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 using namespace llvm;
  26
  27 namespace {
  28   /// ExternalFunctionsPassedConstants - This pass prints out call sites to
  29   /// external functions that are called with constant arguments.  This can be
  30   /// useful when looking for standard library functions we should constant fold
  31   /// or handle in alias analyses.
  32   struct ExternalFunctionsPassedConstants : public ModulePass {
  33     static char ID; // Pass ID, replacement for typeid
  34     ExternalFunctionsPassedConstants() : ModulePass(ID) {}
  35     virtual bool runOnModule(Module &M) {
  36       for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
  37         if (!I->isDeclaration()) continue;
  38
  39         bool PrintedFn = false;
  40         for (Value::use_iterator UI = I->use_begin(), E = I->use_end();
  41              UI != E; ++UI) {
  42           Instruction *User = dyn_cast<Instruction>(*UI);
  43           if (!User) continue;
  44
  45           CallSite CS(cast<Value>(User));
  46           if (!CS) continue;
  47
  48           for (CallSite::arg_iterator AI = CS.arg_begin(),
  49                E = CS.arg_end(); AI != E; ++AI) {
  50             if (!isa<Constant>(*AI)) continue;
  51
  52             if (!PrintedFn) {
  53               errs() << "Function '" << I->getName() << "':\n";
  54               PrintedFn = true;
  55             }
  56             errs() << *User;
  57             break;
  58           }
  59         }
  60       }
  61
  62       return false;
  63     }
  64
  65     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
  66       AU.setPreservesAll();
  67     }
  68   };
  69 }
  70
  71 char ExternalFunctionsPassedConstants::ID = 0;
  72 static RegisterPass<ExternalFunctionsPassedConstants>
  73   P1("print-externalfnconstants",
  74      "Print external fn callsites passed constants");
  75
  76 namespace {
  77   struct CallGraphPrinter : public ModulePass {
  78     static char ID; // Pass ID, replacement for typeid
  79     CallGraphPrinter() : ModulePass(ID) {}
  80
  81     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
  82       AU.setPreservesAll();
  83       AU.addRequiredTransitive<CallGraph>();
  84     }
  85     virtual bool runOnModule(Module &M) {
  86       getAnalysis<CallGraph>().print(errs(), &M);
  87       return false;
  88     }
  89   };
  90 }
  91
  92 char CallGraphPrinter::ID = 0;
  93 static RegisterPass<CallGraphPrinter>
  94   P2("print-callgraph", "Print a call graph");