From 3c7934bfaae5dff410cddba3ac6696a8911c0c68 Mon Sep 17 00:00:00 2001
From: Kenneth Graunke <kenneth@whitecape.org>
Date: Wed, 26 May 2010 17:52:44 -0700
Subject: [PATCH] ir_reader: Refactor reading of dereferences for later reuse.

---
 ir_reader.cpp | 34 ++++++++++++++++++++++++++--------
 1 file changed, 26 insertions(+), 8 deletions(-)

diff --git a/ir_reader.cpp b/ir_reader.cpp
index f4b9967..019631f 100644
--- a/ir_reader.cpp
+++ b/ir_reader.cpp
@@ -53,6 +53,9 @@ static ir_expression *read_expression(_mesa_glsl_parse_state *, s_list *);
 static ir_call *read_call(_mesa_glsl_parse_state *, s_list *);
 static ir_swizzle *read_swizzle(_mesa_glsl_parse_state *, s_list *);
 static ir_constant *read_constant(_mesa_glsl_parse_state *, s_list *);
+
+static ir_dereference *read_dereference(_mesa_glsl_parse_state *,
+				        s_expression *);
 static ir_dereference *read_var_ref(_mesa_glsl_parse_state *, s_list *);
 static ir_dereference *read_array_ref(_mesa_glsl_parse_state *, s_list *);
 static ir_dereference *read_record_ref(_mesa_glsl_parse_state *, s_list *);
@@ -528,8 +531,10 @@ read_rvalue(_mesa_glsl_parse_state *st, s_expression *expr)
       return NULL;
    }
 
-   ir_rvalue *rvalue = NULL;
-   if (strcmp(tag->value(), "swiz") == 0) {
+   ir_rvalue *rvalue = read_dereference(st, list);
+   if (rvalue != NULL || st->error)
+      return rvalue;
+   else if (strcmp(tag->value(), "swiz") == 0) {
       rvalue = read_swizzle(st, list);
    } else if (strcmp(tag->value(), "assign") == 0) {
       rvalue = read_assignment(st, list);
@@ -539,12 +544,6 @@ read_rvalue(_mesa_glsl_parse_state *st, s_expression *expr)
       rvalue = read_call(st, list);
    } else if (strcmp(tag->value(), "constant") == 0) {
       rvalue = read_constant(st, list);
-   } else if (strcmp(tag->value(), "var_ref") == 0) {
-      rvalue = read_var_ref(st, list);
-   } else if (strcmp(tag->value(), "array_ref") == 0) {
-      rvalue = read_array_ref(st, list);
-   } else if (strcmp(tag->value(), "record_ref") == 0) {
-      rvalue = read_record_ref(st, list);
    } else {
       ir_read_error(st, expr, "unrecognized rvalue tag: %s", tag->value());
    }
@@ -818,6 +817,25 @@ read_constant(_mesa_glsl_parse_state *st, s_list *list)
 }
 
 static ir_dereference *
+read_dereference(_mesa_glsl_parse_state *st, s_expression *expr)
+{
+   s_list *list = SX_AS_LIST(expr);
+   if (list == NULL || list->subexpressions.is_empty())
+      return NULL;
+
+   s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.head);
+   assert(tag != NULL);
+
+   if (strcmp(tag->value(), "var_ref") == 0)
+      return read_var_ref(st, list);
+   if (strcmp(tag->value(), "array_ref") == 0)
+      return read_array_ref(st, list);
+   if (strcmp(tag->value(), "record_ref") == 0)
+      return read_record_ref(st, list);
+   return NULL;
+}
+
+static ir_dereference *
 read_var_ref(_mesa_glsl_parse_state *st, s_list *list)
 {
    if (list->length() != 2) {
-- 
2.7.4