 cast<ConstantArrayType>(arrayType)->getSize().getZExtValue();
1147 eltType = arrayType->getElementType();
1148 arrayType = getContext().getAsArrayType(eltType);
1151 unsigned AddressSpace = addr->getType()->getPointerAddressSpace();
1152 llvm::Type *BaseType = ConvertType(eltType)->getPointerTo(AddressSpace);
1153 addr = Builder.CreateBitCast(addr, BaseType, "array.begin");
1155 // Create the actual GEP.
1156 addr = Builder.CreateInBoundsGEP(addr, gepIndices, "array.begin");
1161 llvm::Value *numElements
1162 = llvm::ConstantInt::get(SizeTy, countFromCLAs);
1164 // If we had any VLA dimensions, factor them in.
1166 numElements = Builder.CreateNUWMul(numVLAElements, numElements);
1171 std::pair<llvm::Value*, QualType>
1172 CodeGenFunction::getVLASize(QualType type) {
1173 const VariableArrayType *vla = getContext().getAsVariableArrayType(type);
1174 assert(vla && "type was not a variable array type!");
1175 return getVLASize(vla);
1178 std::pair<llvm::Value*, QualType>
1179 CodeGenFunction::getVLASize(const VariableArrayType *type) {
1180 // The number of elements so far; always size_t.
1181 llvm::Value *numElements = 0;
1183 QualType elementType;
1185 elementType = type->getElementType();
1186 llvm::Value *vlaSize = VLASizeMap[type->getSizeExpr()];
1187 assert(vlaSize && "no size for VLA!");
1188 assert(vlaSize->getType() == SizeTy);
1191 numElements = vlaSize;
1193 // It's undefined behavior if this wraps around, so mark it that way.
1194 // FIXME: Teach -fcatch-undefined-behavior to trap this.
1195 numElements = Builder.CreateNUWMul(numElements, vlaSize);
1197 } while ((type = getContext().getAsVariableArrayType(elementType)));
1199 return std::pair<llvm::Value*,QualType>(numElements, elementType);
1202 void CodeGenFunction::EmitVariablyModifiedType(QualType type) {
1203 assert(type->isVariablyModifiedType() &&
1204 "Must pass variably modified type to EmitVLASizes!");
1206 EnsureInsertPoint();
1208 // We're going to walk down into the type and look for VLA
1211 assert(type->isVariablyModifiedType());
1213 const Type *ty = type.getTypePtr();
1214 switch (ty->getTypeClass()) {
1216 #define TYPE(Class, Base)
1217 #define ABSTRACT_TYPE(Class, Base)
1218 #define NON_CANONICAL_TYPE(Class, Base)
1219 #define DEPENDENT_TYPE(Class, Base) case Type::Class:
1220 #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base)
1221 #include "clang/AST/TypeNodes.def"
1222 llvm_unreachable("unexpected dependent type!");
1224 // These types are never variably-modified.
1228 case Type::ExtVector:
1231 case Type::Elaborated:
1232 case Type::TemplateSpecialization:
1233 case Type::ObjCObject:
1234 case Type::ObjCInterface:
1235 case Type::ObjCObjectPointer:
1236 llvm_unreachable("type class is never variably-modified!");
1239 type = cast<PointerType>(ty)->getPointeeType();
1242 case Type::BlockPointer:
1243 type = cast<BlockPointerType>(ty)->getPointeeType();
1246 case Type::LValueReference:
1247 case Type::RValueReference:
1248 type = cast<ReferenceType>(ty)->getPointeeType();
1251 case Type::MemberPointer:
1252 type = cast<MemberPointerType>(ty)->getPointeeType();
1255 case Type::ConstantArray:
1256 case Type::IncompleteArray:
1257 // Losing element qualification here is fine.
1258 type = cast<ArrayType>(ty)->getElementType();
1261 case Type::VariableArray: {
1262 // Losing element qualification here is fine.
1263 const VariableArrayType *vat = cast<VariableArrayType>(ty);
1265 // Unknown size indication requires no size computation.
1266 // Otherwise, evaluate and record it.
1267 if (const Expr *size = vat->getSizeExpr()) {
1268 // It's possible that we might have emitted this already,
1269 // e.g. with a typedef and a pointer to it.
1270 llvm::Value *&entry = VLASizeMap[size];
1272 llvm::Value *Size = EmitScalarExpr(size);
1275 // If the size is an expression that is not an integer constant
1276 // expression [...] each time it is evaluated it shall have a value
1277 // greater than zero.
1278 if (SanOpts->VLABound &&
1279 size->getType()->isSignedIntegerType()) {
1280 llvm::Value *Zero = llvm::Constant::getNullValue(Size->getType());
1281 llvm::Constant *StaticArgs[] = {
1282 EmitCheckSourceLocation(size->getLocStart()),
1283 EmitCheckTypeDescriptor(size->getType())
1285 EmitCheck(Builder.CreateICmpSGT(Size, Zero),
1286 "vla_bound_not_positive", StaticArgs, Size,
1290 // Always zexting here would be wrong if it weren't
1291 // undefined behavior to have a negative bound.
1292 entry = Builder.CreateIntCast(Size, SizeTy, /*signed*/ false);
1295 type = vat->getElementType();
1299 case Type::FunctionProto:
1300 case Type::FunctionNoProto:
1301 type = cast<FunctionType>(ty)->getResultType();
1306 case Type::UnaryTransform:
1307 case Type::Attributed:
1308 case Type::SubstTemplateTypeParm:
1309 // Keep walking after single level desugaring.
1310 type = type.getSingleStepDesugaredType(getContext());
1314 case Type::Decltype:
1316 // Stop walking: nothing to do.
1319 case Type::TypeOfExpr:
1320 // Stop walking: emit typeof expression.
1321 EmitIgnoredExpr(cast<TypeOfExprType>(ty)->getUnderlyingExpr());
1325 type = cast<AtomicType>(ty)->getValueType();
1328 } while (type->isVariablyModifiedType());
1331 llvm::Value* CodeGenFunction::EmitVAListRef(const Expr* E) {
1332 if (getContext().getBuiltinVaListType()->isArrayType())
1333 return EmitScalarExpr(E);
1334 return EmitLValue(E).getAddress();
1337 void CodeGenFunction::EmitDeclRefExprDbgValue(const DeclRefExpr *E,
1338 llvm::Constant *Init) {
1339 assert (Init && "Invalid DeclRefExpr initializer!");
1340 if (CGDebugInfo *Dbg = getDebugInfo())
1341 if (CGM.getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo)
1342 Dbg->EmitGlobalVariable(E->getDecl(), Init);
1345 CodeGenFunction::PeepholeProtection
1346 CodeGenFunction::protectFromPeepholes(RValue rvalue) {
1347 // At the moment, the only aggressive peephole we do in IR gen
1348 // is trunc(zext) folding, but if we add more, we can easily
1349 // extend this protection.
1351 if (!rvalue.isScalar()) return PeepholeProtection();
1352 llvm::Value *value = rvalue.getScalarVal();
1353 if (!isa<llvm::ZExtInst>(value)) return PeepholeProtection();
1355 // Just make an extra bitcast.
1356 assert(HaveInsertPoint());
1357 llvm::Instruction *inst = new llvm::BitCastInst(value, value->getType(), "",
1358 Builder.GetInsertBlock());
1360 PeepholeProtection protection;
1361 protection.Inst = inst;
1365 void CodeGenFunction::unprotectFromPeepholes(PeepholeProtection protection) {
1366 if (!protection.Inst) return;
1368 // In theory, we could try to duplicate the peepholes now, but whatever.
1369 protection.Inst->eraseFromParent();
1372 llvm::Value *CodeGenFunction::EmitAnnotationCall(llvm::Value *AnnotationFn,
1373 llvm::Value *AnnotatedVal,
1374 StringRef AnnotationStr,
1375 SourceLocation Location) {
1376 llvm::Value *Args[4] = {
1378 Builder.CreateBitCast(CGM.EmitAnnotationString(AnnotationStr), Int8PtrTy),
1379 Builder.CreateBitCast(CGM.EmitAnnotationUnit(Location), Int8PtrTy),
1380 CGM.EmitAnnotationLineNo(Location)
1382 return Builder.CreateCall(AnnotationFn, Args);
1385 void CodeGenFunction::EmitVarAnnotations(const VarDecl *D, llvm::Value *V) {
1386 assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute");
1387 // FIXME We create a new bitcast for every annotation because that's what
1388 // llvm-gcc was doing.
1389 for (specific_attr_iterator<AnnotateAttr>
1390 ai = D->specific_attr_begin<AnnotateAttr>(),
1391 ae = D->specific_attr_end<AnnotateAttr>(); ai != ae; ++ai)
1392 EmitAnnotationCall(CGM.getIntrinsic(llvm::Intrinsic::var_annotation),
1393 Builder.CreateBitCast(V, CGM.Int8PtrTy, V->getName()),
1394 (*ai)->getAnnotation(), D->getLocation());
1397 llvm::Value *CodeGenFunction::EmitFieldAnnotations(const FieldDecl *D,
1399 assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute");
1400 llvm::Type *VTy = V->getType();
1401 llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::ptr_annotation,
1404 for (specific_attr_iterator<AnnotateAttr>
1405 ai = D->specific_attr_begin<AnnotateAttr>(),
1406 ae = D->specific_attr_end<AnnotateAttr>(); ai != ae; ++ai) {
1407 // FIXME Always emit the cast inst so we can differentiate between
1408 // annotation on the first field of a struct and annotation on the struct
1410 if (VTy != CGM.Int8PtrTy)
1411 V = Builder.Insert(new llvm::BitCastInst(V, CGM.Int8PtrTy));
1412 V = EmitAnnotationCall(F, V, (*ai)->getAnnotation(), D->getLocation());
1413 V = Builder.CreateBitCast(V, VTy);