[Mesa-dev] [PATCH 3/4 v2] linker: Add uniform_field_visitor class to process leaf fields of a uniform

[Kenneth Graunke]

From: Ian Romanick <ian.d.romanick at intel.com>

Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
---
 src/glsl/Makefile          |    1 +
 src/glsl/link_uniforms.cpp |   85 ++++++++++++++++++++++++++++++++++++++++++++
 src/glsl/linker.h          |   44 +++++++++++++++++++++++
 3 files changed, 130 insertions(+), 0 deletions(-)
 create mode 100644 src/glsl/link_uniforms.cpp

Tested with a newly updated Piglit.  I applied Ian's patch series and ran
the tests, then swapped out his 3/4 for this patch.  No changes.

This version doesn't use a const_cast<> and also pushed most of the string
munging into ralloc.  I find it easier to read.

diff --git a/src/glsl/Makefile b/src/glsl/Makefile
index b2efb2a..504f1fb 100644
--- a/src/glsl/Makefile
+++ b/src/glsl/Makefile
@@ -53,6 +53,7 @@ CXX_SOURCES = \
 	ir_variable_refcount.cpp \
 	linker.cpp \
 	link_functions.cpp \
+	link_uniforms.cpp \
 	loop_analysis.cpp \
 	loop_controls.cpp \
 	loop_unroll.cpp \
diff --git a/src/glsl/link_uniforms.cpp b/src/glsl/link_uniforms.cpp
new file mode 100644
index 0000000..6dd1f53
--- /dev/null
+++ b/src/glsl/link_uniforms.cpp
@@ -0,0 +1,85 @@
+/*
+ * 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.
+ */
+
+#include "main/core.h"
+#include "ir.h"
+#include "linker.h"
+#include "glsl_symbol_table.h"
+#include "program/hash_table.h"
+
+/**
+ * \file link_uniforms.cpp
+ * Assign locations for GLSL uniforms.
+ *
+ * \author Ian Romanick <ian.d.romanick at intel.com>
+ */
+
+void
+uniform_field_visitor::process(ir_variable *var)
+{
+   const glsl_type *t = var->type;
+
+   /* Only strdup the name if we actually will need to modify it. */
+   if (t->is_record() || (t->is_array() && t->fields.array->is_record())) {
+      char *name = ralloc_strdup(NULL, var->name);
+      recursion(var->type, &name, strlen(name));
+      ralloc_free(name);
+   } else {
+      this->visit_field(t, var->name);
+   }
+}
+
+void
+uniform_field_visitor::recursion(const glsl_type *t, char **name,
+				 unsigned name_length)
+{
+   /* Records need to have each field processed individually.
+    *
+    * Arrays of records need to have each array element processed
+    * individually, then each field of the resulting array elements processed
+    * individually.
+    */
+   if (t->is_record()) {
+      for (unsigned i = 0; i < t->length; i++) {
+	 const char *field = t->fields.structure[i].name;
+
+	 /* Append '.field' to the current uniform name. */
+	 ralloc_asprintf_rewrite_tail(name, name_length, ".%s", field);
+
+	 recursion(t->fields.structure[i].type, name,
+		   name_length + 1 + strlen(field));
+      }
+   } else if (t->is_array() && t->fields.array->is_record()) {
+      for (unsigned i = 0; i < t->length; i++) {
+	 char subscript[13];
+
+	 /* Append the subscript to the current uniform name */
+	 const unsigned subscript_length = snprintf(subscript, 13, "[%u]", i);
+	 ralloc_asprintf_rewrite_tail(name, name_length, "%s", subscript);
+
+	 recursion(t->fields.array, name, name_length + subscript_length);
+      }
+   } else {
+      this->visit_field(t, *name);
+   }
+}
diff --git a/src/glsl/linker.h b/src/glsl/linker.h
index 769cf68..c7452b1 100644
--- a/src/glsl/linker.h
+++ b/src/glsl/linker.h
@@ -1,3 +1,4 @@
+/* -*- c++ -*- */
 /*
  * Copyright © 2010 Intel Corporation
  *
@@ -29,4 +30,47 @@ extern bool
 link_function_calls(gl_shader_program *prog, gl_shader *main,
 		    gl_shader **shader_list, unsigned num_shaders);
 
+
+/**
+ * Class for processing all of the leaf fields of an uniform
+ *
+ * Leaves are, roughly speaking, the parts of the uniform that the application
+ * could query with \c glGetUniformLocation (or that could be returned by
+ * \c glGetActiveUniforms).
+ *
+ * Classes my derive from this class to implement specific functionality.
+ * This class only provides the mechanism to iterate over the leaves.  Derived
+ * classes must implement \c ::visit_field and may override \c ::process.
+ */
+class uniform_field_visitor {
+public:
+   /**
+    * Begin processing a uniform
+    *
+    * Classes that overload this function should call \c ::process from the
+    * base class to start the recursive processing of the uniform.
+    *
+    * \param var  The uniform variable that is to be processed
+    *
+    * Calls \c ::visit_field for each leaf of the uniform.
+    */
+   void process(ir_variable *var);
+
+protected:
+   /**
+    * Method invoked for each leaf of the uniform
+    *
+    * \param type  Type of the field.
+    * \param name  Fully qualified name of the field.
+    */
+   virtual void visit_field(const glsl_type *type, const char *name) = 0;
+
+private:
+   /**
+    * \param name_length  Length of the current name \b not including the
+    *                     terminating \c NUL character.
+    */
+   void recursion(const glsl_type *t, char **name, unsigned name_length);
+};
+
 #endif /* GLSL_LINKER_H */
-- 
1.7.7