Add bash 5.2 to third_party

third_party/bash/pathphys.c

@@ -0,0 +1,296 @@
+/* pathphys.c -- return pathname with all symlinks expanded. */
+
+/* Copyright (C) 2000-2020 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash, the Bourne Again SHell.
+
+   Bash 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.
+
+   Bash 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 Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "config.h"
+
+#include "bashtypes.h"
+#if defined (HAVE_SYS_PARAM_H)
+#  include <sys/param.h>
+#endif
+#include "posixstat.h"
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+
+#include "filecntl.h"
+#include "bashansi.h"
+#include <stdio.h>
+#include "chartypes.h"
+#include <errno.h>
+
+#include "shell.h"
+
+#if !defined (MAXSYMLINKS)
+#  define MAXSYMLINKS 32
+#endif
+
+#if !defined (errno)
+extern int errno;
+#endif /* !errno */
+
+extern char *get_working_directory PARAMS((char *));
+
+static int
+_path_readlink (path, buf, bufsiz)
+     char *path;
+     char *buf;
+     int bufsiz;
+{
+#ifdef HAVE_READLINK
+  return readlink (path, buf, bufsiz);
+#else
+  errno = EINVAL;
+  return -1;
+#endif
+}
+
+/* Look for ROOTEDPATH, PATHSEP, DIRSEP, and ISDIRSEP in ../../general.h */
+
+#define DOUBLE_SLASH(p)	((p[0] == '/') && (p[1] == '/') && p[2] != '/')
+
+/*
+ * Return PATH with all symlinks expanded in newly-allocated memory.
+ * This always gets an absolute pathname.
+ */
+
+char *
+sh_physpath (path, flags)
+     char *path;
+     int flags;
+{
+  char tbuf[PATH_MAX+1], linkbuf[PATH_MAX+1];
+  char *result, *p, *q, *qsave, *qbase, *workpath;
+  int double_slash_path, linklen, nlink;
+
+  linklen = strlen (path);
+
+#if 0
+  /* First sanity check -- punt immediately if the name is too long. */
+  if (linklen >= PATH_MAX)
+    return (savestring (path));
+#endif
+
+  nlink = 0;
+  q = result = (char *)xmalloc (PATH_MAX + 1);
+
+  /* Even if we get something longer than PATH_MAX, we might be able to
+     shorten it, so we try. */
+  if (linklen >= PATH_MAX)
+    workpath = savestring (path);
+  else
+    {
+      workpath = (char *)xmalloc (PATH_MAX + 1);
+      strcpy (workpath, path);
+    }
+
+  /* This always gets an absolute pathname. */
+
+  /* POSIX.2 says to leave a leading `//' alone.  On cygwin, we skip over any
+     leading `x:' (dos drive name). */
+#if defined (__CYGWIN__)
+  qbase = (ISALPHA((unsigned char)workpath[0]) && workpath[1] == ':') ? workpath + 3 : workpath + 1;
+#else
+  qbase = workpath + 1;
+#endif
+  double_slash_path = DOUBLE_SLASH (workpath);
+  qbase += double_slash_path;
+
+  for (p = workpath; p < qbase; )
+    *q++ = *p++;
+  qbase = q;
+
+  /*
+   * invariants:
+   *	  qbase points to the portion of the result path we want to modify
+   *      p points at beginning of path element we're considering.
+   *      q points just past the last path element we wrote (no slash).
+   *
+   * XXX -- need to fix error checking for too-long pathnames
+   */
+
+  while (*p)
+    {
+      if (ISDIRSEP(p[0])) /* null element */
+	p++;
+      else if(p[0] == '.' && PATHSEP(p[1]))	/* . and ./ */
+	p += 1; 	/* don't count the separator in case it is nul */
+      else if (p[0] == '.' && p[1] == '.' && PATHSEP(p[2])) /* .. and ../ */
+	{
+	  p += 2; /* skip `..' */
+	  if (q > qbase)
+	    {
+	      while (--q > qbase && ISDIRSEP(*q) == 0)
+		;
+	    }
+	}
+      else	/* real path element */
+	{
+	  /* add separator if not at start of work portion of result */
+	  qsave = q;
+	  if (q != qbase)
+	    *q++ = DIRSEP;
+	  while (*p && (ISDIRSEP(*p) == 0))
+	    {
+	      if (q - result >= PATH_MAX)
+		{
+#ifdef ENAMETOOLONG
+		  errno = ENAMETOOLONG;
+#else
+		  errno = EINVAL;
+#endif
+		  goto error;
+		}
+		
+	      *q++ = *p++;
+	    }
+
+	  *q = '\0';
+
+	  linklen = _path_readlink (result, linkbuf, PATH_MAX);
+	  if (linklen < 0)	/* if errno == EINVAL, it's not a symlink */
+	    {
+	      if (errno != EINVAL)
+		goto error;
+	      continue;
+	    }
+
+	  /* It's a symlink, and the value is in LINKBUF. */
+	  nlink++;
+	  if (nlink > MAXSYMLINKS)
+	    {
+#ifdef ELOOP
+	      errno = ELOOP;
+#else
+	      errno = EINVAL;
+#endif
+error:
+	      free (result);
+	      free (workpath);
+	      return ((char *)NULL);
+	    }
+
+	  linkbuf[linklen] = '\0';
+
+	  /* If the new path length would overrun PATH_MAX, punt now. */
+	  if ((strlen (p) + linklen + 2) >= PATH_MAX)
+	    {
+#ifdef ENAMETOOLONG
+	      errno = ENAMETOOLONG;
+#else
+	      errno = EINVAL;
+#endif
+	      goto error;
+	    }
+
+	  /* Form the new pathname by copying the link value to a temporary
+	     buffer and appending the rest of `workpath'.  Reset p to point
+	     to the start of the rest of the path.  If the link value is an
+	     absolute pathname, reset p, q, and qbase.  If not, reset p
+	     and q. */
+	  strcpy (tbuf, linkbuf);
+	  tbuf[linklen] = '/';
+	  strcpy (tbuf + linklen, p);
+	  strcpy (workpath, tbuf);
+
+	  if (ABSPATH(linkbuf))
+	    {
+	      q = result;
+	      /* Duplicating some code here... */
+#if defined (__CYGWIN__)
+	      qbase = (ISALPHA((unsigned char)workpath[0]) && workpath[1] == ':') ? workpath + 3 : workpath + 1;
+#else
+	      qbase = workpath + 1;
+#endif
+	      double_slash_path = DOUBLE_SLASH (workpath);
+	      qbase += double_slash_path;
+    
+	      for (p = workpath; p < qbase; )
+		*q++ = *p++;
+	      qbase = q;
+	    }
+	  else
+	    {
+	      p = workpath;
+	      q = qsave;
+	    }
+	}
+    }
+
+  *q = '\0';
+  free (workpath);
+
+  /* If the result starts with `//', but the original path does not, we
+     can turn the // into /.  Because of how we set `qbase', this should never
+     be true, but it's a sanity check. */
+  if (DOUBLE_SLASH(result) && double_slash_path == 0)
+    {
+      if (result[2] == '\0')	/* short-circuit for bare `//' */
+	result[1] = '\0';
+      else
+	memmove (result, result + 1, strlen (result + 1) + 1);
+    }
+
+  return (result);
+}
+
+char *
+sh_realpath (pathname, resolved)
+     const char *pathname;
+     char *resolved;
+{
+  char *tdir, *wd;
+
+  if (pathname == 0 || *pathname == '\0')
+    {
+      errno = (pathname == 0) ? EINVAL : ENOENT;
+      return ((char *)NULL);
+    }
+
+  if (ABSPATH (pathname) == 0)
+    {
+      wd = get_working_directory ("sh_realpath");
+      if (wd == 0)
+	return ((char *)NULL);
+      tdir = sh_makepath (wd, (char *)pathname, 0);
+      free (wd);
+    }
+  else
+    tdir = savestring (pathname);
+
+  wd = sh_physpath (tdir, 0);
+  free (tdir);
+
+  if (resolved == 0)
+    return (wd);
+
+  if (wd)
+    {
+      strncpy (resolved, wd, PATH_MAX - 1);
+      resolved[PATH_MAX - 1] = '\0';
+      free (wd);
+      return resolved;
+    }
+  else
+    {
+      resolved[0] = '\0';
+      return wd;
+    }
+}