1//===- AnalysisWrappers.cpp - Wrappers around non-pass analyses -----------===// 2// 3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4// See https://llvm.org/LICENSE.txt for license information. 5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6// 7//===----------------------------------------------------------------------===// 8// 9// This file defines pass wrappers around LLVM analyses that don't make sense to 10// be passes. It provides a nice standard pass interface to these classes so 11// that they can be printed out by analyze. 12// 13// These classes are separated out of analyze.cpp so that it is more clear which 14// code is the integral part of the analyze tool, and which part of the code is 15// just making it so more passes are available. 16// 17//===----------------------------------------------------------------------===// 18 19#include "llvm/Analysis/CallGraph.h" 20#include "llvm/IR/Module.h" 21#include "llvm/Pass.h" 22#include "llvm/Support/raw_ostream.h" 23using namespace llvm; 24 25namespace { 26 /// ExternalFunctionsPassedConstants - This pass prints out call sites to 27 /// external functions that are called with constant arguments. This can be 28 /// useful when looking for standard library functions we should constant fold 29 /// or handle in alias analyses. 30 struct ExternalFunctionsPassedConstants : public ModulePass { 31 static char ID; // Pass ID, replacement for typeid 32 ExternalFunctionsPassedConstants() : ModulePass(ID) {} 33 bool runOnModule(Module &M) override { 34 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) { 35 if (!I->isDeclaration()) continue; 36 37 bool PrintedFn = false; 38 for (User *U : I->users()) { 39 Instruction *UI = dyn_cast<Instruction>(U); 40 if (!UI) continue; 41 42 CallBase *CB = dyn_cast<CallBase>(UI); 43 if (!CB) 44 continue; 45 46 for (auto AI = CB->arg_begin(), E = CB->arg_end(); AI != E; ++AI) { 47 if (!isa<Constant>(*AI)) continue; 48 49 if (!PrintedFn) { 50 errs() << "Function '" << I->getName() << "':\n"; 51 PrintedFn = true; 52 } 53 errs() << *UI; 54 break; 55 } 56 } 57 } 58 59 return false; 60 } 61 62 void getAnalysisUsage(AnalysisUsage &AU) const override { 63 AU.setPreservesAll(); 64 } 65 }; 66} 67 68char ExternalFunctionsPassedConstants::ID = 0; 69static RegisterPass<ExternalFunctionsPassedConstants> 70 P1("print-externalfnconstants", 71 "Print external fn callsites passed constants"); 72