tools/opt/AnalysisWrappers.cpp

   1 //===- AnalysisWrappers.cpp - Wrappers around non-pass analyses -----------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file defines pass wrappers around LLVM analyses that don't make sense to
  11 // be passes.  It provides a nice standard pass interface to these classes so
  12 // that they can be printed out by analyze.
  13 //
  14 // These classes are separated out of analyze.cpp so that it is more clear which
  15 // code is the integral part of the analyze tool, and which part of the code is
  16 // just making it so more passes are available.
  17 //
  18 //===----------------------------------------------------------------------===//
  19
  20 #include "llvm/Module.h"
  21 #include "llvm/Pass.h"
  22 #include "llvm/Support/CallSite.h"
  23 #include "llvm/Analysis/CallGraph.h"
  24 #include "llvm/Support/raw_ostream.h"
  25 #include <iostream>
  26 using namespace llvm;
  27
  28 namespace {
  29   /// ExternalFunctionsPassedConstants - This pass prints out call sites to
  30   /// external functions that are called with constant arguments.  This can be
  31   /// useful when looking for standard library functions we should constant fold
  32   /// or handle in alias analyses.
  33   struct ExternalFunctionsPassedConstants : public ModulePass {
  34     static char ID; // Pass ID, replacement for typeid
  35     ExternalFunctionsPassedConstants() : ModulePass(&ID) {}
  36     virtual bool runOnModule(Module &M) {
  37       for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
  38         if (!I->isDeclaration()) continue;
  39
  40         bool PrintedFn = false;
  41         for (Value::use_iterator UI = I->use_begin(), E = I->use_end();
  42              UI != E; ++UI) {
  43           Instruction *User = dyn_cast<Instruction>(*UI);
  44           if (!User) continue;
  45
  46           CallSite CS = CallSite::get(User);
  47           if (!CS.getInstruction()) continue;
  48
  49           for (CallSite::arg_iterator AI = CS.arg_begin(),
  50                E = CS.arg_end(); AI != E; ++AI) {
  51             if (!isa<Constant>(*AI)) continue;
  52
  53             if (!PrintedFn) {
  54               errs() << "Function '" << I->getName() << "':\n";
  55               PrintedFn = true;
  56             }
  57             errs() << *User;
  58             break;
  59           }
  60         }
  61       }
  62
  63       return false;
  64     }
  65
  66     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
  67       AU.setPreservesAll();
  68     }
  69   };
  70
  71   char ExternalFunctionsPassedConstants::ID = 0;
  72   RegisterPass<ExternalFunctionsPassedConstants>
  73   P1("print-externalfnconstants",
  74      "Print external fn callsites passed constants");
  75
  76   struct CallGraphPrinter : public ModulePass {
  77     static char ID; // Pass ID, replacement for typeid
  78     CallGraphPrinter() : ModulePass(&ID) {}
  79
  80     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
  81       AU.setPreservesAll();
  82       AU.addRequiredTransitive<CallGraph>();
  83     }
  84     virtual bool runOnModule(Module &M) {
  85       getAnalysis<CallGraph>().print(errs(), &M);
  86       return false;
  87     }
  88   };
  89
  90   char CallGraphPrinter::ID = 0;
  91   RegisterPass<CallGraphPrinter>
  92     P2("print-callgraph", "Print a call graph");
  93 }