1 files changed, 167 insertions, 6 deletions

diff --git a/Mac/Tools/pythonw.c b/Mac/Tools/pythonw.c
index e70a76f846f..30c82ac4760 100644
--- a/Mac/Tools/pythonw.c
+++ b/Mac/Tools/pythonw.c
@@ -3,15 +3,176 @@
  * application bundle inside the Python framework. This is needed to run
  * GUI code: some GUI API's don't work unless the program is inside an
  * application bundle.
+ *
+ * This program uses posix_spawn rather than plain execv because we need
+ * slightly more control over how the "real" interpreter is executed.
+ *
+ * On OSX 10.4 (and earlier) this falls back to using exec because the
+ * posix_spawnv functions aren't available there.
  */
+
+#pragma weak_import posix_spawnattr_init
+#pragma weak_import posix_spawnattr_setbinpref_np
+#pragma weak_import posix_spawnattr_setflags
+#pragma weak_import posix_spawn
+
+#include <Python.h>
 #include <unistd.h>
+#ifdef HAVE_SPAWN_H
+#include <spawn.h>
+#endif
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
 #include <err.h>
+#include <dlfcn.h>
+#include <stdlib.h>
+#include <Python.h>
+
+
+extern char** environ;
+
+/*
+ * Locate the python framework by looking for the
+ * library that contains Py_Initialize.
+ *
+ * In a regular framework the structure is:
+ *
+ *    Python.framework/Versions/2.7
+ *              /Python
+ *              /Resources/Python.app/Contents/MacOS/Python
+ *
+ * In a virtualenv style structure the expected
+ * structure is:
+ *
+ *    ROOT
+ *       /bin/pythonw
+ *       /.Python   <- the dylib
+ *       /.Resources/Python.app/Contents/MacOS/Python
+ *
+ * NOTE: virtualenv's are not an officially supported
+ * feature, support for that structure is provided as
+ * a convenience.
+ */
+static char* get_python_path(void)
+{
+    size_t len;
+    Dl_info info;
+    char* end;
+    char* g_path;
+
+    if (dladdr(Py_Initialize, &info) == 0) {
+        return NULL;
+    }
+
+    len = strlen(info.dli_fname);
+
+    g_path = malloc(len+60);
+    if (g_path == NULL) {
+        return NULL;
+    }
+
+    strcpy(g_path, info.dli_fname);
+    end = g_path + len - 1;
+    while (end != g_path && *end != '/') {
+        end --;
+    }
+    end++;
+    if (*end == '.') {
+        end++;
+    }
+    strcpy(end, "Resources/Python.app/Contents/MacOS/" PYTHONFRAMEWORK);
+
+    return g_path;
+}
+
+#ifdef HAVE_SPAWN_H
+static void
+setup_spawnattr(posix_spawnattr_t* spawnattr)
+{
+    size_t ocount;
+    size_t count;
+    cpu_type_t cpu_types[1];
+    short flags = 0;
+#ifdef __LP64__
+    int   ch;
+#endif
+
+    if ((errno = posix_spawnattr_init(spawnattr)) != 0) {
+        err(2, "posix_spawnattr_int");
+        /* NOTREACHTED */
+    }
+
+    count = 1;
+
+    /* Run the real python executable using the same architecture as this
+     * executable, this allows users to control the architecture using
+     * "arch -ppc python"
+     */
+
+#if defined(__ppc64__)
+    cpu_types[0] = CPU_TYPE_POWERPC64;
+
+#elif defined(__x86_64__)
+    cpu_types[0] = CPU_TYPE_X86_64;
+
+#elif defined(__ppc__)
+    cpu_types[0] = CPU_TYPE_POWERPC;
+#elif defined(__i386__)
+    cpu_types[0] = CPU_TYPE_X86;
+#else
+#       error "Unknown CPU"
+#endif
+
+    if (posix_spawnattr_setbinpref_np(spawnattr, count,
+                            cpu_types, &ocount) == -1) {
+        err(1, "posix_spawnattr_setbinpref");
+        /* NOTREACHTED */
+    }
+    if (count != ocount) {
+        fprintf(stderr, "posix_spawnattr_setbinpref failed to copy\n");
+        exit(1);
+        /* NOTREACHTED */
+    }
+
+
+    /*
+     * Set flag that causes posix_spawn to behave like execv
+     */
+    flags |= POSIX_SPAWN_SETEXEC;
+    if ((errno = posix_spawnattr_setflags(spawnattr, flags)) != 0) {
+        err(1, "posix_spawnattr_setflags");
+        /* NOTREACHTED */
+    }
+}
+#endif
+
+int
+main(int argc, char **argv) {
+    char* exec_path = get_python_path();
+
+    /*
+     * Let argv[0] refer to the new interpreter. This is needed to
+     * get the effect we want on OSX 10.5 or earlier. That is, without
+     * changing argv[0] the real interpreter won't have access to
+     * the Window Server.
+     */
+    argv[0] = exec_path;
 
-static char Python[] = PYTHONWEXECUTABLE;
+#ifdef HAVE_SPAWN_H
+    /* We're weak-linking to posix-spawnv to ensure that
+     * an executable build on 10.5 can work on 10.4.
+     */
+    if (posix_spawn != NULL) {
+        posix_spawnattr_t spawnattr = NULL;
 
-int main(int argc, char **argv) {
-	argv[0] = Python;
-	execv(Python, argv);
-	err(1, "execv: %s", Python);
-	/* NOTREACHED */
+        setup_spawnattr(&spawnattr);
+        posix_spawn(NULL, exec_path, NULL,
+            &spawnattr, argv, environ);
+        err(1, "posix_spawn: %s", exec_path);
+    }
+#endif
+    execve(exec_path, argv, environ);
+    err(1, "execve: %s", argv[0]);
+    /* NOTREACHED */
 }