[v2] Don't put JIT_READER_DIR into help text

  The 80-column-help-string self-test can fail if gdb's install
directory is too long, because the help for "jit-reader-load" includes
JIT_READER_DIR.

This help text is actually somewhat misleading, though.
JIT_READER_DIR is not actually used directly -- instead the relocated
variant is used.

This patch adds a new "show jit-reader-directory" command and changes
the help text to refer to this instead.  I considered adding a "set"
command as well, but since absolute paths are acceptable here, and
since this is a very niche command anyway, I figured there was no need
to bother.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32357
Reviewed-By: Kévin Le Gouguec <legouguec@adacore.com>
---
 gdb/NEWS                              |  4 ++++
 gdb/doc/gdb.texinfo                   |  4 ++++
 gdb/jit.c                             | 21 +++++++++++++++++++--
 gdb/testsuite/gdb.base/jit-reader.exp |  4 ++++
 4 files changed, 31 insertions(+), 2 deletions(-)
  

> From: Tom Tromey <tromey@adacore.com>
> Cc: Tom Tromey <tromey@adacore.com>,
>  Kévin Le Gouguec <legouguec@adacore.com>
> Date: Tue, 19 Nov 2024 12:35:27 -0700
> 
> The 80-column-help-string self-test can fail if gdb's install
> directory is too long, because the help for "jit-reader-load" includes
> JIT_READER_DIR.
> 
> This help text is actually somewhat misleading, though.
> JIT_READER_DIR is not actually used directly -- instead the relocated
> variant is used.
> 
> This patch adds a new "show jit-reader-directory" command and changes
> the help text to refer to this instead.  I considered adding a "set"
> command as well, but since absolute paths are acceptable here, and
> since this is a very niche command anyway, I figured there was no need
> to bother.
> 
> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32357
> Reviewed-By: Kévin Le Gouguec <legouguec@adacore.com>
> ---
>  gdb/NEWS                              |  4 ++++
>  gdb/doc/gdb.texinfo                   |  4 ++++
>  gdb/jit.c                             | 21 +++++++++++++++++++--
>  gdb/testsuite/gdb.base/jit-reader.exp |  4 ++++
>  4 files changed, 31 insertions(+), 2 deletions(-)

Thanks, the documentation parts are okay.

Reviewed-By: Eli Zaretskii <eliz@gnu.org>
  

Tom Tromey <tromey@adacore.com> writes:

> The 80-column-help-string self-test can fail if gdb's install
> directory is too long, because the help for "jit-reader-load" includes
> JIT_READER_DIR.
>
> This help text is actually somewhat misleading, though.
> JIT_READER_DIR is not actually used directly -- instead the relocated
> variant is used.
>
> This patch adds a new "show jit-reader-directory" command and changes
> the help text to refer to this instead.  I considered adding a "set"
> command as well, but since absolute paths are acceptable here, and
> since this is a very niche command anyway, I figured there was no need
> to bother.
>
> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32357
> Reviewed-By: Kévin Le Gouguec <legouguec@adacore.com>

LGTM.

Approved-By: Andrew Burgess <aburgess@redhat.com>

Thanks,
Andrew

> ---
>  gdb/NEWS                              |  4 ++++
>  gdb/doc/gdb.texinfo                   |  4 ++++
>  gdb/jit.c                             | 21 +++++++++++++++++++--
>  gdb/testsuite/gdb.base/jit-reader.exp |  4 ++++
>  4 files changed, 31 insertions(+), 2 deletions(-)
>
> diff --git a/gdb/NEWS b/gdb/NEWS
> index 046daad0eae..f3c5d720b15 100644
> --- a/gdb/NEWS
> +++ b/gdb/NEWS
> @@ -94,6 +94,10 @@
>  
>  * New commands
>  
> +show jit-reader-directory
> +  Show the name of the directory that "jit-reader-load" uses for
> +  relative file names.
> +
>  set style line-number foreground COLOR
>  set style line-number background COLOR
>  set style line-number intensity VALUE
> diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
> index 99720f1206e..b91b5d693ed 100644
> --- a/gdb/doc/gdb.texinfo
> +++ b/gdb/doc/gdb.texinfo
> @@ -40047,6 +40047,10 @@ reporting an error.  A new JIT reader can be loaded by first unloading
>  the current one using @code{jit-reader-unload} and then invoking
>  @code{jit-reader-load}.
>  
> +@item show jit-reader-directory
> +This command will show the directory that is used by
> +@code{jit-reader-load} when a relative file name is specified.
> +
>  @item jit-reader-unload
>  Unload the currently loaded JIT reader.
>  
> diff --git a/gdb/jit.c b/gdb/jit.c
> index 48be1c880c9..77d41bf86ba 100644
> --- a/gdb/jit.c
> +++ b/gdb/jit.c
> @@ -28,6 +28,7 @@
>  #include "filenames.h"
>  #include "frame-unwind.h"
>  #include "cli/cli-cmds.h"
> +#include "cli/cli-style.h"
>  #include "gdbcore.h"
>  #include "inferior.h"
>  #include "observable.h"
> @@ -1298,6 +1299,16 @@ jit_event_handler (gdbarch *gdbarch, objfile *jiter)
>      }
>  }
>  
> +/* Implementation of "show jit-reader-directory".  */
> +
> +static void
> +show_jit_reader_directory (const char *args, int from_tty)
> +{
> +  gdb_printf (_("JIT reader directory is %ps.\n"),
> +	      styled_string (file_name_style.style (),
> +			     jit_reader_dir.c_str ()));
> +}
> +
>  void _initialize_jit ();
>  void
>  _initialize_jit ()
> @@ -1329,8 +1340,8 @@ _initialize_jit ()
>  Load FILE as debug info reader and unwinder for JIT compiled code.\n\
>  Usage: jit-reader-load FILE\n\
>  Try to load file FILE as a debug info reader (and unwinder) for\n\
> -JIT compiled code.  The file is loaded from " JIT_READER_DIR ",\n\
> -relocated relative to the GDB executable if required."));
> +JIT compiled code.  If FILE is not an absolute file name, it is found\n\
> +relative to a built-in directory.  See \"show jit-reader-directory\"."));
>        set_cmd_completer (c, deprecated_filename_completer);
>  
>        c = add_com ("jit-reader-unload", no_class,
> @@ -1339,5 +1350,11 @@ Unload the currently loaded JIT debug info reader.\n\
>  Usage: jit-reader-unload\n\n\
>  Do \"help jit-reader-load\" for info on loading debug info readers."));
>        set_cmd_completer (c, noop_completer);
> +
> +      add_cmd ("jit-reader-directory", class_obscure,
> +	       show_jit_reader_directory,
> +	       _("Show the JIT reader directory.\n\
> +This is the directory used by \"jit-reader-load\" when given\n\
> +a relative file name."), &showlist);
>      }
>  }
> diff --git a/gdb/testsuite/gdb.base/jit-reader.exp b/gdb/testsuite/gdb.base/jit-reader.exp
> index 62f6af29ac1..2a96207346c 100644
> --- a/gdb/testsuite/gdb.base/jit-reader.exp
> +++ b/gdb/testsuite/gdb.base/jit-reader.exp
> @@ -109,6 +109,10 @@ proc jit_reader_test {} {
>  	gdb_test_no_output "set debug jit 1"
>      }
>  
> +    # Just test that this is installed and prints something.
> +    gdb_test "show jit-reader-directory" \
> +	"JIT reader directory is .*\\."
> +
>      gdb_test_no_output "jit-reader-load ${jit_reader_bin}" "jit-reader-load"
>      gdb_run_cmd
>      gdb_test "" "Program received signal SIGTRAP, .*" "expect SIGTRAP"
> -- 
> 2.47.0