[PATCH 2/2] gdb: Forward VALUE_LVAL when avoiding side effects for STRUCTOP_STRUCT

[Andrew Burgess <andrew.burgess@embecosm.com>]

When evaluating an expression with EVAL_AVOID_SIDE_EFFECTS if the value
we return is forced to be of type not_lval then GDB will be unable to
take the address of the returned value.

Instead, we should properly initialise the LVAL of the returned value.

This commit builds on two previous commits 2520f728b710 and
c244f977c7b8, which in turn build on ac1ca910d74d.  This commit is
currently untested due to my lack of access to an OpenCL compiler,
however, if follows the same pattern as the previous two commits and so
I believe that it is correct.

gdb/ChangeLog:

	* opencl-lang.c (evaluate_subexp_opencl): If
	EVAL_AVOID_SIDE_EFFECTS mode, forward the VALUE_LVAL attribute to
	the returned value in the STRUCTOP_STRUCT case.
---
 gdb/ChangeLog     | 6 ++++++
 gdb/opencl-lang.c | 2 +-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 7644c08..b9005a3 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,11 @@
 2016-05-24  Andrew Burgess  <andrew.burgess@embecosm.com>
 
+	* opencl-lang.c (evaluate_subexp_opencl): If
+	EVAL_AVOID_SIDE_EFFECTS mode, forward the VALUE_LVAL attribute to
+	the returned value in the STRUCTOP_STRUCT case.
+
+2016-05-24  Andrew Burgess  <andrew.burgess@embecosm.com>
+
 	* eval.c (evaluate_subexp_standard): If EVAL_AVOID_SIDE_EFFECTS
 	mode, forward the VALUE_LVAL attribute to the returned value in
 	the STRUCTOP_PTR case.
diff --git a/gdb/opencl-lang.c b/gdb/opencl-lang.c
index 7799735..767d3bc 100644
--- a/gdb/opencl-lang.c
+++ b/gdb/opencl-lang.c
@@ -984,7 +984,7 @@ Cannot perform conditional operation on vectors with different sizes"));
 						"structure");
 
 	    if (noside == EVAL_AVOID_SIDE_EFFECTS)
-	      v = value_zero (value_type (v), not_lval);
+	      v = value_zero (value_type (v), VALUE_LVAL (v));
 	    return v;
 	  }
       }
-- 
2.5.1