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      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/Analysis/CallGraph.h"
     21 #include "llvm/IR/Module.h"
     22 #include "llvm/Pass.h"
     23 #include "llvm/Support/CallSite.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");
     95