xref: /llvm-project/llvm/tools/llvm-as/llvm-as.cpp (revision b2d0fa08230d98b55d83b6771f9ab894b6b15ce1)
1 //===--- llvm-as.cpp - The low-level LLVM assembler -----------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source 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 bytecode to stdout
13 //   llvm-as [options] x.ll - Read LLVM asm from the x.ll file, write bytecode
14 //                            to the x.bc file.
15 //
16 //===------------------------------------------------------------------------===
17 
18 #include "llvm/Module.h"
19 #include "llvm/Assembly/Parser.h"
20 #include "llvm/Bytecode/Writer.h"
21 #include "llvm/Analysis/Verifier.h"
22 #include "llvm/Support/CommandLine.h"
23 #include "llvm/System/Signals.h"
24 #include <fstream>
25 #include <iostream>
26 #include <memory>
27 
28 using namespace llvm;
29 
30 static cl::opt<std::string>
31 InputFilename(cl::Positional, cl::desc("<input .llvm file>"), cl::init("-"));
32 
33 static cl::opt<std::string>
34 OutputFilename("o", cl::desc("Override output filename"),
35                cl::value_desc("filename"));
36 
37 static cl::opt<bool>
38 Force("f", cl::desc("Overwrite output files"));
39 
40 static cl::opt<bool>
41 DumpAsm("d", cl::desc("Print assembly as parsed"), cl::Hidden);
42 
43 static cl::opt<bool>
44 NoCompress("disable-compression", cl::init(false),
45            cl::desc("Don't ompress the generated bytecode"));
46 
47 static cl::opt<bool>
48 DisableVerify("disable-verify", cl::Hidden,
49               cl::desc("Do not run verifier on input LLVM (dangerous!)"));
50 
51 int main(int argc, char **argv) {
52   cl::ParseCommandLineOptions(argc, argv, " llvm .ll -> .bc assembler\n");
53   sys::PrintStackTraceOnErrorSignal();
54 
55   std::ostream *Out = 0;
56   try {
57     // Parse the file now...
58     std::auto_ptr<Module> M(ParseAssemblyFile(InputFilename));
59     if (M.get() == 0) {
60       std::cerr << argv[0] << ": assembly didn't read correctly.\n";
61       return 1;
62     }
63 
64     try {
65       if (!DisableVerify)
66         verifyModule(*M.get(), ThrowExceptionAction);
67     } catch (const std::string &Err) {
68       std::cerr << argv[0]
69                 << ": assembly parsed, but does not verify as correct!\n";
70       std::cerr << Err;
71       return 1;
72     }
73 
74     if (DumpAsm) std::cerr << "Here's the assembly:\n" << M.get();
75 
76     if (OutputFilename != "") {   // Specified an output filename?
77       if (OutputFilename != "-") {  // Not stdout?
78         if (!Force && std::ifstream(OutputFilename.c_str())) {
79           // If force is not specified, make sure not to overwrite a file!
80           std::cerr << argv[0] << ": error opening '" << OutputFilename
81                     << "': file exists!\n"
82                     << "Use -f command line argument to force output\n";
83           return 1;
84         }
85         Out = new std::ofstream(OutputFilename.c_str(), std::ios_base::out |
86                                 std::ios_base::trunc | std::ios_base::binary);
87       } else {                      // Specified stdout
88 	Out = &std::cout;
89       }
90     } else {
91       if (InputFilename == "-") {
92 	OutputFilename = "-";
93 	Out = &std::cout;
94       } else {
95 	std::string IFN = InputFilename;
96 	int Len = IFN.length();
97 	if (IFN[Len-3] == '.' && IFN[Len-2] == 'l' && IFN[Len-1] == 'l') {
98 	  // Source ends in .ll
99 	  OutputFilename = std::string(IFN.begin(), IFN.end()-3);
100         } else {
101 	  OutputFilename = IFN;   // Append a .bc to it
102 	}
103 	OutputFilename += ".bc";
104 
105         if (!Force && std::ifstream(OutputFilename.c_str())) {
106           // If force is not specified, make sure not to overwrite a file!
107           std::cerr << argv[0] << ": error opening '" << OutputFilename
108                     << "': file exists!\n"
109                     << "Use -f command line argument to force output\n";
110           return 1;
111         }
112 
113 	Out = new std::ofstream(OutputFilename.c_str(), std::ios_base::out |
114                                 std::ios_base::trunc | std::ios_base::binary);
115         // Make sure that the Out file gets unlinked from the disk if we get a
116         // SIGINT
117         sys::RemoveFileOnSignal(sys::Path(OutputFilename));
118       }
119     }
120 
121     if (!Out->good()) {
122       std::cerr << argv[0] << ": error opening " << OutputFilename << "!\n";
123       return 1;
124     }
125 
126     WriteBytecodeToFile(M.get(), *Out, !NoCompress);
127   } catch (const ParseException &E) {
128     std::cerr << argv[0] << ": " << E.getMessage() << "\n";
129     return 1;
130   }
131 
132   if (Out != &std::cout) delete Out;
133   return 0;
134 }
135 
136