auto/cc/name脚本分析-part6
在分析编译器配置总控代码之前,我们先来分析auto/cc/name脚本,此脚本主要是完成编译器名称的设置,从而在后续脚本中可以根据编译器名称选择对应的编译器。
参看:http://blog.csdn.net/poechant/article/details/7355325
1. auto/cc/name脚本
在进行具体的脚本分析之前,我们这里贴出其源代码:
# Copyright (C) Igor Sysoev
# Copyright (C) Nginx, Inc.
if [ "$NGX_PLATFORM" != win32 ]; then
ngx_feature="C compiler"
ngx_feature_name=
ngx_feature_run=yes
ngx_feature_incs=
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test=
. auto/feature
if [ $ngx_found = no ]; then
echo
echo $0: error: C compiler $CC is not found
echo
exit 1
fi
fi
if [ "$CC" = cl ]; then
NGX_CC_NAME=msvc
echo " + using Microsoft Visual C++ compiler"
elif [ "$CC" = wcl386 ]; then
NGX_CC_NAME=owc
echo " + using Open Watcom C compiler"
elif [ "$CC" = bcc32 ]; then
NGX_CC_NAME=bcc
echo " + using Borland C++ compiler"
elif `$CC -V 2>&1 | grep '^Intel(R) C' >/dev/null 2>&1`; then
NGX_CC_NAME=icc
echo " + using Intel C++ compiler"
elif `$CC -v 2>&1 | grep 'gcc version' >/dev/null 2>&1`; then
NGX_CC_NAME=gcc
echo " + using GNU C compiler"
elif `$CC -v 2>&1 | grep '\(clang\|LLVM\) version' >/dev/null 2>&1`; then
NGX_CC_NAME=clang
echo " + using Clang C compiler"
elif `$CC -V 2>&1 | grep 'Sun C' >/dev/null 2>&1`; then
NGX_CC_NAME=sunc
echo " + using Sun C compiler"
elif `$CC -V 2>&1 | grep '^Compaq C' >/dev/null 2>&1`; then
NGX_CC_NAME=ccc
echo " + using Compaq C compiler"
elif `$CC -V 2>&1 | grep '^aCC: ' >/dev/null 2>&1`; then
NGX_CC_NAME=acc
echo " + using HP aC++ compiler"
else
NGX_CC_NAME=unknown
fi
此脚本主要是根据$CC
的名称设置NGX_CC_NAME
的值。如下我们队该脚本进行简单分析。
2. C编译器特征判断
脚本代码如下:
if [ "$NGX_PLATFORM" != win32 ]; then
ngx_feature="C compiler"
ngx_feature_name=
ngx_feature_run=yes
ngx_feature_incs=
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test=
. auto/feature
if [ $ngx_found = no ]; then
echo
echo $0: error: C compiler $CC is not found
echo
exit 1
fi
fi
Windows 平台的编译器叫做MSVC,其他平台的都统称为C Compiler。上述脚本首先判断是否为win32平台,如果不是的话,则判断其是否具有c编译器特征。根据前面我们队auto/feature脚本的介绍,其会生成如下内容的autotest.c文件:
#include <sys/types.h>
int main() {
;
return 0;
}
编译并运行此脚本,ngx_found值会被设置为yes。
假如ngx_found值为no的话,则会打印出:
./auto/cc/name: error: C compiler $CC is not found
然后退出整个脚本的运行。
3. 设置NGX_CC_NAME
脚本内容如下:
if [ "$CC" = cl ]; then
NGX_CC_NAME=msvc
echo " + using Microsoft Visual C++ compiler"
elif [ "$CC" = wcl386 ]; then
NGX_CC_NAME=owc
echo " + using Open Watcom C compiler"
elif [ "$CC" = bcc32 ]; then
NGX_CC_NAME=bcc
echo " + using Borland C++ compiler"
elif `$CC -V 2>&1 | grep '^Intel(R) C' >/dev/null 2>&1`; then
NGX_CC_NAME=icc
echo " + using Intel C++ compiler"
elif `$CC -v 2>&1 | grep 'gcc version' >/dev/null 2>&1`; then
NGX_CC_NAME=gcc
echo " + using GNU C compiler"
elif `$CC -v 2>&1 | grep '\(clang\|LLVM\) version' >/dev/null 2>&1`; then
NGX_CC_NAME=clang
echo " + using Clang C compiler"
elif `$CC -V 2>&1 | grep 'Sun C' >/dev/null 2>&1`; then
NGX_CC_NAME=sunc
echo " + using Sun C compiler"
elif `$CC -V 2>&1 | grep '^Compaq C' >/dev/null 2>&1`; then
NGX_CC_NAME=ccc
echo " + using Compaq C compiler"
elif `$CC -V 2>&1 | grep '^aCC: ' >/dev/null 2>&1`; then
NGX_CC_NAME=acc
echo " + using HP aC++ compiler"
else
NGX_CC_NAME=unknown
fi
上述脚本设置NGX_CC_NAME
,并且打印出对应的信息。