kc3-lang/gnulib/m4

Diff

  • Show log

    Commit

  • Hash : 3f0950f6
    Author : Bruno Haible
    Date : 2023-04-27T01:42:25 

    fdopendir: Fix fd leak and test failure on native Windows.

* lib/dirent-private.h: On mingw, define 'struct gl_directory' as a
wrapper around the original DIR. On MSVC, add an 'fd_to_close' field to
'struct gl_directory'.
* lib/dirent.in.h (DIR): Define when DIR_HAS_FD_MEMBER is 0, i.e. on
both mingw and MSVC.
(GNULIB_defined_DIR): New macro.
(opendir): Avoid incompatible redeclaration.
(readdir): Consider REPLACE_READDIR.
(rewinddir): Consider REPLACE_REWINDDIR.
* m4/dirent_h.m4 (gl_DIRENT_DIR): New macro.
(gl_DIRENT_H): Invoke it.
(gl_DIRENT_H_DEFAULTS): Initialize REPLACE_READDIR, REPLACE_REWINDDIR.
* modules/dirent (Makefile.am): Substitute DIR_HAS_FD_MEMBER,
REPLACE_READDIR, REPLACE_REWINDDIR.
--
* lib/dirfd.c (dirfd): If GNULIB_defined_DIR, just use the
'fd_to_close' field.
* m4/dirfd.m4 (gl_FUNC_DIRFD): Set HAVE_DIRFD. Don't set REPLACE_DIRFD
to 1 if HAVE_DIRFD is 0. If DIR_HAS_FD_MEMBER is 0, ensure dirfd.c gets
compiled.
* modules/dirfd (Files): Add lib/dirent-private.h.
(Depends-on, configure.ac): Simplify conditions.
--
* lib/closedir.c: Include <stdlib.h> always, for free().
(closedir): If GNULIB_defined_DIR, arrange to call close(dirfd(dirp)) at
the end. On mingw, call free() of dirp. Prefer testing HAVE_DIRENT_H,
for consistency with dirent.h.
* m4/closedir.m4 (gl_FUNC_CLOSEDIR): Don't set REPLACE_CLOSEDIR to 1 if
HAVE_CLOSEDIR is 0. If DIR_HAS_FD_MEMBER is 0, ensure closedir.c gets
compiled.
--
* lib/opendir.c: Include <stdlib.h> always. Include <string.h>.
(opendir): On mingw, allocate the 'struct gl_directory' through malloc.
If GNULIB_defined_DIR, set the 'fd_to_close' field to -1. Prefer
testing HAVE_DIRENT_H, for consistency with dirent.h.
* m4/opendir.m4 (gl_FUNC_OPENDIR): Don't set REPLACE_OPENDIR to 1 if
HAVE_OPENDIR is 0. If DIR_HAS_FD_MEMBER is 0, ensure opendir.c gets
compiled.
--
* lib/fdopendir.c (fdopendir): If GNULIB_defined_DIR, use a simple
implementation based on opendir and the fchdir module. If __KLIBC__,
don't define unused auxiliary functions.
* modules/fdopendir (Files): Add lib/dirent-private.h.
--
* lib/readdir.c (readdir): On mingw, redirect to the original readdir
function. Prefer testing HAVE_DIRENT_H, for consistency with dirent.h.
* m4/readdir.m4 (gl_FUNC_READDIR): If DIR_HAS_FD_MEMBER is 0, ensure
readdir.c gets compiled.
* modules/readdir (configure.ac): Consider REPLACE_READDIR.
--
* lib/rewinddir.c (rewinddir): On mingw, redirect to the original
rewinddir function. Prefer testing HAVE_DIRENT_H, for consistency with
dirent.h.
* m4/rewinddir.m4 (gl_FUNC_REWINDDIR): If DIR_HAS_FD_MEMBER is 0, ensure
rewinddir.c gets compiled.
* modules/rewinddir (configure.ac): Consider REPLACE_REWINDDIR.
--
* lib/fchdir.c (dir_info_t): Remove a FIXME.

  • README

  • Many of the files in this directory are shared between the coreutils,
diffutils, tar and gettext packages -- and others, so if you
change them, try to ensure that you don't break those packages.
That's hard without a systematic approach, but here is a set of conventions
that makes it easy.

- The lib/ sources are split into modules.  Usually the module of a
  lib/foo.h and lib/foo.c is called "foo" - not unexpected, hey! -, but
  in more ambiguous cases you can look up the module a file belongs to
  by doing "grep lib/foo.c modules/*".

- For every module there is an autoconf macro file, usually called
  m4/foo.m4 according to the module name.  When you modify lib/foo.h or
  lib/foo.c, remember to modify m4/foo.m4 as well!
  What if you don't find m4/foo.m4? This probably means that the module
  doesn't need autoconf support up to now (again, take a look in modules/*).
  So you might need to create one.

- A module which defines a replacement function (i.e. a function which is
  compiled only on systems which lack it or where it exists but doesn't
  work satisfactorily) has a .m4 file with typically the following structure:

  AC_DEFUN([gl_FUNC_FOO],
  [
    AC_REPLACE_FUNCS(foo)
    if test $ac_cv_func_foo = no; then
      gl_PREREQ_FOO
    fi
  ])

  # Prerequisites of lib/foo.c.
  AC_DEFUN([gl_PREREQ_FOO], [
    dnl Many AC_CHECK_* invocations.
  ])

- A module which is compiled on all platforms can define multiple functions
  and be spread across multiple source files (although each time you do
  this you should consider splitting the module, if the source files could
  be independent). The .m4 file has typically the following structure:

  AC_DEFUN([gl_FOO],
  [
    dnl Prerequisites of lib/foo.c.
    dnl Many AC_CHECK_* invocations.

    dnl Prerequisites of lib/foobar.c.
    dnl Many AC_CHECK_* invocations.
  ])

- When a module FOO depends on a module BAR, you do *not* generally need
  to write

  AC_DEFUN([gl_FOO],
  [
    AC_REQUIRE([gl_BAR])
    ...
  ])

  because the maintainers might want to use locally modified / renamed copies
  of the module BAR.

- If the autoconf tests for the modules FOO and BAR have some checks in
  common, still list them separately. Autoconf has two mechanisms for
  avoiding that a configure file runs the same test twice: AC_REQUIRE
  and AC_CACHE_CHECK. Trying to omit the checks leads to maintenance
  problems: If FOO depends on BAR, and you omit a check from FOO's .m4 file,
  later on, when someone modifies bar.c and removes the check from bar.m4,
  he will not remember that foo.c needs the check as well.

- Now, how can you find the prerequisites of lib/foo.c? Try this:
    "grep '#.*if' lib/foo.c | grep -v endif"
  and for each HAVE_* macro search in the autoconf documentation what could
  be the autoconf macro that provides it. This is only an approximation; in
  general you should look at all preprocessor directives in lib/foo.c.

- In AC_RUN_IFELSE invocations, try to put as much information about failed
  tests as possible in the exit code. The exit code is 0 for success and any
  value between 1 and 127 for failure. The exit code is printed in config.log;
  therefore when an AC_RUN_IFELSE invocation failed, it is possible to analyze
  the failure immediately if sufficient information is contained in the exit
  code.

  For a program that performs a single test, the typical idiom is:

      if (do_test1 ())
        return 1;
      return 0;

  For a test that performs a test with some preparation, the typical idiom is
  to return an enumerated value:

      if (prep1 ())
        return 1;
      else if (prep2 ())
        return 2;
      else if (prep3 ())
        return 3;
      else if (do_test1 ())
        return 4;
      return 0;

  For multiple independent tests in a single program, you can return a bit
  mask with up to 7 bits:

      int result = 0;
      if (do_test1 ())
        result |= 1;
      if (do_test2 ())
        result |= 2;
      if (do_test3 ())
        result |= 4;
      return result;

  For more than 7 independent tests, you have to map some possible test
  failures to same bit.

- After ANY modifications of an m4 file, you should increment its serial
  number (in the first line). Also, if this first line features a particular
  release, _remove_ this release stamp. Example: Change

    # setenv.m4 serial 2 (gettext-0.11.1)

  into

    # setenv.m4 serial 3

kmx.io     mail     discord kmxgit v0.4.0