llvm-project/llvm/tools/opt/AnalysisWrappers.cpp

73 lines
2.5 KiB
C++

//===- AnalysisWrappers.cpp - Wrappers around non-pass analyses -----------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines pass wrappers around LLVM analyses that don't make sense to
// be passes. It provides a nice standard pass interface to these classes so
// that they can be printed out by analyze.
//
// These classes are separated out of analyze.cpp so that it is more clear which
// code is the integral part of the analyze tool, and which part of the code is
// just making it so more passes are available.
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/CallGraph.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/Module.h"
#include "llvm/Pass.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
namespace {
/// ExternalFunctionsPassedConstants - This pass prints out call sites to
/// external functions that are called with constant arguments. This can be
/// useful when looking for standard library functions we should constant fold
/// or handle in alias analyses.
struct ExternalFunctionsPassedConstants : public ModulePass {
static char ID; // Pass ID, replacement for typeid
ExternalFunctionsPassedConstants() : ModulePass(ID) {}
bool runOnModule(Module &M) override {
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
if (!I->isDeclaration()) continue;
bool PrintedFn = false;
for (User *U : I->users()) {
Instruction *UI = dyn_cast<Instruction>(U);
if (!UI) continue;
CallSite CS(cast<Value>(UI));
if (!CS) continue;
for (CallSite::arg_iterator AI = CS.arg_begin(),
E = CS.arg_end(); AI != E; ++AI) {
if (!isa<Constant>(*AI)) continue;
if (!PrintedFn) {
errs() << "Function '" << I->getName() << "':\n";
PrintedFn = true;
}
errs() << *UI;
break;
}
}
}
return false;
}
void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.setPreservesAll();
}
};
}
char ExternalFunctionsPassedConstants::ID = 0;
static RegisterPass<ExternalFunctionsPassedConstants>
P1("print-externalfnconstants",
"Print external fn callsites passed constants");