From 7224e32d7be41b39358defc0e33d2737307aa06a Mon Sep 17 00:00:00 2001 From: Carlos O'Donell Date: Mon, 8 May 2017 16:11:45 -0400 Subject: [PATCH] vfprintf.c: Refactor magic number 32 into EXTSIZ. The magic number 32 is used everywhere as extra size to use when doing certain operations. This commit refactors that into a macro so you can change this value if you're debugging something in a local build. --- ChangeLog | 6 +++++ stdio-common/vfprintf.c | 52 +++++++++++++++++++++-------------------- 2 files changed, 33 insertions(+), 25 deletions(-) diff --git a/ChangeLog b/ChangeLog index 49378f6609..768274fe9e 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,9 @@ +2017-05-08 Carlos O'Donell + + * stdio-common/vfprintf.c (EXTSIZ): Define. + (vfprintf): Use EXTSIZ. + (printf_positional): Likewise. + 2017-05-08 Joseph Myers * sysdeps/unix/sysv/linux/kernel-features.h diff --git a/stdio-common/vfprintf.c b/stdio-common/vfprintf.c index 54b1ba2ac8..2cf7c8aa0b 100644 --- a/stdio-common/vfprintf.c +++ b/stdio-common/vfprintf.c @@ -45,6 +45,10 @@ #define va_list _IO_va_list #undef BUFSIZ #define BUFSIZ _IO_BUFSIZ +/* In some cases we need extra space for all the output which is not + counted in the width of the string. We assume 32 characters is + enough. */ +#define EXTSIZ 32 #define ARGCHECK(S, Format) \ do \ { \ @@ -1456,20 +1460,19 @@ vfprintf (FILE *s, const CHAR_T *format, va_list ap) left = 1; } - if (__glibc_unlikely (width >= INT_MAX / sizeof (CHAR_T) - 32)) + if (__glibc_unlikely (width >= INT_MAX / sizeof (CHAR_T) - EXTSIZ)) { __set_errno (EOVERFLOW); done = -1; goto all_done; } - if (width >= WORK_BUFFER_SIZE - 32) + if (width >= WORK_BUFFER_SIZE - EXTSIZ) { - /* We have to use a special buffer. The "32" is just a safe - bet for all the output which is not counted in the width. */ - size_t needed = ((size_t) width + 32) * sizeof (CHAR_T); + /* We have to use a special buffer. */ + size_t needed = ((size_t) width + EXTSIZ) * sizeof (CHAR_T); if (__libc_use_alloca (needed)) - workend = (CHAR_T *) alloca (needed) + width + 32; + workend = (CHAR_T *) alloca (needed) + width + EXTSIZ; else { workstart = (CHAR_T *) malloc (needed); @@ -1478,7 +1481,7 @@ vfprintf (FILE *s, const CHAR_T *format, va_list ap) done = -1; goto all_done; } - workend = workstart + width + 32; + workend = workstart + width + EXTSIZ; } } } @@ -1489,20 +1492,19 @@ vfprintf (FILE *s, const CHAR_T *format, va_list ap) width = read_int (&f); if (__glibc_unlikely (width == -1 - || width >= INT_MAX / sizeof (CHAR_T) - 32)) + || width >= INT_MAX / sizeof (CHAR_T) - EXTSIZ)) { __set_errno (EOVERFLOW); done = -1; goto all_done; } - if (width >= WORK_BUFFER_SIZE - 32) + if (width >= WORK_BUFFER_SIZE - EXTSIZ) { - /* We have to use a special buffer. The "32" is just a safe - bet for all the output which is not counted in the width. */ - size_t needed = ((size_t) width + 32) * sizeof (CHAR_T); + /* We have to use a special buffer. */ + size_t needed = ((size_t) width + EXTSIZ) * sizeof (CHAR_T); if (__libc_use_alloca (needed)) - workend = (CHAR_T *) alloca (needed) + width + 32; + workend = (CHAR_T *) alloca (needed) + width + EXTSIZ; else { workstart = (CHAR_T *) malloc (needed); @@ -1511,7 +1513,7 @@ vfprintf (FILE *s, const CHAR_T *format, va_list ap) done = -1; goto all_done; } - workend = workstart + width + 32; + workend = workstart + width + EXTSIZ; } } if (*f == L_('$')) @@ -1562,23 +1564,23 @@ vfprintf (FILE *s, const CHAR_T *format, va_list ap) } else prec = 0; - if (prec > width && prec > WORK_BUFFER_SIZE - 32) + if (prec > width && prec > WORK_BUFFER_SIZE - EXTSIZ) { /* Deallocate any previously allocated buffer because it is too small. */ if (__glibc_unlikely (workstart != NULL)) free (workstart); workstart = NULL; - if (__glibc_unlikely (prec >= INT_MAX / sizeof (CHAR_T) - 32)) + if (__glibc_unlikely (prec >= INT_MAX / sizeof (CHAR_T) - EXTSIZ)) { __set_errno (EOVERFLOW); done = -1; goto all_done; } - size_t needed = ((size_t) prec + 32) * sizeof (CHAR_T); + size_t needed = ((size_t) prec + EXTSIZ) * sizeof (CHAR_T); if (__libc_use_alloca (needed)) - workend = (CHAR_T *) alloca (needed) + prec + 32; + workend = (CHAR_T *) alloca (needed) + prec + EXTSIZ; else { workstart = (CHAR_T *) malloc (needed); @@ -1587,7 +1589,7 @@ vfprintf (FILE *s, const CHAR_T *format, va_list ap) done = -1; goto all_done; } - workend = workstart + prec + 32; + workend = workstart + prec + EXTSIZ; } } JUMP (*f, step2_jumps); @@ -1964,23 +1966,23 @@ printf_positional (_IO_FILE *s, const CHAR_T *format, int readonly_format, } /* Maybe the buffer is too small. */ - if (MAX (prec, width) + 32 > WORK_BUFFER_SIZE) + if (MAX (prec, width) + EXTSIZ > WORK_BUFFER_SIZE) { - if (__libc_use_alloca ((MAX (prec, width) + 32) + if (__libc_use_alloca ((MAX (prec, width) + EXTSIZ) * sizeof (CHAR_T))) - workend = ((CHAR_T *) alloca ((MAX (prec, width) + 32) + workend = ((CHAR_T *) alloca ((MAX (prec, width) + EXTSIZ) * sizeof (CHAR_T)) - + (MAX (prec, width) + 32)); + + (MAX (prec, width) + EXTSIZ)); else { - workstart = (CHAR_T *) malloc ((MAX (prec, width) + 32) + workstart = (CHAR_T *) malloc ((MAX (prec, width) + EXTSIZ) * sizeof (CHAR_T)); if (workstart == NULL) { done = -1; goto all_done; } - workend = workstart + (MAX (prec, width) + 32); + workend = workstart + (MAX (prec, width) + EXTSIZ); } }