diff options
Diffstat (limited to 'Python/import.c')
| -rw-r--r-- | Python/import.c | 391 |
1 files changed, 363 insertions, 28 deletions
diff --git a/Python/import.c b/Python/import.c index b046362..1cddcb0 100644 --- a/Python/import.c +++ b/Python/import.c @@ -43,6 +43,15 @@ typedef unsigned short mode_t; The current working scheme is to increment the previous value by 10. + Starting with the adoption of PEP 3147 in Python 3.2, every bump in magic + number also includes a new "magic tag", i.e. a human readable string used + to represent the magic number in __pycache__ directories. When you change + the magic number, you must also set a new unique magic tag. Generally this + can be named after the Python major version of the magic number bump, but + it can really be anything, as long as it's different than anything else + that's come before. The tags are included in the following table, starting + with Python 3.2a0. + Known values: Python 1.5: 20121 Python 1.5.1: 20121 @@ -91,11 +100,18 @@ typedef unsigned short mode_t; Python 3.1a0: 3151 (optimize conditional branches: introduce POP_JUMP_IF_FALSE and POP_JUMP_IF_TRUE) Python 3.2a0: 3160 (add SETUP_WITH) + tag: cpython-32 */ +/* If you change MAGIC, you must change TAG and you must insert the old value + into _PyMagicNumberTags below. +*/ #define MAGIC (3160 | ((long)'\r'<<16) | ((long)'\n'<<24)) -/* Magic word as global */ +#define TAG "cpython-32" +#define CACHEDIR "__pycache__" +/* Current magic word and string tag as globals. */ static long pyc_magic = MAGIC; +static const char *pyc_tag = TAG; /* See _PyImport_FixupExtension() below */ static PyObject *extensions = NULL; @@ -517,7 +533,7 @@ PyImport_Cleanup(void) } -/* Helper for pythonrun.c -- return magic number */ +/* Helper for pythonrun.c -- return magic number and tag. */ long PyImport_GetMagicNumber(void) @@ -526,6 +542,12 @@ PyImport_GetMagicNumber(void) } +const char * +PyImport_GetMagicTag(void) +{ + return pyc_tag; +} + /* Magic for extension modules (built-in as well as dynamically loaded). To prevent initializing an extension module more than once, we keep a static dictionary 'extensions' keyed by module name @@ -671,7 +693,10 @@ remove_module(const char *name) "sys.modules failed"); } -static PyObject * get_sourcefile(const char *file); +static PyObject * get_sourcefile(char *file); +static char *make_source_pathname(char *pathname, char *buf); +static char *make_compiled_pathname(char *pathname, char *buf, size_t buflen, + int debug); /* Execute a code object in a module and return the module object * WITH INCREMENTED REFERENCE COUNT. If an error occurs, name is @@ -679,16 +704,28 @@ static PyObject * get_sourcefile(const char *file); * in sys.modules. The caller may wish to restore the original * module object (if any) in this case; PyImport_ReloadModule is an * example. + * + * Note that PyImport_ExecCodeModuleWithPathnames() is the preferred, richer + * interface. The other two exist primarily for backward compatibility. */ PyObject * PyImport_ExecCodeModule(char *name, PyObject *co) { - return PyImport_ExecCodeModuleEx(name, co, (char *)NULL); + return PyImport_ExecCodeModuleWithPathnames( + name, co, (char *)NULL, (char *)NULL); } PyObject * PyImport_ExecCodeModuleEx(char *name, PyObject *co, char *pathname) { + return PyImport_ExecCodeModuleWithPathnames( + name, co, pathname, (char *)NULL); +} + +PyObject * +PyImport_ExecCodeModuleWithPathnames(char *name, PyObject *co, char *pathname, + char *cpathname) +{ PyObject *modules = PyImport_GetModuleDict(); PyObject *m, *d, *v; @@ -718,6 +755,20 @@ PyImport_ExecCodeModuleEx(char *name, PyObject *co, char *pathname) PyErr_Clear(); /* Not important enough to report */ Py_DECREF(v); + /* Remember the pyc path name as the __cached__ attribute. */ + if (cpathname == NULL) { + v = Py_None; + Py_INCREF(v); + } + else if ((v = PyUnicode_FromString(cpathname)) == NULL) { + PyErr_Clear(); /* Not important enough to report */ + v = Py_None; + Py_INCREF(v); + } + if (PyDict_SetItemString(d, "__cached__", v) != 0) + PyErr_Clear(); /* Not important enough to report */ + Py_DECREF(v); + v = PyEval_EvalCode((PyCodeObject *)co, d, d); if (v == NULL) goto error; @@ -740,32 +791,189 @@ PyImport_ExecCodeModuleEx(char *name, PyObject *co, char *pathname) } +/* Like strrchr(string, '/') but searches for the rightmost of either SEP + or ALTSEP, if the latter is defined. +*/ +static char * +rightmost_sep(char *s) +{ + char *found, c; + for (found = NULL; (c = *s); s++) { + if (c == SEP +#ifdef ALTSEP + || c == ALTSEP +#endif + ) + { + found = s; + } + } + return found; +} + + /* Given a pathname for a Python source file, fill a buffer with the pathname for the corresponding compiled file. Return the pathname for the compiled file, or NULL if there's no space in the buffer. Doesn't set an exception. */ static char * -make_compiled_pathname(char *pathname, char *buf, size_t buflen) +make_compiled_pathname(char *pathname, char *buf, size_t buflen, int debug) { + /* foo.py -> __pycache__/foo.<tag>.pyc */ size_t len = strlen(pathname); - if (len+2 > buflen) + size_t i, save; + char *pos; + int sep = SEP; + + /* Sanity check that the buffer has roughly enough space to hold what + will eventually be the full path to the compiled file. The 5 extra + bytes include the slash afer __pycache__, the two extra dots, the + extra trailing character ('c' or 'o') and null. This isn't exact + because the contents of the buffer can affect how many actual + characters of the string get into the buffer. We'll do a final + sanity check before writing the extension to ensure we do not + overflow the buffer. + */ + if (len + strlen(CACHEDIR) + strlen(pyc_tag) + 5 > buflen) return NULL; -#ifdef MS_WINDOWS - /* Treat .pyw as if it were .py. The case of ".pyw" must match - that used in _PyImport_StandardFiletab. */ - if (len >= 4 && strcmp(&pathname[len-4], ".pyw") == 0) - --len; /* pretend 'w' isn't there */ + /* Find the last path separator and copy everything from the start of + the source string up to and including the separator. + */ + if ((pos = rightmost_sep(pathname)) == NULL) { + i = 0; + } + else { + sep = *pos; + i = pos - pathname + 1; + strncpy(buf, pathname, i); + } + + save = i; + buf[i++] = '\0'; + /* Add __pycache__/ */ + strcat(buf, CACHEDIR); + i += strlen(CACHEDIR) - 1; + buf[i++] = sep; + buf[i++] = '\0'; + /* Add the base filename, but remove the .py or .pyw extension, since + the tag name must go before the extension. + */ + strcat(buf, pathname + save); + if ((pos = strrchr(buf, '.')) != NULL) + *++pos = '\0'; + strcat(buf, pyc_tag); + /* The length test above assumes that we're only adding one character + to the end of what would normally be the extension. What if there + is no extension, or the string ends in '.' or '.p', and otherwise + fills the buffer? By appending 4 more characters onto the string + here, we could overrun the buffer. + + As a simple example, let's say buflen=32 and the input string is + 'xxx.py'. strlen() would be 6 and the test above would yield: + + (6 + 11 + 10 + 5 == 32) > 32 + + which is false and so the name mangling would continue. This would + be fine because we'd end up with this string in buf: + + __pycache__/xxx.cpython-32.pyc\0 + + strlen(of that) == 30 + the nul fits inside a 32 character buffer. + We can even handle an input string of say 'xxxxx' above because + that's (5 + 11 + 10 + 5 == 31) > 32 which is also false. Name + mangling that yields: + + __pycache__/xxxxxcpython-32.pyc\0 + + which is 32 characters including the nul, and thus fits in the + buffer. However, an input string of 'xxxxxx' would yield a result + string of: + + __pycache__/xxxxxxcpython-32.pyc\0 + + which is 33 characters long (including the nul), thus overflowing + the buffer, even though the first test would fail, i.e.: the input + string is also 6 characters long, so 32 > 32 is false. + + The reason the first test fails but we still overflow the buffer is + that the test above only expects to add one extra character to be + added to the extension, and here we're adding three (pyc). We + don't add the first dot, so that reclaims one of expected + positions, leaving us overflowing by 1 byte (3 extra - 1 reclaimed + dot - 1 expected extra == 1 overflowed). + + The best we can do is ensure that we still have enough room in the + target buffer before we write the extension. Because it's always + only the extension that can cause the overflow, and never the other + path bytes we've written, it's sufficient to just do one more test + here. Still, the assertion that follows can't hurt. + */ +#if 0 + printf("strlen(buf): %d; buflen: %d\n", (int)strlen(buf), (int)buflen); #endif - memcpy(buf, pathname, len); - buf[len] = Py_OptimizeFlag ? 'o' : 'c'; - buf[len+1] = '\0'; - + if (strlen(buf) + 5 > buflen) + return NULL; + strcat(buf, debug ? ".pyc" : ".pyo"); + assert(strlen(buf) < buflen); return buf; } +/* Given a pathname to a Python byte compiled file, return the path to the + source file, if the path matches the PEP 3147 format. This does not check + for any file existence, however, if the pyc file name does not match PEP + 3147 style, NULL is returned. buf must be at least as big as pathname; + the resulting path will always be shorter. */ + +static char * +make_source_pathname(char *pathname, char *buf) +{ + /* __pycache__/foo.<tag>.pyc -> foo.py */ + size_t i, j; + char *left, *right, *dot0, *dot1, sep; + + /* Look back two slashes from the end. In between these two slashes + must be the string __pycache__ or this is not a PEP 3147 style + path. It's possible for there to be only one slash. + */ + if ((right = rightmost_sep(pathname)) == NULL) + return NULL; + sep = *right; + *right = '\0'; + left = rightmost_sep(pathname); + *right = sep; + if (left == NULL) + left = pathname; + else + left++; + if (right-left != strlen(CACHEDIR) || + strncmp(left, CACHEDIR, right-left) != 0) + return NULL; + + /* Now verify that the path component to the right of the last slash + has two dots in it. + */ + if ((dot0 = strchr(right + 1, '.')) == NULL) + return NULL; + if ((dot1 = strchr(dot0 + 1, '.')) == NULL) + return NULL; + /* Too many dots? */ + if (strchr(dot1 + 1, '.') != NULL) + return NULL; + + /* This is a PEP 3147 path. Start by copying everything from the + start of pathname up to and including the leftmost slash. Then + copy the file's basename, removing the magic tag and adding a .py + suffix. + */ + strncpy(buf, pathname, (i=left-pathname)); + strncpy(buf+i, right+1, (j=dot0-right)); + strcpy(buf+i+j, "py"); + return buf; +} + /* Given a pathname for a Python source file, its time of last modification, and a pathname for a compiled file, check whether the compiled file represents the same version of the source. If so, @@ -846,7 +1054,8 @@ load_compiled_module(char *name, char *cpathname, FILE *fp) if (Py_VerboseFlag) PySys_WriteStderr("import %s # precompiled from %s\n", name, cpathname); - m = PyImport_ExecCodeModuleEx(name, (PyObject *)co, cpathname); + m = PyImport_ExecCodeModuleWithPathnames( + name, (PyObject *)co, cpathname, cpathname); Py_DECREF(co); return m; @@ -919,12 +1128,41 @@ static void write_compiled_module(PyCodeObject *co, char *cpathname, struct stat *srcstat) { FILE *fp; + char *dirpath; time_t mtime = srcstat->st_mtime; #ifdef MS_WINDOWS /* since Windows uses different permissions */ mode_t mode = srcstat->st_mode & ~S_IEXEC; + mode_t dirmode = srcstat->st_mode | S_IEXEC; /* XXX Is this correct + for Windows? + 2010-04-07 BAW */ #else mode_t mode = srcstat->st_mode & ~S_IXUSR & ~S_IXGRP & ~S_IXOTH; + mode_t dirmode = (srcstat->st_mode | + S_IXUSR | S_IXGRP | S_IXOTH | + S_IWUSR | S_IWGRP | S_IWOTH); #endif + int saved; + + /* Ensure that the __pycache__ directory exists. */ + dirpath = rightmost_sep(cpathname); + if (dirpath == NULL) { + if (Py_VerboseFlag) + PySys_WriteStderr( + "# no %s path found %s\n", + CACHEDIR, cpathname); + return; + } + saved = *dirpath; + *dirpath = '\0'; + /* XXX call os.mkdir() or maybe CreateDirectoryA() on Windows? */ + if (mkdir(cpathname, dirmode) < 0 && errno != EEXIST) { + *dirpath = saved; + if (Py_VerboseFlag) + PySys_WriteStderr( + "# cannot create cache dir %s\n", cpathname); + return; + } + *dirpath = saved; fp = open_exclusive(cpathname, mode); if (fp == NULL) { @@ -1032,8 +1270,8 @@ load_source_module(char *name, char *pathname, FILE *fp) return NULL; } #endif - cpathname = make_compiled_pathname(pathname, buf, - (size_t)MAXPATHLEN + 1); + cpathname = make_compiled_pathname( + pathname, buf, (size_t)MAXPATHLEN + 1, !Py_OptimizeFlag); if (cpathname != NULL && (fpc = check_compiled_module(pathname, st.st_mtime, cpathname))) { co = read_compiled_module(cpathname, fpc); @@ -1060,7 +1298,8 @@ load_source_module(char *name, char *pathname, FILE *fp) write_compiled_module(co, cpathname, &st); } } - m = PyImport_ExecCodeModuleEx(name, (PyObject *)co, pathname); + m = PyImport_ExecCodeModuleWithPathnames( + name, (PyObject *)co, pathname, cpathname); Py_DECREF(co); return m; @@ -1070,7 +1309,7 @@ load_source_module(char *name, char *pathname, FILE *fp) * Returns the path to the py file if available, else the given path */ static PyObject * -get_sourcefile(const char *file) +get_sourcefile(char *file) { char py[MAXPATHLEN + 1]; Py_ssize_t len; @@ -1087,8 +1326,15 @@ get_sourcefile(const char *file) return PyUnicode_DecodeFSDefault(file); } - strncpy(py, file, len-1); - py[len-1] = '\0'; + /* Start by trying to turn PEP 3147 path into source path. If that + * fails, just chop off the trailing character, i.e. legacy pyc path + * to py. + */ + if (make_source_pathname(file, py) == NULL) { + strncpy(py, file, len-1); + py[len-1] = '\0'; + } + if (stat(py, &statbuf) == 0 && S_ISREG(statbuf.st_mode)) { u = PyUnicode_DecodeFSDefault(py); @@ -2813,16 +3059,28 @@ PyImport_Import(PyObject *module_name) */ static PyObject * -imp_get_magic(PyObject *self, PyObject *noargs) +imp_make_magic(long magic) { char buf[4]; - buf[0] = (char) ((pyc_magic >> 0) & 0xff); - buf[1] = (char) ((pyc_magic >> 8) & 0xff); - buf[2] = (char) ((pyc_magic >> 16) & 0xff); - buf[3] = (char) ((pyc_magic >> 24) & 0xff); + buf[0] = (char) ((magic >> 0) & 0xff); + buf[1] = (char) ((magic >> 8) & 0xff); + buf[2] = (char) ((magic >> 16) & 0xff); + buf[3] = (char) ((magic >> 24) & 0xff); return PyBytes_FromStringAndSize(buf, 4); +}; + +static PyObject * +imp_get_magic(PyObject *self, PyObject *noargs) +{ + return imp_make_magic(pyc_magic); +} + +static PyObject * +imp_get_tag(PyObject *self, PyObject *noargs) +{ + return PyUnicode_FromString(pyc_tag); } static PyObject * @@ -3190,6 +3448,75 @@ PyDoc_STRVAR(doc_reload, \n\ Reload the module. The module must have been successfully imported before."); +static PyObject * +imp_cache_from_source(PyObject *self, PyObject *args, PyObject *kws) +{ + static char *kwlist[] = {"path", "debug_override", NULL}; + + char buf[MAXPATHLEN+1]; + char *pathname, *cpathname; + PyObject *debug_override = Py_None; + int debug = !Py_OptimizeFlag; + + if (!PyArg_ParseTupleAndKeywords( + args, kws, "es|O", kwlist, + Py_FileSystemDefaultEncoding, &pathname, &debug_override)) + return NULL; + + if (debug_override != Py_None) + if ((debug = PyObject_IsTrue(debug_override)) < 0) + return NULL; + + cpathname = make_compiled_pathname(pathname, buf, MAXPATHLEN+1, debug); + PyMem_Free(pathname); + + if (cpathname == NULL) { + PyErr_Format(PyExc_SystemError, "path buffer too short"); + return NULL; + } + return PyUnicode_FromString(buf); +} + +PyDoc_STRVAR(doc_cache_from_source, +"Given the path to a .py file, return the path to its .pyc/.pyo file.\n\ +\n\ +The .py file does not need to exist; this simply returns the path to the\n\ +.pyc/.pyo file calculated as if the .py file were imported. The extension\n\ +will be .pyc unless __debug__ is not defined, then it will be .pyo.\n\ +\n\ +If debug_override is not None, then it must be a boolean and is taken as\n\ +the value of __debug__ instead."); + +static PyObject * +imp_source_from_cache(PyObject *self, PyObject *args, PyObject *kws) +{ + static char *kwlist[] = {"path", NULL}; + + char *pathname; + char buf[MAXPATHLEN+1]; + + if (!PyArg_ParseTupleAndKeywords( + args, kws, "es", kwlist, + Py_FileSystemDefaultEncoding, &pathname)) + return NULL; + + if (make_source_pathname(pathname, buf) == NULL) { + PyErr_Format(PyExc_ValueError, "Not a PEP 3147 pyc path: %s", + pathname); + PyMem_Free(pathname); + return NULL; + } + PyMem_Free(pathname); + return PyUnicode_FromString(buf); +} + +PyDoc_STRVAR(doc_source_from_cache, +"Given the path to a .pyc./.pyo file, return the path to its .py file.\n\ +\n\ +The .pyc/.pyo file does not need to exist; this simply returns the path to\n\ +the .py file calculated to correspond to the .pyc/.pyo file. If path\n\ +does not conform to PEP 3147 format, ValueError will be raised."); + /* Doc strings */ PyDoc_STRVAR(doc_imp, @@ -3212,6 +3539,10 @@ PyDoc_STRVAR(doc_get_magic, "get_magic() -> string\n\ Return the magic number for .pyc or .pyo files."); +PyDoc_STRVAR(doc_get_tag, +"get_tag() -> string\n\ +Return the magic tag for .pyc or .pyo files."); + PyDoc_STRVAR(doc_get_suffixes, "get_suffixes() -> [(suffix, mode, type), ...]\n\ Return a list of (suffix, mode, type) tuples describing the files\n\ @@ -3242,6 +3573,7 @@ On platforms without threads, this function does nothing."); static PyMethodDef imp_methods[] = { {"find_module", imp_find_module, METH_VARARGS, doc_find_module}, {"get_magic", imp_get_magic, METH_NOARGS, doc_get_magic}, + {"get_tag", imp_get_tag, METH_NOARGS, doc_get_tag}, {"get_suffixes", imp_get_suffixes, METH_NOARGS, doc_get_suffixes}, {"load_module", imp_load_module, METH_VARARGS, doc_load_module}, {"new_module", imp_new_module, METH_VARARGS, doc_new_module}, @@ -3249,6 +3581,10 @@ static PyMethodDef imp_methods[] = { {"acquire_lock", imp_acquire_lock, METH_NOARGS, doc_acquire_lock}, {"release_lock", imp_release_lock, METH_NOARGS, doc_release_lock}, {"reload", imp_reload, METH_O, doc_reload}, + {"cache_from_source", (PyCFunction)imp_cache_from_source, + METH_VARARGS | METH_KEYWORDS, doc_cache_from_source}, + {"source_from_cache", (PyCFunction)imp_source_from_cache, + METH_VARARGS | METH_KEYWORDS, doc_source_from_cache}, /* The rest are obsolete */ {"get_frozen_object", imp_get_frozen_object, METH_VARARGS}, {"is_frozen_package", imp_is_frozen_package, METH_VARARGS}, @@ -3436,7 +3772,6 @@ PyInit_imp(void) failure: Py_XDECREF(m); return NULL; - } |