crt/stdio/mingw_pformat.c: Make the %e specifier compliant to C99.
Remove the hacks to mimic old MS behavior and hardcode the minimum
number of digits of the exponent to 2, as required by C99 and POSIX.
If the __USE_MINGW_ANSI_STDIO macro is not defined, the user will
be calling stdio functions from MSVCRT which this change will not
interfere with.
Signed-off-by: Liu Hao <lh_mouse@126.com>
(cherry picked from commit bcf1f29d6dc80b6025b416bef104d2314fa9be57)
Signed-off-by: Jonathan Yong <10walls@gmail.com>
diff --git a/mingw-w64-crt/stdio/mingw_pformat.c b/mingw-w64-crt/stdio/mingw_pformat.c
index c770101..1500aa3 100644
--- a/mingw-w64-crt/stdio/mingw_pformat.c
+++ b/mingw-w64-crt/stdio/mingw_pformat.c
@@ -182,61 +182,6 @@
*/
#define PFORMAT_INFNAN -32768
-#ifdef _WIN32
-/*
- * The Microsoft standard for printing `%e' format exponents is
- * with a minimum of three digits, unless explicitly set otherwise,
- * by a prior invocation of the `_set_output_format()' function.
- *
- * The following macro allows us to replicate this behaviour.
- */
-# define PFORMAT_MINEXP __pformat_exponent_digits()
- /*
- * However, this feature is unsupported for versions of the
- * MSVC runtime library prior to msvcr80.dll, and by default,
- * MinGW uses an earlier version, (equivalent to msvcr60.dll),
- * for which `_TWO_DIGIT_EXPONENT' will be undefined.
- */
-# ifndef _TWO_DIGIT_EXPONENT
- /*
- * This hack works around the lack of the `_set_output_format()'
- * feature, when supporting versions of the MSVC runtime library
- * prior to msvcr80.dll; it simply enforces Microsoft's original
- * convention, for all cases where the feature is unsupported.
- */
-# define _get_output_format() 0
-# define _TWO_DIGIT_EXPONENT 1
-# endif
-/*
- * Irrespective of the MSVCRT version supported, *we* will add
- * an additional capability, through the following inline function,
- * which will allow the user to choose his own preferred default
- * for `PRINTF_EXPONENT_DIGITS', through the simple expedient
- * of defining it as an environment variable.
- */
-static
-int __pformat_exponent_digits( void )
-{
- /* Calling getenv is expensive; only do it once and cache the result. */
- static int two_exp_digits_env = -1;
- if (two_exp_digits_env == -1) {
- const char *exponent_digits_env = getenv( "PRINTF_EXPONENT_DIGITS" );
- two_exp_digits_env = exponent_digits_env != NULL
- && (unsigned)(*exponent_digits_env - '0') < 3;
- }
- return (two_exp_digits_env || (_get_output_format() & _TWO_DIGIT_EXPONENT))
- ? 2
- : 3
- ;
-}
-#else
-/*
- * When we don't care to mimic Microsoft's standard behaviour,
- * we adopt the C99/POSIX standard of two digit exponents.
- */
-# define PFORMAT_MINEXP 2
-#endif
-
typedef union
{
/* A data type agnostic representation,
@@ -1555,9 +1500,11 @@
exp_width++;
/* Ensure that this is at least as many as the standard requirement.
+ * The C99 standard requires the expenent to contain at least two
+ * digits, unless specified explicitly otherwise.
*/
if (stream->expmin == -1)
- stream->expmin = PFORMAT_MINEXP;
+ stream->expmin = 2;
if( exp_width < stream->expmin )
exp_width = stream->expmin;
