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Add non-macro stdin/stdout/stderr too.

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Various C and C++ standards explicitly say that stdin/stdout/stderr
should be macros, but glibc makes them global variables too. This
means it's possible to write code that uses those names as locals,
but that code (toybox being an example) won't build on bionic.

If we'd done this earlier, we could have hidden __sF for LP64, but
it's too late now.

Change-Id: I90cf8c73f52b66e1760b8fa2e135b9f9f9651230
This commit is contained in:
Elliott Hughes 2014-11-14 14:42:59 -08:00
parent 898aab282c
commit 168667c972
3 changed files with 13 additions and 9 deletions
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13
libc/include/stdio.h
View File

@ -146,7 +146,16 @@ typedef struct __sFILE {
fpos_t _offset; /* current lseek offset */
} FILE;
/* Legacy BSD implementation of stdin/stdout/stderr. */
extern FILE __sF[];
/* More obvious implementation. */
extern FILE* stdin;
extern FILE* stdout;
extern FILE* stderr;
/* C99 and earlier plus current C++ standards say these must be macros. */
#define stdin stdin
#define stdout stdout
#define stderr stderr
#define __SLBF 0x0001 /* line buffered */
#define __SNBF 0x0002 /* unbuffered */
@ -209,10 +218,6 @@ extern FILE __sF[];
#define SEEK_END 2 /* set file offset to EOF plus offset */
#endif
#define stdin (&__sF[0])
#define stdout (&__sF[1])
#define stderr (&__sF[2])
/*
* Functions defined in ANSI C standard.
*/

4
libc/stdio/fileext.h
View File

@ -43,10 +43,6 @@ struct __sfileext {
pthread_mutex_t _lock; /* file lock */
};
__LIBC_HIDDEN__ extern struct __sfileext __sFext[3];
#define _FILEEXT_INITIALIZER {{NULL,0},{0},PTHREAD_RECURSIVE_MUTEX_INITIALIZER}
#define _EXT(fp) ((struct __sfileext *)((fp)->_ext._base))
#define _UB(fp) _EXT(fp)->_ub
#define _FLOCK(fp) _EXT(fp)->_lock

5
libc/stdio/findfp.c
View File

@ -59,12 +59,15 @@ static struct glue uglue = { 0, FOPEN_MAX - 3, usual };
static struct glue *lastglue = &uglue;
_THREAD_PRIVATE_MUTEX(__sfp_mutex);
struct __sfileext __sFext[3];
static struct __sfileext __sFext[3];
FILE __sF[3] = {
std(__SRD, STDIN_FILENO), /* stdin */
std(__SWR, STDOUT_FILENO), /* stdout */
std(__SWR|__SNBF, STDERR_FILENO) /* stderr */
};
FILE* stdin = &__sF[0];
FILE* stdout = &__sF[1];
FILE* stderr = &__sF[2];
struct glue __sglue = { &uglue, 3, __sF };
static struct glue *