可执行程序的编译过程

源文件

#include<stdio.h>

int main()
{
    printf("hello world!");
    return 0;
}

预处理

使用以下命令把.c文件进行宏展开生成.i文件

gcc -E main.c -o main.i

• 编译器对各种预处理命令进行处理，包括头文件包含、宏定义的扩
  展、条件编译的选择等；

编译

使用以下命令把.i文件编译成汇编代码

gcc -S main.i -o main.s

• 将预处理得到的源代码文件，进行“翻译转换”，产生出机器语言的目标程序，得到机器语言的汇编文件；

汇编

使用以下命令把.s文件编译成目标文件

gcc -c main.s -o main.o

此时程序编译成机器码但还不能运行

链接

使用下面命令编译器告诉我们这个程序却什么。

PS D:CodeC> ld main.o
main.o:main.c:(.text+0x9): undefined reference to `__main'
main.o:main.c:(.text+0x15): undefined reference to `printf'

gcc -v main.o -o main

• 链接器ld将各个目标文件组装在一起，解决符号依赖，库依赖关系，并生成可执行文件。

Using built-in specs.
COLLECT_GCC=D:Program Filesmingw64ingcc.exe
COLLECT_LTO_WRAPPER=D:/Program Files/mingw64/bin/../libexec/gcc/x86_64-w64-mingw32/8.1.0/lto-wrapper.exe
Target: x86_64-w64-mingw32
Configured with: ../../../src/gcc-8.1.0/configure --host=x86_64-w64-mingw32 --build=x86_64-w64-mingw32 --target=x86_64-w64-mingw32 --prefix=/mingw64 --with-sysroot=/c/mingw810/x86_64-810-posix-seh-rt_v6-rev0/mingw64 --enable-shared --enable-static --disable-multilib --enable-languages=c,c++,fortran,lto --enable-libstdcxx-time=yes --enable-threads=posix --enable-libgomp --enable-libatomic --enable-lto --enable-graphite --enable-checking=release --enable-fully-dynamic-string --enable-version-specific-runtime-libs --disable-libstdcxx-pch --disable-libstdcxx-debug --enable-bootstrap --disable-rpath --disable-win32-registry --disable-nls --disable-werror --disable-symvers --with-gnu-as 
--with-gnu-ld --with-arch=nocona --with-tune=core2 --with-libiconv --with-system-zlib --with-gmp=/c/mingw810/prerequisites/x86_64-w64-mingw32-static --with-mpfr=/c/mingw810/prerequisites/x86_64-w64-mingw32-static --with-mpc=/c/mingw810/prerequisites/x86_64-w64-mingw32-static 
--with-isl=/c/mingw810/prerequisites/x86_64-w64-mingw32-static --with-pkgversion='x86_64-posix-seh-rev0, Built by MinGW-W64 project' --with-bugurl=https://sourceforge.net/projects/mingw-w64 CFLAGS='-O2 -pipe -fno-ident -I/c/mingw810/x86_64-810-posix-seh-rt_v6-rev0/mingw64/opt/include -I/c/mingw810/prerequisites/x86_64-zlib-static/include -I/c/mingw810/prerequisites/x86_64-w64-mingw32-static/include' CXXFLAGS='-O2 -pipe -fno-ident -I/c/mingw810/x86_64-810-posix-seh-rt_v6-rev0/mingw64/opt/include -I/c/mingw810/prerequisites/x86_64-zlib-static/include -I/c/mingw810/prerequisites/x86_64-w64-mingw32-static/include' CPPFLAGS=' -I/c/mingw810/x86_64-810-posix-seh-rt_v6-rev0/mingw64/opt/include -I/c/mingw810/prerequisites/x86_64-zlib-static/include -I/c/mingw810/prerequisites/x86_64-w64-mingw32-static/include' LDFLAGS='-pipe 
-fno-ident -L/c/mingw810/x86_64-810-posix-seh-rt_v6-rev0/mingw64/opt/lib -L/c/mingw810/prerequisites/x86_64-zlib-static/lib -L/c/mingw810/prerequisites/x86_64-w64-mingw32-static/lib '
Thread model: posix
gcc version 8.1.0 (x86_64-posix-seh-rev0, Built by MinGW-W64 project) 
COMPILER_PATH=D:/Program Files/mingw64/bin/../libexec/gcc/x86_64-w64-mingw32/8.1.0/;D:/Program Files/mingw64/bin/../libexec/gcc/;D:/Program Files/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/8.1.0/../../../../x86_64-w64-mingw32/bin/
LIBRARY_PATH=D:/Program Files/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/8.1.0/;D:/Program Files/mingw64/bin/../lib/gcc/;D:/Program Files/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/8.1.0/../../../../x86_64-w64-mingw32/lib/../lib/;D:/Program Files/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/8.1.0/../../../../lib/;D:/Program Files/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/8.1.0/../../../../x86_64-w64-mingw32/lib/;D:/Program Files/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/8.1.0/../../../
COLLECT_GCC_OPTIONS='-v' '-o' 'main.exe' '-mtune=core2' '-march=nocona'
 D:/Program Files/mingw64/bin/../libexec/gcc/x86_64-w64-mingw32/8.1.0/collect2.exe -plugin D:/Program Files/mingw64/bin/../libexec/gcc/x86_64-w64-mingw32/8.1.0/liblto_plugin-0.dll -plugin-opt=D:/Program Files/mingw64/bin/../libexec/gcc/x86_64-w64-mingw32/8.1.0/lto-wrapper.exe -plugin-opt=-fresolution=C:UserschengAppDataLocalTempccXHP1ki.res -plugin-opt=-pass-through=-lmingw32 -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lgcc_eh -plugin-opt=-pass-through=-lmoldname -plugin-opt=-pass-through=-lmingwex -plugin-opt=-pass-through=-lmsvcrt -plugin-opt=-pass-through=-lpthread -plugin-opt=-pass-through=-ladvapi32 -plugin-opt=-pass-through=-lshell32 -plugin-opt=-pass-through=-luser32 -plugin-opt=-pass-through=-lkernel32 -plugin-opt=-pass-through=-liconv -plugin-opt=-pass-through=-lmingw32 -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lgcc_eh -plugin-opt=-pass-through=-lmoldname -plugin-opt=-pass-through=-lmingwex -plugin-opt=-pass-through=-lmsvcrt --sysroot=C:/mingw810/x86_64-810-posix-seh-rt_v6-rev0/mingw64 -m i386pep -Bdynamic -o main.exe D:/Program Files/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/8.1.0/../../../../x86_64-w64-mingw32/lib/../lib/crt2.o D:/Program Files/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/8.1.0/crtbegin.o -LD:/Program Files/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/8.1.0 -LD:/Program Files/mingw64/bin/../lib/gcc 
-LD:/Program Files/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/8.1.0/../../../../x86_64-w64-mingw32/lib/../lib -LD:/Program Files/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/8.1.0/../../../../lib -LD:/Program Files/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/8.1.0/../../../../x86_64-w64-mingw32/lib -LD:/Program Files/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/8.1.0/../../.. main.o -lmingw32 -lgcc -lgcc_eh -lmoldname -lmingwex -lmsvcrt -lpthread -ladvapi32 -lshell32 -luser32 -lkernel32 -liconv -lmingw32 -lgcc -lgcc_eh -lmoldname -lmingwex -lmsvcrt D:/Program Files/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/8.1.0/crtend.o
COLLECT_GCC_OPTIONS='-v' '-o' 'main.exe' '-mtune=core2' '-march=nocona'

运行

./main