src/gdb ChangeLog mi/mi-cmd-stack.c testsuite/ ...

[brobecke at sourceware dot org]

CVSROOT:	/cvs/src
Module name:	src
Changes by:	brobecke@sourceware.org	2012-02-03 07:32:40

Modified files:
	gdb            : ChangeLog 
	gdb/mi         : mi-cmd-stack.c 
	gdb/testsuite  : ChangeLog 
Added files:
	gdb/testsuite/gdb.ada: mi_task_arg.exp 
	gdb/testsuite/gdb.ada/mi_task_arg: task_switch.adb 

Log message:
	GDB/MI: crash printing "_task" (Ada) argument
	
	In GDB/MI mode, trying to print the arguments of the frame corresponding
	to the body of a task ("-stack-list-arguments 1") causes the debugger to
	crash.
	
	This is because the compiler adds an implicit argument to that task body
	called "_task". mi/mi-cmd-stack.c:list_args_or_locals, which is
	responsible for printing the value of our arguments, finds that our
	"_task" symbol is an argument, and thus tries to fing the non-argument
	equivalent:
	
	if (SYMBOL_IS_ARGUMENT (sym))
	sym2 = lookup_symbol (SYMBOL_NATURAL_NAME (sym),
	block, VAR_DOMAIN,
	(int *) NULL);
	
	Unfortunately, it tries using the natural name, which doesn't always
	work for Ada parameters, in particular those who are internally-
	generated. In our case, The "_task" parameter's natural name is
	"<_task>", and that symbol does not exist.  So sym2 is NULL, thus
	causing the crash a little later on when trying to dereference it.
	We should be using the symbol linkage name in this case, the same
	way iterate_over_block_arg_vars already does.
	
	gdb/ChangeLog:
	
	* mi/mi-cmd-stack.c (list_args_or_locals): For argument symbols,
	use SYMBOL_LINKAGE_NAME to find the corresponding non-argument
	symbol.  Add assertion that sym2 is never NULL.
	
	gdb/testsuite/ChangeLog:
	
	* gdb.ada/mi_task_arg: New testcase.

Patches:
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/ChangeLog.diff?cvsroot=src&r1=1.13804&r2=1.13805
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/mi/mi-cmd-stack.c.diff?cvsroot=src&r1=1.61&r2=1.62
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/testsuite/ChangeLog.diff?cvsroot=src&r1=1.3059&r2=1.3060
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/testsuite/gdb.ada/mi_task_arg.exp.diff?cvsroot=src&r1=NONE&r2=1.1
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/testsuite/gdb.ada/mi_task_arg/task_switch.adb.diff?cvsroot=src&r1=NONE&r2=1.1