https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95592
Bug ID: 95592
Summary: Collision with struct _Cosh when Cross compiling
libstdc++
Product: gcc
Version: 8.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: kevin at arilabs dot net
Target Milestone: ---
I am cross compiling gcc 8.3.0 for QNX 6.6. While doing so,
libstdc++-v3/include/bits/valarray_after.h was having trouble with "struct
_Cosh" defined in valarray_before.h because it was colliding with the function
_Cosh() is defined in one of the target OS's headers.
Specifically it was having trouble with (around line 445 of valarray_after.h):
_DEFINE_EXPR_UNARY_FUNCTION(cosh, _Cosh)
The compiler was using the function declaration of _Cosh instead of struct
_Cosh.
There were other _DEFINE_EXPR_UNARY_FUNCTION that had the same issue (I don't
remember which ones as I focused on _Cosh).
Below is a patch to valarray_after.h that fixes the issue. I'm pretty sure QNX
may be the only target OS with this problem, so I am content if this doesn't
make it in gcc, but thought that perhaps removing ambiguity from the preceding
template definitions wouldn't be bad.
I took a look at gcc 9 and 10 code base and the issue appears to exist there as
well.
Thanks
Kevin
Index: libstdc++-v3/include/bits/valarray_after.h
===================================================================
--- libstdc++-v3/include/bits/valarray_after.h (revision 1469)
+++ libstdc++-v3/include/bits/valarray_after.h (working copy)
@@ -422,20 +422,20 @@
#define _DEFINE_EXPR_UNARY_FUNCTION(_Name, _UName) \
template<class _Dom> \
- inline _Expr<_UnClos<_UName, _Expr, _Dom>, \
+ inline _Expr<_UnClos<struct _UName, _Expr, _Dom>,
\
typename _Dom::value_type> \
_Name(const _Expr<_Dom, typename _Dom::value_type>& __e) \
{ \
typedef typename _Dom::value_type _Tp; \
- typedef _UnClos<_UName, _Expr, _Dom> _Closure; \
+ typedef _UnClos<struct _UName, _Expr, _Dom> _Closure;
\
return _Expr<_Closure, _Tp>(_Closure(__e())); \
} \
\
template<typename _Tp> \
- inline _Expr<_UnClos<_UName, _ValArray, _Tp>, _Tp> \
+ inline _Expr<_UnClos<struct _UName, _ValArray, _Tp>, _Tp>
\
_Name(const valarray<_Tp>& __v) \
{ \
- typedef _UnClos<_UName, _ValArray, _Tp> _Closure; \
+ typedef _UnClos<struct _UName, _ValArray, _Tp> _Closure;
\
return _Expr<_Closure, _Tp>(_Closure(__v)); \
}
