linker: Add uniform_field_visitor class to process leaf fields of a uniform

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>

1 files changed, 43 insertions, 0 deletions

diff --git a/src/glsl/linker.h b/src/glsl/linker.h
index 769cf68b6ad..78c63296133 100644
--- a/src/glsl/linker.h
+++ b/src/glsl/linker.h
@@ -1,3 +1,4 @@
+/* -*- c++ -*- */
 /*
  * Copyright © 2010 Intel Corporation
  *
@@ -29,4 +30,46 @@ 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 */