src/gdb ChangeLog ada-lang.c

[guitton at sourceware dot org]

CVSROOT:	/cvs/src
Module name:	src
Changes by:	guitton@sourceware.org	2012-11-29 16:26:14

Modified files:
	gdb            : ChangeLog ada-lang.c 

Log message:
	Handle other cases than EVAL_NORMAL in the default case
	
	In the evaluation of an expression in Ada mode, the default case
	unwraps the argument unconditionally. For an object of a variant
	record type, this unwrapping builds a fixed type from the
	specification of the variant type and the actual values of the
	object's discriminants.  It means that unwrapping needs the "proper"
	value for the object, not just a zero value with the proper type.
	
	When not in EVAL_NORMAL, we cannot assume that the evaluation returns
	such a proper value; it may well return a zero value of the
	appropriate type e.g in EVAL_AVOID_SIDE_EFFECTS. It is wrong to try to
	unwrap in that case.
	
	In particular, a problem shows up when using expression of the form
	{VARIANT_TYPE}OBJ. GDB first evaluates this expression in
	EVAL_AVOID_SIDE_EFFECTS to compute the type, the evaluation of OBJ
	in most cases returns a zero value of its type, and as UNOP_MEMVAL
	is mapped to the default case its evaluation ends up trying to
	read memory around address 0.
	
	gdb/ChangeLog:
	
	* ada-lang.c (ada_evaluate_subexp): Unwrap only in EVAL_NORMAL.

Patches:
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/ChangeLog.diff?cvsroot=src&r1=1.14867&r2=1.14868
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/ada-lang.c.diff?cvsroot=src&r1=1.381&r2=1.382