gcc编译过程和重要参数

hello.c

#include <stdio.h>

main() {
printf("hello world\n");
}

编译过程

#####打印gcc的版本、target、编译参数、线程模型
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-redhat-linux/8/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-redhat-linux
Configured with: ../configure --enable-bootstrap --enable-languages=c,c++,fortran,lto --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-shared --enable-threads=posix --enable-checking=release --enable-multilib --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-gcc-major-version-only --with-linker-hash-style=gnu --enable-plugin --enable-initfini-array --with-isl --disable-libmpx --enable-offload-targets=nvptx-none --without-cuda-driver --enable-gnu-indirect-function --enable-cet --with-tune=generic --with-arch_32=x86-64 --build=x86_64-redhat-linux
Thread model: posix
gcc version 8.4.1 20200928 (Red Hat 8.4.1-1) (GCC)

#####预处理(处理宏命令,条件编译，头文件等)、编译(语法检查，生产汇编文件.s)
COLLECT_GCC_OPTIONS='-v' '-mtune=generic' '-march=x86-64'
 /usr/libexec/gcc/x86_64-redhat-linux/8/cc1 -quiet -v hello.c -quiet -dumpbase hello.c -mtune=generic -march=x86-64 -auxbase hello -version -o /tmp/ccP7pCvS.s
GNU C17 (GCC) version 8.4.1 20200928 (Red Hat 8.4.1-1) (x86_64-redhat-linux)
        compiled by GNU C version 8.4.1 20200928 (Red Hat 8.4.1-1), GMP version 6.1.2, MPFR version 3.1.6-p2, MPC version 1.0.2, isl version isl-0.16.1-GMP

warning: MPC header version 1.0.2 differs from library version 1.1.0.
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
ignoring nonexistent directory "/usr/lib/gcc/x86_64-redhat-linux/8/include-fixed"
ignoring nonexistent directory "/usr/lib/gcc/x86_64-redhat-linux/8/../../../../x86_64-redhat-linux/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/lib/gcc/x86_64-redhat-linux/8/include
 /usr/local/include
 /usr/include
End of search list.
GNU C17 (GCC) version 8.4.1 20200928 (Red Hat 8.4.1-1) (x86_64-redhat-linux)
        compiled by GNU C version 8.4.1 20200928 (Red Hat 8.4.1-1), GMP version 6.1.2, MPFR version 3.1.6-p2, MPC version 1.0.2, isl version isl-0.16.1-GMP

warning: MPC header version 1.0.2 differs from library version 1.1.0.
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: ba4472413baf586bad38c66b3c26fe90
hello.c:3:1: warning: return type defaults to ‘int’ [-Wimplicit-int]
 main() {
 ^~~~
#####汇编(转化为机器码,平台x86-64)
COLLECT_GCC_OPTIONS='-v' '-mtune=generic' '-march=x86-64'
 as -v --64 -o /tmp/ccm6m8LR.o /tmp/ccP7pCvS.s
GNU assembler version 2.30 (x86_64-redhat-linux) using BFD version version 2.30-93.el8
#####链接
COMPILER_PATH=/usr/libexec/gcc/x86_64-redhat-linux/8/:/usr/libexec/gcc/x86_64-redhat-linux/8/:/usr/libexec/gcc/x86_64-redhat-linux/:/usr/lib/gcc/x86_64-redhat-linux/8/:/usr/lib/gcc/x86_64-redhat-linux/
LIBRARY_PATH=/usr/lib/gcc/x86_64-redhat-linux/8/:/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/:/lib/../lib64/:/usr/lib/../lib64/:/usr/lib/gcc/x86_64-redhat-linux/8/../../../:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-v' '-mtune=generic' '-march=x86-64'
 /usr/libexec/gcc/x86_64-redhat-linux/8/collect2 -plugin /usr/libexec/gcc/x86_64-redhat-linux/8/liblto_plugin.so -plugin-opt=/usr/libexec/gcc/x86_64-redhat-linux/8/lto-wrapper -plugin-opt=-fresolution=/tmp/cc2qvFZQ.res -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lc -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lgcc_s --build-id --no-add-needed --eh-frame-hdr --hash-style=gnu -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2 /usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o /usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crti.o /usr/lib/gcc/x86_64-redhat-linux/8/crtbegin.o -L/usr/lib/gcc/x86_64-redhat-linux/8 -L/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64 -L/lib/../lib64 -L/usr/lib/../lib64 -L/usr/lib/gcc/x86_64-redhat-linux/8/../../.. /tmp/ccm6m8LR.o -lgcc --as-needed -lgcc_s --no-as-needed -lc -lgcc --as-needed -lgcc_s --no-as-needed /usr/lib/gcc/x86_64-redhat-linux/8/crtend.o /usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crtn.o
COLLECT_GCC_OPTIONS='-v' '-mtune=generic' '-march=x86-64'

常用参数

-E 只预处理
-S 到编译
-c 到汇编
-pie 生成位置无关二进制
-shared 生产库文件
-W warning配置
-Wa,<options> 汇编配置
-Wp,<options> 预处理配置
-Wl,<options> 连接器配置
-m 交叉编译配置
-g 保留debug信息
-O1 优化级别