]> granicus.if.org Git - python/commitdiff
Revamped path access again, by Mark Hammond, to be more robust in the
authorGuido van Rossum <guido@python.org>
Thu, 30 Mar 2000 19:45:39 +0000 (19:45 +0000)
committerGuido van Rossum <guido@python.org>
Thu, 30 Mar 2000 19:45:39 +0000 (19:45 +0000)
light of three different situations: (1) running from build; (2)
running from installed; (3) running without being able to find an
installation (e.g. as a COM object).  The system paths in the
repository are only used for (3); the path deduced from the
installation location are used otherwise.  PYTHONHOME overrides in all
cases.

Read the comments for more details.

PC/getpathp.c

index 7c4d1218294025eec0e7a451bcf11f7f437a7c26..2123b2a76c6febe3c763c1de5048d5c137c970d2 100644 (file)
@@ -32,12 +32,64 @@ PERFORMANCE OF THIS SOFTWARE.
 /* Return the initial module search path. */
 /* Used by DOS, OS/2, Windows 3.1, Windows 95/98, Windows NT. */
 
+/* ----------------------------------------------------------------
+   PATH RULES FOR WINDOWS:
+   This describes how sys.path is formed on Windows.  It describes the 
+   functionality, not the implementation (ie, the order in which these 
+   are actually fetched is different)
+
+   * Python always adds an empty entry at the start, which corresponds
+     to the current directory.
+
+   * If the PYTHONPATH env. var. exists, it's entries are added next.
+
+   * We look in the registry for "application paths" - that is, sub-keys
+     under the main PythonPath registry key.  These are added next (the
+     order of sub-key processing is undefined).
+     HKEY_CURRENT_USER is searched and added first.
+     HKEY_LOCAL_MACHINE is searched and added next.
+     (Note that all known installers only use HKLM, so HKCU is typically
+     empty)
+
+   * We attempt to locate the "Python Home" - if the PYTHONHOME env var
+     is set, we believe it.  Otherwise, we use the path of our host .EXE's
+     to try and locate our "landmark" (lib\\string.py) and deduce our home.
+     - If we DO have a Python Home: The relevant sub-directories (Lib, 
+       plat-win, lib-tk, etc) are based on the Python Home
+     - If we DO NOT have a Python Home, the core Python Path is
+       loaded from the registry.  This is the main PythonPath key, 
+       and both HKLM and HKCU are combined to form the path)
+
+   * Iff - we can not locate the Python Home, have not had a PYTHONPATH
+     specified, and can't locate any Registry entries (ie, we have _nothing_
+     we can assume is a good path), a default path with relative entries is 
+     used (eg. .\Lib;.\plat-win, etc)
+
+
+  The end result of all this is:
+  * When running python.exe, or any other .exe in the main Python directory
+    (either an installed version, or directly from the PCbuild directory),
+    the core path is deduced, and the core paths in the registry are
+    ignored.  Other "application paths" in the registry are always read.
+
+  * When Python is hosted in another exe (different directory, embedded via 
+    COM, etc), the Python Home will not be deduced, so the core path from
+    the registry is used.  Other "application paths "in the registry are 
+    always read.
+
+  * If Python can't find its home and there is no registry (eg, frozen
+    exe, some very strange installation setup) you get a path with
+    some default, but relative, paths.
+
+   ---------------------------------------------------------------- */
+
+
 #include "Python.h"
 #include "osdefs.h"
 
 #ifdef MS_WIN32
 #include <windows.h>
-extern BOOL PyWin_IsWin32s();
+#include <tchar.h>
 #endif
 
 #include <sys/types.h>
@@ -168,107 +220,146 @@ search_for_prefix(argv0_path, landmark)
 
 #ifdef MS_WIN32
 
-#ifndef BUILD_LANDMARK
-#define BUILD_LANDMARK "PC\\getpathp.c"
-#endif
-
-#include "malloc.h" // for alloca - see comments below!
-extern const char *PyWin_DLLVersionString; // a string loaded from the DLL at startup.
+/* a string loaded from the DLL at startup.*/
+extern const char *PyWin_DLLVersionString;
 
 
 /* Load a PYTHONPATH value from the registry.
    Load from either HKEY_LOCAL_MACHINE or HKEY_CURRENT_USER.
 
+   Works in both Unicode and 8bit environments.  Only uses the
+   Ex family of functions so it also works with Windows CE.
+
    Returns NULL, or a pointer that should be freed.
 */
 
 static char *
-getpythonregpath(HKEY keyBase)
+getpythonregpath(HKEY keyBase, int skipcore)
 {
        HKEY newKey = 0;
-       DWORD nameSize = 0;
        DWORD dataSize = 0;
-       DWORD numEntries = 0;
+       DWORD numKeys = 0;
        LONG rc;
        char *retval = NULL;
-       char *dataBuf;
-       const char keyPrefix[] = "Software\\Python\\PythonCore\\";
-       const char keySuffix[] = "\\PythonPath";
+       TCHAR *dataBuf = NULL;
+       static const TCHAR keyPrefix[] = _T("Software\\Python\\PythonCore\\");
+       static const TCHAR keySuffix[] = _T("\\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 (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;
-                       dataSize += reqdSize + 1; /* 1 for the ";" */
+       DWORD index;
+       TCHAR *keyBuf = NULL;
+       TCHAR *keyBufPtr;
+       TCHAR **ppPaths = NULL;
+
+       /* Tried to use sysget("winver") but here is too early :-( */
+       versionLen = _tcslen(PyWin_DLLVersionString);
+       /* Space for all the chars, plus one \0 */
+       keyBuf = keyBufPtr = malloc(sizeof(keyPrefix) + 
+                                   sizeof(TCHAR)*(versionLen-1) + 
+                                   sizeof(keySuffix));
+       if (keyBuf==NULL) goto done;
+
+       memcpy(keyBufPtr, keyPrefix, sizeof(keyPrefix)-sizeof(TCHAR));
+       keyBufPtr += sizeof(keyPrefix)/sizeof(TCHAR) - 1;
+       memcpy(keyBufPtr, PyWin_DLLVersionString, versionLen * sizeof(TCHAR));
+       keyBufPtr += versionLen;
+       /* NULL comes with this one! */
+       memcpy(keyBufPtr, keySuffix, sizeof(keySuffix));
+       /* Open the root Python key */
+       rc=RegOpenKeyEx(keyBase,
+                       keyBuf, /* subkey */
+                       0, /* reserved */
+                       KEY_READ,
+                       &newKey);
+       if (rc!=ERROR_SUCCESS) goto done;
+       /* Find out how big our core buffer is, and how many subkeys we have */
+       rc = RegQueryInfoKey(newKey, NULL, NULL, NULL, &numKeys, NULL, NULL, 
+                       NULL, NULL, &dataSize, NULL, NULL);
+       if (rc!=ERROR_SUCCESS) goto done;
+       if (skipcore) dataSize = 0; /* Only count core ones if we want them! */
+       /* Allocate a temp array of char buffers, so we only need to loop 
+          reading the registry once
+       */
+       ppPaths = malloc( sizeof(TCHAR *) * numKeys );
+       if (ppPaths==NULL) goto done;
+       memset(ppPaths, 0, sizeof(TCHAR *) * numKeys);
+       /* Loop over all subkeys, allocating a temp sub-buffer. */
+       for(index=0;index<numKeys;index++) {
+               TCHAR keyBuf[MAX_PATH+1];
+               HKEY subKey = 0;
+               DWORD reqdSize = MAX_PATH+1;
+               /* Get the sub-key name */
+               DWORD rc = RegEnumKeyEx(newKey, index, keyBuf, &reqdSize,
+                                       NULL, NULL, NULL, NULL );
+               if (rc!=ERROR_SUCCESS) goto done;
+               /* Open the sub-key */
+               rc=RegOpenKeyEx(newKey,
+                                               keyBuf, /* subkey */
+                                               0, /* reserved */
+                                               KEY_READ,
+                                               &subKey);
+               if (rc!=ERROR_SUCCESS) goto done;
+               /* Find the value of the buffer size, malloc, then read it */
+               RegQueryValueEx(subKey, NULL, 0, NULL, NULL, &reqdSize);
+               if (reqdSize) {
+                       ppPaths[index] = malloc(reqdSize);
+                       if (ppPaths[index]) {
+                               RegQueryValueEx(subKey, NULL, 0, NULL, (LPBYTE)ppPaths[index], &reqdSize);
+                               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';
+               RegCloseKey(subKey);
+       }
+       dataBuf = malloc((dataSize+1) * sizeof(TCHAR));
+       if (dataBuf) {
+               TCHAR *szCur = dataBuf;
+               DWORD reqdSize = dataSize;
+               /* Copy our collected strings */
+               for (index=0;index<numKeys;index++) {
+                       int len;
+                       if (index > 0) {
+                               *(szCur++) = _T(';');
                                dataSize--;
                        }
+                       len = _tcslen(ppPaths[index]);
+                       _tcsncpy(szCur, ppPaths[index], len);
+                       szCur += len;
+                       dataSize -= len;
                }
-               /* 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 */
+               if (skipcore)
+                       *szCur = '\0';
+               else {
+                       *(szCur++) = _T(';');
+                       dataSize--;
+                       /* Now append the core path entries - this will include the NULL */
+                       rc = RegQueryValueEx(newKey, NULL, 0, NULL, (LPBYTE)szCur, &dataSize);
                }
-               else
-                       free(dataBuf);
+               /* And set the result - caller must free 
+                  If MBCS, it is fine as is.  If Unicode, allocate new
+                  buffer and convert.
+               */
+#ifdef UNICODE
+               retval = (char *)malloc(reqdSize+1);
+               if (retval)
+                       WideCharToMultiByte(CP_ACP, 0, 
+                                       dataBuf, -1, /* source */ 
+                                       retval, dataSize+1, /* dest */
+                                       NULL, NULL);
+               free(dataBuf);
+#else
+               retval = dataBuf;
+#endif
+       }
+done:
+       /* Loop freeing my temp buffers */
+       if (ppPaths) {
+               for(index=0;index<numKeys;index++)
+                       if (ppPaths[index]) free(ppPaths[index]);
+               free(ppPaths);
        }
-
        if (newKey)
                RegCloseKey(newKey);
+       if (keyBuf)
+               free(keyBuf);
        return retval;
 }
 #endif /* MS_WIN32 */
@@ -281,8 +372,16 @@ get_progpath()
        char *prog = Py_GetProgramName();
 
 #ifdef MS_WIN32
+#ifdef UNICODE
+       WCHAR wprogpath[MAXPATHLEN+1];
+       if (GetModuleFileName(NULL, wprogpath, MAXPATHLEN)) {
+               WideCharToMultiByte(CP_ACP, 0, wprogpath, -1, progpath, MAXPATHLEN+1, NULL, NULL);
+               return;
+       }
+#else
        if (GetModuleFileName(NULL, progpath, MAXPATHLEN))
                return;
+#endif
 #endif
        if (prog == NULL || *prog == '\0')
                prog = "python";
@@ -335,7 +434,7 @@ calculate_path()
        char *envpath = getenv("PYTHONPATH");
 
 #ifdef MS_WIN32
-       int skiphome = 0;
+       int skiphome, skipdefault;
        char *machinepath = NULL;
        char *userpath = NULL;
 #endif
@@ -357,10 +456,13 @@ calculate_path()
 
 
 #ifdef MS_WIN32
-       if (!gotlandmark(BUILD_LANDMARK)) {
-               machinepath = getpythonregpath(HKEY_LOCAL_MACHINE);
-               userpath = getpythonregpath(HKEY_CURRENT_USER);
-       }
+       skiphome = pythonhome==NULL ? 0 : 1;
+       machinepath = getpythonregpath(HKEY_LOCAL_MACHINE, skiphome);
+       userpath = getpythonregpath(HKEY_CURRENT_USER, skiphome);
+       /* We only use the default relative PYTHONPATH if we havent
+          anything better to use! */
+       skipdefault = envpath!=NULL || pythonhome!=NULL || \
+                     machinepath!=NULL || userpath!=NULL;
 #endif
 
        /* We need to construct a path from the following parts.
@@ -430,24 +532,25 @@ calculate_path()
                buf = strchr(buf, '\0');
                *buf++ = DELIM;
                free(userpath);
-               skiphome = 1;
        }
        if (machinepath) {
                strcpy(buf, machinepath);
                buf = strchr(buf, '\0');
                *buf++ = DELIM;
                free(machinepath);
-               skiphome = 1;
        }
-       if (skiphome) {
-               *buf = 0;
-               return;
+       if (pythonhome == NULL) {
+               if (!skipdefault) {
+                       strcpy(buf, PYTHONPATH);
+                       buf = strchr(buf, '\0');
+               }
        }
-#endif
+#else
        if (pythonhome == NULL) {
                strcpy(buf, PYTHONPATH);
                buf = strchr(buf, '\0');
        }
+#endif /* MS_WIN32 */
        else {
                char *p = PYTHONPATH;
                char *q;
@@ -512,4 +615,3 @@ Py_GetProgramFullPath()
                calculate_path();
        return progpath;
 }
-