llvm-link.cpp revision 263508 
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/Analysis/Verifier.h"
17#include "llvm/Bitcode/ReaderWriter.h"
18#include "llvm/IR/LLVMContext.h"
19#include "llvm/IR/Module.h"
20#include "llvm/IRReader/IRReader.h"
21#include "llvm/Support/CommandLine.h"
22#include "llvm/Support/ManagedStatic.h"
23#include "llvm/Support/Path.h"
24#include "llvm/Support/PrettyStackTrace.h"
25#include "llvm/Support/Signals.h"
26#include "llvm/Support/SourceMgr.h"
27#include "llvm/Support/SystemUtils.h"
28#include "llvm/Support/ToolOutputFile.h"
29#include <memory>
30using namespace llvm;
31
32static cl::list<std::string>
33InputFilenames(cl::Positional, cl::OneOrMore,
34               cl::desc("<input bitcode files>"));
35
36static cl::opt<std::string>
37OutputFilename("o", cl::desc("Override output filename"), cl::init("-"),
38               cl::value_desc("filename"));
39
40static cl::opt<bool>
41Force("f", cl::desc("Enable binary output on terminals"));
42
43static cl::opt<bool>
44OutputAssembly("S",
45         cl::desc("Write output as LLVM assembly"), cl::Hidden);
46
47static cl::opt<bool>
48Verbose("v", cl::desc("Print information about actions taken"));
49
50static cl::opt<bool>
51DumpAsm("d", cl::desc("Print assembly as linked"), cl::Hidden);
52
53// LoadFile - Read the specified bitcode file in and return it.  This routine
54// searches the link path for the specified file to try to find it...
55//
56static inline Module *LoadFile(const char *argv0, const std::string &FN,
57                               LLVMContext& Context) {
58  SMDiagnostic Err;
59  if (Verbose) errs() << "Loading '" << FN << "'\n";
60  Module* Result = 0;
61
62  Result = ParseIRFile(FN, Err, Context);
63  if (Result) return Result;   // Load successful!
64
65  Err.print(argv0, errs());
66  return NULL;
67}
68
69int main(int argc, char **argv) {
70  // Print a stack trace if we signal out.
71  sys::PrintStackTraceOnErrorSignal();
72  PrettyStackTraceProgram X(argc, argv);
73
74  LLVMContext &Context = getGlobalContext();
75  llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
76  cl::ParseCommandLineOptions(argc, argv, "llvm linker\n");
77
78  unsigned BaseArg = 0;
79  std::string ErrorMessage;
80
81  OwningPtr<Module> Composite(LoadFile(argv[0],
82                                       InputFilenames[BaseArg], Context));
83  if (Composite.get() == 0) {
84    errs() << argv[0] << ": error loading file '"
85           << InputFilenames[BaseArg] << "'\n";
86    return 1;
87  }
88
89  Linker L(Composite.get());
90  for (unsigned i = BaseArg+1; i < InputFilenames.size(); ++i) {
91    OwningPtr<Module> M(LoadFile(argv[0], InputFilenames[i], Context));
92    if (M.get() == 0) {
93      errs() << argv[0] << ": error loading file '" <<InputFilenames[i]<< "'\n";
94      return 1;
95    }
96
97    if (Verbose) errs() << "Linking in '" << InputFilenames[i] << "'\n";
98
99    if (L.linkInModule(M.get(), &ErrorMessage)) {
100      errs() << argv[0] << ": link error in '" << InputFilenames[i]
101             << "': " << ErrorMessage << "\n";
102      return 1;
103    }
104  }
105
106  if (DumpAsm) errs() << "Here's the assembly:\n" << *Composite;
107
108  std::string ErrorInfo;
109  tool_output_file Out(OutputFilename.c_str(), ErrorInfo, sys::fs::F_Binary);
110  if (!ErrorInfo.empty()) {
111    errs() << ErrorInfo << '\n';
112    return 1;
113  }
114
115  if (verifyModule(*Composite)) {
116    errs() << argv[0] << ": linked module is broken!\n";
117    return 1;
118  }
119
120  if (Verbose) errs() << "Writing bitcode...\n";
121  if (OutputAssembly) {
122    Out.os() << *Composite;
123  } else if (Force || !CheckBitcodeOutputToConsole(Out.os(), true))
124    WriteBitcodeToFile(Composite.get(), Out.os());
125
126  // Declare success.
127  Out.keep();
128
129  return 0;
130}
131