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 LTOModule::LTOModule(llvm::Module *m, llvm::TargetMachine *t)
155 : _module(m), _target(t),
156 _context(_target->getMCAsmInfo(), _target->getRegisterInfo(), NULL),
157 _mangler(_context, t) {}
159 /// isBitcodeFile - Returns 'true' if the file (or memory contents) is LLVM
161 bool LTOModule::isBitcodeFile(const void *mem, size_t length) {
162 return sys::fs::identify_magic(StringRef((const char *)mem, length)) ==
163 sys::fs::file_magic::bitcode;
166 bool LTOModule::isBitcodeFile(const char *path) {
167 sys::fs::file_magic type;
168 if (sys::fs::identify_magic(path, type))
170 return type == sys::fs::file_magic::bitcode;
173 /// isBitcodeFileForTarget - Returns 'true' if the file (or memory contents) is
174 /// LLVM bitcode for the specified triple.
175 bool LTOModule::isBitcodeFileForTarget(const void *mem, size_t length,
176 const char *triplePrefix) {
177 MemoryBuffer *buffer = makeBuffer(mem, length);
180 return isTargetMatch(buffer, triplePrefix);
183 bool LTOModule::isBitcodeFileForTarget(const char *path,
184 const char *triplePrefix) {
185 OwningPtr<MemoryBuffer> buffer;
186 if (MemoryBuffer::getFile(path, buffer))
188 return isTargetMatch(buffer.take(), triplePrefix);
191 /// isTargetMatch - Returns 'true' if the memory buffer is for the specified
193 bool LTOModule::isTargetMatch(MemoryBuffer *buffer, const char *triplePrefix) {
194 std::string Triple = getBitcodeTargetTriple(buffer, getGlobalContext());
196 return strncmp(Triple.c_str(), triplePrefix, strlen(triplePrefix)) == 0;
199 /// makeLTOModule - Create an LTOModule. N.B. These methods take ownership of
201 LTOModule *LTOModule::makeLTOModule(const char *path, std::string &errMsg) {
202 OwningPtr<MemoryBuffer> buffer;
203 if (error_code ec = MemoryBuffer::getFile(path, buffer)) {
204 errMsg = ec.message();
207 return makeLTOModule(buffer.take(), errMsg);
210 LTOModule *LTOModule::makeLTOModule(int fd, const char *path,
211 size_t size, std::string &errMsg) {
212 return makeLTOModule(fd, path, size, 0, errMsg);
215 LTOModule *LTOModule::makeLTOModule(int fd, const char *path,
218 std::string &errMsg) {
219 OwningPtr<MemoryBuffer> buffer;
221 MemoryBuffer::getOpenFileSlice(fd, path, buffer, map_size, offset)) {
222 errMsg = ec.message();
225 return makeLTOModule(buffer.take(), errMsg);
228 LTOModule *LTOModule::makeLTOModule(const void *mem, size_t length,
229 std::string &errMsg) {
230 OwningPtr<MemoryBuffer> buffer(makeBuffer(mem, length));
233 return makeLTOModule(buffer.take(), errMsg);
236 void LTOModule::getTargetOptions(TargetOptions &Options) {
237 Options.LessPreciseFPMADOption = EnableFPMAD;
238 Options.NoFramePointerElim = DisableFPElim;
239 Options.NoFramePointerElimNonLeaf = DisableFPElimNonLeaf;
240 Options.AllowFPOpFusion = FuseFPOps;
241 Options.UnsafeFPMath = EnableUnsafeFPMath;
242 Options.NoInfsFPMath = EnableNoInfsFPMath;
243 Options.NoNaNsFPMath = EnableNoNaNsFPMath;
244 Options.HonorSignDependentRoundingFPMathOption =
245 EnableHonorSignDependentRoundingFPMath;
246 Options.UseSoftFloat = GenerateSoftFloatCalls;
247 if (FloatABIForCalls != FloatABI::Default)
248 Options.FloatABIType = FloatABIForCalls;
249 Options.NoZerosInBSS = DontPlaceZerosInBSS;
250 Options.GuaranteedTailCallOpt = EnableGuaranteedTailCallOpt;
251 Options.DisableTailCalls = DisableTailCalls;
252 Options.StackAlignmentOverride = OverrideStackAlignment;
253 Options.RealignStack = EnableRealignStack;
254 Options.TrapFuncName = TrapFuncName;
255 Options.PositionIndependentExecutable = EnablePIE;
256 Options.EnableSegmentedStacks = SegmentedStacks;
257 Options.UseInitArray = UseInitArray;
260 LTOModule *LTOModule::makeLTOModule(MemoryBuffer *buffer,
261 std::string &errMsg) {
262 static bool Initialized = false;
264 InitializeAllTargets();
265 InitializeAllTargetMCs();
266 InitializeAllAsmParsers();
270 // parse bitcode buffer
271 OwningPtr<Module> m(getLazyBitcodeModule(buffer, getGlobalContext(),
278 std::string TripleStr = m->getTargetTriple();
279 if (TripleStr.empty())
280 TripleStr = sys::getDefaultTargetTriple();
281 llvm::Triple Triple(TripleStr);
283 // find machine architecture for this module
284 const Target *march = TargetRegistry::lookupTarget(TripleStr, errMsg);
288 // construct LTOModule, hand over ownership of module and target
289 SubtargetFeatures Features;
290 Features.getDefaultSubtargetFeatures(Triple);
291 std::string FeatureStr = Features.getString();
292 // Set a default CPU for Darwin triples.
294 if (Triple.isOSDarwin()) {
295 if (Triple.getArch() == llvm::Triple::x86_64)
297 else if (Triple.getArch() == llvm::Triple::x86)
300 TargetOptions Options;
301 getTargetOptions(Options);
302 TargetMachine *target = march->createTargetMachine(TripleStr, CPU, FeatureStr,
304 LTOModule *Ret = new LTOModule(m.take(), target);
305 if (Ret->parseSymbols(errMsg)) {
313 /// makeBuffer - Create a MemoryBuffer from a memory range.
314 MemoryBuffer *LTOModule::makeBuffer(const void *mem, size_t length) {
315 const char *startPtr = (const char*)mem;
316 return MemoryBuffer::getMemBuffer(StringRef(startPtr, length), "", false);
319 /// objcClassNameFromExpression - Get string that the data pointer points to.
321 LTOModule::objcClassNameFromExpression(const Constant *c, std::string &name) {
322 if (const ConstantExpr *ce = dyn_cast<ConstantExpr>(c)) {
323 Constant *op = ce->getOperand(0);
324 if (GlobalVariable *gvn = dyn_cast<GlobalVariable>(op)) {
325 Constant *cn = gvn->getInitializer();
326 if (ConstantDataArray *ca = dyn_cast<ConstantDataArray>(cn)) {
327 if (ca->isCString()) {
328 name = ".objc_class_name_" + ca->getAsCString().str();
337 /// addObjCClass - Parse i386/ppc ObjC class data structure.
338 void LTOModule::addObjCClass(const GlobalVariable *clgv) {
339 const ConstantStruct *c = dyn_cast<ConstantStruct>(clgv->getInitializer());
342 // second slot in __OBJC,__class is pointer to superclass name
343 std::string superclassName;
344 if (objcClassNameFromExpression(c->getOperand(1), superclassName)) {
345 NameAndAttributes info;
346 StringMap<NameAndAttributes>::value_type &entry =
347 _undefines.GetOrCreateValue(superclassName);
348 if (!entry.getValue().name) {
349 const char *symbolName = entry.getKey().data();
350 info.name = symbolName;
351 info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
352 info.isFunction = false;
354 entry.setValue(info);
358 // third slot in __OBJC,__class is pointer to class name
359 std::string className;
360 if (objcClassNameFromExpression(c->getOperand(2), className)) {
361 StringSet::value_type &entry = _defines.GetOrCreateValue(className);
364 NameAndAttributes info;
365 info.name = entry.getKey().data();
366 info.attributes = LTO_SYMBOL_PERMISSIONS_DATA |
367 LTO_SYMBOL_DEFINITION_REGULAR | LTO_SYMBOL_SCOPE_DEFAULT;
368 info.isFunction = false;
370 _symbols.push_back(info);
374 /// addObjCCategory - Parse i386/ppc ObjC category data structure.
375 void LTOModule::addObjCCategory(const GlobalVariable *clgv) {
376 const ConstantStruct *c = dyn_cast<ConstantStruct>(clgv->getInitializer());
379 // second slot in __OBJC,__category is pointer to target class name
380 std::string targetclassName;
381 if (!objcClassNameFromExpression(c->getOperand(1), targetclassName))
384 NameAndAttributes info;
385 StringMap<NameAndAttributes>::value_type &entry =
386 _undefines.GetOrCreateValue(targetclassName);
388 if (entry.getValue().name)
391 const char *symbolName = entry.getKey().data();
392 info.name = symbolName;
393 info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
394 info.isFunction = false;
396 entry.setValue(info);
399 /// addObjCClassRef - Parse i386/ppc ObjC class list data structure.
400 void LTOModule::addObjCClassRef(const GlobalVariable *clgv) {
401 std::string targetclassName;
402 if (!objcClassNameFromExpression(clgv->getInitializer(), targetclassName))
405 NameAndAttributes info;
406 StringMap<NameAndAttributes>::value_type &entry =
407 _undefines.GetOrCreateValue(targetclassName);
408 if (entry.getValue().name)
411 const char *symbolName = entry.getKey().data();
412 info.name = symbolName;
413 info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
414 info.isFunction = false;
416 entry.setValue(info);
419 /// addDefinedDataSymbol - Add a data symbol as defined to the list.
420 void LTOModule::addDefinedDataSymbol(const GlobalValue *v) {
421 // Add to list of defined symbols.
422 addDefinedSymbol(v, false);
424 if (!v->hasSection() /* || !isTargetDarwin */)
427 // Special case i386/ppc ObjC data structures in magic sections:
428 // The issue is that the old ObjC object format did some strange
429 // contortions to avoid real linker symbols. For instance, the
430 // ObjC class data structure is allocated statically in the executable
431 // that defines that class. That data structures contains a pointer to
432 // its superclass. But instead of just initializing that part of the
433 // struct to the address of its superclass, and letting the static and
434 // dynamic linkers do the rest, the runtime works by having that field
435 // instead point to a C-string that is the name of the superclass.
436 // At runtime the objc initialization updates that pointer and sets
437 // it to point to the actual super class. As far as the linker
438 // knows it is just a pointer to a string. But then someone wanted the
439 // linker to issue errors at build time if the superclass was not found.
440 // So they figured out a way in mach-o object format to use an absolute
441 // symbols (.objc_class_name_Foo = 0) and a floating reference
442 // (.reference .objc_class_name_Bar) to cause the linker into erroring when
443 // a class was missing.
444 // The following synthesizes the implicit .objc_* symbols for the linker
445 // from the ObjC data structures generated by the front end.
447 // special case if this data blob is an ObjC class definition
448 if (v->getSection().compare(0, 15, "__OBJC,__class,") == 0) {
449 if (const GlobalVariable *gv = dyn_cast<GlobalVariable>(v)) {
454 // special case if this data blob is an ObjC category definition
455 else if (v->getSection().compare(0, 18, "__OBJC,__category,") == 0) {
456 if (const GlobalVariable *gv = dyn_cast<GlobalVariable>(v)) {
461 // special case if this data blob is the list of referenced classes
462 else if (v->getSection().compare(0, 18, "__OBJC,__cls_refs,") == 0) {
463 if (const GlobalVariable *gv = dyn_cast<GlobalVariable>(v)) {
469 /// addDefinedFunctionSymbol - Add a function symbol as defined to the list.
470 void LTOModule::addDefinedFunctionSymbol(const Function *f) {
471 // add to list of defined symbols
472 addDefinedSymbol(f, true);
475 /// addDefinedSymbol - Add a defined symbol to the list.
476 void LTOModule::addDefinedSymbol(const GlobalValue *def, bool isFunction) {
477 // ignore all llvm.* symbols
478 if (def->getName().startswith("llvm."))
481 // string is owned by _defines
482 SmallString<64> Buffer;
483 _mangler.getNameWithPrefix(Buffer, def, false);
485 // set alignment part log2() can have rounding errors
486 uint32_t align = def->getAlignment();
487 uint32_t attr = align ? countTrailingZeros(def->getAlignment()) : 0;
489 // set permissions part
491 attr |= LTO_SYMBOL_PERMISSIONS_CODE;
493 const GlobalVariable *gv = dyn_cast<GlobalVariable>(def);
494 if (gv && gv->isConstant())
495 attr |= LTO_SYMBOL_PERMISSIONS_RODATA;
497 attr |= LTO_SYMBOL_PERMISSIONS_DATA;
500 // set definition part
501 if (def->hasWeakLinkage() || def->hasLinkOnceLinkage() ||
502 def->hasLinkerPrivateWeakLinkage())
503 attr |= LTO_SYMBOL_DEFINITION_WEAK;
504 else if (def->hasCommonLinkage())
505 attr |= LTO_SYMBOL_DEFINITION_TENTATIVE;
507 attr |= LTO_SYMBOL_DEFINITION_REGULAR;
510 if (def->hasHiddenVisibility())
511 attr |= LTO_SYMBOL_SCOPE_HIDDEN;
512 else if (def->hasProtectedVisibility())
513 attr |= LTO_SYMBOL_SCOPE_PROTECTED;
514 else if (def->hasExternalLinkage() || def->hasWeakLinkage() ||
515 def->hasLinkOnceLinkage() || def->hasCommonLinkage() ||
516 def->hasLinkerPrivateWeakLinkage())
517 attr |= LTO_SYMBOL_SCOPE_DEFAULT;
518 else if (def->hasLinkOnceODRAutoHideLinkage())
519 attr |= LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN;
521 attr |= LTO_SYMBOL_SCOPE_INTERNAL;
523 StringSet::value_type &entry = _defines.GetOrCreateValue(Buffer);
526 // fill information structure
527 NameAndAttributes info;
528 StringRef Name = entry.getKey();
529 info.name = Name.data();
530 assert(info.name[Name.size()] == '\0');
531 info.attributes = attr;
532 info.isFunction = isFunction;
535 // add to table of symbols
536 _symbols.push_back(info);
539 /// addAsmGlobalSymbol - Add a global symbol from module-level ASM to the
541 void LTOModule::addAsmGlobalSymbol(const char *name,
542 lto_symbol_attributes scope) {
543 StringSet::value_type &entry = _defines.GetOrCreateValue(name);
545 // only add new define if not already defined
546 if (entry.getValue())
551 NameAndAttributes &info = _undefines[entry.getKey().data()];
553 if (info.symbol == 0) {
554 // FIXME: This is trying to take care of module ASM like this:
556 // module asm ".zerofill __FOO, __foo, _bar_baz_qux, 0"
558 // but is gross and its mother dresses it funny. Have the ASM parser give us
559 // more details for this type of situation so that we're not guessing so
562 // fill information structure
563 info.name = entry.getKey().data();
565 LTO_SYMBOL_PERMISSIONS_DATA | LTO_SYMBOL_DEFINITION_REGULAR | scope;
566 info.isFunction = false;
569 // add to table of symbols
570 _symbols.push_back(info);
575 addDefinedFunctionSymbol(cast<Function>(info.symbol));
577 addDefinedDataSymbol(info.symbol);
579 _symbols.back().attributes &= ~LTO_SYMBOL_SCOPE_MASK;
580 _symbols.back().attributes |= scope;
583 /// addAsmGlobalSymbolUndef - Add a global symbol from module-level ASM to the
585 void LTOModule::addAsmGlobalSymbolUndef(const char *name) {
586 StringMap<NameAndAttributes>::value_type &entry =
587 _undefines.GetOrCreateValue(name);
589 _asm_undefines.push_back(entry.getKey().data());
591 // we already have the symbol
592 if (entry.getValue().name)
595 uint32_t attr = LTO_SYMBOL_DEFINITION_UNDEFINED;;
596 attr |= LTO_SYMBOL_SCOPE_DEFAULT;
597 NameAndAttributes info;
598 info.name = entry.getKey().data();
599 info.attributes = attr;
600 info.isFunction = false;
603 entry.setValue(info);
606 /// addPotentialUndefinedSymbol - Add a symbol which isn't defined just yet to a
607 /// list to be resolved later.
609 LTOModule::addPotentialUndefinedSymbol(const GlobalValue *decl, bool isFunc) {
610 // ignore all llvm.* symbols
611 if (decl->getName().startswith("llvm."))
614 // ignore all aliases
615 if (isa<GlobalAlias>(decl))
618 SmallString<64> name;
619 _mangler.getNameWithPrefix(name, decl, false);
621 StringMap<NameAndAttributes>::value_type &entry =
622 _undefines.GetOrCreateValue(name);
624 // we already have the symbol
625 if (entry.getValue().name)
628 NameAndAttributes info;
630 info.name = entry.getKey().data();
632 if (decl->hasExternalWeakLinkage())
633 info.attributes = LTO_SYMBOL_DEFINITION_WEAKUNDEF;
635 info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
637 info.isFunction = isFunc;
640 entry.setValue(info);
644 class RecordStreamer : public MCStreamer {
646 enum State { NeverSeen, Global, Defined, DefinedGlobal, Used };
649 StringMap<State> Symbols;
651 void markDefined(const MCSymbol &Symbol) {
652 State &S = Symbols[Symbol.getName()];
665 void markGlobal(const MCSymbol &Symbol) {
666 State &S = Symbols[Symbol.getName()];
680 void markUsed(const MCSymbol &Symbol) {
681 State &S = Symbols[Symbol.getName()];
695 // FIXME: mostly copied for the obj streamer.
696 void AddValueSymbols(const MCExpr *Value) {
697 switch (Value->getKind()) {
699 // FIXME: What should we do in here?
702 case MCExpr::Constant:
705 case MCExpr::Binary: {
706 const MCBinaryExpr *BE = cast<MCBinaryExpr>(Value);
707 AddValueSymbols(BE->getLHS());
708 AddValueSymbols(BE->getRHS());
712 case MCExpr::SymbolRef:
713 markUsed(cast<MCSymbolRefExpr>(Value)->getSymbol());
717 AddValueSymbols(cast<MCUnaryExpr>(Value)->getSubExpr());
723 typedef StringMap<State>::const_iterator const_iterator;
725 const_iterator begin() {
726 return Symbols.begin();
729 const_iterator end() {
730 return Symbols.end();
733 RecordStreamer(MCContext &Context)
734 : MCStreamer(SK_RecordStreamer, Context) {}
736 virtual void EmitInstruction(const MCInst &Inst) {
738 for (unsigned i = Inst.getNumOperands(); i--; )
739 if (Inst.getOperand(i).isExpr())
740 AddValueSymbols(Inst.getOperand(i).getExpr());
742 virtual void EmitLabel(MCSymbol *Symbol) {
743 Symbol->setSection(*getCurrentSection().first);
744 markDefined(*Symbol);
746 virtual void EmitDebugLabel(MCSymbol *Symbol) {
749 virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
750 // FIXME: should we handle aliases?
751 markDefined(*Symbol);
753 virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute) {
754 if (Attribute == MCSA_Global)
757 virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
758 uint64_t Size , unsigned ByteAlignment) {
759 markDefined(*Symbol);
761 virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
762 unsigned ByteAlignment) {
763 markDefined(*Symbol);
766 virtual void EmitBundleAlignMode(unsigned AlignPow2) {}
767 virtual void EmitBundleLock(bool AlignToEnd) {}
768 virtual void EmitBundleUnlock() {}
771 virtual void ChangeSection(const MCSection *Section,
772 const MCExpr *Subsection) {}
773 virtual void InitToTextSection() {}
774 virtual void InitSections() {}
775 virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) {}
776 virtual void EmitThumbFunc(MCSymbol *Func) {}
777 virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {}
778 virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) {}
779 virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) {}
780 virtual void EmitCOFFSymbolStorageClass(int StorageClass) {}
781 virtual void EmitCOFFSymbolType(int Type) {}
782 virtual void EndCOFFSymbolDef() {}
783 virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {}
784 virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
785 unsigned ByteAlignment) {}
786 virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
787 uint64_t Size, unsigned ByteAlignment) {}
788 virtual void EmitBytes(StringRef Data) {}
789 virtual void EmitValueImpl(const MCExpr *Value, unsigned Size) {}
790 virtual void EmitULEB128Value(const MCExpr *Value) {}
791 virtual void EmitSLEB128Value(const MCExpr *Value) {}
792 virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value,
794 unsigned MaxBytesToEmit) {}
795 virtual void EmitCodeAlignment(unsigned ByteAlignment,
796 unsigned MaxBytesToEmit) {}
797 virtual bool EmitValueToOffset(const MCExpr *Offset,
798 unsigned char Value ) { return false; }
799 virtual void EmitFileDirective(StringRef Filename) {}
800 virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta,
801 const MCSymbol *LastLabel,
802 const MCSymbol *Label,
803 unsigned PointerSize) {}
804 virtual void FinishImpl() {}
806 static bool classof(const MCStreamer *S) {
807 return S->getKind() == SK_RecordStreamer;
810 } // end anonymous namespace
812 /// addAsmGlobalSymbols - Add global symbols from module-level ASM to the
813 /// defined or undefined lists.
814 bool LTOModule::addAsmGlobalSymbols(std::string &errMsg) {
815 const std::string &inlineAsm = _module->getModuleInlineAsm();
816 if (inlineAsm.empty())
819 OwningPtr<RecordStreamer> Streamer(new RecordStreamer(_context));
820 MemoryBuffer *Buffer = MemoryBuffer::getMemBuffer(inlineAsm);
822 SrcMgr.AddNewSourceBuffer(Buffer, SMLoc());
823 OwningPtr<MCAsmParser> Parser(createMCAsmParser(SrcMgr,
825 *_target->getMCAsmInfo()));
826 const Target &T = _target->getTarget();
827 OwningPtr<MCSubtargetInfo>
828 STI(T.createMCSubtargetInfo(_target->getTargetTriple(),
829 _target->getTargetCPU(),
830 _target->getTargetFeatureString()));
831 OwningPtr<MCTargetAsmParser> TAP(T.createMCAsmParser(*STI, *Parser.get()));
833 errMsg = "target " + std::string(T.getName()) +
834 " does not define AsmParser.";
838 Parser->setTargetParser(*TAP);
839 if (Parser->Run(false))
842 for (RecordStreamer::const_iterator i = Streamer->begin(),
843 e = Streamer->end(); i != e; ++i) {
844 StringRef Key = i->first();
845 RecordStreamer::State Value = i->second;
846 if (Value == RecordStreamer::DefinedGlobal)
847 addAsmGlobalSymbol(Key.data(), LTO_SYMBOL_SCOPE_DEFAULT);
848 else if (Value == RecordStreamer::Defined)
849 addAsmGlobalSymbol(Key.data(), LTO_SYMBOL_SCOPE_INTERNAL);
850 else if (Value == RecordStreamer::Global ||
851 Value == RecordStreamer::Used)
852 addAsmGlobalSymbolUndef(Key.data());
858 /// isDeclaration - Return 'true' if the global value is a declaration.
859 static bool isDeclaration(const GlobalValue &V) {
860 if (V.hasAvailableExternallyLinkage())
863 if (V.isMaterializable())
866 return V.isDeclaration();
869 /// parseSymbols - Parse the symbols from the module and model-level ASM and add
870 /// them to either the defined or undefined lists.
871 bool LTOModule::parseSymbols(std::string &errMsg) {
873 for (Module::iterator f = _module->begin(), e = _module->end(); f != e; ++f) {
874 if (isDeclaration(*f))
875 addPotentialUndefinedSymbol(f, true);
877 addDefinedFunctionSymbol(f);
881 for (Module::global_iterator v = _module->global_begin(),
882 e = _module->global_end(); v != e; ++v) {
883 if (isDeclaration(*v))
884 addPotentialUndefinedSymbol(v, false);
886 addDefinedDataSymbol(v);
890 if (addAsmGlobalSymbols(errMsg))
894 for (Module::alias_iterator a = _module->alias_begin(),
895 e = _module->alias_end(); a != e; ++a) {
896 if (isDeclaration(*a->getAliasedGlobal()))
897 // Is an alias to a declaration.
898 addPotentialUndefinedSymbol(a, false);
900 addDefinedDataSymbol(a);
903 // make symbols for all undefines
904 for (StringMap<NameAndAttributes>::iterator u =_undefines.begin(),
905 e = _undefines.end(); u != e; ++u) {
906 // If this symbol also has a definition, then don't make an undefine because
907 // it is a tentative definition.
908 if (_defines.count(u->getKey())) continue;
909 NameAndAttributes info = u->getValue();
910 _symbols.push_back(info);