GCC __typeof__ __extension__
来源：互联网 发布：微信游戏源码带后台 编辑：程序博客网 时间：2024/04/30 08:28
The __typeof__ Operator
The __typeof__ operator is another way to refer to the type of an expression. This feature is provided for compatiblity with the gcc compiler.
The syntax of this operator keyword looks like sizeof , but the construct acts semantically like a type-name defined with typedef .
__typeof__ ( expression )
__typeof__ ( type-name )
There are two ways of writing the argument to __typeof__ : with an expression or with a type.
The following is an example with an expression. This example assumes that x is an array of int s; the type described is int :
__typeof__(x[0](1))
The following is an example with a type-name as the argument. The type described is that of pointers to int :
__typeof__(int *)
A __typeof__ construct can be used anywhere a typedef name can be used. For example, you can use it in a declaration, in a cast, or inside a sizeof or __typeof__ operator:
__typeof__(*x) y; // Declares y with the type of what x points to. __typeof__(*x) y[4]; // Declares y as an array of such values. __typeof__(__typeof__(char *)[4]) y; // Declares y as an array of // pointers to characters:
The last example (the nested __typeof__ operators) is equivalent to the following traditional C declaration:
char *y[4];
To see the meaning of the declaration using __typeof__ , and why it might be a useful way to write it that way, let's rewrite it with these macros:
#define pointer(T) __typeof__(T *) #define array(T, N) __typeof__(T [N])
Now the declaration can be rewritten this way:
array (pointer (char), 4) y;
Thus, array (pointer (char), 4) is the type of arrays of 4 pointers to char .
GCC
在学习之前需要了解的是，在使用gcc或g++执行编译的时候，具体的过程如何。如下所示：
1、预处理，生成.i的文件 [预处理器cpp]
2、将预处理后的文件不转换成汇编语言，生成文件.s [编译器egcs]
3、有汇编变为目标代码(机器代码)生成.o的文件 [汇编器as]
4、连接目标代码,生成可执行程序 [链接器ld]
通过对常用的选项，举例学习实践如下。
主要学习如下gcc选项：
-o、-x、-c、-S、-E、-pipe
主要就是使用一个最简单的C程序HelloWorld.c，如下所示：
#include <stdio.h>
int main()
{
printf("Hello,the world!/n");
return 0;
}
后面不再说明，除非特殊说明，否则就是指这一段简单的程序。
1、默认编译
比如，你写了一个最简单的C程序HelloWorld.c，如下所示：
#include <stdio.h>
int main()
{
printf("Hello,the world!/n");
return 0;
}
编译运行：
[root@shirdrn junys]# gcc HelloWorld.c
[root@shirdrn junys]# ./a.out
Hello,the world!
这时，会默认生成一个a.out文件。运行就能看到程序运行输出“Hello,the world!”。
2、-o 选项
指定目标名称,缺省的时候,gcc 编译出来的文件是a.out,如果你想指定一个其他的名称时，可以使用-o选项。
编译运行：
[root@shirdrn junys]# gcc -o HelloWorld HelloWorld.c
[root@shirdrn junys]# ./HelloWorld
Hello,the world!
就能看到程序运行输出“Hello,the world!”。
3、 -x 选项
具体格式为： -x language filename
其中，language表示语言，例如C语言的后缀名称是.c的，而C++的后缀名是.C或者.cpp；filename表示一个待执行的程序文件，可以使用任何扩展名。
实际上，该-x选项会自动忽略filename程序文件的扩展名，而将filename看成是一个language语言的程序文件并进行编译。
比如，你写了一个最简单的C程序，但是完整文件名称为HelloWorld.shirdrn，扩展名为.shridrn，代码如下所示：
#include <stdio.h>
int main()
{
printf("Hello,the world!/n");
return 0;
}
编译运行：
[root@shirdrn junys]# gcc -o HelloWorld.srn -x c HelloWorld.shirdrn
[root@shirdrn junys]# ./HelloWorld.srn
Hello,the world!
4、-c 选项
编译、汇编到目标代码，不进行链接，也就是只生成目标文件(扩展名为.o的目标文件)。
使用-c选项进行编译：
[root@shirdrn junys]# gcc -c HelloWorld.c
这时，可以看到，只是生成了一个HelloWorld.o的目标文件，当然它是一个二进制文件了。
5、 -S 选项
编译到汇编语言，不进行汇编和链接，就是指把文件编译成为汇编代码。
使用-S选项进行编译：
[root@shirdrn junys]# gcc -S HelloWorld.c
可以看到，生成了一个HelloWorld.s文件，使用“文本编辑器”查看该文件，可以看到生成的汇编代码，如下所示：
.file "HelloWorld.c"
.section .rodata
.LC0:
.string "Hello,the world!"
.text
.globl main
.type main, @function
main:
leal 4(%esp), %ecx
andl $-16, %esp
pushl -4(%ecx)
pushl %ebp
movl %esp, %ebp
pushl %ecx
subl $4, %esp
movl $.LC0, (%esp)
call puts
movl $0, %eax
addl $4, %esp
popl %ecx
popl %ebp
leal -4(%ecx), %esp
ret
.size main, .-main
.ident "GCC: (GNU) 4.1.2 20070502 (Red Hat 4.1.2-12)"
.section .note.GNU-stack,"",@progbits
还没有将汇编代码汇编成目标文件。
6、 -E 选项
仅作预处理，不进行编译、汇编和链接，它不生成任何文件，你需要把它重定向到一个输出文件里面进行查看。
使用 -E 选项进行编译：
[root@shirdrn junys]# gcc -E HelloWorld.c
或者
[root@shirdrn junys]# gcc -E HelloWorld.c > HelloWorld.txt
你可以查看HelloWorld.txt文件，预处理要执行很多的东西，共有933行，片段如下所示：
# 1 "HelloWorld.c"
# 1 "<built-in>"
# 1 "<command line>"
# 1 "HelloWorld.c"
# 1 "/usr/include/stdio.h" 1 3 4
# 28 "/usr/include/stdio.h" 3 4
# 1 "/usr/include/features.h" 1 3 4
# 328 "/usr/include/features.h" 3 4
# 1 "/usr/include/sys/cdefs.h" 1 3 4
# 324 "/usr/include/sys/cdefs.h" 3 4
# 1 "/usr/include/bits/wordsize.h" 1 3 4
# 325 "/usr/include/sys/cdefs.h" 2 3 4
# 329 "/usr/include/features.h" 2 3 4
# 351 "/usr/include/features.h" 3 4
# 1 "/usr/include/gnu/stubs.h" 1 3 4
# 1 "/usr/include/bits/wordsize.h" 1 3 4
# 5 "/usr/include/gnu/stubs.h" 2 3 4
# 1 "/usr/include/gnu/stubs-32.h" 1 3 4
# 8 "/usr/include/gnu/stubs.h" 2 3 4
# 352 "/usr/include/features.h" 2 3 4
# 29 "/usr/include/stdio.h" 2 3 4
# 1 "/usr/lib/gcc/i386-redhat-linux/4.1.2/include/stddef.h" 1 3 4
# 214 "/usr/lib/gcc/i386-redhat-linux/4.1.2/include/stddef.h" 3 4
typedef unsigned int size_t;
# 35 "/usr/include/stdio.h" 2 3 4
# 1 "/usr/include/bits/types.h" 1 3 4
# 28 "/usr/include/bits/types.h" 3 4
# 1 "/usr/include/bits/wordsize.h" 1 3 4
# 29 "/usr/include/bits/types.h" 2 3 4
# 1 "/usr/lib/gcc/i386-redhat-linux/4.1.2/include/stddef.h" 1 3 4
# 32 "/usr/include/bits/types.h" 2 3 4
typedef unsigned char __u_char;
typedef unsigned short int __u_short;
typedef unsigned int __u_int;
typedef unsigned long int __u_long;
typedef signed char __int8_t;
typedef unsigned char __uint8_t;
typedef signed short int __int16_t;
typedef unsigned short int __uint16_t;
typedef signed int __int32_t;
typedef unsigned int __uint32_t;
__extension__ typedef signed long long int __int64_t;
__extension__ typedef unsigned long long int __uint64_t;
__extension__ typedef long long int __quad_t;
__extension__ typedef unsigned long long int __u_quad_t;
# 134 "/usr/include/bits/types.h" 3 4
# 1 "/usr/include/bits/typesizes.h" 1 3 4
# 135 "/usr/include/bits/types.h" 2 3 4
__extension__ typedef __u_quad_t __dev_t;
__extension__ typedef unsigned int __uid_t;
__extension__ typedef unsigned int __gid_t;
__extension__ typedef unsigned long int __ino_t;
__extension__ typedef __u_quad_t __ino64_t;
__extension__ typedef unsigned int __mode_t;
__extension__ typedef unsigned int __nlink_t;
__extension__ typedef long int __off_t;
__extension__ typedef __quad_t __off64_t;
__extension__ typedef int __pid_t;
__extension__ typedef struct { int __val[2]; } __fsid_t;
__extension__ typedef long int __clock_t;
__extension__ typedef unsigned long int __rlim_t;
__extension__ typedef __u_quad_t __rlim64_t;
__extension__ typedef unsigned int __id_t;
__extension__ typedef long int __time_t;
__extension__ typedef unsigned int __useconds_t;
__extension__ typedef long int __suseconds_t;
__extension__ typedef int __daddr_t;
__extension__ typedef long int __swblk_t;
__extension__ typedef int __key_t;
__extension__ typedef int __clockid_t;
__extension__ typedef void * __timer_t;
__extension__ typedef long int __blksize_t;
__extension__ typedef long int __blkcnt_t;
__extension__ typedef __quad_t __blkcnt64_t;
__extension__ typedef unsigned long int __fsblkcnt_t;
__extension__ typedef __u_quad_t __fsblkcnt64_t;
__extension__ typedef unsigned long int __fsfilcnt_t;
__extension__ typedef __u_quad_t __fsfilcnt64_t;
__extension__ typedef int __ssize_t;
typedef __off64_t __loff_t;
typedef __quad_t *__qaddr_t;
typedef char *__caddr_t;
__extension__ typedef int __intptr_t;
__extension__ typedef unsigned int __socklen_t;
# 37 "/usr/include/stdio.h" 2 3 4
# 45 "/usr/include/stdio.h" 3 4
struct _IO_FILE;
typedef struct _IO_FILE FILE;
# 65 "/usr/include/stdio.h" 3 4
typedef struct _IO_FILE __FILE;
# 75 "/usr/include/stdio.h" 3 4
# 1 "/usr/include/libio.h" 1 3 4
# 32 "/usr/include/libio.h" 3 4
# 1 "/usr/include/_G_config.h" 1 3 4
# 14 "/usr/include/_G_config.h" 3 4
# 1 "/usr/lib/gcc/i386-redhat-linux/4.1.2/include/stddef.h" 1 3 4
# 326 "/usr/lib/gcc/i386-redhat-linux/4.1.2/include/stddef.h" 3 4
typedef long int wchar_t;
# 355 "/usr/lib/gcc/i386-redhat-linux/4.1.2/include/stddef.h" 3 4
typedef unsigned int wint_t;
# 15 "/usr/include/_G_config.h" 2 3 4
# 24 "/usr/include/_G_config.h" 3 4
# 1 "/usr/include/wchar.h" 1 3 4
# 48 "/usr/include/wchar.h" 3 4
# 1 "/usr/lib/gcc/i386-redhat-linux/4.1.2/include/stddef.h" 1 3 4
# 49 "/usr/include/wchar.h" 2 3 4
# 1 "/usr/include/bits/wchar.h" 1 3 4
# 51 "/usr/include/wchar.h" 2 3 4
# 76 "/usr/include/wchar.h" 3 4
typedef struct
{
int __count;
union
{
wint_t __wch;
char __wchb[4];
} __value;
} __mbstate_t;
# 25 "/usr/include/_G_config.h" 2 3 4
typedef struct
{
__off_t __pos;
__mbstate_t __state;
} _G_fpos_t;
typedef struct
{
__off64_t __pos;
__mbstate_t __state;
} _G_fpos64_t;
# 44 "/usr/include/_G_config.h" 3 4
# 1 "/usr/include/gconv.h" 1 3 4
# 28 "/usr/include/gconv.h" 3 4
# 1 "/usr/include/wchar.h" 1 3 4
# 48 "/usr/include/wchar.h" 3 4
# 1 "/usr/lib/gcc/i386-redhat-linux/4.1.2/include/stddef.h" 1 3 4
# 49 "/usr/include/wchar.h" 2 3 4
# 29 "/usr/include/gconv.h" 2 3 4
# 1 "/usr/lib/gcc/i386-redhat-linux/4.1.2/include/stddef.h" 1 3 4
# 32 "/usr/include/gconv.h" 2 3 4
enum
{
__GCONV_OK = 0,
__GCONV_NOCONV,
__GCONV_NODB,
__GCONV_NOMEM,
__GCONV_EMPTY_INPUT,
__GCONV_FULL_OUTPUT,
__GCONV_ILLEGAL_INPUT,
__GCONV_INCOMPLETE_INPUT,
__GCONV_ILLEGAL_DESCRIPTOR,
__GCONV_INTERNAL_ERROR
};
enum
{
__GCONV_IS_LAST = 0x0001,
__GCONV_IGNORE_ERRORS = 0x0002
};
struct __gconv_step;
struct __gconv_step_data;
struct __gconv_loaded_object;
struct __gconv_trans_data;
typedef int (*__gconv_fct) (struct __gconv_step *, struct __gconv_step_data *,
__const unsigned char **, __const unsigned char *,
unsigned char **, size_t *, int, int);
typedef wint_t (*__gconv_btowc_fct) (struct __gconv_step *, unsigned char);
typedef int (*__gconv_init_fct) (struct __gconv_step *);
typedef void (*__gconv_end_fct) (struct __gconv_step *);
typedef int (*__gconv_trans_fct) (struct __gconv_step *,
struct __gconv_step_data *, void *,
__const unsigned char *,
__const unsigned char **,
__const unsigned char *, unsigned char **,
size_t *);
typedef int (*__gconv_trans_context_fct) (void *, __const unsigned char *,
__const unsigned char *,
unsigned char *, unsigned char *);
typedef int (*__gconv_trans_query_fct) (__const char *, __const char ***,
size_t *);
typedef int (*__gconv_trans_init_fct) (void **, const char *);
typedef void (*__gconv_trans_end_fct) (void *);
struct __gconv_trans_data
{
__gconv_trans_fct __trans_fct;
__gconv_trans_context_fct __trans_context_fct;
__gconv_trans_end_fct __trans_end_fct;
void *__data;
struct __gconv_trans_data *__next;
};
struct __gconv_step
{
struct __gconv_loaded_object *__shlib_handle;
__const char *__modname;
int __counter;
char *__from_name;
char *__to_name;
__gconv_fct __fct;
__gconv_btowc_fct __btowc_fct;
__gconv_init_fct __init_fct;
__gconv_end_fct __end_fct;
int __min_needed_from;
int __max_needed_from;
int __min_needed_to;
int __max_needed_to;
int __stateful;
void *__data;
};
struct __gconv_step_data
{
unsigned char *__outbuf;
unsigned char *__outbufend;
int __flags;
int __invocation_counter;
int __internal_use;
__mbstate_t *__statep;
__mbstate_t __state;
struct __gconv_trans_data *__trans;
};
typedef struct __gconv_info
{
size_t __nsteps;
struct __gconv_step *__steps;
__extension__ struct __gconv_step_data __data [];
} *__gconv_t;
# 45 "/usr/include/_G_config.h" 2 3 4
typedef union
{
struct __gconv_info __cd;
struct
{
struct __gconv_info __cd;
struct __gconv_step_data __data;
} __combined;
} _G_iconv_t;
typedef int _G_int16_t __attribute__ ((__mode__ (__HI__)));
typedef int _G_int32_t __attribute__ ((__mode__ (__SI__)));
typedef unsigned int _G_uint16_t __attribute__ ((__mode__ (__HI__)));
typedef unsigned int _G_uint32_t __attribute__ ((__mode__ (__SI__)));
# 33 "/usr/include/libio.h" 2 3 4
# 53 "/usr/include/libio.h" 3 4
# 1 "/usr/lib/gcc/i386-redhat-linux/4.1.2/include/stdarg.h" 1 3 4
# 43 "/usr/lib/gcc/i386-redhat-linux/4.1.2/include/stdarg.h" 3 4
typedef __builtin_va_list __gnuc_va_list;
# 54 "/usr/include/libio.h" 2 3 4
# 167 "/usr/include/libio.h" 3 4
struct _IO_jump_t; struct _IO_FILE;
# 177 "/usr/include/libio.h" 3 4
typedef void _IO_lock_t;
struct _IO_marker {
struct _IO_marker *_next;
struct _IO_FILE *_sbuf;
int _pos;
# 200 "/usr/include/libio.h" 3 4
};
enum __codecvt_result
{
__codecvt_ok,
__codecvt_partial,
__codecvt_error,
__codecvt_noconv
};
# 268 "/usr/include/libio.h" 3 4
struct _IO_FILE {
int _flags;
char* _IO_read_ptr;
char* _IO_read_end;
char* _IO_read_base;
char* _IO_write_base;
char* _IO_write_ptr;
char* _IO_write_end;
char* _IO_buf_base;
char* _IO_buf_end;
char *_IO_save_base;
char *_IO_backup_base;
char *_IO_save_end;
struct _IO_marker *_markers;
struct _IO_FILE *_chain;
int _fileno;
int _flags2;
__off_t _old_offset;
unsigned short _cur_column;
signed char _vtable_offset;
char _shortbuf[1];
_IO_lock_t *_lock;
# 316 "/usr/include/libio.h" 3 4
__off64_t _offset;
# 325 "/usr/include/libio.h" 3 4
void *__pad1;
void *__pad2;
void *__pad3;
void *__pad4;
size_t __pad5;
int _mode;
char _unused2[15 * sizeof (int) - 4 * sizeof (void *) - sizeof (size_t)];
};
typedef struct _IO_FILE _IO_FILE;
struct _IO_FILE_plus;
extern struct _IO_FILE_plus _IO_2_1_stdin_;
extern struct _IO_FILE_plus _IO_2_1_stdout_;
extern struct _IO_FILE_plus _IO_2_1_stderr_;
# 361 "/usr/include/libio.h" 3 4
typedef __ssize_t __io_read_fn (void *__cookie, char *__buf, size_t __nbytes);
typedef __ssize_t __io_write_fn (void *__cookie, __const char *__buf,
size_t __n);
typedef int __io_seek_fn (void *__cookie, __off64_t *__pos, int __w);
typedef int __io_close_fn (void *__cookie);
# 413 "/usr/include/libio.h" 3 4
extern int __underflow (_IO_FILE *);
extern int __uflow (_IO_FILE *);
extern int __overflow (_IO_FILE *, int);
extern wint_t __wunderflow (_IO_FILE *);
extern wint_t __wuflow (_IO_FILE *);
extern wint_t __woverflow (_IO_FILE *, wint_t);
# 451 "/usr/include/libio.h" 3 4
extern int _IO_getc (_IO_FILE *__fp);
extern int _IO_putc (int __c, _IO_FILE *__fp);
extern int _IO_feof (_IO_FILE *__fp) __attribute__ ((__nothrow__));
extern int _IO_ferror (_IO_FILE *__fp) __attribute__ ((__nothrow__));
extern int _IO_peekc_locked (_IO_FILE *__fp);
extern void _IO_flockfile (_IO_FILE *) __attribute__ ((__nothrow__));
extern void _IO_funlockfile (_IO_FILE *) __attribute__ ((__nothrow__));
extern int _IO_ftrylockfile (_IO_FILE *) __attribute__ ((__nothrow__));
# 481 "/usr/include/libio.h" 3 4
extern int _IO_vfscanf (_IO_FILE * __restrict, const char * __restrict,
__gnuc_va_list, int *__restrict);
extern int _IO_vfprintf (_IO_FILE *__restrict, const char *__restrict,
__gnuc_va_list);
extern __ssize_t _IO_padn (_IO_FILE *, int, __ssize_t);
extern size_t _IO_sgetn (_IO_FILE *, void *, size_t);
extern __off64_t _IO_seekoff (_IO_FILE *, __off64_t, int, int);
extern __off64_t _IO_seekpos (_IO_FILE *, __off64_t, int);
extern void _IO_free_backup_area (_IO_FILE *) __attribute__ ((__nothrow__));
# 76 "/usr/include/stdio.h" 2 3 4
# 89 "/usr/include/stdio.h" 3 4
typedef _G_fpos_t fpos_t;
# 141 "/usr/include/stdio.h" 3 4
# 1 "/usr/include/bits/stdio_lim.h" 1 3 4
# 142 "/usr/include/stdio.h" 2 3 4
extern struct _IO_FILE *stdin;
extern struct _IO_FILE *stdout;
extern struct _IO_FILE *stderr;
extern int remove (__const char *__filename) __attribute__ ((__nothrow__));
extern int rename (__const char *__old, __const char *__new) __attribute__ ((__nothrow__));
extern FILE *tmpfile (void) ;
# 188 "/usr/include/stdio.h" 3 4
extern char *tmpnam (char *__s) __attribute__ ((__nothrow__)) ;
extern char *tmpnam_r (char *__s) __attribute__ ((__nothrow__)) ;
# 206 "/usr/include/stdio.h" 3 4
extern char *tempnam (__const char *__dir, __const char *__pfx)
__attribute__ ((__nothrow__)) __attribute__ ((__malloc__)) ;
extern int fclose (FILE *__stream);
extern int fflush (FILE *__stream);
# 231 "/usr/include/stdio.h" 3 4
extern int fflush_unlocked (FILE *__stream);
# 245 "/usr/include/stdio.h" 3 4
extern FILE *fopen (__const char *__restrict __filename,
__const char *__restrict __modes) ;
extern FILE *freopen (__const char *__restrict __filename,
__const char *__restrict __modes,
FILE *__restrict __stream) ;
# 274 "/usr/include/stdio.h" 3 4
# 285 "/usr/include/stdio.h" 3 4
extern FILE *fdopen (int __fd, __const char *__modes) __attribute__ ((__nothrow__)) ;
# 306 "/usr/include/stdio.h" 3 4
extern void setbuf (FILE *__restrict __stream, char *__restrict __buf) __attribute__ ((__nothrow__));
extern int setvbuf (FILE *__restrict __stream, char *__restrict __buf,
int __modes, size_t __n) __attribute__ ((__nothrow__));
extern void setbuffer (FILE *__restrict __stream, char *__restrict __buf,
size_t __size) __attribute__ ((__nothrow__));
extern void setlinebuf (FILE *__stream) __attribute__ ((__nothrow__));
extern int fprintf (FILE *__restrict __stream,
__const char *__restrict __format, ...);
extern int printf (__const char *__restrict __format, ...);
extern int sprintf (char *__restrict __s,
__const char *__restrict __format, ...) __attribute__ ((__nothrow__));
extern int vfprintf (FILE *__restrict __s, __const char *__restrict __format,
__gnuc_va_list __arg);
extern int vprintf (__const char *__restrict __format, __gnuc_va_list __arg);
extern int vsprintf (char *__restrict __s, __const char *__restrict __format,
__gnuc_va_list __arg) __attribute__ ((__nothrow__));
extern int snprintf (char *__restrict __s, size_t __maxlen,
__const char *__restrict __format, ...)
__attribute__ ((__nothrow__)) __attribute__ ((__format__ (__printf__, 3, 4)));
extern int vsnprintf (char *__restrict __s, size_t __maxlen,
__const char *__restrict __format, __gnuc_va_list __arg)
__attribute__ ((__nothrow__)) __attribute__ ((__format__ (__printf__, 3, 0)));
# 400 "/usr/include/stdio.h" 3 4
extern int fscanf (FILE *__restrict __stream,
__const char *__restrict __format, ...) ;
extern int scanf (__const char *__restrict __format, ...) ;
extern int sscanf (__const char *__restrict __s,
__const char *__restrict __format, ...) __attribute__ ((__nothrow__));
# 442 "/usr/include/stdio.h" 3 4
extern int fgetc (FILE *__stream);
extern int getc (FILE *__stream);
extern int getchar (void);
# 466 "/usr/include/stdio.h" 3 4
extern int getc_unlocked (FILE *__stream);
extern int getchar_unlocked (void);
# 477 "/usr/include/stdio.h" 3 4
extern int fgetc_unlocked (FILE *__stream);
extern int fputc (int __c, FILE *__stream);
extern int putc (int __c, FILE *__stream);
extern int putchar (int __c);
# 510 "/usr/include/stdio.h" 3 4
extern int fputc_unlocked (int __c, FILE *__stream);
extern int putc_unlocked (int __c, FILE *__stream);
extern int putchar_unlocked (int __c);
extern int getw (FILE *__stream);
extern int putw (int __w, FILE *__stream);
extern char *fgets (char *__restrict __s, int __n, FILE *__restrict __stream)
;
extern char *gets (char *__s) ;
# 591 "/usr/include/stdio.h" 3 4
extern int fputs (__const char *__restrict __s, FILE *__restrict __stream);
extern int puts (__const char *__s);
extern int ungetc (int __c, FILE *__stream);
extern size_t fread (void *__restrict __ptr, size_t __size,
size_t __n, FILE *__restrict __stream) ;
extern size_t fwrite (__const void *__restrict __ptr, size_t __size,
size_t __n, FILE *__restrict __s) ;
# 644 "/usr/include/stdio.h" 3 4
extern size_t fread_unlocked (void *__restrict __ptr, size_t __size,
size_t __n, FILE *__restrict __stream) ;
extern size_t fwrite_unlocked (__const void *__restrict __ptr, size_t __size,
size_t __n, FILE *__restrict __stream) ;
extern int fseek (FILE *__stream, long int __off, int __whence);
extern long int ftell (FILE *__stream) ;
extern void rewind (FILE *__stream);
# 680 "/usr/include/stdio.h" 3 4
extern int fseeko (FILE *__stream, __off_t __off, int __whence);
extern __off_t ftello (FILE *__stream) ;
# 699 "/usr/include/stdio.h" 3 4
extern int fgetpos (FILE *__restrict __stream, fpos_t *__restrict __pos);
extern int fsetpos (FILE *__stream, __const fpos_t *__pos);
# 722 "/usr/include/stdio.h" 3 4
# 731 "/usr/include/stdio.h" 3 4
extern void clearerr (FILE *__stream) __attribute__ ((__nothrow__));
extern int feof (FILE *__stream) __attribute__ ((__nothrow__)) ;
extern int ferror (FILE *__stream) __attribute__ ((__nothrow__)) ;
extern void clearerr_unlocked (FILE *__stream) __attribute__ ((__nothrow__));
extern int feof_unlocked (FILE *__stream) __attribute__ ((__nothrow__)) ;
extern int ferror_unlocked (FILE *__stream) __attribute__ ((__nothrow__)) ;
extern void perror (__const char *__s);
# 1 "/usr/include/bits/sys_errlist.h" 1 3 4
# 27 "/usr/include/bits/sys_errlist.h" 3 4
extern int sys_nerr;
extern __const char *__const sys_errlist[];
# 761 "/usr/include/stdio.h" 2 3 4
extern int fileno (FILE *__stream) __attribute__ ((__nothrow__)) ;
extern int fileno_unlocked (FILE *__stream) __attribute__ ((__nothrow__)) ;
# 780 "/usr/include/stdio.h" 3 4
extern FILE *popen (__const char *__command, __const char *__modes) ;
extern int pclose (FILE *__stream);
extern char *ctermid (char *__s) __attribute__ ((__nothrow__));
# 820 "/usr/include/stdio.h" 3 4
extern void flockfile (FILE *__stream) __attribute__ ((__nothrow__));
extern int ftrylockfile (FILE *__stream) __attribute__ ((__nothrow__)) ;
extern void funlockfile (FILE *__stream) __attribute__ ((__nothrow__));
# 850 "/usr/include/stdio.h" 3 4
# 2 "HelloWorld.c" 2
int main()
{
printf("Hello,the world!/n");
return 0;
}
7、-pipe 选项
使用管道代替编译中临时文件。
使用-pipe选项编译运行：
[root@shirdrn junys]# gcc -pipe -o HelloWorld HelloWorld.c
[root@shirdrn junys]# ./HelloWorld
Hello,the world!
该选项，使用管道代替临时文件，表面上，并没有看出有什么特别的。
- GCC __typeof__ __extension__
- __typeof__
- 关键字 __typeof__
- __extension__ typedef int __ssize_t;是什么意思
- __extension__ typedef int __ssize_t;是什么意思
- __thread 和 __typeof__关键字
- __thread 和 __typeof__关键字
- typeof(),__typeof__(),__typeof()
- __thread 和 __typeof__关键字
- __thread 和 __typeof__关键字
- __thread 和 __typeof__关键字
- __typeof__ / __attribute__((__section__ / __attrubte__ ((packed))
- __thread, __typeof__与逗号表达式
- __thread, __typeof__与逗号表达式
- gcc/
- gcc
- gcc
- gcc
- Python、Unicode和中文[转]
- 片内RAM的四种工作模式
- 带单位、验证码文本框
- DateTime格式化
- 一次使用duplicate创建测试数据库的过程
- GCC __typeof__ __extension__
- 怎样在内存缓冲中画图 转载 原作者 相生昌
- 企业整站优化的一些技巧
- SharedPreferences的使用
- C++枚举类型
- Android平台中Wifi的初始化
- Wget与crontab组合定时任务的用法……
- error LNK2001: 无法解析的外部符号
- ubuntu下获取命令的源代码
