Re: [PATCH v4] ftw initial port

[Jeff Johnston <jjohnstn@redhat.com>]

Hi Eshan,

You need to check for #ifndef _weak_alias as opposed to #ifdef
_weakalias(name, aliasname).  You should not add parameters in the #ifndef
statement.

You will still need to address Corinna's comments.

-- Jeff J.

On Wed, Nov 4, 2020 at 1:58 PM Eshan Dhawan via Newlib <
newlib@sourceware.org> wrote:

> From: Eshan dhawan <eshandhawan51@gmail.com>
>
> Signed-off-by: Eshan Dhawan <eshandhawan51@gmail.com>
> ---
>  newlib/libc/include/ftw.h     |  69 +++++++++++++++
>  newlib/libc/posix/Makefile.am |   2 +-
>  newlib/libc/posix/ftw.c       |  34 ++++++++
>  newlib/libc/posix/nftw.c      | 156 ++++++++++++++++++++++++++++++++++
>  4 files changed, 260 insertions(+), 1 deletion(-)
>  create mode 100644 newlib/libc/include/ftw.h
>  create mode 100644 newlib/libc/posix/ftw.c
>  create mode 100644 newlib/libc/posix/nftw.c
>
> diff --git a/newlib/libc/include/ftw.h b/newlib/libc/include/ftw.h
> new file mode 100644
> index 000000000..e38b6540f
> --- /dev/null
> +++ b/newlib/libc/include/ftw.h
> @@ -0,0 +1,69 @@
> +/*
> +* Copyright © 2005-2020 Rich Felker, et al.
> +*
> +* Permission is hereby granted, free of charge, to any person obtaining
> +* a copy of this software and associated documentation files (the
> +* "Software"), to deal in the Software without restriction, including
> +* without limitation the rights to use, copy, modify, merge, publish,
> +* distribute, sublicense, and/or sell copies of the Software, and to
> +* permit persons to whom the Software is furnished to do so, subject to
> +* the following conditions:
> +*
> +* The above copyright notice and this permission notice shall be
> +* included in all copies or substantial portions of the Software.
> +*
> +* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
> +* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
> +* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
> +* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
> +* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
> +* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
> +* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
> +*/
> +
> +#ifndef _FTW_H
> +#define        _FTW_H
> +
> +#ifdef __cplusplus
> +extern "C" {
> +#endif
> +
> +#ifdef _weak_alias(name, aliasname)
> +#  define _weak_alias(name, aliasname) \
> +  extern __typeof (name) aliasname __attribute__ ((__weak__, __alias__
> (#name)));
> +#endif
> +
> +#include <sys/features.h>
> +#include <sys/stat.h>
> +
> +#define FTW_F   1
> +#define FTW_D   2
> +#define FTW_DNR 3
> +#define FTW_NS  4
> +#define FTW_SL  5
> +#define FTW_DP  6
> +#define FTW_SLN 7
> +
> +#define FTW_PHYS  1
> +#define FTW_MOUNT 2
> +#define FTW_CHDIR 4
> +#define FTW_DEPTH 8
> +
> +struct FTW {
> +       int base;
> +       int level;
> +};
> +
> +int ftw(const char *, int (*)(const char *, const struct stat *, int),
> int);
> +int nftw(const char *, int (*)(const char *, const struct stat *, int,
> struct FTW *), int, int);
> +
> +#if defined(_LARGEFILE64_SOURCE) || defined(_GNU_SOURCE)
> +#define ftw64 ftw
> +#define nftw64 nftw
> +#endif
> +
> +#ifdef __cplusplus
> +}
> +#endif
> +
> +#endif
> diff --git a/newlib/libc/posix/Makefile.am b/newlib/libc/posix/Makefile.am
> index 6cdee1df0..5a358f782 100644
> --- a/newlib/libc/posix/Makefile.am
> +++ b/newlib/libc/posix/Makefile.am
> @@ -10,7 +10,7 @@ GENERAL_SOURCES = \
>         opendir.c readdir.c readdir_r.c \
>         regcomp.c regerror.c regexec.c regfree.c \
>         rewinddir.c sleep.c usleep.c \
> -       telldir.c
> +       telldir.c ftw.c nftw.c
>
>  ELIX_2_SOURCES = \
>          scandir.c seekdir.c
> diff --git a/newlib/libc/posix/ftw.c b/newlib/libc/posix/ftw.c
> new file mode 100644
> index 000000000..693be13d0
> --- /dev/null
> +++ b/newlib/libc/posix/ftw.c
> @@ -0,0 +1,34 @@
> +/*
> +* Copyright © 2005-2020 Rich Felker, et al.
> +*
> +* Permission is hereby granted, free of charge, to any person obtaining
> +* a copy of this software and associated documentation files (the
> +* "Software"), to deal in the Software without restriction, including
> +* without limitation the rights to use, copy, modify, merge, publish,
> +* distribute, sublicense, and/or sell copies of the Software, and to
> +* permit persons to whom the Software is furnished to do so, subject to
> +* the following conditions:
> +*
> +* The above copyright notice and this permission notice shall be
> +* included in all copies or substantial portions of the Software.
> +*
> +* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
> +* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
> +* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
> +* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
> +* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
> +* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
> +* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
> +*/
> +
> +#include <ftw.h>
> +
> +int ftw(const char *path, int (*fn)(const char *, const struct stat *,
> int), int fd_limit)
> +{
> +       /* The following cast assumes that calling a function with one
> +        * argument more than it needs behaves as expected. This is
> +        * actually undefined, but works on all real-world machines. */
> +       return nftw(path, (int (*)())fn, fd_limit, FTW_PHYS);
> +}
> +
> +_weak_alias(ftw, ftw64);
> diff --git a/newlib/libc/posix/nftw.c b/newlib/libc/posix/nftw.c
> new file mode 100644
> index 000000000..b78c13b7d
> --- /dev/null
> +++ b/newlib/libc/posix/nftw.c
> @@ -0,0 +1,156 @@
> +/*
> +* Copyright © 2005-2020 Rich Felker, et al.
> +*
> +* Permission is hereby granted, free of charge, to any person obtaining
> +* a copy of this software and associated documentation files (the
> +* "Software"), to deal in the Software without restriction, including
> +* without limitation the rights to use, copy, modify, merge, publish,
> +* distribute, sublicense, and/or sell copies of the Software, and to
> +* permit persons to whom the Software is furnished to do so, subject to
> +* the following conditions:
> +*
> +* The above copyright notice and this permission notice shall be
> +* included in all copies or substantial portions of the Software.
> +*
> +* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
> +* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
> +* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
> +* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
> +* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
> +* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
> +* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
> +*/
> +
> +#include <ftw.h>
> +#include <dirent.h>
> +#include <sys/stat.h>
> +#include <errno.h>
> +#include <unistd.h>
> +#include <string.h>
> +#include <limits.h>
> +#include <pthread.h>
> +
> +struct history
> +{
> +       struct history *chain;
> +       dev_t dev;
> +       ino_t ino;
> +       int level;
> +       int base;
> +};
> +
> +#undef dirfd
> +#define dirfd(d) (*(int *)d)
> +
> +static int do_nftw(char *path, int (*fn)(const char *, const struct stat
> *, int, struct FTW *), int fd_limit, int flags, struct history *h)
> +{
> +       size_t l = strlen(path), j = l && path[l-1]=='/' ? l-1 : l;
> +       struct stat st;
> +       struct history new;
> +       int type;
> +       int r;
> +       struct FTW lev;
> +
> +       if ((flags & FTW_PHYS) ? lstat(path, &st) : stat(path, &st) < 0) {
> +               if (!(flags & FTW_PHYS) && errno==ENOENT && !lstat(path,
> &st))
> +                       type = FTW_SLN;
> +               else if (errno != EACCES) return -1;
> +               else type = FTW_NS;
> +       } else if (S_ISDIR(st.st_mode)) {
> +               if (access(path, R_OK) < 0) type = FTW_DNR;
> +               else if (flags & FTW_DEPTH) type = FTW_DP;
> +               else type = FTW_D;
> +       } else if (S_ISLNK(st.st_mode)) {
> +               if (flags & FTW_PHYS) type = FTW_SL;
> +               else type = FTW_SLN;
> +       } else {
> +               type = FTW_F;
> +       }
> +
> +       if ((flags & FTW_MOUNT) && h && st.st_dev != h->dev)
> +               return 0;
> +
> +       new.chain = h;
> +       new.dev = st.st_dev;
> +       new.ino = st.st_ino;
> +       new.level = h ? h->level+1 : 0;
> +       new.base = j+1;
> +
> +       lev.level = new.level;
> +       if (h) {
> +               lev.base = h->base;
> +       } else {
> +               size_t k;
> +               for (k=j; k && path[k]=='/'; k--);
> +               for (; k && path[k-1]!='/'; k--);
> +               lev.base = k;
> +       }
> +
> +       if (!(flags & FTW_DEPTH) && (r=fn(path, &st, type, &lev)))
> +               return r;
> +
> +       for (; h; h = h->chain)
> +               if (h->dev == st.st_dev && h->ino == st.st_ino)
> +                       return 0;
> +
> +       if ((type == FTW_D || type == FTW_DP) && fd_limit) {
> +               DIR *d = opendir(path);
> +               if (d) {
> +                       struct dirent *de;
> +                       while ((de = readdir(d))) {
> +                               if (de->d_name[0] == '.'
> +                                && (!de->d_name[1]
> +                                 || (de->d_name[1]=='.'
> +                                  && !de->d_name[2]))) continue;
> +                               if (strlen(de->d_name) >= PATH_MAX-l) {
> +                                       errno = ENAMETOOLONG;
> +                                       closedir(d);
> +                                       return -1;
> +                               }
> +                               path[j]='/';
> +                               strcpy(path+j+1, de->d_name);
> +                               if ((r=do_nftw(path, fn, fd_limit-1,
> flags, &new))) {
> +                                       closedir(d);
> +                                       return r;
> +                               }
> +                       }
> +                       closedir(d);
> +               } else if (errno != EACCES) {
> +                       return -1;
> +               }
> +       }
> +
> +       path[l] = 0;
> +       if ((flags & FTW_DEPTH) && (r=fn(path, &st, type, &lev)))
> +               return r;
> +
> +       return 0;
> +}
> +
> +int nftw(const char *path, int (*fn)(const char *, const struct stat *,
> int, struct FTW *), int fd_limit, int flags)
> +{
> +       int r, cs;
> +       size_t l;
> +       char pathbuf[PATH_MAX+1];
> +
> +       if (fd_limit <= 0) return 0;
> +
> +       l = strlen(path);
> +       if (l > PATH_MAX) {
> +               errno = ENAMETOOLONG;
> +               return -1;
> +       }
> +       memcpy(pathbuf, path, l+1);
> +
> +#ifdef _STDIO_WITH_THREAD_CANCELLATION_SUPPORT
> +       pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
> +#endif
> +       r = do_nftw(pathbuf, fn, fd_limit, flags, NULL);
> +#ifdef _STDIO_WITH_THREAD_CANCELLATION_SUPPORT
> +       pthread_setcancelstate(cs, 0);
> +#endif
> +       return r;
> +}
> +
> +_weak_alias(nftw, nftw64);
> +
> --
> 2.25.1
>
>