由于php7.4开启gd库是所需的依赖版本比较高，所以不管是ubantu还是centos,安装php7.4扩展的时候尽量把依赖先安装好，避免安装到半路，四处是“报错”

一、安装依赖包libpng、libzip、zlib、freetype、libgd、libjpeg

libpng

wget https://nchc.dl.sourceforge.net/project/libpng/libpng16/1.6.39/libpng-1.6.39.tar.xz
#xz解压
xz -d libpng-1.6.39.tar.xz 
#tar解压
tar xvf libpng-1.6.39.tar
cd libpng-1.6.39
./configure --prefix=/usr/local/libpng --enable-shared
make
make install

libzip

wget https://nih.at/libzip/libzip-1.2.0.tar.gz
tar -zxvf libzip-1.2.0.tar.gz
cd libzip-1.2.0
./configure
make
make install

zlib

wget http://www.zlib.net/zlib-1.2.13.tar.gz
tar -xzvf zlib-1.2.13.tar.gz
cd zlib-1.2.13
./configure --prefix=/usr/local/zlib --enable-shared
make
make install

freetype

wget https://download.savannah.gnu.org/releases/freetype/freetype-2.10.1.tar.gz
tar -xzvf freetype-2.10.1.tar.gz
cd freetype-2.10.1
./configure --prefix=/usr/local/freetype --enable-shared
make
make install

libgd

wget https://github.com/libgd/libgd/releases/download/gd-2.3.3/libgd-2.3.3.tar.gz
tar -xzvf libgd-2.3.3.tar.gz
cd libgd-2.3.3
./configure --enable-shared
make
make install
make clean
make distclean

libjpeg

wget http://www.ijg.org/files/jpegsrc.v9d.tar.gz
tar -xzvf jpegsrc.v9d.tar.gz
cd jpeg-9d
./configure --prefix=/usr/local/libjpeg --enable-shared
make
make install

二. 进入php源码目录安装gd扩展

cd ~/php-7.4.19/ext/gd
#执行phpize
/usr/local/php/bin/phpize 
#编译
./configure --enable-gd --with-php-config=/usr/local/php/bin/php-config --with-jpeg=/usr/local/libjpeg --with-freetype=/usr/local/freetype
make
make install

三.执行编译过程中报错解决方案：

No package 'libpng' found

解决：

yum install -y libpng-devel

No package 'libxslt' found

解决：

yum install -y libxslt-devel

No package 'libjpeg' found

解决：

yum install -y libjpeg-devel

No package 'freetype2' found

解决：

yum install -y freetype-devel

由于我编译的过程中出现了这四个错误，我就记录了这四个错误，后续我会把一部分扩展错误整理出来，放到一篇文章中做参考