Staging
v0.8.1
v0.8.1
https://github.com/python/cpython
Tip revision: 74f4bd53e03ded8408bcc2de67cf0f5a4ac5b1a1 authored by Barry Warsaw on 23 February 2012, 15:59:38 UTC
Bump some more copyright years (as per PEP 101), since this is the first
Bump some more copyright years (as per PEP 101), since this is the first
Tip revision: 74f4bd5
getpathp.c
/* Return the initial module search path. */
/* Used by DOS, OS/2, Windows 3.1. Works on NT too. */
#include "Python.h"
#include "osdefs.h"
#ifdef MS_WIN32
#include <windows.h>
extern BOOL PyWin_IsWin32s(void);
#endif
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif /* HAVE_UNISTD_H */
/* Search in some common locations for the associated Python libraries.
*
* Two directories must be found, the platform independent directory
* (prefix), containing the common .py and .pyc files, and the platform
* dependent directory (exec_prefix), containing the shared library
* modules. Note that prefix and exec_prefix can be the same directory,
* but for some installations, they are different.
*
* Py_GetPath() tries to return a sensible Python module search path.
*
* First, we look to see if the executable is in a subdirectory of
* the Python build directory. We calculate the full path of the
* directory containing the executable as progpath. We work backwards
* along progpath and look for $dir/Modules/Setup.in, a distinctive
* landmark. If found, we use $dir/Lib as $root. The returned
* Python path is the compiled #define PYTHONPATH with all the initial
* "./lib" replaced by $root.
*
* Otherwise, if there is a PYTHONPATH environment variable, we return that.
*
* Otherwise we try to find $progpath/lib/os.py, and if found, then
* root is $progpath/lib, and we return Python path as compiled PYTHONPATH
* with all "./lib" replaced by $root (as above).
*
*/
#ifndef LANDMARK
#define LANDMARK "lib\\os.py"
#endif
static char prefix[MAXPATHLEN+1];
static char exec_prefix[MAXPATHLEN+1];
static char progpath[MAXPATHLEN+1];
static char *module_search_path = NULL;
static int
is_sep(char ch) /* determine if "ch" is a separator character */
{
#ifdef ALTSEP
return ch == SEP || ch == ALTSEP;
#else
return ch == SEP;
#endif
}
static void
reduce(char *dir)
{
int i = strlen(dir);
while (i > 0 && !is_sep(dir[i]))
--i;
dir[i] = '\0';
}
static int
exists(char *filename)
{
struct stat buf;
return stat(filename, &buf) == 0;
}
/* Add a path component, by appending stuff to buffer.
buffer must have at least MAXPATHLEN + 1 bytes allocated, and contain a
NUL-terminated string with no more than MAXPATHLEN characters (not counting
the trailing NUL). It's a fatal error if it contains a string longer than
that (callers must be careful!). If these requirements are met, it's
guaranteed that buffer will still be a NUL-terminated string with no more
than MAXPATHLEN characters at exit. If stuff is too long, only as much of
stuff as fits will be appended.
*/
static void
join(char *buffer, char *stuff)
{
int n, k;
if (is_sep(stuff[0]))
n = 0;
else {
n = strlen(buffer);
if (n > 0 && !is_sep(buffer[n-1]) && n < MAXPATHLEN)
buffer[n++] = SEP;
}
if (n > MAXPATHLEN)
Py_FatalError("buffer overflow in getpathp.c's joinpath()");
k = strlen(stuff);
if (n + k > MAXPATHLEN)
k = MAXPATHLEN - n;
strncpy(buffer+n, stuff, k);
buffer[n+k] = '\0';
}
static int
search_for_prefix(char *argv0_path, char *landmark)
{
int n;
/* Search from argv0_path, until root is found */
strcpy(prefix, argv0_path);
do {
n = strlen(prefix);
join(prefix, landmark);
if (exists(prefix)) {
prefix[n] = '\0';
return 1;
}
prefix[n] = '\0';
reduce(prefix);
} while (prefix[0]);
return 0;
}
#ifdef MS_WIN32
#include "malloc.h" // for alloca - see comments below!
extern const char *PyWin_DLLVersionString; // a string loaded from the DLL at startup.
/* Load a PYTHONPATH value from the registry.
Load from either HKEY_LOCAL_MACHINE or HKEY_CURRENT_USER.
Returns NULL, or a pointer that should be freed.
*/
static char *
getpythonregpath(HKEY keyBase, BOOL bWin32s)
{
HKEY newKey = 0;
DWORD nameSize = 0;
DWORD dataSize = 0;
DWORD numEntries = 0;
LONG rc;
char *retval = NULL;
char *dataBuf;
const char keyPrefix[] = "Software\\Python\\PythonCore\\";
const char keySuffix[] = "\\PythonPath";
int versionLen;
char *keyBuf;
// Tried to use sysget("winver") but here is too early :-(
versionLen = strlen(PyWin_DLLVersionString);
// alloca == no free required, but memory only local to fn.
// also no heap fragmentation! Am I being silly?
keyBuf = alloca(sizeof(keyPrefix)-1 + versionLen + sizeof(keySuffix)); // chars only, plus 1 NULL.
// lots of constants here for the compiler to optimize away :-)
memcpy(keyBuf, keyPrefix, sizeof(keyPrefix)-1);
memcpy(keyBuf+sizeof(keyPrefix)-1, PyWin_DLLVersionString, versionLen);
memcpy(keyBuf+sizeof(keyPrefix)-1+versionLen, keySuffix, sizeof(keySuffix)); // NULL comes with this one!
rc=RegOpenKey(keyBase,
keyBuf,
&newKey);
if (rc==ERROR_SUCCESS) {
RegQueryInfoKey(newKey, NULL, NULL, NULL, NULL, NULL, NULL,
&numEntries, &nameSize, &dataSize, NULL, NULL);
}
if (bWin32s && numEntries==0 && dataSize==0) {
/* must hardcode for Win32s */
numEntries = 1;
dataSize = 511;
}
if (numEntries) {
/* Loop over all subkeys. */
/* Win32s doesnt know how many subkeys, so we do
it twice */
char keyBuf[MAX_PATH+1];
int index = 0;
int off = 0;
for(index=0;;index++) {
long reqdSize = 0;
DWORD rc = RegEnumKey(newKey,
index, keyBuf, MAX_PATH+1);
if (rc) break;
rc = RegQueryValue(newKey, keyBuf, NULL, &reqdSize);
if (rc) break;
if (bWin32s && reqdSize==0) reqdSize = 512;
dataSize += reqdSize + 1; /* 1 for the ";" */
}
dataBuf = malloc(dataSize+1);
if (dataBuf==NULL)
return NULL; /* pretty serious? Raise error? */
/* Now loop over, grabbing the paths.
Subkeys before main library */
for(index=0;;index++) {
int adjust;
long reqdSize = dataSize;
DWORD rc = RegEnumKey(newKey,
index, keyBuf,MAX_PATH+1);
if (rc) break;
rc = RegQueryValue(newKey,
keyBuf, dataBuf+off, &reqdSize);
if (rc) break;
if (reqdSize>1) {
/* If Nothing, or only '\0' copied. */
adjust = strlen(dataBuf+off);
dataSize -= adjust;
off += adjust;
dataBuf[off++] = ';';
dataBuf[off] = '\0';
dataSize--;
}
}
/* Additionally, win32s doesnt work as expected, so
the specific strlen() is required for 3.1. */
rc = RegQueryValue(newKey, "", dataBuf+off, &dataSize);
if (rc==ERROR_SUCCESS) {
if (strlen(dataBuf)==0)
free(dataBuf);
else
retval = dataBuf; /* caller will free */
}
else
free(dataBuf);
}
if (newKey)
RegCloseKey(newKey);
return retval;
}
#endif /* MS_WIN32 */
static void
get_progpath(void)
{
extern char *Py_GetProgramName(void);
char *path = getenv("PATH");
char *prog = Py_GetProgramName();
#ifdef MS_WIN32
if (GetModuleFileName(NULL, progpath, MAXPATHLEN))
return;
#endif
if (prog == NULL || *prog == '\0')
prog = "python";
/* If there is no slash in the argv0 path, then we have to
* assume python is on the user's $PATH, since there's no
* other way to find a directory to start the search from. If
* $PATH isn't exported, you lose.
*/
#ifdef ALTSEP
if (strchr(prog, SEP) || strchr(prog, ALTSEP))
#else
if (strchr(prog, SEP))
#endif
strcpy(progpath, prog);
else if (path) {
while (1) {
char *delim = strchr(path, DELIM);
if (delim) {
int len = delim - path;
strncpy(progpath, path, len);
*(progpath + len) = '\0';
}
else
strcpy(progpath, path);
join(progpath, prog);
if (exists(progpath))
break;
if (!delim) {
progpath[0] = '\0';
break;
}
path = delim + 1;
}
}
else
progpath[0] = '\0';
}
static void
calculate_path(void)
{
char argv0_path[MAXPATHLEN+1];
char *buf;
int bufsz;
char *pythonhome = Py_GetPythonHome();
char *envpath = Py_GETENV("PYTHONPATH");
#ifdef MS_WIN32
char *machinepath, *userpath;
/* Are we running under Windows 3.1(1) Win32s? */
if (PyWin_IsWin32s()) {
/* Only CLASSES_ROOT is supported */
machinepath = getpythonregpath(HKEY_CLASSES_ROOT, TRUE);
userpath = NULL;
} else {
machinepath = getpythonregpath(HKEY_LOCAL_MACHINE, FALSE);
userpath = getpythonregpath(HKEY_CURRENT_USER, FALSE);
}
#endif
get_progpath();
strcpy(argv0_path, progpath);
reduce(argv0_path);
if (pythonhome == NULL || *pythonhome == '\0') {
if (search_for_prefix(argv0_path, LANDMARK))
pythonhome = prefix;
else
pythonhome = NULL;
}
else {
char *delim;
strcpy(prefix, pythonhome);
/* Extract Any Optional Trailing EXEC_PREFIX */
/* e.g. PYTHONHOME=<prefix>:<exec_prefix> */
delim = strchr(prefix, DELIM);
if (delim) {
*delim = '\0';
strcpy(exec_prefix, delim+1);
} else
strcpy(exec_prefix, EXEC_PREFIX);
}
if (envpath && *envpath == '\0')
envpath = NULL;
/* We need to construct a path from the following parts:
(1) the PYTHONPATH environment variable, if set;
(2) for Win32, the machinepath and userpath, if set;
(3) the PYTHONPATH config macro, with the leading "."
of each component replaced with pythonhome, if set;
(4) the directory containing the executable (argv0_path).
The length calculation calculates #3 first.
*/
/* Calculate size of return buffer */
if (pythonhome != NULL) {
char *p;
bufsz = 1;
for (p = PYTHONPATH; *p; p++) {
if (*p == DELIM)
bufsz++; /* number of DELIM plus one */
}
bufsz *= strlen(pythonhome);
}
else
bufsz = 0;
bufsz += strlen(PYTHONPATH) + 1;
if (envpath != NULL)
bufsz += strlen(envpath) + 1;
bufsz += strlen(argv0_path) + 1;
#ifdef MS_WIN32
if (machinepath)
bufsz += strlen(machinepath) + 1;
if (userpath)
bufsz += strlen(userpath) + 1;
#endif
module_search_path = buf = malloc(bufsz);
if (buf == NULL) {
/* We can't exit, so print a warning and limp along */
fprintf(stderr, "Can't malloc dynamic PYTHONPATH.\n");
if (envpath) {
fprintf(stderr, "Using default static $PYTHONPATH.\n");
module_search_path = envpath;
}
else {
fprintf(stderr, "Using environment $PYTHONPATH.\n");
module_search_path = PYTHONPATH;
}
return;
}
if (envpath) {
strcpy(buf, envpath);
buf = strchr(buf, '\0');
*buf++ = DELIM;
}
#ifdef MS_WIN32
if (machinepath) {
strcpy(buf, machinepath);
buf = strchr(buf, '\0');
*buf++ = DELIM;
}
if (userpath) {
strcpy(buf, userpath);
buf = strchr(buf, '\0');
*buf++ = DELIM;
}
#endif
if (pythonhome == NULL) {
strcpy(buf, PYTHONPATH);
buf = strchr(buf, '\0');
}
else {
char *p = PYTHONPATH;
char *q;
int n;
for (;;) {
q = strchr(p, DELIM);
if (q == NULL)
n = strlen(p);
else
n = q-p;
if (p[0] == '.' && is_sep(p[1])) {
strcpy(buf, pythonhome);
buf = strchr(buf, '\0');
p++;
n--;
}
strncpy(buf, p, n);
buf += n;
if (q == NULL)
break;
*buf++ = DELIM;
p = q+1;
}
}
if (argv0_path) {
*buf++ = DELIM;
strcpy(buf, argv0_path);
buf = strchr(buf, '\0');
}
*buf = '\0';
}
/* External interface */
char *
Py_GetPath(void)
{
if (!module_search_path)
calculate_path();
return module_search_path;
}
char *
Py_GetPrefix(void)
{
if (!module_search_path)
calculate_path();
return prefix;
}
char *
Py_GetExecPrefix(void)
{
if (!module_search_path)
calculate_path();
return exec_prefix;
}
char *
Py_GetProgramFullPath(void)
{
if (!module_search_path)
calculate_path();
return progpath;
}