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

[Pedro Alves <palves at redhat dot com>]

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