const unsigned char *buffer; /* pointer to cached file contents */
struct stat st; /* copy of stat(2) data for file */
int fd; /* fd open on file (short term storage only) */
+ int err_no; /* errno obtained if opening a file failed */
unsigned short include_count; /* number of times file has been read */
unsigned short refcnt; /* number of stacked buffers using this file */
unsigned char mapped; /* file buffer is mmapped */
static splay_tree_node find_or_create_entry PARAMS ((cpp_reader *,
const char *));
static void handle_missing_header PARAMS ((cpp_reader *, const char *, int));
+static int remove_component_p PARAMS ((const char *));
/* Set up the splay tree we use to store information about all the
file names seen in this compilation. We also have entries for each
}
/* Lookup a filename, which is simplified after making a copy, and
- create an entry if none exists. */
+ create an entry if none exists. errno is nonzero iff a (reported)
+ stat() error occurred during simplification. */
static splay_tree_node
find_or_create_entry (pfile, fname)
cpp_reader *pfile;
{
file = xcnew (struct include_file);
file->name = name;
+ file->err_no = errno;
node = splay_tree_insert (pfile->all_include_files,
(splay_tree_key) file->name,
(splay_tree_value) file);
splay_tree_node nd = find_or_create_entry (pfile, filename);
struct include_file *file = (struct include_file *) nd->value;
- /* Don't retry opening if we failed previously. */
- if (file->fd == -2)
- return 0;
+ if (file->err_no)
+ {
+ /* Ugh. handle_missing_header () needs errno to be set. */
+ errno = file->err_no;
+ return 0;
+ }
/* Don't reopen an idempotent file. */
if (DO_NOT_REREAD (file))
}
/* Don't issue an error message if the file doesn't exist. */
+ file->err_no = errno;
if (errno != ENOENT && errno != ENOTDIR)
cpp_error_from_errno (pfile, file->name);
- /* Create a negative node for this path, and return null. */
- file->fd = -2;
-
return 0;
}
p[len++] = '/';
}
memcpy (p + len, fname, fname_len + 1);
- _cpp_simplify_pathname (p);
deps_add_dep (pfile->deps, p);
}
}
return name;
}
+/* Returns true if it is safe to remove the final component of path,
+ when it is followed by a ".." component. We use lstat to avoid
+ symlinks if we have it. If not, we can still catch errors with
+ stat (). */
+static int
+remove_component_p (path)
+ const char *path;
+{
+ struct stat s;
+ int result;
+
+#ifdef HAVE_LSTAT
+ result = lstat (path, &s);
+#else
+ result = stat (path, &s);
+#endif
+
+ /* There's no guarantee that errno will be unchanged, even on
+ success. Cygwin's lstat(), for example, will often set errno to
+ ENOSYS. In case of success, reset errno to zero. */
+ if (result == 0)
+ errno = 0;
+
+ return result == 0 && S_ISDIR (s.st_mode);
+}
+
/* Simplify a path name in place, deleting redundant components. This
reduces OS overhead and guarantees that equivalent paths compare
the same (modulo symlinks).
/../quux /quux
//quux //quux (POSIX allows leading // as a namespace escape)
- Guarantees no trailing slashes. All transforms reduce the length
- of the string. Returns PATH;
- */
+ Guarantees no trailing slashes. All transforms reduce the length
+ of the string. Returns PATH. errno is 0 if no error occurred;
+ nonzero if an error occurred when using stat () or lstat (). */
+
char *
_cpp_simplify_pathname (path)
char *path;
{
- char *from, *to;
- char *base;
- int absolute = 0;
+#ifndef VMS
+ char *from, *to;
+ char *base, *orig_base;
+ int absolute = 0;
+
+ errno = 0;
+ /* Don't overflow the empty path by putting a '.' in it below. */
+ if (*path == '\0')
+ return path;
#if defined (HAVE_DOS_BASED_FILE_SYSTEM)
- /* Convert all backslashes to slashes. */
- for (from = path; *from; from++)
- if (*from == '\\') *from = '/';
+ /* Convert all backslashes to slashes. */
+ for (from = path; *from; from++)
+ if (*from == '\\') *from = '/';
- /* Skip over leading drive letter if present. */
- if (ISALPHA (path[0]) && path[1] == ':')
- from = to = &path[2];
- else
- from = to = path;
-#else
+ /* Skip over leading drive letter if present. */
+ if (ISALPHA (path[0]) && path[1] == ':')
+ from = to = &path[2];
+ else
from = to = path;
+#else
+ from = to = path;
#endif
- /* Remove redundant initial /s. */
- if (*from == '/')
+ /* Remove redundant leading /s. */
+ if (*from == '/')
{
- absolute = 1;
- to++;
- from++;
- if (*from == '/')
+ absolute = 1;
+ to++;
+ from++;
+ if (*from == '/')
{
- if (*++from == '/')
- /* 3 or more initial /s are equivalent to 1 /. */
- while (*++from == '/');
- else
- /* On some hosts // differs from /; Posix allows this. */
- to++;
+ if (*++from == '/')
+ /* 3 or more initial /s are equivalent to 1 /. */
+ while (*++from == '/');
+ else
+ /* On some hosts // differs from /; Posix allows this. */
+ to++;
}
}
- base = to;
-
- for (;;)
+
+ base = orig_base = to;
+ for (;;)
{
- while (*from == '/')
- from++;
-
- if (from[0] == '.' && from[1] == '/')
- from += 2;
- else if (from[0] == '.' && from[1] == '\0')
- goto done;
- else if (from[0] == '.' && from[1] == '.' && from[2] == '/')
+ int move_base = 0;
+
+ while (*from == '/')
+ from++;
+
+ if (*from == '\0')
+ break;
+
+ if (*from == '.')
{
- if (base == to)
+ if (from[1] == '\0')
+ break;
+ if (from[1] == '/')
{
- if (absolute)
- from += 3;
- else
- {
- *to++ = *from++;
- *to++ = *from++;
- *to++ = *from++;
- base = to;
- }
+ from += 2;
+ continue;
}
- else
+ else if (from[1] == '.' && (from[2] == '/' || from[2] == '\0'))
{
- to -= 2;
- while (to > base && *to != '/') to--;
- if (*to == '/')
- to++;
- from += 3;
- }
- }
- else if (from[0] == '.' && from[1] == '.' && from[2] == '\0')
- {
- if (base == to)
- {
- if (!absolute)
+ /* Don't simplify if there was no previous component. */
+ if (absolute && orig_base == to)
{
- *to++ = *from++;
- *to++ = *from++;
+ from += 2;
+ continue;
}
- }
- else
- {
- to -= 2;
- while (to > base && *to != '/') to--;
- if (*to == '/')
- to++;
- }
- goto done;
- }
- else
- /* Copy this component and trailing /, if any. */
- while ((*to++ = *from++) != '/')
- {
- if (!to[-1])
+ /* Don't simplify if the previous component was "../",
+ or if an error has already occurred with (l)stat. */
+ if (base != to && errno == 0)
{
- to--;
- goto done;
+ /* We don't back up if it's a symlink. */
+ *to = '\0';
+ if (remove_component_p (path))
+ {
+ while (to > base && *to != '/')
+ to--;
+ from += 2;
+ continue;
+ }
}
+ move_base = 1;
}
-
+ }
+
+ /* Add the component separator. */
+ if (to > orig_base)
+ *to++ = '/';
+
+ /* Copy this component until the trailing null or '/'. */
+ while (*from != '\0' && *from != '/')
+ *to++ = *from++;
+
+ if (move_base)
+ base = to;
}
- done:
- /* Trim trailing slash */
- if (to[0] == '/' && (!absolute || to > path+1))
- to--;
-
- /* Change the empty string to "." so that stat() on the result
- will always work. */
- if (to == path)
- *to++ = '.';
-
- *to = '\0';
-
- return path;
+ /* Change the empty string to "." so that it is not treated as stdin.
+ Null terminate. */
+ if (to == path)
+ *to++ = '.';
+ *to = '\0';
+
+ return path;
+#else /* VMS */
+ errno = 0;
+ return path;
+#endif /* !VMS */
}
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