llvm-link.cpp revision 227b6d00dd1faee07c921c7e2256e0fca737d2e5 
1//===- llvm-link.cpp - Low-level LLVM linker ------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by the LLVM research group and is distributed under
6// the University of Illinois Open Source License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This utility may be invoked in the following manner:
11//  llvm-link a.bc b.bc c.bc -o x.bc
12//
13//===----------------------------------------------------------------------===//
14
15#include "llvm/Module.h"
16#include "llvm/Analysis/Verifier.h"
17#include "llvm/Bytecode/Reader.h"
18#include "llvm/Bytecode/Writer.h"
19#include "llvm/Support/Linker.h"
20#include "llvm/Support/CommandLine.h"
21#include "llvm/System/Signals.h"
22#include "llvm/System/Path.h"
23#include <fstream>
24#include <iostream>
25#include <memory>
26
27using namespace llvm;
28
29static cl::list<std::string>
30InputFilenames(cl::Positional, cl::OneOrMore,
31               cl::desc("<input bytecode files>"));
32
33static cl::opt<std::string>
34OutputFilename("o", cl::desc("Override output filename"), cl::init("-"),
35               cl::value_desc("filename"));
36
37static cl::opt<bool> Force("f", cl::desc("Overwrite output files"));
38
39static cl::opt<bool>
40Verbose("v", cl::desc("Print information about actions taken"));
41
42static cl::opt<bool>
43DumpAsm("d", cl::desc("Print assembly as linked"), cl::Hidden);
44
45static cl::opt<bool> NoCompress("disable-compression", cl::init(false),
46       cl::desc("Don't ompress the generated bytecode"));
47
48// LoadFile - Read the specified bytecode file in and return it.  This routine
49// searches the link path for the specified file to try to find it...
50//
51static inline std::auto_ptr<Module> LoadFile(const std::string &FN) {
52  sys::Path Filename;
53  if (!Filename.setFile(FN)) {
54    std::cerr << "Invalid file name: '" << FN << "'\n";
55    return std::auto_ptr<Module>();
56  }
57
58  std::string ErrorMessage;
59  if (Filename.exists()) {
60    if (Verbose) std::cerr << "Loading '" << Filename.c_str() << "'\n";
61    Module* Result = ParseBytecodeFile(Filename.get(), &ErrorMessage);
62    if (Result) return std::auto_ptr<Module>(Result);   // Load successful!
63
64    if (Verbose) {
65      std::cerr << "Error opening bytecode file: '" << Filename.c_str() << "'";
66      if (ErrorMessage.size()) std::cerr << ": " << ErrorMessage;
67      std::cerr << "\n";
68    }
69  } else {
70    std::cerr << "Bytecode file: '" << Filename.c_str()
71              << "' does not exist.\n";
72  }
73
74  return std::auto_ptr<Module>();
75}
76
77int main(int argc, char **argv) {
78  cl::ParseCommandLineOptions(argc, argv, " llvm linker\n");
79  sys::PrintStackTraceOnErrorSignal();
80  assert(InputFilenames.size() > 0 && "OneOrMore is not working");
81
82  unsigned BaseArg = 0;
83  std::string ErrorMessage;
84
85  std::auto_ptr<Module> Composite(LoadFile(InputFilenames[BaseArg]));
86  if (Composite.get() == 0) {
87    std::cerr << argv[0] << ": error loading file '"
88              << InputFilenames[BaseArg] << "'\n";
89    return 1;
90  }
91
92  for (unsigned i = BaseArg+1; i < InputFilenames.size(); ++i) {
93    std::auto_ptr<Module> M(LoadFile(InputFilenames[i]));
94    if (M.get() == 0) {
95      std::cerr << argv[0] << ": error loading file '"
96                << InputFilenames[i] << "'\n";
97      return 1;
98    }
99
100    if (Verbose) std::cerr << "Linking in '" << InputFilenames[i] << "'\n";
101
102    if (LinkModules(Composite.get(), M.get(), &ErrorMessage)) {
103      std::cerr << argv[0] << ": link error in '" << InputFilenames[i]
104                << "': " << ErrorMessage << "\n";
105      return 1;
106    }
107  }
108
109  // TODO: Iterate over the -l list and link in any modules containing
110  // global symbols that have not been resolved so far.
111
112  if (DumpAsm) std::cerr << "Here's the assembly:\n" << Composite.get();
113
114  std::ostream *Out = &std::cout;  // Default to printing to stdout...
115  if (OutputFilename != "-") {
116    if (!Force && std::ifstream(OutputFilename.c_str())) {
117      // If force is not specified, make sure not to overwrite a file!
118      std::cerr << argv[0] << ": error opening '" << OutputFilename
119                << "': file exists!\n"
120                << "Use -f command line argument to force output\n";
121      return 1;
122    }
123    Out = new std::ofstream(OutputFilename.c_str());
124    if (!Out->good()) {
125      std::cerr << argv[0] << ": error opening '" << OutputFilename << "'!\n";
126      return 1;
127    }
128
129    // Make sure that the Out file gets unlinked from the disk if we get a
130    // SIGINT
131    sys::RemoveFileOnSignal(sys::Path(OutputFilename));
132  }
133
134  if (verifyModule(*Composite.get())) {
135    std::cerr << argv[0] << ": linked module is broken!\n";
136    return 1;
137  }
138
139  if (Verbose) std::cerr << "Writing bytecode...\n";
140  WriteBytecodeToFile(Composite.get(), *Out, !NoCompress);
141
142  if (Out != &std::cout) delete Out;
143  return 0;
144}
145