aboutsummaryrefslogtreecommitdiffstats
path: root/tools/llvm-extract/llvm-extract.cpp
blob: b5af6bc1aaf2511929c35c8cda0eef836562f419 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
//===- llvm-extract.cpp - LLVM function extraction utility ----------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This utility changes the input module to only contain a single function,
// which is primarily used for debugging transformations.
//
//===----------------------------------------------------------------------===//

#include "llvm/LLVMContext.h"
#include "llvm/Module.h"
#include "llvm/PassManager.h"
#include "llvm/Assembly/PrintModulePass.h"
#include "llvm/Bitcode/ReaderWriter.h"
#include "llvm/Transforms/IPO.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/IRReader.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/PrettyStackTrace.h"
#include "llvm/Support/ToolOutputFile.h"
#include "llvm/Support/SystemUtils.h"
#include "llvm/System/Signals.h"
#include "llvm/ADT/SmallPtrSet.h"
#include <memory>
using namespace llvm;

// InputFilename - The filename to read from.
static cl::opt<std::string>
InputFilename(cl::Positional, cl::desc("<input bitcode file>"),
              cl::init("-"), cl::value_desc("filename"));

static cl::opt<std::string>
OutputFilename("o", cl::desc("Specify output filename"),
               cl::value_desc("filename"), cl::init("-"));

static cl::opt<bool>
Force("f", cl::desc("Enable binary output on terminals"));

static cl::opt<bool>
DeleteFn("delete", cl::desc("Delete specified Globals from Module"));

// ExtractFuncs - The functions to extract from the module... 
static cl::list<std::string>
ExtractFuncs("func", cl::desc("Specify function to extract"),
             cl::ZeroOrMore, cl::value_desc("function"));

// ExtractGlobals - The globals to extract from the module...
static cl::list<std::string>
ExtractGlobals("glob", cl::desc("Specify global to extract"),
               cl::ZeroOrMore, cl::value_desc("global"));

static cl::opt<bool>
OutputAssembly("S",
               cl::desc("Write output as LLVM assembly"), cl::Hidden);

int main(int argc, char **argv) {
  // Print a stack trace if we signal out.
  sys::PrintStackTraceOnErrorSignal();
  PrettyStackTraceProgram X(argc, argv);

  LLVMContext &Context = getGlobalContext();
  llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
  cl::ParseCommandLineOptions(argc, argv, "llvm extractor\n");

  // Use lazy loading, since we only care about selected global values.
  SMDiagnostic Err;
  std::auto_ptr<Module> M;
  M.reset(getLazyIRFileModule(InputFilename, Err, Context));

  if (M.get() == 0) {
    Err.Print(argv[0], errs());
    return 1;
  }

  std::vector<GlobalValue *> GVs;

  // Figure out which globals we should extract.
  for (size_t i = 0, e = ExtractGlobals.size(); i != e; ++i) {
    GlobalValue *GV = M.get()->getNamedGlobal(ExtractGlobals[i]);
    if (!GV) {
      errs() << argv[0] << ": program doesn't contain global named '"
             << ExtractGlobals[i] << "'!\n";
      return 1;
    }
    GVs.push_back(GV);
  }

  // Figure out which functions we should extract.
  for (size_t i = 0, e = ExtractFuncs.size(); i != e; ++i) {
    GlobalValue *GV = M.get()->getFunction(ExtractFuncs[i]);
    if (!GV) {
      errs() << argv[0] << ": program doesn't contain function named '"
             << ExtractFuncs[i] << "'!\n";
      return 1;
    }
    GVs.push_back(GV);
  }

  // Materialize requisite global values.
  if (!DeleteFn)
    for (size_t i = 0, e = GVs.size(); i != e; ++i) {
      GlobalValue *GV = GVs[i];
      if (GV->isMaterializable()) {
        std::string ErrInfo;
        if (GV->Materialize(&ErrInfo)) {
          errs() << argv[0] << ": error reading input: " << ErrInfo << "\n";
          return 1;
        }
      }
    }
  else {
    // Deleting. Materialize every GV that's *not* in GVs.
    SmallPtrSet<GlobalValue *, 8> GVSet(GVs.begin(), GVs.end());
    for (Module::global_iterator I = M->global_begin(), E = M->global_end();
         I != E; ++I) {
      GlobalVariable *G = I;
      if (!GVSet.count(G) && G->isMaterializable()) {
        std::string ErrInfo;
        if (G->Materialize(&ErrInfo)) {
          errs() << argv[0] << ": error reading input: " << ErrInfo << "\n";
          return 1;
        }
      }
    }
    for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I) {
      Function *F = I;
      if (!GVSet.count(F) && F->isMaterializable()) {
        std::string ErrInfo;
        if (F->Materialize(&ErrInfo)) {
          errs() << argv[0] << ": error reading input: " << ErrInfo << "\n";
          return 1;
        }
      }
    }
  }

  // In addition to deleting all other functions, we also want to spiff it
  // up a little bit.  Do this now.
  PassManager Passes;
  Passes.add(new TargetData(M.get())); // Use correct TargetData

  Passes.add(createGVExtractionPass(GVs, DeleteFn));
  if (!DeleteFn)
    Passes.add(createGlobalDCEPass());           // Delete unreachable globals
  Passes.add(createStripDeadDebugInfoPass());    // Remove dead debug info
  Passes.add(createDeadTypeEliminationPass());   // Remove dead types...
  Passes.add(createStripDeadPrototypesPass());   // Remove dead func decls

  std::string ErrorInfo;
  tool_output_file Out(OutputFilename.c_str(), ErrorInfo,
                       raw_fd_ostream::F_Binary);
  if (!ErrorInfo.empty()) {
    errs() << ErrorInfo << '\n';
    return 1;
  }

  if (OutputAssembly)
    Passes.add(createPrintModulePass(&Out.os()));
  else if (Force || !CheckBitcodeOutputToConsole(Out.os(), true))
    Passes.add(createBitcodeWriterPass(Out.os()));

  Passes.run(*M.get());

  // Declare success.
  Out.keep();

  return 0;
}