1 //===-- LTOModule.cpp - LLVM Link Time Optimizer --------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the Link Time Optimization library. This library is
11 // intended to be used by linker to optimize code at link time.
13 //===----------------------------------------------------------------------===//
15 #include "LTOModule.h"
16 #include "llvm/ADT/OwningPtr.h"
17 #include "llvm/ADT/Triple.h"
18 #include "llvm/Bitcode/ReaderWriter.h"
19 #include "llvm/IR/Constants.h"
20 #include "llvm/IR/LLVMContext.h"
21 #include "llvm/IR/Module.h"
22 #include "llvm/MC/MCExpr.h"
23 #include "llvm/MC/MCInst.h"
24 #include "llvm/MC/MCParser/MCAsmParser.h"
25 #include "llvm/MC/MCStreamer.h"
26 #include "llvm/MC/MCSubtargetInfo.h"
27 #include "llvm/MC/MCSymbol.h"
28 #include "llvm/MC/MCTargetAsmParser.h"
29 #include "llvm/MC/SubtargetFeature.h"
30 #include "llvm/Support/CommandLine.h"
31 #include "llvm/Support/Host.h"
32 #include "llvm/Support/FileSystem.h"
33 #include "llvm/Support/MemoryBuffer.h"
34 #include "llvm/Support/Path.h"
35 #include "llvm/Support/SourceMgr.h"
36 #include "llvm/Support/TargetRegistry.h"
37 #include "llvm/Support/TargetSelect.h"
38 #include "llvm/Support/system_error.h"
39 #include "llvm/Target/TargetRegisterInfo.h"
43 EnableFPMAD("enable-fp-mad",
44 cl::desc("Enable less precise MAD instructions to be generated"),
48 DisableFPElim("disable-fp-elim",
49 cl::desc("Disable frame pointer elimination optimization"),
53 DisableFPElimNonLeaf("disable-non-leaf-fp-elim",
54 cl::desc("Disable frame pointer elimination optimization for non-leaf funcs"),
58 EnableUnsafeFPMath("enable-unsafe-fp-math",
59 cl::desc("Enable optimizations that may decrease FP precision"),
63 EnableNoInfsFPMath("enable-no-infs-fp-math",
64 cl::desc("Enable FP math optimizations that assume no +-Infs"),
68 EnableNoNaNsFPMath("enable-no-nans-fp-math",
69 cl::desc("Enable FP math optimizations that assume no NaNs"),
73 EnableHonorSignDependentRoundingFPMath("enable-sign-dependent-rounding-fp-math",
75 cl::desc("Force codegen to assume rounding mode can change dynamically"),
79 GenerateSoftFloatCalls("soft-float",
80 cl::desc("Generate software floating point library calls"),
83 static cl::opt<llvm::FloatABI::ABIType>
84 FloatABIForCalls("float-abi",
85 cl::desc("Choose float ABI type"),
86 cl::init(FloatABI::Default),
88 clEnumValN(FloatABI::Default, "default",
89 "Target default float ABI type"),
90 clEnumValN(FloatABI::Soft, "soft",
91 "Soft float ABI (implied by -soft-float)"),
92 clEnumValN(FloatABI::Hard, "hard",
93 "Hard float ABI (uses FP registers)"),
96 static cl::opt<llvm::FPOpFusion::FPOpFusionMode>
97 FuseFPOps("fp-contract",
98 cl::desc("Enable aggresive formation of fused FP ops"),
99 cl::init(FPOpFusion::Standard),
101 clEnumValN(FPOpFusion::Fast, "fast",
102 "Fuse FP ops whenever profitable"),
103 clEnumValN(FPOpFusion::Standard, "on",
104 "Only fuse 'blessed' FP ops."),
105 clEnumValN(FPOpFusion::Strict, "off",
106 "Only fuse FP ops when the result won't be effected."),
110 DontPlaceZerosInBSS("nozero-initialized-in-bss",
111 cl::desc("Don't place zero-initialized symbols into bss section"),
115 EnableGuaranteedTailCallOpt("tailcallopt",
116 cl::desc("Turn fastcc calls into tail calls by (potentially) changing ABI."),
120 DisableTailCalls("disable-tail-calls",
121 cl::desc("Never emit tail calls"),
124 static cl::opt<unsigned>
125 OverrideStackAlignment("stack-alignment",
126 cl::desc("Override default stack alignment"),
130 EnableRealignStack("realign-stack",
131 cl::desc("Realign stack if needed"),
134 static cl::opt<std::string>
135 TrapFuncName("trap-func", cl::Hidden,
136 cl::desc("Emit a call to trap function rather than a trap instruction"),
140 EnablePIE("enable-pie",
141 cl::desc("Assume the creation of a position independent executable."),
145 SegmentedStacks("segmented-stacks",
146 cl::desc("Use segmented stacks if possible."),
150 UseInitArray("use-init-array",
151 cl::desc("Use .init_array instead of .ctors."),
154 static cl::opt<unsigned>
155 SSPBufferSize("stack-protector-buffer-size", cl::init(8),
156 cl::desc("Lower bound for a buffer to be considered for "
157 "stack protection"));
159 LTOModule::LTOModule(llvm::Module *m, llvm::TargetMachine *t)
160 : _module(m), _target(t),
161 _context(_target->getMCAsmInfo(), _target->getRegisterInfo(), NULL),
162 _mangler(_context, t) {}
164 /// isBitcodeFile - Returns 'true' if the file (or memory contents) is LLVM
166 bool LTOModule::isBitcodeFile(const void *mem, size_t length) {
167 return sys::fs::identify_magic(StringRef((const char *)mem, length)) ==
168 sys::fs::file_magic::bitcode;
171 bool LTOModule::isBitcodeFile(const char *path) {
172 sys::fs::file_magic type;
173 if (sys::fs::identify_magic(path, type))
175 return type == sys::fs::file_magic::bitcode;
178 /// isBitcodeFileForTarget - Returns 'true' if the file (or memory contents) is
179 /// LLVM bitcode for the specified triple.
180 bool LTOModule::isBitcodeFileForTarget(const void *mem, size_t length,
181 const char *triplePrefix) {
182 MemoryBuffer *buffer = makeBuffer(mem, length);
185 return isTargetMatch(buffer, triplePrefix);
188 bool LTOModule::isBitcodeFileForTarget(const char *path,
189 const char *triplePrefix) {
190 OwningPtr<MemoryBuffer> buffer;
191 if (MemoryBuffer::getFile(path, buffer))
193 return isTargetMatch(buffer.take(), triplePrefix);
196 /// isTargetMatch - Returns 'true' if the memory buffer is for the specified
198 bool LTOModule::isTargetMatch(MemoryBuffer *buffer, const char *triplePrefix) {
199 std::string Triple = getBitcodeTargetTriple(buffer, getGlobalContext());
201 return strncmp(Triple.c_str(), triplePrefix, strlen(triplePrefix)) == 0;
204 /// makeLTOModule - Create an LTOModule. N.B. These methods take ownership of
206 LTOModule *LTOModule::makeLTOModule(const char *path, std::string &errMsg) {
207 OwningPtr<MemoryBuffer> buffer;
208 if (error_code ec = MemoryBuffer::getFile(path, buffer)) {
209 errMsg = ec.message();
212 return makeLTOModule(buffer.take(), errMsg);
215 LTOModule *LTOModule::makeLTOModule(int fd, const char *path,
216 size_t size, std::string &errMsg) {
217 return makeLTOModule(fd, path, size, size, 0, errMsg);
220 LTOModule *LTOModule::makeLTOModule(int fd, const char *path,
224 std::string &errMsg) {
225 OwningPtr<MemoryBuffer> buffer;
226 if (error_code ec = MemoryBuffer::getOpenFile(fd, path, buffer, file_size,
227 map_size, offset, false)) {
228 errMsg = ec.message();
231 return makeLTOModule(buffer.take(), errMsg);
234 LTOModule *LTOModule::makeLTOModule(const void *mem, size_t length,
235 std::string &errMsg) {
236 OwningPtr<MemoryBuffer> buffer(makeBuffer(mem, length));
239 return makeLTOModule(buffer.take(), errMsg);
242 void LTOModule::getTargetOptions(TargetOptions &Options) {
243 Options.LessPreciseFPMADOption = EnableFPMAD;
244 Options.NoFramePointerElim = DisableFPElim;
245 Options.NoFramePointerElimNonLeaf = DisableFPElimNonLeaf;
246 Options.AllowFPOpFusion = FuseFPOps;
247 Options.UnsafeFPMath = EnableUnsafeFPMath;
248 Options.NoInfsFPMath = EnableNoInfsFPMath;
249 Options.NoNaNsFPMath = EnableNoNaNsFPMath;
250 Options.HonorSignDependentRoundingFPMathOption =
251 EnableHonorSignDependentRoundingFPMath;
252 Options.UseSoftFloat = GenerateSoftFloatCalls;
253 if (FloatABIForCalls != FloatABI::Default)
254 Options.FloatABIType = FloatABIForCalls;
255 Options.NoZerosInBSS = DontPlaceZerosInBSS;
256 Options.GuaranteedTailCallOpt = EnableGuaranteedTailCallOpt;
257 Options.DisableTailCalls = DisableTailCalls;
258 Options.StackAlignmentOverride = OverrideStackAlignment;
259 Options.RealignStack = EnableRealignStack;
260 Options.TrapFuncName = TrapFuncName;
261 Options.PositionIndependentExecutable = EnablePIE;
262 Options.EnableSegmentedStacks = SegmentedStacks;
263 Options.UseInitArray = UseInitArray;
264 Options.SSPBufferSize = SSPBufferSize;
267 LTOModule *LTOModule::makeLTOModule(MemoryBuffer *buffer,
268 std::string &errMsg) {
269 static bool Initialized = false;
271 InitializeAllTargets();
272 InitializeAllTargetMCs();
273 InitializeAllAsmParsers();
277 // parse bitcode buffer
278 OwningPtr<Module> m(getLazyBitcodeModule(buffer, getGlobalContext(),
285 std::string TripleStr = m->getTargetTriple();
286 if (TripleStr.empty())
287 TripleStr = sys::getDefaultTargetTriple();
288 llvm::Triple Triple(TripleStr);
290 // find machine architecture for this module
291 const Target *march = TargetRegistry::lookupTarget(TripleStr, errMsg);
295 // construct LTOModule, hand over ownership of module and target
296 SubtargetFeatures Features;
297 Features.getDefaultSubtargetFeatures(Triple);
298 std::string FeatureStr = Features.getString();
299 // Set a default CPU for Darwin triples.
301 if (Triple.isOSDarwin()) {
302 if (Triple.getArch() == llvm::Triple::x86_64)
304 else if (Triple.getArch() == llvm::Triple::x86)
307 TargetOptions Options;
308 getTargetOptions(Options);
309 TargetMachine *target = march->createTargetMachine(TripleStr, CPU, FeatureStr,
311 LTOModule *Ret = new LTOModule(m.take(), target);
312 if (Ret->parseSymbols(errMsg)) {
320 /// makeBuffer - Create a MemoryBuffer from a memory range.
321 MemoryBuffer *LTOModule::makeBuffer(const void *mem, size_t length) {
322 const char *startPtr = (const char*)mem;
323 return MemoryBuffer::getMemBuffer(StringRef(startPtr, length), "", false);
326 /// objcClassNameFromExpression - Get string that the data pointer points to.
328 LTOModule::objcClassNameFromExpression(const Constant *c, std::string &name) {
329 if (const ConstantExpr *ce = dyn_cast<ConstantExpr>(c)) {
330 Constant *op = ce->getOperand(0);
331 if (GlobalVariable *gvn = dyn_cast<GlobalVariable>(op)) {
332 Constant *cn = gvn->getInitializer();
333 if (ConstantDataArray *ca = dyn_cast<ConstantDataArray>(cn)) {
334 if (ca->isCString()) {
335 name = ".objc_class_name_" + ca->getAsCString().str();
344 /// addObjCClass - Parse i386/ppc ObjC class data structure.
345 void LTOModule::addObjCClass(const GlobalVariable *clgv) {
346 const ConstantStruct *c = dyn_cast<ConstantStruct>(clgv->getInitializer());
349 // second slot in __OBJC,__class is pointer to superclass name
350 std::string superclassName;
351 if (objcClassNameFromExpression(c->getOperand(1), superclassName)) {
352 NameAndAttributes info;
353 StringMap<NameAndAttributes>::value_type &entry =
354 _undefines.GetOrCreateValue(superclassName);
355 if (!entry.getValue().name) {
356 const char *symbolName = entry.getKey().data();
357 info.name = symbolName;
358 info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
359 info.isFunction = false;
361 entry.setValue(info);
365 // third slot in __OBJC,__class is pointer to class name
366 std::string className;
367 if (objcClassNameFromExpression(c->getOperand(2), className)) {
368 StringSet::value_type &entry = _defines.GetOrCreateValue(className);
371 NameAndAttributes info;
372 info.name = entry.getKey().data();
373 info.attributes = LTO_SYMBOL_PERMISSIONS_DATA |
374 LTO_SYMBOL_DEFINITION_REGULAR | LTO_SYMBOL_SCOPE_DEFAULT;
375 info.isFunction = false;
377 _symbols.push_back(info);
381 /// addObjCCategory - Parse i386/ppc ObjC category data structure.
382 void LTOModule::addObjCCategory(const GlobalVariable *clgv) {
383 const ConstantStruct *c = dyn_cast<ConstantStruct>(clgv->getInitializer());
386 // second slot in __OBJC,__category is pointer to target class name
387 std::string targetclassName;
388 if (!objcClassNameFromExpression(c->getOperand(1), targetclassName))
391 NameAndAttributes info;
392 StringMap<NameAndAttributes>::value_type &entry =
393 _undefines.GetOrCreateValue(targetclassName);
395 if (entry.getValue().name)
398 const char *symbolName = entry.getKey().data();
399 info.name = symbolName;
400 info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
401 info.isFunction = false;
403 entry.setValue(info);
406 /// addObjCClassRef - Parse i386/ppc ObjC class list data structure.
407 void LTOModule::addObjCClassRef(const GlobalVariable *clgv) {
408 std::string targetclassName;
409 if (!objcClassNameFromExpression(clgv->getInitializer(), targetclassName))
412 NameAndAttributes info;
413 StringMap<NameAndAttributes>::value_type &entry =
414 _undefines.GetOrCreateValue(targetclassName);
415 if (entry.getValue().name)
418 const char *symbolName = entry.getKey().data();
419 info.name = symbolName;
420 info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
421 info.isFunction = false;
423 entry.setValue(info);
426 /// addDefinedDataSymbol - Add a data symbol as defined to the list.
427 void LTOModule::addDefinedDataSymbol(const GlobalValue *v) {
428 // Add to list of defined symbols.
429 addDefinedSymbol(v, false);
431 if (!v->hasSection() /* || !isTargetDarwin */)
434 // Special case i386/ppc ObjC data structures in magic sections:
435 // The issue is that the old ObjC object format did some strange
436 // contortions to avoid real linker symbols. For instance, the
437 // ObjC class data structure is allocated statically in the executable
438 // that defines that class. That data structures contains a pointer to
439 // its superclass. But instead of just initializing that part of the
440 // struct to the address of its superclass, and letting the static and
441 // dynamic linkers do the rest, the runtime works by having that field
442 // instead point to a C-string that is the name of the superclass.
443 // At runtime the objc initialization updates that pointer and sets
444 // it to point to the actual super class. As far as the linker
445 // knows it is just a pointer to a string. But then someone wanted the
446 // linker to issue errors at build time if the superclass was not found.
447 // So they figured out a way in mach-o object format to use an absolute
448 // symbols (.objc_class_name_Foo = 0) and a floating reference
449 // (.reference .objc_class_name_Bar) to cause the linker into erroring when
450 // a class was missing.
451 // The following synthesizes the implicit .objc_* symbols for the linker
452 // from the ObjC data structures generated by the front end.
454 // special case if this data blob is an ObjC class definition
455 if (v->getSection().compare(0, 15, "__OBJC,__class,") == 0) {
456 if (const GlobalVariable *gv = dyn_cast<GlobalVariable>(v)) {
461 // special case if this data blob is an ObjC category definition
462 else if (v->getSection().compare(0, 18, "__OBJC,__category,") == 0) {
463 if (const GlobalVariable *gv = dyn_cast<GlobalVariable>(v)) {
468 // special case if this data blob is the list of referenced classes
469 else if (v->getSection().compare(0, 18, "__OBJC,__cls_refs,") == 0) {
470 if (const GlobalVariable *gv = dyn_cast<GlobalVariable>(v)) {
476 /// addDefinedFunctionSymbol - Add a function symbol as defined to the list.
477 void LTOModule::addDefinedFunctionSymbol(const Function *f) {
478 // add to list of defined symbols
479 addDefinedSymbol(f, true);
482 /// addDefinedSymbol - Add a defined symbol to the list.
483 void LTOModule::addDefinedSymbol(const GlobalValue *def, bool isFunction) {
484 // ignore all llvm.* symbols
485 if (def->getName().startswith("llvm."))
488 // string is owned by _defines
489 SmallString<64> Buffer;
490 _mangler.getNameWithPrefix(Buffer, def, false);
492 // set alignment part log2() can have rounding errors
493 uint32_t align = def->getAlignment();
494 uint32_t attr = align ? countTrailingZeros(def->getAlignment()) : 0;
496 // set permissions part
498 attr |= LTO_SYMBOL_PERMISSIONS_CODE;
500 const GlobalVariable *gv = dyn_cast<GlobalVariable>(def);
501 if (gv && gv->isConstant())
502 attr |= LTO_SYMBOL_PERMISSIONS_RODATA;
504 attr |= LTO_SYMBOL_PERMISSIONS_DATA;
507 // set definition part
508 if (def->hasWeakLinkage() || def->hasLinkOnceLinkage() ||
509 def->hasLinkerPrivateWeakLinkage())
510 attr |= LTO_SYMBOL_DEFINITION_WEAK;
511 else if (def->hasCommonLinkage())
512 attr |= LTO_SYMBOL_DEFINITION_TENTATIVE;
514 attr |= LTO_SYMBOL_DEFINITION_REGULAR;
517 if (def->hasHiddenVisibility())
518 attr |= LTO_SYMBOL_SCOPE_HIDDEN;
519 else if (def->hasProtectedVisibility())
520 attr |= LTO_SYMBOL_SCOPE_PROTECTED;
521 else if (def->hasExternalLinkage() || def->hasWeakLinkage() ||
522 def->hasLinkOnceLinkage() || def->hasCommonLinkage() ||
523 def->hasLinkerPrivateWeakLinkage())
524 attr |= LTO_SYMBOL_SCOPE_DEFAULT;
525 else if (def->hasLinkOnceODRAutoHideLinkage())
526 attr |= LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN;
528 attr |= LTO_SYMBOL_SCOPE_INTERNAL;
530 StringSet::value_type &entry = _defines.GetOrCreateValue(Buffer);
533 // fill information structure
534 NameAndAttributes info;
535 StringRef Name = entry.getKey();
536 info.name = Name.data();
537 assert(info.name[Name.size()] == '\0');
538 info.attributes = attr;
539 info.isFunction = isFunction;
542 // add to table of symbols
543 _symbols.push_back(info);
546 /// addAsmGlobalSymbol - Add a global symbol from module-level ASM to the
548 void LTOModule::addAsmGlobalSymbol(const char *name,
549 lto_symbol_attributes scope) {
550 StringSet::value_type &entry = _defines.GetOrCreateValue(name);
552 // only add new define if not already defined
553 if (entry.getValue())
558 NameAndAttributes &info = _undefines[entry.getKey().data()];
560 if (info.symbol == 0) {
561 // FIXME: This is trying to take care of module ASM like this:
563 // module asm ".zerofill __FOO, __foo, _bar_baz_qux, 0"
565 // but is gross and its mother dresses it funny. Have the ASM parser give us
566 // more details for this type of situation so that we're not guessing so
569 // fill information structure
570 info.name = entry.getKey().data();
572 LTO_SYMBOL_PERMISSIONS_DATA | LTO_SYMBOL_DEFINITION_REGULAR | scope;
573 info.isFunction = false;
576 // add to table of symbols
577 _symbols.push_back(info);
582 addDefinedFunctionSymbol(cast<Function>(info.symbol));
584 addDefinedDataSymbol(info.symbol);
586 _symbols.back().attributes &= ~LTO_SYMBOL_SCOPE_MASK;
587 _symbols.back().attributes |= scope;
590 /// addAsmGlobalSymbolUndef - Add a global symbol from module-level ASM to the
592 void LTOModule::addAsmGlobalSymbolUndef(const char *name) {
593 StringMap<NameAndAttributes>::value_type &entry =
594 _undefines.GetOrCreateValue(name);
596 _asm_undefines.push_back(entry.getKey().data());
598 // we already have the symbol
599 if (entry.getValue().name)
602 uint32_t attr = LTO_SYMBOL_DEFINITION_UNDEFINED;;
603 attr |= LTO_SYMBOL_SCOPE_DEFAULT;
604 NameAndAttributes info;
605 info.name = entry.getKey().data();
606 info.attributes = attr;
607 info.isFunction = false;
610 entry.setValue(info);
613 /// addPotentialUndefinedSymbol - Add a symbol which isn't defined just yet to a
614 /// list to be resolved later.
616 LTOModule::addPotentialUndefinedSymbol(const GlobalValue *decl, bool isFunc) {
617 // ignore all llvm.* symbols
618 if (decl->getName().startswith("llvm."))
621 // ignore all aliases
622 if (isa<GlobalAlias>(decl))
625 SmallString<64> name;
626 _mangler.getNameWithPrefix(name, decl, false);
628 StringMap<NameAndAttributes>::value_type &entry =
629 _undefines.GetOrCreateValue(name);
631 // we already have the symbol
632 if (entry.getValue().name)
635 NameAndAttributes info;
637 info.name = entry.getKey().data();
639 if (decl->hasExternalWeakLinkage())
640 info.attributes = LTO_SYMBOL_DEFINITION_WEAKUNDEF;
642 info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
644 info.isFunction = isFunc;
647 entry.setValue(info);
651 class RecordStreamer : public MCStreamer {
653 enum State { NeverSeen, Global, Defined, DefinedGlobal, Used };
656 StringMap<State> Symbols;
658 void markDefined(const MCSymbol &Symbol) {
659 State &S = Symbols[Symbol.getName()];
672 void markGlobal(const MCSymbol &Symbol) {
673 State &S = Symbols[Symbol.getName()];
687 void markUsed(const MCSymbol &Symbol) {
688 State &S = Symbols[Symbol.getName()];
702 // FIXME: mostly copied for the obj streamer.
703 void AddValueSymbols(const MCExpr *Value) {
704 switch (Value->getKind()) {
706 // FIXME: What should we do in here?
709 case MCExpr::Constant:
712 case MCExpr::Binary: {
713 const MCBinaryExpr *BE = cast<MCBinaryExpr>(Value);
714 AddValueSymbols(BE->getLHS());
715 AddValueSymbols(BE->getRHS());
719 case MCExpr::SymbolRef:
720 markUsed(cast<MCSymbolRefExpr>(Value)->getSymbol());
724 AddValueSymbols(cast<MCUnaryExpr>(Value)->getSubExpr());
730 typedef StringMap<State>::const_iterator const_iterator;
732 const_iterator begin() {
733 return Symbols.begin();
736 const_iterator end() {
737 return Symbols.end();
740 RecordStreamer(MCContext &Context)
741 : MCStreamer(SK_RecordStreamer, Context) {}
743 virtual void EmitInstruction(const MCInst &Inst) {
745 for (unsigned i = Inst.getNumOperands(); i--; )
746 if (Inst.getOperand(i).isExpr())
747 AddValueSymbols(Inst.getOperand(i).getExpr());
749 virtual void EmitLabel(MCSymbol *Symbol) {
750 Symbol->setSection(*getCurrentSection().first);
751 markDefined(*Symbol);
753 virtual void EmitDebugLabel(MCSymbol *Symbol) {
756 virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
757 // FIXME: should we handle aliases?
758 markDefined(*Symbol);
760 virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute) {
761 if (Attribute == MCSA_Global)
764 virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
765 uint64_t Size , unsigned ByteAlignment) {
766 markDefined(*Symbol);
768 virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
769 unsigned ByteAlignment) {
770 markDefined(*Symbol);
773 virtual void EmitBundleAlignMode(unsigned AlignPow2) {}
774 virtual void EmitBundleLock(bool AlignToEnd) {}
775 virtual void EmitBundleUnlock() {}
778 virtual void ChangeSection(const MCSection *Section,
779 const MCExpr *Subsection) {}
780 virtual void InitToTextSection() {}
781 virtual void InitSections() {}
782 virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) {}
783 virtual void EmitThumbFunc(MCSymbol *Func) {}
784 virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {}
785 virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) {}
786 virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) {}
787 virtual void EmitCOFFSymbolStorageClass(int StorageClass) {}
788 virtual void EmitCOFFSymbolType(int Type) {}
789 virtual void EndCOFFSymbolDef() {}
790 virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {}
791 virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
792 unsigned ByteAlignment) {}
793 virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
794 uint64_t Size, unsigned ByteAlignment) {}
795 virtual void EmitBytes(StringRef Data) {}
796 virtual void EmitValueImpl(const MCExpr *Value, unsigned Size) {}
797 virtual void EmitULEB128Value(const MCExpr *Value) {}
798 virtual void EmitSLEB128Value(const MCExpr *Value) {}
799 virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value,
801 unsigned MaxBytesToEmit) {}
802 virtual void EmitCodeAlignment(unsigned ByteAlignment,
803 unsigned MaxBytesToEmit) {}
804 virtual bool EmitValueToOffset(const MCExpr *Offset,
805 unsigned char Value ) { return false; }
806 virtual void EmitFileDirective(StringRef Filename) {}
807 virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta,
808 const MCSymbol *LastLabel,
809 const MCSymbol *Label,
810 unsigned PointerSize) {}
811 virtual void FinishImpl() {}
813 static bool classof(const MCStreamer *S) {
814 return S->getKind() == SK_RecordStreamer;
817 } // end anonymous namespace
819 /// addAsmGlobalSymbols - Add global symbols from module-level ASM to the
820 /// defined or undefined lists.
821 bool LTOModule::addAsmGlobalSymbols(std::string &errMsg) {
822 const std::string &inlineAsm = _module->getModuleInlineAsm();
823 if (inlineAsm.empty())
826 OwningPtr<RecordStreamer> Streamer(new RecordStreamer(_context));
827 MemoryBuffer *Buffer = MemoryBuffer::getMemBuffer(inlineAsm);
829 SrcMgr.AddNewSourceBuffer(Buffer, SMLoc());
830 OwningPtr<MCAsmParser> Parser(createMCAsmParser(SrcMgr,
832 *_target->getMCAsmInfo()));
833 const Target &T = _target->getTarget();
834 OwningPtr<MCSubtargetInfo>
835 STI(T.createMCSubtargetInfo(_target->getTargetTriple(),
836 _target->getTargetCPU(),
837 _target->getTargetFeatureString()));
838 OwningPtr<MCTargetAsmParser> TAP(T.createMCAsmParser(*STI, *Parser.get()));
840 errMsg = "target " + std::string(T.getName()) +
841 " does not define AsmParser.";
845 Parser->setTargetParser(*TAP);
846 if (Parser->Run(false))
849 for (RecordStreamer::const_iterator i = Streamer->begin(),
850 e = Streamer->end(); i != e; ++i) {
851 StringRef Key = i->first();
852 RecordStreamer::State Value = i->second;
853 if (Value == RecordStreamer::DefinedGlobal)
854 addAsmGlobalSymbol(Key.data(), LTO_SYMBOL_SCOPE_DEFAULT);
855 else if (Value == RecordStreamer::Defined)
856 addAsmGlobalSymbol(Key.data(), LTO_SYMBOL_SCOPE_INTERNAL);
857 else if (Value == RecordStreamer::Global ||
858 Value == RecordStreamer::Used)
859 addAsmGlobalSymbolUndef(Key.data());
865 /// isDeclaration - Return 'true' if the global value is a declaration.
866 static bool isDeclaration(const GlobalValue &V) {
867 if (V.hasAvailableExternallyLinkage())
870 if (V.isMaterializable())
873 return V.isDeclaration();
876 /// parseSymbols - Parse the symbols from the module and model-level ASM and add
877 /// them to either the defined or undefined lists.
878 bool LTOModule::parseSymbols(std::string &errMsg) {
880 for (Module::iterator f = _module->begin(), e = _module->end(); f != e; ++f) {
881 if (isDeclaration(*f))
882 addPotentialUndefinedSymbol(f, true);
884 addDefinedFunctionSymbol(f);
888 for (Module::global_iterator v = _module->global_begin(),
889 e = _module->global_end(); v != e; ++v) {
890 if (isDeclaration(*v))
891 addPotentialUndefinedSymbol(v, false);
893 addDefinedDataSymbol(v);
897 if (addAsmGlobalSymbols(errMsg))
901 for (Module::alias_iterator a = _module->alias_begin(),
902 e = _module->alias_end(); a != e; ++a) {
903 if (isDeclaration(*a->getAliasedGlobal()))
904 // Is an alias to a declaration.
905 addPotentialUndefinedSymbol(a, false);
907 addDefinedDataSymbol(a);
910 // make symbols for all undefines
911 for (StringMap<NameAndAttributes>::iterator u =_undefines.begin(),
912 e = _undefines.end(); u != e; ++u) {
913 // If this symbol also has a definition, then don't make an undefine because
914 // it is a tentative definition.
915 if (_defines.count(u->getKey())) continue;
916 NameAndAttributes info = u->getValue();
917 _symbols.push_back(info);