--- /dev/null
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include <limits.h>
+#include <pthread.h>
+#include <signal.h>
+#include <string.h> /* for strerror */
+#include <sys/param.h>
+#include <unistd.h>
+#include <stdlib.h>
+
+#include "libcgo.h"
+
+#include <CoreFoundation/CFBundle.h>
+#include <CoreFoundation/CFString.h>
+
+#define magic (0xc476c475c47957UL)
+
+// inittls allocates a thread-local storage slot for g.
+//
+// It finds the first available slot using pthread_key_create and uses
+// it as the offset value for runtime.tlsg.
+static void
+inittls(void **tlsg, void **tlsbase)
+{
+ pthread_key_t k;
+ int i, err;
+
+ err = pthread_key_create(&k, nil);
+ if(err != 0) {
+ fprintf(stderr, "runtime/cgo: pthread_key_create failed: %d\n", err);
+ abort();
+ }
+ //fprintf(stderr, "runtime/cgo: k = %d, tlsbase = %p\n", (int)k, tlsbase); // debug
+ pthread_setspecific(k, (void*)magic);
+ // The first key should be at 257.
+ for (i=0; i<PTHREAD_KEYS_MAX; i++) {
+ if (*(tlsbase+i) == (void*)magic) {
+ *tlsg = (void*)(i*sizeof(void *));
+ pthread_setspecific(k, 0);
+ return;
+ }
+ }
+ fprintf(stderr, "runtime/cgo: could not find pthread key.\n");
+ abort();
+}
+
+static void *threadentry(void*);
+void (*setg_gcc)(void*);
+
+void
+_cgo_sys_thread_start(ThreadStart *ts)
+{
+ pthread_attr_t attr;
+ sigset_t ign, oset;
+ pthread_t p;
+ size_t size;
+ int err;
+
+ //fprintf(stderr, "runtime/cgo: _cgo_sys_thread_start: fn=%p, g=%p\n", ts->fn, ts->g); // debug
+ sigfillset(&ign);
+ pthread_sigmask(SIG_SETMASK, &ign, &oset);
+
+ pthread_attr_init(&attr);
+ size = 0;
+ pthread_attr_getstacksize(&attr, &size);
+ // Leave stacklo=0 and set stackhi=size; mstack will do the rest.
+ ts->g->stackhi = size;
+ err = pthread_create(&p, &attr, threadentry, ts);
+
+ pthread_sigmask(SIG_SETMASK, &oset, nil);
+
+ if (err != 0) {
+ fprintf(stderr, "runtime/cgo: pthread_create failed: %s\n", strerror(err));
+ abort();
+ }
+}
+
+extern void crosscall1(void (*fn)(void), void (*setg_gcc)(void*), void *g);
+static void*
+threadentry(void *v)
+{
+ ThreadStart ts;
+
+ ts = *(ThreadStart*)v;
+ free(v);
+
+ crosscall1(ts.fn, setg_gcc, (void*)ts.g);
+ return nil;
+}
+
+// init_working_dir sets the current working directory to the app root.
+// By default darwin/arm processes start in "/".
+static void
+init_working_dir()
+{
+ CFBundleRef bundle = CFBundleGetMainBundle();
+ if (bundle == NULL) {
+ fprintf(stderr, "runtime/cgo: no main bundle\n");
+ return;
+ }
+ CFURLRef url_ref = CFBundleCopyResourceURL(bundle, CFSTR("Info"), CFSTR("plist"), NULL);
+ if (url_ref == NULL) {
+ fprintf(stderr, "runtime/cgo: no Info.plist URL\n");
+ return;
+ }
+ CFStringRef url_str_ref = CFURLGetString(url_ref);
+ char url[MAXPATHLEN];
+ if (!CFStringGetCString(url_str_ref, url, sizeof(url), kCFStringEncodingUTF8)) {
+ fprintf(stderr, "runtime/cgo: cannot get URL string\n");
+ return;
+ }
+
+ // url is of the form "file:///path/to/Info.plist".
+ // strip it down to the working directory "/path/to".
+ int url_len = strlen(url);
+ if (url_len < sizeof("file://")+sizeof("/Info.plist")) {
+ fprintf(stderr, "runtime/cgo: bad URL: %s\n", url);
+ return;
+ }
+ url[url_len-sizeof("/Info.plist")+1] = 0;
+ char *dir = &url[0] + sizeof("file://")-1;
+
+ if (chdir(dir) != 0) {
+ fprintf(stderr, "runtime/cgo: chdir(%s) failed\n", dir);
+ }
+
+ // No-op to set a breakpoint on, immediately after the real chdir.
+ // Gives the test harness in go_darwin_arm_exec (which uses lldb) a
+ // chance to move the working directory.
+ getwd(dir);
+}
+
+void
+x_cgo_init(G *g, void (*setg)(void*), void **tlsg, void **tlsbase)
+{
+ pthread_attr_t attr;
+ size_t size;
+
+ //fprintf(stderr, "x_cgo_init = %p\n", &x_cgo_init); // aid debugging in presence of ASLR
+ setg_gcc = setg;
+ pthread_attr_init(&attr);
+ pthread_attr_getstacksize(&attr, &size);
+ g->stacklo = (uintptr)&attr - size + 4096;
+ pthread_attr_destroy(&attr);
+
+ // yes, tlsbase from mrs might not be correctly aligned.
+ inittls(tlsg, (void**)((uintptr)tlsbase & ~7));
+
+ init_working_dir();
+}