Re: [PATCH] Add proper handling for non-local references in nested functions

[Doug Evans <xdje42@gmail.com>]

Joel Brobecker <brobecker@adacore.com> writes:
> Hi Pierre-Marie,
>
>> >From f8cb12e93bc4b317bf03dd31fc158cc05fc60367 Mon Sep 17 00:00:00 2001
>> From: Pierre-Marie de Rodat <derodat@adacore.com>
>> Date: Thu, 5 Feb 2015 17:00:06 +0100
>> Subject: [PATCH] DWARF: handle non-local references in nested functions
>> 
>> GDB's current behavior when dealing with non-local references in the
>> context of nested fuctions is approximative:
>> 
>>   - code using valops.c:value_of_variable read the first available stack
>>     frame that holds the corresponding variable (whereas there can be
>>     multiple candidates for this);
>> 
>>   - code directly relying on read_var_value will instead read non-local
>>     variables in frames where they are not even defined.
>> 
>> This change adds the necessary context to symbol reads (to get the block
>> they belong to) and to blocks (the static link property, if any) so that
>> GDB can make the proper decisions when dealing with non-local varibale
>> references.
>> 
>> gdb/ChangeLog:
>> 
>> 	* ada-lang.c (ada_read_var_value): Add a var_block argument
>> 	and pass it to default_read_var_value.
>> 	* block.c (block_static_link): New accessor.
>> 	* block.h (block_static_link): Declare it.
>> 	* buildsym.c (finish_block_internal): Add a static_link
>>       [...]
>
> This patch is causing a crash on some platforms, as explained by
> the revision log of the attached patch.
>
> gdb/ChangeLog:
>
>         * dwarf2loc.c (locexpr_get_frame_base): Renames
>         block_op_get_frame_base.
>         (dwarf2_block_frame_base_locexpr_funcs): Replace reference to
>         block_op_get_frame_base by reference to locexpr_get_frame_base.
>         (loclist_get_frame_base): New function, near identical copy of
>         locexpr_get_frame_base.
>         (dwarf2_block_frame_base_loclist_funcs): Replace reference to
>         block_op_get_frame_base by reference to loclist_get_frame_base.

LGTM.