Simplified parameter parsing to have all shader formats use the same slang method

(when HAVE_SLANG and HAVE_SPIRV_CROSS are defined) - backport of HyperSpaceMadness' PR

gfx/drivers_shader/glslang_util.c

@@ -150,9 +150,9 @@ bool glslang_read_shader_file(const char *path,
    if (lines.size < 1)
       goto error;
 
-   /* If this is the 'parent' shader file, ensure that first
-    * line is a 'VERSION' string */
-   if (root_file)
+    /* If this is the 'parent' shader file and a slang file,
+    * ensure that first line is a 'VERSION' string */
+   if (root_file && string_is_equal(path_get_extension(path), "slang"))
    {
       const char *line = lines.elems[0].data;
 
@@ -166,9 +166,9 @@ bool glslang_read_shader_file(const char *path,
       if (!string_list_append(output, line, attr))
          goto error;
 
-      /* Allows us to use #line to make dealing with shader 
+      /* Allows us to use #line to make dealing with shader
        * errors easier.
-       * This is supported by glslang, but since we always 
+       * This is supported by glslang, but since we always
        * use glslang statically, this is fine. */
       if (!string_list_append(output,
                "#extension GL_GOOGLE_cpp_style_line_directive : require",

gfx/drivers_shader/glslang_util.h

@@ -120,6 +120,14 @@ const char *glslang_format_to_string(glslang_format fmt);
 
 enum glslang_format glslang_find_format(const char *fmt);
 
+/* Reads a shader file and outputs its contents as a string list.
+   Takes the path of the shader file and appends each line of the file
+   to the output string list.
+   If the root_file argument is set to true, it expects the first line of the file
+   to be a valid '#version' string
+   Handles '#include' statements by recursively parsing included files and appending their contents.
+   Returns a Bool indicating if parsing was successful.
+ */
 bool glslang_read_shader_file(const char *path,
       struct string_list *output, bool root_file);
 

gfx/video_shader_parse.c

@@ -870,28 +870,15 @@ void video_shader_resolve_parameters(struct video_shader *shader)
       uint8_t *buf              = NULL;
       int64_t buf_len           = 0;
 
-      if (string_is_empty(path))
+      if (string_is_empty(path) || !path_is_valid(path))
          continue;
 
-      if (!path_is_valid(path))
-         continue;
-
-      /* First try to use the more robust slang implementation
-       * to support #includes. */
-
 #if defined(HAVE_SLANG) && defined(HAVE_SPIRV_CROSS)
-      /* FIXME: The check for slang can be removed
-       * if it's sufficiently tested for GLSL/Cg as well,
-       * it should be the same implementation.
-       * The problem with switching currently is that it looks
-       * for a #version string in the first line of the file
-       * which glsl doesn't have */
-
-      if (     string_is_equal(path_get_extension(path), "slang")
-            && slang_preprocess_parse_parameters(path, shader))
-         continue;
-#endif
-
+      /* Now uses the same slang parsing for parameters since
+       * it should be the same implementation, but supporting
+       * #include directives */
+      slang_preprocess_parse_parameters(path, shader);
+#else
       /* Read file contents */
       if (filestream_read_file(path, (void**)&buf, &buf_len))
       {
@@ -956,6 +943,7 @@ void video_shader_resolve_parameters(struct video_shader *shader)
 
          string_list_deinitialize(&lines);
       }
+#endif
    }
 }