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-rw-r--r--meta/lib/oe/path.py87
1 files changed, 87 insertions, 0 deletions
diff --git a/meta/lib/oe/path.py b/meta/lib/oe/path.py
index ea58bedc8b..0b34cebdab 100644
--- a/meta/lib/oe/path.py
+++ b/meta/lib/oe/path.py
@@ -2,6 +2,7 @@ import errno
2import glob 2import glob
3import shutil 3import shutil
4import subprocess 4import subprocess
5import os.path
5 6
6def join(*paths): 7def join(*paths):
7 """Like os.path.join but doesn't treat absolute RHS specially""" 8 """Like os.path.join but doesn't treat absolute RHS specially"""
@@ -161,3 +162,89 @@ def find(dir, **walkoptions):
161 for root, dirs, files in os.walk(dir, **walkoptions): 162 for root, dirs, files in os.walk(dir, **walkoptions):
162 for file in files: 163 for file in files:
163 yield os.path.join(root, file) 164 yield os.path.join(root, file)
165
166
167## realpath() related functions
168def __is_path_below(file, root):
169 return (file + os.path.sep).startswith(root)
170
171def __realpath_rel(start, rel_path, root, loop_cnt):
172 """Calculates real path of symlink 'start' + 'rel_path' below
173 'root'; no part of 'start' below 'root' must contain symlinks. """
174 have_dir = True
175
176 for d in rel_path.split(os.path.sep):
177 if not have_dir:
178 raise OSError(errno.ENOENT, "no such directory %s" % start)
179
180 if d == os.path.pardir: # '..'
181 if len(start) >= len(root):
182 # do not follow '..' before root
183 start = os.path.dirname(start)
184 else:
185 # emit warning?
186 pass
187 else:
188 (start, have_dir) = __realpath(os.path.join(start, d),
189 root, loop_cnt)
190
191 assert(__is_path_below(start, root))
192
193 return start
194
195def __realpath(file, root, loop_cnt):
196 while os.path.islink(file) and len(file) >= len(root):
197 if loop_cnt == 0:
198 raise OSError(errno.ELOOP, file)
199
200 loop_cnt -= 1
201 target = os.path.normpath(os.readlink(file))
202
203 if not os.path.isabs(target):
204 tdir = os.path.dirname(file)
205 assert(__is_path_below(tdir, root))
206 else:
207 tdir = root
208
209 file = __realpath_rel(tdir, target, root, loop_cnt)
210
211 try:
212 is_dir = os.path.isdir(file)
213 except:
214 is_dir = false
215
216 return (file, is_dir)
217
218def realpath(file, root, use_physdir = True, loop_cnt = 100):
219 """ Returns the canonical path of 'file' with assuming a toplevel
220 'root' directory. When 'use_physdir' is set, all preceding path
221 components of 'file' will be resolved first; this flag should be
222 set unless it is guaranteed that there is no symlink in the path."""
223
224 root = os.path.normpath(root)
225 file = os.path.normpath(file)
226
227 if not root.endswith(os.path.sep):
228 # letting root end with '/' makes some things easier
229 root = root + os.path.sep
230
231 if not __is_path_below(file, root):
232 raise OSError(errno.EINVAL, "file '%s' is not below root" % file)
233
234 try:
235 if use_physdir:
236 file = __realpath_rel(root, file[(len(root) - 1):], root, loop_cnt)
237 else:
238 file = __realpath(file, root, loop_cnt)[0]
239 except OSError, e:
240 if e.errno == errno.ELOOP:
241 # make ELOOP more readable; without catching it, there will
242 # be printed a backtrace with 100s of OSError exceptions
243 # else
244 raise OSError(errno.ELOOP,
245 "too much recursions while resolving '%s'; loop in '%s'" %
246 (file, e.strerror))
247
248 raise
249
250 return file