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

[Ian Romanick]

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

Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
---
 src/glsl/Makefile          |    1 +
 src/glsl/link_uniforms.cpp |  116 ++++++++++++++++++++++++++++++++++++++++++++
 src/glsl/linker.h          |   45 +++++++++++++++++
 3 files changed, 162 insertions(+), 0 deletions(-)
 create mode 100644 src/glsl/link_uniforms.cpp

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..38bc00c
--- /dev/null
+++ b/src/glsl/link_uniforms.cpp
@@ -0,0 +1,116 @@
+/*
+ * 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)
+{
+   char *name = const_cast<char *>(var->name);
+   unsigned len = 0;
+
+   recursion(var->type, &name, strlen(name), len);
+   if (name != var->name)
+      free(name);
+}
+
+void uniform_field_visitor::recursion(const glsl_type *t, char **name,
+				      unsigned name_length,
+				      unsigned &name_buffer_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 unsigned len = strlen(t->fields.structure[i].name);
+
+	 /* Size of "name.field\0".
+	  */
+	 const unsigned field_length = name_length + 1 + len + 1;
+
+	 /* Grow the name buffer if it is not large enough to hold the fully
+	  * qualified name of this field.
+	  */
+	 if (name_buffer_length < field_length) {
+	    if (name_buffer_length == 0) {
+	       name_buffer_length = field_length + 16;
+	       char *tmp = (char *) malloc(name_buffer_length);
+	       strcpy(tmp, *name);
+
+	       *name = tmp;
+	    } else {
+	       name_buffer_length = field_length + 16;
+	       *name = (char *) realloc(*name, name_buffer_length);
+	    }
+	 }
+
+	 /* Append '.field' to the current uniform name.
+	  */
+	 (*name)[name_length] = '.';
+	 memcpy(& (*name)[name_length+1], t->fields.structure[i].name, len);
+	 (*name)[field_length - 1] = '\0';
+
+	 recursion(t->fields.structure[i].type,
+		   name, field_length - 1, name_buffer_length);
+      }
+   } else if (t->is_array() && t->fields.array->is_record()) {
+      const unsigned extra = unsigned(ceil(log10(float(t->length)))) + 2;
+      const unsigned field_length = name_length + extra;
+
+      if (name_buffer_length < field_length) {
+	 if (name_buffer_length == 0) {
+	    name_buffer_length = field_length + 16;
+	    char *tmp = (char *) malloc(name_buffer_length);
+	    strcpy(tmp, *name);
+
+	    *name = tmp;
+	 } else {
+	    name_buffer_length = field_length + 16;
+	    *name = (char *) realloc(*name, name_buffer_length);
+	 }
+      }
+
+      for (unsigned i = 0; i < t->length; i++) {
+	 const unsigned len = name_length
+	    + sprintf(&(*name)[name_length], "[%d]", i);
+
+	 recursion(t->fields.array, name, len, name_buffer_length);
+      }
+   } else {
+      this->visit_field(t, *name);
+   }
+}
diff --git a/src/glsl/linker.h b/src/glsl/linker.h
index 769cf68..2bd2b47 100644
--- a/src/glsl/linker.h
+++ b/src/glsl/linker.h
@@ -1,3 +1,4 @@
+/* -*- c++ -*- */
 /*
  * Copyright © 2010 Intel Corporation
  *
@@ -29,4 +30,48 @@ 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,
+		  unsigned &name_buffer_length);
+};
+
 #endif /* GLSL_LINKER_H */
-- 
1.7.6.4