xref: /llvm-project/llvm/tools/llvm-as/llvm-as.cpp (revision 2d5487cf446f9a58f6d2f76df33102423c83f285)
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/Analysis/ModuleSummaryAnalysis.h"
19 #include "llvm/AsmParser/Parser.h"
20 #include "llvm/Bitcode/ReaderWriter.h"
21 #include "llvm/IR/LLVMContext.h"
22 #include "llvm/IR/Module.h"
23 #include "llvm/IR/Verifier.h"
24 #include "llvm/Support/CommandLine.h"
25 #include "llvm/Support/FileSystem.h"
26 #include "llvm/Support/ManagedStatic.h"
27 #include "llvm/Support/PrettyStackTrace.h"
28 #include "llvm/Support/Signals.h"
29 #include "llvm/Support/SourceMgr.h"
30 #include "llvm/Support/SystemUtils.h"
31 #include "llvm/Support/ToolOutputFile.h"
32 #include <memory>
33 using namespace llvm;
34 
35 static cl::opt<std::string> InputFilename(cl::Positional,
36                                           cl::desc("<input .llvm file>"),
37                                           cl::init("-"));
38 
39 static cl::opt<std::string> OutputFilename("o",
40                                            cl::desc("Override output filename"),
41                                            cl::value_desc("filename"));
42 
43 static cl::opt<bool> Force("f", cl::desc("Enable binary output on terminals"));
44 
45 static cl::opt<bool> DisableOutput("disable-output", cl::desc("Disable output"),
46                                    cl::init(false));
47 
48 static cl::opt<bool> EmitSummaryIndex("module-summary",
49                                       cl::desc("Emit module summary index"),
50                                       cl::init(false));
51 
52 static cl::opt<bool> EmitModuleHash("module-hash", cl::desc("Emit module hash"),
53                                     cl::init(false));
54 
55 static cl::opt<bool> DumpAsm("d", cl::desc("Print assembly as parsed"),
56                              cl::Hidden);
57 
58 static cl::opt<bool>
59     DisableVerify("disable-verify", cl::Hidden,
60                   cl::desc("Do not run verifier on input LLVM (dangerous!)"));
61 
62 static cl::opt<bool> PreserveBitcodeUseListOrder(
63     "preserve-bc-uselistorder",
64     cl::desc("Preserve use-list order when writing LLVM bitcode."),
65     cl::init(true), cl::Hidden);
66 
67 static void WriteOutputFile(const Module *M) {
68   // Infer the output filename if needed.
69   if (OutputFilename.empty()) {
70     if (InputFilename == "-") {
71       OutputFilename = "-";
72     } else {
73       StringRef IFN = InputFilename;
74       OutputFilename = (IFN.endswith(".ll") ? IFN.drop_back(3) : IFN).str();
75       OutputFilename += ".bc";
76     }
77   }
78 
79   std::error_code EC;
80   std::unique_ptr<tool_output_file> Out(
81       new tool_output_file(OutputFilename, EC, sys::fs::F_None));
82   if (EC) {
83     errs() << EC.message() << '\n';
84     exit(1);
85   }
86 
87   if (Force || !CheckBitcodeOutputToConsole(Out->os(), true)) {
88     std::unique_ptr<ModuleSummaryIndex> Index;
89     if (EmitSummaryIndex)
90       Index = ModuleSummaryIndexBuilder(M).takeIndex();
91 
92     WriteBitcodeToFile(M, Out->os(), PreserveBitcodeUseListOrder, Index.get(),
93                        EmitModuleHash);
94   }
95 
96   // Declare success.
97   Out->keep();
98 }
99 
100 int main(int argc, char **argv) {
101   // Print a stack trace if we signal out.
102   sys::PrintStackTraceOnErrorSignal();
103   PrettyStackTraceProgram X(argc, argv);
104   LLVMContext &Context = getGlobalContext();
105   llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
106   cl::ParseCommandLineOptions(argc, argv, "llvm .ll -> .bc assembler\n");
107 
108   // Parse the file now...
109   SMDiagnostic Err;
110   std::unique_ptr<Module> M = parseAssemblyFile(InputFilename, Err, Context);
111   if (!M.get()) {
112     Err.print(argv[0], errs());
113     return 1;
114   }
115 
116   if (!DisableVerify) {
117     std::string ErrorStr;
118     raw_string_ostream OS(ErrorStr);
119     if (verifyModule(*M.get(), &OS)) {
120       errs() << argv[0]
121              << ": assembly parsed, but does not verify as correct!\n";
122       errs() << OS.str();
123       return 1;
124     }
125   }
126 
127   if (DumpAsm)
128     errs() << "Here's the assembly:\n" << *M.get();
129 
130   if (!DisableOutput)
131     WriteOutputFile(M.get());
132 
133   return 0;
134 }
135