Add ir_hierarchical_visitor base class and associated infrastructure

This type of visitor should eventually replace all or almost all
current uses of ir_visitor.

5 files changed, 615 insertions, 1 deletions

diff --git a/Makefile.am b/Makefile.am
index 105fcc5..aa05021 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -46,7 +46,10 @@ glsl_SOURCES = \
 	ir_optimization.h \
 	ir_reader.cpp s_expression.cpp \
 	ir_visit_tree.cpp \
-	ir_visit_tree.h
+	ir_visit_tree.h \
+	ir_hv_accept.cpp \
+	ir_hierarchical_visitor.h \
+	ir_hierarchical_visitor.cpp
 
 BUILT_SOURCES = glsl_parser.h glsl_parser.cpp glsl_lexer.cpp
 CLEANFILES = $(BUILT_SOURCES)
diff --git a/ir.h b/ir.h
index a533eee..93b4c2b 100644
--- a/ir.h
+++ b/ir.h
@@ -28,6 +28,7 @@
 
 #include "list.h"
 #include "ir_visitor.h"
+#include "ir_hierarchical_visitor.h"
 
 struct ir_program {
    void *bong_hits;
@@ -42,6 +43,7 @@ public:
 
    class ir_constant *constant_expression_value();
    virtual void accept(ir_visitor *) = 0;
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *) = 0;
 
    /**
     * \name IR instruction downcast functions
@@ -130,6 +132,8 @@ public:
       v->visit(this);
    }
 
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
    /**
     * Duplicate an IR variable
     *
@@ -210,6 +214,8 @@ public:
       v->visit(this);
    }
 
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
    /**
     * Get the name of the function for which this is a signature
     */
@@ -277,6 +283,8 @@ public:
       v->visit(this);
    }
 
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
    void add_signature(ir_function_signature *sig)
    {
       sig->function = this;
@@ -343,6 +351,8 @@ public:
       v->visit(this);
    }
 
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
    ir_rvalue *condition;
    /** List of ir_instruction for the body of the then branch */
    exec_list  then_instructions;
@@ -366,6 +376,8 @@ public:
       v->visit(this);
    }
 
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
    virtual ir_loop *as_loop()
    {
       return this;
@@ -403,6 +415,8 @@ public:
       v->visit(this);
    }
 
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
    virtual ir_assignment * as_assignment()
    {
       return this;
@@ -531,6 +545,8 @@ public:
       v->visit(this);
    }
 
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
    ir_expression *clone();
 
    ir_expression_operation operation;
@@ -561,6 +577,8 @@ public:
       v->visit(this);
    }
 
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
    /**
     * Get a generic ir_call object when an error occurs
     */
@@ -650,6 +668,8 @@ public:
       v->visit(this);
    }
 
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
 private:
    ir_rvalue *value;
 };
@@ -681,6 +701,8 @@ public:
       v->visit(this);
    }
 
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
    bool is_break() const
    {
       return mode == jump_break;
@@ -747,6 +769,8 @@ public:
       v->visit(this);
    }
 
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
    bool is_lvalue()
    {
       return val->is_lvalue() && !mask.has_duplicates;
@@ -780,6 +804,8 @@ public:
       v->visit(this);
    }
 
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
    bool is_lvalue();
 
    /**
@@ -825,6 +851,8 @@ public:
       v->visit(this);
    }
 
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
    ir_constant *clone()
    {
       return new ir_constant(this->type, &this->value);
diff --git a/ir_hierarchical_visitor.cpp b/ir_hierarchical_visitor.cpp
new file mode 100644
index 0000000..4fec0d7
--- /dev/null
+++ b/ir_hierarchical_visitor.cpp
@@ -0,0 +1,197 @@
+/*
+ * Copyright © 2010 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.
+ */
+#define NULL 0
+#include "ir.h"
+#include "ir_hierarchical_visitor.h"
+
+ir_visitor_status
+ir_hierarchical_visitor::visit(ir_variable *ir)
+{
+   (void) ir;
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_hierarchical_visitor::visit(ir_constant *ir)
+{
+   (void) ir;
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_hierarchical_visitor::visit(ir_loop_jump *ir)
+{
+   (void) ir;
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_hierarchical_visitor::visit_enter(ir_loop *ir)
+{
+   (void) ir;
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_hierarchical_visitor::visit_leave(ir_loop *ir)
+{
+   (void) ir;
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_hierarchical_visitor::visit_enter(ir_function_signature *ir)
+{
+   (void) ir;
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_hierarchical_visitor::visit_leave(ir_function_signature *ir)
+{
+   (void) ir;
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_hierarchical_visitor::visit_enter(ir_function *ir)
+{
+   (void) ir;
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_hierarchical_visitor::visit_leave(ir_function *ir)
+{
+   (void) ir;
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_hierarchical_visitor::visit_enter(ir_expression *ir)
+{
+   (void) ir;
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_hierarchical_visitor::visit_leave(ir_expression *ir)
+{
+   (void) ir;
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_hierarchical_visitor::visit_enter(ir_swizzle *ir)
+{
+   (void) ir;
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_hierarchical_visitor::visit_leave(ir_swizzle *ir)
+{
+   (void) ir;
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_hierarchical_visitor::visit_enter(ir_dereference *ir)
+{
+   (void) ir;
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_hierarchical_visitor::visit_leave(ir_dereference *ir)
+{
+   (void) ir;
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_hierarchical_visitor::visit_enter(ir_assignment *ir)
+{
+   (void) ir;
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_hierarchical_visitor::visit_leave(ir_assignment *ir)
+{
+   (void) ir;
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_hierarchical_visitor::visit_enter(ir_call *ir)
+{
+   (void) ir;
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_hierarchical_visitor::visit_leave(ir_call *ir)
+{
+   (void) ir;
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_hierarchical_visitor::visit_enter(ir_return *ir)
+{
+   (void) ir;
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_hierarchical_visitor::visit_leave(ir_return *ir)
+{
+   (void) ir;
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_hierarchical_visitor::visit_enter(ir_if *ir)
+{
+   (void) ir;
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_hierarchical_visitor::visit_leave(ir_if *ir)
+{
+   (void) ir;
+   return visit_continue;
+}
+
+void
+ir_hierarchical_visitor::run(exec_list *instructions)
+{
+   foreach_list(n, instructions) {
+      ir_instruction *ir = (ir_instruction *) n;
+
+      if (ir->accept(this) != visit_continue)
+	 break;
+   }
+}
diff --git a/ir_hierarchical_visitor.h b/ir_hierarchical_visitor.h
new file mode 100644
index 0000000..daf2209
--- /dev/null
+++ b/ir_hierarchical_visitor.h
@@ -0,0 +1,121 @@
+/* -*- c++ -*- */
+/*
+ * Copyright © 2010 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.
+ */
+
+#pragma once
+#ifndef IR_HIERARCHICAL_VISITOR_H
+#define IR_HIERARCHICAL_VISITOR_H
+
+/**
+ * Enumeration values returned by visit methods to guide processing
+ */
+enum ir_visitor_status {
+   visit_continue,		/**< Continue visiting as normal. */
+   visit_continue_with_parent,	/**< Don't visit siblings, continue w/parent. */
+   visit_stop			/**< Stop visiting immediately. */
+};
+
+
+/**
+ * Base class of hierarchical visitors of IR instruction trees
+ *
+ * Hierarchical visitors differ from traditional visitors in a couple of
+ * important ways.  Rather than having a single \c visit method for each
+ * subclass in the composite, there are three kinds of visit methods.
+ * Leaf-node classes have a traditional \c visit method.  Internal-node
+ * classes have a \c visit_enter method, which is invoked just before
+ * processing child nodes, and a \c visit_leave method which is invoked just
+ * after processing child nodes.
+ *
+ * In addition, each visit method and the \c accept methods in the composite
+ * have a return value which guides the navigation.  Any of the visit methods
+ * can choose to continue visiting the tree as normal (by returning \c
+ * visit_continue), terminate visiting any further nodes immediately (by
+ * returning \c visit_stop), or stop visiting sibling nodes (by returning \c
+ * visit_continue_with_parent).
+ *
+ * These two changes combine to allow nagivation of children to be implemented
+ * in the composite's \c accept method.  The \c accept method for a leaf-node
+ * class will simply call the \c visit method, as usual, and pass its return
+ * value on.  The \c accept method for internal-node classes will call the \c
+ * visit_enter method, call the \c accpet method of each child node, and,
+ * finally, call the \c visit_leave method.  If any of these return a value
+ * other that \c visit_continue, the correct action must be taken.
+ *
+ * The final benefit is that the hierarchical visitor base class need not be
+ * abstract.  Default implementations of every \c visit, \c visit_enter, and
+ * \c visit_leave method can be provided.  By default each of these methods
+ * simply returns \c visit_continue.  This allows a significant reduction in
+ * derived class code.
+ *
+ * For more information about hierarchical visitors, see:
+ *
+ *    http://c2.com/cgi/wiki?HierarchicalVisitorPattern
+ *    http://c2.com/cgi/wiki?HierarchicalVisitorDiscussion
+ */
+
+class ir_hierarchical_visitor {
+public:
+   /**
+    * \name Visit methods for leaf-node classes
+    */
+   /*@{*/
+   virtual ir_visitor_status visit(class ir_variable *);
+   virtual ir_visitor_status visit(class ir_constant *);
+   virtual ir_visitor_status visit(class ir_loop_jump *);
+   /*@}*/
+
+   /**
+    * \name Visit methods for internal-node classes
+    */
+   /*@{*/
+   virtual ir_visitor_status visit_enter(class ir_loop *);
+   virtual ir_visitor_status visit_leave(class ir_loop *);
+   virtual ir_visitor_status visit_enter(class ir_function_signature *);
+   virtual ir_visitor_status visit_leave(class ir_function_signature *);
+   virtual ir_visitor_status visit_enter(class ir_function *);
+   virtual ir_visitor_status visit_leave(class ir_function *);
+   virtual ir_visitor_status visit_enter(class ir_expression *);
+   virtual ir_visitor_status visit_leave(class ir_expression *);
+   virtual ir_visitor_status visit_enter(class ir_swizzle *);
+   virtual ir_visitor_status visit_leave(class ir_swizzle *);
+   virtual ir_visitor_status visit_enter(class ir_dereference *);
+   virtual ir_visitor_status visit_leave(class ir_dereference *);
+   virtual ir_visitor_status visit_enter(class ir_assignment *);
+   virtual ir_visitor_status visit_leave(class ir_assignment *);
+   virtual ir_visitor_status visit_enter(class ir_call *);
+   virtual ir_visitor_status visit_leave(class ir_call *);
+   virtual ir_visitor_status visit_enter(class ir_return *);
+   virtual ir_visitor_status visit_leave(class ir_return *);
+   virtual ir_visitor_status visit_enter(class ir_if *);
+   virtual ir_visitor_status visit_leave(class ir_if *);
+   /*@}*/
+
+
+   /**
+    * Utility function to process a linked list of instructions with a visitor
+    */
+   void run(struct exec_list *instructions);
+};
+
+#endif /* IR_HIERARCHICAL_VISITOR_H */
diff --git a/ir_hv_accept.cpp b/ir_hv_accept.cpp
new file mode 100644
index 0000000..7249bdb
--- /dev/null
+++ b/ir_hv_accept.cpp
@@ -0,0 +1,265 @@
+/*
+ * Copyright © 2010 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.
+ */
+#define NULL 0
+#include "ir.h"
+
+/**
+ * \file ir_hv_accept.cpp
+ * Implementations of all hierarchical visitor accept methods for IR
+ * instructions.
+ */
+
+/**
+ * Process a list of nodes using a hierarchical vistor
+ */
+static ir_visitor_status
+visit_list_elements(ir_hierarchical_visitor *v, exec_list *l)
+{
+   foreach_list (n, l) {
+      ir_instruction *const ir = (ir_instruction *) n;
+      ir_visitor_status s = ir->accept(v);
+
+      if (s != visit_continue)
+	 return s;
+   }
+
+   return visit_continue;
+}
+
+
+ir_visitor_status
+ir_variable::accept(ir_hierarchical_visitor *v)
+{
+   return v->visit(this);
+}
+
+
+ir_visitor_status
+ir_loop::accept(ir_hierarchical_visitor *v)
+{
+   ir_visitor_status s = v->visit_enter(this);
+
+   if (s != visit_continue)
+      return (s == visit_continue_with_parent) ? visit_continue : s;
+
+   s = visit_list_elements(v, &this->body_instructions);
+   if (s == visit_stop)
+      return s;
+
+   if (s != visit_continue_with_parent) {
+      if (this->from) {
+	 s = this->from->accept(v);
+	 if (s != visit_continue)
+	    return (s == visit_continue_with_parent) ? visit_continue : s;
+      }
+
+      if (this->to) {
+	 s = this->to->accept(v);
+	 if (s != visit_continue)
+	    return (s == visit_continue_with_parent) ? visit_continue : s;
+      }
+
+      if (this->increment) {
+	 s = this->increment->accept(v);
+	 if (s != visit_continue)
+	    return (s == visit_continue_with_parent) ? visit_continue : s;
+      }
+   }
+
+   return v->visit_leave(this);
+}
+
+
+ir_visitor_status
+ir_loop_jump::accept(ir_hierarchical_visitor *v)
+{
+   return v->visit(this);
+}
+
+
+ir_visitor_status
+ir_function_signature::accept(ir_hierarchical_visitor *v)
+{
+   ir_visitor_status s = v->visit_enter(this);
+   if (s != visit_continue)
+      return (s == visit_continue_with_parent) ? visit_continue : s;
+
+   s = visit_list_elements(v, &this->body);
+   return (s == visit_stop) ? s : v->visit_leave(this);
+}
+
+
+ir_visitor_status
+ir_function::accept(ir_hierarchical_visitor *v)
+{
+   /* FINISHME: Do we want to walk into functions? */
+   (void) v;
+   return visit_continue;
+}
+
+
+ir_visitor_status
+ir_expression::accept(ir_hierarchical_visitor *v)
+{
+   ir_visitor_status s = v->visit_enter(this);
+
+   if (s != visit_continue)
+      return (s == visit_continue_with_parent) ? visit_continue : s;
+
+   for (unsigned i = 0; i < this->get_num_operands(); i++) {
+      switch (this->operands[i]->accept(v)) {
+      case visit_continue:
+	 break;
+
+      case visit_continue_with_parent:
+	 // I wish for Java's labeled break-statement here.
+	 goto done;
+
+      case visit_stop:
+	 return s;
+      }
+   }
+
+done:
+   return v->visit_leave(this);
+}
+
+
+ir_visitor_status
+ir_swizzle::accept(ir_hierarchical_visitor *v)
+{
+   ir_visitor_status s = v->visit_enter(this);
+   if (s != visit_continue)
+      return (s == visit_continue_with_parent) ? visit_continue : s;
+
+   s = this->val->accept(v);
+   return (s == visit_stop) ? s : v->visit_leave(this);
+}
+
+
+ir_visitor_status
+ir_dereference::accept(ir_hierarchical_visitor *v)
+{
+   ir_visitor_status s = v->visit_enter(this);
+   if (s != visit_continue)
+      return (s == visit_continue_with_parent) ? visit_continue : s;
+
+   if (this->mode == ir_reference_array) {
+      s = this->selector.array_index->accept(v);
+      if (s != visit_continue)
+	 return (s == visit_continue_with_parent) ? visit_continue : s;
+   }
+
+
+   s = this->var->accept(v);
+   return (s == visit_stop) ? s : v->visit_leave(this);
+}
+
+
+ir_visitor_status
+ir_assignment::accept(ir_hierarchical_visitor *v)
+{
+   ir_visitor_status s = v->visit_enter(this);
+   if (s != visit_continue)
+      return (s == visit_continue_with_parent) ? visit_continue : s;
+
+   s = this->lhs->accept(v);
+   if (s != visit_continue)
+      return (s == visit_continue_with_parent) ? visit_continue : s;
+
+   s = this->rhs->accept(v);
+   if (s != visit_continue)
+      return (s == visit_continue_with_parent) ? visit_continue : s;
+
+   if (this->condition)
+      s = this->condition->accept(v);
+
+   return (s == visit_stop) ? s : v->visit_leave(this);
+}
+
+
+ir_visitor_status
+ir_constant::accept(ir_hierarchical_visitor *v)
+{
+   return v->visit(this);
+}
+
+
+ir_visitor_status
+ir_call::accept(ir_hierarchical_visitor *v)
+{
+   ir_visitor_status s = v->visit_enter(this);
+   if (s != visit_continue)
+      return (s == visit_continue_with_parent) ? visit_continue : s;
+
+   s = visit_list_elements(v, &this->actual_parameters);
+   if (s == visit_stop)
+      return s;
+
+   return v->visit_leave(this);
+}
+
+
+ir_visitor_status
+ir_return::accept(ir_hierarchical_visitor *v)
+{
+   ir_visitor_status s = v->visit_enter(this);
+   if (s != visit_continue)
+      return (s == visit_continue_with_parent) ? visit_continue : s;
+
+   ir_rvalue *val = this->get_value();
+   if (val) {
+      s = val->accept(v);
+      if (s != visit_continue)
+	 return (s == visit_continue_with_parent) ? visit_continue : s;
+   }
+
+   return v->visit_leave(this);
+}
+
+
+ir_visitor_status
+ir_if::accept(ir_hierarchical_visitor *v)
+{
+   ir_visitor_status s = v->visit_enter(this);
+   if (s != visit_continue)
+      return (s == visit_continue_with_parent) ? visit_continue : s;
+
+   s = this->condition->accept(v);
+   if (s != visit_continue)
+      return (s == visit_continue_with_parent) ? visit_continue : s;
+
+   if (s != visit_continue_with_parent) {
+      s = visit_list_elements(v, &this->then_instructions);
+      if (s == visit_stop)
+	 return s;
+   }
+
+   if (s != visit_continue_with_parent) {
+      s = visit_list_elements(v, &this->else_instructions);
+      if (s == visit_stop)
+	 return s;
+   }
+
+   return v->visit_leave(this);
+}