1 files changed, 66 insertions, 5 deletions

diff --git a/src/mesa/main/shader_query.cpp b/src/mesa/main/shader_query.cpp
index f66c117338c..36d1d9cc025 100644
--- a/src/mesa/main/shader_query.cpp
+++ b/src/mesa/main/shader_query.cpp
@@ -153,6 +153,63 @@ _mesa_GetActiveAttrib(GLhandleARB program, GLuint desired_index,
    _mesa_error(ctx, GL_INVALID_VALUE, "glGetActiveAttrib(index)");
 }
 
+/* Locations associated with shader variables (array or non-array) can be
+ * queried using its base name or using the base name appended with the
+ * valid array index. For example, in case of below vertex shader, valid
+ * queries can be made to know the location of "xyz", "array", "array[0]",
+ * "array[1]", "array[2]" and "array[3]". In this example index reurned
+ * will be 0, 0, 0, 1, 2, 3 respectively.
+ *
+ * [Vertex Shader]
+ * layout(location=0) in vec4 xyz;
+ * layout(location=1) in vec4[4] array;
+ * void main()
+ * { }
+ *
+ * This requirement came up with the addition of ARB_program_interface_query
+ * to OpenGL 4.3 specification. See page 101 (page 122 of the PDF) for details.
+ *
+ * This utility function is used by:
+ * _mesa_GetAttribLocation
+ * _mesa_GetFragDataLocation
+ * _mesa_GetFragDataIndex
+ *
+ * Returns 0:
+ *    if the 'name' string matches var->name.
+ * Returns 'matched index':
+ *    if the 'name' string matches var->name appended with valid array index.
+ */
+int static inline
+get_matching_index(const ir_variable *const var, const char *name) {
+   unsigned idx = 0;
+   const char *const paren = strchr(name, '[');
+   const unsigned len = (paren != NULL) ? paren - name : strlen(name);
+
+   if (paren != NULL) {
+      if (!var->type->is_array())
+         return -1;
+
+      char *endptr;
+      idx = (unsigned) strtol(paren + 1, &endptr, 10);
+      const unsigned idx_len = endptr != (paren + 1) ? endptr - paren - 1 : 0;
+
+      /* Validate the sub string representing index in 'name' string */
+      if ((idx > 0 && paren[1] == '0') /* leading zeroes */
+          || (idx == 0 && idx_len > 1) /* all zeroes */
+          || paren[1] == ' ' /* whitespace */
+          || endptr[0] != ']' /* closing brace */
+          || endptr[1] != '\0' /* null char */
+          || idx_len == 0 /* missing index */
+          || idx >= var->type->length) /* exceeding array bound */
+         return -1;
+   }
+
+   if (strncmp(var->name, name, len) == 0 && var->name[len] == '\0')
+      return idx;
+
+   return -1;
+}
+
 GLint GLAPIENTRY
 _mesa_GetAttribLocation(GLhandleARB program, const GLcharARB * name)
 {
@@ -196,8 +253,10 @@ _mesa_GetAttribLocation(GLhandleARB program, const GLcharARB * name)
 	  || var->data.location < VERT_ATTRIB_GENERIC0)
 	 continue;
 
-      if (strcmp(var->name, name) == 0)
-	 return var->data.location - VERT_ATTRIB_GENERIC0;
+      int index = get_matching_index(var, (const char *) name);
+
+      if (index >= 0)
+         return var->data.location + index - VERT_ATTRIB_GENERIC0;
    }
 
    return -1;
@@ -358,7 +417,7 @@ _mesa_GetFragDataIndex(GLuint program, const GLchar *name)
           || var->data.location < FRAG_RESULT_DATA0)
          continue;
 
-      if (strcmp(var->name, name) == 0)
+      if (get_matching_index(var, (const char *) name) >= 0)
          return var->data.index;
    }
 
@@ -414,8 +473,10 @@ _mesa_GetFragDataLocation(GLuint program, const GLchar *name)
 	  || var->data.location < FRAG_RESULT_DATA0)
 	 continue;
 
-      if (strcmp(var->name, name) == 0)
-	 return var->data.location - FRAG_RESULT_DATA0;
+      int index = get_matching_index(var, (const char *) name);
+
+      if (index >= 0)
+         return var->data.location + index - FRAG_RESULT_DATA0;
    }
 
    return -1;