1 files changed, 75 insertions, 5 deletions

diff --git a/src/main.cff b/src/main.cff
index b8829a7..9f9181c 100644
--- a/src/main.cff
+++ b/src/main.cff
@@ -1,21 +1,91 @@
 import "cffc.hff";
 import "common.hff";
 
+fn prihelp(f *FILE, progname *const u8) void {
+   fprintf(f, "Usage: %s: [OPTION]... [FILE]\n", progname);
+   fprintf(f, "Compile cffc source code in FILE\n"
+              "\n"
+              "Options:\n"
+              "    --help, -h:\t\tshow this help message\n" 
+              "    --target triple:\tset compilation target triple\n"
+              "    -:\t\t\tread input from stdin\n"
+              "    -o -:\t\tset output to stdout\n"
+              "    -o path:\t\tset output file path\n");
+}
+
 extern fn main(argc int, argv **u8) int {
-   assert(argc > 1, "args?");
+   let triple = #null;
+   let path *const u8 = #null;
+   let outfile *FILE = #null;
+   for let i = 1; i < argc; ++i {
+      let arg = argv[i];
+      defmacro nextarg() [
+         (do let $next = argv[++i];
+             if $next == #null {
+               fprintf(stderr, "%s: error: argument expected after `%s'\n", argv[0], arg);
+               fprintf(stderr, "Try '%s --help' for more information\n", argv[0]);
+               return 1;
+             }
+             $next;);
+      ]
+      switch {
+      case streq(arg, "-h") or streq(arg, "--help");
+         prihelp(stdout, argv[1]);
+         return 0;
+
+      case streq(arg, "-");
+         path = "/dev/stdin";
+
+      case streq(arg, "--target");
+         triple = nextarg();
+         
+      case streq(arg, "-o");
+         let outpath = nextarg();
+         outfile = streq(outpath, "-") ? stdout : fopen(outpath, "wb");
+         if outfile == #null {
+            fprintf(stderr, "%s: error: cannot open '%s': %s\n", argv[0], outpath, strerror(errno));
+            return 1;
+         }
+
+      case *arg == '-';
+         fprintf(stderr, "%s: error: unknown option '%s'\n1", argv[0], arg);
+         fprintf(stderr, "Try '%s --help' for more information\n", argv[0]);
+         return 1;
+
+      case else
+         if path {
+            fprintf(stderr, "%s: error: path was already given\n", argv[0]);
+            fprintf(stderr, "Try '%s --help' for more information\n", argv[0]);
+            return 1;
+         }
+         path = arg;         
+      }
+   }
+
+   if path == #null {
+      fprintf(stderr, "%s: error: no input file\n", argv[0]);
+      fprintf(stderr, "Try '%s --help' for more information\n", argv[0]);
+      return 1;
+   }
+
+   if outfile == #null {
+      fprintf(stderr, "%s: error: no output file\n", argv[0]);
+      fprintf(stderr, "Try '%s --help' for more information\n", argv[0]);
+      return 1;
+   }
 
-   let triple = host_target_triple;
+   triple = triple ?? host_target_triple;
    let targ = triple2targ(triple);
    if targ == #null {
-      fprintf(stderr, "error: unsupported target triple `%s'\n", triple);
+      fprintf(stderr, "%s: error: unsupported target triple `%s'\n", argv[0], triple);
       return 1;
    }
    targ_ini(targ);
    g_targ.triple = triple;
 
    let p = Parser {};
-   parser_init(&p, argv[1]);
-   llvm_init(stdout);
+   parser_init(&p, path);
+   llvm_init(outfile);
    let decls = parse(&p);
    defer free(decls.#ptr);
    if p.error { return 1; }