+
+// 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");