xref: /llvm-project/llvm/tools/llvm-as/llvm-as.cpp (revision 4a84ad57a9e3ad7ff99ba3369e933f9671cd2d0f)
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 "llvm/Analysis/Verifier.h"
16 #include "Support/CommandLine.h"
17 #include "Support/Signals.h"
18 #include <fstream>
19 #include <memory>
20 using std::cerr;
21 using std::string;
22 
23 static cl::opt<string>
24 InputFilename(cl::Positional, cl::desc("<input .llvm file>"), cl::init("-"));
25 
26 static cl::opt<string>
27 OutputFilename("o", cl::desc("Override output filename"),
28                cl::value_desc("filename"));
29 
30 static cl::opt<bool>
31 Force("f", cl::desc("Overwrite output files"));
32 
33 static cl::opt<bool>
34 DumpAsm("d", cl::desc("Print assembly as parsed"), cl::Hidden);
35 
36 int main(int argc, char **argv) {
37   cl::ParseCommandLineOptions(argc, argv, " llvm .ll -> .bc assembler\n");
38 
39   std::ostream *Out = 0;
40   try {
41     // Parse the file now...
42     std::auto_ptr<Module> M(ParseAssemblyFile(InputFilename));
43     if (M.get() == 0) {
44       cerr << argv[0] << ": assembly didn't read correctly.\n";
45       return 1;
46     }
47 
48     if (verifyModule(*M.get())) {
49       cerr << argv[0] << ": assembly parsed, but does not verify as correct!\n";
50       return 1;
51     }
52 
53 
54     if (DumpAsm) cerr << "Here's the assembly:\n" << M.get();
55 
56     if (OutputFilename != "") {   // Specified an output filename?
57       if (!Force && std::ifstream(OutputFilename.c_str())) {
58         // If force is not specified, make sure not to overwrite a file!
59         cerr << argv[0] << ": error opening '" << OutputFilename
60              << "': file exists!\n"
61              << "Use -f command line argument to force output\n";
62         return 1;
63       }
64       Out = new std::ofstream(OutputFilename.c_str());
65     } else {
66       if (InputFilename == "-") {
67 	OutputFilename = "-";
68 	Out = &std::cout;
69       } else {
70 	std::string IFN = InputFilename;
71 	int Len = IFN.length();
72 	if (IFN[Len-3] == '.' && IFN[Len-2] == 'l' && IFN[Len-1] == 'l') {
73 	  // Source ends in .ll
74 	  OutputFilename = std::string(IFN.begin(), IFN.end()-3);
75         } else {
76 	  OutputFilename = IFN;   // Append a .bc to it
77 	}
78 	OutputFilename += ".bc";
79 
80         if (!Force && std::ifstream(OutputFilename.c_str())) {
81           // If force is not specified, make sure not to overwrite a file!
82           cerr << argv[0] << ": error opening '" << OutputFilename
83                << "': file exists!\n"
84                << "Use -f command line argument to force output\n";
85           return 1;
86         }
87 
88 	Out = new std::ofstream(OutputFilename.c_str());
89         // Make sure that the Out file gets unlink'd from the disk if we get a
90         // SIGINT
91         RemoveFileOnSignal(OutputFilename);
92       }
93     }
94 
95     if (!Out->good()) {
96       cerr << argv[0] << ": error opening " << OutputFilename << "!\n";
97       return 1;
98     }
99 
100     WriteBytecodeToFile(M.get(), *Out);
101   } catch (const ParseException &E) {
102     cerr << argv[0] << ": " << E.getMessage() << "\n";
103     return 1;
104   }
105 
106   if (Out != &std::cout) delete Out;
107   return 0;
108 }
109 
110