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			839 lines
		
	
	
		
			28 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			839 lines
		
	
	
		
			28 KiB
		
	
	
	
		
			C++
		
	
	
	
| //===-- LTOModule.cpp - LLVM Link Time Optimizer --------------------------===//
 | |
| //
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| //                     The LLVM Compiler Infrastructure
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| //
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| // This file is distributed under the University of Illinois Open Source
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| // License. See LICENSE.TXT for details.
 | |
| //
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| //===----------------------------------------------------------------------===//
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| //
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| // This file implements the Link Time Optimization library. This library is
 | |
| // intended to be used by linker to optimize code at link time.
 | |
| //
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| //===----------------------------------------------------------------------===//
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| 
 | |
| #include "llvm/LTO/LTOModule.h"
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| #include "llvm/ADT/OwningPtr.h"
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| #include "llvm/ADT/Triple.h"
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| #include "llvm/Bitcode/ReaderWriter.h"
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| #include "llvm/IR/Constants.h"
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| #include "llvm/IR/LLVMContext.h"
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| #include "llvm/IR/Metadata.h"
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| #include "llvm/IR/Module.h"
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| #include "llvm/MC/MCExpr.h"
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| #include "llvm/MC/MCInst.h"
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| #include "llvm/MC/MCInstrInfo.h"
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| #include "llvm/MC/MCParser/MCAsmParser.h"
 | |
| #include "llvm/MC/MCSection.h"
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| #include "llvm/MC/MCStreamer.h"
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| #include "llvm/MC/MCSubtargetInfo.h"
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| #include "llvm/MC/MCSymbol.h"
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| #include "llvm/MC/MCTargetAsmParser.h"
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| #include "llvm/MC/SubtargetFeature.h"
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| #include "llvm/Support/CommandLine.h"
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| #include "llvm/Support/FileSystem.h"
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| #include "llvm/Support/Host.h"
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| #include "llvm/Support/MemoryBuffer.h"
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| #include "llvm/Support/Path.h"
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| #include "llvm/Support/SourceMgr.h"
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| #include "llvm/Support/TargetRegistry.h"
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| #include "llvm/Support/TargetSelect.h"
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| #include "llvm/Support/system_error.h"
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| #include "llvm/Target/TargetLowering.h"
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| #include "llvm/Target/TargetLoweringObjectFile.h"
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| #include "llvm/Target/TargetRegisterInfo.h"
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| #include "llvm/Transforms/Utils/GlobalStatus.h"
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| using namespace llvm;
 | |
| 
 | |
| LTOModule::LTOModule(llvm::Module *m, llvm::TargetMachine *t)
 | |
|   : _module(m), _target(t),
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|     _context(_target->getMCAsmInfo(), _target->getRegisterInfo(), &ObjFileInfo),
 | |
|     _mangler(t->getDataLayout()) {
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|   ObjFileInfo.InitMCObjectFileInfo(t->getTargetTriple(),
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|                                    t->getRelocationModel(), t->getCodeModel(),
 | |
|                                    _context);
 | |
| }
 | |
| 
 | |
| /// isBitcodeFile - Returns 'true' if the file (or memory contents) is LLVM
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| /// bitcode.
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| bool LTOModule::isBitcodeFile(const void *mem, size_t length) {
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|   return sys::fs::identify_magic(StringRef((const char *)mem, length)) ==
 | |
|          sys::fs::file_magic::bitcode;
 | |
| }
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| 
 | |
| bool LTOModule::isBitcodeFile(const char *path) {
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|   sys::fs::file_magic type;
 | |
|   if (sys::fs::identify_magic(path, type))
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|     return false;
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|   return type == sys::fs::file_magic::bitcode;
 | |
| }
 | |
| 
 | |
| /// isBitcodeFileForTarget - Returns 'true' if the file (or memory contents) is
 | |
| /// LLVM bitcode for the specified triple.
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| bool LTOModule::isBitcodeFileForTarget(const void *mem, size_t length,
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|                                        const char *triplePrefix) {
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|   MemoryBuffer *buffer = makeBuffer(mem, length);
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|   if (!buffer)
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|     return false;
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|   return isTargetMatch(buffer, triplePrefix);
 | |
| }
 | |
| 
 | |
| bool LTOModule::isBitcodeFileForTarget(const char *path,
 | |
|                                        const char *triplePrefix) {
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|   OwningPtr<MemoryBuffer> buffer;
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|   if (MemoryBuffer::getFile(path, buffer))
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|     return false;
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|   return isTargetMatch(buffer.take(), triplePrefix);
 | |
| }
 | |
| 
 | |
| /// isTargetMatch - Returns 'true' if the memory buffer is for the specified
 | |
| /// target triple.
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| bool LTOModule::isTargetMatch(MemoryBuffer *buffer, const char *triplePrefix) {
 | |
|   std::string Triple = getBitcodeTargetTriple(buffer, getGlobalContext());
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|   delete buffer;
 | |
|   return strncmp(Triple.c_str(), triplePrefix, strlen(triplePrefix)) == 0;
 | |
| }
 | |
| 
 | |
| /// makeLTOModule - Create an LTOModule. N.B. These methods take ownership of
 | |
| /// the buffer.
 | |
| LTOModule *LTOModule::makeLTOModule(const char *path, TargetOptions options,
 | |
|                                     std::string &errMsg) {
 | |
|   OwningPtr<MemoryBuffer> buffer;
 | |
|   if (error_code ec = MemoryBuffer::getFile(path, buffer)) {
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|     errMsg = ec.message();
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|     return NULL;
 | |
|   }
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|   return makeLTOModule(buffer.take(), options, errMsg);
 | |
| }
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| 
 | |
| LTOModule *LTOModule::makeLTOModule(int fd, const char *path,
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|                                     size_t size, TargetOptions options,
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|                                     std::string &errMsg) {
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|   return makeLTOModule(fd, path, size, 0, options, errMsg);
 | |
| }
 | |
| 
 | |
| LTOModule *LTOModule::makeLTOModule(int fd, const char *path,
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|                                     size_t map_size,
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|                                     off_t offset,
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|                                     TargetOptions options,
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|                                     std::string &errMsg) {
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|   OwningPtr<MemoryBuffer> buffer;
 | |
|   if (error_code ec =
 | |
|           MemoryBuffer::getOpenFileSlice(fd, path, buffer, map_size, offset)) {
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|     errMsg = ec.message();
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|     return NULL;
 | |
|   }
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|   return makeLTOModule(buffer.take(), options, errMsg);
 | |
| }
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| 
 | |
| LTOModule *LTOModule::makeLTOModule(const void *mem, size_t length,
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|                                     TargetOptions options,
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|                                     std::string &errMsg, StringRef path) {
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|   OwningPtr<MemoryBuffer> buffer(makeBuffer(mem, length, path));
 | |
|   if (!buffer)
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|     return NULL;
 | |
|   return makeLTOModule(buffer.take(), options, errMsg);
 | |
| }
 | |
| 
 | |
| LTOModule *LTOModule::makeLTOModule(MemoryBuffer *buffer,
 | |
|                                     TargetOptions options,
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|                                     std::string &errMsg) {
 | |
|   // parse bitcode buffer
 | |
|   ErrorOr<Module *> ModuleOrErr =
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|       getLazyBitcodeModule(buffer, getGlobalContext());
 | |
|   if (error_code EC = ModuleOrErr.getError()) {
 | |
|     errMsg = EC.message();
 | |
|     delete buffer;
 | |
|     return NULL;
 | |
|   }
 | |
|   OwningPtr<Module> m(ModuleOrErr.get());
 | |
| 
 | |
|   std::string TripleStr = m->getTargetTriple();
 | |
|   if (TripleStr.empty())
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|     TripleStr = sys::getDefaultTargetTriple();
 | |
|   llvm::Triple Triple(TripleStr);
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| 
 | |
|   // find machine architecture for this module
 | |
|   const Target *march = TargetRegistry::lookupTarget(TripleStr, errMsg);
 | |
|   if (!march)
 | |
|     return NULL;
 | |
| 
 | |
|   // construct LTOModule, hand over ownership of module and target
 | |
|   SubtargetFeatures Features;
 | |
|   Features.getDefaultSubtargetFeatures(Triple);
 | |
|   std::string FeatureStr = Features.getString();
 | |
|   // Set a default CPU for Darwin triples.
 | |
|   std::string CPU;
 | |
|   if (Triple.isOSDarwin()) {
 | |
|     if (Triple.getArch() == llvm::Triple::x86_64)
 | |
|       CPU = "core2";
 | |
|     else if (Triple.getArch() == llvm::Triple::x86)
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|       CPU = "yonah";
 | |
|   }
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| 
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|   TargetMachine *target = march->createTargetMachine(TripleStr, CPU, FeatureStr,
 | |
|                                                      options);
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|   m->materializeAllPermanently();
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| 
 | |
|   LTOModule *Ret = new LTOModule(m.take(), target);
 | |
|   if (Ret->parseSymbols(errMsg)) {
 | |
|     delete Ret;
 | |
|     return NULL;
 | |
|   }
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| 
 | |
|   Ret->parseMetadata();
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| 
 | |
|   return Ret;
 | |
| }
 | |
| 
 | |
| /// Create a MemoryBuffer from a memory range with an optional name.
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| MemoryBuffer *LTOModule::makeBuffer(const void *mem, size_t length,
 | |
|                                     StringRef name) {
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|   const char *startPtr = (const char*)mem;
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|   return MemoryBuffer::getMemBuffer(StringRef(startPtr, length), name, false);
 | |
| }
 | |
| 
 | |
| /// objcClassNameFromExpression - Get string that the data pointer points to.
 | |
| bool
 | |
| LTOModule::objcClassNameFromExpression(const Constant *c, std::string &name) {
 | |
|   if (const ConstantExpr *ce = dyn_cast<ConstantExpr>(c)) {
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|     Constant *op = ce->getOperand(0);
 | |
|     if (GlobalVariable *gvn = dyn_cast<GlobalVariable>(op)) {
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|       Constant *cn = gvn->getInitializer();
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|       if (ConstantDataArray *ca = dyn_cast<ConstantDataArray>(cn)) {
 | |
|         if (ca->isCString()) {
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|           name = ".objc_class_name_" + ca->getAsCString().str();
 | |
|           return true;
 | |
|         }
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|       }
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|     }
 | |
|   }
 | |
|   return false;
 | |
| }
 | |
| 
 | |
| /// addObjCClass - Parse i386/ppc ObjC class data structure.
 | |
| void LTOModule::addObjCClass(const GlobalVariable *clgv) {
 | |
|   const ConstantStruct *c = dyn_cast<ConstantStruct>(clgv->getInitializer());
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|   if (!c) return;
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| 
 | |
|   // second slot in __OBJC,__class is pointer to superclass name
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|   std::string superclassName;
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|   if (objcClassNameFromExpression(c->getOperand(1), superclassName)) {
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|     NameAndAttributes info;
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|     StringMap<NameAndAttributes>::value_type &entry =
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|       _undefines.GetOrCreateValue(superclassName);
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|     if (!entry.getValue().name) {
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|       const char *symbolName = entry.getKey().data();
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|       info.name = symbolName;
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|       info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
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|       info.isFunction = false;
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|       info.symbol = clgv;
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|       entry.setValue(info);
 | |
|     }
 | |
|   }
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| 
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|   // third slot in __OBJC,__class is pointer to class name
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|   std::string className;
 | |
|   if (objcClassNameFromExpression(c->getOperand(2), className)) {
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|     StringSet::value_type &entry = _defines.GetOrCreateValue(className);
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|     entry.setValue(1);
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| 
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|     NameAndAttributes info;
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|     info.name = entry.getKey().data();
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|     info.attributes = LTO_SYMBOL_PERMISSIONS_DATA |
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|       LTO_SYMBOL_DEFINITION_REGULAR | LTO_SYMBOL_SCOPE_DEFAULT;
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|     info.isFunction = false;
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|     info.symbol = clgv;
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|     _symbols.push_back(info);
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|   }
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| }
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| 
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| /// addObjCCategory - Parse i386/ppc ObjC category data structure.
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| void LTOModule::addObjCCategory(const GlobalVariable *clgv) {
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|   const ConstantStruct *c = dyn_cast<ConstantStruct>(clgv->getInitializer());
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|   if (!c) return;
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| 
 | |
|   // second slot in __OBJC,__category is pointer to target class name
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|   std::string targetclassName;
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|   if (!objcClassNameFromExpression(c->getOperand(1), targetclassName))
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|     return;
 | |
| 
 | |
|   NameAndAttributes info;
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|   StringMap<NameAndAttributes>::value_type &entry =
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|     _undefines.GetOrCreateValue(targetclassName);
 | |
| 
 | |
|   if (entry.getValue().name)
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|     return;
 | |
| 
 | |
|   const char *symbolName = entry.getKey().data();
 | |
|   info.name = symbolName;
 | |
|   info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
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|   info.isFunction = false;
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|   info.symbol = clgv;
 | |
|   entry.setValue(info);
 | |
| }
 | |
| 
 | |
| /// addObjCClassRef - Parse i386/ppc ObjC class list data structure.
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| void LTOModule::addObjCClassRef(const GlobalVariable *clgv) {
 | |
|   std::string targetclassName;
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|   if (!objcClassNameFromExpression(clgv->getInitializer(), targetclassName))
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|     return;
 | |
| 
 | |
|   NameAndAttributes info;
 | |
|   StringMap<NameAndAttributes>::value_type &entry =
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|     _undefines.GetOrCreateValue(targetclassName);
 | |
|   if (entry.getValue().name)
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|     return;
 | |
| 
 | |
|   const char *symbolName = entry.getKey().data();
 | |
|   info.name = symbolName;
 | |
|   info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
 | |
|   info.isFunction = false;
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|   info.symbol = clgv;
 | |
|   entry.setValue(info);
 | |
| }
 | |
| 
 | |
| /// addDefinedDataSymbol - Add a data symbol as defined to the list.
 | |
| void LTOModule::addDefinedDataSymbol(const GlobalValue *v) {
 | |
|   // Add to list of defined symbols.
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|   addDefinedSymbol(v, false);
 | |
| 
 | |
|   if (!v->hasSection() /* || !isTargetDarwin */)
 | |
|     return;
 | |
| 
 | |
|   // Special case i386/ppc ObjC data structures in magic sections:
 | |
|   // The issue is that the old ObjC object format did some strange
 | |
|   // contortions to avoid real linker symbols.  For instance, the
 | |
|   // ObjC class data structure is allocated statically in the executable
 | |
|   // that defines that class.  That data structures contains a pointer to
 | |
|   // its superclass.  But instead of just initializing that part of the
 | |
|   // struct to the address of its superclass, and letting the static and
 | |
|   // dynamic linkers do the rest, the runtime works by having that field
 | |
|   // instead point to a C-string that is the name of the superclass.
 | |
|   // At runtime the objc initialization updates that pointer and sets
 | |
|   // it to point to the actual super class.  As far as the linker
 | |
|   // knows it is just a pointer to a string.  But then someone wanted the
 | |
|   // linker to issue errors at build time if the superclass was not found.
 | |
|   // So they figured out a way in mach-o object format to use an absolute
 | |
|   // symbols (.objc_class_name_Foo = 0) and a floating reference
 | |
|   // (.reference .objc_class_name_Bar) to cause the linker into erroring when
 | |
|   // a class was missing.
 | |
|   // The following synthesizes the implicit .objc_* symbols for the linker
 | |
|   // from the ObjC data structures generated by the front end.
 | |
| 
 | |
|   // special case if this data blob is an ObjC class definition
 | |
|   if (v->getSection().compare(0, 15, "__OBJC,__class,") == 0) {
 | |
|     if (const GlobalVariable *gv = dyn_cast<GlobalVariable>(v)) {
 | |
|       addObjCClass(gv);
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   // special case if this data blob is an ObjC category definition
 | |
|   else if (v->getSection().compare(0, 18, "__OBJC,__category,") == 0) {
 | |
|     if (const GlobalVariable *gv = dyn_cast<GlobalVariable>(v)) {
 | |
|       addObjCCategory(gv);
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   // special case if this data blob is the list of referenced classes
 | |
|   else if (v->getSection().compare(0, 18, "__OBJC,__cls_refs,") == 0) {
 | |
|     if (const GlobalVariable *gv = dyn_cast<GlobalVariable>(v)) {
 | |
|       addObjCClassRef(gv);
 | |
|     }
 | |
|   }
 | |
| }
 | |
| 
 | |
| /// addDefinedFunctionSymbol - Add a function symbol as defined to the list.
 | |
| void LTOModule::addDefinedFunctionSymbol(const Function *f) {
 | |
|   // add to list of defined symbols
 | |
|   addDefinedSymbol(f, true);
 | |
| }
 | |
| 
 | |
| static bool canBeHidden(const GlobalValue *GV) {
 | |
|   // FIXME: this is duplicated with another static function in AsmPrinter.cpp
 | |
|   GlobalValue::LinkageTypes L = GV->getLinkage();
 | |
| 
 | |
|   if (L != GlobalValue::LinkOnceODRLinkage)
 | |
|     return false;
 | |
| 
 | |
|   if (GV->hasUnnamedAddr())
 | |
|     return true;
 | |
| 
 | |
|   // If it is a non constant variable, it needs to be uniqued across shared
 | |
|   // objects.
 | |
|   if (const GlobalVariable *Var = dyn_cast<GlobalVariable>(GV)) {
 | |
|     if (!Var->isConstant())
 | |
|       return false;
 | |
|   }
 | |
| 
 | |
|   GlobalStatus GS;
 | |
|   if (GlobalStatus::analyzeGlobal(GV, GS))
 | |
|     return false;
 | |
| 
 | |
|   return !GS.IsCompared;
 | |
| }
 | |
| 
 | |
| /// addDefinedSymbol - Add a defined symbol to the list.
 | |
| void LTOModule::addDefinedSymbol(const GlobalValue *def, bool isFunction) {
 | |
|   // ignore all llvm.* symbols
 | |
|   if (def->getName().startswith("llvm."))
 | |
|     return;
 | |
| 
 | |
|   // string is owned by _defines
 | |
|   SmallString<64> Buffer;
 | |
|   _mangler.getNameWithPrefix(Buffer, def);
 | |
| 
 | |
|   // set alignment part log2() can have rounding errors
 | |
|   uint32_t align = def->getAlignment();
 | |
|   uint32_t attr = align ? countTrailingZeros(def->getAlignment()) : 0;
 | |
| 
 | |
|   // set permissions part
 | |
|   if (isFunction) {
 | |
|     attr |= LTO_SYMBOL_PERMISSIONS_CODE;
 | |
|   } else {
 | |
|     const GlobalVariable *gv = dyn_cast<GlobalVariable>(def);
 | |
|     if (gv && gv->isConstant())
 | |
|       attr |= LTO_SYMBOL_PERMISSIONS_RODATA;
 | |
|     else
 | |
|       attr |= LTO_SYMBOL_PERMISSIONS_DATA;
 | |
|   }
 | |
| 
 | |
|   // set definition part
 | |
|   if (def->hasWeakLinkage() || def->hasLinkOnceLinkage() ||
 | |
|       def->hasLinkerPrivateWeakLinkage())
 | |
|     attr |= LTO_SYMBOL_DEFINITION_WEAK;
 | |
|   else if (def->hasCommonLinkage())
 | |
|     attr |= LTO_SYMBOL_DEFINITION_TENTATIVE;
 | |
|   else
 | |
|     attr |= LTO_SYMBOL_DEFINITION_REGULAR;
 | |
| 
 | |
|   // set scope part
 | |
|   if (def->hasHiddenVisibility())
 | |
|     attr |= LTO_SYMBOL_SCOPE_HIDDEN;
 | |
|   else if (def->hasProtectedVisibility())
 | |
|     attr |= LTO_SYMBOL_SCOPE_PROTECTED;
 | |
|   else if (canBeHidden(def))
 | |
|     attr |= LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN;
 | |
|   else if (def->hasExternalLinkage() || def->hasWeakLinkage() ||
 | |
|            def->hasLinkOnceLinkage() || def->hasCommonLinkage() ||
 | |
|            def->hasLinkerPrivateWeakLinkage())
 | |
|     attr |= LTO_SYMBOL_SCOPE_DEFAULT;
 | |
|   else
 | |
|     attr |= LTO_SYMBOL_SCOPE_INTERNAL;
 | |
| 
 | |
|   StringSet::value_type &entry = _defines.GetOrCreateValue(Buffer);
 | |
|   entry.setValue(1);
 | |
| 
 | |
|   // fill information structure
 | |
|   NameAndAttributes info;
 | |
|   StringRef Name = entry.getKey();
 | |
|   info.name = Name.data();
 | |
|   assert(info.name[Name.size()] == '\0');
 | |
|   info.attributes = attr;
 | |
|   info.isFunction = isFunction;
 | |
|   info.symbol = def;
 | |
| 
 | |
|   // add to table of symbols
 | |
|   _symbols.push_back(info);
 | |
| }
 | |
| 
 | |
| /// addAsmGlobalSymbol - Add a global symbol from module-level ASM to the
 | |
| /// defined list.
 | |
| void LTOModule::addAsmGlobalSymbol(const char *name,
 | |
|                                    lto_symbol_attributes scope) {
 | |
|   StringSet::value_type &entry = _defines.GetOrCreateValue(name);
 | |
| 
 | |
|   // only add new define if not already defined
 | |
|   if (entry.getValue())
 | |
|     return;
 | |
| 
 | |
|   entry.setValue(1);
 | |
| 
 | |
|   NameAndAttributes &info = _undefines[entry.getKey().data()];
 | |
| 
 | |
|   if (info.symbol == 0) {
 | |
|     // FIXME: This is trying to take care of module ASM like this:
 | |
|     //
 | |
|     //   module asm ".zerofill __FOO, __foo, _bar_baz_qux, 0"
 | |
|     //
 | |
|     // but is gross and its mother dresses it funny. Have the ASM parser give us
 | |
|     // more details for this type of situation so that we're not guessing so
 | |
|     // much.
 | |
| 
 | |
|     // fill information structure
 | |
|     info.name = entry.getKey().data();
 | |
|     info.attributes =
 | |
|       LTO_SYMBOL_PERMISSIONS_DATA | LTO_SYMBOL_DEFINITION_REGULAR | scope;
 | |
|     info.isFunction = false;
 | |
|     info.symbol = 0;
 | |
| 
 | |
|     // add to table of symbols
 | |
|     _symbols.push_back(info);
 | |
|     return;
 | |
|   }
 | |
| 
 | |
|   if (info.isFunction)
 | |
|     addDefinedFunctionSymbol(cast<Function>(info.symbol));
 | |
|   else
 | |
|     addDefinedDataSymbol(info.symbol);
 | |
| 
 | |
|   _symbols.back().attributes &= ~LTO_SYMBOL_SCOPE_MASK;
 | |
|   _symbols.back().attributes |= scope;
 | |
| }
 | |
| 
 | |
| /// addAsmGlobalSymbolUndef - Add a global symbol from module-level ASM to the
 | |
| /// undefined list.
 | |
| void LTOModule::addAsmGlobalSymbolUndef(const char *name) {
 | |
|   StringMap<NameAndAttributes>::value_type &entry =
 | |
|     _undefines.GetOrCreateValue(name);
 | |
| 
 | |
|   _asm_undefines.push_back(entry.getKey().data());
 | |
| 
 | |
|   // we already have the symbol
 | |
|   if (entry.getValue().name)
 | |
|     return;
 | |
| 
 | |
|   uint32_t attr = LTO_SYMBOL_DEFINITION_UNDEFINED;;
 | |
|   attr |= LTO_SYMBOL_SCOPE_DEFAULT;
 | |
|   NameAndAttributes info;
 | |
|   info.name = entry.getKey().data();
 | |
|   info.attributes = attr;
 | |
|   info.isFunction = false;
 | |
|   info.symbol = 0;
 | |
| 
 | |
|   entry.setValue(info);
 | |
| }
 | |
| 
 | |
| /// addPotentialUndefinedSymbol - Add a symbol which isn't defined just yet to a
 | |
| /// list to be resolved later.
 | |
| void
 | |
| LTOModule::addPotentialUndefinedSymbol(const GlobalValue *decl, bool isFunc) {
 | |
|   // ignore all llvm.* symbols
 | |
|   if (decl->getName().startswith("llvm."))
 | |
|     return;
 | |
| 
 | |
|   // ignore all aliases
 | |
|   if (isa<GlobalAlias>(decl))
 | |
|     return;
 | |
| 
 | |
|   SmallString<64> name;
 | |
|   _mangler.getNameWithPrefix(name, decl);
 | |
| 
 | |
|   StringMap<NameAndAttributes>::value_type &entry =
 | |
|     _undefines.GetOrCreateValue(name);
 | |
| 
 | |
|   // we already have the symbol
 | |
|   if (entry.getValue().name)
 | |
|     return;
 | |
| 
 | |
|   NameAndAttributes info;
 | |
| 
 | |
|   info.name = entry.getKey().data();
 | |
| 
 | |
|   if (decl->hasExternalWeakLinkage())
 | |
|     info.attributes = LTO_SYMBOL_DEFINITION_WEAKUNDEF;
 | |
|   else
 | |
|     info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
 | |
| 
 | |
|   info.isFunction = isFunc;
 | |
|   info.symbol = decl;
 | |
| 
 | |
|   entry.setValue(info);
 | |
| }
 | |
| 
 | |
| namespace {
 | |
| 
 | |
|   class RecordStreamer : public MCStreamer {
 | |
|   public:
 | |
|     enum State { NeverSeen, Global, Defined, DefinedGlobal, Used };
 | |
| 
 | |
|   private:
 | |
|     StringMap<State> Symbols;
 | |
| 
 | |
|     void markDefined(const MCSymbol &Symbol) {
 | |
|       State &S = Symbols[Symbol.getName()];
 | |
|       switch (S) {
 | |
|       case DefinedGlobal:
 | |
|       case Global:
 | |
|         S = DefinedGlobal;
 | |
|         break;
 | |
|       case NeverSeen:
 | |
|       case Defined:
 | |
|       case Used:
 | |
|         S = Defined;
 | |
|         break;
 | |
|       }
 | |
|     }
 | |
|     void markGlobal(const MCSymbol &Symbol) {
 | |
|       State &S = Symbols[Symbol.getName()];
 | |
|       switch (S) {
 | |
|       case DefinedGlobal:
 | |
|       case Defined:
 | |
|         S = DefinedGlobal;
 | |
|         break;
 | |
| 
 | |
|       case NeverSeen:
 | |
|       case Global:
 | |
|       case Used:
 | |
|         S = Global;
 | |
|         break;
 | |
|       }
 | |
|     }
 | |
|     void markUsed(const MCSymbol &Symbol) {
 | |
|       State &S = Symbols[Symbol.getName()];
 | |
|       switch (S) {
 | |
|       case DefinedGlobal:
 | |
|       case Defined:
 | |
|       case Global:
 | |
|         break;
 | |
| 
 | |
|       case NeverSeen:
 | |
|       case Used:
 | |
|         S = Used;
 | |
|         break;
 | |
|       }
 | |
|     }
 | |
| 
 | |
|     // FIXME: mostly copied for the obj streamer.
 | |
|     void AddValueSymbols(const MCExpr *Value) {
 | |
|       switch (Value->getKind()) {
 | |
|       case MCExpr::Target:
 | |
|         // FIXME: What should we do in here?
 | |
|         break;
 | |
| 
 | |
|       case MCExpr::Constant:
 | |
|         break;
 | |
| 
 | |
|       case MCExpr::Binary: {
 | |
|         const MCBinaryExpr *BE = cast<MCBinaryExpr>(Value);
 | |
|         AddValueSymbols(BE->getLHS());
 | |
|         AddValueSymbols(BE->getRHS());
 | |
|         break;
 | |
|       }
 | |
| 
 | |
|       case MCExpr::SymbolRef:
 | |
|         markUsed(cast<MCSymbolRefExpr>(Value)->getSymbol());
 | |
|         break;
 | |
| 
 | |
|       case MCExpr::Unary:
 | |
|         AddValueSymbols(cast<MCUnaryExpr>(Value)->getSubExpr());
 | |
|         break;
 | |
|       }
 | |
|     }
 | |
| 
 | |
|   public:
 | |
|     typedef StringMap<State>::const_iterator const_iterator;
 | |
| 
 | |
|     const_iterator begin() {
 | |
|       return Symbols.begin();
 | |
|     }
 | |
| 
 | |
|     const_iterator end() {
 | |
|       return Symbols.end();
 | |
|     }
 | |
| 
 | |
|     RecordStreamer(MCContext &Context) : MCStreamer(Context) {}
 | |
| 
 | |
|     virtual void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI) {
 | |
|       // Scan for values.
 | |
|       for (unsigned i = Inst.getNumOperands(); i--; )
 | |
|         if (Inst.getOperand(i).isExpr())
 | |
|           AddValueSymbols(Inst.getOperand(i).getExpr());
 | |
|     }
 | |
|     virtual void EmitLabel(MCSymbol *Symbol) {
 | |
|       Symbol->setSection(*getCurrentSection().first);
 | |
|       markDefined(*Symbol);
 | |
|     }
 | |
|     virtual void EmitDebugLabel(MCSymbol *Symbol) {
 | |
|       EmitLabel(Symbol);
 | |
|     }
 | |
|     virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
 | |
|       // FIXME: should we handle aliases?
 | |
|       markDefined(*Symbol);
 | |
|     }
 | |
|     virtual bool EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute) {
 | |
|       if (Attribute == MCSA_Global)
 | |
|         markGlobal(*Symbol);
 | |
|       return true;
 | |
|     }
 | |
|     virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
 | |
|                               uint64_t Size , unsigned ByteAlignment) {
 | |
|       markDefined(*Symbol);
 | |
|     }
 | |
|     virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
 | |
|                                   unsigned ByteAlignment) {
 | |
|       markDefined(*Symbol);
 | |
|     }
 | |
| 
 | |
|     virtual void EmitBundleAlignMode(unsigned AlignPow2) {}
 | |
|     virtual void EmitBundleLock(bool AlignToEnd) {}
 | |
|     virtual void EmitBundleUnlock() {}
 | |
| 
 | |
|     // Noop calls.
 | |
|     virtual void ChangeSection(const MCSection *Section,
 | |
|                                const MCExpr *Subsection) {}
 | |
|     virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) {}
 | |
|     virtual void EmitThumbFunc(MCSymbol *Func) {}
 | |
|     virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {}
 | |
|     virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) {}
 | |
|     virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) {}
 | |
|     virtual void EmitCOFFSymbolStorageClass(int StorageClass) {}
 | |
|     virtual void EmitCOFFSymbolType(int Type) {}
 | |
|     virtual void EndCOFFSymbolDef() {}
 | |
|     virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {}
 | |
|     virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
 | |
|                                        unsigned ByteAlignment) {}
 | |
|     virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
 | |
|                                 uint64_t Size, unsigned ByteAlignment) {}
 | |
|     virtual void EmitBytes(StringRef Data) {}
 | |
|     virtual void EmitValueImpl(const MCExpr *Value, unsigned Size) {}
 | |
|     virtual void EmitULEB128Value(const MCExpr *Value) {}
 | |
|     virtual void EmitSLEB128Value(const MCExpr *Value) {}
 | |
|     virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value,
 | |
|                                       unsigned ValueSize,
 | |
|                                       unsigned MaxBytesToEmit) {}
 | |
|     virtual void EmitCodeAlignment(unsigned ByteAlignment,
 | |
|                                    unsigned MaxBytesToEmit) {}
 | |
|     virtual bool EmitValueToOffset(const MCExpr *Offset,
 | |
|                                    unsigned char Value ) { return false; }
 | |
|     virtual void EmitFileDirective(StringRef Filename) {}
 | |
|     virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta,
 | |
|                                           const MCSymbol *LastLabel,
 | |
|                                           const MCSymbol *Label,
 | |
|                                           unsigned PointerSize) {}
 | |
|     virtual void FinishImpl() {}
 | |
|     virtual void EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) {
 | |
|       RecordProcEnd(Frame);
 | |
|     }
 | |
|   };
 | |
| } // end anonymous namespace
 | |
| 
 | |
| /// addAsmGlobalSymbols - Add global symbols from module-level ASM to the
 | |
| /// defined or undefined lists.
 | |
| bool LTOModule::addAsmGlobalSymbols(std::string &errMsg) {
 | |
|   const std::string &inlineAsm = _module->getModuleInlineAsm();
 | |
|   if (inlineAsm.empty())
 | |
|     return false;
 | |
| 
 | |
|   OwningPtr<RecordStreamer> Streamer(new RecordStreamer(_context));
 | |
|   MemoryBuffer *Buffer = MemoryBuffer::getMemBuffer(inlineAsm);
 | |
|   SourceMgr SrcMgr;
 | |
|   SrcMgr.AddNewSourceBuffer(Buffer, SMLoc());
 | |
|   OwningPtr<MCAsmParser> Parser(createMCAsmParser(SrcMgr,
 | |
|                                                   _context, *Streamer,
 | |
|                                                   *_target->getMCAsmInfo()));
 | |
|   const Target &T = _target->getTarget();
 | |
|   OwningPtr<MCInstrInfo> MCII(T.createMCInstrInfo());
 | |
|   OwningPtr<MCSubtargetInfo>
 | |
|     STI(T.createMCSubtargetInfo(_target->getTargetTriple(),
 | |
|                                 _target->getTargetCPU(),
 | |
|                                 _target->getTargetFeatureString()));
 | |
|   OwningPtr<MCTargetAsmParser> TAP(T.createMCAsmParser(*STI, *Parser.get(), *MCII));
 | |
|   if (!TAP) {
 | |
|     errMsg = "target " + std::string(T.getName()) +
 | |
|       " does not define AsmParser.";
 | |
|     return true;
 | |
|   }
 | |
| 
 | |
|   Parser->setTargetParser(*TAP);
 | |
|   if (Parser->Run(false))
 | |
|     return true;
 | |
| 
 | |
|   for (RecordStreamer::const_iterator i = Streamer->begin(),
 | |
|          e = Streamer->end(); i != e; ++i) {
 | |
|     StringRef Key = i->first();
 | |
|     RecordStreamer::State Value = i->second;
 | |
|     if (Value == RecordStreamer::DefinedGlobal)
 | |
|       addAsmGlobalSymbol(Key.data(), LTO_SYMBOL_SCOPE_DEFAULT);
 | |
|     else if (Value == RecordStreamer::Defined)
 | |
|       addAsmGlobalSymbol(Key.data(), LTO_SYMBOL_SCOPE_INTERNAL);
 | |
|     else if (Value == RecordStreamer::Global ||
 | |
|              Value == RecordStreamer::Used)
 | |
|       addAsmGlobalSymbolUndef(Key.data());
 | |
|   }
 | |
| 
 | |
|   return false;
 | |
| }
 | |
| 
 | |
| /// isDeclaration - Return 'true' if the global value is a declaration.
 | |
| static bool isDeclaration(const GlobalValue &V) {
 | |
|   if (V.hasAvailableExternallyLinkage())
 | |
|     return true;
 | |
| 
 | |
|   if (V.isMaterializable())
 | |
|     return false;
 | |
| 
 | |
|   return V.isDeclaration();
 | |
| }
 | |
| 
 | |
| /// parseSymbols - Parse the symbols from the module and model-level ASM and add
 | |
| /// them to either the defined or undefined lists.
 | |
| bool LTOModule::parseSymbols(std::string &errMsg) {
 | |
|   // add functions
 | |
|   for (Module::iterator f = _module->begin(), e = _module->end(); f != e; ++f) {
 | |
|     if (isDeclaration(*f))
 | |
|       addPotentialUndefinedSymbol(f, true);
 | |
|     else
 | |
|       addDefinedFunctionSymbol(f);
 | |
|   }
 | |
| 
 | |
|   // add data
 | |
|   for (Module::global_iterator v = _module->global_begin(),
 | |
|          e = _module->global_end(); v !=  e; ++v) {
 | |
|     if (isDeclaration(*v))
 | |
|       addPotentialUndefinedSymbol(v, false);
 | |
|     else
 | |
|       addDefinedDataSymbol(v);
 | |
|   }
 | |
| 
 | |
|   // add asm globals
 | |
|   if (addAsmGlobalSymbols(errMsg))
 | |
|     return true;
 | |
| 
 | |
|   // add aliases
 | |
|   for (Module::alias_iterator a = _module->alias_begin(),
 | |
|          e = _module->alias_end(); a != e; ++a) {
 | |
|     if (isDeclaration(*a->getAliasedGlobal()))
 | |
|       // Is an alias to a declaration.
 | |
|       addPotentialUndefinedSymbol(a, false);
 | |
|     else
 | |
|       addDefinedDataSymbol(a);
 | |
|   }
 | |
| 
 | |
|   // make symbols for all undefines
 | |
|   for (StringMap<NameAndAttributes>::iterator u =_undefines.begin(),
 | |
|          e = _undefines.end(); u != e; ++u) {
 | |
|     // If this symbol also has a definition, then don't make an undefine because
 | |
|     // it is a tentative definition.
 | |
|     if (_defines.count(u->getKey())) continue;
 | |
|     NameAndAttributes info = u->getValue();
 | |
|     _symbols.push_back(info);
 | |
|   }
 | |
| 
 | |
|   return false;
 | |
| }
 | |
| 
 | |
| /// parseMetadata - Parse metadata from the module
 | |
| void LTOModule::parseMetadata() {
 | |
|   // Linker Options
 | |
|   if (Value *Val = _module->getModuleFlag("Linker Options")) {
 | |
|     MDNode *LinkerOptions = cast<MDNode>(Val);
 | |
|     for (unsigned i = 0, e = LinkerOptions->getNumOperands(); i != e; ++i) {
 | |
|       MDNode *MDOptions = cast<MDNode>(LinkerOptions->getOperand(i));
 | |
|       for (unsigned ii = 0, ie = MDOptions->getNumOperands(); ii != ie; ++ii) {
 | |
|         MDString *MDOption = cast<MDString>(MDOptions->getOperand(ii));
 | |
|         StringRef Op = _linkeropt_strings.
 | |
|             GetOrCreateValue(MDOption->getString()).getKey();
 | |
|         StringRef DepLibName = _target->getTargetLowering()->
 | |
|             getObjFileLowering().getDepLibFromLinkerOpt(Op);
 | |
|         if (!DepLibName.empty())
 | |
|           _deplibs.push_back(DepLibName.data());
 | |
|         else if (!Op.empty())
 | |
|           _linkeropts.push_back(Op.data());
 | |
|       }
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   // Add other interesting metadata here.
 | |
| }
 |