llvm-link.cpp revision 36b56886974eae4f9c5ebc96befd3e7bfe5de338 
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/Linker.h"
16#include "llvm/Bitcode/ReaderWriter.h"
17#include "llvm/IR/LLVMContext.h"
18#include "llvm/IR/Module.h"
19#include "llvm/IR/Verifier.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
53static cl::opt<bool>
54SuppressWarnings("suppress-warnings", cl::desc("Suppress all linking warnings"),
55                 cl::init(false));
56
57// LoadFile - Read the specified bitcode file in and return it.  This routine
58// searches the link path for the specified file to try to find it...
59//
60static inline Module *LoadFile(const char *argv0, const std::string &FN,
61                               LLVMContext& Context) {
62  SMDiagnostic Err;
63  if (Verbose) errs() << "Loading '" << FN << "'\n";
64  Module* Result = 0;
65
66  Result = ParseIRFile(FN, Err, Context);
67  if (Result) return Result;   // Load successful!
68
69  Err.print(argv0, errs());
70  return NULL;
71}
72
73int main(int argc, char **argv) {
74  // Print a stack trace if we signal out.
75  sys::PrintStackTraceOnErrorSignal();
76  PrettyStackTraceProgram X(argc, argv);
77
78  LLVMContext &Context = getGlobalContext();
79  llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
80  cl::ParseCommandLineOptions(argc, argv, "llvm linker\n");
81
82  unsigned BaseArg = 0;
83  std::string ErrorMessage;
84
85  std::unique_ptr<Module> Composite(
86      LoadFile(argv[0], InputFilenames[BaseArg], Context));
87  if (Composite.get() == 0) {
88    errs() << argv[0] << ": error loading file '"
89           << InputFilenames[BaseArg] << "'\n";
90    return 1;
91  }
92
93  Linker L(Composite.get(), SuppressWarnings);
94  for (unsigned i = BaseArg+1; i < InputFilenames.size(); ++i) {
95    std::unique_ptr<Module> M(LoadFile(argv[0], InputFilenames[i], Context));
96    if (M.get() == 0) {
97      errs() << argv[0] << ": error loading file '" <<InputFilenames[i]<< "'\n";
98      return 1;
99    }
100
101    if (Verbose) errs() << "Linking in '" << InputFilenames[i] << "'\n";
102
103    if (L.linkInModule(M.get(), &ErrorMessage)) {
104      errs() << argv[0] << ": link error in '" << InputFilenames[i]
105             << "': " << ErrorMessage << "\n";
106      return 1;
107    }
108  }
109
110  if (DumpAsm) errs() << "Here's the assembly:\n" << *Composite;
111
112  std::string ErrorInfo;
113  tool_output_file Out(OutputFilename.c_str(), ErrorInfo, sys::fs::F_None);
114  if (!ErrorInfo.empty()) {
115    errs() << ErrorInfo << '\n';
116    return 1;
117  }
118
119  if (verifyModule(*Composite)) {
120    errs() << argv[0] << ": linked module is broken!\n";
121    return 1;
122  }
123
124  if (Verbose) errs() << "Writing bitcode...\n";
125  if (OutputAssembly) {
126    Out.os() << *Composite;
127  } else if (Force || !CheckBitcodeOutputToConsole(Out.os(), true))
128    WriteBitcodeToFile(Composite.get(), Out.os());
129
130  // Declare success.
131  Out.keep();
132
133  return 0;
134}
135