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/CallSite.h" 21#include "llvm/IR/Module.h" 22#include "llvm/Pass.h" 23#include "llvm/Support/raw_ostream.h" 24using namespace llvm; 25 26namespace { 27 /// ExternalFunctionsPassedConstants - This pass prints out call sites to 28 /// external functions that are called with constant arguments. This can be 29 /// useful when looking for standard library functions we should constant fold 30 /// or handle in alias analyses. 31 struct ExternalFunctionsPassedConstants : public ModulePass { 32 static char ID; // Pass ID, replacement for typeid 33 ExternalFunctionsPassedConstants() : ModulePass(ID) {} 34 bool runOnModule(Module &M) override { 35 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) { 36 if (!I->isDeclaration()) continue; 37 38 bool PrintedFn = false; 39 for (User *U : I->users()) { 40 Instruction *UI = dyn_cast<Instruction>(U); 41 if (!UI) continue; 42 43 CallSite CS(cast<Value>(UI)); 44 if (!CS) continue; 45 46 for (CallSite::arg_iterator AI = CS.arg_begin(), 47 E = CS.arg_end(); AI != E; ++AI) { 48 if (!isa<Constant>(*AI)) continue; 49 50 if (!PrintedFn) { 51 errs() << "Function '" << I->getName() << "':\n"; 52 PrintedFn = true; 53 } 54 errs() << *UI; 55 break; 56 } 57 } 58 } 59 60 return false; 61 } 62 63 void getAnalysisUsage(AnalysisUsage &AU) const override { 64 AU.setPreservesAll(); 65 } 66 }; 67} 68 69char ExternalFunctionsPassedConstants::ID = 0; 70static RegisterPass<ExternalFunctionsPassedConstants> 71 P1("print-externalfnconstants", 72 "Print external fn callsites passed constants"); 73