X-Authentication-Warning:	delorie.com: mail set sender to djgpp-workers-bounces using -f
Date:	Sat, 25 Oct 2003 21:09:55 +0100
From:	"Richard Dawe" <rich AT phekda DOT freeserve DOT co DOT uk>
Sender:	rich AT phekda DOT freeserve DOT co DOT uk
To:	djgpp-workers AT delorie DOT com, max_payne AT hotpop DOT com
X-Mailer:	Emacs 21.3.50 (via feedmail 8.3.emacs20_6 I) and Blat ver 1.8.6
Subject:	math.h: Better C99 and C++ compliance [PATCH]
Message-Id:	<E1ADUYm-0001QK-00@phekda.freeserve.co.uk>
Reply-To:	djgpp-workers AT delorie DOT com

Hello.

math.h needs some work to comply with the C99 and C++ standards.

For C99 we need to move definitions from the non-standard
section into the C99 section.

For C++ we need to make some of the definitions available
even when -ansi is used. This is because std::cos, etc. are actually
overloaded functions with versions available for float, double
and long double. libstdc++ provides these by calling ::cosf, etc.

So now there are two C99 sections: one for C99 stuff that should
be able for C++ even when -ansi was used to compile;
one for normal C99 stuff.

Without this patch, the following C++ test program fails to build:

    #include <cmath>
    int main (void) { return 0; }

when built with:

    gcc -ansi -o foo foo.c

You get errors like this:

    In file included from dashansi.cpp:1:
    c:/djgpp/lang/cxx/3.23/cmath: In function `float std::acos(float)':
    c:/djgpp/lang/cxx/3.23/cmath:99: `::acosf' undeclared (first use here)

For more information, see the text below table 80 in the ISO C++ standard.
It lists the functions that are overloaded there. (Basically the ones
that I have moved.)

I tested with stdlibc++ from gcc 3.2.1, but it still happens
with gcc 3.3.2. (See today's messages in comp.os.msdos.djgpp.)

OK to commit?

Bye, Rich =]

Index: include/math.h
===================================================================
RCS file: /cvs/djgpp/djgpp/include/math.h,v
retrieving revision 1.10
diff -p -u -3 -r1.10 math.h
--- include/math.h	25 Oct 2003 11:22:53 -0000	1.10
+++ include/math.h	25 Oct 2003 19:50:55 -0000
@@ -42,6 +42,49 @@ double	sqrt(double _x);
 double	tan(double _x);
 double	tanh(double _x);
 
+/* The C++ standard has overloaded versions of cos, etc. for floats
+ * and long doubles. libstdc++ calls the C99-standardised float
+ * and long double versions of cos, etc. in the global namespace
+ * to provide the overloaded versions. So we place the float
+ * and long double versions in the global namespace for C++
+ * even when __STRICT_ANSI__ is defined.
+ */
+#if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L) \
+  || !defined(__STRICT_ANSI__) \
+  || defined(__cplusplus)
+
+long double modfl(long double _x, long double *_pint);
+
+/* These are in libm.a (Cygnus).  You must link -lm to get these */
+/* See libm/math.h for comments */
+
+extern float acosf(float);
+extern float asinf(float);
+extern float atanf(float);
+extern float atan2f(float, float);
+extern float cosf(float);
+extern float sinf(float);
+extern float tanf(float);
+extern float coshf(float);
+extern float sinhf(float);
+extern float tanhf(float);
+extern float expf(float);
+extern float frexpf(float, int *);
+extern float ldexpf(float, int);
+extern float logf(float);
+extern float log10f(float);
+extern float modff(float, float *);
+extern float powf(float, float);
+extern float sqrtf(float);
+extern float ceilf(float);
+extern float fabsf(float);
+extern float floorf(float);
+extern float fmodf(float, float);
+
+/* End libm.a. */
+
+#endif
+
 #if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L) \
   || !defined(__STRICT_ANSI__)
 
@@ -82,6 +125,50 @@ double		nan(const char *);
 float		nanf(const char *);
 long double	nanl(const char *);
 
+double	acosh(double);
+double	asinh(double);
+double	atanh(double);
+double	cbrt(double);
+double	exp2(double _x);
+double	expm1(double);
+double	hypot(double, double);
+double	log1p(double);
+double	log2(double _x);
+
+/* These are in libm.a (Cygnus).  You must link -lm to get these */
+/* See libm/math.h for comments */
+
+extern double erf(double);
+extern double erfc(double);
+extern double lgamma(double);
+extern double logb(double);
+extern double nextafter(double, double);
+extern double remainder(double, double);
+extern double copysign(double, double);
+extern int ilogb(double);
+extern double rint(double);
+extern double scalbn(double, int);
+extern float erff(float);
+extern float erfcf(float);
+extern float hypotf(float, float);
+extern float lgammaf(float);
+extern float acoshf(float);
+extern float asinhf(float);
+extern float atanhf(float);
+extern float cbrtf(float);
+extern float logbf(float);
+extern float nextafterf(float, float);
+extern float remainderf(float, float);
+extern float scalbf(float, float);
+extern float copysignf(float, float);
+extern int ilogbf(float);
+extern float rintf(float);
+extern float scalbnf(float, int);
+extern float expm1f(float);
+extern float log1pf(float);
+
+/* End libm.a. */
+
 #endif /* (__STDC_VERSION__ >= 199901L) || !__STRICT_ANSI__ */
   
 #ifndef __STRICT_ANSI__
@@ -104,17 +191,7 @@ long double	nanl(const char *);
 #define PI		M_PI
 #define PI2		M_PI_2
 
-double	acosh(double);
-double	asinh(double);
-double	atanh(double);
-double	cbrt(double);
 double	exp10(double _x);
-double	exp2(double _x);
-double	expm1(double);
-double	hypot(double, double);
-double	log1p(double);
-double	log2(double _x);
-long double modfl(long double _x, long double *_pint);
 double	pow10(double _x);
 double	pow2(double _x);
 double	powi(double, int);
@@ -134,84 +211,34 @@ struct exception {
 };
 #endif
 
-extern double erf(double);
-extern double erfc(double);
 extern double gamma(double);
 extern int finite(double);
 extern double j0(double);
 extern double j1(double);
 extern double jn(int, double);
-extern double lgamma(double);
 extern double y0(double);
 extern double y1(double);
 extern double yn(int, double);
-extern double logb(double);
-extern double nextafter(double, double);
-extern double remainder(double, double);
 extern double scalb(double, double);
 #ifndef __cplusplus
 extern int matherr(struct exception *);
 #endif
 extern double significand(double);
-extern double copysign(double, double);
-extern int ilogb(double);
-extern double rint(double);
-extern double scalbn(double, int);
 extern double drem(double, double);
 extern double gamma_r(double, int *);
 extern double lgamma_r(double, int *);
-extern float acosf(float);
-extern float asinf(float);
-extern float atanf(float);
-extern float atan2f(float, float);
-extern float cosf(float);
-extern float sinf(float);
-extern float tanf(float);
-extern float coshf(float);
-extern float sinhf(float);
-extern float tanhf(float);
-extern float expf(float);
-extern float frexpf(float, int *);
-extern float ldexpf(float, int);
-extern float logf(float);
-extern float log10f(float);
-extern float modff(float, float *);
-extern float powf(float, float);
-extern float sqrtf(float);
-extern float ceilf(float);
-extern float fabsf(float);
-extern float floorf(float);
-extern float fmodf(float, float);
-extern float erff(float);
-extern float erfcf(float);
 extern float gammaf(float);
-extern float hypotf(float, float);
 extern int isinff(float);
 extern int isnanf(float);
 extern int finitef(float);
 extern float j0f(float);
 extern float j1f(float);
 extern float jnf(int, float);
-extern float lgammaf(float);
 extern float y0f(float);
 extern float y1f(float);
 extern float ynf(int, float);
-extern float acoshf(float);
-extern float asinhf(float);
-extern float atanhf(float);
-extern float cbrtf(float);
-extern float logbf(float);
-extern float nextafterf(float, float);
-extern float remainderf(float, float);
-extern float scalbf(float, float);
 extern float significandf(float);
-extern float copysignf(float, float);
-extern int ilogbf(float);
-extern float rintf(float);
-extern float scalbnf(float, int);
 extern float dremf(float, float);
-extern float expm1f(float);
-extern float log1pf(float);
 extern float gammaf_r(float, int *);
 extern float lgammaf_r(float, int *);
 

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