A, gcc compiler processes
GCC C compiler to compile a code, you need to go through the following four steps:
pretreatment (Preprocessing): .c source file for preprocessing, generating .i file.
Compilation (compilation): .i file compiled to generate .s assembly files.
Compilation (assembly): to assemble .s files, generates .o object files.
Links (linking): .o file to be linked to produce an executable file.
Two, gcc command
2.1 gcc command format definition
2.2 gcc commands commonly used parameters
2.2.1 Basic parameters
-E: preprocessed source file only, not compiled. The results output directly to the screen.
-S: preprocessing of the source file, the compiler, without compilation. .S results saved in a file form, with the same name as the source .c files.
-c: source file preprocessing, compilation, assembly, do not link to it. Save the results in a .o file format, with the same name as the source .c files.
-save-temps: Save and compile all documents produced during the middle of. Intermediate file name with .c source file of the same name, suffix .i, .s, .o
2.2.2 debugging parameters
-o: any type of output are stored to the specified file.
-Wall：打开编译器的警告标志，尽可能多的输出警告信息。强烈建议，编译时始终带上 -Wall 选项。
-Werror：将所有的警告当成错误处理，必须消除警告才能继续编译。
2.2.3 函数库参数
-llibrary：手动指定函数库library参与链接。库名为library，文件名为liblibrary.a或liblibrary.so
-Ldir：手动添加一个路径dir，用以搜索库文件（.a 或 .so 文件，即手动指定的函数库文件的所在目录）。
-Idir：手动添加一个路径dir，用以搜索头文件（.h 文件，即源码内#include要包含的文件的所在目录）。
