4624

Start requiring a '-o' flag to designate the output binary when translating.

Things currently get funky if you pass in multiple inputs, but that's ok.
This is the first step to supporting multiple input files for a single
output binary.

1 files changed, 38 insertions, 11 deletions

diff --git a/subx/028translate.cc b/subx/028translate.cc
index 174a863a..303d6219 100644
--- a/subx/028translate.cc
+++ b/subx/028translate.cc
@@ -19,30 +19,57 @@
 :(before "End Main")
 if (is_equal(argv[1], "translate")) {
   START_TRACING_UNTIL_END_OF_SCOPE;
-  assert(argc > 3);
   reset();
   program p;
-  ifstream fin(argv[2]);
-  if (!fin) {
-    cerr << "could not open " << argv[2] << '\n';
-    return 1;
+  string output_filename;
+  for (int i = /*skip 'subx translate'*/2;  i < argc;  ++i) {
+    if (is_equal(argv[i], "-o")) {
+      ++i;
+      if (i >= argc) {
+        print_translate_usage();
+        cerr << "'-o' must be followed by a filename to write results to\n";
+        exit(1);
+      }
+      output_filename = argv[i];
+    }
+    else {
+      ifstream fin(argv[i]);
+      if (!fin) {
+        cerr << "could not open " << argv[i] << '\n';
+        return 1;
+      }
+      parse(fin, p);
+      if (trace_contains_errors()) return 1;
+    }
+  }
+  if (p.segments.empty()) {
+    print_translate_usage();
+    cerr << "nothing to do; must provide at least one file to read\n";
+    exit(1);
+  }
+  if (output_filename.empty()) {
+    print_translate_usage();
+    cerr << "must provide a filename to write to using '-o'\n";
+    exit(1);
   }
-  parse(fin, p);
-  if (trace_contains_errors()) return 1;
   transform(p);
   if (trace_contains_errors()) return 1;
-  save_elf(p, argv[3]);
+  save_elf(p, output_filename);
   if (trace_contains_errors()) {
-    unlink(argv[3]);
+    unlink(output_filename.c_str());
     return 1;
   }
   return 0;
 }
 
 :(code)
+void print_translate_usage() {
+  cerr << "Usage: subx translate <input.subx> -o <output_ELF>\n";
+}
+
 // write out a program to a bare-bones ELF file
-void save_elf(const program& p, const char* filename) {
-  ofstream out(filename, ios::binary);
+void save_elf(const program& p, const string& filename) {
+  ofstream out(filename.c_str(), ios::binary);
   write_elf_header(out, p);
   for (size_t i = 0;  i < p.segments.size();  ++i)
     write_segment(p.segments.at(i), out);