Mesa (master): glsl: Make ir_dereference_array constructor assert the variable exists.

[Kenneth Graunke]

Module: Mesa
Branch: master
Commit: 25b0d45d038774406f2bb7173abc33a3cb261db2
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=25b0d45d038774406f2bb7173abc33a3cb261db2

Author: Kenneth Graunke <kenneth at whitecape.org>
Date:   Tue Mar 13 12:39:32 2012 -0700

glsl: Make ir_dereference_array constructor assert the variable exists.

Providing a NULL pointer to the ir_dereference_array() constructor seems
like a bad idea.  Currently, if provided NULL, it returns a partially
constructed value of error type.  However, none of the callers are
prepared to handle that scenario.

Code inspection shows that all callers do one of the following:
- Already NULL-check the argument prior to creating the dereference
- Already deference the argument (and thus would crash if it were NULL)
- Newly allocate the argument.

Thus, it should be safe to simply assert the value passed is not NULL.
This should also catch issues right away, rather than dying later.

Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
Reviewed-by: Eric Anholt <eric at anholt.net>

---

 src/glsl/ir.cpp |   19 +++++++++----------
 1 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/src/glsl/ir.cpp b/src/glsl/ir.cpp
index a5eca5a..3fc4a98 100644
--- a/src/glsl/ir.cpp
+++ b/src/glsl/ir.cpp
@@ -1055,19 +1055,18 @@ ir_dereference_array::ir_dereference_array(ir_variable *var,
 void
 ir_dereference_array::set_array(ir_rvalue *value)
 {
+   assert(value != NULL);
+
    this->array = value;
-   this->type = glsl_type::error_type;
 
-   if (this->array != NULL) {
-      const glsl_type *const vt = this->array->type;
+   const glsl_type *const vt = this->array->type;
 
-      if (vt->is_array()) {
-	 type = vt->element_type();
-      } else if (vt->is_matrix()) {
-	 type = vt->column_type();
-      } else if (vt->is_vector()) {
-	 type = vt->get_base_type();
-      }
+   if (vt->is_array()) {
+      type = vt->element_type();
+   } else if (vt->is_matrix()) {
+      type = vt->column_type();
+   } else if (vt->is_vector()) {
+      type = vt->get_base_type();
    }
 }