1//===--- CodeGenModule.cpp - Emit LLVM Code from ASTs for a Module --------===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This coordinates the per-module state used while generating code.
11//
12//===----------------------------------------------------------------------===//
13
14#include "CodeGenModule.h"
15#include "CGDebugInfo.h"
16#include "CodeGenFunction.h"
17#include "CGCall.h"
18#include "CGObjCRuntime.h"
19#include "Mangle.h"
20#include "clang/Frontend/CompileOptions.h"
21#include "clang/AST/ASTContext.h"
22#include "clang/AST/DeclObjC.h"
23#include "clang/AST/DeclCXX.h"
24#include "clang/Basic/Builtins.h"
25#include "clang/Basic/Diagnostic.h"
26#include "clang/Basic/SourceManager.h"
27#include "clang/Basic/TargetInfo.h"
28#include "clang/Basic/ConvertUTF.h"
29#include "llvm/CallingConv.h"
30#include "llvm/Module.h"
31#include "llvm/Intrinsics.h"
32#include "llvm/Target/TargetData.h"
33using namespace clang;
34using namespace CodeGen;
35
36
37CodeGenModule::CodeGenModule(ASTContext &C, const CompileOptions &compileOpts,
38 llvm::Module &M, const llvm::TargetData &TD,
39 Diagnostic &diags)
40 : BlockModule(C, M, TD, Types, *this), Context(C),
41 Features(C.getLangOptions()), CompileOpts(compileOpts), TheModule(M),
42 TheTargetData(TD), Diags(diags), Types(C, M, TD), Runtime(0),
43 MemCpyFn(0), MemMoveFn(0), MemSetFn(0), CFConstantStringClassRef(0) {
44
45 if (!Features.ObjC1)
46 Runtime = 0;
47 else if (!Features.NeXTRuntime)
48 Runtime = CreateGNUObjCRuntime(*this);
49 else if (Features.ObjCNonFragileABI)
50 Runtime = CreateMacNonFragileABIObjCRuntime(*this);
51 else
52 Runtime = CreateMacObjCRuntime(*this);
53
54 // If debug info generation is enabled, create the CGDebugInfo object.
55 DebugInfo = CompileOpts.DebugInfo ? new CGDebugInfo(this) : 0;
56}
57
58CodeGenModule::~CodeGenModule() {
59 delete Runtime;
60 delete DebugInfo;
61}
62
63void CodeGenModule::Release() {
64 EmitDeferred();
65 if (Runtime)
66 if (llvm::Function *ObjCInitFunction = Runtime->ModuleInitFunction())
67 AddGlobalCtor(ObjCInitFunction);
68 EmitCtorList(GlobalCtors, "llvm.global_ctors");
69 EmitCtorList(GlobalDtors, "llvm.global_dtors");
70 EmitAnnotations();
71 EmitLLVMUsed();
72}
73
74/// ErrorUnsupported - Print out an error that codegen doesn't support the
75/// specified stmt yet.
76void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type,
77 bool OmitOnError) {
78 if (OmitOnError && getDiags().hasErrorOccurred())
79 return;
80 unsigned DiagID = getDiags().getCustomDiagID(Diagnostic::Error,
81 "cannot compile this %0 yet");
82 std::string Msg = Type;
83 getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID)
84 << Msg << S->getSourceRange();
85}
86
87/// ErrorUnsupported - Print out an error that codegen doesn't support the
88/// specified decl yet.
89void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type,
90 bool OmitOnError) {
91 if (OmitOnError && getDiags().hasErrorOccurred())
92 return;
93 unsigned DiagID = getDiags().getCustomDiagID(Diagnostic::Error,
94 "cannot compile this %0 yet");
95 std::string Msg = Type;
96 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg;
97}
98
99LangOptions::VisibilityMode
100CodeGenModule::getDeclVisibilityMode(const Decl *D) const {
101 if (const VarDecl *VD = dyn_cast<VarDecl>(D))
102 if (VD->getStorageClass() == VarDecl::PrivateExtern)
103 return LangOptions::Hidden;
104
105 if (const VisibilityAttr *attr = D->getAttr<VisibilityAttr>(getContext())) {
106 switch (attr->getVisibility()) {
107 default: assert(0 && "Unknown visibility!");
108 case VisibilityAttr::DefaultVisibility:
109 return LangOptions::Default;
110 case VisibilityAttr::HiddenVisibility:
111 return LangOptions::Hidden;
112 case VisibilityAttr::ProtectedVisibility:
113 return LangOptions::Protected;
114 }
115 }
116
117 return getLangOptions().getVisibilityMode();
118}
119
120void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV,
121 const Decl *D) const {
122 // Internal definitions always have default visibility.
123 if (GV->hasLocalLinkage()) {
124 GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
125 return;
126 }
127
128 switch (getDeclVisibilityMode(D)) {
129 default: assert(0 && "Unknown visibility!");
130 case LangOptions::Default:
131 return GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
132 case LangOptions::Hidden:
133 return GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
134 case LangOptions::Protected:
135 return GV->setVisibility(llvm::GlobalValue::ProtectedVisibility);
136 }
137}
138
139const char *CodeGenModule::getMangledName(const GlobalDecl &GD) {
140 const NamedDecl *ND = GD.getDecl();
141
142 if (const CXXConstructorDecl *D = dyn_cast<CXXConstructorDecl>(ND))
143 return getMangledCXXCtorName(D, GD.getCtorType());
144 if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(ND))
145 return getMangledCXXDtorName(D, GD.getDtorType());
146
147 return getMangledName(ND);
148}
149
150/// \brief Retrieves the mangled name for the given declaration.
151///
152/// If the given declaration requires a mangled name, returns an
153/// const char* containing the mangled name. Otherwise, returns
154/// the unmangled name.
155///
156const char *CodeGenModule::getMangledName(const NamedDecl *ND) {
157 // In C, functions with no attributes never need to be mangled. Fastpath them.
158 if (!getLangOptions().CPlusPlus && !ND->hasAttrs()) {
159 assert(ND->getIdentifier() && "Attempt to mangle unnamed decl.");
160 return ND->getNameAsCString();
161 }
162
163 llvm::SmallString<256> Name;
164 llvm::raw_svector_ostream Out(Name);
165 if (!mangleName(ND, Context, Out)) {
166 assert(ND->getIdentifier() && "Attempt to mangle unnamed decl.");
167 return ND->getNameAsCString();
168 }
169
170 Name += '\0';
171 return UniqueMangledName(Name.begin(), Name.end());
172}
173
174const char *CodeGenModule::UniqueMangledName(const char *NameStart,
175 const char *NameEnd) {
176 assert(*(NameEnd - 1) == '\0' && "Mangled name must be null terminated!");
177
178 return MangledNames.GetOrCreateValue(NameStart, NameEnd).getKeyData();
179}
180
181/// AddGlobalCtor - Add a function to the list that will be called before
182/// main() runs.
183void CodeGenModule::AddGlobalCtor(llvm::Function * Ctor, int Priority) {
184 // FIXME: Type coercion of void()* types.
185 GlobalCtors.push_back(std::make_pair(Ctor, Priority));
186}
187
188/// AddGlobalDtor - Add a function to the list that will be called
189/// when the module is unloaded.
190void CodeGenModule::AddGlobalDtor(llvm::Function * Dtor, int Priority) {
191 // FIXME: Type coercion of void()* types.
192 GlobalDtors.push_back(std::make_pair(Dtor, Priority));
193}
194
195void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) {
196 // Ctor function type is void()*.
197 llvm::FunctionType* CtorFTy =
198 llvm::FunctionType::get(llvm::Type::VoidTy,
199 std::vector<const llvm::Type*>(),
200 false);
201 llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy);
202
203 // Get the type of a ctor entry, { i32, void ()* }.
204 llvm::StructType* CtorStructTy =
205 llvm::StructType::get(llvm::Type::Int32Ty,
206 llvm::PointerType::getUnqual(CtorFTy), NULL);
207
208 // Construct the constructor and destructor arrays.
209 std::vector<llvm::Constant*> Ctors;
210 for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) {
211 std::vector<llvm::Constant*> S;
212 S.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, I->second, false));
213 S.push_back(llvm::ConstantExpr::getBitCast(I->first, CtorPFTy));
214 Ctors.push_back(llvm::ConstantStruct::get(CtorStructTy, S));
215 }
216
217 if (!Ctors.empty()) {
218 llvm::ArrayType *AT = llvm::ArrayType::get(CtorStructTy, Ctors.size());
219 new llvm::GlobalVariable(AT, false,
220 llvm::GlobalValue::AppendingLinkage,
221 llvm::ConstantArray::get(AT, Ctors),
222 GlobalName,
223 &TheModule);
224 }
225}
226
227void CodeGenModule::EmitAnnotations() {
228 if (Annotations.empty())
229 return;
230
231 // Create a new global variable for the ConstantStruct in the Module.
232 llvm::Constant *Array =
233 llvm::ConstantArray::get(llvm::ArrayType::get(Annotations[0]->getType(),
234 Annotations.size()),
235 Annotations);
236 llvm::GlobalValue *gv =
237 new llvm::GlobalVariable(Array->getType(), false,
238 llvm::GlobalValue::AppendingLinkage, Array,
239 "llvm.global.annotations", &TheModule);
240 gv->setSection("llvm.metadata");
241}
242
243static CodeGenModule::GVALinkage
244GetLinkageForFunction(ASTContext &Context, const FunctionDecl *FD,
245 const LangOptions &Features) {
246 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
247 // C++ member functions defined inside the class are always inline.
248 if (MD->isInline() || !MD->isOutOfLine())
249 return CodeGenModule::GVA_CXXInline;
250
251 return CodeGenModule::GVA_StrongExternal;
252 }
253
254 // "static" functions get internal linkage.
255 if (FD->getStorageClass() == FunctionDecl::Static)
256 return CodeGenModule::GVA_Internal;
257
258 if (!FD->isInline())
259 return CodeGenModule::GVA_StrongExternal;
260
261 // If the inline function explicitly has the GNU inline attribute on it, or if
262 // this is C89 mode, we use to GNU semantics.
263 if (!Features.C99 && !Features.CPlusPlus) {
264 // extern inline in GNU mode is like C99 inline.
265 if (FD->getStorageClass() == FunctionDecl::Extern)
266 return CodeGenModule::GVA_C99Inline;
267 // Normal inline is a strong symbol.
268 return CodeGenModule::GVA_StrongExternal;
269 } else if (FD->hasActiveGNUInlineAttribute(Context)) {
270 // GCC in C99 mode seems to use a different decision-making
271 // process for extern inline, which factors in previous
272 // declarations.
273 if (FD->isExternGNUInline(Context))
274 return CodeGenModule::GVA_C99Inline;
275 // Normal inline is a strong symbol.
276 return CodeGenModule::GVA_StrongExternal;
277 }
278
279 // The definition of inline changes based on the language. Note that we
280 // have already handled "static inline" above, with the GVA_Internal case.
281 if (Features.CPlusPlus) // inline and extern inline.
282 return CodeGenModule::GVA_CXXInline;
283
284 assert(Features.C99 && "Must be in C99 mode if not in C89 or C++ mode");
285 if (FD->isC99InlineDefinition())
286 return CodeGenModule::GVA_C99Inline;
287
288 return CodeGenModule::GVA_StrongExternal;
289}
290
291/// SetFunctionDefinitionAttributes - Set attributes for a global.
292///
293/// FIXME: This is currently only done for aliases and functions, but not for
294/// variables (these details are set in EmitGlobalVarDefinition for variables).
295void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D,
296 llvm::GlobalValue *GV) {
297 GVALinkage Linkage = GetLinkageForFunction(getContext(), D, Features);
298
299 if (Linkage == GVA_Internal) {
300 GV->setLinkage(llvm::Function::InternalLinkage);
301 } else if (D->hasAttr<DLLExportAttr>(getContext())) {
302 GV->setLinkage(llvm::Function::DLLExportLinkage);
303 } else if (D->hasAttr<WeakAttr>(getContext())) {
304 GV->setLinkage(llvm::Function::WeakAnyLinkage);
305 } else if (Linkage == GVA_C99Inline) {
306 // In C99 mode, 'inline' functions are guaranteed to have a strong
307 // definition somewhere else, so we can use available_externally linkage.
308 GV->setLinkage(llvm::Function::AvailableExternallyLinkage);
309 } else if (Linkage == GVA_CXXInline) {
310 // In C++, the compiler has to emit a definition in every translation unit
311 // that references the function. We should use linkonce_odr because
312 // a) if all references in this translation unit are optimized away, we
313 // don't need to codegen it. b) if the function persists, it needs to be
314 // merged with other definitions. c) C++ has the ODR, so we know the
315 // definition is dependable.
316 GV->setLinkage(llvm::Function::LinkOnceODRLinkage);
317 } else {
318 assert(Linkage == GVA_StrongExternal);
319 // Otherwise, we have strong external linkage.
320 GV->setLinkage(llvm::Function::ExternalLinkage);
321 }
322
323 SetCommonAttributes(D, GV);
324}
325
326void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D,
327 const CGFunctionInfo &Info,
328 llvm::Function *F) {
329 AttributeListType AttributeList;
330 ConstructAttributeList(Info, D, AttributeList);
331
332 F->setAttributes(llvm::AttrListPtr::get(AttributeList.begin(),
333 AttributeList.size()));
334
335 // Set the appropriate calling convention for the Function.
336 if (D->hasAttr<FastCallAttr>(getContext()))
337 F->setCallingConv(llvm::CallingConv::X86_FastCall);
338
339 if (D->hasAttr<StdCallAttr>(getContext()))
340 F->setCallingConv(llvm::CallingConv::X86_StdCall);
341}
342
343void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
344 llvm::Function *F) {
345 if (!Features.Exceptions && !Features.ObjCNonFragileABI)
346 F->addFnAttr(llvm::Attribute::NoUnwind);
347
348 if (D->hasAttr<AlwaysInlineAttr>(getContext()))
349 F->addFnAttr(llvm::Attribute::AlwaysInline);
350
351 if (D->hasAttr<NoinlineAttr>(getContext()))
352 F->addFnAttr(llvm::Attribute::NoInline);
353}
354
355void CodeGenModule::SetCommonAttributes(const Decl *D,
356 llvm::GlobalValue *GV) {
357 setGlobalVisibility(GV, D);
358
359 if (D->hasAttr<UsedAttr>(getContext()))
360 AddUsedGlobal(GV);
361
362 if (const SectionAttr *SA = D->getAttr<SectionAttr>(getContext()))
363 GV->setSection(SA->getName());
364}
365
366void CodeGenModule::SetInternalFunctionAttributes(const Decl *D,
367 llvm::Function *F,
368 const CGFunctionInfo &FI) {
369 SetLLVMFunctionAttributes(D, FI, F);
370 SetLLVMFunctionAttributesForDefinition(D, F);
371
372 F->setLinkage(llvm::Function::InternalLinkage);
373
374 SetCommonAttributes(D, F);
375}
376
377void CodeGenModule::SetFunctionAttributes(const FunctionDecl *FD,
378 llvm::Function *F,
379 bool IsIncompleteFunction) {
380 if (!IsIncompleteFunction)
381 SetLLVMFunctionAttributes(FD, getTypes().getFunctionInfo(FD), F);
382
383 // Only a few attributes are set on declarations; these may later be
384 // overridden by a definition.
385
386 if (FD->hasAttr<DLLImportAttr>(getContext())) {
387 F->setLinkage(llvm::Function::DLLImportLinkage);
388 } else if (FD->hasAttr<WeakAttr>(getContext()) ||
389 FD->hasAttr<WeakImportAttr>(getContext())) {
390 // "extern_weak" is overloaded in LLVM; we probably should have
391 // separate linkage types for this.
392 F->setLinkage(llvm::Function::ExternalWeakLinkage);
393 } else {
394 F->setLinkage(llvm::Function::ExternalLinkage);
395 }
396
397 if (const SectionAttr *SA = FD->getAttr<SectionAttr>(getContext()))
398 F->setSection(SA->getName());
399}
400
401void CodeGenModule::AddUsedGlobal(llvm::GlobalValue *GV) {
402 assert(!GV->isDeclaration() &&
403 "Only globals with definition can force usage.");
404 LLVMUsed.push_back(GV);
405}
406
407void CodeGenModule::EmitLLVMUsed() {
408 // Don't create llvm.used if there is no need.
409 // FIXME. Runtime indicates that there might be more 'used' symbols; but not
410 // necessariy. So, this test is not accurate for emptiness.
411 if (LLVMUsed.empty() && !Runtime)
412 return;
413
414 llvm::Type *i8PTy = llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
415
416 // Convert LLVMUsed to what ConstantArray needs.
417 std::vector<llvm::Constant*> UsedArray;
418 UsedArray.resize(LLVMUsed.size());
419 for (unsigned i = 0, e = LLVMUsed.size(); i != e; ++i) {
420 UsedArray[i] =
421 llvm::ConstantExpr::getBitCast(cast<llvm::Constant>(&*LLVMUsed[i]), i8PTy);
422 }
423
424 if (Runtime)
425 Runtime->MergeMetadataGlobals(UsedArray);
426 if (UsedArray.empty())
427 return;
428 llvm::ArrayType *ATy = llvm::ArrayType::get(i8PTy, UsedArray.size());
429
430 llvm::GlobalVariable *GV =
431 new llvm::GlobalVariable(ATy, false,
432 llvm::GlobalValue::AppendingLinkage,
433 llvm::ConstantArray::get(ATy, UsedArray),
434 "llvm.used", &getModule());
435
436 GV->setSection("llvm.metadata");
437}
438
439void CodeGenModule::EmitDeferred() {
440 // Emit code for any potentially referenced deferred decls. Since a
441 // previously unused static decl may become used during the generation of code
442 // for a static function, iterate until no changes are made.
443 while (!DeferredDeclsToEmit.empty()) {
444 GlobalDecl D = DeferredDeclsToEmit.back();
445 DeferredDeclsToEmit.pop_back();
446
447 // The mangled name for the decl must have been emitted in GlobalDeclMap.
448 // Look it up to see if it was defined with a stronger definition (e.g. an
449 // extern inline function with a strong function redefinition). If so,
450 // just ignore the deferred decl.
451 llvm::GlobalValue *CGRef = GlobalDeclMap[getMangledName(D)];
452 assert(CGRef && "Deferred decl wasn't referenced?");
453
454 if (!CGRef->isDeclaration())
455 continue;
456
457 // Otherwise, emit the definition and move on to the next one.
458 EmitGlobalDefinition(D);
459 }
460}
461
462/// EmitAnnotateAttr - Generate the llvm::ConstantStruct which contains the
463/// annotation information for a given GlobalValue. The annotation struct is
464/// {i8 *, i8 *, i8 *, i32}. The first field is a constant expression, the
465/// GlobalValue being annotated. The second field is the constant string
466/// created from the AnnotateAttr's annotation. The third field is a constant
467/// string containing the name of the translation unit. The fourth field is
468/// the line number in the file of the annotated value declaration.
469///
470/// FIXME: this does not unique the annotation string constants, as llvm-gcc
471/// appears to.
472///
473llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV,
474 const AnnotateAttr *AA,
475 unsigned LineNo) {
476 llvm::Module *M = &getModule();
477
478 // get [N x i8] constants for the annotation string, and the filename string
479 // which are the 2nd and 3rd elements of the global annotation structure.
480 const llvm::Type *SBP = llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
481 llvm::Constant *anno = llvm::ConstantArray::get(AA->getAnnotation(), true);
482 llvm::Constant *unit = llvm::ConstantArray::get(M->getModuleIdentifier(),
483 true);
484
485 // Get the two global values corresponding to the ConstantArrays we just
486 // created to hold the bytes of the strings.
487 const char *StringPrefix = getContext().Target.getStringSymbolPrefix(true);
488 llvm::GlobalValue *annoGV =
489 new llvm::GlobalVariable(anno->getType(), false,
490 llvm::GlobalValue::InternalLinkage, anno,
491 GV->getName() + StringPrefix, M);
492 // translation unit name string, emitted into the llvm.metadata section.
493 llvm::GlobalValue *unitGV =
494 new llvm::GlobalVariable(unit->getType(), false,
495 llvm::GlobalValue::InternalLinkage, unit,
496 StringPrefix, M);
497
498 // Create the ConstantStruct for the global annotation.
499 llvm::Constant *Fields[4] = {
500 llvm::ConstantExpr::getBitCast(GV, SBP),
501 llvm::ConstantExpr::getBitCast(annoGV, SBP),
502 llvm::ConstantExpr::getBitCast(unitGV, SBP),
503 llvm::ConstantInt::get(llvm::Type::Int32Ty, LineNo)
504 };
505 return llvm::ConstantStruct::get(Fields, 4, false);
506}
507
508bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) {
509 // Never defer when EmitAllDecls is specified or the decl has
510 // attribute used.
511 if (Features.EmitAllDecls || Global->hasAttr<UsedAttr>(getContext()))
512 return false;
513
514 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) {
515 // Constructors and destructors should never be deferred.
516 if (FD->hasAttr<ConstructorAttr>(getContext()) ||
517 FD->hasAttr<DestructorAttr>(getContext()))
518 return false;
519
520 GVALinkage Linkage = GetLinkageForFunction(getContext(), FD, Features);
521
522 // static, static inline, always_inline, and extern inline functions can
523 // always be deferred. Normal inline functions can be deferred in C99/C++.
524 if (Linkage == GVA_Internal || Linkage == GVA_C99Inline ||
525 Linkage == GVA_CXXInline)
526 return true;
527 return false;
528 }
529
530 const VarDecl *VD = cast<VarDecl>(Global);
531 assert(VD->isFileVarDecl() && "Invalid decl");
532
533 return VD->getStorageClass() == VarDecl::Static;
534}
535
536void CodeGenModule::EmitGlobal(GlobalDecl GD) {
537 const ValueDecl *Global = GD.getDecl();
538
539 // If this is an alias definition (which otherwise looks like a declaration)
540 // emit it now.
541 if (Global->hasAttr<AliasAttr>(getContext()))
542 return EmitAliasDefinition(Global);
543
544 // Ignore declarations, they will be emitted on their first use.
545 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) {
546 // Forward declarations are emitted lazily on first use.
547 if (!FD->isThisDeclarationADefinition())
548 return;
549 } else {
550 const VarDecl *VD = cast<VarDecl>(Global);
551 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global.");
552
553 // In C++, if this is marked "extern", defer code generation.
554 if (getLangOptions().CPlusPlus && !VD->getInit() &&
555 (VD->getStorageClass() == VarDecl::Extern ||
556 VD->isExternC(getContext())))
557 return;
558
559 // In C, if this isn't a definition, defer code generation.
560 if (!getLangOptions().CPlusPlus && !VD->getInit())
561 return;
562 }
563
564 // Defer code generation when possible if this is a static definition, inline
565 // function etc. These we only want to emit if they are used.
566 if (MayDeferGeneration(Global)) {
567 // If the value has already been used, add it directly to the
568 // DeferredDeclsToEmit list.
569 const char *MangledName = getMangledName(GD);
570 if (GlobalDeclMap.count(MangledName))
571 DeferredDeclsToEmit.push_back(GD);
572 else {
573 // Otherwise, remember that we saw a deferred decl with this name. The
574 // first use of the mangled name will cause it to move into
575 // DeferredDeclsToEmit.
576 DeferredDecls[MangledName] = GD;
577 }
578 return;
579 }
580
581 // Otherwise emit the definition.
582 EmitGlobalDefinition(GD);
583}
584
585void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) {
586 const ValueDecl *D = GD.getDecl();
587
588 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D))
589 EmitCXXConstructor(CD, GD.getCtorType());
590 else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(D))
591 EmitCXXDestructor(DD, GD.getDtorType());
592 else if (isa<FunctionDecl>(D))
593 EmitGlobalFunctionDefinition(GD);
594 else if (const VarDecl *VD = dyn_cast<VarDecl>(D))
595 EmitGlobalVarDefinition(VD);
596 else {
597 assert(0 && "Invalid argument to EmitGlobalDefinition()");
598 }
599}
600
601/// GetOrCreateLLVMFunction - If the specified mangled name is not in the
602/// module, create and return an llvm Function with the specified type. If there
603/// is something in the module with the specified name, return it potentially
604/// bitcasted to the right type.
605///
606/// If D is non-null, it specifies a decl that correspond to this. This is used
607/// to set the attributes on the function when it is first created.
608llvm::Constant *CodeGenModule::GetOrCreateLLVMFunction(const char *MangledName,
609 const llvm::Type *Ty,
610 GlobalDecl D) {
611 // Lookup the entry, lazily creating it if necessary.
612 llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName];
613 if (Entry) {
614 if (Entry->getType()->getElementType() == Ty)
615 return Entry;
616
617 // Make sure the result is of the correct type.
618 const llvm::Type *PTy = llvm::PointerType::getUnqual(Ty);
619 return llvm::ConstantExpr::getBitCast(Entry, PTy);
620 }
621
622 // This is the first use or definition of a mangled name. If there is a
623 // deferred decl with this name, remember that we need to emit it at the end
624 // of the file.
625 llvm::DenseMap<const char*, GlobalDecl>::iterator DDI =
626 DeferredDecls.find(MangledName);
627 if (DDI != DeferredDecls.end()) {
628 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit
629 // list, and remove it from DeferredDecls (since we don't need it anymore).
630 DeferredDeclsToEmit.push_back(DDI->second);
631 DeferredDecls.erase(DDI);
632 } else if (const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl())) {
633 // If this the first reference to a C++ inline function in a class, queue up
634 // the deferred function body for emission. These are not seen as
635 // top-level declarations.
636 if (FD->isThisDeclarationADefinition() && MayDeferGeneration(FD))
637 DeferredDeclsToEmit.push_back(D);
638 }
639
640 // This function doesn't have a complete type (for example, the return
641 // type is an incomplete struct). Use a fake type instead, and make
642 // sure not to try to set attributes.
643 bool IsIncompleteFunction = false;
644 if (!isa<llvm::FunctionType>(Ty)) {
645 Ty = llvm::FunctionType::get(llvm::Type::VoidTy,
646 std::vector<const llvm::Type*>(), false);
647 IsIncompleteFunction = true;
648 }
649 llvm::Function *F = llvm::Function::Create(cast<llvm::FunctionType>(Ty),
650 llvm::Function::ExternalLinkage,
651 "", &getModule());
652 F->setName(MangledName);
653 if (D.getDecl())
654 SetFunctionAttributes(cast<FunctionDecl>(D.getDecl()), F,
655 IsIncompleteFunction);
656 Entry = F;
657 return F;
658}
659
660/// GetAddrOfFunction - Return the address of the given function. If Ty is
661/// non-null, then this function will use the specified type if it has to
662/// create it (this occurs when we see a definition of the function).
663llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD,
664 const llvm::Type *Ty) {
665 // If there was no specific requested type, just convert it now.
666 if (!Ty)
667 Ty = getTypes().ConvertType(GD.getDecl()->getType());
668 return GetOrCreateLLVMFunction(getMangledName(GD.getDecl()), Ty, GD);
669}
670
671/// CreateRuntimeFunction - Create a new runtime function with the specified
672/// type and name.
673llvm::Constant *
674CodeGenModule::CreateRuntimeFunction(const llvm::FunctionType *FTy,
675 const char *Name) {
676 // Convert Name to be a uniqued string from the IdentifierInfo table.
677 Name = getContext().Idents.get(Name).getName();
678 return GetOrCreateLLVMFunction(Name, FTy, GlobalDecl());
679}
680
681/// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module,
682/// create and return an llvm GlobalVariable with the specified type. If there
683/// is something in the module with the specified name, return it potentially
684/// bitcasted to the right type.
685///
686/// If D is non-null, it specifies a decl that correspond to this. This is used
687/// to set the attributes on the global when it is first created.
688llvm::Constant *CodeGenModule::GetOrCreateLLVMGlobal(const char *MangledName,
689 const llvm::PointerType*Ty,
690 const VarDecl *D) {
691 // Lookup the entry, lazily creating it if necessary.
692 llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName];
693 if (Entry) {
694 if (Entry->getType() == Ty)
695 return Entry;
696
697 // Make sure the result is of the correct type.
698 return llvm::ConstantExpr::getBitCast(Entry, Ty);
699 }
700
701 // This is the first use or definition of a mangled name. If there is a
702 // deferred decl with this name, remember that we need to emit it at the end
703 // of the file.
704 llvm::DenseMap<const char*, GlobalDecl>::iterator DDI =
705 DeferredDecls.find(MangledName);
706 if (DDI != DeferredDecls.end()) {
707 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit
708 // list, and remove it from DeferredDecls (since we don't need it anymore).
709 DeferredDeclsToEmit.push_back(DDI->second);
710 DeferredDecls.erase(DDI);
711 }
712
713 llvm::GlobalVariable *GV =
714 new llvm::GlobalVariable(Ty->getElementType(), false,
715 llvm::GlobalValue::ExternalLinkage,
716 0, "", &getModule(),
717 false, Ty->getAddressSpace());
718 GV->setName(MangledName);
719
720 // Handle things which are present even on external declarations.
721 if (D) {
722 // FIXME: This code is overly simple and should be merged with other global
723 // handling.
724 GV->setConstant(D->getType().isConstant(Context));
725
726 // FIXME: Merge with other attribute handling code.
727 if (D->getStorageClass() == VarDecl::PrivateExtern)
728 GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
729
730 if (D->hasAttr<WeakAttr>(getContext()) ||
731 D->hasAttr<WeakImportAttr>(getContext()))
732 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
733
734 GV->setThreadLocal(D->isThreadSpecified());
735 }
736
737 return Entry = GV;
738}
739
740
741/// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the
742/// given global variable. If Ty is non-null and if the global doesn't exist,
743/// then it will be greated with the specified type instead of whatever the
744/// normal requested type would be.
745llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D,
746 const llvm::Type *Ty) {
747 assert(D->hasGlobalStorage() && "Not a global variable");
748 QualType ASTTy = D->getType();
749 if (Ty == 0)
750 Ty = getTypes().ConvertTypeForMem(ASTTy);
751
752 const llvm::PointerType *PTy =
753 llvm::PointerType::get(Ty, ASTTy.getAddressSpace());
754 return GetOrCreateLLVMGlobal(getMangledName(D), PTy, D);
755}
756
757/// CreateRuntimeVariable - Create a new runtime global variable with the
758/// specified type and name.
759llvm::Constant *
760CodeGenModule::CreateRuntimeVariable(const llvm::Type *Ty,
761 const char *Name) {
762 // Convert Name to be a uniqued string from the IdentifierInfo table.
763 Name = getContext().Idents.get(Name).getName();
764 return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), 0);
765}
766
767void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) {
768 assert(!D->getInit() && "Cannot emit definite definitions here!");
769
770 if (MayDeferGeneration(D)) {
771 // If we have not seen a reference to this variable yet, place it
772 // into the deferred declarations table to be emitted if needed
773 // later.
774 const char *MangledName = getMangledName(D);
775 if (GlobalDeclMap.count(MangledName) == 0) {
776 DeferredDecls[MangledName] = GlobalDecl(D);
777 return;
778 }
779 }
780
781 // The tentative definition is the only definition.
782 EmitGlobalVarDefinition(D);
783}
784
785void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) {
786 llvm::Constant *Init = 0;
787 QualType ASTTy = D->getType();
788
789 if (D->getInit() == 0) {
790 // This is a tentative definition; tentative definitions are
791 // implicitly initialized with { 0 }.
792 //
793 // Note that tentative definitions are only emitted at the end of
794 // a translation unit, so they should never have incomplete
795 // type. In addition, EmitTentativeDefinition makes sure that we
796 // never attempt to emit a tentative definition if a real one
797 // exists. A use may still exists, however, so we still may need
798 // to do a RAUW.
799 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type");
800 Init = llvm::Constant::getNullValue(getTypes().ConvertTypeForMem(ASTTy));
801 } else {
802 Init = EmitConstantExpr(D->getInit(), D->getType());
803 if (!Init) {
804 ErrorUnsupported(D, "static initializer");
805 QualType T = D->getInit()->getType();
806 Init = llvm::UndefValue::get(getTypes().ConvertType(T));
807 }
808 }
809
810 const llvm::Type* InitType = Init->getType();
811 llvm::Constant *Entry = GetAddrOfGlobalVar(D, InitType);
812
813 // Strip off a bitcast if we got one back.
814 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) {
815 assert(CE->getOpcode() == llvm::Instruction::BitCast);
816 Entry = CE->getOperand(0);
817 }
818
819 // Entry is now either a Function or GlobalVariable.
820 llvm::GlobalVariable *GV = dyn_cast<llvm::GlobalVariable>(Entry);
821
822 // We have a definition after a declaration with the wrong type.
823 // We must make a new GlobalVariable* and update everything that used OldGV
824 // (a declaration or tentative definition) with the new GlobalVariable*
825 // (which will be a definition).
826 //
827 // This happens if there is a prototype for a global (e.g.
828 // "extern int x[];") and then a definition of a different type (e.g.
829 // "int x[10];"). This also happens when an initializer has a different type
830 // from the type of the global (this happens with unions).
831 if (GV == 0 ||
832 GV->getType()->getElementType() != InitType ||
833 GV->getType()->getAddressSpace() != ASTTy.getAddressSpace()) {
834
835 // Remove the old entry from GlobalDeclMap so that we'll create a new one.
836 GlobalDeclMap.erase(getMangledName(D));
837
838 // Make a new global with the correct type, this is now guaranteed to work.
839 GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType));
840 GV->takeName(cast<llvm::GlobalValue>(Entry));
841
842 // Replace all uses of the old global with the new global
843 llvm::Constant *NewPtrForOldDecl =
844 llvm::ConstantExpr::getBitCast(GV, Entry->getType());
845 Entry->replaceAllUsesWith(NewPtrForOldDecl);
846
847 // Erase the old global, since it is no longer used.
848 cast<llvm::GlobalValue>(Entry)->eraseFromParent();
849 }
850
851 if (const AnnotateAttr *AA = D->getAttr<AnnotateAttr>(getContext())) {
852 SourceManager &SM = Context.getSourceManager();
853 AddAnnotation(EmitAnnotateAttr(GV, AA,
854 SM.getInstantiationLineNumber(D->getLocation())));
855 }
856
857 GV->setInitializer(Init);
858 GV->setConstant(D->getType().isConstant(Context));
859 GV->setAlignment(getContext().getDeclAlignInBytes(D));
860
861 // Set the llvm linkage type as appropriate.
862 if (D->getStorageClass() == VarDecl::Static)
863 GV->setLinkage(llvm::Function::InternalLinkage);
864 else if (D->hasAttr<DLLImportAttr>(getContext()))
865 GV->setLinkage(llvm::Function::DLLImportLinkage);
866 else if (D->hasAttr<DLLExportAttr>(getContext()))
867 GV->setLinkage(llvm::Function::DLLExportLinkage);
868 else if (D->hasAttr<WeakAttr>(getContext()))
869 GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage);
870 else if (!CompileOpts.NoCommon &&
871 (!D->hasExternalStorage() && !D->getInit()))
872 GV->setLinkage(llvm::GlobalVariable::CommonLinkage);
873 else
874 GV->setLinkage(llvm::GlobalVariable::ExternalLinkage);
875
876 SetCommonAttributes(D, GV);
877
878 // Emit global variable debug information.
879 if (CGDebugInfo *DI = getDebugInfo()) {
880 DI->setLocation(D->getLocation());
881 DI->EmitGlobalVariable(GV, D);
882 }
883}
884
885/// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we
886/// implement a function with no prototype, e.g. "int foo() {}". If there are
887/// existing call uses of the old function in the module, this adjusts them to
888/// call the new function directly.
889///
890/// This is not just a cleanup: the always_inline pass requires direct calls to
891/// functions to be able to inline them. If there is a bitcast in the way, it
892/// won't inline them. Instcombine normally deletes these calls, but it isn't
893/// run at -O0.
894static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
895 llvm::Function *NewFn) {
896 // If we're redefining a global as a function, don't transform it.
897 llvm::Function *OldFn = dyn_cast<llvm::Function>(Old);
898 if (OldFn == 0) return;
899
900 const llvm::Type *NewRetTy = NewFn->getReturnType();
901 llvm::SmallVector<llvm::Value*, 4> ArgList;
902
903 for (llvm::Value::use_iterator UI = OldFn->use_begin(), E = OldFn->use_end();
904 UI != E; ) {
905 // TODO: Do invokes ever occur in C code? If so, we should handle them too.
906 unsigned OpNo = UI.getOperandNo();
907 llvm::CallInst *CI = dyn_cast<llvm::CallInst>(*UI++);
908 if (!CI || OpNo != 0) continue;
909
910 // If the return types don't match exactly, and if the call isn't dead, then
911 // we can't transform this call.
912 if (CI->getType() != NewRetTy && !CI->use_empty())
913 continue;
914
915 // If the function was passed too few arguments, don't transform. If extra
916 // arguments were passed, we silently drop them. If any of the types
917 // mismatch, we don't transform.
918 unsigned ArgNo = 0;
919 bool DontTransform = false;
920 for (llvm::Function::arg_iterator AI = NewFn->arg_begin(),
921 E = NewFn->arg_end(); AI != E; ++AI, ++ArgNo) {
922 if (CI->getNumOperands()-1 == ArgNo ||
923 CI->getOperand(ArgNo+1)->getType() != AI->getType()) {
924 DontTransform = true;
925 break;
926 }
927 }
928 if (DontTransform)
929 continue;
930
931 // Okay, we can transform this. Create the new call instruction and copy
932 // over the required information.
933 ArgList.append(CI->op_begin()+1, CI->op_begin()+1+ArgNo);
934 llvm::CallInst *NewCall = llvm::CallInst::Create(NewFn, ArgList.begin(),
935 ArgList.end(), "", CI);
936 ArgList.clear();
937 if (NewCall->getType() != llvm::Type::VoidTy)
938 NewCall->takeName(CI);
939 NewCall->setCallingConv(CI->getCallingConv());
940 NewCall->setAttributes(CI->getAttributes());
941
942 // Finally, remove the old call, replacing any uses with the new one.
943 if (!CI->use_empty())
944 CI->replaceAllUsesWith(NewCall);
945 CI->eraseFromParent();
946 }
947}
948
949
950void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) {
951 const llvm::FunctionType *Ty;
952 const FunctionDecl *D = cast<FunctionDecl>(GD.getDecl());
953
954 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) {
955 bool isVariadic = D->getType()->getAsFunctionProtoType()->isVariadic();
956
957 Ty = getTypes().GetFunctionType(getTypes().getFunctionInfo(MD), isVariadic);
958 } else {
959 Ty = cast<llvm::FunctionType>(getTypes().ConvertType(D->getType()));
960
961 // As a special case, make sure that definitions of K&R function
962 // "type foo()" aren't declared as varargs (which forces the backend
963 // to do unnecessary work).
964 if (D->getType()->isFunctionNoProtoType()) {
965 assert(Ty->isVarArg() && "Didn't lower type as expected");
966 // Due to stret, the lowered function could have arguments.
967 // Just create the same type as was lowered by ConvertType
968 // but strip off the varargs bit.
969 std::vector<const llvm::Type*> Args(Ty->param_begin(), Ty->param_end());
970 Ty = llvm::FunctionType::get(Ty->getReturnType(), Args, false);
971 }
972 }
973
974 // Get or create the prototype for the function.
975 llvm::Constant *Entry = GetAddrOfFunction(GD, Ty);
976
977 // Strip off a bitcast if we got one back.
978 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) {
979 assert(CE->getOpcode() == llvm::Instruction::BitCast);
980 Entry = CE->getOperand(0);
981 }
982
983
984 if (cast<llvm::GlobalValue>(Entry)->getType()->getElementType() != Ty) {
985 llvm::GlobalValue *OldFn = cast<llvm::GlobalValue>(Entry);
986
987 // If the types mismatch then we have to rewrite the definition.
988 assert(OldFn->isDeclaration() &&
989 "Shouldn't replace non-declaration");
990
991 // F is the Function* for the one with the wrong type, we must make a new
992 // Function* and update everything that used F (a declaration) with the new
993 // Function* (which will be a definition).
994 //
995 // This happens if there is a prototype for a function
996 // (e.g. "int f()") and then a definition of a different type
997 // (e.g. "int f(int x)"). Start by making a new function of the
998 // correct type, RAUW, then steal the name.
999 GlobalDeclMap.erase(getMangledName(D));
1000 llvm::Function *NewFn = cast<llvm::Function>(GetAddrOfFunction(GD, Ty));
1001 NewFn->takeName(OldFn);
1002
1003 // If this is an implementation of a function without a prototype, try to
1004 // replace any existing uses of the function (which may be calls) with uses
1005 // of the new function
1006 if (D->getType()->isFunctionNoProtoType()) {
1007 ReplaceUsesOfNonProtoTypeWithRealFunction(OldFn, NewFn);
1008 OldFn->removeDeadConstantUsers();
1009 }
1010
1011 // Replace uses of F with the Function we will endow with a body.
1012 if (!Entry->use_empty()) {
1013 llvm::Constant *NewPtrForOldDecl =
1014 llvm::ConstantExpr::getBitCast(NewFn, Entry->getType());
1015 Entry->replaceAllUsesWith(NewPtrForOldDecl);
1016 }
1017
1018 // Ok, delete the old function now, which is dead.
1019 OldFn->eraseFromParent();
1020
1021 Entry = NewFn;
1022 }
1023
1024 llvm::Function *Fn = cast<llvm::Function>(Entry);
1025
1026 CodeGenFunction(*this).GenerateCode(D, Fn);
1027
1028 SetFunctionDefinitionAttributes(D, Fn);
1029 SetLLVMFunctionAttributesForDefinition(D, Fn);
1030
1031 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>(getContext()))
1032 AddGlobalCtor(Fn, CA->getPriority());
1033 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>(getContext()))
1034 AddGlobalDtor(Fn, DA->getPriority());
1035}
1036
1037void CodeGenModule::EmitAliasDefinition(const ValueDecl *D) {
1038 const AliasAttr *AA = D->getAttr<AliasAttr>(getContext());
1039 assert(AA && "Not an alias?");
1040
1041 const llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
1042
1043 // Unique the name through the identifier table.
1044 const char *AliaseeName = AA->getAliasee().c_str();
1045 AliaseeName = getContext().Idents.get(AliaseeName).getName();
1046
1047 // Create a reference to the named value. This ensures that it is emitted
1048 // if a deferred decl.
1049 llvm::Constant *Aliasee;
1050 if (isa<llvm::FunctionType>(DeclTy))
1051 Aliasee = GetOrCreateLLVMFunction(AliaseeName, DeclTy, GlobalDecl());
1052 else
1053 Aliasee = GetOrCreateLLVMGlobal(AliaseeName,
1054 llvm::PointerType::getUnqual(DeclTy), 0);
1055
1056 // Create the new alias itself, but don't set a name yet.
1057 llvm::GlobalValue *GA =
1058 new llvm::GlobalAlias(Aliasee->getType(),
1059 llvm::Function::ExternalLinkage,
1060 "", Aliasee, &getModule());
1061
1062 // See if there is already something with the alias' name in the module.
1063 const char *MangledName = getMangledName(D);
1064 llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName];
1065
1066 if (Entry && !Entry->isDeclaration()) {
1067 // If there is a definition in the module, then it wins over the alias.
1068 // This is dubious, but allow it to be safe. Just ignore the alias.
1069 GA->eraseFromParent();
1070 return;
1071 }
1072
1073 if (Entry) {
1074 // If there is a declaration in the module, then we had an extern followed
1075 // by the alias, as in:
1076 // extern int test6();
1077 // ...
1078 // int test6() __attribute__((alias("test7")));
1079 //
1080 // Remove it and replace uses of it with the alias.
1081
1082 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA,
1083 Entry->getType()));
1084 Entry->eraseFromParent();
1085 }
1086
1087 // Now we know that there is no conflict, set the name.
1088 Entry = GA;
1089 GA->setName(MangledName);
1090
1091 // Set attributes which are particular to an alias; this is a
1092 // specialization of the attributes which may be set on a global
1093 // variable/function.
1094 if (D->hasAttr<DLLExportAttr>(getContext())) {
1095 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
1096 // The dllexport attribute is ignored for undefined symbols.
1097 if (FD->getBody(getContext()))
1098 GA->setLinkage(llvm::Function::DLLExportLinkage);
1099 } else {
1100 GA->setLinkage(llvm::Function::DLLExportLinkage);
1101 }
1102 } else if (D->hasAttr<WeakAttr>(getContext()) ||
1103 D->hasAttr<WeakImportAttr>(getContext())) {
1104 GA->setLinkage(llvm::Function::WeakAnyLinkage);
1105 }
1106
1107 SetCommonAttributes(D, GA);
1108}
1109
1110/// getBuiltinLibFunction - Given a builtin id for a function like
1111/// "__builtin_fabsf", return a Function* for "fabsf".
1112llvm::Value *CodeGenModule::getBuiltinLibFunction(unsigned BuiltinID) {
1113 assert((Context.BuiltinInfo.isLibFunction(BuiltinID) ||
1114 Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) &&
1115 "isn't a lib fn");
1116
1117 // Get the name, skip over the __builtin_ prefix (if necessary).
1118 const char *Name = Context.BuiltinInfo.GetName(BuiltinID);
1119 if (Context.BuiltinInfo.isLibFunction(BuiltinID))
1120 Name += 10;
1121
1122 // Get the type for the builtin.
1123 ASTContext::GetBuiltinTypeError Error;
1124 QualType Type = Context.GetBuiltinType(BuiltinID, Error);
1125 assert(Error == ASTContext::GE_None && "Can't get builtin type");
1126
1127 const llvm::FunctionType *Ty =
1128 cast<llvm::FunctionType>(getTypes().ConvertType(Type));
1129
1130 // Unique the name through the identifier table.
1131 Name = getContext().Idents.get(Name).getName();
1132 // FIXME: param attributes for sext/zext etc.
1133 return GetOrCreateLLVMFunction(Name, Ty, GlobalDecl());
1134}
1135
1136llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,const llvm::Type **Tys,
1137 unsigned NumTys) {
1138 return llvm::Intrinsic::getDeclaration(&getModule(),
1139 (llvm::Intrinsic::ID)IID, Tys, NumTys);
1140}
1141
1142llvm::Function *CodeGenModule::getMemCpyFn() {
1143 if (MemCpyFn) return MemCpyFn;
1144 const llvm::Type *IntPtr = TheTargetData.getIntPtrType();
1145 return MemCpyFn = getIntrinsic(llvm::Intrinsic::memcpy, &IntPtr, 1);
1146}
1147
1148llvm::Function *CodeGenModule::getMemMoveFn() {
1149 if (MemMoveFn) return MemMoveFn;
1150 const llvm::Type *IntPtr = TheTargetData.getIntPtrType();
1151 return MemMoveFn = getIntrinsic(llvm::Intrinsic::memmove, &IntPtr, 1);
1152}
1153
1154llvm::Function *CodeGenModule::getMemSetFn() {
1155 if (MemSetFn) return MemSetFn;
1156 const llvm::Type *IntPtr = TheTargetData.getIntPtrType();
1157 return MemSetFn = getIntrinsic(llvm::Intrinsic::memset, &IntPtr, 1);
1158}
1159
1160static void appendFieldAndPadding(CodeGenModule &CGM,
1161 std::vector<llvm::Constant*>& Fields,
1162 FieldDecl *FieldD, FieldDecl *NextFieldD,
1163 llvm::Constant* Field,
1164 RecordDecl* RD, const llvm::StructType *STy) {
1165 // Append the field.
1166 Fields.push_back(Field);
1167
1168 int StructFieldNo = CGM.getTypes().getLLVMFieldNo(FieldD);
1169
1170 int NextStructFieldNo;
1171 if (!NextFieldD) {
1172 NextStructFieldNo = STy->getNumElements();
1173 } else {
1174 NextStructFieldNo = CGM.getTypes().getLLVMFieldNo(NextFieldD);
1175 }
1176
1177 // Append padding
1178 for (int i = StructFieldNo + 1; i < NextStructFieldNo; i++) {
1179 llvm::Constant *C =
1180 llvm::Constant::getNullValue(STy->getElementType(StructFieldNo + 1));
1181
1182 Fields.push_back(C);
1183 }
1184}
1185
1186llvm::Constant *CodeGenModule::
1187GetAddrOfConstantCFString(const StringLiteral *Literal) {
1188 std::string str;
1189 unsigned StringLength = 0;
1190
1191 bool isUTF16 = false;
1192 if (Literal->containsNonAsciiOrNull()) {
1193 // Convert from UTF-8 to UTF-16.
1194 llvm::SmallVector<UTF16, 128> ToBuf(Literal->getByteLength());
1195 const UTF8 *FromPtr = (UTF8 *)Literal->getStrData();
1196 UTF16 *ToPtr = &ToBuf[0];
1197
1198 ConversionResult Result;
1199 Result = ConvertUTF8toUTF16(&FromPtr, FromPtr+Literal->getByteLength(),
1200 &ToPtr, ToPtr+Literal->getByteLength(),
1201 strictConversion);
1202 if (Result == conversionOK) {
1203 // FIXME: Storing UTF-16 in a C string is a hack to test Unicode strings
1204 // without doing more surgery to this routine. Since we aren't explicitly
1205 // checking for endianness here, it's also a bug (when generating code for
1206 // a target that doesn't match the host endianness). Modeling this as an
1207 // i16 array is likely the cleanest solution.
1208 StringLength = ToPtr-&ToBuf[0];
1209 str.assign((char *)&ToBuf[0], StringLength*2);// Twice as many UTF8 chars.
1210 isUTF16 = true;
1211 } else if (Result == sourceIllegal) {
1212 // FIXME: Have Sema::CheckObjCString() validate the UTF-8 string.
1213 str.assign(Literal->getStrData(), Literal->getByteLength());
1214 StringLength = str.length();
1215 } else
1216 assert(Result == conversionOK && "UTF-8 to UTF-16 conversion failed");
1217
1218 } else {
1219 str.assign(Literal->getStrData(), Literal->getByteLength());
1220 StringLength = str.length();
1221 }
1222 llvm::StringMapEntry<llvm::Constant *> &Entry =
1223 CFConstantStringMap.GetOrCreateValue(&str[0], &str[str.length()]);
1224
1225 if (llvm::Constant *C = Entry.getValue())
1226 return C;
1227
1228 llvm::Constant *Zero = llvm::Constant::getNullValue(llvm::Type::Int32Ty);
1229 llvm::Constant *Zeros[] = { Zero, Zero };
1230
1231 if (!CFConstantStringClassRef) {
1232 const llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy);
1233 Ty = llvm::ArrayType::get(Ty, 0);
1234
1235 // FIXME: This is fairly broken if __CFConstantStringClassReference is
1236 // already defined, in that it will get renamed and the user will most
1237 // likely see an opaque error message. This is a general issue with relying
1238 // on particular names.
1239 llvm::GlobalVariable *GV =
1240 new llvm::GlobalVariable(Ty, false,
1241 llvm::GlobalVariable::ExternalLinkage, 0,
1242 "__CFConstantStringClassReference",
1243 &getModule());
1244
1245 // Decay array -> ptr
1246 CFConstantStringClassRef =
1247 llvm::ConstantExpr::getGetElementPtr(GV, Zeros, 2);
1248 }
1249
1250 QualType CFTy = getContext().getCFConstantStringType();
1251 RecordDecl *CFRD = CFTy->getAsRecordType()->getDecl();
1252
1253 const llvm::StructType *STy =
1254 cast<llvm::StructType>(getTypes().ConvertType(CFTy));
1255
1256 std::vector<llvm::Constant*> Fields;
1257 RecordDecl::field_iterator Field = CFRD->field_begin(getContext());
1258
1259 // Class pointer.
1260 FieldDecl *CurField = *Field++;
1261 FieldDecl *NextField = *Field++;
1262 appendFieldAndPadding(*this, Fields, CurField, NextField,
1263 CFConstantStringClassRef, CFRD, STy);
1264
1265 // Flags.
1266 CurField = NextField;
1267 NextField = *Field++;
1268 const llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy);
1269 appendFieldAndPadding(*this, Fields, CurField, NextField,
1270 isUTF16 ? llvm::ConstantInt::get(Ty, 0x07d0)
1271 : llvm::ConstantInt::get(Ty, 0x07C8),
1272 CFRD, STy);
1273
1274 // String pointer.
1275 CurField = NextField;
1276 NextField = *Field++;
1277 llvm::Constant *C = llvm::ConstantArray::get(str);
1278
1279 const char *Sect, *Prefix;
1280 bool isConstant;
1281 if (isUTF16) {
1282 Prefix = getContext().Target.getUnicodeStringSymbolPrefix();
1283 Sect = getContext().Target.getUnicodeStringSection();
1284 // FIXME: Why does GCC not set constant here?
1285 isConstant = false;
1286 } else {
1287 Prefix = getContext().Target.getStringSymbolPrefix(true);
1288 Sect = getContext().Target.getCFStringDataSection();
1289 // FIXME: -fwritable-strings should probably affect this, but we
1290 // are following gcc here.
1291 isConstant = true;
1292 }
1293 llvm::GlobalVariable *GV =
1294 new llvm::GlobalVariable(C->getType(), isConstant,
1295 llvm::GlobalValue::InternalLinkage,
1296 C, Prefix, &getModule());
1297 if (Sect)
1298 GV->setSection(Sect);
1299 if (isUTF16) {
1300 unsigned Align = getContext().getTypeAlign(getContext().ShortTy)/8;
1301 GV->setAlignment(Align);
1302 }
1303 appendFieldAndPadding(*this, Fields, CurField, NextField,
1304 llvm::ConstantExpr::getGetElementPtr(GV, Zeros, 2),
1305 CFRD, STy);
1306
1307 // String length.
1308 CurField = NextField;
1309 NextField = 0;
1310 Ty = getTypes().ConvertType(getContext().LongTy);
1311 appendFieldAndPadding(*this, Fields, CurField, NextField,
1312 llvm::ConstantInt::get(Ty, StringLength), CFRD, STy);
1313
1314 // The struct.
1315 C = llvm::ConstantStruct::get(STy, Fields);
1316 GV = new llvm::GlobalVariable(C->getType(), true,
1317 llvm::GlobalVariable::InternalLinkage, C,
1318 getContext().Target.getCFStringSymbolPrefix(),
1319 &getModule());
1320 if (const char *Sect = getContext().Target.getCFStringSection())
1321 GV->setSection(Sect);
1322 Entry.setValue(GV);
1323
1324 return GV;
1325}
1326
1327/// GetStringForStringLiteral - Return the appropriate bytes for a
1328/// string literal, properly padded to match the literal type.
1329std::string CodeGenModule::GetStringForStringLiteral(const StringLiteral *E) {
1330 const char *StrData = E->getStrData();
1331 unsigned Len = E->getByteLength();
1332
1333 const ConstantArrayType *CAT =
1334 getContext().getAsConstantArrayType(E->getType());
1335 assert(CAT && "String isn't pointer or array!");
1336
1337 // Resize the string to the right size.
1338 std::string Str(StrData, StrData+Len);
1339 uint64_t RealLen = CAT->getSize().getZExtValue();
1340
1341 if (E->isWide())
1342 RealLen *= getContext().Target.getWCharWidth()/8;
1343
1344 Str.resize(RealLen, '\0');
1345
1346 return Str;
1347}
1348
1349/// GetAddrOfConstantStringFromLiteral - Return a pointer to a
1350/// constant array for the given string literal.
1351llvm::Constant *
1352CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) {
1353 // FIXME: This can be more efficient.
1354 return GetAddrOfConstantString(GetStringForStringLiteral(S));
1355}
1356
1357/// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant
1358/// array for the given ObjCEncodeExpr node.
1359llvm::Constant *
1360CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) {
1361 std::string Str;
1362 getContext().getObjCEncodingForType(E->getEncodedType(), Str);
1363
1364 return GetAddrOfConstantCString(Str);
1365}
1366
1367
1368/// GenerateWritableString -- Creates storage for a string literal.
1369static llvm::Constant *GenerateStringLiteral(const std::string &str,
1370 bool constant,
1371 CodeGenModule &CGM,
1372 const char *GlobalName) {
1373 // Create Constant for this string literal. Don't add a '\0'.
1374 llvm::Constant *C = llvm::ConstantArray::get(str, false);
1375
1376 // Create a global variable for this string
1377 return new llvm::GlobalVariable(C->getType(), constant,
1378 llvm::GlobalValue::InternalLinkage,
1379 C, GlobalName, &CGM.getModule());
1380}
1381
1382/// GetAddrOfConstantString - Returns a pointer to a character array
1383/// containing the literal. This contents are exactly that of the
1384/// given string, i.e. it will not be null terminated automatically;
1385/// see GetAddrOfConstantCString. Note that whether the result is
1386/// actually a pointer to an LLVM constant depends on
1387/// Feature.WriteableStrings.
1388///
1389/// The result has pointer to array type.
1390llvm::Constant *CodeGenModule::GetAddrOfConstantString(const std::string &str,
1391 const char *GlobalName) {
1392 bool IsConstant = !Features.WritableStrings;
1393
1394 // Get the default prefix if a name wasn't specified.
1395 if (!GlobalName)
1396 GlobalName = getContext().Target.getStringSymbolPrefix(IsConstant);
1397
1398 // Don't share any string literals if strings aren't constant.
1399 if (!IsConstant)
1400 return GenerateStringLiteral(str, false, *this, GlobalName);
1401
1402 llvm::StringMapEntry<llvm::Constant *> &Entry =
1403 ConstantStringMap.GetOrCreateValue(&str[0], &str[str.length()]);
1404
1405 if (Entry.getValue())
1406 return Entry.getValue();
1407
1408 // Create a global variable for this.
1409 llvm::Constant *C = GenerateStringLiteral(str, true, *this, GlobalName);
1410 Entry.setValue(C);
1411 return C;
1412}
1413
1414/// GetAddrOfConstantCString - Returns a pointer to a character
1415/// array containing the literal and a terminating '\-'
1416/// character. The result has pointer to array type.
1417llvm::Constant *CodeGenModule::GetAddrOfConstantCString(const std::string &str,
1418 const char *GlobalName){
1419 return GetAddrOfConstantString(str + '\0', GlobalName);
1420}
1421
1422/// EmitObjCPropertyImplementations - Emit information for synthesized
1423/// properties for an implementation.
1424void CodeGenModule::EmitObjCPropertyImplementations(const
1425 ObjCImplementationDecl *D) {
1426 for (ObjCImplementationDecl::propimpl_iterator
1427 i = D->propimpl_begin(getContext()),
1428 e = D->propimpl_end(getContext()); i != e; ++i) {
1429 ObjCPropertyImplDecl *PID = *i;
1430
1431 // Dynamic is just for type-checking.
1432 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) {
1433 ObjCPropertyDecl *PD = PID->getPropertyDecl();
1434
1435 // Determine which methods need to be implemented, some may have
1436 // been overridden. Note that ::isSynthesized is not the method
1437 // we want, that just indicates if the decl came from a
1438 // property. What we want to know is if the method is defined in
1439 // this implementation.
1440 if (!D->getInstanceMethod(getContext(), PD->getGetterName()))
1441 CodeGenFunction(*this).GenerateObjCGetter(
1442 const_cast<ObjCImplementationDecl *>(D), PID);
1443 if (!PD->isReadOnly() &&
1444 !D->getInstanceMethod(getContext(), PD->getSetterName()))
1445 CodeGenFunction(*this).GenerateObjCSetter(
1446 const_cast<ObjCImplementationDecl *>(D), PID);
1447 }
1448 }
1449}
1450
1451/// EmitNamespace - Emit all declarations in a namespace.
1452void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) {
1453 for (RecordDecl::decl_iterator I = ND->decls_begin(getContext()),
1454 E = ND->decls_end(getContext());
1455 I != E; ++I)
1456 EmitTopLevelDecl(*I);
1457}
1458
1459// EmitLinkageSpec - Emit all declarations in a linkage spec.
1460void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) {
1461 if (LSD->getLanguage() != LinkageSpecDecl::lang_c) {
1462 ErrorUnsupported(LSD, "linkage spec");
1463 return;
1464 }
1465
1466 for (RecordDecl::decl_iterator I = LSD->decls_begin(getContext()),
1467 E = LSD->decls_end(getContext());
1468 I != E; ++I)
1469 EmitTopLevelDecl(*I);
1470}
1471
1472/// EmitTopLevelDecl - Emit code for a single top level declaration.
1473void CodeGenModule::EmitTopLevelDecl(Decl *D) {
1474 // If an error has occurred, stop code generation, but continue
1475 // parsing and semantic analysis (to ensure all warnings and errors
1476 // are emitted).
1477 if (Diags.hasErrorOccurred())
1478 return;
1479
1480 switch (D->getKind()) {
1481 case Decl::CXXMethod:
1482 case Decl::Function:
1483 case Decl::Var:
1484 EmitGlobal(GlobalDecl(cast<ValueDecl>(D)));
1485 break;
1486
1487 // C++ Decls
1488 case Decl::Namespace:
1489 EmitNamespace(cast<NamespaceDecl>(D));
1490 break;
1491 // No code generation needed.
1492 case Decl::Using:
1493 break;
1494 case Decl::CXXConstructor:
1495 EmitCXXConstructors(cast<CXXConstructorDecl>(D));
1496 break;
1497 case Decl::CXXDestructor:
1498 EmitCXXDestructors(cast<CXXDestructorDecl>(D));
1499 break;
1500
1501 case Decl::StaticAssert:
1502 // Nothing to do.
1503 break;
1504
1505 // Objective-C Decls
1506
1507 // Forward declarations, no (immediate) code generation.
1508 case Decl::ObjCClass:
1509 case Decl::ObjCForwardProtocol:
1510 case Decl::ObjCCategory:
1511 case Decl::ObjCInterface:
1512 break;
1513
1514 case Decl::ObjCProtocol:
1515 Runtime->GenerateProtocol(cast<ObjCProtocolDecl>(D));
1516 break;
1517
1518 case Decl::ObjCCategoryImpl:
1519 // Categories have properties but don't support synthesize so we
1520 // can ignore them here.
1521 Runtime->GenerateCategory(cast<ObjCCategoryImplDecl>(D));
1522 break;
1523
1524 case Decl::ObjCImplementation: {
1525 ObjCImplementationDecl *OMD = cast<ObjCImplementationDecl>(D);
1526 EmitObjCPropertyImplementations(OMD);
1527 Runtime->GenerateClass(OMD);
1528 break;
1529 }
1530 case Decl::ObjCMethod: {
1531 ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(D);
1532 // If this is not a prototype, emit the body.
1533 if (OMD->getBody(getContext()))
1534 CodeGenFunction(*this).GenerateObjCMethod(OMD);
1535 break;
1536 }
1537 case Decl::ObjCCompatibleAlias:
1538 // compatibility-alias is a directive and has no code gen.
1539 break;
1540
1541 case Decl::LinkageSpec:
1542 EmitLinkageSpec(cast<LinkageSpecDecl>(D));
1543 break;
1544
1545 case Decl::FileScopeAsm: {
1546 FileScopeAsmDecl *AD = cast<FileScopeAsmDecl>(D);
1547 std::string AsmString(AD->getAsmString()->getStrData(),
1548 AD->getAsmString()->getByteLength());
1549
1550 const std::string &S = getModule().getModuleInlineAsm();
1551 if (S.empty())
1552 getModule().setModuleInlineAsm(AsmString);
1553 else
1554 getModule().setModuleInlineAsm(S + '\n' + AsmString);
1555 break;
1556 }
1557
1558 default:
1559 // Make sure we handled everything we should, every other kind is a
1560 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind
1561 // function. Need to recode Decl::Kind to do that easily.
1562 assert(isa<TypeDecl>(D) && "Unsupported decl kind");
1563 }
1564}