Beispiel #1
0
Module *llvm::CloneModule(const Module *M,
                          DenseMap<const Value*, Value*> &ValueMap) {
  // First off, we need to create the new module...
  Module *New = new Module(M->getModuleIdentifier());
  New->setDataLayout(M->getDataLayout());
  New->setTargetTriple(M->getTargetTriple());
  New->setModuleInlineAsm(M->getModuleInlineAsm());

  // Copy all of the type symbol table entries over.
  const TypeSymbolTable &TST = M->getTypeSymbolTable();
  for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end(); 
       TI != TE; ++TI)
    New->addTypeName(TI->first, TI->second);
  
  // Copy all of the dependent libraries over.
  for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
    New->addLibrary(*I);

  // Loop over all of the global variables, making corresponding globals in the
  // new module.  Here we add them to the ValueMap and to the new Module.  We
  // don't worry about attributes or initializers, they will come later.
  //
  for (Module::const_global_iterator I = M->global_begin(), E = M->global_end();
       I != E; ++I) {
    GlobalVariable *GV = new GlobalVariable(I->getType()->getElementType(),
                                            false,
                                            GlobalValue::ExternalLinkage, 0,
                                            I->getName(), New);
    GV->setAlignment(I->getAlignment());
    ValueMap[I] = GV;
  }

  // Loop over the functions in the module, making external functions as before
  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I) {
    Function *NF =
      Function::Create(cast<FunctionType>(I->getType()->getElementType()),
                       GlobalValue::ExternalLinkage, I->getName(), New);
    NF->copyAttributesFrom(I);
    ValueMap[I] = NF;
  }

  // Loop over the aliases in the module
  for (Module::const_alias_iterator I = M->alias_begin(), E = M->alias_end();
       I != E; ++I)
    ValueMap[I] = new GlobalAlias(I->getType(), GlobalAlias::ExternalLinkage,
                                  I->getName(), NULL, New);
  
  // Now that all of the things that global variable initializer can refer to
  // have been created, loop through and copy the global variable referrers
  // over...  We also set the attributes on the global now.
  //
  for (Module::const_global_iterator I = M->global_begin(), E = M->global_end();
       I != E; ++I) {
    GlobalVariable *GV = cast<GlobalVariable>(ValueMap[I]);
    if (I->hasInitializer())
      GV->setInitializer(cast<Constant>(MapValue(I->getInitializer(),
                                                 ValueMap)));
    GV->setLinkage(I->getLinkage());
    GV->setThreadLocal(I->isThreadLocal());
    GV->setConstant(I->isConstant());
  }

  // Similarly, copy over function bodies now...
  //
  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I) {
    Function *F = cast<Function>(ValueMap[I]);
    if (!I->isDeclaration()) {
      Function::arg_iterator DestI = F->arg_begin();
      for (Function::const_arg_iterator J = I->arg_begin(); J != I->arg_end();
           ++J) {
        DestI->setName(J->getName());
        ValueMap[J] = DestI++;
      }

      std::vector<ReturnInst*> Returns;  // Ignore returns cloned...
      CloneFunctionInto(F, I, ValueMap, Returns);
    }

    F->setLinkage(I->getLinkage());
  }

  // And aliases
  for (Module::const_alias_iterator I = M->alias_begin(), E = M->alias_end();
       I != E; ++I) {
    GlobalAlias *GA = cast<GlobalAlias>(ValueMap[I]);
    GA->setLinkage(I->getLinkage());
    if (const Constant* C = I->getAliasee())
      GA->setAliasee(cast<Constant>(MapValue(C, ValueMap)));
  }
  
  return New;
}
// make_decl_llvm - Create the DECL_RTL for a VAR_DECL or FUNCTION_DECL.  DECL
// should have static storage duration.  In other words, it should not be an
// automatic variable, including PARM_DECLs.
//
// There is, however, one exception: this function handles variables explicitly
// placed in a particular register by the user.
//
// This function corresponds to make_decl_rtl in varasm.c, and is implicitly
// called by DECL_LLVM if a decl doesn't have an LLVM set.
//
void make_decl_llvm(tree decl) {
#ifdef ENABLE_CHECKING
  // Check that we are not being given an automatic variable.
  // A weak alias has TREE_PUBLIC set but not the other bits.
  if (TREE_CODE(decl) == PARM_DECL || TREE_CODE(decl) == RESULT_DECL
      || (TREE_CODE(decl) == VAR_DECL && !TREE_STATIC(decl) &&
          !TREE_PUBLIC(decl) && !DECL_EXTERNAL(decl) && !DECL_REGISTER(decl)))
    abort();
  // And that we were not given a type or a label.  */
  else if (TREE_CODE(decl) == TYPE_DECL || TREE_CODE(decl) == LABEL_DECL)
    abort ();
#endif
  
  // For a duplicate declaration, we can be called twice on the
  // same DECL node.  Don't discard the LLVM already made.
  if (DECL_LLVM_SET_P(decl)) return;

  if (errorcount || sorrycount)
    return;  // Do not process broken code.
  
  
  // Global register variable with asm name, e.g.:
  // register unsigned long esp __asm__("ebp");
  if (TREE_CODE(decl) != FUNCTION_DECL && DECL_REGISTER(decl)) {
    // This  just verifies that the variable is ok.  The actual "load/store"
    // code paths handle accesses to the variable.
    ValidateRegisterVariable(decl);
    return;
  }
  
  timevar_push(TV_LLVM_GLOBALS);

  const char *Name = "";
  if (DECL_NAME(decl))
    if (tree AssemblerName = DECL_ASSEMBLER_NAME(decl))
      Name = IDENTIFIER_POINTER(AssemblerName);
  
  // Now handle ordinary static variables and functions (in memory).
  // Also handle vars declared register invalidly.
  if (Name[0] == 1) {
#ifdef REGISTER_PREFIX
    if (strlen (REGISTER_PREFIX) != 0) {
      int reg_number = decode_reg_name(Name);
      if (reg_number >= 0 || reg_number == -3)
        error("%Jregister name given for non-register variable %qD",
              decl, decl);
    }
#endif
  }
  
  // Specifying a section attribute on a variable forces it into a
  // non-.bss section, and thus it cannot be common.
  if (TREE_CODE(decl) == VAR_DECL && DECL_SECTION_NAME(decl) != NULL_TREE &&
      DECL_INITIAL(decl) == NULL_TREE && DECL_COMMON(decl))
    DECL_COMMON(decl) = 0;
  
  // Variables can't be both common and weak.
  if (TREE_CODE(decl) == VAR_DECL && DECL_WEAK(decl))
    DECL_COMMON(decl) = 0;
  
  // Okay, now we need to create an LLVM global variable or function for this
  // object.  Note that this is quite possibly a forward reference to the
  // object, so its type may change later.
  if (TREE_CODE(decl) == FUNCTION_DECL) {
    assert(Name[0] && "Function with empty name!");
    // If this function has already been created, reuse the decl.  This happens
    // when we have something like __builtin_memset and memset in the same file.
    Function *FnEntry = TheModule->getFunction(Name);
    if (FnEntry == 0) {
      unsigned CC;
      const FunctionType *Ty = 
        TheTypeConverter->ConvertFunctionType(TREE_TYPE(decl), decl, NULL, CC);
      FnEntry = new Function(Ty, Function::ExternalLinkage, Name, TheModule);
      FnEntry->setCallingConv(CC);

      // Check for external weak linkage
      if (DECL_EXTERNAL(decl) && DECL_WEAK(decl))
        FnEntry->setLinkage(Function::ExternalWeakLinkage);
      
#ifdef TARGET_ADJUST_LLVM_LINKAGE
      TARGET_ADJUST_LLVM_LINKAGE(FnEntry,decl);
#endif /* TARGET_ADJUST_LLVM_LINKAGE */

      // Handle visibility style
      if (TREE_PUBLIC(decl)) {
        if (DECL_VISIBILITY(decl) == VISIBILITY_HIDDEN)
          FnEntry->setVisibility(GlobalValue::HiddenVisibility);
        else if (DECL_VISIBILITY(decl) == VISIBILITY_PROTECTED)
          FnEntry->setVisibility(GlobalValue::ProtectedVisibility);
      }

      assert(FnEntry->getName() == Name &&"Preexisting fn with the same name!");
    }
    SET_DECL_LLVM(decl, FnEntry);
  } else {
    assert((TREE_CODE(decl) == VAR_DECL ||
            TREE_CODE(decl) == CONST_DECL) && "Not a function or var decl?");
    const Type *Ty = ConvertType(TREE_TYPE(decl));
    GlobalVariable *GV ;

    // If we have "extern void foo", make the global have type {} instead of
    // type void.
    if (Ty == Type::VoidTy) 
      Ty = StructType::get(std::vector<const Type*>(), false);
    
    if (Name[0] == 0) {   // Global has no name.
      GV = new GlobalVariable(Ty, false, GlobalValue::ExternalLinkage, 0,
                              "", TheModule);

      // Check for external weak linkage
      if (DECL_EXTERNAL(decl) && DECL_WEAK(decl))
        GV->setLinkage(GlobalValue::ExternalWeakLinkage);
      
#ifdef TARGET_ADJUST_LLVM_LINKAGE
      TARGET_ADJUST_LLVM_LINKAGE(GV,decl);
#endif /* TARGET_ADJUST_LLVM_LINKAGE */

      // Handle visibility style
      if (TREE_PUBLIC(decl)) {
        if (DECL_VISIBILITY(decl) == VISIBILITY_HIDDEN)
          GV->setVisibility(GlobalValue::HiddenVisibility);
        else if (DECL_VISIBILITY(decl) == VISIBILITY_PROTECTED)
          GV->setVisibility(GlobalValue::ProtectedVisibility);
      }

    } else {
      // If the global has a name, prevent multiple vars with the same name from
      // being created.
      GlobalVariable *GVE = TheModule->getGlobalVariable(Name);
    
      if (GVE == 0) {
        GV = new GlobalVariable(Ty, false, GlobalValue::ExternalLinkage,0,
                                Name, TheModule);

        // Check for external weak linkage
        if (DECL_EXTERNAL(decl) && DECL_WEAK(decl))
          GV->setLinkage(GlobalValue::ExternalWeakLinkage);
        
#ifdef TARGET_ADJUST_LLVM_LINKAGE
        TARGET_ADJUST_LLVM_LINKAGE(GV,decl);
#endif /* TARGET_ADJUST_LLVM_LINKAGE */

        // Handle visibility style
        if (TREE_PUBLIC(decl)) {
          if (DECL_VISIBILITY(decl) == VISIBILITY_HIDDEN)
            GV->setVisibility(GlobalValue::HiddenVisibility);
          else if (DECL_VISIBILITY(decl) == VISIBILITY_PROTECTED)
            GV->setVisibility(GlobalValue::ProtectedVisibility);
        }

        // If GV got renamed, then there is already an object with this name in
        // the symbol table.  If this happens, the old one must be a forward
        // decl, just replace it with a cast of the new one.
        if (GV->getName() != Name) {
          Function *F = TheModule->getFunction(Name);
          assert(F && F->isDeclaration() && "A function turned into a global?");
          
          // Replace any uses of "F" with uses of GV.
          Value *FInNewType = ConstantExpr::getBitCast(GV, F->getType());
          F->replaceAllUsesWith(FInNewType);
          
          // Update the decl that points to F.
          changeLLVMValue(F, FInNewType);

          // Now we can give GV the proper name.
          GV->takeName(F);
          
          // F is now dead, nuke it.
          F->eraseFromParent();
        }
        
      } else {
        GV = GVE;  // Global already created, reuse it.
      }
    }
    
    if ((TREE_READONLY(decl) && !TREE_SIDE_EFFECTS(decl)) || 
        TREE_CODE(decl) == CONST_DECL) {
      if (DECL_EXTERNAL(decl)) {
        // Mark external globals constant even though they could be marked
        // non-constant in the defining translation unit.  The definition of the
        // global determines whether the global is ultimately constant or not,
        // marking this constant will allow us to do some extra (legal)
        // optimizations that we would otherwise not be able to do.  (In C++,
        // any global that is 'C++ const' may not be readonly: it could have a
        // dynamic initializer.
        //
        GV->setConstant(true);
      } else {
        // Mark readonly globals with constant initializers constant.
        if (DECL_INITIAL(decl) != error_mark_node && // uninitialized?
            DECL_INITIAL(decl) &&
            (TREE_CONSTANT(DECL_INITIAL(decl)) ||
             TREE_CODE(DECL_INITIAL(decl)) == STRING_CST))
          GV->setConstant(true);
      }
    }

    // Set thread local (TLS)
    if (TREE_CODE(decl) == VAR_DECL && DECL_THREAD_LOCAL(decl))
      GV->setThreadLocal(true);

    SET_DECL_LLVM(decl, GV);
  }
  timevar_pop(TV_LLVM_GLOBALS);
}
Module *llvm::CloneModule(const Module *M,
                          ValueToValueMapTy &VMap) {
  // First off, we need to create the new module...
  Module *New = new Module(M->getModuleIdentifier(), M->getContext());
  New->setDataLayout(M->getDataLayout());
  New->setTargetTriple(M->getTargetTriple());
  New->setModuleInlineAsm(M->getModuleInlineAsm());

  // Copy all of the type symbol table entries over.
  const TypeSymbolTable &TST = M->getTypeSymbolTable();
  for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end(); 
       TI != TE; ++TI)
    New->addTypeName(TI->first, TI->second);
  
  // Copy all of the dependent libraries over.
  for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
    New->addLibrary(*I);

  // Loop over all of the global variables, making corresponding globals in the
  // new module.  Here we add them to the VMap and to the new Module.  We
  // don't worry about attributes or initializers, they will come later.
  //
  for (Module::const_global_iterator I = M->global_begin(), E = M->global_end();
       I != E; ++I) {
    GlobalVariable *GV = new GlobalVariable(*New, 
                                            I->getType()->getElementType(),
                                            false,
                                            GlobalValue::ExternalLinkage, 0,
                                            I->getName());
    GV->setAlignment(I->getAlignment());
    VMap[I] = GV;
  }

  // Loop over the functions in the module, making external functions as before
  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I) {
    Function *NF =
      Function::Create(cast<FunctionType>(I->getType()->getElementType()),
                       GlobalValue::ExternalLinkage, I->getName(), New);
    NF->copyAttributesFrom(I);
    VMap[I] = NF;
  }

  // Loop over the aliases in the module
  for (Module::const_alias_iterator I = M->alias_begin(), E = M->alias_end();
       I != E; ++I)
    VMap[I] = new GlobalAlias(I->getType(), GlobalAlias::ExternalLinkage,
                                  I->getName(), NULL, New);
  
  // Now that all of the things that global variable initializer can refer to
  // have been created, loop through and copy the global variable referrers
  // over...  We also set the attributes on the global now.
  //
  for (Module::const_global_iterator I = M->global_begin(), E = M->global_end();
       I != E; ++I) {
    GlobalVariable *GV = cast<GlobalVariable>(VMap[I]);
    if (I->hasInitializer())
      GV->setInitializer(cast<Constant>(MapValue(I->getInitializer(),
                                                 VMap)));
    GV->setLinkage(I->getLinkage());
    GV->setThreadLocal(I->isThreadLocal());
    GV->setConstant(I->isConstant());
  }

  // Similarly, copy over function bodies now...
  //
  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I) {
    Function *F = cast<Function>(VMap[I]);
    if (!I->isDeclaration()) {
      Function::arg_iterator DestI = F->arg_begin();
      for (Function::const_arg_iterator J = I->arg_begin(); J != I->arg_end();
           ++J) {
        DestI->setName(J->getName());
        VMap[J] = DestI++;
      }

      SmallVector<ReturnInst*, 8> Returns;  // Ignore returns cloned.
      CloneFunctionInto(F, I, VMap, Returns);
    }

    F->setLinkage(I->getLinkage());
  }

  // And aliases
  for (Module::const_alias_iterator I = M->alias_begin(), E = M->alias_end();
       I != E; ++I) {
    GlobalAlias *GA = cast<GlobalAlias>(VMap[I]);
    GA->setLinkage(I->getLinkage());
    if (const Constant* C = I->getAliasee())
      GA->setAliasee(cast<Constant>(MapValue(C, VMap)));
  }

  // And named metadata....
  for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
         E = M->named_metadata_end(); I != E; ++I) {
    const NamedMDNode &NMD = *I;
    SmallVector<MDNode*, 4> MDs;
    for (unsigned i = 0, e = NMD.getNumOperands(); i != e; ++i)
      MDs.push_back(cast<MDNode>(MapValue(NMD.getOperand(i), VMap)));
    NamedMDNode::Create(New->getContext(), NMD.getName(),
                        MDs.data(), MDs.size(), New);
  }

  // Update metadata attach with instructions.
  for (Module::iterator MI = New->begin(), ME = New->end(); MI != ME; ++MI)   
    for (Function::iterator FI = MI->begin(), FE = MI->end(); 
         FI != FE; ++FI)
      for (BasicBlock::iterator BI = FI->begin(), BE = FI->end(); 
           BI != BE; ++BI) {
        SmallVector<std::pair<unsigned, MDNode *>, 4 > MDs;
        BI->getAllMetadata(MDs);
        for (SmallVector<std::pair<unsigned, MDNode *>, 4>::iterator 
               MDI = MDs.begin(), MDE = MDs.end(); MDI != MDE; ++MDI) {
          Value *MappedValue = MapValue(MDI->second, VMap);
          if (MDI->second != MappedValue && MappedValue)
            BI->setMetadata(MDI->first, cast<MDNode>(MappedValue));
        }
      }
  return New;
}
/// emit_global_to_llvm - Emit the specified VAR_DECL or aggregate CONST_DECL to
/// LLVM as a global variable.  This function implements the end of
/// assemble_variable.
void emit_global_to_llvm(tree decl) {
  if (errorcount || sorrycount) return;

  // FIXME: Support alignment on globals: DECL_ALIGN.
  // FIXME: DECL_PRESERVE_P indicates the var is marked with attribute 'used'.

  // Global register variables don't turn into LLVM GlobalVariables.
  if (TREE_CODE(decl) == VAR_DECL && DECL_REGISTER(decl))
    return;

  timevar_push(TV_LLVM_GLOBALS);

  // Get or create the global variable now.
  GlobalVariable *GV = cast<GlobalVariable>(DECL_LLVM(decl));
  
  // Convert the initializer over.
  Constant *Init;
  if (DECL_INITIAL(decl) == 0 || DECL_INITIAL(decl) == error_mark_node) {
    // This global should be zero initialized.  Reconvert the type in case the
    // forward def of the global and the real def differ in type (e.g. declared
    // as 'int A[]', and defined as 'int A[100]').
    Init = Constant::getNullValue(ConvertType(TREE_TYPE(decl)));
  } else {
    assert((TREE_CONSTANT(DECL_INITIAL(decl)) || 
            TREE_CODE(DECL_INITIAL(decl)) == STRING_CST) &&
           "Global initializer should be constant!");
    
    // Temporarily set an initializer for the global, so we don't infinitely
    // recurse.  If we don't do this, we can hit cases where we see "oh a global
    // with an initializer hasn't been initialized yet, call emit_global_to_llvm
    // on it".  When constructing the initializer it might refer to itself.
    // this can happen for things like void *G = &G;
    //
    GV->setInitializer(UndefValue::get(GV->getType()->getElementType()));
    Init = TreeConstantToLLVM::Convert(DECL_INITIAL(decl));
  }

  // If we had a forward definition that has a type that disagrees with our
  // initializer, insert a cast now.  This sort of thing occurs when we have a
  // global union, and the LLVM type followed a union initializer that is
  // different from the union element used for the type.
  if (GV->getType()->getElementType() != Init->getType()) {
    GV->removeFromParent();
    GlobalVariable *NGV = new GlobalVariable(Init->getType(), GV->isConstant(),
                                             GlobalValue::ExternalLinkage, 0,
                                             GV->getName(), TheModule);
    GV->replaceAllUsesWith(ConstantExpr::getBitCast(NGV, GV->getType()));
    delete GV;
    SET_DECL_LLVM(decl, NGV);
    GV = NGV;
  }
 
  // Set the initializer.
  GV->setInitializer(Init);

  // Set thread local (TLS)
  if (TREE_CODE(decl) == VAR_DECL && DECL_THREAD_LOCAL(decl))
    GV->setThreadLocal(true);

  // Set the linkage.
  if (!TREE_PUBLIC(decl)) {
    GV->setLinkage(GlobalValue::InternalLinkage);
  } else if (DECL_WEAK(decl) || DECL_ONE_ONLY(decl) ||
             (DECL_COMMON(decl) &&  // DECL_COMMON is only meaningful if no init
              (!DECL_INITIAL(decl) || DECL_INITIAL(decl) == error_mark_node))) {
    // llvm-gcc also includes DECL_VIRTUAL_P here.
    GV->setLinkage(GlobalValue::WeakLinkage);
  } else if (DECL_COMDAT(decl)) {
    GV->setLinkage(GlobalValue::LinkOnceLinkage);
  }

#ifdef TARGET_ADJUST_LLVM_LINKAGE
  TARGET_ADJUST_LLVM_LINKAGE(GV,decl);
#endif /* TARGET_ADJUST_LLVM_LINKAGE */

  // Handle visibility style
  if (TREE_PUBLIC(decl)) {
    if (DECL_VISIBILITY(decl) == VISIBILITY_HIDDEN)
      GV->setVisibility(GlobalValue::HiddenVisibility);
    else if (DECL_VISIBILITY(decl) == VISIBILITY_PROTECTED)
      GV->setVisibility(GlobalValue::ProtectedVisibility);
  }

  // Set the section for the global.
  if (TREE_CODE(decl) == VAR_DECL || TREE_CODE(decl) == CONST_DECL) {
    if (DECL_SECTION_NAME(decl)) {
      GV->setSection(TREE_STRING_POINTER(DECL_SECTION_NAME(decl)));
#ifdef LLVM_IMPLICIT_TARGET_GLOBAL_VAR_SECTION
    } else if (const char *Section = 
                LLVM_IMPLICIT_TARGET_GLOBAL_VAR_SECTION(decl)) {
      GV->setSection(Section);
#endif
    }
    
    // Set the alignment for the global if one of the following condition is met
    // 1) DECL_ALIGN_UNIT does not match alignment as per ABI specification
    // 2) DECL_ALIGN is set by user.
    if (DECL_ALIGN_UNIT(decl)) {
      unsigned TargetAlign = getTargetData().getABITypeAlignment(GV->getType()->getElementType());
      if (DECL_USER_ALIGN(decl) || TargetAlign != DECL_ALIGN_UNIT(decl))
        GV->setAlignment(DECL_ALIGN_UNIT(decl));
    }

    // Handle used decls
    if (DECL_PRESERVE_P (decl)) {
      const Type *SBP= PointerType::get(Type::Int8Ty);
      AttributeUsedGlobals.push_back(ConstantExpr::getBitCast(GV, SBP));
    }
  
    // Add annotate attributes for globals
    if (DECL_ATTRIBUTES(decl))
      AddAnnotateAttrsToGlobal(GV, decl);
  }
  
  if (TheDebugInfo) TheDebugInfo->EmitGlobalVariable(GV, decl); 
  
  timevar_pop(TV_LLVM_GLOBALS);
}