On Tue, 6 Dec 2016 at 17:59, Jonathan Wakely wrote:
> >Subject: [PATCH 3/3] Enable libstdc++ compilation in AVR targets
> >
> >Enable libstdc++ compilation in AVR targets with AVR-Libc. Most
> >floating point math functions are already defined in AVR-Libc, so
> >defines are in place to avoid multiple definition of these functions.
>
> I've committed this one too.
Hi Felipe,
Back in 2006 we committed a patch from you that made this change:
--- a/libstdc++-v3/crossconfig.m4
+++ b/libstdc++-v3/crossconfig.m4
@@ -9,6 +9,32 @@ case "${host}" in
# This is a freestanding configuration; there is nothing to do here.
;;
+ avr*-*-*)
+ AC_DEFINE(HAVE_ACOSF)
+ AC_DEFINE(HAVE_ASINF)
+ AC_DEFINE(HAVE_ATAN2F)
+ AC_DEFINE(HAVE_ATANF)
+ AC_DEFINE(HAVE_CEILF)
+ AC_DEFINE(HAVE_COSF)
+ AC_DEFINE(HAVE_COSHF)
+ AC_DEFINE(HAVE_EXPF)
+ AC_DEFINE(HAVE_FABSF)
+ AC_DEFINE(HAVE_FLOORF)
+ AC_DEFINE(HAVE_FMODF)
+ AC_DEFINE(HAVE_FREXPF)
+ AC_DEFINE(HAVE_SQRTF)
+ AC_DEFINE(HAVE_HYPOTF)
+ AC_DEFINE(HAVE_LDEXPF)
+ AC_DEFINE(HAVE_LOG10F)
+ AC_DEFINE(HAVE_LOGF)
+ AC_DEFINE(HAVE_MODFF)
+ AC_DEFINE(HAVE_POWF)
+ AC_DEFINE(HAVE_SINF)
+ AC_DEFINE(HAVE_SINHF)
+ AC_DEFINE(HAVE_TANF)
+ AC_DEFINE(HAVE_TANHF)
+ ;;
+
mips*-sde-elf*)
# These definitions are for the SDE C library rather than newlib.
SECTION_FLAGS='-ffunction-sections -fdata-sections'
I'm testing a change today which causes a build failure on avr,
because of your config change.
I've filed https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111639 about
this, could you take a look please?
You said that AVR has those math functions, so we don't need to define
them in libstdc++-v3/src/c++98/math_stubs_float.cc but I don't think
that's true. It doesn't have them, it has macros like this:
extern double acos(double __x) __ATTR_CONST__;
#define acosf acos /**< The alias for acos(). */
That does indeed cause build failures in math_stubs_float.cc, but not
because of duplicate definitions of acosf etc.
And the macro definitions are not acceptable definitions of those
functions for a C++ library.
I've proposed a fix in the bug report.
