mesa/glsl: Separate parsing logic from _mesa_get_uniform_location.

The parsing logic is moved to a new function in the GLSL module,
parse_program_resource_name().  This name was chosen because it should
eventually be useful for handling everything that OpenGL 4.3 calls
"program resources" (e.g. uniforms, vertex inputs, fragment outputs,
and transform feedback varyings).

Future patches will make use of this function for linking transform
feedback varyings.

NOTE: This is a candidate for the 9.1 branch.

Reviewed-by: Jordan Justen <[email protected]>
Reviewed-by: Matt Turner <[email protected]>

2 files changed, 28 insertions, 61 deletions

diff --git a/src/mesa/main/uniform_query.cpp b/src/mesa/main/uniform_query.cpp
index dc550bc4324..b8335fe6bd8 100644
--- a/src/mesa/main/uniform_query.cpp
+++ b/src/mesa/main/uniform_query.cpp
@@ -929,6 +929,7 @@ _mesa_uniform_matrix(struct gl_context *ctx, struct gl_shader_program *shProg,
    _mesa_propagate_uniforms_to_driver_storage(uni, offset, count);
 }
 
+
 /**
  * Called via glGetUniformLocation().
  *
@@ -944,73 +945,35 @@ _mesa_get_uniform_location(struct gl_context *ctx,
                            const GLchar *name,
                            unsigned *out_offset)
 {
-   const size_t len = strlen(name);
-   long offset;
-   bool array_lookup;
-   char *name_copy;
-
-   /* If the name ends with a ']', assume that it refers to some element of an
-    * array.  Malformed array references will fail the hash table look up
-    * below, so it doesn't matter that they are not caught here.  This code
-    * only wants to catch the "leaf" array references so that arrays of
-    * structures containing arrays will be handled correctly.
+   /* Page 80 (page 94 of the PDF) of the OpenGL 2.1 spec says:
+    *
+    *     "The first element of a uniform array is identified using the
+    *     name of the uniform array appended with "[0]". Except if the last
+    *     part of the string name indicates a uniform array, then the
+    *     location of the first element of that array can be retrieved by
+    *     either using the name of the uniform array, or the name of the
+    *     uniform array appended with "[0]"."
+    *
+    * Note: since uniform names are not allowed to use whitespace, and array
+    * indices within uniform names are not allowed to use "+", "-", or leading
+    * zeros, it follows that each uniform has a unique name up to the possible
+    * ambiguity with "[0]" noted above.  Therefore we don't need to worry
+    * about mal-formed inputs--they will properly fail when we try to look up
+    * the uniform name in shProg->UniformHash.
     */
-   if (name[len-1] == ']') {
-      unsigned i;
-
-      /* Walk backwards over the string looking for a non-digit character.
-       * This had better be the opening bracket for an array index.
-       *
-       * Initially, i specifies the location of the ']'.  Since the string may
-       * contain only the ']' charcater, walk backwards very carefully.
-       */
-      for (i = len - 1; (i > 0) && isdigit(name[i-1]); --i)
-	 /* empty */ ;
-
-      /* Page 80 (page 94 of the PDF) of the OpenGL 2.1 spec says:
-       *
-       *     "The first element of a uniform array is identified using the
-       *     name of the uniform array appended with "[0]". Except if the last
-       *     part of the string name indicates a uniform array, then the
-       *     location of the first element of that array can be retrieved by
-       *     either using the name of the uniform array, or the name of the
-       *     uniform array appended with "[0]"."
-       *
-       * Page 79 (page 93 of the PDF) of the OpenGL 2.1 spec says:
-       *
-       *     "name must be a null terminated string, without white space."
-       *
-       * Return an error if there is no opening '[' to match the closing ']'.
-       * An error will also be returned if there is intervening white space
-       * (or other non-digit characters) before the opening '['.
-       */
-      if ((i == 0) || name[i-1] != '[')
-	 return GL_INVALID_INDEX;
 
-      /* Return an error if there are no digits between the opening '[' to
-       * match the closing ']'.
-       */
-      if (i == (len - 1))
-	 return GL_INVALID_INDEX;
-
-      /* Make a new string that is a copy of the old string up to (but not
-       * including) the '[' character.
-       */
-      name_copy = (char *) malloc(i);
-      memcpy(name_copy, name, i - 1);
-      name_copy[i-1] = '\0';
-
-      offset = strtol(&name[i], NULL, 10);
-      if (offset < 0) {
-	 free(name_copy);
-	 return GL_INVALID_INDEX;
-      }
+   const GLchar *base_name_end;
+   long offset = parse_program_resource_name(name, &base_name_end);
+   bool array_lookup = offset >= 0;
+   char *name_copy;
 
-      array_lookup = true;
+   if (array_lookup) {
+      name_copy = (char *) malloc(base_name_end - name + 1);
+      memcpy(name_copy, name, base_name_end - name);
+      name_copy[base_name_end - name] = '\0';
    } else {
       name_copy = (char *) name;
       offset = 0;
-      array_lookup = false;
    }
 
    unsigned location = 0;
diff --git a/src/mesa/main/uniforms.h b/src/mesa/main/uniforms.h
index f17503121c8..a12ad9b36f3 100644
--- a/src/mesa/main/uniforms.h
+++ b/src/mesa/main/uniforms.h
@@ -167,6 +167,10 @@ _mesa_GetActiveUniformsiv(GLuint program,
 void GLAPIENTRY
 _mesa_GetUniformiv(GLhandleARB, GLint, GLint *);
 
+long
+_mesa_parse_program_resource_name(const GLchar *name,
+                                  const GLchar **out_base_name_end);
+
 unsigned
 _mesa_get_uniform_location(struct gl_context *ctx, struct gl_shader_program *shProg,
 			   const GLchar *name, unsigned *offset);