github.com/zebozhuang/go@v0.0.0-20200207033046-f8a98f6f5c5d/src/runtime/testdata/testprogcgo/tracebackctxt_c.c (about)

     1  // Copyright 2016 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  // The C definitions for tracebackctxt.go. That file uses //export so
     6  // it can't put function definitions in the "C" import comment.
     7  
     8  #include <stdlib.h>
     9  #include <stdint.h>
    10  
    11  // Functions exported from Go.
    12  extern void G1(void);
    13  extern void G2(void);
    14  
    15  void C1() {
    16  	G1();
    17  }
    18  
    19  void C2() {
    20  	G2();
    21  }
    22  
    23  struct cgoContextArg {
    24  	uintptr_t context;
    25  };
    26  
    27  struct cgoTracebackArg {
    28  	uintptr_t  context;
    29  	uintptr_t  sigContext;
    30  	uintptr_t* buf;
    31  	uintptr_t  max;
    32  };
    33  
    34  struct cgoSymbolizerArg {
    35  	uintptr_t   pc;
    36  	const char* file;
    37  	uintptr_t   lineno;
    38  	const char* func;
    39  	uintptr_t   entry;
    40  	uintptr_t   more;
    41  	uintptr_t   data;
    42  };
    43  
    44  // Uses atomic adds and subtracts to catch the possibility of
    45  // erroneous calls from multiple threads; that should be impossible in
    46  // this test case, but we check just in case.
    47  static int contextCount;
    48  
    49  int getContextCount() {
    50  	return __sync_add_and_fetch(&contextCount, 0);
    51  }
    52  
    53  void tcContext(void* parg) {
    54  	struct cgoContextArg* arg = (struct cgoContextArg*)(parg);
    55  	if (arg->context == 0) {
    56  		arg->context = __sync_add_and_fetch(&contextCount, 1);
    57  	} else {
    58  		if (arg->context != __sync_add_and_fetch(&contextCount, 0)) {
    59  			abort();
    60  		}
    61  		__sync_sub_and_fetch(&contextCount, 1);
    62  	}
    63  }
    64  
    65  void tcTraceback(void* parg) {
    66  	int base, i;
    67  	struct cgoTracebackArg* arg = (struct cgoTracebackArg*)(parg);
    68  	if (arg->context == 0) {
    69  		// This shouldn't happen in this program.
    70  		abort();
    71  	}
    72  	// Return a variable number of PC values.
    73  	base = arg->context << 8;
    74  	for (i = 0; i < arg->context; i++) {
    75  		if (i < arg->max) {
    76  			arg->buf[i] = base + i;
    77  		}
    78  	}
    79  }
    80  
    81  void tcSymbolizer(void *parg) {
    82  	struct cgoSymbolizerArg* arg = (struct cgoSymbolizerArg*)(parg);
    83  	if (arg->pc == 0) {
    84  		return;
    85  	}
    86  	// Report two lines per PC returned by traceback, to test more handling.
    87  	arg->more = arg->file == NULL;
    88  	arg->file = "tracebackctxt.go";
    89  	arg->func = "cFunction";
    90  	arg->lineno = arg->pc + (arg->more << 16);
    91  }