从汇编的角度分析C语言（一）char *p与char p[]的区别
C语言代码：
#include <stdlib.h>
#include <stdio.h>
void main()
{
char array1[] = { "123456" };
char *pointer1 = "123456";
}
汇编代码：
(gdb) disassemble main
Dump of assembler code for function main:
0x08048394 <+0>: push %ebp
0x08048395 <+1>: mov %esp,%ebp
0x08048397 <+3>: sub $0x10,%esp
0x0804839a <+6>: movl $0x34333231,-0xb(%ebp)
0x080483a1 <+13>: movw $0x3635,-0x7(%ebp)
0x080483a7 <+19>: movb $0x0,-0x5(%ebp)
0x080483ab <+23>: movl $0x8048484,-0x4(%ebp)
0x080483b2 <+30>: leave
0x080483b3 <+31>: ret
End of assembler dump.
(gdb) x/7xb 0x8048484
0x8048484 <__dso_handle+4>: 0x31 0x32 0x33 0x34 0x35 0x36 0x00
(gdb)
从<+6><+13><+19>三行可以看出，程序为array1分配了7bytes的内存空间，用来存储“123456”+‘\0’。
而<+23>行表示将地址0x8048484赋给了pointer1，我们可以查看内存0x8048484之后内容，7bytes正好为“123456”+‘\0’，这里pointer1只是一个指针，并没有为其分配内存单元。
那么下面的这段代码就不难理解了。
#include <stdlib.h>
#include <stdio.h>
void main()
{
char array1[] = { "123456" };
char array2[] = { "123456" };
char *pointer1 = "123456";
char *pointer2 = "123456";
}
汇编代码：
(gdb) disassemble main
Dump of assembler code for function main:
0x08048394 <+0>: push %ebp
0x08048395 <+1>: mov %esp,%ebp
0x08048397 <+3>: sub $0x20,%esp
0x0804839a <+6>: movl $0x34333231,-0xf(%ebp)
0x080483a1 <+13>: movw $0x3635,-0xb(%ebp)
0x080483a7 <+19>: movb $0x0,-0x9(%ebp)
0x080483ab <+23>: movl $0x34333231,-0x16(%ebp)
0x080483b2 <+30>: movw $0x3635,-0x12(%ebp)
0x080483b8 <+36>: movb $0x0,-0x10(%ebp)
0x080483bc <+40>: movl $0x8048494,-0x4(%ebp)
0x080483c3 <+47>: movl $0x8048494,-0x8(%ebp)
0x080483ca <+54>: leave
0x080483cb <+55>: ret
End of assembler dump.
(gdb) x/7xb 0x8048494
0x8048494 <__dso_handle+4>: 0x31 0x32 0x33 0x34 0x35 0x36 0x00
(gdb)
接着这段代码也就顺其自然了！
(gdb) disassemble main
Dump of assembler code for function main:
0x08048394 <+0>: push %ebp
0x08048395 <+1>: mov %esp,%ebp
0x08048397 <+3>: sub $0x20,%esp
0x0804839a <+6>: movl $0x34333231,-0xf(%ebp)
0x080483a1 <+13>: movw $0x3635,-0xb(%ebp)
0x080483a7 <+19>: movb $0x0,-0x9(%ebp)
0x080483ab <+23>: movl $0x34333231,-0x16(%ebp)
0x080483b2 <+30>: movw $0x3635,-0x12(%ebp)
0x080483b8 <+36>: movb $0x0,-0x10(%ebp)
0x080483bc <+40>: movl $0x8048494,-0x4(%ebp)
0x080483c3 <+47>: movl $0x804849b,-0x8(%ebp)
0x080483ca <+54>: leave
0x080483cb <+55>: ret
End of assembler dump.
(gdb) x/7xb 0x8048494
0x8048494 <__dso_handle+4>: 0x31 0x32 0x33 0x34 0x35 0x36 0x00
(gdb) x/9xb 0x804849b
0x804849b <__dso_handle+11>: 0x31 0x32 0x33 0x34 0x35 0x36 0x37 0x38
0x80484a3 <__dso_handle+19>: 0x00
(gdb)
摘自 sg131971（七夜）的学习笔记
补充：软件开发 , C语言 ,
