1//===- llvm-link.cpp - Low-level LLVM linker ------------------------------===//
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 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/Linker.h"
16#include "llvm/LLVMContext.h"
17#include "llvm/Module.h"
18#include "llvm/Analysis/Verifier.h"
19#include "llvm/Bitcode/ReaderWriter.h"
20#include "llvm/Support/CommandLine.h"
21#include "llvm/Support/ManagedStatic.h"
22#include "llvm/Support/PrettyStackTrace.h"
23#include "llvm/Support/ToolOutputFile.h"
24#include "llvm/Support/SystemUtils.h"
25#include "llvm/Support/IRReader.h"
26#include "llvm/Support/Signals.h"
27#include "llvm/Support/Path.h"
28#include <memory>
29using namespace llvm;
30
31static cl::list<std::string>
32InputFilenames(cl::Positional, cl::OneOrMore,
33               cl::desc("<input bitcode files>"));
34
35static cl::opt<std::string>
36OutputFilename("o", cl::desc("Override output filename"), cl::init("-"),
37               cl::value_desc("filename"));
38
39static cl::opt<bool>
40Force("f", cl::desc("Enable binary output on terminals"));
41
42static cl::opt<bool>
43OutputAssembly("S",
44         cl::desc("Write output as LLVM assembly"), cl::Hidden);
45
46static cl::opt<bool>
47Verbose("v", cl::desc("Print information about actions taken"));
48
49static cl::opt<bool>
50DumpAsm("d", cl::desc("Print assembly as linked"), cl::Hidden);
51
52// LoadFile - Read the specified bitcode file in and return it.  This routine
53// searches the link path for the specified file to try to find it...
54//
55static inline std::auto_ptr<Module> LoadFile(const char *argv0,
56                                             const std::string &FN,
57                                             LLVMContext& Context) {
58  sys::Path Filename;
59  if (!Filename.set(FN)) {
60    errs() << "Invalid file name: '" << FN << "'\n";
61    return std::auto_ptr<Module>();
62  }
63
64  SMDiagnostic Err;
65  if (Verbose) errs() << "Loading '" << Filename.c_str() << "'\n";
66  Module* Result = 0;
67
68  const std::string &FNStr = Filename.str();
69  Result = ParseIRFile(FNStr, Err, Context);
70  if (Result) return std::auto_ptr<Module>(Result);   // Load successful!
71
72  Err.print(argv0, errs());
73  return std::auto_ptr<Module>();
74}
75
76int main(int argc, char **argv) {
77  // Print a stack trace if we signal out.
78  sys::PrintStackTraceOnErrorSignal();
79  PrettyStackTraceProgram X(argc, argv);
80
81  LLVMContext &Context = getGlobalContext();
82  llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
83  cl::ParseCommandLineOptions(argc, argv, "llvm linker\n");
84
85  unsigned BaseArg = 0;
86  std::string ErrorMessage;
87
88  std::auto_ptr<Module> Composite(LoadFile(argv[0],
89                                           InputFilenames[BaseArg], Context));
90  if (Composite.get() == 0) {
91    errs() << argv[0] << ": error loading file '"
92           << InputFilenames[BaseArg] << "'\n";
93    return 1;
94  }
95
96  for (unsigned i = BaseArg+1; i < InputFilenames.size(); ++i) {
97    std::auto_ptr<Module> M(LoadFile(argv[0],
98                                     InputFilenames[i], Context));
99    if (M.get() == 0) {
100      errs() << argv[0] << ": error loading file '" <<InputFilenames[i]<< "'\n";
101      return 1;
102    }
103
104    if (Verbose) errs() << "Linking in '" << InputFilenames[i] << "'\n";
105
106    if (Linker::LinkModules(Composite.get(), M.get(), Linker::DestroySource,
107                            &ErrorMessage)) {
108      errs() << argv[0] << ": link error in '" << InputFilenames[i]
109             << "': " << ErrorMessage << "\n";
110      return 1;
111    }
112  }
113
114  // TODO: Iterate over the -l list and link in any modules containing
115  // global symbols that have not been resolved so far.
116
117  if (DumpAsm) errs() << "Here's the assembly:\n" << *Composite;
118
119  std::string ErrorInfo;
120  tool_output_file Out(OutputFilename.c_str(), ErrorInfo,
121                       raw_fd_ostream::F_Binary);
122  if (!ErrorInfo.empty()) {
123    errs() << ErrorInfo << '\n';
124    return 1;
125  }
126
127  if (verifyModule(*Composite)) {
128    errs() << argv[0] << ": linked module is broken!\n";
129    return 1;
130  }
131
132  if (Verbose) errs() << "Writing bitcode...\n";
133  if (OutputAssembly) {
134    Out.os() << *Composite;
135  } else if (Force || !CheckBitcodeOutputToConsole(Out.os(), true))
136    WriteBitcodeToFile(Composite.get(), Out.os());
137
138  // Declare success.
139  Out.keep();
140
141  return 0;
142}
143