From 5fc9b139df6d93d014654c9acbc5d42aede3bb0c Mon Sep 17 00:00:00 2001
From: Jason Ekstrand <jason@jlekstrand.net>
Date: Fri, 4 Sep 2020 17:14:39 -0500
Subject: [PATCH] spirv2nir: Rework argument handling

The argument handling of this little tool was pretty rubbish.  It had no
help and it required the filename to come first which is just strange.
This reworks it and makes things much nicer.  It's still rubbish but at
least there's a chance people can figure out how to use it now.

Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6607>
---
 src/compiler/spirv/spirv2nir.c | 53 ++++++++++++++++++++++++----------
 1 file changed, 37 insertions(+), 16 deletions(-)

diff --git a/src/compiler/spirv/spirv2nir.c b/src/compiler/spirv/spirv2nir.c
index bbec4d2af6a..c6dfab0d366 100644
--- a/src/compiler/spirv/spirv2nir.c
+++ b/src/compiler/spirv/spirv2nir.c
@@ -65,6 +65,20 @@ stage_to_enum(char *stage)
       return MESA_SHADER_NONE;
 }
 
+static void
+print_usage(char *exec_name, FILE *f)
+{
+   fprintf(f,
+"Usage: %s [options] file\n"
+"Options:\n"
+"  -h  --help              Print this help.\n"
+"  -s, --stage <stage>     Specify the shader stage.  Valid stages are:\n"
+"                          vertex, tess-ctrl, tess-eval, geometry, fragment,\n"
+"                          compute, and kernel (OpenCL-style compute).\n"
+"  -e, --entry <name>      Specify the entry-point name.\n"
+   , exec_name);
+}
+
 int main(int argc, char **argv)
 {
    gl_shader_stage shader_stage = MESA_SHADER_FRAGMENT;
@@ -73,36 +87,43 @@ int main(int argc, char **argv)
 
    static struct option long_options[] =
      {
+       {"help",         no_argument, 0, 'h'},
        {"stage",  required_argument, 0, 's'},
        {"entry",  required_argument, 0, 'e'},
        {0, 0, 0, 0}
      };
 
-   while ((ch = getopt_long(argc - 1, argv + 1, "s:e:", long_options, NULL)) != -1)
+   while ((ch = getopt_long(argc, argv, "hs:e:", long_options, NULL)) != -1)
    {
       switch (ch)
       {
-         case 's':
-            shader_stage = stage_to_enum(optarg);
-            if (shader_stage == MESA_SHADER_NONE)
-            {
-               fprintf(stderr, "Unknown stage %s\n", optarg);
-               return 1;
-            }
-            break;
-         case 'e':
-            entry_point = optarg;
-            break;
-         default:
-            fprintf(stderr, "Unrecognized option.\n");
+      case 'h':
+         print_usage(argv[0], stdout);
+         return 0;
+      case 's':
+         shader_stage = stage_to_enum(optarg);
+         if (shader_stage == MESA_SHADER_NONE)
+         {
+            fprintf(stderr, "Unknown stage \"%s\"\n", optarg);
+            print_usage(argv[0], stderr);
             return 1;
+         }
+         break;
+      case 'e':
+         entry_point = optarg;
+         break;
+      default:
+         fprintf(stderr, "Unrecognized option \"%s\".\n", optarg);
+         print_usage(argv[0], stderr);
+         return 1;
       }
    }
 
-   int fd = open(argv[1], O_RDONLY);
+   const char *filename = argv[optind];
+   int fd = open(filename, O_RDONLY);
    if (fd < 0)
    {
-      fprintf(stderr, "Failed to open %s\n", argv[1]);
+      fprintf(stderr, "Failed to open %s\n", filename);
       return 1;
    }
 
-- 
2.30.2