llvm/lib/VMCore/Module.cpp

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//===-- Module.cpp - Implement the Module class ---------------------------===//
//
// 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.
//
//===----------------------------------------------------------------------===//
//
// This file implements the Module class for the VMCore library.
//
//===----------------------------------------------------------------------===//
#include "llvm/Module.h"
#include "llvm/InstrTypes.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "Support/STLExtras.h"
#include "Support/LeakDetector.h"
#include "SymbolTableListTraitsImpl.h"
#include <algorithm>
#include <cstdarg>
#include <map>
using namespace llvm;
//===----------------------------------------------------------------------===//
// Stuff to implement the globals and functions lists.
//
Function *ilist_traits<Function>::createNode() {
FunctionType *FTy =
FunctionType::get(Type::VoidTy, std::vector<const Type*>(), false);
Function *Ret = new Function(FTy, GlobalValue::ExternalLinkage);
// This should not be garbage monitored.
LeakDetector::removeGarbageObject(Ret);
return Ret;
}
GlobalVariable *ilist_traits<GlobalVariable>::createNode() {
GlobalVariable *Ret = new GlobalVariable(Type::IntTy, false,
GlobalValue::ExternalLinkage);
// This should not be garbage monitored.
LeakDetector::removeGarbageObject(Ret);
return Ret;
}
iplist<Function> &ilist_traits<Function>::getList(Module *M) {
return M->getFunctionList();
}
iplist<GlobalVariable> &ilist_traits<GlobalVariable>::getList(Module *M) {
return M->getGlobalList();
}
// Explicit instantiations of SymbolTableListTraits since some of the methods
// are not in the public header file...
template class SymbolTableListTraits<GlobalVariable, Module, Module>;
template class SymbolTableListTraits<Function, Module, Module>;
// Define the GlobalValueRefMap as a struct that wraps a map so that we don't
// have Module.h depend on <map>
//
namespace llvm {
struct GlobalValueRefMap {
typedef std::map<GlobalValue*, ConstantPointerRef*> MapTy;
typedef MapTy::iterator iterator;
std::map<GlobalValue*, ConstantPointerRef*> Map;
};
}
//===----------------------------------------------------------------------===//
// Primitive Module methods.
//
Module::Module(const std::string &MID)
: ModuleID(MID), Endian(AnyEndianness), PtrSize(AnyPointerSize) {
FunctionList.setItemParent(this);
FunctionList.setParent(this);
GlobalList.setItemParent(this);
GlobalList.setParent(this);
GVRefMap = 0;
SymTab = new SymbolTable();
}
Module::~Module() {
dropAllReferences();
GlobalList.clear();
GlobalList.setParent(0);
FunctionList.clear();
FunctionList.setParent(0);
delete SymTab;
}
// Module::dump() - Allow printing from debugger
void Module::dump() const {
print(std::cerr);
}
//===----------------------------------------------------------------------===//
// Methods for easy access to the functions in the module.
//
// getOrInsertFunction - Look up the specified function in the module symbol
// table. If it does not exist, add a prototype for the function and return
// it. This is nice because it allows most passes to get away with not handling
// the symbol table directly for this common task.
//
Function *Module::getOrInsertFunction(const std::string &Name,
const FunctionType *Ty) {
SymbolTable &SymTab = getSymbolTable();
// See if we have a definitions for the specified function already...
if (Value *V = SymTab.lookup(PointerType::get(Ty), Name)) {
return cast<Function>(V); // Yup, got it
} else { // Nope, add one
Function *New = new Function(Ty, GlobalVariable::ExternalLinkage, Name);
FunctionList.push_back(New);
return New; // Return the new prototype...
}
}
// getOrInsertFunction - Look up the specified function in the module symbol
// table. If it does not exist, add a prototype for the function and return it.
// This version of the method takes a null terminated list of function
// arguments, which makes it easier for clients to use.
//
Function *Module::getOrInsertFunction(const std::string &Name,
const Type *RetTy, ...) {
va_list Args;
va_start(Args, RetTy);
// Build the list of argument types...
std::vector<const Type*> ArgTys;
while (const Type *ArgTy = va_arg(Args, const Type*))
ArgTys.push_back(ArgTy);
va_end(Args);
// Build the function type and chain to the other getOrInsertFunction...
return getOrInsertFunction(Name, FunctionType::get(RetTy, ArgTys, false));
}
// getFunction - Look up the specified function in the module symbol table.
// If it does not exist, return null.
//
Function *Module::getFunction(const std::string &Name, const FunctionType *Ty) {
SymbolTable &SymTab = getSymbolTable();
return cast_or_null<Function>(SymTab.lookup(PointerType::get(Ty), Name));
}
/// getMainFunction - This function looks up main efficiently. This is such a
/// common case, that it is a method in Module. If main cannot be found, a
/// null pointer is returned.
///
Function *Module::getMainFunction() {
std::vector<const Type*> Params;
// int main(void)...
if (Function *F = getFunction("main", FunctionType::get(Type::IntTy,
Params, false)))
return F;
// void main(void)...
if (Function *F = getFunction("main", FunctionType::get(Type::VoidTy,
Params, false)))
return F;
Params.push_back(Type::IntTy);
// int main(int argc)...
if (Function *F = getFunction("main", FunctionType::get(Type::IntTy,
Params, false)))
return F;
// void main(int argc)...
if (Function *F = getFunction("main", FunctionType::get(Type::VoidTy,
Params, false)))
return F;
for (unsigned i = 0; i != 2; ++i) { // Check argv and envp
Params.push_back(PointerType::get(PointerType::get(Type::SByteTy)));
// int main(int argc, char **argv)...
if (Function *F = getFunction("main", FunctionType::get(Type::IntTy,
Params, false)))
return F;
// void main(int argc, char **argv)...
if (Function *F = getFunction("main", FunctionType::get(Type::VoidTy,
Params, false)))
return F;
}
// Ok, try to find main the hard way...
return getNamedFunction("main");
}
/// getNamedFunction - Return the first function in the module with the
/// specified name, of arbitrary type. This method returns null if a function
/// with the specified name is not found.
///
Function *Module::getNamedFunction(const std::string &Name) {
// Loop over all of the functions, looking for the function desired
Function *Found = 0;
for (iterator I = begin(), E = end(); I != E; ++I)
if (I->getName() == Name)
if (I->isExternal())
Found = I;
else
return I;
return Found; // Non-external function not found...
}
//===----------------------------------------------------------------------===//
// Methods for easy access to the global variables in the module.
//
/// getGlobalVariable - Look up the specified global variable in the module
/// symbol table. If it does not exist, return null. Note that this only
/// returns a global variable if it does not have internal linkage. The type
/// argument should be the underlying type of the global, ie, it should not
/// have the top-level PointerType, which represents the address of the
/// global.
///
GlobalVariable *Module::getGlobalVariable(const std::string &Name,
const Type *Ty) {
if (Value *V = getSymbolTable().lookup(PointerType::get(Ty), Name)) {
GlobalVariable *Result = cast<GlobalVariable>(V);
if (!Result->hasInternalLinkage())
return Result;
}
return 0;
}
//===----------------------------------------------------------------------===//
// Methods for easy access to the types in the module.
//
// addTypeName - Insert an entry in the symbol table mapping Str to Type. If
// there is already an entry for this name, true is returned and the symbol
// table is not modified.
//
bool Module::addTypeName(const std::string &Name, const Type *Ty) {
SymbolTable &ST = getSymbolTable();
if (ST.lookup(Type::TypeTy, Name)) return true; // Already in symtab...
// Not in symbol table? Set the name with the Symtab as an argument so the
// type knows what to update...
((Value*)Ty)->setName(Name, &ST);
return false;
}
/// getTypeByName - Return the type with the specified name in this module, or
/// null if there is none by that name.
const Type *Module::getTypeByName(const std::string &Name) const {
const SymbolTable &ST = getSymbolTable();
return cast_or_null<Type>(ST.lookup(Type::TypeTy, Name));
}
// getTypeName - If there is at least one entry in the symbol table for the
// specified type, return it.
//
std::string Module::getTypeName(const Type *Ty) const {
const SymbolTable &ST = getSymbolTable();
if (ST.find(Type::TypeTy) == ST.end())
return ""; // No names for types...
SymbolTable::type_const_iterator TI = ST.type_begin(Type::TypeTy);
SymbolTable::type_const_iterator TE = ST.type_end(Type::TypeTy);
while (TI != TE && TI->second != (const Value*)Ty)
++TI;
if (TI != TE) // Must have found an entry!
return TI->first;
return ""; // Must not have found anything...
}
//===----------------------------------------------------------------------===//
// Other module related stuff.
//
// dropAllReferences() - This function causes all the subelementss to "let go"
// of all references that they are maintaining. This allows one to 'delete' a
// whole module at a time, even though there may be circular references... first
// all references are dropped, and all use counts go to zero. Then everything
// is deleted for real. Note that no operations are valid on an object that
// has "dropped all references", except operator delete.
//
void Module::dropAllReferences() {
for(Module::iterator I = begin(), E = end(); I != E; ++I)
I->dropAllReferences();
for(Module::giterator I = gbegin(), E = gend(); I != E; ++I)
I->dropAllReferences();
// If there are any GlobalVariable references still out there, nuke them now.
// Since all references are hereby dropped, nothing could possibly reference
// them still. Note that destroying all of the constant pointer refs will
// eventually cause the GVRefMap field to be set to null (by
// destroyConstantPointerRef, below).
//
while (GVRefMap)
// Delete the ConstantPointerRef node...
GVRefMap->Map.begin()->second->destroyConstant();
}
// Accessor for the underlying GlobalValRefMap...
ConstantPointerRef *Module::getConstantPointerRef(GlobalValue *V){
// Create ref map lazily on demand...
if (GVRefMap == 0) GVRefMap = new GlobalValueRefMap();
GlobalValueRefMap::iterator I = GVRefMap->Map.find(V);
if (I != GVRefMap->Map.end()) return I->second;
ConstantPointerRef *Ref = new ConstantPointerRef(V);
GVRefMap->Map[V] = Ref;
return Ref;
}
void Module::destroyConstantPointerRef(ConstantPointerRef *CPR) {
assert(GVRefMap && "No map allocated, but we have a CPR?");
if (!GVRefMap->Map.erase(CPR->getValue())) // Remove it from the map...
assert(0 && "ConstantPointerRef not found in module CPR map!");
if (GVRefMap->Map.empty()) { // If the map is empty, delete it.
delete GVRefMap;
GVRefMap = 0;
}
}
void Module::mutateConstantPointerRef(GlobalValue *OldGV, GlobalValue *NewGV) {
assert(OldGV != NewGV && "Cannot mutate to the same global!");
GlobalValueRefMap::iterator I = GVRefMap->Map.find(OldGV);
assert(I != GVRefMap->Map.end() &&
"mutateConstantPointerRef; OldGV not in table!");
ConstantPointerRef *Ref = I->second;
// Remove the old entry...
GVRefMap->Map.erase(I);
// Check to see if a CPR already exists for NewGV
I = GVRefMap->Map.lower_bound(NewGV);
if (I == GVRefMap->Map.end() || I->first != NewGV) {
// Insert the new entry...
GVRefMap->Map.insert(I, std::make_pair(NewGV, Ref));
} else {
// Otherwise, an entry already exists for the current global value.
// Completely replace the old CPR with the existing one...
Ref->replaceAllUsesWith(I->second);
delete Ref;
}
}