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  	pthread_attr_init(&attr);
    40  	size = 0;
    41  	pthread_attr_getstacksize(&attr, &size);
    42  	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
    43  	ts->g->stackhi = size;
    44  	err = _cgo_try_pthread_create(&p, &attr, threadentry, ts);
    45  
    46  	pthread_sigmask(SIG_SETMASK, &oset, nil);
    47  
    48  	if (err != 0) {
    49  		fprintf(stderr, "runtime/cgo: pthread_create failed: %s\n", strerror(err));
    50  		abort();
    51  	}
    52  }
    53  
    54  extern void crosscall1(void (*fn)(void), void (*setg_gcc)(void*), void *g);
    55  static void*
    56  threadentry(void *v)
    57  {
    58  	ThreadStart ts;
    59  
    60  	ts = *(ThreadStart*)v;
    61  	free(v);
    62  
    63  #if TARGET_OS_IPHONE
    64  	darwin_arm_init_thread_exception_port();
    65  #endif
    66  
    67  	crosscall1(ts.fn, setg_gcc, (void*)ts.g);
    68  	return nil;
    69  }
    70  
    71  #if TARGET_OS_IPHONE
    72  
    73  // init_working_dir sets the current working directory to the app root.
    74  // By default ios/arm64 processes start in "/".
    75  static void
    76  init_working_dir()
    77  {
    78  	CFBundleRef bundle = CFBundleGetMainBundle();
    79  	if (bundle == NULL) {
    80  		fprintf(stderr, "runtime/cgo: no main bundle\n");
    81  		return;
    82  	}
    83  	CFURLRef url_ref = CFBundleCopyResourceURL(bundle, CFSTR("Info"), CFSTR("plist"), NULL);
    84  	if (url_ref == NULL) {
    85  		// No Info.plist found. It can happen on Corellium virtual devices.
    86  		return;
    87  	}
    88  	CFStringRef url_str_ref = CFURLGetString(url_ref);
    89  	char buf[MAXPATHLEN];
    90  	Boolean res = CFStringGetCString(url_str_ref, buf, sizeof(buf), kCFStringEncodingUTF8);
    91  	CFRelease(url_ref);
    92  	if (!res) {
    93  		fprintf(stderr, "runtime/cgo: cannot get URL string\n");
    94  		return;
    95  	}
    96  
    97  	// url is of the form "file:///path/to/Info.plist".
    98  	// strip it down to the working directory "/path/to".
    99  	int url_len = strlen(buf);
   100  	if (url_len < sizeof("file://")+sizeof("/Info.plist")) {
   101  		fprintf(stderr, "runtime/cgo: bad URL: %s\n", buf);
   102  		return;
   103  	}
   104  	buf[url_len-sizeof("/Info.plist")+1] = 0;
   105  	char *dir = &buf[0] + sizeof("file://")-1;
   106  
   107  	if (chdir(dir) != 0) {
   108  		fprintf(stderr, "runtime/cgo: chdir(%s) failed\n", dir);
   109  	}
   110  
   111  	// The test harness in go_ios_exec passes the relative working directory
   112  	// in the GoExecWrapperWorkingDirectory property of the app bundle.
   113  	CFStringRef wd_ref = CFBundleGetValueForInfoDictionaryKey(bundle, CFSTR("GoExecWrapperWorkingDirectory"));
   114  	if (wd_ref != NULL) {
   115  		if (!CFStringGetCString(wd_ref, buf, sizeof(buf), kCFStringEncodingUTF8)) {
   116  			fprintf(stderr, "runtime/cgo: cannot get GoExecWrapperWorkingDirectory string\n");
   117  			return;
   118  		}
   119  		if (chdir(buf) != 0) {
   120  			fprintf(stderr, "runtime/cgo: chdir(%s) failed\n", buf);
   121  		}
   122  	}
   123  }
   124  
   125  #endif // TARGET_OS_IPHONE
   126  
   127  void
   128  x_cgo_init(G *g, void (*setg)(void*))
   129  {
   130  	pthread_attr_t attr;
   131  	size_t size;
   132  
   133  	//fprintf(stderr, "x_cgo_init = %p\n", &x_cgo_init); // aid debugging in presence of ASLR
   134  	setg_gcc = setg;
   135  	pthread_attr_init(&attr);
   136  	pthread_attr_getstacksize(&attr, &size);
   137  	g->stacklo = (uintptr)&attr - size + 4096;
   138  	pthread_attr_destroy(&attr);
   139  
   140  #if TARGET_OS_IPHONE
   141  	darwin_arm_init_mach_exception_handler();
   142  	darwin_arm_init_thread_exception_port();
   143  	init_working_dir();
   144  #endif
   145  }
   146
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