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Reid Spencer5f016e22007-07-11 17:01:13 +00001//===--- CodeGenFunction.cpp - Emit LLVM Code from ASTs for a Function ----===//
2//
3// The LLVM Compiler Infrastructure
4//
Chris Lattner0bc735f2007-12-29 19:59:25 +00005// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
Reid Spencer5f016e22007-07-11 17:01:13 +00007//
8//===----------------------------------------------------------------------===//
9//
10// This coordinates the per-function state used while generating code.
11//
12//===----------------------------------------------------------------------===//
13
14#include "CodeGenFunction.h"
Peter Collingbournea4ae2292011-10-06 18:51:56 +000015#include "CGCUDARuntime.h"
John McCall4c40d982010-08-31 07:33:07 +000016#include "CGCXXABI.h"
Eli Friedman3f2af102008-05-22 01:40:10 +000017#include "CGDebugInfo.h"
Chandler Carruth55fc8732012-12-04 09:13:33 +000018#include "CodeGenModule.h"
Daniel Dunbarde7fb842008-08-11 05:00:27 +000019#include "clang/AST/ASTContext.h"
Daniel Dunbarc4a1dea2008-08-11 05:35:13 +000020#include "clang/AST/Decl.h"
Anders Carlsson2b77ba82009-04-04 20:47:02 +000021#include "clang/AST/DeclCXX.h"
Mike Stump6a1e0eb2009-12-04 23:26:17 +000022#include "clang/AST/StmtCXX.h"
Chandler Carruth55fc8732012-12-04 09:13:33 +000023#include "clang/Basic/TargetInfo.h"
Chris Lattner7255a2d2010-06-22 00:03:40 +000024#include "clang/Frontend/CodeGenOptions.h"
Chandler Carruth3b844ba2013-01-02 11:45:17 +000025#include "llvm/IR/DataLayout.h"
26#include "llvm/IR/Intrinsics.h"
27#include "llvm/IR/MDBuilder.h"
28#include "llvm/IR/Operator.h"
Reid Spencer5f016e22007-07-11 17:01:13 +000029using namespace clang;
30using namespace CodeGen;
31
Fariborz Jahanian4904bf42012-06-26 16:06:38 +000032CodeGenFunction::CodeGenFunction(CodeGenModule &cgm, bool suppressNewContext)
John McCall5936e332011-02-15 09:22:45 +000033 : CodeGenTypeCache(cgm), CGM(cgm),
Eli Friedmancec5ebd2012-02-11 02:57:39 +000034 Target(CGM.getContext().getTargetInfo()),
35 Builder(cgm.getModule().getContext()),
Will Dietz4f45bc02013-01-18 11:30:38 +000036 SanitizePerformTypeCheck(CGM.getSanOpts().Null |
37 CGM.getSanOpts().Alignment |
38 CGM.getSanOpts().ObjectSize |
39 CGM.getSanOpts().Vptr),
40 SanOpts(&CGM.getSanOpts()),
John McCallf85e1932011-06-15 23:02:42 +000041 AutoreleaseResult(false), BlockInfo(0), BlockPointer(0),
Eli Friedman23f02672012-03-01 04:01:32 +000042 LambdaThisCaptureField(0), NormalCleanupDest(0), NextCleanupDestIndex(1),
Eli Friedmancec5ebd2012-02-11 02:57:39 +000043 FirstBlockInfo(0), EHResumeBlock(0), ExceptionSlot(0), EHSelectorSlot(0),
John McCall93c332a2011-05-28 21:13:02 +000044 DebugInfo(0), DisableDebugInfo(false), DidCallStackSave(false),
45 IndirectBranch(0), SwitchInsn(0), CaseRangeBlock(0), UnreachableBlock(0),
Timur Iskhodzhanov59660c22013-02-13 08:37:51 +000046 CXXABIThisDecl(0), CXXABIThisValue(0), CXXThisValue(0),
47 CXXStructorImplicitParamDecl(0), CXXStructorImplicitParamValue(0),
48 OutermostConditional(0), TerminateLandingPad(0),
Eli Friedmancec5ebd2012-02-11 02:57:39 +000049 TerminateHandler(0), TrapBB(0) {
Fariborz Jahanian4904bf42012-06-26 16:06:38 +000050 if (!suppressNewContext)
51 CGM.getCXXABI().getMangleContext().startNewFunction();
Michael Ilsemancdeb7d52012-12-04 00:36:06 +000052
53 llvm::FastMathFlags FMF;
54 if (CGM.getLangOpts().FastMath)
Benjamin Kramer29573b02012-12-09 21:58:24 +000055 FMF.setUnsafeAlgebra();
Michael Ilsemancdeb7d52012-12-04 00:36:06 +000056 if (CGM.getLangOpts().FiniteMathOnly) {
Benjamin Kramer29573b02012-12-09 21:58:24 +000057 FMF.setNoNaNs();
58 FMF.setNoInfs();
Michael Ilsemancdeb7d52012-12-04 00:36:06 +000059 }
60 Builder.SetFastMathFlags(FMF);
Chris Lattner41110242008-06-17 18:05:57 +000061}
Reid Spencer5f016e22007-07-11 17:01:13 +000062
John McCall1a343eb2011-11-10 08:15:53 +000063CodeGenFunction::~CodeGenFunction() {
64 // If there are any unclaimed block infos, go ahead and destroy them
65 // now. This can happen if IR-gen gets clever and skips evaluating
66 // something.
67 if (FirstBlockInfo)
68 destroyBlockInfos(FirstBlockInfo);
69}
70
Reid Spencer5f016e22007-07-11 17:01:13 +000071
Chris Lattner9cbe4f02011-07-09 17:41:47 +000072llvm::Type *CodeGenFunction::ConvertTypeForMem(QualType T) {
Daniel Dunbar8b1a3432009-02-03 23:03:55 +000073 return CGM.getTypes().ConvertTypeForMem(T);
74}
75
Chris Lattner9cbe4f02011-07-09 17:41:47 +000076llvm::Type *CodeGenFunction::ConvertType(QualType T) {
Reid Spencer5f016e22007-07-11 17:01:13 +000077 return CGM.getTypes().ConvertType(T);
78}
79
John McCall9d232c82013-03-07 21:37:08 +000080TypeEvaluationKind CodeGenFunction::getEvaluationKind(QualType type) {
81 type = type.getCanonicalType();
82 while (true) {
83 switch (type->getTypeClass()) {
John McCallf2aac842011-05-15 02:34:36 +000084#define TYPE(name, parent)
85#define ABSTRACT_TYPE(name, parent)
86#define NON_CANONICAL_TYPE(name, parent) case Type::name:
87#define DEPENDENT_TYPE(name, parent) case Type::name:
88#define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(name, parent) case Type::name:
89#include "clang/AST/TypeNodes.def"
John McCall9d232c82013-03-07 21:37:08 +000090 llvm_unreachable("non-canonical or dependent type in IR-generation");
John McCallf2aac842011-05-15 02:34:36 +000091
John McCall9d232c82013-03-07 21:37:08 +000092 // Various scalar types.
93 case Type::Builtin:
94 case Type::Pointer:
95 case Type::BlockPointer:
96 case Type::LValueReference:
97 case Type::RValueReference:
98 case Type::MemberPointer:
99 case Type::Vector:
100 case Type::ExtVector:
101 case Type::FunctionProto:
102 case Type::FunctionNoProto:
103 case Type::Enum:
104 case Type::ObjCObjectPointer:
105 return TEK_Scalar;
John McCallf2aac842011-05-15 02:34:36 +0000106
John McCall9d232c82013-03-07 21:37:08 +0000107 // Complexes.
108 case Type::Complex:
109 return TEK_Complex;
Eli Friedmanb001de72011-10-06 23:00:33 +0000110
John McCall9d232c82013-03-07 21:37:08 +0000111 // Arrays, records, and Objective-C objects.
112 case Type::ConstantArray:
113 case Type::IncompleteArray:
114 case Type::VariableArray:
115 case Type::Record:
116 case Type::ObjCObject:
117 case Type::ObjCInterface:
118 return TEK_Aggregate;
119
120 // We operate on atomic values according to their underlying type.
121 case Type::Atomic:
122 type = cast<AtomicType>(type)->getValueType();
123 continue;
124 }
125 llvm_unreachable("unknown type kind!");
John McCallf2aac842011-05-15 02:34:36 +0000126 }
Reid Spencer5f016e22007-07-11 17:01:13 +0000127}
128
David Blaikie0a0f93c2013-02-01 19:09:49 +0000129void CodeGenFunction::EmitReturnBlock() {
Daniel Dunbar1c1d6072009-01-26 23:27:52 +0000130 // For cleanliness, we try to avoid emitting the return block for
131 // simple cases.
132 llvm::BasicBlock *CurBB = Builder.GetInsertBlock();
133
134 if (CurBB) {
135 assert(!CurBB->getTerminator() && "Unexpected terminated block.");
136
Daniel Dunbar96e18b02009-07-19 08:24:34 +0000137 // We have a valid insert point, reuse it if it is empty or there are no
138 // explicit jumps to the return block.
John McCallff8e1152010-07-23 21:56:41 +0000139 if (CurBB->empty() || ReturnBlock.getBlock()->use_empty()) {
140 ReturnBlock.getBlock()->replaceAllUsesWith(CurBB);
141 delete ReturnBlock.getBlock();
Daniel Dunbar96e18b02009-07-19 08:24:34 +0000142 } else
John McCallff8e1152010-07-23 21:56:41 +0000143 EmitBlock(ReturnBlock.getBlock());
David Blaikie0a0f93c2013-02-01 19:09:49 +0000144 return;
Daniel Dunbar1c1d6072009-01-26 23:27:52 +0000145 }
146
147 // Otherwise, if the return block is the target of a single direct
148 // branch then we can just put the code in that block instead. This
149 // cleans up functions which started with a unified return block.
John McCallff8e1152010-07-23 21:56:41 +0000150 if (ReturnBlock.getBlock()->hasOneUse()) {
Mike Stump1eb44332009-09-09 15:08:12 +0000151 llvm::BranchInst *BI =
John McCallff8e1152010-07-23 21:56:41 +0000152 dyn_cast<llvm::BranchInst>(*ReturnBlock.getBlock()->use_begin());
John McCallf1549f62010-07-06 01:34:17 +0000153 if (BI && BI->isUnconditional() &&
John McCallff8e1152010-07-23 21:56:41 +0000154 BI->getSuccessor(0) == ReturnBlock.getBlock()) {
David Blaikiec5139a92013-02-23 19:20:56 +0000155 // Reset insertion point, including debug location, and delete the
156 // branch. This is really subtle and only works because the next change
157 // in location will hit the caching in CGDebugInfo::EmitLocation and not
158 // override this.
Eric Christopheracae0112011-09-09 21:53:04 +0000159 Builder.SetCurrentDebugLocation(BI->getDebugLoc());
Daniel Dunbar1c1d6072009-01-26 23:27:52 +0000160 Builder.SetInsertPoint(BI->getParent());
161 BI->eraseFromParent();
John McCallff8e1152010-07-23 21:56:41 +0000162 delete ReturnBlock.getBlock();
David Blaikie0a0f93c2013-02-01 19:09:49 +0000163 return;
Daniel Dunbar1c1d6072009-01-26 23:27:52 +0000164 }
165 }
166
Mike Stumpf5408fe2009-05-16 07:57:57 +0000167 // FIXME: We are at an unreachable point, there is no reason to emit the block
168 // unless it has uses. However, we still need a place to put the debug
169 // region.end for now.
Daniel Dunbar1c1d6072009-01-26 23:27:52 +0000170
John McCallff8e1152010-07-23 21:56:41 +0000171 EmitBlock(ReturnBlock.getBlock());
John McCallf1549f62010-07-06 01:34:17 +0000172}
173
174static void EmitIfUsed(CodeGenFunction &CGF, llvm::BasicBlock *BB) {
175 if (!BB) return;
176 if (!BB->use_empty())
177 return CGF.CurFn->getBasicBlockList().push_back(BB);
178 delete BB;
Daniel Dunbar1c1d6072009-01-26 23:27:52 +0000179}
180
Daniel Dunbaraf05bb92008-08-26 08:29:31 +0000181void CodeGenFunction::FinishFunction(SourceLocation EndLoc) {
Chris Lattnerda138702007-07-16 21:28:45 +0000182 assert(BreakContinueStack.empty() &&
183 "mismatched push/pop in break/continue stack!");
Mike Stump1eb44332009-09-09 15:08:12 +0000184
David Blaikie0a0f93c2013-02-01 19:09:49 +0000185 if (CGDebugInfo *DI = getDebugInfo())
186 DI->EmitLocation(Builder, EndLoc);
187
John McCallf85e1932011-06-15 23:02:42 +0000188 // Pop any cleanups that might have been associated with the
189 // parameters. Do this in whatever block we're currently in; it's
190 // important to do this before we enter the return block or return
191 // edges will be *really* confused.
192 if (EHStack.stable_begin() != PrologueCleanupDepth)
193 PopCleanupBlocks(PrologueCleanupDepth);
194
Mike Stump1eb44332009-09-09 15:08:12 +0000195 // Emit function epilog (to return).
David Blaikie0a0f93c2013-02-01 19:09:49 +0000196 EmitReturnBlock();
Daniel Dunbarf5bd45c2008-11-11 20:59:54 +0000197
Daniel Dunbara18652f2011-02-10 17:32:22 +0000198 if (ShouldInstrumentFunction())
199 EmitFunctionInstrumentation("__cyg_profile_func_exit");
Chris Lattner7255a2d2010-06-22 00:03:40 +0000200
Daniel Dunbarf5bd45c2008-11-11 20:59:54 +0000201 // Emit debug descriptor for function end.
Anders Carlssone896d982009-02-13 08:11:52 +0000202 if (CGDebugInfo *DI = getDebugInfo()) {
Devang Patel5a6fbcf2010-07-22 22:29:16 +0000203 DI->EmitFunctionEnd(Builder);
Daniel Dunbarf5bd45c2008-11-11 20:59:54 +0000204 }
205
Chris Lattner35b21b82010-06-27 01:06:27 +0000206 EmitFunctionEpilog(*CurFnInfo);
Mike Stumpcce3d4f2009-12-07 23:38:24 +0000207 EmitEndEHSpec(CurCodeDecl);
Daniel Dunbar5ca20842008-09-09 21:00:17 +0000208
John McCallf1549f62010-07-06 01:34:17 +0000209 assert(EHStack.empty() &&
210 "did not remove all scopes from cleanup stack!");
211
Chris Lattnerd9becd12009-10-28 23:59:40 +0000212 // If someone did an indirect goto, emit the indirect goto block at the end of
213 // the function.
214 if (IndirectBranch) {
215 EmitBlock(IndirectBranch->getParent());
216 Builder.ClearInsertionPoint();
217 }
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000218
Chris Lattner5a2fa142007-12-02 06:32:24 +0000219 // Remove the AllocaInsertPt instruction, which is just a convenience for us.
Chris Lattner481769b2009-03-31 22:17:44 +0000220 llvm::Instruction *Ptr = AllocaInsertPt;
Chris Lattner5a2fa142007-12-02 06:32:24 +0000221 AllocaInsertPt = 0;
Chris Lattner481769b2009-03-31 22:17:44 +0000222 Ptr->eraseFromParent();
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000223
Chris Lattnerd9becd12009-10-28 23:59:40 +0000224 // If someone took the address of a label but never did an indirect goto, we
225 // made a zero entry PHI node, which is illegal, zap it now.
226 if (IndirectBranch) {
227 llvm::PHINode *PN = cast<llvm::PHINode>(IndirectBranch->getAddress());
228 if (PN->getNumIncomingValues() == 0) {
229 PN->replaceAllUsesWith(llvm::UndefValue::get(PN->getType()));
230 PN->eraseFromParent();
231 }
232 }
John McCallf1549f62010-07-06 01:34:17 +0000233
John McCall777d6e52011-08-11 02:22:43 +0000234 EmitIfUsed(*this, EHResumeBlock);
John McCallf1549f62010-07-06 01:34:17 +0000235 EmitIfUsed(*this, TerminateLandingPad);
236 EmitIfUsed(*this, TerminateHandler);
237 EmitIfUsed(*this, UnreachableBlock);
John McCall744016d2010-07-06 23:57:41 +0000238
239 if (CGM.getCodeGenOpts().EmitDeclMetadata)
240 EmitDeclMetadata();
Reid Spencer5f016e22007-07-11 17:01:13 +0000241}
242
Chris Lattner7255a2d2010-06-22 00:03:40 +0000243/// ShouldInstrumentFunction - Return true if the current function should be
244/// instrumented with __cyg_profile_func_* calls
245bool CodeGenFunction::ShouldInstrumentFunction() {
246 if (!CGM.getCodeGenOpts().InstrumentFunctions)
247 return false;
Ted Kremenek7aa488a2011-05-16 23:49:20 +0000248 if (!CurFuncDecl || CurFuncDecl->hasAttr<NoInstrumentFunctionAttr>())
Chris Lattner7255a2d2010-06-22 00:03:40 +0000249 return false;
250 return true;
251}
252
253/// EmitFunctionInstrumentation - Emit LLVM code to call the specified
254/// instrumentation function with the current function and the call site, if
255/// function instrumentation is enabled.
256void CodeGenFunction::EmitFunctionInstrumentation(const char *Fn) {
Chris Lattner8dab6572010-06-23 05:21:28 +0000257 // void __cyg_profile_func_{enter,exit} (void *this_fn, void *call_site);
Chris Lattner9cbe4f02011-07-09 17:41:47 +0000258 llvm::PointerType *PointerTy = Int8PtrTy;
259 llvm::Type *ProfileFuncArgs[] = { PointerTy, PointerTy };
Chris Lattner2acc6e32011-07-18 04:24:23 +0000260 llvm::FunctionType *FunctionTy =
Chris Lattner8b418682012-02-07 00:39:47 +0000261 llvm::FunctionType::get(VoidTy, ProfileFuncArgs, false);
Chris Lattner7255a2d2010-06-22 00:03:40 +0000262
263 llvm::Constant *F = CGM.CreateRuntimeFunction(FunctionTy, Fn);
264 llvm::CallInst *CallSite = Builder.CreateCall(
Benjamin Kramer8dd55a32011-07-14 17:45:50 +0000265 CGM.getIntrinsic(llvm::Intrinsic::returnaddress),
Chris Lattner77b89b82010-06-27 07:15:29 +0000266 llvm::ConstantInt::get(Int32Ty, 0),
Chris Lattner7255a2d2010-06-22 00:03:40 +0000267 "callsite");
268
John McCallbd7370a2013-02-28 19:01:20 +0000269 llvm::Value *args[] = {
270 llvm::ConstantExpr::getBitCast(CurFn, PointerTy),
271 CallSite
272 };
273
274 EmitNounwindRuntimeCall(F, args);
Chris Lattner7255a2d2010-06-22 00:03:40 +0000275}
276
Roman Divackybe4c8702011-02-10 16:52:03 +0000277void CodeGenFunction::EmitMCountInstrumentation() {
Chris Lattner8b418682012-02-07 00:39:47 +0000278 llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
Roman Divackybe4c8702011-02-10 16:52:03 +0000279
280 llvm::Constant *MCountFn = CGM.CreateRuntimeFunction(FTy,
281 Target.getMCountName());
John McCallbd7370a2013-02-28 19:01:20 +0000282 EmitNounwindRuntimeCall(MCountFn);
Roman Divackybe4c8702011-02-10 16:52:03 +0000283}
284
Tanya Lattner198871c2012-07-11 23:02:10 +0000285// OpenCL v1.2 s5.6.4.6 allows the compiler to store kernel argument
286// information in the program executable. The argument information stored
287// includes the argument name, its type, the address and access qualifiers used.
288// FIXME: Add type, address, and access qualifiers.
289static void GenOpenCLArgMetadata(const FunctionDecl *FD, llvm::Function *Fn,
290 CodeGenModule &CGM,llvm::LLVMContext &Context,
Dmitri Gribenkocfa88f82013-01-12 19:30:44 +0000291 SmallVector <llvm::Value*, 5> &kernelMDArgs) {
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000292
Tanya Lattner198871c2012-07-11 23:02:10 +0000293 // Create MDNodes that represents the kernel arg metadata.
294 // Each MDNode is a list in the form of "key", N number of values which is
295 // the same number of values as their are kernel arguments.
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000296
Tanya Lattner198871c2012-07-11 23:02:10 +0000297 // MDNode for the kernel argument names.
298 SmallVector<llvm::Value*, 8> argNames;
299 argNames.push_back(llvm::MDString::get(Context, "kernel_arg_name"));
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000300
Tanya Lattner198871c2012-07-11 23:02:10 +0000301 for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i) {
302 const ParmVarDecl *parm = FD->getParamDecl(i);
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000303
Tanya Lattner198871c2012-07-11 23:02:10 +0000304 // Get argument name.
305 argNames.push_back(llvm::MDString::get(Context, parm->getName()));
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000306
Tanya Lattner198871c2012-07-11 23:02:10 +0000307 }
308 // Add MDNode to the list of all metadata.
309 kernelMDArgs.push_back(llvm::MDNode::get(Context, argNames));
310}
311
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000312void CodeGenFunction::EmitOpenCLKernelMetadata(const FunctionDecl *FD,
Tanya Lattner0df579e2012-07-09 22:06:01 +0000313 llvm::Function *Fn)
314{
315 if (!FD->hasAttr<OpenCLKernelAttr>())
316 return;
317
318 llvm::LLVMContext &Context = getLLVMContext();
319
Dmitri Gribenkocfa88f82013-01-12 19:30:44 +0000320 SmallVector <llvm::Value*, 5> kernelMDArgs;
Tanya Lattner0df579e2012-07-09 22:06:01 +0000321 kernelMDArgs.push_back(Fn);
322
Tanya Lattner198871c2012-07-11 23:02:10 +0000323 if (CGM.getCodeGenOpts().EmitOpenCLArgMetadata)
324 GenOpenCLArgMetadata(FD, Fn, CGM, Context, kernelMDArgs);
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000325
Joey Gouly37453b92013-03-08 09:42:32 +0000326 if (FD->hasAttr<VecTypeHintAttr>()) {
327 VecTypeHintAttr *attr = FD->getAttr<VecTypeHintAttr>();
328 QualType hintQTy = attr->getTypeHint();
329 const ExtVectorType *hintEltQTy = hintQTy->getAs<ExtVectorType>();
330 bool isSignedInteger =
331 hintQTy->isSignedIntegerType() ||
332 (hintEltQTy && hintEltQTy->getElementType()->isSignedIntegerType());
333 llvm::Value *attrMDArgs[] = {
334 llvm::MDString::get(Context, "vec_type_hint"),
335 llvm::UndefValue::get(CGM.getTypes().ConvertType(attr->getTypeHint())),
336 llvm::ConstantInt::get(
337 llvm::IntegerType::get(Context, 32),
338 llvm::APInt(32, (uint64_t)(isSignedInteger ? 1 : 0)))
339 };
340 kernelMDArgs.push_back(llvm::MDNode::get(Context, attrMDArgs));
341 }
342
Tanya Lattner0df579e2012-07-09 22:06:01 +0000343 if (FD->hasAttr<WorkGroupSizeHintAttr>()) {
Tanya Lattner0df579e2012-07-09 22:06:01 +0000344 WorkGroupSizeHintAttr *attr = FD->getAttr<WorkGroupSizeHintAttr>();
Benjamin Kramer8fd8ee92012-11-15 16:40:35 +0000345 llvm::Value *attrMDArgs[] = {
346 llvm::MDString::get(Context, "work_group_size_hint"),
347 Builder.getInt32(attr->getXDim()),
348 Builder.getInt32(attr->getYDim()),
349 Builder.getInt32(attr->getZDim())
350 };
Tanya Lattner0df579e2012-07-09 22:06:01 +0000351 kernelMDArgs.push_back(llvm::MDNode::get(Context, attrMDArgs));
352 }
353
354 if (FD->hasAttr<ReqdWorkGroupSizeAttr>()) {
Tanya Lattner0df579e2012-07-09 22:06:01 +0000355 ReqdWorkGroupSizeAttr *attr = FD->getAttr<ReqdWorkGroupSizeAttr>();
Benjamin Kramer8fd8ee92012-11-15 16:40:35 +0000356 llvm::Value *attrMDArgs[] = {
357 llvm::MDString::get(Context, "reqd_work_group_size"),
358 Builder.getInt32(attr->getXDim()),
359 Builder.getInt32(attr->getYDim()),
360 Builder.getInt32(attr->getZDim())
361 };
Tanya Lattner0df579e2012-07-09 22:06:01 +0000362 kernelMDArgs.push_back(llvm::MDNode::get(Context, attrMDArgs));
363 }
364
365 llvm::MDNode *kernelMDNode = llvm::MDNode::get(Context, kernelMDArgs);
366 llvm::NamedMDNode *OpenCLKernelMetadata =
367 CGM.getModule().getOrInsertNamedMetadata("opencl.kernels");
368 OpenCLKernelMetadata->addOperand(kernelMDNode);
369}
370
Anders Carlsson0ff8baf2009-09-11 00:07:24 +0000371void CodeGenFunction::StartFunction(GlobalDecl GD, QualType RetTy,
Daniel Dunbar7c086512008-09-09 23:14:03 +0000372 llvm::Function *Fn,
John McCalld26bc762011-03-09 04:27:21 +0000373 const CGFunctionInfo &FnInfo,
Daniel Dunbar2284ac92008-10-18 18:22:23 +0000374 const FunctionArgList &Args,
Tilmann Scheller9c6082f2011-03-02 21:36:49 +0000375 SourceLocation StartLoc) {
Anders Carlsson0ff8baf2009-09-11 00:07:24 +0000376 const Decl *D = GD.getDecl();
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000377
Anders Carlsson4cc1a472009-02-09 20:20:56 +0000378 DidCallStackSave = false;
Chris Lattnerb5437d22009-04-23 05:30:27 +0000379 CurCodeDecl = CurFuncDecl = D;
Daniel Dunbar7c086512008-09-09 23:14:03 +0000380 FnRetTy = RetTy;
Daniel Dunbarbd012ff2008-07-29 23:18:29 +0000381 CurFn = Fn;
John McCalld26bc762011-03-09 04:27:21 +0000382 CurFnInfo = &FnInfo;
Chris Lattner41110242008-06-17 18:05:57 +0000383 assert(CurFn->isDeclaration() && "Function already has body?");
384
Will Dietz4f45bc02013-01-18 11:30:38 +0000385 if (CGM.getSanitizerBlacklist().isIn(*Fn)) {
386 SanOpts = &SanitizerOptions::Disabled;
387 SanitizePerformTypeCheck = false;
388 }
389
Jakob Stoklund Olesena3fe2842010-02-09 00:10:00 +0000390 // Pass inline keyword to optimizer if it appears explicitly on any
391 // declaration.
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000392 if (!CGM.getCodeGenOpts().NoInline)
Chad Rosier8fbe3852012-03-14 23:32:11 +0000393 if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D))
394 for (FunctionDecl::redecl_iterator RI = FD->redecls_begin(),
395 RE = FD->redecls_end(); RI != RE; ++RI)
396 if (RI->isInlineSpecified()) {
Bill Wendling72390b32012-12-20 19:27:06 +0000397 Fn->addFnAttr(llvm::Attribute::InlineHint);
Chad Rosier8fbe3852012-03-14 23:32:11 +0000398 break;
399 }
Jakob Stoklund Olesena3fe2842010-02-09 00:10:00 +0000400
Richard Smith7edf9e32012-11-01 22:30:59 +0000401 if (getLangOpts().OpenCL) {
Peter Collingbournef315fa82011-02-14 01:42:53 +0000402 // Add metadata for a kernel function.
403 if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D))
Tanya Lattner0df579e2012-07-09 22:06:01 +0000404 EmitOpenCLKernelMetadata(FD, Fn);
Peter Collingbournef315fa82011-02-14 01:42:53 +0000405 }
406
Daniel Dunbar55e87422008-11-11 02:29:29 +0000407 llvm::BasicBlock *EntryBB = createBasicBlock("entry", CurFn);
Daniel Dunbar5ca20842008-09-09 21:00:17 +0000408
Chris Lattner41110242008-06-17 18:05:57 +0000409 // Create a marker to make it easy to insert allocas into the entryblock
410 // later. Don't create this with the builder, because we don't want it
411 // folded.
Chris Lattner77b89b82010-06-27 07:15:29 +0000412 llvm::Value *Undef = llvm::UndefValue::get(Int32Ty);
413 AllocaInsertPt = new llvm::BitCastInst(Undef, Int32Ty, "", EntryBB);
Chris Lattnerf1466842009-03-22 00:24:14 +0000414 if (Builder.isNamePreserving())
415 AllocaInsertPt->setName("allocapt");
Mike Stump1eb44332009-09-09 15:08:12 +0000416
John McCallf1549f62010-07-06 01:34:17 +0000417 ReturnBlock = getJumpDestInCurrentScope("return");
Mike Stump1eb44332009-09-09 15:08:12 +0000418
Chris Lattner41110242008-06-17 18:05:57 +0000419 Builder.SetInsertPoint(EntryBB);
Mike Stump1eb44332009-09-09 15:08:12 +0000420
Sanjiv Guptaaf994172008-07-04 11:04:26 +0000421 // Emit subprogram debug descriptor.
Anders Carlssone896d982009-02-13 08:11:52 +0000422 if (CGDebugInfo *DI = getDebugInfo()) {
Jordan Rosebea522f2013-03-08 21:51:21 +0000423 SmallVector<QualType, 16> ArgTypes;
Eric Christopher06253662011-10-21 23:30:10 +0000424 for (FunctionArgList::const_iterator i = Args.begin(), e = Args.end();
425 i != e; ++i) {
Jordan Rosebea522f2013-03-08 21:51:21 +0000426 ArgTypes.push_back((*i)->getType());
Eric Christopher06253662011-10-21 23:30:10 +0000427 }
428
John McCalle23cf432010-12-14 08:05:40 +0000429 QualType FnType =
Jordan Rosebea522f2013-03-08 21:51:21 +0000430 getContext().getFunctionType(RetTy, ArgTypes,
John McCalle23cf432010-12-14 08:05:40 +0000431 FunctionProtoType::ExtProtoInfo());
432
Daniel Dunbar2284ac92008-10-18 18:22:23 +0000433 DI->setLocation(StartLoc);
Devang Patel9c6c3a02010-01-14 00:36:21 +0000434 DI->EmitFunctionStart(GD, FnType, CurFn, Builder);
Sanjiv Guptaaf994172008-07-04 11:04:26 +0000435 }
436
Daniel Dunbara18652f2011-02-10 17:32:22 +0000437 if (ShouldInstrumentFunction())
438 EmitFunctionInstrumentation("__cyg_profile_func_enter");
Chris Lattner7255a2d2010-06-22 00:03:40 +0000439
Roman Divackybe4c8702011-02-10 16:52:03 +0000440 if (CGM.getCodeGenOpts().InstrumentForProfiling)
441 EmitMCountInstrumentation();
442
Eli Friedmanb17daf92009-12-04 02:43:40 +0000443 if (RetTy->isVoidType()) {
444 // Void type; nothing to return.
445 ReturnValue = 0;
446 } else if (CurFnInfo->getReturnInfo().getKind() == ABIArgInfo::Indirect &&
John McCall9d232c82013-03-07 21:37:08 +0000447 !hasScalarEvaluationKind(CurFnInfo->getReturnType())) {
Eli Friedmanb17daf92009-12-04 02:43:40 +0000448 // Indirect aggregate return; emit returned value directly into sret slot.
Daniel Dunbar647a1ec2010-02-16 19:45:20 +0000449 // This reduces code size, and affects correctness in C++.
Eli Friedmanb17daf92009-12-04 02:43:40 +0000450 ReturnValue = CurFn->arg_begin();
451 } else {
Daniel Dunbar647a1ec2010-02-16 19:45:20 +0000452 ReturnValue = CreateIRTemp(RetTy, "retval");
John McCallf85e1932011-06-15 23:02:42 +0000453
454 // Tell the epilog emitter to autorelease the result. We do this
455 // now so that various specialized functions can suppress it
456 // during their IR-generation.
David Blaikie4e4d0842012-03-11 07:00:24 +0000457 if (getLangOpts().ObjCAutoRefCount &&
John McCallf85e1932011-06-15 23:02:42 +0000458 !CurFnInfo->isReturnsRetained() &&
459 RetTy->isObjCRetainableType())
460 AutoreleaseResult = true;
Eli Friedmanb17daf92009-12-04 02:43:40 +0000461 }
462
Mike Stumpcce3d4f2009-12-07 23:38:24 +0000463 EmitStartEHSpec(CurCodeDecl);
John McCallf85e1932011-06-15 23:02:42 +0000464
465 PrologueCleanupDepth = EHStack.stable_begin();
Daniel Dunbar88b53962009-02-02 22:03:45 +0000466 EmitFunctionProlog(*CurFnInfo, CurFn, Args);
Mike Stump1eb44332009-09-09 15:08:12 +0000467
Eli Friedmancec5ebd2012-02-11 02:57:39 +0000468 if (D && isa<CXXMethodDecl>(D) && cast<CXXMethodDecl>(D)->isInstance()) {
John McCall4c40d982010-08-31 07:33:07 +0000469 CGM.getCXXABI().EmitInstanceFunctionProlog(*this);
Eli Friedmancec5ebd2012-02-11 02:57:39 +0000470 const CXXMethodDecl *MD = cast<CXXMethodDecl>(D);
471 if (MD->getParent()->isLambda() &&
472 MD->getOverloadedOperator() == OO_Call) {
473 // We're in a lambda; figure out the captures.
474 MD->getParent()->getCaptureFields(LambdaCaptureFields,
475 LambdaThisCaptureField);
476 if (LambdaThisCaptureField) {
477 // If this lambda captures this, load it.
Eli Friedman377ecc72012-04-16 03:54:45 +0000478 QualType LambdaTagType =
479 getContext().getTagDeclType(LambdaThisCaptureField->getParent());
480 LValue LambdaLV = MakeNaturalAlignAddrLValue(CXXABIThisValue,
481 LambdaTagType);
482 LValue ThisLValue = EmitLValueForField(LambdaLV,
483 LambdaThisCaptureField);
Eli Friedmancec5ebd2012-02-11 02:57:39 +0000484 CXXThisValue = EmitLoadOfLValue(ThisLValue).getScalarVal();
485 }
486 } else {
487 // Not in a lambda; just use 'this' from the method.
488 // FIXME: Should we generate a new load for each use of 'this'? The
489 // fast register allocator would be happier...
490 CXXThisValue = CXXABIThisValue;
491 }
492 }
John McCall25049412010-02-16 22:04:33 +0000493
Anders Carlsson751358f2008-12-20 21:28:43 +0000494 // If any of the arguments have a variably modified type, make sure to
495 // emit the type size.
496 for (FunctionArgList::const_iterator i = Args.begin(), e = Args.end();
497 i != e; ++i) {
Eli Friedmanf5bf9122012-11-14 22:09:59 +0000498 const VarDecl *VD = *i;
499
500 // Dig out the type as written from ParmVarDecls; it's unclear whether
501 // the standard (C99 6.9.1p10) requires this, but we're following the
502 // precedent set by gcc.
503 QualType Ty;
504 if (const ParmVarDecl *PVD = dyn_cast<ParmVarDecl>(VD))
505 Ty = PVD->getOriginalType();
506 else
507 Ty = VD->getType();
Anders Carlsson751358f2008-12-20 21:28:43 +0000508
509 if (Ty->isVariablyModifiedType())
John McCallbc8d40d2011-06-24 21:55:10 +0000510 EmitVariablyModifiedType(Ty);
Anders Carlsson751358f2008-12-20 21:28:43 +0000511 }
Eric Christopher73fb3502011-10-13 21:45:18 +0000512 // Emit a location at the end of the prologue.
513 if (CGDebugInfo *DI = getDebugInfo())
514 DI->EmitLocation(Builder, StartLoc);
Daniel Dunbar7c086512008-09-09 23:14:03 +0000515}
Eli Friedmaneb4b7052008-08-25 21:31:01 +0000516
John McCall9fc6a772010-02-19 09:25:03 +0000517void CodeGenFunction::EmitFunctionBody(FunctionArgList &Args) {
518 const FunctionDecl *FD = cast<FunctionDecl>(CurGD.getDecl());
Douglas Gregor06a9f362010-05-01 20:49:11 +0000519 assert(FD->getBody());
David Blaikiea6504852013-01-26 22:16:26 +0000520 if (const CompoundStmt *S = dyn_cast<CompoundStmt>(FD->getBody()))
521 EmitCompoundStmtWithoutScope(*S);
522 else
523 EmitStmt(FD->getBody());
John McCalla355e072010-02-18 03:17:58 +0000524}
525
John McCall39dad532010-08-03 22:46:07 +0000526/// Tries to mark the given function nounwind based on the
527/// non-existence of any throwing calls within it. We believe this is
528/// lightweight enough to do at -O0.
529static void TryMarkNoThrow(llvm::Function *F) {
John McCallb3a29f12010-08-11 22:38:33 +0000530 // LLVM treats 'nounwind' on a function as part of the type, so we
531 // can't do this on functions that can be overwritten.
532 if (F->mayBeOverridden()) return;
533
John McCall39dad532010-08-03 22:46:07 +0000534 for (llvm::Function::iterator FI = F->begin(), FE = F->end(); FI != FE; ++FI)
535 for (llvm::BasicBlock::iterator
536 BI = FI->begin(), BE = FI->end(); BI != BE; ++BI)
Bill Wendling285cfd82011-09-19 20:31:14 +0000537 if (llvm::CallInst *Call = dyn_cast<llvm::CallInst>(&*BI)) {
John McCall39dad532010-08-03 22:46:07 +0000538 if (!Call->doesNotThrow())
539 return;
Bill Wendling285cfd82011-09-19 20:31:14 +0000540 } else if (isa<llvm::ResumeInst>(&*BI)) {
541 return;
542 }
Bill Wendlingfac63102012-10-10 03:13:20 +0000543 F->setDoesNotThrow();
John McCall39dad532010-08-03 22:46:07 +0000544}
545
John McCalld26bc762011-03-09 04:27:21 +0000546void CodeGenFunction::GenerateCode(GlobalDecl GD, llvm::Function *Fn,
547 const CGFunctionInfo &FnInfo) {
Anders Carlsson0ff8baf2009-09-11 00:07:24 +0000548 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000549
Anders Carlssone896d982009-02-13 08:11:52 +0000550 // Check if we should generate debug info for this function.
Alexey Samsonova240df22012-10-16 07:22:28 +0000551 if (!FD->hasAttr<NoDebugAttr>())
552 maybeInitializeDebugInfo();
Mike Stump1eb44332009-09-09 15:08:12 +0000553
Daniel Dunbar7c086512008-09-09 23:14:03 +0000554 FunctionArgList Args;
John McCall4c40d982010-08-31 07:33:07 +0000555 QualType ResTy = FD->getResultType();
Mike Stump1eb44332009-09-09 15:08:12 +0000556
Mike Stump6a1e0eb2009-12-04 23:26:17 +0000557 CurGD = GD;
John McCall4c40d982010-08-31 07:33:07 +0000558 if (isa<CXXMethodDecl>(FD) && cast<CXXMethodDecl>(FD)->isInstance())
559 CGM.getCXXABI().BuildInstanceFunctionParams(*this, ResTy, Args);
Mike Stump1eb44332009-09-09 15:08:12 +0000560
Chad Rosier6e94f6c2012-02-18 00:37:07 +0000561 for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i)
562 Args.push_back(FD->getParamDecl(i));
Daniel Dunbaraf05bb92008-08-26 08:29:31 +0000563
John McCalla355e072010-02-18 03:17:58 +0000564 SourceRange BodyRange;
565 if (Stmt *Body = FD->getBody()) BodyRange = Body->getSourceRange();
Anders Carlsson4365bba2009-11-06 02:55:43 +0000566
John McCalla355e072010-02-18 03:17:58 +0000567 // Emit the standard function prologue.
John McCalld26bc762011-03-09 04:27:21 +0000568 StartFunction(GD, ResTy, Fn, FnInfo, Args, BodyRange.getBegin());
Anders Carlsson4365bba2009-11-06 02:55:43 +0000569
John McCalla355e072010-02-18 03:17:58 +0000570 // Generate the body of the function.
John McCall9fc6a772010-02-19 09:25:03 +0000571 if (isa<CXXDestructorDecl>(FD))
572 EmitDestructorBody(Args);
573 else if (isa<CXXConstructorDecl>(FD))
574 EmitConstructorBody(Args);
Richard Smith7edf9e32012-11-01 22:30:59 +0000575 else if (getLangOpts().CUDA &&
Peter Collingbournea4ae2292011-10-06 18:51:56 +0000576 !CGM.getCodeGenOpts().CUDAIsDevice &&
577 FD->hasAttr<CUDAGlobalAttr>())
578 CGM.getCUDARuntime().EmitDeviceStubBody(*this, Args);
Eli Friedmanbd89f8c2012-02-16 01:37:33 +0000579 else if (isa<CXXConversionDecl>(FD) &&
Douglas Gregor27dd7d92012-02-17 03:02:34 +0000580 cast<CXXConversionDecl>(FD)->isLambdaToBlockPointerConversion()) {
581 // The lambda conversion to block pointer is special; the semantics can't be
582 // expressed in the AST, so IRGen needs to special-case it.
583 EmitLambdaToBlockPointerBody(Args);
584 } else if (isa<CXXMethodDecl>(FD) &&
585 cast<CXXMethodDecl>(FD)->isLambdaStaticInvoker()) {
586 // The lambda "__invoke" function is special, because it forwards or
587 // clones the body of the function call operator (but is actually static).
588 EmitLambdaStaticInvokeFunction(cast<CXXMethodDecl>(FD));
Lang Hames56c00c42013-02-17 07:22:09 +0000589 } else if (FD->isDefaulted() && isa<CXXMethodDecl>(FD) &&
590 cast<CXXMethodDecl>(FD)->isCopyAssignmentOperator()) {
591 // Implicit copy-assignment gets the same special treatment as implicit
592 // copy-constructors.
593 emitImplicitAssignmentOperatorBody(Args);
Eli Friedmanbd89f8c2012-02-16 01:37:33 +0000594 }
John McCall9fc6a772010-02-19 09:25:03 +0000595 else
596 EmitFunctionBody(Args);
Anders Carlsson1851a122010-02-07 19:45:40 +0000597
Richard Smith36ef0d52012-10-04 23:52:29 +0000598 // C++11 [stmt.return]p2:
599 // Flowing off the end of a function [...] results in undefined behavior in
600 // a value-returning function.
601 // C11 6.9.1p12:
602 // If the '}' that terminates a function is reached, and the value of the
603 // function call is used by the caller, the behavior is undefined.
Richard Smith7edf9e32012-11-01 22:30:59 +0000604 if (getLangOpts().CPlusPlus && !FD->hasImplicitReturnZero() &&
Richard Smith36ef0d52012-10-04 23:52:29 +0000605 !FD->getResultType()->isVoidType() && Builder.GetInsertBlock()) {
Will Dietz4f45bc02013-01-18 11:30:38 +0000606 if (SanOpts->Return)
Richard Smith4def70d2012-10-09 19:52:38 +0000607 EmitCheck(Builder.getFalse(), "missing_return",
608 EmitCheckSourceLocation(FD->getLocation()),
Dmitri Gribenkocfa88f82013-01-12 19:30:44 +0000609 ArrayRef<llvm::Value *>(), CRK_Unrecoverable);
Richard Smith802cd5b2012-10-15 00:23:07 +0000610 else if (CGM.getCodeGenOpts().OptimizationLevel == 0)
611 Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::trap));
Richard Smith36ef0d52012-10-04 23:52:29 +0000612 Builder.CreateUnreachable();
613 Builder.ClearInsertionPoint();
614 }
615
John McCalla355e072010-02-18 03:17:58 +0000616 // Emit the standard function epilogue.
617 FinishFunction(BodyRange.getEnd());
John McCall39dad532010-08-03 22:46:07 +0000618
619 // If we haven't marked the function nothrow through other means, do
620 // a quick pass now to see if we can.
621 if (!CurFn->doesNotThrow())
622 TryMarkNoThrow(CurFn);
Chris Lattner41110242008-06-17 18:05:57 +0000623}
624
Chris Lattner0946ccd2008-11-11 07:41:27 +0000625/// ContainsLabel - Return true if the statement contains a label in it. If
626/// this statement is not executed normally, it not containing a label means
627/// that we can just remove the code.
628bool CodeGenFunction::ContainsLabel(const Stmt *S, bool IgnoreCaseStmts) {
629 // Null statement, not a label!
630 if (S == 0) return false;
Mike Stump1eb44332009-09-09 15:08:12 +0000631
Chris Lattner0946ccd2008-11-11 07:41:27 +0000632 // If this is a label, we have to emit the code, consider something like:
633 // if (0) { ... foo: bar(); } goto foo;
Chris Lattneref425a62011-02-28 00:18:40 +0000634 //
635 // TODO: If anyone cared, we could track __label__'s, since we know that you
636 // can't jump to one from outside their declared region.
Chris Lattner0946ccd2008-11-11 07:41:27 +0000637 if (isa<LabelStmt>(S))
638 return true;
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000639
Chris Lattner0946ccd2008-11-11 07:41:27 +0000640 // If this is a case/default statement, and we haven't seen a switch, we have
641 // to emit the code.
642 if (isa<SwitchCase>(S) && !IgnoreCaseStmts)
643 return true;
Mike Stump1eb44332009-09-09 15:08:12 +0000644
Chris Lattner0946ccd2008-11-11 07:41:27 +0000645 // If this is a switch statement, we want to ignore cases below it.
646 if (isa<SwitchStmt>(S))
647 IgnoreCaseStmts = true;
Mike Stump1eb44332009-09-09 15:08:12 +0000648
Chris Lattner0946ccd2008-11-11 07:41:27 +0000649 // Scan subexpressions for verboten labels.
John McCall7502c1d2011-02-13 04:07:26 +0000650 for (Stmt::const_child_range I = S->children(); I; ++I)
Chris Lattner0946ccd2008-11-11 07:41:27 +0000651 if (ContainsLabel(*I, IgnoreCaseStmts))
652 return true;
Mike Stump1eb44332009-09-09 15:08:12 +0000653
Chris Lattner0946ccd2008-11-11 07:41:27 +0000654 return false;
655}
656
Chris Lattneref425a62011-02-28 00:18:40 +0000657/// containsBreak - Return true if the statement contains a break out of it.
658/// If the statement (recursively) contains a switch or loop with a break
659/// inside of it, this is fine.
660bool CodeGenFunction::containsBreak(const Stmt *S) {
661 // Null statement, not a label!
662 if (S == 0) return false;
663
664 // If this is a switch or loop that defines its own break scope, then we can
665 // include it and anything inside of it.
666 if (isa<SwitchStmt>(S) || isa<WhileStmt>(S) || isa<DoStmt>(S) ||
667 isa<ForStmt>(S))
Chris Lattner2bef7f52011-02-28 00:42:31 +0000668 return false;
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000669
Chris Lattner2bef7f52011-02-28 00:42:31 +0000670 if (isa<BreakStmt>(S))
Chris Lattneref425a62011-02-28 00:18:40 +0000671 return true;
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000672
Chris Lattneref425a62011-02-28 00:18:40 +0000673 // Scan subexpressions for verboten breaks.
674 for (Stmt::const_child_range I = S->children(); I; ++I)
675 if (containsBreak(*I))
676 return true;
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000677
Chris Lattneref425a62011-02-28 00:18:40 +0000678 return false;
679}
680
Chris Lattner31a09842008-11-12 08:04:58 +0000681
Chris Lattnerc2c90012011-02-27 23:02:32 +0000682/// ConstantFoldsToSimpleInteger - If the specified expression does not fold
683/// to a constant, or if it does but contains a label, return false. If it
684/// constant folds return true and set the boolean result in Result.
685bool CodeGenFunction::ConstantFoldsToSimpleInteger(const Expr *Cond,
686 bool &ResultBool) {
Richard Trieue1ecdc12012-07-23 20:21:35 +0000687 llvm::APSInt ResultInt;
Chris Lattneref425a62011-02-28 00:18:40 +0000688 if (!ConstantFoldsToSimpleInteger(Cond, ResultInt))
689 return false;
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000690
Chris Lattneref425a62011-02-28 00:18:40 +0000691 ResultBool = ResultInt.getBoolValue();
692 return true;
693}
694
695/// ConstantFoldsToSimpleInteger - If the specified expression does not fold
696/// to a constant, or if it does but contains a label, return false. If it
697/// constant folds return true and set the folded value.
698bool CodeGenFunction::
Richard Trieue1ecdc12012-07-23 20:21:35 +0000699ConstantFoldsToSimpleInteger(const Expr *Cond, llvm::APSInt &ResultInt) {
Daniel Dunbar36bc14c2008-11-12 22:37:10 +0000700 // FIXME: Rename and handle conversion of other evaluatable things
701 // to bool.
Richard Smith80d4b552011-12-28 19:48:30 +0000702 llvm::APSInt Int;
703 if (!Cond->EvaluateAsInt(Int, getContext()))
Chris Lattnerc2c90012011-02-27 23:02:32 +0000704 return false; // Not foldable, not integer or not fully evaluatable.
Richard Smith80d4b552011-12-28 19:48:30 +0000705
Chris Lattner31a09842008-11-12 08:04:58 +0000706 if (CodeGenFunction::ContainsLabel(Cond))
Chris Lattnerc2c90012011-02-27 23:02:32 +0000707 return false; // Contains a label.
Richard Smith80d4b552011-12-28 19:48:30 +0000708
709 ResultInt = Int;
Chris Lattnerc2c90012011-02-27 23:02:32 +0000710 return true;
Chris Lattner31a09842008-11-12 08:04:58 +0000711}
712
713
Chris Lattneref425a62011-02-28 00:18:40 +0000714
Chris Lattner31a09842008-11-12 08:04:58 +0000715/// EmitBranchOnBoolExpr - Emit a branch on a boolean condition (e.g. for an if
716/// statement) to the specified blocks. Based on the condition, this might try
717/// to simplify the codegen of the conditional based on the branch.
718///
719void CodeGenFunction::EmitBranchOnBoolExpr(const Expr *Cond,
720 llvm::BasicBlock *TrueBlock,
721 llvm::BasicBlock *FalseBlock) {
Peter Collingbournef111d932011-04-15 00:35:48 +0000722 Cond = Cond->IgnoreParens();
Mike Stump1eb44332009-09-09 15:08:12 +0000723
Chris Lattner31a09842008-11-12 08:04:58 +0000724 if (const BinaryOperator *CondBOp = dyn_cast<BinaryOperator>(Cond)) {
725 // Handle X && Y in a condition.
John McCall2de56d12010-08-25 11:45:40 +0000726 if (CondBOp->getOpcode() == BO_LAnd) {
Chris Lattner31a09842008-11-12 08:04:58 +0000727 // If we have "1 && X", simplify the code. "0 && X" would have constant
728 // folded if the case was simple enough.
Bill Wendlinge3eb83b2011-03-04 21:46:03 +0000729 bool ConstantBool = false;
Chris Lattnerc2c90012011-02-27 23:02:32 +0000730 if (ConstantFoldsToSimpleInteger(CondBOp->getLHS(), ConstantBool) &&
731 ConstantBool) {
Chris Lattner31a09842008-11-12 08:04:58 +0000732 // br(1 && X) -> br(X).
733 return EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock);
734 }
Mike Stump1eb44332009-09-09 15:08:12 +0000735
Chris Lattner31a09842008-11-12 08:04:58 +0000736 // If we have "X && 1", simplify the code to use an uncond branch.
737 // "X && 0" would have been constant folded to 0.
Chris Lattnerc2c90012011-02-27 23:02:32 +0000738 if (ConstantFoldsToSimpleInteger(CondBOp->getRHS(), ConstantBool) &&
739 ConstantBool) {
Chris Lattner31a09842008-11-12 08:04:58 +0000740 // br(X && 1) -> br(X).
741 return EmitBranchOnBoolExpr(CondBOp->getLHS(), TrueBlock, FalseBlock);
742 }
Mike Stump1eb44332009-09-09 15:08:12 +0000743
Chris Lattner31a09842008-11-12 08:04:58 +0000744 // Emit the LHS as a conditional. If the LHS conditional is false, we
745 // want to jump to the FalseBlock.
Daniel Dunbar9615ecb2008-11-13 01:38:36 +0000746 llvm::BasicBlock *LHSTrue = createBasicBlock("land.lhs.true");
John McCall150b4622011-01-26 04:00:11 +0000747
748 ConditionalEvaluation eval(*this);
Chris Lattner31a09842008-11-12 08:04:58 +0000749 EmitBranchOnBoolExpr(CondBOp->getLHS(), LHSTrue, FalseBlock);
750 EmitBlock(LHSTrue);
Mike Stump1eb44332009-09-09 15:08:12 +0000751
Anders Carlsson08e9e452010-01-24 00:20:05 +0000752 // Any temporaries created here are conditional.
John McCall150b4622011-01-26 04:00:11 +0000753 eval.begin(*this);
Chris Lattner31a09842008-11-12 08:04:58 +0000754 EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock);
John McCall150b4622011-01-26 04:00:11 +0000755 eval.end(*this);
Anders Carlsson08e9e452010-01-24 00:20:05 +0000756
Chris Lattner31a09842008-11-12 08:04:58 +0000757 return;
Chris Lattnerc2c90012011-02-27 23:02:32 +0000758 }
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000759
Chris Lattnerc2c90012011-02-27 23:02:32 +0000760 if (CondBOp->getOpcode() == BO_LOr) {
Chris Lattner31a09842008-11-12 08:04:58 +0000761 // If we have "0 || X", simplify the code. "1 || X" would have constant
762 // folded if the case was simple enough.
Bill Wendlinge3eb83b2011-03-04 21:46:03 +0000763 bool ConstantBool = false;
Chris Lattnerc2c90012011-02-27 23:02:32 +0000764 if (ConstantFoldsToSimpleInteger(CondBOp->getLHS(), ConstantBool) &&
765 !ConstantBool) {
Chris Lattner31a09842008-11-12 08:04:58 +0000766 // br(0 || X) -> br(X).
767 return EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock);
768 }
Mike Stump1eb44332009-09-09 15:08:12 +0000769
Chris Lattner31a09842008-11-12 08:04:58 +0000770 // If we have "X || 0", simplify the code to use an uncond branch.
771 // "X || 1" would have been constant folded to 1.
Chris Lattnerc2c90012011-02-27 23:02:32 +0000772 if (ConstantFoldsToSimpleInteger(CondBOp->getRHS(), ConstantBool) &&
773 !ConstantBool) {
Chris Lattner31a09842008-11-12 08:04:58 +0000774 // br(X || 0) -> br(X).
775 return EmitBranchOnBoolExpr(CondBOp->getLHS(), TrueBlock, FalseBlock);
776 }
Mike Stump1eb44332009-09-09 15:08:12 +0000777
Chris Lattner31a09842008-11-12 08:04:58 +0000778 // Emit the LHS as a conditional. If the LHS conditional is true, we
779 // want to jump to the TrueBlock.
Daniel Dunbar9615ecb2008-11-13 01:38:36 +0000780 llvm::BasicBlock *LHSFalse = createBasicBlock("lor.lhs.false");
John McCall150b4622011-01-26 04:00:11 +0000781
782 ConditionalEvaluation eval(*this);
Chris Lattner31a09842008-11-12 08:04:58 +0000783 EmitBranchOnBoolExpr(CondBOp->getLHS(), TrueBlock, LHSFalse);
784 EmitBlock(LHSFalse);
Mike Stump1eb44332009-09-09 15:08:12 +0000785
Anders Carlsson08e9e452010-01-24 00:20:05 +0000786 // Any temporaries created here are conditional.
John McCall150b4622011-01-26 04:00:11 +0000787 eval.begin(*this);
Chris Lattner31a09842008-11-12 08:04:58 +0000788 EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock);
John McCall150b4622011-01-26 04:00:11 +0000789 eval.end(*this);
Anders Carlsson08e9e452010-01-24 00:20:05 +0000790
Chris Lattner31a09842008-11-12 08:04:58 +0000791 return;
792 }
Chris Lattner552f4c42008-11-12 08:13:36 +0000793 }
Mike Stump1eb44332009-09-09 15:08:12 +0000794
Chris Lattner552f4c42008-11-12 08:13:36 +0000795 if (const UnaryOperator *CondUOp = dyn_cast<UnaryOperator>(Cond)) {
796 // br(!x, t, f) -> br(x, f, t)
John McCall2de56d12010-08-25 11:45:40 +0000797 if (CondUOp->getOpcode() == UO_LNot)
Chris Lattner552f4c42008-11-12 08:13:36 +0000798 return EmitBranchOnBoolExpr(CondUOp->getSubExpr(), FalseBlock, TrueBlock);
Chris Lattner31a09842008-11-12 08:04:58 +0000799 }
Mike Stump1eb44332009-09-09 15:08:12 +0000800
Daniel Dunbar09b14892008-11-12 10:30:32 +0000801 if (const ConditionalOperator *CondOp = dyn_cast<ConditionalOperator>(Cond)) {
Eli Friedmandf33a352012-02-14 03:54:45 +0000802 // br(c ? x : y, t, f) -> br(c, br(x, t, f), br(y, t, f))
803 llvm::BasicBlock *LHSBlock = createBasicBlock("cond.true");
804 llvm::BasicBlock *RHSBlock = createBasicBlock("cond.false");
Daniel Dunbar09b14892008-11-12 10:30:32 +0000805
Eli Friedmandf33a352012-02-14 03:54:45 +0000806 ConditionalEvaluation cond(*this);
807 EmitBranchOnBoolExpr(CondOp->getCond(), LHSBlock, RHSBlock);
John McCall150b4622011-01-26 04:00:11 +0000808
Eli Friedmandf33a352012-02-14 03:54:45 +0000809 cond.begin(*this);
810 EmitBlock(LHSBlock);
811 EmitBranchOnBoolExpr(CondOp->getLHS(), TrueBlock, FalseBlock);
812 cond.end(*this);
John McCall150b4622011-01-26 04:00:11 +0000813
Eli Friedmandf33a352012-02-14 03:54:45 +0000814 cond.begin(*this);
815 EmitBlock(RHSBlock);
816 EmitBranchOnBoolExpr(CondOp->getRHS(), TrueBlock, FalseBlock);
817 cond.end(*this);
John McCall150b4622011-01-26 04:00:11 +0000818
Eli Friedmandf33a352012-02-14 03:54:45 +0000819 return;
Daniel Dunbar09b14892008-11-12 10:30:32 +0000820 }
821
Chris Lattner31a09842008-11-12 08:04:58 +0000822 // Emit the code with the fully general case.
823 llvm::Value *CondV = EvaluateExprAsBool(Cond);
824 Builder.CreateCondBr(CondV, TrueBlock, FalseBlock);
825}
826
Daniel Dunbar488e9932008-08-16 00:56:44 +0000827/// ErrorUnsupported - Print out an error that codegen doesn't support the
Chris Lattnerdc5e8262007-12-02 01:43:38 +0000828/// specified stmt yet.
Daniel Dunbar90df4b62008-09-04 03:43:08 +0000829void CodeGenFunction::ErrorUnsupported(const Stmt *S, const char *Type,
830 bool OmitOnError) {
831 CGM.ErrorUnsupported(S, Type, OmitOnError);
Chris Lattnerdc5e8262007-12-02 01:43:38 +0000832}
833
John McCall71433252011-02-01 21:35:06 +0000834/// emitNonZeroVLAInit - Emit the "zero" initialization of a
835/// variable-length array whose elements have a non-zero bit-pattern.
836///
James Dennett2ee5ba32012-06-15 22:10:14 +0000837/// \param baseType the inner-most element type of the array
John McCall71433252011-02-01 21:35:06 +0000838/// \param src - a char* pointing to the bit-pattern for a single
839/// base element of the array
840/// \param sizeInChars - the total size of the VLA, in chars
John McCall71433252011-02-01 21:35:06 +0000841static void emitNonZeroVLAInit(CodeGenFunction &CGF, QualType baseType,
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000842 llvm::Value *dest, llvm::Value *src,
John McCall71433252011-02-01 21:35:06 +0000843 llvm::Value *sizeInChars) {
844 std::pair<CharUnits,CharUnits> baseSizeAndAlign
845 = CGF.getContext().getTypeInfoInChars(baseType);
846
847 CGBuilderTy &Builder = CGF.Builder;
848
849 llvm::Value *baseSizeInChars
850 = llvm::ConstantInt::get(CGF.IntPtrTy, baseSizeAndAlign.first.getQuantity());
851
Chris Lattner2acc6e32011-07-18 04:24:23 +0000852 llvm::Type *i8p = Builder.getInt8PtrTy();
John McCall71433252011-02-01 21:35:06 +0000853
854 llvm::Value *begin = Builder.CreateBitCast(dest, i8p, "vla.begin");
855 llvm::Value *end = Builder.CreateInBoundsGEP(dest, sizeInChars, "vla.end");
856
857 llvm::BasicBlock *originBB = CGF.Builder.GetInsertBlock();
858 llvm::BasicBlock *loopBB = CGF.createBasicBlock("vla-init.loop");
859 llvm::BasicBlock *contBB = CGF.createBasicBlock("vla-init.cont");
860
861 // Make a loop over the VLA. C99 guarantees that the VLA element
862 // count must be nonzero.
863 CGF.EmitBlock(loopBB);
864
Jay Foadbbf3bac2011-03-30 11:28:58 +0000865 llvm::PHINode *cur = Builder.CreatePHI(i8p, 2, "vla.cur");
John McCall71433252011-02-01 21:35:06 +0000866 cur->addIncoming(begin, originBB);
867
868 // memcpy the individual element bit-pattern.
869 Builder.CreateMemCpy(cur, src, baseSizeInChars,
870 baseSizeAndAlign.second.getQuantity(),
871 /*volatile*/ false);
872
873 // Go to the next element.
874 llvm::Value *next = Builder.CreateConstInBoundsGEP1_32(cur, 1, "vla.next");
875
876 // Leave if that's the end of the VLA.
877 llvm::Value *done = Builder.CreateICmpEQ(next, end, "vla-init.isdone");
878 Builder.CreateCondBr(done, contBB, loopBB);
879 cur->addIncoming(next, loopBB);
880
881 CGF.EmitBlock(contBB);
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000882}
John McCall71433252011-02-01 21:35:06 +0000883
Anders Carlsson1884eb02010-05-22 17:35:42 +0000884void
885CodeGenFunction::EmitNullInitialization(llvm::Value *DestPtr, QualType Ty) {
Anders Carlsson0d7c5832010-05-03 01:20:20 +0000886 // Ignore empty classes in C++.
Richard Smith7edf9e32012-11-01 22:30:59 +0000887 if (getLangOpts().CPlusPlus) {
Anders Carlsson0d7c5832010-05-03 01:20:20 +0000888 if (const RecordType *RT = Ty->getAs<RecordType>()) {
889 if (cast<CXXRecordDecl>(RT->getDecl())->isEmpty())
890 return;
891 }
892 }
John McCall90217182010-08-07 08:21:30 +0000893
894 // Cast the dest ptr to the appropriate i8 pointer type.
895 unsigned DestAS =
896 cast<llvm::PointerType>(DestPtr->getType())->getAddressSpace();
Chris Lattner2acc6e32011-07-18 04:24:23 +0000897 llvm::Type *BP = Builder.getInt8PtrTy(DestAS);
Anders Carlsson3d8400d2008-08-30 19:51:14 +0000898 if (DestPtr->getType() != BP)
Benjamin Kramer578faa82011-09-27 21:06:10 +0000899 DestPtr = Builder.CreateBitCast(DestPtr, BP);
Anders Carlsson3d8400d2008-08-30 19:51:14 +0000900
901 // Get size and alignment info for this aggregate.
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000902 std::pair<CharUnits, CharUnits> TypeInfo =
Ken Dyck79be76c2011-04-22 17:51:05 +0000903 getContext().getTypeInfoInChars(Ty);
904 CharUnits Size = TypeInfo.first;
905 CharUnits Align = TypeInfo.second;
Anders Carlsson3d8400d2008-08-30 19:51:14 +0000906
John McCall5576d9b2011-01-14 10:37:58 +0000907 llvm::Value *SizeVal;
John McCall71433252011-02-01 21:35:06 +0000908 const VariableArrayType *vla;
Mike Stump1eb44332009-09-09 15:08:12 +0000909
John McCall5576d9b2011-01-14 10:37:58 +0000910 // Don't bother emitting a zero-byte memset.
Ken Dyck79be76c2011-04-22 17:51:05 +0000911 if (Size.isZero()) {
John McCall5576d9b2011-01-14 10:37:58 +0000912 // But note that getTypeInfo returns 0 for a VLA.
913 if (const VariableArrayType *vlaType =
914 dyn_cast_or_null<VariableArrayType>(
915 getContext().getAsArrayType(Ty))) {
John McCallbc8d40d2011-06-24 21:55:10 +0000916 QualType eltType;
917 llvm::Value *numElts;
918 llvm::tie(numElts, eltType) = getVLASize(vlaType);
919
920 SizeVal = numElts;
921 CharUnits eltSize = getContext().getTypeSizeInChars(eltType);
922 if (!eltSize.isOne())
923 SizeVal = Builder.CreateNUWMul(SizeVal, CGM.getSize(eltSize));
John McCall71433252011-02-01 21:35:06 +0000924 vla = vlaType;
John McCall5576d9b2011-01-14 10:37:58 +0000925 } else {
926 return;
927 }
928 } else {
John McCallbc8d40d2011-06-24 21:55:10 +0000929 SizeVal = CGM.getSize(Size);
John McCall71433252011-02-01 21:35:06 +0000930 vla = 0;
John McCall5576d9b2011-01-14 10:37:58 +0000931 }
John McCall90217182010-08-07 08:21:30 +0000932
933 // If the type contains a pointer to data member we can't memset it to zero.
934 // Instead, create a null constant and copy it to the destination.
John McCall71433252011-02-01 21:35:06 +0000935 // TODO: there are other patterns besides zero that we can usefully memset,
936 // like -1, which happens to be the pattern used by member-pointers.
John McCallf16aa102010-08-22 21:01:12 +0000937 if (!CGM.getTypes().isZeroInitializable(Ty)) {
John McCall71433252011-02-01 21:35:06 +0000938 // For a VLA, emit a single element, then splat that over the VLA.
939 if (vla) Ty = getContext().getBaseElementType(vla);
John McCall5576d9b2011-01-14 10:37:58 +0000940
John McCall90217182010-08-07 08:21:30 +0000941 llvm::Constant *NullConstant = CGM.EmitNullConstant(Ty);
942
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000943 llvm::GlobalVariable *NullVariable =
John McCall90217182010-08-07 08:21:30 +0000944 new llvm::GlobalVariable(CGM.getModule(), NullConstant->getType(),
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000945 /*isConstant=*/true,
John McCall90217182010-08-07 08:21:30 +0000946 llvm::GlobalVariable::PrivateLinkage,
Chris Lattner5f9e2722011-07-23 10:55:15 +0000947 NullConstant, Twine());
John McCall90217182010-08-07 08:21:30 +0000948 llvm::Value *SrcPtr =
949 Builder.CreateBitCast(NullVariable, Builder.getInt8PtrTy());
950
John McCall71433252011-02-01 21:35:06 +0000951 if (vla) return emitNonZeroVLAInit(*this, Ty, DestPtr, SrcPtr, SizeVal);
952
John McCall90217182010-08-07 08:21:30 +0000953 // Get and call the appropriate llvm.memcpy overload.
Ken Dyck79be76c2011-04-22 17:51:05 +0000954 Builder.CreateMemCpy(DestPtr, SrcPtr, SizeVal, Align.getQuantity(), false);
John McCall90217182010-08-07 08:21:30 +0000955 return;
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000956 }
957
John McCall90217182010-08-07 08:21:30 +0000958 // Otherwise, just memset the whole thing to zero. This is legal
959 // because in LLVM, all default initializers (other than the ones we just
960 // handled above) are guaranteed to have a bit pattern of all zeros.
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000961 Builder.CreateMemSet(DestPtr, Builder.getInt8(0), SizeVal,
Ken Dyck79be76c2011-04-22 17:51:05 +0000962 Align.getQuantity(), false);
Anders Carlsson3d8400d2008-08-30 19:51:14 +0000963}
964
Chris Lattnerad8dcf42011-02-17 07:39:24 +0000965llvm::BlockAddress *CodeGenFunction::GetAddrOfLabel(const LabelDecl *L) {
Chris Lattnerd9becd12009-10-28 23:59:40 +0000966 // Make sure that there is a block for the indirect goto.
967 if (IndirectBranch == 0)
968 GetIndirectGotoBlock();
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000969
John McCallff8e1152010-07-23 21:56:41 +0000970 llvm::BasicBlock *BB = getJumpDestForLabel(L).getBlock();
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000971
Chris Lattnerd9becd12009-10-28 23:59:40 +0000972 // Make sure the indirect branch includes all of the address-taken blocks.
973 IndirectBranch->addDestination(BB);
974 return llvm::BlockAddress::get(CurFn, BB);
Chris Lattner3d00fdc2009-10-13 06:55:33 +0000975}
976
977llvm::BasicBlock *CodeGenFunction::GetIndirectGotoBlock() {
Chris Lattnerd9becd12009-10-28 23:59:40 +0000978 // If we already made the indirect branch for indirect goto, return its block.
979 if (IndirectBranch) return IndirectBranch->getParent();
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000980
Chris Lattnerd9becd12009-10-28 23:59:40 +0000981 CGBuilderTy TmpBuilder(createBasicBlock("indirectgoto"));
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000982
Chris Lattner3d00fdc2009-10-13 06:55:33 +0000983 // Create the PHI node that indirect gotos will add entries to.
Jay Foadbbf3bac2011-03-30 11:28:58 +0000984 llvm::Value *DestVal = TmpBuilder.CreatePHI(Int8PtrTy, 0,
985 "indirect.goto.dest");
Michael Ilseman9dce4b32012-12-04 00:29:55 +0000986
Chris Lattnerd9becd12009-10-28 23:59:40 +0000987 // Create the indirect branch instruction.
988 IndirectBranch = TmpBuilder.CreateIndirectBr(DestVal);
989 return IndirectBranch->getParent();
Daniel Dunbar0ffb1252008-08-04 16:51:22 +0000990}
Anders Carlssonddf7cac2008-11-04 05:30:00 +0000991
John McCallbdc4d802011-07-09 01:37:26 +0000992/// Computes the length of an array in elements, as well as the base
993/// element type and a properly-typed first element pointer.
994llvm::Value *CodeGenFunction::emitArrayLength(const ArrayType *origArrayType,
995 QualType &baseType,
996 llvm::Value *&addr) {
997 const ArrayType *arrayType = origArrayType;
998
999 // If it's a VLA, we have to load the stored size. Note that
1000 // this is the size of the VLA in bytes, not its size in elements.
1001 llvm::Value *numVLAElements = 0;
1002 if (isa<VariableArrayType>(arrayType)) {
1003 numVLAElements = getVLASize(cast<VariableArrayType>(arrayType)).first;
1004
1005 // Walk into all VLAs. This doesn't require changes to addr,
1006 // which has type T* where T is the first non-VLA element type.
1007 do {
1008 QualType elementType = arrayType->getElementType();
1009 arrayType = getContext().getAsArrayType(elementType);
1010
1011 // If we only have VLA components, 'addr' requires no adjustment.
1012 if (!arrayType) {
1013 baseType = elementType;
1014 return numVLAElements;
1015 }
1016 } while (isa<VariableArrayType>(arrayType));
1017
1018 // We get out here only if we find a constant array type
1019 // inside the VLA.
1020 }
1021
1022 // We have some number of constant-length arrays, so addr should
1023 // have LLVM type [M x [N x [...]]]*. Build a GEP that walks
1024 // down to the first element of addr.
Chris Lattner5f9e2722011-07-23 10:55:15 +00001025 SmallVector<llvm::Value*, 8> gepIndices;
John McCallbdc4d802011-07-09 01:37:26 +00001026
1027 // GEP down to the array type.
1028 llvm::ConstantInt *zero = Builder.getInt32(0);
1029 gepIndices.push_back(zero);
1030
John McCallbdc4d802011-07-09 01:37:26 +00001031 uint64_t countFromCLAs = 1;
Richard Smith1664d542012-04-22 05:51:36 +00001032 QualType eltType;
John McCallbdc4d802011-07-09 01:37:26 +00001033
Chris Lattner2acc6e32011-07-18 04:24:23 +00001034 llvm::ArrayType *llvmArrayType =
Richard Smith1664d542012-04-22 05:51:36 +00001035 dyn_cast<llvm::ArrayType>(
John McCallbdc4d802011-07-09 01:37:26 +00001036 cast<llvm::PointerType>(addr->getType())->getElementType());
Richard Smith1664d542012-04-22 05:51:36 +00001037 while (llvmArrayType) {
John McCallbdc4d802011-07-09 01:37:26 +00001038 assert(isa<ConstantArrayType>(arrayType));
1039 assert(cast<ConstantArrayType>(arrayType)->getSize().getZExtValue()
1040 == llvmArrayType->getNumElements());
1041
1042 gepIndices.push_back(zero);
1043 countFromCLAs *= llvmArrayType->getNumElements();
Richard Smith1664d542012-04-22 05:51:36 +00001044 eltType = arrayType->getElementType();
John McCallbdc4d802011-07-09 01:37:26 +00001045
1046 llvmArrayType =
1047 dyn_cast<llvm::ArrayType>(llvmArrayType->getElementType());
John McCallbdc4d802011-07-09 01:37:26 +00001048 arrayType = getContext().getAsArrayType(arrayType->getElementType());
Richard Smith1664d542012-04-22 05:51:36 +00001049 assert((!llvmArrayType || arrayType) &&
1050 "LLVM and Clang types are out-of-synch");
John McCallbdc4d802011-07-09 01:37:26 +00001051 }
1052
Richard Smith1664d542012-04-22 05:51:36 +00001053 if (arrayType) {
1054 // From this point onwards, the Clang array type has been emitted
1055 // as some other type (probably a packed struct). Compute the array
1056 // size, and just emit the 'begin' expression as a bitcast.
1057 while (arrayType) {
1058 countFromCLAs *=
1059 cast<ConstantArrayType>(arrayType)->getSize().getZExtValue();
1060 eltType = arrayType->getElementType();
1061 arrayType = getContext().getAsArrayType(eltType);
1062 }
John McCallbdc4d802011-07-09 01:37:26 +00001063
Micah Villmow956a5a12012-10-25 15:39:14 +00001064 unsigned AddressSpace = addr->getType()->getPointerAddressSpace();
Richard Smith1664d542012-04-22 05:51:36 +00001065 llvm::Type *BaseType = ConvertType(eltType)->getPointerTo(AddressSpace);
1066 addr = Builder.CreateBitCast(addr, BaseType, "array.begin");
1067 } else {
1068 // Create the actual GEP.
1069 addr = Builder.CreateInBoundsGEP(addr, gepIndices, "array.begin");
1070 }
1071
1072 baseType = eltType;
John McCallbdc4d802011-07-09 01:37:26 +00001073
1074 llvm::Value *numElements
1075 = llvm::ConstantInt::get(SizeTy, countFromCLAs);
1076
1077 // If we had any VLA dimensions, factor them in.
1078 if (numVLAElements)
1079 numElements = Builder.CreateNUWMul(numVLAElements, numElements);
1080
1081 return numElements;
1082}
1083
John McCallbc8d40d2011-06-24 21:55:10 +00001084std::pair<llvm::Value*, QualType>
1085CodeGenFunction::getVLASize(QualType type) {
1086 const VariableArrayType *vla = getContext().getAsVariableArrayType(type);
1087 assert(vla && "type was not a variable array type!");
1088 return getVLASize(vla);
Anders Carlssonf666b772008-12-20 20:27:15 +00001089}
Anders Carlssondcc90d82008-12-12 07:19:02 +00001090
John McCallbc8d40d2011-06-24 21:55:10 +00001091std::pair<llvm::Value*, QualType>
1092CodeGenFunction::getVLASize(const VariableArrayType *type) {
1093 // The number of elements so far; always size_t.
1094 llvm::Value *numElements = 0;
1095
1096 QualType elementType;
1097 do {
1098 elementType = type->getElementType();
1099 llvm::Value *vlaSize = VLASizeMap[type->getSizeExpr()];
1100 assert(vlaSize && "no size for VLA!");
1101 assert(vlaSize->getType() == SizeTy);
1102
1103 if (!numElements) {
1104 numElements = vlaSize;
1105 } else {
1106 // It's undefined behavior if this wraps around, so mark it that way.
Richard Smith930c05c2012-10-10 01:11:12 +00001107 // FIXME: Teach -fcatch-undefined-behavior to trap this.
John McCallbc8d40d2011-06-24 21:55:10 +00001108 numElements = Builder.CreateNUWMul(numElements, vlaSize);
1109 }
1110 } while ((type = getContext().getAsVariableArrayType(elementType)));
1111
1112 return std::pair<llvm::Value*,QualType>(numElements, elementType);
1113}
1114
1115void CodeGenFunction::EmitVariablyModifiedType(QualType type) {
1116 assert(type->isVariablyModifiedType() &&
Anders Carlsson60d35412008-12-20 20:46:34 +00001117 "Must pass variably modified type to EmitVLASizes!");
Mike Stump1eb44332009-09-09 15:08:12 +00001118
Daniel Dunbard286f052009-07-19 06:58:07 +00001119 EnsureInsertPoint();
Mike Stump1eb44332009-09-09 15:08:12 +00001120
John McCallbc8d40d2011-06-24 21:55:10 +00001121 // We're going to walk down into the type and look for VLA
1122 // expressions.
John McCallbc8d40d2011-06-24 21:55:10 +00001123 do {
1124 assert(type->isVariablyModifiedType());
Mike Stump1eb44332009-09-09 15:08:12 +00001125
John McCallbc8d40d2011-06-24 21:55:10 +00001126 const Type *ty = type.getTypePtr();
1127 switch (ty->getTypeClass()) {
Abramo Bagnara06284c12012-01-07 10:52:36 +00001128
John McCallbc8d40d2011-06-24 21:55:10 +00001129#define TYPE(Class, Base)
1130#define ABSTRACT_TYPE(Class, Base)
Abramo Bagnara06284c12012-01-07 10:52:36 +00001131#define NON_CANONICAL_TYPE(Class, Base)
John McCallbc8d40d2011-06-24 21:55:10 +00001132#define DEPENDENT_TYPE(Class, Base) case Type::Class:
Abramo Bagnara06284c12012-01-07 10:52:36 +00001133#define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base)
John McCallbc8d40d2011-06-24 21:55:10 +00001134#include "clang/AST/TypeNodes.def"
Abramo Bagnara06284c12012-01-07 10:52:36 +00001135 llvm_unreachable("unexpected dependent type!");
Mike Stump1eb44332009-09-09 15:08:12 +00001136
John McCallbc8d40d2011-06-24 21:55:10 +00001137 // These types are never variably-modified.
1138 case Type::Builtin:
1139 case Type::Complex:
1140 case Type::Vector:
1141 case Type::ExtVector:
1142 case Type::Record:
1143 case Type::Enum:
Abramo Bagnara5ff53b22012-01-11 08:19:46 +00001144 case Type::Elaborated:
1145 case Type::TemplateSpecialization:
John McCallbc8d40d2011-06-24 21:55:10 +00001146 case Type::ObjCObject:
1147 case Type::ObjCInterface:
1148 case Type::ObjCObjectPointer:
1149 llvm_unreachable("type class is never variably-modified!");
Mike Stump1eb44332009-09-09 15:08:12 +00001150
John McCallbc8d40d2011-06-24 21:55:10 +00001151 case Type::Pointer:
1152 type = cast<PointerType>(ty)->getPointeeType();
1153 break;
Mike Stump1eb44332009-09-09 15:08:12 +00001154
John McCallbc8d40d2011-06-24 21:55:10 +00001155 case Type::BlockPointer:
1156 type = cast<BlockPointerType>(ty)->getPointeeType();
1157 break;
1158
1159 case Type::LValueReference:
1160 case Type::RValueReference:
1161 type = cast<ReferenceType>(ty)->getPointeeType();
1162 break;
1163
1164 case Type::MemberPointer:
1165 type = cast<MemberPointerType>(ty)->getPointeeType();
1166 break;
1167
1168 case Type::ConstantArray:
1169 case Type::IncompleteArray:
1170 // Losing element qualification here is fine.
1171 type = cast<ArrayType>(ty)->getElementType();
1172 break;
1173
1174 case Type::VariableArray: {
1175 // Losing element qualification here is fine.
1176 const VariableArrayType *vat = cast<VariableArrayType>(ty);
1177
1178 // Unknown size indication requires no size computation.
1179 // Otherwise, evaluate and record it.
1180 if (const Expr *size = vat->getSizeExpr()) {
1181 // It's possible that we might have emitted this already,
1182 // e.g. with a typedef and a pointer to it.
1183 llvm::Value *&entry = VLASizeMap[size];
1184 if (!entry) {
Richard Smith930c05c2012-10-10 01:11:12 +00001185 llvm::Value *Size = EmitScalarExpr(size);
1186
1187 // C11 6.7.6.2p5:
1188 // If the size is an expression that is not an integer constant
1189 // expression [...] each time it is evaluated it shall have a value
1190 // greater than zero.
Will Dietz4f45bc02013-01-18 11:30:38 +00001191 if (SanOpts->VLABound &&
Richard Smithd6396a62012-11-05 22:21:05 +00001192 size->getType()->isSignedIntegerType()) {
Richard Smith930c05c2012-10-10 01:11:12 +00001193 llvm::Value *Zero = llvm::Constant::getNullValue(Size->getType());
1194 llvm::Constant *StaticArgs[] = {
1195 EmitCheckSourceLocation(size->getLocStart()),
1196 EmitCheckTypeDescriptor(size->getType())
1197 };
1198 EmitCheck(Builder.CreateICmpSGT(Size, Zero),
Will Dietzad954812012-12-02 19:50:33 +00001199 "vla_bound_not_positive", StaticArgs, Size,
1200 CRK_Recoverable);
Richard Smith930c05c2012-10-10 01:11:12 +00001201 }
1202
John McCallbc8d40d2011-06-24 21:55:10 +00001203 // Always zexting here would be wrong if it weren't
1204 // undefined behavior to have a negative bound.
Richard Smithbf43f2f2012-10-10 01:12:11 +00001205 entry = Builder.CreateIntCast(Size, SizeTy, /*signed*/ false);
John McCallbc8d40d2011-06-24 21:55:10 +00001206 }
1207 }
1208 type = vat->getElementType();
1209 break;
Anders Carlsson60d35412008-12-20 20:46:34 +00001210 }
Mike Stump1eb44332009-09-09 15:08:12 +00001211
Abramo Bagnara06284c12012-01-07 10:52:36 +00001212 case Type::FunctionProto:
John McCallbc8d40d2011-06-24 21:55:10 +00001213 case Type::FunctionNoProto:
1214 type = cast<FunctionType>(ty)->getResultType();
1215 break;
Eli Friedmanb001de72011-10-06 23:00:33 +00001216
Abramo Bagnara5ff53b22012-01-11 08:19:46 +00001217 case Type::Paren:
1218 case Type::TypeOf:
1219 case Type::UnaryTransform:
1220 case Type::Attributed:
1221 case Type::SubstTemplateTypeParm:
1222 // Keep walking after single level desugaring.
1223 type = type.getSingleStepDesugaredType(getContext());
1224 break;
1225
1226 case Type::Typedef:
1227 case Type::Decltype:
1228 case Type::Auto:
1229 // Stop walking: nothing to do.
1230 return;
1231
1232 case Type::TypeOfExpr:
1233 // Stop walking: emit typeof expression.
1234 EmitIgnoredExpr(cast<TypeOfExprType>(ty)->getUnderlyingExpr());
1235 return;
1236
Eli Friedmanb001de72011-10-06 23:00:33 +00001237 case Type::Atomic:
1238 type = cast<AtomicType>(ty)->getValueType();
1239 break;
John McCallbc8d40d2011-06-24 21:55:10 +00001240 }
1241 } while (type->isVariablyModifiedType());
Anders Carlssondcc90d82008-12-12 07:19:02 +00001242}
Eli Friedman4fd0aa52009-01-20 17:46:04 +00001243
1244llvm::Value* CodeGenFunction::EmitVAListRef(const Expr* E) {
Dan Gohmanbc07a552010-10-29 22:47:07 +00001245 if (getContext().getBuiltinVaListType()->isArrayType())
Eli Friedman4fd0aa52009-01-20 17:46:04 +00001246 return EmitScalarExpr(E);
Eli Friedman4fd0aa52009-01-20 17:46:04 +00001247 return EmitLValue(E).getAddress();
1248}
Anders Carlsson6ccc4762009-02-07 22:53:43 +00001249
Michael Ilseman9dce4b32012-12-04 00:29:55 +00001250void CodeGenFunction::EmitDeclRefExprDbgValue(const DeclRefExpr *E,
John McCall189d6ef2010-10-09 01:34:31 +00001251 llvm::Constant *Init) {
Devang Patel25c2c8f2010-08-10 17:53:33 +00001252 assert (Init && "Invalid DeclRefExpr initializer!");
1253 if (CGDebugInfo *Dbg = getDebugInfo())
Douglas Gregor4cdad312012-10-23 20:05:01 +00001254 if (CGM.getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo)
Alexey Samsonovfd00eec2012-05-04 07:39:27 +00001255 Dbg->EmitGlobalVariable(E->getDecl(), Init);
Devang Patel8d308382010-08-10 07:24:25 +00001256}
John McCall56ca35d2011-02-17 10:25:35 +00001257
1258CodeGenFunction::PeepholeProtection
1259CodeGenFunction::protectFromPeepholes(RValue rvalue) {
1260 // At the moment, the only aggressive peephole we do in IR gen
1261 // is trunc(zext) folding, but if we add more, we can easily
1262 // extend this protection.
1263
1264 if (!rvalue.isScalar()) return PeepholeProtection();
1265 llvm::Value *value = rvalue.getScalarVal();
1266 if (!isa<llvm::ZExtInst>(value)) return PeepholeProtection();
1267
1268 // Just make an extra bitcast.
1269 assert(HaveInsertPoint());
1270 llvm::Instruction *inst = new llvm::BitCastInst(value, value->getType(), "",
1271 Builder.GetInsertBlock());
1272
1273 PeepholeProtection protection;
1274 protection.Inst = inst;
1275 return protection;
1276}
1277
1278void CodeGenFunction::unprotectFromPeepholes(PeepholeProtection protection) {
1279 if (!protection.Inst) return;
1280
1281 // In theory, we could try to duplicate the peepholes now, but whatever.
1282 protection.Inst->eraseFromParent();
1283}
Julien Lerouge77f68bb2011-09-09 22:41:49 +00001284
1285llvm::Value *CodeGenFunction::EmitAnnotationCall(llvm::Value *AnnotationFn,
1286 llvm::Value *AnnotatedVal,
Dmitri Gribenkocfa88f82013-01-12 19:30:44 +00001287 StringRef AnnotationStr,
Julien Lerouge77f68bb2011-09-09 22:41:49 +00001288 SourceLocation Location) {
1289 llvm::Value *Args[4] = {
1290 AnnotatedVal,
1291 Builder.CreateBitCast(CGM.EmitAnnotationString(AnnotationStr), Int8PtrTy),
1292 Builder.CreateBitCast(CGM.EmitAnnotationUnit(Location), Int8PtrTy),
1293 CGM.EmitAnnotationLineNo(Location)
1294 };
1295 return Builder.CreateCall(AnnotationFn, Args);
1296}
1297
1298void CodeGenFunction::EmitVarAnnotations(const VarDecl *D, llvm::Value *V) {
1299 assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute");
1300 // FIXME We create a new bitcast for every annotation because that's what
1301 // llvm-gcc was doing.
1302 for (specific_attr_iterator<AnnotateAttr>
1303 ai = D->specific_attr_begin<AnnotateAttr>(),
1304 ae = D->specific_attr_end<AnnotateAttr>(); ai != ae; ++ai)
1305 EmitAnnotationCall(CGM.getIntrinsic(llvm::Intrinsic::var_annotation),
1306 Builder.CreateBitCast(V, CGM.Int8PtrTy, V->getName()),
1307 (*ai)->getAnnotation(), D->getLocation());
1308}
1309
1310llvm::Value *CodeGenFunction::EmitFieldAnnotations(const FieldDecl *D,
1311 llvm::Value *V) {
1312 assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute");
1313 llvm::Type *VTy = V->getType();
1314 llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::ptr_annotation,
1315 CGM.Int8PtrTy);
1316
1317 for (specific_attr_iterator<AnnotateAttr>
1318 ai = D->specific_attr_begin<AnnotateAttr>(),
1319 ae = D->specific_attr_end<AnnotateAttr>(); ai != ae; ++ai) {
1320 // FIXME Always emit the cast inst so we can differentiate between
1321 // annotation on the first field of a struct and annotation on the struct
1322 // itself.
1323 if (VTy != CGM.Int8PtrTy)
1324 V = Builder.Insert(new llvm::BitCastInst(V, CGM.Int8PtrTy));
1325 V = EmitAnnotationCall(F, V, (*ai)->getAnnotation(), D->getLocation());
1326 V = Builder.CreateBitCast(V, VTy);
1327 }
1328
1329 return V;
1330}