xref: /llvm-project/llvm/tools/llvm-as/llvm-as.cpp (revision 7ddec63d8fe687fba5c01eee84f450678521181c)
1 //===--- llvm-as.cpp - The low-level LLVM assembler -----------------------===//
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-as --help         - Output information about command line switches
12 //   llvm-as [options]      - Read LLVM asm from stdin, write bitcode to stdout
13 //   llvm-as [options] x.ll - Read LLVM asm from the x.ll file, write bitcode
14 //                            to the x.bc file.
15 //
16 //===----------------------------------------------------------------------===//
17 
18 #include "llvm/AsmParser/Parser.h"
19 #include "llvm/Bitcode/ReaderWriter.h"
20 #include "llvm/IR/LLVMContext.h"
21 #include "llvm/IR/Module.h"
22 #include "llvm/IR/Verifier.h"
23 #include "llvm/Support/CommandLine.h"
24 #include "llvm/Support/FileSystem.h"
25 #include "llvm/Support/ManagedStatic.h"
26 #include "llvm/Support/PrettyStackTrace.h"
27 #include "llvm/Support/Signals.h"
28 #include "llvm/Support/SourceMgr.h"
29 #include "llvm/Support/SystemUtils.h"
30 #include "llvm/Support/ToolOutputFile.h"
31 #include <memory>
32 using namespace llvm;
33 
34 static cl::opt<std::string> InputFilename(cl::Positional,
35                                           cl::desc("<input .llvm file>"),
36                                           cl::init("-"));
37 
38 static cl::opt<std::string> OutputFilename("o",
39                                            cl::desc("Override output filename"),
40                                            cl::value_desc("filename"));
41 
42 static cl::opt<bool> Force("f", cl::desc("Enable binary output on terminals"));
43 
44 static cl::opt<bool> DisableOutput("disable-output", cl::desc("Disable output"),
45                                    cl::init(false));
46 
47 static cl::opt<bool> EmitSummaryIndex("module-summary",
48                                       cl::desc("Emit module summary index"),
49                                       cl::init(false));
50 
51 static cl::opt<bool> EmitModuleHash("module-hash", cl::desc("Emit module hash"),
52                                     cl::init(false));
53 
54 static cl::opt<bool> DumpAsm("d", cl::desc("Print assembly as parsed"),
55                              cl::Hidden);
56 
57 static cl::opt<bool>
58     DisableVerify("disable-verify", cl::Hidden,
59                   cl::desc("Do not run verifier on input LLVM (dangerous!)"));
60 
61 static cl::opt<bool> PreserveBitcodeUseListOrder(
62     "preserve-bc-uselistorder",
63     cl::desc("Preserve use-list order when writing LLVM bitcode."),
64     cl::init(true), cl::Hidden);
65 
66 static void WriteOutputFile(const Module *M) {
67   // Infer the output filename if needed.
68   if (OutputFilename.empty()) {
69     if (InputFilename == "-") {
70       OutputFilename = "-";
71     } else {
72       StringRef IFN = InputFilename;
73       OutputFilename = (IFN.endswith(".ll") ? IFN.drop_back(3) : IFN).str();
74       OutputFilename += ".bc";
75     }
76   }
77 
78   std::error_code EC;
79   std::unique_ptr<tool_output_file> Out(
80       new tool_output_file(OutputFilename, EC, sys::fs::F_None));
81   if (EC) {
82     errs() << EC.message() << '\n';
83     exit(1);
84   }
85 
86   if (Force || !CheckBitcodeOutputToConsole(Out->os(), true))
87     WriteBitcodeToFile(M, Out->os(), PreserveBitcodeUseListOrder,
88                        EmitSummaryIndex, EmitModuleHash);
89 
90   // Declare success.
91   Out->keep();
92 }
93 
94 int main(int argc, char **argv) {
95   // Print a stack trace if we signal out.
96   sys::PrintStackTraceOnErrorSignal();
97   PrettyStackTraceProgram X(argc, argv);
98   LLVMContext &Context = getGlobalContext();
99   llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
100   cl::ParseCommandLineOptions(argc, argv, "llvm .ll -> .bc assembler\n");
101 
102   // Parse the file now...
103   SMDiagnostic Err;
104   std::unique_ptr<Module> M = parseAssemblyFile(InputFilename, Err, Context);
105   if (!M.get()) {
106     Err.print(argv[0], errs());
107     return 1;
108   }
109 
110   if (!DisableVerify) {
111     std::string ErrorStr;
112     raw_string_ostream OS(ErrorStr);
113     if (verifyModule(*M.get(), &OS)) {
114       errs() << argv[0]
115              << ": assembly parsed, but does not verify as correct!\n";
116       errs() << OS.str();
117       return 1;
118     }
119   }
120 
121   if (DumpAsm)
122     errs() << "Here's the assembly:\n" << *M.get();
123 
124   if (!DisableOutput)
125     WriteOutputFile(M.get());
126 
127   return 0;
128 }
129