xref: /llvm-project/llvm/tools/llvm-as/llvm-as.cpp (revision 3c707196ac7c51682e352cda032248c1406530b8)
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 <fstream>
17 #include <string>
18 #include <memory>
19 
20 cl::String InputFilename ("", "Parse <arg> file, compile to bytecode", 0, "-");
21 cl::String OutputFilename("o", "Override output filename", cl::NoFlags, "");
22 cl::Flag   Force         ("f", "Overwrite output files", cl::NoFlags, false);
23 cl::Flag   DumpAsm       ("d", "Print assembly as parsed", cl::Hidden, false);
24 
25 int main(int argc, char **argv) {
26   cl::ParseCommandLineOptions(argc, argv, " llvm .ll -> .bc assembler\n");
27 
28   ostream *Out = 0;
29   try {
30     // Parse the file now...
31     std::auto_ptr<Module> M(ParseAssemblyFile(InputFilename));
32     if (M.get() == 0) {
33       cerr << "assembly didn't read correctly.\n";
34       return 1;
35     }
36 
37     if (DumpAsm) {
38       cerr << "Here's the assembly:\n";
39       M.get()->dump();
40     }
41 
42     if (OutputFilename != "") {   // Specified an output filename?
43       if (!Force && std::ifstream(OutputFilename.c_str())) {
44         // If force is not specified, make sure not to overwrite a file!
45         cerr << "Error opening '" << OutputFilename << "': File exists!\n"
46              << "Use -f command line argument to force output\n";
47         return 1;
48       }
49       Out = new std::ofstream(OutputFilename.c_str());
50     } else {
51       if (InputFilename == "-") {
52 	OutputFilename = "-";
53 	Out = &cout;
54       } else {
55 	std::string IFN = InputFilename;
56 	int Len = IFN.length();
57 	if (IFN[Len-3] == '.' && IFN[Len-2] == 'l' && IFN[Len-1] == 'l') {
58 	  // Source ends in .ll
59 	  OutputFilename = std::string(IFN.begin(), IFN.end()-3);
60         } else {
61 	  OutputFilename = IFN;   // Append a .bc to it
62 	}
63 	OutputFilename += ".bc";
64 
65         if (!Force && std::ifstream(OutputFilename.c_str())) {
66           // If force is not specified, make sure not to overwrite a file!
67           cerr << "Error opening '" << OutputFilename << "': File exists!\n"
68                << "Use -f command line argument to force output\n";
69           return 1;
70         }
71 
72 	Out = new std::ofstream(OutputFilename.c_str());
73       }
74     }
75 
76     if (!Out->good()) {
77       cerr << "Error opening " << OutputFilename << "!\n";
78       return 1;
79     }
80 
81     WriteBytecodeToFile(M.get(), *Out);
82   } catch (const ParseException &E) {
83     cerr << E.getMessage() << endl;
84     return 1;
85   }
86 
87   if (Out != &cout) delete Out;
88   return 0;
89 }
90 
91