gcc_aix_ppc64.c

Documentation: runtime/cgo

     1// Copyright 2019 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/*
     6 * On AIX, call to _cgo_topofstack and Go main are forced to be a longcall.
     7 * Without it, ld might add trampolines in the middle of .text section
     8 * to reach these functions which are normally declared in runtime package.
     9 */
    10extern int __attribute__((longcall)) __cgo_topofstack(void);
    11extern int __attribute__((longcall)) runtime_rt0_go(int argc, char **argv);
    12extern void __attribute__((longcall)) _rt0_ppc64_aix_lib(void);
    13
    14int _cgo_topofstack(void) {
    15	return __cgo_topofstack();
    16}
    17
    18int main(int argc, char **argv) {
    19	return runtime_rt0_go(argc, argv);
    20}
    21
    22static void libinit(void) __attribute__ ((constructor));
    23
    24/*
    25 * libinit aims to replace .init_array section which isn't available on aix.
    26 * Using __attribute__ ((constructor)) let gcc handles this instead of
    27 * adding special code in cmd/link.
    28 * However, it will be called for every Go programs which has cgo.
    29 * Inside _rt0_ppc64_aix_lib(), runtime.isarchive is checked in order
    30 * to know if this program is a c-archive or a simple cgo program.
    31 * If it's not set, _rt0_ppc64_ax_lib() returns directly.
    32 */
    33static void libinit() {
    34	_rt0_ppc64_aix_lib();
    35}
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