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"
25using namespace llvm;
26
27namespace {
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
71char ExternalFunctionsPassedConstants::ID = 0;
72static RegisterPass<ExternalFunctionsPassedConstants>
73  P1("print-externalfnconstants",
74     "Print external fn callsites passed constants");
75
76namespace {
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
92char CallGraphPrinter::ID = 0;
93static RegisterPass<CallGraphPrinter>
94  P2("print-callgraph", "Print a call graph");
95