mesa: Move _mesa_GetAttribLocationARB to shader_query.cpp

This allows querying the linked shader itself rather than the Mesa IR.
This is the first step towards removing gl_program::Attributes.

Signed-off-by: Ian Romanick <[email protected]>
Reviewed-by: Kenneth Graunke <[email protected]>

1 files changed, 88 insertions, 0 deletions

diff --git a/src/mesa/main/shader_query.cpp b/src/mesa/main/shader_query.cpp
new file mode 100644
index 00000000000..d5c1546967e
--- /dev/null
+++ b/src/mesa/main/shader_query.cpp
@@ -0,0 +1,88 @@
+/*
+ * Copyright © 2011 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+/**
+ * \file shader_query.cpp
+ * C-to-C++ bridge functions to query GLSL shader data
+ *
+ * \author Ian Romanick <[email protected]>
+ */
+
+#include "main/core.h"
+#include "glsl_symbol_table.h"
+#include "ir.h"
+#include "shaderobj.h"
+
+extern "C" {
+#include "shaderapi.h"
+}
+
+GLint GLAPIENTRY
+_mesa_GetAttribLocationARB(GLhandleARB program, const GLcharARB * name)
+{
+   GET_CURRENT_CONTEXT(ctx);
+   struct gl_shader_program *const shProg =
+      _mesa_lookup_shader_program_err(ctx, program, "glGetAttribLocation");
+
+   if (!shProg) {
+      return -1;
+   }
+
+   if (!shProg->LinkStatus) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+                  "glGetAttribLocation(program not linked)");
+      return -1;
+   }
+
+   if (!name)
+      return -1;
+
+   /* Not having a vertex shader is not an error.
+    */
+   if (shProg->_LinkedShaders[MESA_SHADER_VERTEX] == NULL)
+      return -1;
+
+   exec_list *ir = shProg->_LinkedShaders[MESA_SHADER_VERTEX]->ir;
+   foreach_list(node, ir) {
+      const ir_variable *const var = ((ir_instruction *) node)->as_variable();
+
+      /* The extra check against VERT_ATTRIB_GENERIC0 is because
+       * glGetAttribLocation cannot be used on "conventional" attributes.
+       *
+       * From page 95 of the OpenGL 3.0 spec:
+       *
+       *     "If name is not an active attribute, if name is a conventional
+       *     attribute, or if an error occurs, -1 will be returned."
+       */
+      if (var == NULL
+	  || var->mode != ir_var_in
+	  || var->location == -1
+	  || var->location < VERT_ATTRIB_GENERIC0)
+	 continue;
+
+      if (strcmp(var->name, name) == 0)
+	 return var->location - VERT_ATTRIB_GENERIC0;
+   }
+
+   return -1;
+}