gcc_darwin_arm64.c

     1  // Copyright 2014 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  #include <limits.h>
     6  #include <pthread.h>
     7  #include <signal.h>
     8  #include <string.h> /* for strerror */
     9  #include <sys/param.h>
    10  #include <unistd.h>
    11  #include <stdlib.h>
    12  
    13  #include "libcgo.h"
    14  #include "libcgo_unix.h"
    15  
    16  #include <TargetConditionals.h>
    17  
    18  #if TARGET_OS_IPHONE
    19  #include <CoreFoundation/CFBundle.h>
    20  #include <CoreFoundation/CFString.h>
    21  #endif
    22  
    23  static void *threadentry(void*);
    24  static void (*setg_gcc)(void*);
    25  
    26  void
    27  _cgo_sys_thread_start(ThreadStart *ts)
    28  {
    29  	pthread_attr_t attr;
    30  	sigset_t ign, oset;
    31  	pthread_t p;
    32  	size_t size;
    33  	int err;
    34  
    35  	//fprintf(stderr, "runtime/cgo: _cgo_sys_thread_start: fn=%p, g=%p\n", ts->fn, ts->g); // debug
    36  	sigfillset(&ign);
    37  	pthread_sigmask(SIG_SETMASK, &ign, &oset);
    38  
    39  	size = pthread_get_stacksize_np(pthread_self());
    40  	pthread_attr_init(&attr);
    41  	pthread_attr_setstacksize(&attr, size);
    42  	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
    43  	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
    44  	ts->g->stackhi = size;
    45  	err = _cgo_try_pthread_create(&p, &attr, threadentry, ts);
    46  
    47  	pthread_sigmask(SIG_SETMASK, &oset, nil);
    48  
    49  	if (err != 0) {
    50  		fprintf(stderr, "runtime/cgo: pthread_create failed: %s\n", strerror(err));
    51  		abort();
    52  	}
    53  }
    54  
    55  extern void crosscall1(void (*fn)(void), void (*setg_gcc)(void*), void *g);
    56  static void*
    57  threadentry(void *v)
    58  {
    59  	ThreadStart ts;
    60  
    61  	ts = *(ThreadStart*)v;
    62  	free(v);
    63  
    64  #if TARGET_OS_IPHONE
    65  	darwin_arm_init_thread_exception_port();
    66  #endif
    67  
    68  	crosscall1(ts.fn, setg_gcc, (void*)ts.g);
    69  	return nil;
    70  }
    71  
    72  #if TARGET_OS_IPHONE
    73  
    74  // init_working_dir sets the current working directory to the app root.
    75  // By default ios/arm64 processes start in "/".
    76  static void
    77  init_working_dir()
    78  {
    79  	CFBundleRef bundle = CFBundleGetMainBundle();
    80  	if (bundle == NULL) {
    81  		fprintf(stderr, "runtime/cgo: no main bundle\n");
    82  		return;
    83  	}
    84  	CFURLRef url_ref = CFBundleCopyResourceURL(bundle, CFSTR("Info"), CFSTR("plist"), NULL);
    85  	if (url_ref == NULL) {
    86  		// No Info.plist found. It can happen on Corellium virtual devices.
    87  		return;
    88  	}
    89  	CFStringRef url_str_ref = CFURLGetString(url_ref);
    90  	char buf[MAXPATHLEN];
    91  	Boolean res = CFStringGetCString(url_str_ref, buf, sizeof(buf), kCFStringEncodingUTF8);
    92  	CFRelease(url_ref);
    93  	if (!res) {
    94  		fprintf(stderr, "runtime/cgo: cannot get URL string\n");
    95  		return;
    96  	}
    97  
    98  	// url is of the form "file:///path/to/Info.plist".
    99  	// strip it down to the working directory "/path/to".
   100  	int url_len = strlen(buf);
   101  	if (url_len < sizeof("file://")+sizeof("/Info.plist")) {
   102  		fprintf(stderr, "runtime/cgo: bad URL: %s\n", buf);
   103  		return;
   104  	}
   105  	buf[url_len-sizeof("/Info.plist")+1] = 0;
   106  	char *dir = &buf[0] + sizeof("file://")-1;
   107  
   108  	if (chdir(dir) != 0) {
   109  		fprintf(stderr, "runtime/cgo: chdir(%s) failed\n", dir);
   110  	}
   111  
   112  	// The test harness in go_ios_exec passes the relative working directory
   113  	// in the GoExecWrapperWorkingDirectory property of the app bundle.
   114  	CFStringRef wd_ref = CFBundleGetValueForInfoDictionaryKey(bundle, CFSTR("GoExecWrapperWorkingDirectory"));
   115  	if (wd_ref != NULL) {
   116  		if (!CFStringGetCString(wd_ref, buf, sizeof(buf), kCFStringEncodingUTF8)) {
   117  			fprintf(stderr, "runtime/cgo: cannot get GoExecWrapperWorkingDirectory string\n");
   118  			return;
   119  		}
   120  		if (chdir(buf) != 0) {
   121  			fprintf(stderr, "runtime/cgo: chdir(%s) failed\n", buf);
   122  		}
   123  	}
   124  }
   125  
   126  #endif // TARGET_OS_IPHONE
   127  
   128  void
   129  x_cgo_init(G *g, void (*setg)(void*))
   130  {
   131  	//fprintf(stderr, "x_cgo_init = %p\n", &x_cgo_init); // aid debugging in presence of ASLR
   132  	setg_gcc = setg;
   133  	_cgo_set_stacklo(g, NULL);
   134  
   135  #if TARGET_OS_IPHONE
   136  	darwin_arm_init_mach_exception_handler();
   137  	darwin_arm_init_thread_exception_port();
   138  	init_working_dir();
   139  #endif
   140  }
   141
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