My whole stack of the road -C basis of the C language program run flow

My whole stack of the road -C basis of the C language program run flow

My whole stack of the road

4.1 C program running processes

Programs written in C language must pass the written source files -> Pretreatment -> compile -> compile -> run these processes after the link.

• Pretreatment
  Pretreatment mainly macro substitution, include headers and conditional compilation extension memo to delete the pre-compilation stage is generally generated file .i.
• Compiler
  Compiler mainly to good pre-generated file compilation of documents, compiled file extension is usually .s.
• Compilation
  compilation compilation of documents generated mainly to a binary file, the file extension after the compilation is usually .o.
• Links
  Links are mainly individual binary files, library functions, startup code executable file.

Then write the source program_running_process.c, and then combine the various options GCC compiler on Windows implementations provided pre-compiler, assembler, linker, on GCC installation and configuration can refer to the
Visual Studio Code for content Hello World section.

#include <stdio.h>
//定义浮点型的常量
#define PI 3.14
/*
    C语言程序的运行流程
    @author tony [email protected]
    @version  2019/08/20
*/
int main(int argc, char* argv[]) {

    printf("PI =%lf\n", PI);
    return 0;
}

Pretreatment using gcc -E option can be realized, which represents the name of the output file -o

D:\workspace\c\visualstuido2019\c-core-programming\c-core-programming-foundational\c-core-programming-foundational>gcc -E  program_runing_process.c -o program_runing_process.i

After the pretreatment, the resulting file size is 54kb program_running_process.i

When preprocessing is complete, the defined constants are replaced by actual values, and the contents of the file header contains #include also copied to the pre-generated files

Compiling by gcc -S option

D:\workspace\c\visualstuido2019\c-core-programming\c-core-programming-foundational\c-core-programming-foundational>gcc -S program_runing_process.i -o program_runing_process.s

Compiler will generate an assembly file

 .file	"program_runing_process.c"
    .text
    .def	__main;	.scl	2;	.type	32;	.endef
    .section .rdata,"dr"
.LC1:
    .ascii "PI =%lf\12\0"
    .text
    .globl	main
    .def	main;	.scl	2;	.type	32;	.endef
    .seh_proc	main
main:
    pushq	%rbp
    .seh_pushreg	%rbp
    movq	%rsp, %rbp
    .seh_setframe	%rbp, 0
    subq	$32, %rsp
    .seh_stackalloc	32
    .seh_endprologue
    movl	%ecx, 16(%rbp)
    movq	%rdx, 24(%rbp)
    call	__main
    movq	.LC0(%rip), %rax
    movq	%rax, %rdx
    movq	%rdx, %xmm1
    movq	%rax, %rdx
    leaq	.LC1(%rip), %rcx
    call	printf
    movl	$0, %eax
    addq	$32, %rsp
    popq	%rbp
    ret
    .seh_endproc
    .section .rdata,"dr"
    .align 8
.LC0:
    .long	1374389535
    .long	1074339512
    .ident	"GCC: (x86_64-posix-seh-rev0, Built by MinGW-W64 project) 7.3.0"
    .def	printf;	.scl	2;	.type	32;	.endef

Compiled by gcc -c option to achieve

D:\workspace\c\visualstuido2019\c-core-programming\c-core-programming-foundational\c-core-programming-foundational>gcc -c program_runing_process.s -o program_runing_process.o

Link gcc does not provide options here as long as the implementation of gcc program_running_process.o -o program_running_process.exe will link an executable file

D:\workspace\c\visualstuido2019\c-core-programming\c-core-programming-foundational\c-core-programming-foundational>gcc program_runing_process.o -o program_runing_process.exe

Executable file extension .exe in windows by default, of course gcc compiler does not care about the suffix, if you install ubuntu or macOS the gcc, the C compiler can also generate executable .exe suffix.