Core: fixed memory leak on configuration reload with PCRE2. In ngx_regex_cleanup() allocator wasn't configured when calling pcre2_compile_context_free() and pcre2_match_data_free(), resulting in no ngx_free() call and leaked memory. Fix is ensure that allocator is configured for global allocations, so that ngx_free() is actually called to free memory. Additionally, ngx_regex_compile_context was cleared in ngx_regex_module_init(). It should be either not cleared, so it will be freed by ngx_regex_cleanup(), or properly freed. Fix is to not clear it, so ngx_regex_cleanup() will be able to free it. Reported by ZhenZhong Wu, https://mailman.nginx.org/pipermail/nginx-devel/2023-September/3Z5FIKUDRN2WBSL3JWTZJ7SXDA6YIWPB.html

/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_CRC_H_INCLUDED_
#define _NGX_CRC_H_INCLUDED_


#include <ngx_config.h>
#include <ngx_core.h>


/* 32-bit crc16 */

static ngx_inline uint32_t
ngx_crc(u_char *data, size_t len)
{
    uint32_t  sum;

    for (sum = 0; len; len--) {

        /*
         * gcc 2.95.2 x86 and icc 7.1.006 compile
         * that operator into the single "rol" opcode,
         * msvc 6.0sp2 compiles it into four opcodes.
         */
        sum = sum >> 1 | sum << 31;

        sum += *data++;
    }

    return sum;
}


#endif /* _NGX_CRC_H_INCLUDED_ */