diff options
| -rw-r--r-- | lib/Transforms/IPO/FunctionResolution.cpp | 363 |
1 files changed, 0 insertions, 363 deletions
diff --git a/lib/Transforms/IPO/FunctionResolution.cpp b/lib/Transforms/IPO/FunctionResolution.cpp deleted file mode 100644 index 21f4a95..0000000 --- a/lib/Transforms/IPO/FunctionResolution.cpp +++ /dev/null @@ -1,363 +0,0 @@ -//===- FunctionResolution.cpp - Resolve declarations to implementations ---===// -// -// The LLVM Compiler Infrastructure -// -// This file was developed by the LLVM research group and is distributed under -// the University of Illinois Open Source License. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// -// -// Loop over the functions that are in the module and look for functions that -// have the same name. More often than not, there will be things like: -// -// declare void %foo(...) -// void %foo(int, int) { ... } -// -// because of the way things are declared in C. If this is the case, patch -// things up. -// -//===----------------------------------------------------------------------===// - -#define DEBUG_TYPE "funcresolve" -#include "llvm/Transforms/IPO.h" -#include "llvm/Module.h" -#include "llvm/DerivedTypes.h" -#include "llvm/Pass.h" -#include "llvm/Instructions.h" -#include "llvm/Constants.h" -#include "llvm/Support/CallSite.h" -#include "llvm/Target/TargetData.h" -#include "llvm/Assembly/Writer.h" -#include "llvm/ADT/Statistic.h" -#include <algorithm> -using namespace llvm; - -STATISTIC(NumResolved, "Number of varargs functions resolved"); -STATISTIC(NumGlobals, "Number of global variables resolved"); - -namespace { - struct FunctionResolvingPass : public ModulePass { - virtual void getAnalysisUsage(AnalysisUsage &AU) const { - AU.addRequired<TargetData>(); - } - - bool runOnModule(Module &M); - }; - RegisterPass<FunctionResolvingPass> X("funcresolve", "Resolve Functions"); -} - -ModulePass *llvm::createFunctionResolvingPass() { - return new FunctionResolvingPass(); -} - -static bool ResolveFunctions(Module &M, std::vector<GlobalValue*> &Globals, - Function *Concrete) { - bool Changed = false; - for (unsigned i = 0; i != Globals.size(); ++i) - if (Globals[i] != Concrete) { - Function *Old = cast<Function>(Globals[i]); - const FunctionType *OldFT = Old->getFunctionType(); - const FunctionType *ConcreteFT = Concrete->getFunctionType(); - - if (OldFT->getNumParams() > ConcreteFT->getNumParams() && - !ConcreteFT->isVarArg()) - if (!Old->use_empty()) { - cerr << "WARNING: Linking function '" << Old->getName() - << "' is causing arguments to be dropped.\n"; - cerr << "WARNING: Prototype: "; - WriteAsOperand(*cerr.stream(), Old); - cerr << " resolved to "; - WriteAsOperand(*cerr.stream(), Concrete); - cerr << "\n"; - } - - // Check to make sure that if there are specified types, that they - // match... - // - unsigned NumArguments = std::min(OldFT->getNumParams(), - ConcreteFT->getNumParams()); - - if (!Old->use_empty() && !Concrete->use_empty()) - for (unsigned i = 0; i < NumArguments; ++i) - if (OldFT->getParamType(i) != ConcreteFT->getParamType(i)) - if (OldFT->getParamType(i)->getTypeID() != - ConcreteFT->getParamType(i)->getTypeID()) { - cerr << "WARNING: Function [" << Old->getName() - << "]: Parameter types conflict for: '"; - WriteTypeSymbolic(*cerr.stream(), OldFT, &M); - cerr << "' (in " - << Old->getParent()->getModuleIdentifier() << ") and '"; - WriteTypeSymbolic(*cerr.stream(), ConcreteFT, &M); - cerr << "'(in " - << Concrete->getParent()->getModuleIdentifier() << ")\n"; - return Changed; - } - - // Attempt to convert all of the uses of the old function to the concrete - // form of the function. If there is a use of the fn that we don't - // understand here we punt to avoid making a bad transformation. - // - // At this point, we know that the return values are the same for our two - // functions and that the Old function has no varargs fns specified. In - // otherwords it's just <retty> (...) - // - if (!Old->use_empty()) { - Value *Replacement = Concrete; - if (Concrete->getType() != Old->getType()) - Replacement = ConstantExpr::getBitCast(Concrete, Old->getType()); - NumResolved += Old->getNumUses(); - Old->replaceAllUsesWith(Replacement); - } - - // Since there are no uses of Old anymore, remove it from the module. - M.getFunctionList().erase(Old); - } - return Changed; -} - - -static bool ResolveGlobalVariables(Module &M, - std::vector<GlobalValue*> &Globals, - GlobalVariable *Concrete) { - bool Changed = false; - - for (unsigned i = 0; i != Globals.size(); ++i) - if (Globals[i] != Concrete) { - Constant *Cast = ConstantExpr::getBitCast(Concrete,Globals[i]->getType()); - Globals[i]->replaceAllUsesWith(Cast); - - // Since there are no uses of Old anymore, remove it from the module. - M.getGlobalList().erase(cast<GlobalVariable>(Globals[i])); - - ++NumGlobals; - Changed = true; - } - return Changed; -} - -// Check to see if all of the callers of F ignore the return value. -static bool CallersAllIgnoreReturnValue(Function &F) { - if (F.getReturnType() == Type::VoidTy) return true; - for (Value::use_iterator I = F.use_begin(), E = F.use_end(); I != E; ++I) { - if (GlobalValue *GV = dyn_cast<GlobalValue>(*I)) { - for (Value::use_iterator I = GV->use_begin(), E = GV->use_end(); - I != E; ++I) { - CallSite CS = CallSite::get(*I); - if (!CS.getInstruction() || !CS.getInstruction()->use_empty()) - return false; - } - } else { - CallSite CS = CallSite::get(*I); - if (!CS.getInstruction() || !CS.getInstruction()->use_empty()) - return false; - } - } - return true; -} - -static bool ProcessGlobalsWithSameName(Module &M, TargetData &TD, - std::vector<GlobalValue*> &Globals) { - assert(!Globals.empty() && "Globals list shouldn't be empty here!"); - - bool isFunction = isa<Function>(Globals[0]); // Is this group all functions? - GlobalValue *Concrete = 0; // The most concrete implementation to resolve to - - for (unsigned i = 0; i != Globals.size(); ) { - if (isa<Function>(Globals[i]) != isFunction) { - cerr << "WARNING: Found function and global variable with the " - << "same name: '" << Globals[i]->getName() << "'.\n"; - return false; // Don't know how to handle this, bail out! - } - - if (isFunction) { - // For functions, we look to merge functions definitions of "int (...)" - // to 'int (int)' or 'int ()' or whatever else is not completely generic. - // - Function *F = cast<Function>(Globals[i]); - if (!F->isDeclaration()) { - if (Concrete && !Concrete->isDeclaration()) - return false; // Found two different functions types. Can't choose! - - Concrete = Globals[i]; - } else if (Concrete) { - if (Concrete->isDeclaration()) // If we have multiple external symbols... - if (F->getFunctionType()->getNumParams() > - cast<Function>(Concrete)->getFunctionType()->getNumParams()) - Concrete = F; // We are more concrete than "Concrete"! - - } else { - Concrete = F; - } - } else { - GlobalVariable *GV = cast<GlobalVariable>(Globals[i]); - if (!GV->isDeclaration()) { - if (Concrete) { - cerr << "WARNING: Two global variables with external linkage" - << " exist with the same name: '" << GV->getName() - << "'!\n"; - return false; - } - Concrete = GV; - } - } - ++i; - } - - if (Globals.size() > 1) { // Found a multiply defined global... - // If there are no external declarations, and there is at most one - // externally visible instance of the global, then there is nothing to do. - // - bool HasExternal = false; - unsigned NumInstancesWithExternalLinkage = 0; - - for (unsigned i = 0, e = Globals.size(); i != e; ++i) { - if (Globals[i]->isDeclaration()) - HasExternal = true; - else if (!Globals[i]->hasInternalLinkage()) - NumInstancesWithExternalLinkage++; - } - - if (!HasExternal && NumInstancesWithExternalLinkage <= 1) - return false; // Nothing to do? Must have multiple internal definitions. - - // There are a couple of special cases we don't want to print the warning - // for, check them now. - bool DontPrintWarning = false; - if (Concrete && Globals.size() == 2) { - GlobalValue *Other = Globals[Globals[0] == Concrete]; - // If the non-concrete global is a function which takes (...) arguments, - // and the return values match (or was never used), do not warn. - if (Function *ConcreteF = dyn_cast<Function>(Concrete)) - if (Function *OtherF = dyn_cast<Function>(Other)) - if ((ConcreteF->getReturnType() == OtherF->getReturnType() || - CallersAllIgnoreReturnValue(*OtherF)) && - OtherF->getFunctionType()->isVarArg() && - OtherF->getFunctionType()->getNumParams() == 0) - DontPrintWarning = true; - - // Otherwise, if the non-concrete global is a global array variable with a - // size of 0, and the concrete global is an array with a real size, don't - // warn. This occurs due to declaring 'extern int A[];'. - if (GlobalVariable *ConcreteGV = dyn_cast<GlobalVariable>(Concrete)) - if (GlobalVariable *OtherGV = dyn_cast<GlobalVariable>(Other)) { - const Type *CTy = ConcreteGV->getType(); - const Type *OTy = OtherGV->getType(); - - if (CTy->isSized()) - if (!OTy->isSized() || !TD.getTypeSize(OTy) || - TD.getTypeSize(OTy) == TD.getTypeSize(CTy)) - DontPrintWarning = true; - } - } - - if (0 && !DontPrintWarning) { - cerr << "WARNING: Found global types that are not compatible:\n"; - for (unsigned i = 0; i < Globals.size(); ++i) { - cerr << "\t"; - WriteTypeSymbolic(*cerr.stream(), Globals[i]->getType(), &M); - cerr << " %" << Globals[i]->getName() << "\n"; - } - } - - if (!Concrete) - Concrete = Globals[0]; - else if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Concrete)) { - // Handle special case hack to change globals if it will make their types - // happier in the long run. The situation we do this is intentionally - // extremely limited. - if (GV->use_empty() && GV->hasInitializer() && - GV->getInitializer()->isNullValue()) { - // Check to see if there is another (external) global with the same size - // and a non-empty use-list. If so, we will make IT be the real - // implementation. - unsigned TS = TD.getTypeSize(Concrete->getType()->getElementType()); - for (unsigned i = 0, e = Globals.size(); i != e; ++i) - if (Globals[i] != Concrete && !Globals[i]->use_empty() && - isa<GlobalVariable>(Globals[i]) && - TD.getTypeSize(Globals[i]->getType()->getElementType()) == TS) { - // At this point we want to replace Concrete with Globals[i]. Make - // concrete external, and Globals[i] have an initializer. - GlobalVariable *NGV = cast<GlobalVariable>(Globals[i]); - const Type *ElTy = NGV->getType()->getElementType(); - NGV->setInitializer(Constant::getNullValue(ElTy)); - cast<GlobalVariable>(Concrete)->setInitializer(0); - Concrete = NGV; - break; - } - } - } - - if (isFunction) - return ResolveFunctions(M, Globals, cast<Function>(Concrete)); - else - return ResolveGlobalVariables(M, Globals, - cast<GlobalVariable>(Concrete)); - } - return false; -} - -bool FunctionResolvingPass::runOnModule(Module &M) { - std::map<std::string, std::vector<GlobalValue*> > Globals; - - // Loop over the globals, adding them to the Globals map. We use a two pass - // algorithm here to avoid problems with iterators getting invalidated if we - // did a one pass scheme. - // - bool Changed = false; - for (Module::iterator I = M.begin(), E = M.end(); I != E; ) { - Function *F = I++; - if (F->use_empty() && F->isDeclaration()) { - M.getFunctionList().erase(F); - Changed = true; - } else if (!F->hasInternalLinkage() && !F->getName().empty() && - !F->getIntrinsicID()) - Globals[F->getName()].push_back(F); - } - - for (Module::global_iterator I = M.global_begin(), E = M.global_end(); - I != E; ) { - GlobalVariable *GV = I++; - if (GV->use_empty() && GV->isDeclaration()) { - M.getGlobalList().erase(GV); - Changed = true; - } else if (!GV->hasInternalLinkage() && !GV->getName().empty()) - Globals[GV->getName()].push_back(GV); - } - - TargetData &TD = getAnalysis<TargetData>(); - - // Now we have a list of all functions with a particular name. If there is - // more than one entry in a list, merge the functions together. - // - for (std::map<std::string, std::vector<GlobalValue*> >::iterator - I = Globals.begin(), E = Globals.end(); I != E; ++I) - Changed |= ProcessGlobalsWithSameName(M, TD, I->second); - - // Now loop over all of the globals, checking to see if any are trivially - // dead. If so, remove them now. - - for (Module::iterator I = M.begin(), E = M.end(); I != E; ) - if (I->isDeclaration() && I->use_empty()) { - Function *F = I; - ++I; - M.getFunctionList().erase(F); - ++NumResolved; - Changed = true; - } else { - ++I; - } - - for (Module::global_iterator I = M.global_begin(), E = M.global_end(); - I != E; ) - if (I->isDeclaration() && I->use_empty()) { - GlobalVariable *GV = I; - ++I; - M.getGlobalList().erase(GV); - ++NumGlobals; - Changed = true; - } else { - ++I; - } - - return Changed; -} |