xref: /llvm-project/llvm/tools/llvm-as/llvm-as.cpp (revision 6f43f6d136b69ffd31dee04281f96c2a1d7d2270)
1 //===------------------------------------------------------------------------===
2 // LLVM 'AS' UTILITY
3 //
4 //  This utility may be invoked in the following manner:
5 //   as --help     - Output information about command line switches
6 //   as [options]      - Read LLVM assembly from stdin, write bytecode to stdout
7 //   as [options] x.ll - Read LLVM assembly from the x.ll file, write bytecode
8 //                       to the x.bc file.
9 //
10 //===------------------------------------------------------------------------===
11 
12 #include "llvm/Module.h"
13 #include "llvm/Assembly/Parser.h"
14 #include "llvm/Bytecode/Writer.h"
15 #include "Support/CommandLine.h"
16 #include "Support/Signals.h"
17 #include <fstream>
18 #include <memory>
19 using std::cerr;
20 using std::string;
21 
22 static cl::opt<string>
23 InputFilename(cl::Positional, cl::desc("<input .llvm file>"), cl::init("-"));
24 
25 static cl::opt<string>
26 OutputFilename("o", cl::desc("Override output filename"),
27                cl::value_desc("filename"));
28 
29 static cl::opt<bool>
30 Force("f", cl::desc("Overwrite output files"));
31 
32 static cl::opt<bool>
33 DumpAsm("d", cl::desc("Print assembly as parsed"), cl::Hidden);
34 
35 int main(int argc, char **argv) {
36   cl::ParseCommandLineOptions(argc, argv, " llvm .ll -> .bc assembler\n");
37 
38   std::ostream *Out = 0;
39   try {
40     // Parse the file now...
41     std::auto_ptr<Module> M(ParseAssemblyFile(InputFilename));
42     if (M.get() == 0) {
43       cerr << argv[0] << ": assembly didn't read correctly.\n";
44       return 1;
45     }
46 
47     if (DumpAsm) cerr << "Here's the assembly:\n" << M.get();
48 
49     if (OutputFilename != "") {   // Specified an output filename?
50       if (!Force && std::ifstream(OutputFilename.c_str())) {
51         // If force is not specified, make sure not to overwrite a file!
52         cerr << argv[0] << ": error opening '" << OutputFilename
53              << "': file exists!\n"
54              << "Use -f command line argument to force output\n";
55         return 1;
56       }
57       Out = new std::ofstream(OutputFilename.c_str());
58     } else {
59       if (InputFilename == "-") {
60 	OutputFilename = "-";
61 	Out = &std::cout;
62       } else {
63 	std::string IFN = InputFilename;
64 	int Len = IFN.length();
65 	if (IFN[Len-3] == '.' && IFN[Len-2] == 'l' && IFN[Len-1] == 'l') {
66 	  // Source ends in .ll
67 	  OutputFilename = std::string(IFN.begin(), IFN.end()-3);
68         } else {
69 	  OutputFilename = IFN;   // Append a .bc to it
70 	}
71 	OutputFilename += ".bc";
72 
73         if (!Force && std::ifstream(OutputFilename.c_str())) {
74           // If force is not specified, make sure not to overwrite a file!
75           cerr << argv[0] << ": error opening '" << OutputFilename
76                << "': file exists!\n"
77                << "Use -f command line argument to force output\n";
78           return 1;
79         }
80 
81 	Out = new std::ofstream(OutputFilename.c_str());
82         // Make sure that the Out file gets unlink'd from the disk if we get a
83         // SIGINT
84         RemoveFileOnSignal(OutputFilename);
85       }
86     }
87 
88     if (!Out->good()) {
89       cerr << argv[0] << ": error opening " << OutputFilename << "!\n";
90       return 1;
91     }
92 
93     WriteBytecodeToFile(M.get(), *Out);
94   } catch (const ParseException &E) {
95     cerr << argv[0] << ": " << E.getMessage() << "\n";
96     return 1;
97   }
98 
99   if (Out != &std::cout) delete Out;
100   return 0;
101 }
102 
103