symbian-qemu-0.9.1-12/python-2.6.1/PC/os2emx/getpathp.c
changeset 1 2fb8b9db1c86
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/symbian-qemu-0.9.1-12/python-2.6.1/PC/os2emx/getpathp.c	Fri Jul 31 15:01:17 2009 +0100
@@ -0,0 +1,418 @@
+
+/* Return the initial module search path. */
+/* This version used by OS/2+EMX */
+
+/* ----------------------------------------------------------------
+   PATH RULES FOR OS/2+EMX:
+   This describes how sys.path is formed on OS/2+EMX.  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, its entries are added next.
+
+   * 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\\os.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, and have not had a PYTHONPATH
+     specified (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.
+
+  * 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"
+
+#ifndef PYOS_OS2
+#error This file only compilable on OS/2
+#endif
+
+#define INCL_DOS
+#include <os2.h>
+
+#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.
+ *
+ * Py_GetPath() tries to return a sensible Python module search path.
+ *
+ * The approach is an adaptation for Windows of the strategy used in
+ * ../Modules/getpath.c; it uses the Windows Registry as one of its
+ * information sources.
+ */
+
+#ifndef LANDMARK
+#if defined(PYCC_GCC)
+#define LANDMARK "lib/os.py"
+#else
+#define LANDMARK "lib\\os.py"
+#endif
+#endif
+
+static char 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
+}
+
+/* assumes 'dir' null terminated in bounds.
+ * Never writes beyond existing terminator.
+ */
+static void
+reduce(char *dir)
+{
+	size_t 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;
+}
+
+/* Is module  (check for .pyc/.pyo too)
+ * Assumes 'filename' MAXPATHLEN+1 bytes long - 
+ * may extend 'filename' by one character.
+ */
+static int
+ismodule(char *filename)
+{
+	if (exists(filename))
+		return 1;
+
+	/* Check for the compiled version of prefix. */
+	if (strlen(filename) < MAXPATHLEN) {
+		strcat(filename, Py_OptimizeFlag ? "o" : "c");
+		if (exists(filename))
+			return 1;
+	}
+	return 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)
+{
+	size_t 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';
+}
+
+/* gotlandmark only called by search_for_prefix, which ensures
+ * 'prefix' is null terminated in bounds.  join() ensures
+ * 'landmark' can not overflow prefix if too long.
+ */
+static int
+gotlandmark(char *landmark)
+{
+	int n, ok;
+
+	n = strlen(prefix);
+	join(prefix, landmark);
+	ok = ismodule(prefix);
+	prefix[n] = '\0';
+	return ok;
+}
+
+/* assumes argv0_path is MAXPATHLEN+1 bytes long, already \0 term'd. 
+ * assumption provided by only caller, calculate_path()
+ */
+static int
+search_for_prefix(char *argv0_path, char *landmark)
+{
+	/* Search from argv0_path, until landmark is found */
+	strcpy(prefix, argv0_path);
+	do {
+		if (gotlandmark(landmark))
+			return 1;
+		reduce(prefix);
+	} while (prefix[0]);
+	return 0;
+}
+
+
+static void
+get_progpath(void)
+{
+	extern char *Py_GetProgramName(void);
+	char *path = getenv("PATH");
+	char *prog = Py_GetProgramName();
+
+	PPIB pib;
+	if ((DosGetInfoBlocks(NULL, &pib) == 0) &&
+	    (DosQueryModuleName(pib->pib_hmte, sizeof(progpath), progpath) == 0))
+		return;
+
+	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
+		strncpy(progpath, prog, MAXPATHLEN);
+	else if (path) {
+		while (1) {
+			char *delim = strchr(path, DELIM);
+
+			if (delim) {
+				size_t len = delim - path;
+				/* ensure we can't overwrite buffer */
+#if !defined(PYCC_GCC)
+				len = min(MAXPATHLEN,len);
+#else
+				len = MAXPATHLEN < len ? MAXPATHLEN : len;
+#endif
+				strncpy(progpath, path, len);
+				*(progpath + len) = '\0';
+			}
+			else
+				strncpy(progpath, path, MAXPATHLEN);
+
+			/* join() is safe for MAXPATHLEN+1 size buffer */
+			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;
+	size_t bufsz;
+	char *pythonhome = Py_GetPythonHome();
+	char *envpath = getenv("PYTHONPATH");
+	char zip_path[MAXPATHLEN+1];
+	size_t len;
+
+	get_progpath();
+	/* progpath guaranteed \0 terminated in MAXPATH+1 bytes. */
+	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
+		strncpy(prefix, pythonhome, MAXPATHLEN);
+
+	if (envpath && *envpath == '\0')
+		envpath = NULL;
+
+	/* Calculate zip archive path */
+	strncpy(zip_path, progpath, MAXPATHLEN);
+	zip_path[MAXPATHLEN] = '\0';
+	len = strlen(zip_path);
+	if (len > 4) {
+		zip_path[len-3] = 'z';  /* change ending to "zip" */
+		zip_path[len-2] = 'i';
+		zip_path[len-1] = 'p';
+	}
+	else {
+		zip_path[0] = 0;
+	}
+
+	/* We need to construct a path from the following parts.
+	 * (1) the PYTHONPATH environment variable, if set;
+	 * (2) the zip archive file path;
+	 * (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;
+	bufsz += strlen(argv0_path) + 1;
+	bufsz += strlen(zip_path) + 1;
+	if (envpath != NULL)
+		bufsz += strlen(envpath) + 1;
+
+	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 environment $PYTHONPATH.\n");
+			module_search_path = envpath;
+		}
+		else {
+			fprintf(stderr, "Using default static path.\n");
+			module_search_path = PYTHONPATH;
+		}
+		return;
+	}
+
+	if (envpath) {
+		strcpy(buf, envpath);
+		buf = strchr(buf, '\0');
+		*buf++ = DELIM;
+	}
+	if (zip_path[0]) {
+		strcpy(buf, zip_path);
+		buf = strchr(buf, '\0');
+		*buf++ = DELIM;
+	}
+
+	if (pythonhome == NULL) {
+		strcpy(buf, PYTHONPATH);
+		buf = strchr(buf, '\0');
+	}
+	else {
+		char *p = PYTHONPATH;
+		char *q;
+		size_t 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)
+{
+	return Py_GetPrefix();
+}
+
+char *
+Py_GetProgramFullPath(void)
+{
+	if (!module_search_path)
+		calculate_path();
+	return progpath;
+}