这两个命令用来编译release版本的二进制文件

gn gen out/release –args=”is_component_build=false is_debug=false”

ninja -C out/release nginx-1.18.0_ipdb

默认系统头文件和依赖库

build/linux/debian_sid_amd64-sysroot 这个目录相当于根目录, usr/lib和usr/include 分别放了依赖库和头文件

chromium移除了这两个文件,不知道为何, 会导致nginx 编译失败,目前解决办法是从旧版本拷贝过去

build/linux/debian_sid_amd64-sysroot/usr/lib/x86_64-linux-gnu/libcrypt.so

build/linux/debian_sid_amd64-sysroot/usr/include/crypt.h

修改编译参数

build/config/compiler/BUILD.gn, 比如nginx 可能需要把这个特性关掉

if (!is_nacl && !use_libfuzzer) {
#cflags += [ “-Wunreachable-code” ]
}

编译方式

executable(“fssnginx-1.18.0_ipdb”) {
sources = [
“/root/fssnginx/nginx-1.18.0/objs/ngx_modules.c”,
“/root/fssnginx/nginx-1.18.0/src/core/nginx.c”,

….

]

include_dirs = [
“/root/fssnginx/nginx-1.18.0/src/core”,
“/root/fssnginx/nginx-1.18.0/src/event”,
“/root/fssnginx/nginx-1.18.0/src/event/modules”,
“/root/fssnginx/nginx-1.18.0/src/os/unix”,
“/root/fssnginx/nginx-1.18.0/nginx_upstream_check_module-master”,
“/root/fssnginx/nginx-1.18.0/ngx_devel_kit-0.3.0/objs”,
“/root/fssnginx/nginx-1.18.0/objs/addon/ndk”,
“/root/fssnginx/nginx-1.18.0/lua-nginx-module-0.10.13/src/api”,
“/root/fssnginx/nginx-1.18.0/pcre-8.42”,
“/root/fssnginx/nginx-1.18.0/zlib-1.2.11”,
“/root/fssnginx/nginx-1.18.0/objs”,
“/root/fssnginx/nginx-1.18.0/src/http”,
“/root/fssnginx/nginx-1.18.0/src/http/modules”,
“/root/fssnginx/nginx-1.18.0/src/http/v2”,
“/root/fssnginx/nginx-1.18.0/src/http”,
“/root/fssnginx/nginx-1.18.0/ngx_devel_kit-0.3.0/src”,
“/root/fssnginx/nginx-1.18.0/ngx_devel_kit-0.3.0/src”,
“/root/fssnginx/nginx-1.18.0/ngx_devel_kit-0.3.0/objs”,
“/root/fssnginx/nginx-1.18.0/objs/addon/ndk”,
“/root/fssnginx/nginx-1.18.0/luajit/include/luajit-2.0”,
“/root/fssnginx/nginx-1.18.0/quic_module/chromium”,
]
deps = [
“:epoll_quic_tools”,
“:epoll_server”,
“:net”,
“:simple_quic_tools”,
“//base”,
“//third_party/boringssl”,
]
lib_dirs = [
“/root/fssnginx/nginx-1.18.0/json-c/lib”,
“/root/fssnginx/nginx-1.18.0/luajit/lib”,
]
libs = [
“/root/fssnginx/nginx-1.18.0/pcre-8.42/.libs/libpcre.a”,
“/root/fssnginx/nginx-1.18.0/zlib-1.2.11/libz.a”,
“luajit-5.1”,
“json-c”,
“crypt”,
]
cflags_c = [
“-D_FORTIFY_SOURCE=2”,
“-DTCP_FASTOPEN=23”,
“-DNDK_SET_VAR”,
]
}

最近维护一个古老代码的时候,在AS7里边编译的时候出现了不少错误,比如:

warning: comparison between pointer and integer, 这是代码 strptime(current_time, “%a%n%b%n%d%n%H:%M:%S%n%Y”, &tm) == NULL) 产生的

还有, warning: incompatible implicit declaration of built-in function ‘snprintf’, 这是类似 snprintf(path, sizeof(path), “%s/arc_%s”, archdir, com->cat) 的代码产生的

查了下,strptime的异常返回值确实是NULL, http://man7.org/linux/man-pages/man3/strptime.3.html

If strptime() fails to match all of the format string and therefore an error occurred, the function returns NULL.

一般来说, 类似的snprintf错误 添加 #include<stdlib.h>就好,但是这个古老代码里边已经有这个了

在代码的开头发现了这个东西

define _XOPEN_SOURCE

       _XOPEN_SOURCE
              Defining this macro causes header files to expose definitions as
              follows:

              o  Defining  with  any  value  exposes definitions conforming to POSIX.1, POSIX.2, and XPG4.

              o  The value 500 or greater additionally exposes definitions for SUSv2 (UNIX 98).

              o  (Since  glibc  2.2)  The  value  600  or greater additionally exposes  definitions  for   SUSv3   (UNIX   03;   i.e.,   the POSIX.1-2001  base  specification plus the XSI extension) and C99 definitions.

              o  (Since glibc 2.10) The  value  700  or  greater  additionally exposes  definitions  for  SUSv4 (i.e., the POSIX.1-2008 base specification plus the XSI extension).

https://linux.cn/man7/feature_test_macros.7.html, 初略的说,大概是不同的值会影响某些函数和库的一些标准行为,而默认的_xopen_soure 不带参数会被认为是<500

#define _XOPEN_SOURCE        /* or any value < 500 */

所以需要修正这个模式,添加一个标准即可,由于代码比较古老,修改为500和600都可以编译通过