From f7e44f6574a59496a4635c91080d635d095f81c8 Mon Sep 17 00:00:00 2001 From: Joel Brobecker Date: Fri, 3 Feb 2012 07:32:40 +0000 Subject: 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. --- gdb/mi/mi-cmd-stack.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'gdb/mi') diff --git a/gdb/mi/mi-cmd-stack.c b/gdb/mi/mi-cmd-stack.c index c0c17bc..4ad9f7c 100644 --- a/gdb/mi/mi-cmd-stack.c +++ b/gdb/mi/mi-cmd-stack.c @@ -389,11 +389,12 @@ list_args_or_locals (enum what_to_list what, enum print_values values, struct frame_arg arg, entryarg; if (SYMBOL_IS_ARGUMENT (sym)) - sym2 = lookup_symbol (SYMBOL_NATURAL_NAME (sym), + sym2 = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), block, VAR_DOMAIN, (int *) NULL); else sym2 = sym; + gdb_assert (sym2 != NULL); memset (&arg, 0, sizeof (arg)); arg.sym = sym2; -- cgit v1.1