Re: [PATCH] Try to initialize data-directory by first searching for "data-directory" in the same directory as the gdb binary

Jan Kratochvil
2012-09-19T13:01:14Z

On Tue, 18 Sep 2012 22:32:40 +0200, Khoo Yit Phang wrote:
> As discussed previously, here a patch that tries to initialize
> data-directory by first searching for "data-directory" in the same directory
> as the gdb binary.

I do not see how is it related to the 'isdir' addition, IMO 'isdir' is an
unrelated patch which should be posted separately.

> Additionally, I've also reverted my previous change to cc-with-tweaks.sh
> that added the -data-directory flag, since it is no longer necessary.

It can be kept there, it does not harm anything and it then does not depend on
a bit magic relocate_gdb_directory.

Thanks,
Jan

> gdb/ChangeLog
>
> 2012-09-18 Khoo Yit Phang <khooyp@cs.umd.edu>
>
> Try to initialize data-directory by first searching for
> "data-directory" in the same directory as the gdb binary.
> * contrib/cc-with-tweaks.sh (GDB): Revert -data-directory
> additions that is now unnecessary.
> * main.c (relocate_path): Add an isdir argument, and check that
> the relocated file/directory exists.
> (relocate_gdb_directory): Remove the directory check that is
> subsumed by relocate_path.
> (get_init_files): Remove the file check that is subsumed by
> relocate_path.
> (relocate_gdb_data_directory): New function similar to
> relocate_gdb_directory, but specifically for data-directory.
> (captured_main): Call relocate_gdb_data_directory to initialize
> gdb_datadir.
>
> diff --git a/gdb/contrib/cc-with-tweaks.sh b/gdb/contrib/cc-with-tweaks.sh
> --- a/gdb/contrib/cc-with-tweaks.sh
> +++ b/gdb/contrib/cc-with-tweaks.sh
> @@ -19,8 +19,7 @@
> # This program requires gdb and objcopy in addition to gcc.
> # The default values are gdb from the build tree and objcopy from $PATH.
> # They may be overridden by setting environment variables GDB and OBJCOPY
> -# respectively. Note that GDB should contain the gdb binary as well as the
> -# -data-directory flag, e.g., "foo/gdb -data-directory foo/data-directory".
> +# respectively.
> # We assume the current directory is either $obj/gdb or $obj/gdb/testsuite.
> #
> # Example usage:
> @@ -47,13 +46,13 @@
> then
> if [ -f ./gdb ]
> then
> - GDB="./gdb -data-directory data-directory"
> + GDB="./gdb"
> elif [ -f ../gdb ]
> then
> - GDB="../gdb -data-directory ../data-directory"
> + GDB="../gdb"
> elif [ -f ../../gdb ]
> then
> - GDB="../../gdb -data-directory ../../data-directory"
> + GDB="../../gdb"
> else
> echo "$myname: unable to find usable gdb" >&2
> exit 1
> diff --git a/gdb/main.c b/gdb/main.c
> --- a/gdb/main.c
> +++ b/gdb/main.c
> @@ -91,17 +91,34 @@
>
> static void print_gdb_help (struct ui_file *);
>
> -/* Relocate a file or directory. PROGNAME is the name by which gdb
> - was invoked (i.e., argv[0]). INITIAL is the default value for the
> - file or directory. FLAG is true if the value is relocatable, false
> - otherwise. Returns a newly allocated string; this may return NULL
> - under the same conditions as make_relative_prefix. */
> +/* Relocate a file or directory, checking if it exists. PROGNAME is the
> + name by which gdb was invoked (i.e., argv[0]). INITIAL is the default
> + value for the file or directory. ISDIR is true if INITIAL is a
> + directory. FLAG is true if the value is relocatable, false otherwise.
> + Returns a newly allocated string; this may return NULL under the same
> + conditions as make_relative_prefix, or if the relocated path does not
> + exist. */

GDB comments are formatted to textwidth=72 which may explain this excessive
reformatting. Try to keep textwidth=72 instead of changes back and forth.

>
> static char *
> -relocate_path (const char *progname, const char *initial, int flag)
> +relocate_path (const char *progname, const char *initial, int isdir,
> + int flag)
> {
> if (flag)
> - return make_relative_prefix (progname, BINDIR, initial);
> + {
> + char *path;
> + path = make_relative_prefix (progname, BINDIR, initial);
> + if (path)
> + {
> + struct stat s;
> +
> + if (stat (path, &s) != 0 || (isdir && !S_ISDIR (s.st_mode)))
> + {
> + xfree (path);
> + path = NULL;
> + }
> + }
> + return path;
> + }
> return xstrdup (initial);
> }
>
> @@ -116,19 +133,52 @@
> {
> char *dir;
>
> - dir = relocate_path (gdb_program_name, initial, flag);
> - if (dir)
> + dir = relocate_path (gdb_program_name, initial, 1, flag);
> + if (!dir)
> + dir = xstrdup (initial);
> +
> + /* Canonicalize the directory. */
> + if (*dir)
> {
> - struct stat s;
> + char *canon_sysroot = lrealpath (dir);
>
> - if (stat (dir, &s) != 0 || !S_ISDIR (s.st_mode))
> + if (canon_sysroot)
> {
> xfree (dir);
> - dir = NULL;
> + dir = canon_sysroot;
> }
> }
> +
> + return dir;
> +}
> +
> +/* Like relocate_gdb_path, but specifically for data-directory. */
> +
> +static char *
> +relocate_gdb_data_directory (void)
> +{
> + char *dir;
> +
> + /* First try to find "data-directory" in the same directory as gdb.
> +
> + Use relocate_path only to resolve the parent directory of
> + gdb_program_name (i.e., based on PATH if necessary); relocate_path
> + (gdb_program_name, BINDIR "/data-directory") cannot be used to resolve
> + data-directory as it returns a path relative to the _grandparent
> + directory_ of gdb_program_name (munging the parent directory). */
> +
> + dir = relocate_path (gdb_program_name, BINDIR, 1, 1);
> + if (dir)
> + dir = reconcat (dir, dir, SLASH_STRING, "data-directory", NULL);
> +
> + /* Then try to find GDB_DATADIR relocated relative to gdb. */
> if (!dir)

It can be more clear by replacing this 'if (!dir)' by 'else'.

> - dir = xstrdup (initial);
> + dir = relocate_path (gdb_program_name, GDB_DATADIR, 1,
> + GDB_DATADIR_RELOCATABLE);

Why isn't here the original statement?
dir = relocate_gdb_directory (GDB_DATADIR, GDB_DATADIR_RELOCATABLE);

> +
> + /* Otherwise use GDB_DATADIR as is. */
> + if (!dir)
> + dir = xstrdup (GDB_DATADIR);

This can be moved to the 'else' block suggested above to simplify it.

>
> /* Canonicalize the directory. */
> if (*dir)
> @@ -162,15 +212,15 @@
>
> if (!initialized)
> {
> - struct stat homebuf, cwdbuf, s;
> + struct stat homebuf, cwdbuf;
> char *homedir, *relocated_sysgdbinit;
>
> if (SYSTEM_GDBINIT[0])
> {
> relocated_sysgdbinit = relocate_path (gdb_program_name,
> - SYSTEM_GDBINIT,
> + SYSTEM_GDBINIT, 0,
> SYSTEM_GDBINIT_RELOCATABLE);
> - if (relocated_sysgdbinit && stat (relocated_sysgdbinit, &s) == 0)
> + if (relocated_sysgdbinit)
> sysgdbinit = relocated_sysgdbinit;
> else
> xfree (relocated_sysgdbinit);
> @@ -363,8 +413,7 @@
> debug_file_directory = relocate_gdb_directory (DEBUGDIR,
> DEBUGDIR_RELOCATABLE);
>
> - gdb_datadir = relocate_gdb_directory (GDB_DATADIR,
> - GDB_DATADIR_RELOCATABLE);
> + gdb_datadir = relocate_gdb_data_directory ();
>
> #ifdef WITH_PYTHON_PATH
> {