Fix locating pdump by symlink

* admin/merge-gnulib (GNULIB_MODULES): Add canonicalize-lgpl module
* build-aux/config.guess, build-aux/gitlog-to-changelog,
build-aux/update-copyright, lib/canonicalize-lgpl.c,
lib/gnulib.mk.in, lib/malloca.c, lib/malloca.h, lib/pathmax.h,
m4/canonicalize.m4, m4/double-slash-root.m4, m4/gnulib-comp.m4,
m4/malloca.m4, my/pathmax.4: copy from GNUlib or regenerate from
update
* src/emacs.c: find dump by canonical path

1 files changed, 428 insertions, 0 deletions

diff --git a/lib/canonicalize-lgpl.c b/lib/canonicalize-lgpl.c
new file mode 100644
index 00000000000..4d1be6dc24b
--- /dev/null
+++ b/lib/canonicalize-lgpl.c
@@ -0,0 +1,428 @@
+/* Return the canonical absolute name of a given file.
+   Copyright (C) 1996-2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+#ifndef _LIBC
+/* Don't use __attribute__ __nonnull__ in this compilation unit.  Otherwise gcc
+   optimizes away the name == NULL test below.  */
+# define _GL_ARG_NONNULL(params)
+
+# define _GL_USE_STDLIB_ALLOC 1
+# include <config.h>
+#endif
+
+#if !HAVE_CANONICALIZE_FILE_NAME || !FUNC_REALPATH_WORKS || defined _LIBC
+
+/* Specification.  */
+#include <stdlib.h>
+
+#include <alloca.h>
+#include <string.h>
+#include <unistd.h>
+#include <limits.h>
+#if HAVE_SYS_PARAM_H || defined _LIBC
+# include <sys/param.h>
+#endif
+#include <sys/stat.h>
+#include <errno.h>
+#include <stddef.h>
+
+#ifdef _LIBC
+# include <shlib-compat.h>
+#else
+# define SHLIB_COMPAT(lib, introduced, obsoleted) 0
+# define versioned_symbol(lib, local, symbol, version) extern int dummy
+# define compat_symbol(lib, local, symbol, version)
+# define weak_alias(local, symbol)
+# define __canonicalize_file_name canonicalize_file_name
+# define __realpath realpath
+# include "pathmax.h"
+# include "malloca.h"
+# include "dosname.h"
+# if HAVE_GETCWD
+#  if IN_RELOCWRAPPER
+    /* When building the relocatable program wrapper, use the system's getcwd
+       function, not the gnulib override, otherwise we would get a link error.
+     */
+#   undef getcwd
+#  endif
+#  if defined VMS && !defined getcwd
+    /* We want the directory in Unix syntax, not in VMS syntax.
+       The gnulib override of 'getcwd' takes 2 arguments; the original VMS
+       'getcwd' takes 3 arguments.  */
+#   define __getcwd(buf, max) getcwd (buf, max, 0)
+#  else
+#   define __getcwd getcwd
+#  endif
+# else
+#  define __getcwd(buf, max) getwd (buf)
+# endif
+# define __readlink readlink
+# define __set_errno(e) errno = (e)
+# ifndef MAXSYMLINKS
+#  ifdef SYMLOOP_MAX
+#   define MAXSYMLINKS SYMLOOP_MAX
+#  else
+#   define MAXSYMLINKS 20
+#  endif
+# endif
+#endif
+
+#ifndef DOUBLE_SLASH_IS_DISTINCT_ROOT
+# define DOUBLE_SLASH_IS_DISTINCT_ROOT 0
+#endif
+
+/* Define this independently so that stdint.h is not a prerequisite.  */
+#ifndef SIZE_MAX
+# define SIZE_MAX ((size_t) -1)
+#endif
+
+#if !FUNC_REALPATH_WORKS || defined _LIBC
+
+static void
+alloc_failed (void)
+{
+#if defined _WIN32 && ! defined __CYGWIN__
+  /* Avoid errno problem without using the malloc or realloc modules; see:
+     https://lists.gnu.org/r/bug-gnulib/2016-08/msg00025.html  */
+  errno = ENOMEM;
+#endif
+}
+
+/* Return the canonical absolute name of file NAME.  A canonical name
+   does not contain any ".", ".." components nor any repeated path
+   separators ('/') or symlinks.  All path components must exist.  If
+   RESOLVED is null, the result is malloc'd; otherwise, if the
+   canonical name is PATH_MAX chars or more, returns null with 'errno'
+   set to ENAMETOOLONG; if the name fits in fewer than PATH_MAX chars,
+   returns the name in RESOLVED.  If the name cannot be resolved and
+   RESOLVED is non-NULL, it contains the path of the first component
+   that cannot be resolved.  If the path can be resolved, RESOLVED
+   holds the same value as the value returned.  */
+
+char *
+__realpath (const char *name, char *resolved)
+{
+  char *rpath, *dest, *extra_buf = NULL;
+  const char *start, *end, *rpath_limit;
+  long int path_max;
+  int num_links = 0;
+  size_t prefix_len;
+
+  if (name == NULL)
+    {
+      /* As per Single Unix Specification V2 we must return an error if
+         either parameter is a null pointer.  We extend this to allow
+         the RESOLVED parameter to be NULL in case the we are expected to
+         allocate the room for the return value.  */
+      __set_errno (EINVAL);
+      return NULL;
+    }
+
+  if (name[0] == '\0')
+    {
+      /* As per Single Unix Specification V2 we must return an error if
+         the name argument points to an empty string.  */
+      __set_errno (ENOENT);
+      return NULL;
+    }
+
+#ifdef PATH_MAX
+  path_max = PATH_MAX;
+#else
+  path_max = pathconf (name, _PC_PATH_MAX);
+  if (path_max <= 0)
+    path_max = 8192;
+#endif
+
+  if (resolved == NULL)
+    {
+      rpath = malloc (path_max);
+      if (rpath == NULL)
+        {
+          alloc_failed ();
+          return NULL;
+        }
+    }
+  else
+    rpath = resolved;
+  rpath_limit = rpath + path_max;
+
+  /* This is always zero for Posix hosts, but can be 2 for MS-Windows
+     and MS-DOS X:/foo/bar file names.  */
+  prefix_len = FILE_SYSTEM_PREFIX_LEN (name);
+
+  if (!IS_ABSOLUTE_FILE_NAME (name))
+    {
+      if (!__getcwd (rpath, path_max))
+        {
+          rpath[0] = '\0';
+          goto error;
+        }
+      dest = strchr (rpath, '\0');
+      start = name;
+      prefix_len = FILE_SYSTEM_PREFIX_LEN (rpath);
+    }
+  else
+    {
+      dest = rpath;
+      if (prefix_len)
+        {
+          memcpy (rpath, name, prefix_len);
+          dest += prefix_len;
+        }
+      *dest++ = '/';
+      if (DOUBLE_SLASH_IS_DISTINCT_ROOT)
+        {
+          if (ISSLASH (name[1]) && !ISSLASH (name[2]) && !prefix_len)
+            *dest++ = '/';
+          *dest = '\0';
+        }
+      start = name + prefix_len;
+    }
+
+  for (end = start; *start; start = end)
+    {
+#ifdef _LIBC
+      struct stat64 st;
+#else
+      struct stat st;
+#endif
+
+      /* Skip sequence of multiple path-separators.  */
+      while (ISSLASH (*start))
+        ++start;
+
+      /* Find end of path component.  */
+      for (end = start; *end && !ISSLASH (*end); ++end)
+        /* Nothing.  */;
+
+      if (end - start == 0)
+        break;
+      else if (end - start == 1 && start[0] == '.')
+        /* nothing */;
+      else if (end - start == 2 && start[0] == '.' && start[1] == '.')
+        {
+          /* Back up to previous component, ignore if at root already.  */
+          if (dest > rpath + prefix_len + 1)
+            for (--dest; dest > rpath && !ISSLASH (dest[-1]); --dest)
+              continue;
+          if (DOUBLE_SLASH_IS_DISTINCT_ROOT
+              && dest == rpath + 1 && !prefix_len
+              && ISSLASH (*dest) && !ISSLASH (dest[1]))
+            dest++;
+        }
+      else
+        {
+          size_t new_size;
+
+          if (!ISSLASH (dest[-1]))
+            *dest++ = '/';
+
+          if (dest + (end - start) >= rpath_limit)
+            {
+              ptrdiff_t dest_offset = dest - rpath;
+              char *new_rpath;
+
+              if (resolved)
+                {
+                  __set_errno (ENAMETOOLONG);
+                  if (dest > rpath + prefix_len + 1)
+                    dest--;
+                  *dest = '\0';
+                  goto error;
+                }
+              new_size = rpath_limit - rpath;
+              if (end - start + 1 > path_max)
+                new_size += end - start + 1;
+              else
+                new_size += path_max;
+              new_rpath = (char *) realloc (rpath, new_size);
+              if (new_rpath == NULL)
+                {
+                  alloc_failed ();
+                  goto error;
+                }
+              rpath = new_rpath;
+              rpath_limit = rpath + new_size;
+
+              dest = rpath + dest_offset;
+            }
+
+#ifdef _LIBC
+          dest = __mempcpy (dest, start, end - start);
+#else
+          memcpy (dest, start, end - start);
+          dest += end - start;
+#endif
+          *dest = '\0';
+
+          /* FIXME: if lstat fails with errno == EOVERFLOW,
+             the entry exists.  */
+#ifdef _LIBC
+          if (__lxstat64 (_STAT_VER, rpath, &st) < 0)
+#else
+          if (lstat (rpath, &st) < 0)
+#endif
+            goto error;
+
+          if (S_ISLNK (st.st_mode))
+            {
+              char *buf;
+              size_t len;
+              ssize_t n;
+
+              if (++num_links > MAXSYMLINKS)
+                {
+                  __set_errno (ELOOP);
+                  goto error;
+                }
+
+              buf = malloca (path_max);
+              if (!buf)
+                {
+                  __set_errno (ENOMEM);
+                  goto error;
+                }
+
+              n = __readlink (rpath, buf, path_max - 1);
+              if (n < 0)
+                {
+                  int saved_errno = errno;
+                  freea (buf);
+                  __set_errno (saved_errno);
+                  goto error;
+                }
+              buf[n] = '\0';
+
+              if (!extra_buf)
+                {
+                  extra_buf = malloca (path_max);
+                  if (!extra_buf)
+                    {
+                      freea (buf);
+                      __set_errno (ENOMEM);
+                      goto error;
+                    }
+                }
+
+              len = strlen (end);
+              /* Check that n + len + 1 doesn't overflow and is <= path_max. */
+              if (n >= SIZE_MAX - len || n + len >= path_max)
+                {
+                  freea (buf);
+                  __set_errno (ENAMETOOLONG);
+                  goto error;
+                }
+
+              /* Careful here, end may be a pointer into extra_buf... */
+              memmove (&extra_buf[n], end, len + 1);
+              name = end = memcpy (extra_buf, buf, n);
+
+              if (IS_ABSOLUTE_FILE_NAME (buf))
+                {
+                  size_t pfxlen = FILE_SYSTEM_PREFIX_LEN (buf);
+
+                  if (pfxlen)
+                    memcpy (rpath, buf, pfxlen);
+                  dest = rpath + pfxlen;
+                  *dest++ = '/'; /* It's an absolute symlink */
+                  if (DOUBLE_SLASH_IS_DISTINCT_ROOT)
+                    {
+                      if (ISSLASH (buf[1]) && !ISSLASH (buf[2]) && !pfxlen)
+                        *dest++ = '/';
+                      *dest = '\0';
+                    }
+                  /* Install the new prefix to be in effect hereafter.  */
+                  prefix_len = pfxlen;
+                }
+              else
+                {
+                  /* Back up to previous component, ignore if at root
+                     already: */
+                  if (dest > rpath + prefix_len + 1)
+                    for (--dest; dest > rpath && !ISSLASH (dest[-1]); --dest)
+                      continue;
+                  if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rpath + 1
+                      && ISSLASH (*dest) && !ISSLASH (dest[1]) && !prefix_len)
+                    dest++;
+                }
+            }
+          else if (!S_ISDIR (st.st_mode) && *end != '\0')
+            {
+              __set_errno (ENOTDIR);
+              goto error;
+            }
+        }
+    }
+  if (dest > rpath + prefix_len + 1 && ISSLASH (dest[-1]))
+    --dest;
+  if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rpath + 1 && !prefix_len
+      && ISSLASH (*dest) && !ISSLASH (dest[1]))
+    dest++;
+  *dest = '\0';
+
+  if (extra_buf)
+    freea (extra_buf);
+
+  return rpath;
+
+error:
+  {
+    int saved_errno = errno;
+    if (extra_buf)
+      freea (extra_buf);
+    if (resolved == NULL)
+      free (rpath);
+    __set_errno (saved_errno);
+  }
+  return NULL;
+}
+versioned_symbol (libc, __realpath, realpath, GLIBC_2_3);
+#endif /* !FUNC_REALPATH_WORKS || defined _LIBC */
+
+
+#if SHLIB_COMPAT(libc, GLIBC_2_0, GLIBC_2_3)
+char *
+attribute_compat_text_section
+__old_realpath (const char *name, char *resolved)
+{
+  if (resolved == NULL)
+    {
+      __set_errno (EINVAL);
+      return NULL;
+    }
+
+  return __realpath (name, resolved);
+}
+compat_symbol (libc, __old_realpath, realpath, GLIBC_2_0);
+#endif
+
+
+char *
+__canonicalize_file_name (const char *name)
+{
+  return __realpath (name, NULL);
+}
+weak_alias (__canonicalize_file_name, canonicalize_file_name)
+
+#else
+
+/* This declaration is solely to ensure that after preprocessing
+   this file is never empty.  */
+typedef int dummy;
+
+#endif