glsl/tests: Verify vertex shader built-ins generated by _mesa_glsl_initialize_variables

Checks that the variables generated meet certain criteria.

 - Vertex shader inputs have an explicit location.

 - Vertex shader outputs have an explicit location.

 - Fragment shader-only varying locations are not used.

 - Vertex shader uniforms and system values don't have an explicit
   location.

 - Vertex shader constants don't have an explicit location and are
   read-only.

 - No other kinds of vertex variables exist.

It does not verify that an specific variables exist.

v2: Fix memory management mistakes in
common_builtin::string_starts_with_prefix.  Clean up error message
reporting in common_builtin::no_invalid_variable_modes.  Both suggested
by Paul.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Paul Berry <stereotype441@gmail.com>

src/glsl/Makefile.am

@@ -59,6 +59,7 @@ tests_general_ir_test_SOURCES =		\
 	$(top_srcdir)/src/mesa/program/prog_hash_table.c\
 	$(top_srcdir)/src/mesa/program/symbol_table.c	\
 	$(GLSL_SRCDIR)/standalone_scaffolding.cpp \
+	tests/builtin_variable_test.cpp			\
 	tests/general_ir_test.cpp
 tests_general_ir_test_CFLAGS =				\
 	$(PTHREAD_CFLAGS)

src/glsl/tests/builtin_variable_test.cpp

@@ -0,0 +1,224 @@
+/*
+ * Copyright © 2013 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.
+ */
+#include <gtest/gtest.h>
+#include "standalone_scaffolding.h"
+#include "main/compiler.h"
+#include "main/mtypes.h"
+#include "main/macros.h"
+#include "ralloc.h"
+#include "ir.h"
+#include "glsl_parser_extras.h"
+#include "glsl_symbol_table.h"
+
+class common_builtin : public ::testing::Test {
+public:
+   common_builtin(GLenum shader_type)
+      : shader_type(shader_type)
+   {
+      /* empty */
+   }
+
+   virtual void SetUp();
+   virtual void TearDown();
+
+   void string_starts_with_prefix(const char *str, const char *prefix);
+   void names_start_with_gl();
+   void uniforms_and_system_values_dont_have_explicit_location();
+   void constants_are_constant();
+   void no_invalid_variable_modes();
+
+   GLenum shader_type;
+   struct _mesa_glsl_parse_state *state;
+   struct gl_shader *shader;
+   void *mem_ctx;
+   gl_context ctx;
+   exec_list ir;
+};
+
+void
+common_builtin::SetUp()
+{
+   this->mem_ctx = ralloc_context(NULL);
+   this->ir.make_empty();
+
+   initialize_context_to_defaults(&this->ctx, API_OPENGL_COMPAT);
+
+   this->shader = rzalloc(this->mem_ctx, gl_shader);
+   this->shader->Type = this->shader_type;
+
+   this->state =
+      new(mem_ctx) _mesa_glsl_parse_state(&this->ctx, this->shader->Type,
+                                          this->shader);
+
+   _mesa_glsl_initialize_types(this->state);
+   _mesa_glsl_initialize_variables(&this->ir, this->state);
+}
+
+void
+common_builtin::TearDown()
+{
+   ralloc_free(this->mem_ctx);
+   this->mem_ctx = NULL;
+}
+
+void
+common_builtin::string_starts_with_prefix(const char *str, const char *prefix)
+{
+   const size_t len = strlen(prefix);
+   char *const name_prefix = new char[len + 1];
+
+   strncpy(name_prefix, str, len);
+   name_prefix[len] = '\0';
+   EXPECT_STREQ(prefix, name_prefix) << "Bad name " << str;
+
+   delete [] name_prefix;
+}
+
+void
+common_builtin::names_start_with_gl()
+{
+   foreach_list(node, &this->ir) {
+      ir_variable *const var = ((ir_instruction *) node)->as_variable();
+
+      string_starts_with_prefix(var->name, "gl_");
+   }
+}
+
+void
+common_builtin::uniforms_and_system_values_dont_have_explicit_location()
+{
+   foreach_list(node, &this->ir) {
+      ir_variable *const var = ((ir_instruction *) node)->as_variable();
+
+      if (var->mode != ir_var_uniform && var->mode != ir_var_system_value)
+         continue;
+
+      EXPECT_FALSE(var->explicit_location);
+      EXPECT_EQ(-1, var->location);
+   }
+}
+
+void
+common_builtin::constants_are_constant()
+{
+   foreach_list(node, &this->ir) {
+      ir_variable *const var = ((ir_instruction *) node)->as_variable();
+
+      if (var->mode != ir_var_auto)
+         continue;
+
+      EXPECT_FALSE(var->explicit_location);
+      EXPECT_EQ(-1, var->location);
+      EXPECT_TRUE(var->read_only);
+   }
+}
+
+void
+common_builtin::no_invalid_variable_modes()
+{
+   foreach_list(node, &this->ir) {
+      ir_variable *const var = ((ir_instruction *) node)->as_variable();
+
+      switch (var->mode) {
+      case ir_var_auto:
+      case ir_var_uniform:
+      case ir_var_shader_in:
+      case ir_var_shader_out:
+      case ir_var_system_value:
+         break;
+
+      default:
+         ADD_FAILURE() << "Built-in variable " << var->name
+                       << " has an invalid mode " << int(var->mode);
+         break;
+      }
+   }
+}
+
+/************************************************************/
+
+class vertex_builtin : public common_builtin {
+public:
+   vertex_builtin()
+      : common_builtin(GL_VERTEX_SHADER)
+   {
+      /* empty */
+   }
+};
+
+TEST_F(vertex_builtin, names_start_with_gl)
+{
+   common_builtin::names_start_with_gl();
+}
+
+TEST_F(vertex_builtin, inputs_have_explicit_location)
+{
+   foreach_list(node, &this->ir) {
+      ir_variable *const var = ((ir_instruction *) node)->as_variable();
+
+      if (var->mode != ir_var_shader_in)
+         continue;
+
+      EXPECT_TRUE(var->explicit_location);
+      EXPECT_NE(-1, var->location);
+      EXPECT_GT(VERT_ATTRIB_GENERIC0, var->location);
+      EXPECT_EQ(0u, var->location_frac);
+   }
+}
+
+TEST_F(vertex_builtin, outputs_have_explicit_location)
+{
+   foreach_list(node, &this->ir) {
+      ir_variable *const var = ((ir_instruction *) node)->as_variable();
+
+      if (var->mode != ir_var_shader_out)
+         continue;
+
+      EXPECT_TRUE(var->explicit_location);
+      EXPECT_NE(-1, var->location);
+      EXPECT_GT(VARYING_SLOT_VAR0, var->location);
+      EXPECT_EQ(0u, var->location_frac);
+
+      /* Several varyings only exist in the fragment shader.  Be sure that no
+       * outputs with these locations exist.
+       */
+      EXPECT_NE(VARYING_SLOT_PNTC, var->location);
+      EXPECT_NE(VARYING_SLOT_FACE, var->location);
+      EXPECT_NE(VARYING_SLOT_PRIMITIVE_ID, var->location);
+   }
+}
+
+TEST_F(vertex_builtin, uniforms_and_system_values_dont_have_explicit_location)
+{
+   common_builtin::uniforms_and_system_values_dont_have_explicit_location();
+}
+
+TEST_F(vertex_builtin, constants_are_constant)
+{
+   common_builtin::constants_are_constant();
+}
+
+TEST_F(vertex_builtin, no_invalid_variable_modes)
+{
+   common_builtin::no_invalid_variable_modes();
+}