[libcxx-commits] [PATCH] D131929: [libcxx] Resolve warnings for Wimplicit-float-conversion, Wmacro-redefined, Wzero-as-null-pointer-constant, Wsign-conversion

[Dominic Chen via Phabricator via libcxx-commits]

ddcc marked an inline comment as not done.
ddcc added a comment.

In D131929#3727098 <https://reviews.llvm.org/D131929#3727098>, @ldionne wrote:

> Thanks for the patch!
>
>> These warnings should be enabled in the test suite to avoid regressions.
>
> @ddcc You can do that by adding them in `libcxx/utils/libcxx/test/params.py`.

Will do.



================
Comment at: libcxx/include/atomic:2694
 
+#undef ATOMIC_FLAG_INIT
 #define ATOMIC_FLAG_INIT {false}
----------------
ldionne wrote:
> Is this because `ATOMIC_FLAG_INIT` was already defined by the C Library?
Yeah, not sure whether we want to unconditionally undef or do ifdef here.


================
Comment at: libcxx/include/cmath:534
 inline _LIBCPP_INLINE_VISIBILITY float       hypot(       float __x,       float __y,       float __z ) { return sqrt(__x*__x + __y*__y + __z*__z); }
-inline _LIBCPP_INLINE_VISIBILITY double      hypot(      double __x,      double __y,      double __z ) { return sqrt(__x*__x + __y*__y + __z*__z); }
-inline _LIBCPP_INLINE_VISIBILITY long double hypot( long double __x, long double __y, long double __z ) { return sqrt(__x*__x + __y*__y + __z*__z); }
+inline _LIBCPP_INLINE_VISIBILITY double      hypot(      double __x,      double __y,      double __z ) { return sqrtf(__x*__x + __y*__y + __z*__z); }
+inline _LIBCPP_INLINE_VISIBILITY long double hypot( long double __x, long double __y, long double __z ) { return sqrtl(__x*__x + __y*__y + __z*__z); }
----------------
philnik wrote:
> What exactly is the problem here? `sqrt` has overloads for `float`, `double` and `long double`.
```
warning: implicit conversion loses floating-point precision: 'double' to 'float' [-Wimplicit-float-conversion]
inline _LIBCPP_INLINE_VISIBILITY float       hypot(       float x,       float y,       float z ) { return sqrt(x*x + y*y + z*z); }
                                                                                                    ~~~~~~ ^~~~~~~~~~~~~~~~~~~~~
```


================
Comment at: libcxx/include/string_view:288
     typedef ptrdiff_t                                  difference_type;
-    static _LIBCPP_CONSTEXPR const size_type npos = -1; // size_type(-1);
+    static _LIBCPP_CONSTEXPR const size_type npos = ~static_cast<size_type>(0U); // size_type(-1);
 
----------------
philnik wrote:
> Maybe use numeric_limits here instead?
Will do.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D131929/new/

https://reviews.llvm.org/D131929