xref: /llvm-project/llvm/tools/llvm-as/llvm-as.cpp (revision 7f74a56e2436c40b18a672ad7d58727cd6832329)
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/Assembly/Writer.h"
15 #include "llvm/Bytecode/Writer.h"
16 #include "Support/CommandLine.h"
17 #include <fstream>
18 #include <string>
19 #include <memory>
20 
21 cl::String InputFilename ("", "Parse <arg> file, compile to bytecode", 0, "-");
22 cl::String OutputFilename("o", "Override output filename", cl::NoFlags, "");
23 cl::Flag   Force         ("f", "Overwrite output files", cl::NoFlags, false);
24 cl::Flag   DumpAsm       ("d", "Print assembly as parsed", cl::Hidden, false);
25 
26 int main(int argc, char **argv) {
27   cl::ParseCommandLineOptions(argc, argv, " llvm .ll -> .bc assembler\n");
28 
29   ostream *Out = 0;
30   try {
31     // Parse the file now...
32     std::auto_ptr<Module> C(ParseAssemblyFile(InputFilename));
33     if (C.get() == 0) {
34       cerr << "assembly didn't read correctly.\n";
35       return 1;
36     }
37 
38     if (DumpAsm)
39       cerr << "Here's the assembly:\n" << C.get();
40 
41     if (OutputFilename != "") {   // Specified an output filename?
42       if (!Force && !std::ifstream(OutputFilename.c_str())) {
43         // If force is not specified, make sure not to overwrite a file!
44         cerr << "Error opening '" << OutputFilename << "': File exists!\n"
45              << "Use -f command line argument to force output\n";
46         return 1;
47       }
48       Out = new std::ofstream(OutputFilename.c_str());
49     } else {
50       if (InputFilename == "-") {
51 	OutputFilename = "-";
52 	Out = &cout;
53       } else {
54 	std::string IFN = InputFilename;
55 	int Len = IFN.length();
56 	if (IFN[Len-3] == '.' && IFN[Len-2] == 'l' && IFN[Len-1] == 'l') {
57 	  // Source ends in .ll
58 	  OutputFilename = std::string(IFN.begin(), IFN.end()-3);
59         } else {
60 	  OutputFilename = IFN;   // Append a .bc to it
61 	}
62 	OutputFilename += ".bc";
63 
64         if (!Force && !std::ifstream(OutputFilename.c_str())) {
65           // If force is not specified, make sure not to overwrite a file!
66           cerr << "Error opening '" << OutputFilename << "': File exists!\n"
67                << "Use -f command line argument to force output\n";
68           return 1;
69         }
70 
71 	Out = new std::ofstream(OutputFilename.c_str());
72       }
73     }
74 
75     if (!Out->good()) {
76       cerr << "Error opening " << OutputFilename << "!\n";
77       return 1;
78     }
79 
80     WriteBytecodeToFile(C.get(), *Out);
81   } catch (const ParseException &E) {
82     cerr << E.getMessage() << endl;
83     return 1;
84   }
85 
86   if (Out != &cout) delete Out;
87   return 0;
88 }
89 
90