Re: [PATCH 3/3] Add -file-list-shared-libraries MI command

Pedro Alves
2016-11-23T13:06:27Z

Hi Marc-Andre,

Great that you're tackling this. Thanks much for digging into GDB. :-)
I like this. As for following GDB's code standards, it's almost perfect.

But I have questions on the MI output, though. See below.

On 09/12/2016 09:27 PM, Marc-Andre Laperle wrote:

> diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
> index d1a5e7c..c6b2133 100644
> --- a/gdb/doc/gdb.texinfo
> +++ b/gdb/doc/gdb.texinfo
> @@ -31401,26 +31401,35 @@ The @value{GDBN} equivalent is @samp{info sources}.
> (gdb)
> @end smallexample
>
> -@ignore
> @subheading The @code{-file-list-shared-libraries} Command
> @findex -file-list-shared-libraries
>
> @subsubheading Synopsis
>
> @smallexample
> - -file-list-shared-libraries
> + -file-list-shared-libraries [ @var{regexp} ]
> @end smallexample
>
> List the shared libraries in the program.
> +With a regular expression @var{regexp}, only those libraries whose
> +names match @var{regexp} are listed.
>
> @subsubheading @value{GDBN} Command
>
> The corresponding @value{GDBN} command is @samp{info shared}.
>
> @subsubheading Example
> -N.A.
> +@smallexample
> +(gdb)
> +-file-list-exec-source-files
> +^done,shared-libraries=[
> +@{from="0x72815989",to="0x728162c0",syms-read="1",name="/lib/libfoo.so"@},
> +@{from="0x76ee48c0",to="0x76ee9160",syms-read="1",name="/lib/libbar.so"@}]

I don't see where the documentation describes what the
attributes of each list element are. Sorry if I missed it.

I find it surprising that the attributes output don't match
attributes output by =library-loaded ? I'd think they should
match. That'd simplify the documentation too, as one place
would refer to the other for attributes list.

BTW, =library-loaded doesn't output from/to. ISTR that that
was discussed and left out, because from/to assume there's
a contiguous range to report, while that's not true on all
targets (i.e., assumes a single segment). So it seems to
me that that's a separate discussion/patch would better
be addressed in both places.

> +void
> +mi_cmd_file_list_shared_libraries (char *command, char **argv, int argc)
> +{
> + struct ui_out *uiout = current_uiout;
> + const char *pattern;
> + struct so_list *so = NULL;
> + struct gdbarch *gdbarch = target_gdbarch ();
> +
> + switch (argc)
> + {
> + case 0:
> + pattern = NULL;
> + break;
> + case 1:
> + pattern = argv[0];
> + break;
> + default:
> + error (_("Usage: -file-list-shared-libraries [REGEXP]"));
> + break;

error doesn't return. No need for the break.

> + }
> +
> + if (pattern != NULL)
> + {
> + char *re_err = re_comp (pattern);
> +
> + if (re_err != NULL)
> + error (_("Invalid regexp: %s"), re_err);
> + }
> +
> + update_solib_list (1);
> +
> + /* Print the table header. */
> + ui_out_begin (uiout, ui_out_type_list, "shared-libraries");
> +
> + ALL_SO_LIBS (so)
> + {
> + if (so->so_name[0] == '\0')
> + continue;
> + if (pattern != NULL && !re_exec (so->so_name))
> + continue;
> +
> + ui_out_begin (uiout, ui_out_type_tuple, NULL);
> +
> + if (so->addr_high != 0)
> + {
> + ui_out_field_core_addr (uiout, "from", gdbarch, so->addr_low);
> + ui_out_field_core_addr (uiout, "to", gdbarch, so->addr_high);
> + }
> + else
> + {
> + ui_out_field_skip (uiout, "from");
> + ui_out_field_skip (uiout, "to");
> + }
> +
> + ui_out_field_int (uiout, "syms-read", so->symbols_loaded ? 1 : 0);
> +
> + ui_out_field_string (uiout, "name", so->so_name);

So seems to me that the inner body of this loop would be better
calling a function that is shared with =library-loaded.

> +

> --- a/gdb/solist.h
> +++ b/gdb/solist.h
> @@ -23,6 +23,11 @@
> /* For domain_enum domain. */
> #include "symtab.h"
>
> +#define ALL_SO_LIBS(so) \
> + for (so = current_program_space->so_list; \
> + so; \

Write explicit 'so != NULL'.

> + so = so->next)
> +
> /* Forward declaration for target specific link map information. This
> struct is opaque to all but the target specific file. */
> struct lm_info;
> diff --git a/gdb/testsuite/gdb.mi/mi-solib.exp b/gdb/testsuite/gdb.mi/mi-solib.exp
> index 2227987..4c40ba4 100644
> --- a/gdb/testsuite/gdb.mi/mi-solib.exp
> +++ b/gdb/testsuite/gdb.mi/mi-solib.exp
> @@ -48,27 +48,47 @@ if { [gdb_compile_shlib ${srcfile_lib} ${binfile_lib} $lib_flags] != ""
>
> mi_delete_breakpoints
> mi_gdb_reinitialize_dir $srcdir/$subdir
> -mi_gdb_reinitialize_dir $srcdir/$subdir
> mi_gdb_load ${binfile}
>
> mi_load_shlibs $binfile_lib
>
> -mi_gdb_test "777-gdb-set stop-on-solib-events 1" "777\\^done" \
> - "set stop-on-solib-events"
> +proc test_stop_on_solib_events {} {

Looks like a good candidate for the the new proc_with_prefix.

> + mi_gdb_test "777-gdb-set stop-on-solib-events 1" "777\\^done" \
> + "set stop-on-solib-events"
>
> -# We use "run" rather than "-exec-run" here in order to test that CLI
> -# commands still cause the correct MI output to be generated.
> -mi_run_with_cli
> + # We use "run" rather than "-exec-run" here in order to test that CLI
> + # commands still cause the correct MI output to be generated.
> + mi_run_with_cli
>
> -# Also test that the CLI solib event note is output.
> -set test "CLI prints solib event"
> -gdb_expect {
> - -re "~\"Stopped due to shared library event \\(no libraries added or removed\\)\\\\n" {
> - pass "$test"
> - }
> - timeout {
> - fail "$test (timeout)"
> + # Also test that the CLI solib event note is output.
> + set test "CLI prints solib event"
> + gdb_expect {
> + -re "~\"Stopped due to shared library event \\(no libraries added or removed\\)\\\\n" {
> + pass "$test"
> + }
> + timeout {
> + fail "$test (timeout)"
> + }
> }
> +
> + mi_expect_stop solib-event .* .* .* .* .* "check for solib event"
> +
> + # Unset solib events to avoid interfering with other tests.
> + mi_gdb_test "778-gdb-set stop-on-solib-events 0" "778\\^done" \
> + "unset stop-on-solib-events"
> +}
> +
> +proc test_file_list_shared_libraries {} {
> + global libname
> + global binfile
> +
> + mi_continue_to main
> +
> + mi_gdb_test "222-file-list-shared-libraries" \
> + "222\\^done,shared-libraries=\\\[.*\{from=\".*\",to=\".*\",syms-read=\"1\",name=\".*${libname}.so\"\}.*]" \
> + "Getting a list of shared libraries."

Lowercase, no period at end, and use imperative:

"get list of shared libraries"

Thanks,
Pedro Alves