[libc++] Replace uses of _LIBCPP_ALWAYS_INLINE by _LIBCPP_INLINE_VISI…

…BILITY

Summary:
We never actually mean to always inline a function -- all the uses of
the macro I could find are actually attempts to control the visibility
of symbols. This is better described by _LIBCPP_INLINE_VISIBILITY, which
is actually always defined the same.

This change is orthogonal to the decision of what we're actually going
to do with _LIBCPP_INLINE_VISIBILITY -- it just simplifies things by
having one canonical way of doing things.

Reviewers: EricWF

Subscribers: christof, llvm-commits, dexonsmith, erikvanderpoel, mclow.lists

Differential Revision: https://reviews.llvm.org/D48892

llvm-svn: 336369

libcxx/docs/DesignDocs/VisibilityMacros.rst

@@ -41,10 +41,10 @@ Visibility Macros
   library and has an empty definition otherwise.
 
 **_LIBCPP_INLINE_VISIBILITY**
-  Mark a function as hidden and force inlining whenever possible.
-
-**_LIBCPP_ALWAYS_INLINE**
-  A synonym for `_LIBCPP_INLINE_VISIBILITY`
+  Mark a function as not being part of the ABI of any final linked image that
+  uses it, and also as being internal to each TU that uses that function. In
+  other words, the address of a function marked with this attribute is not
+  guaranteed to be the same across translation units.
 
 **_LIBCPP_TYPE_VIS**
   Mark a type's typeinfo, vtable and members as having default visibility.

libcxx/include/__bsd_locale_fallbacks.h

@@ -24,80 +24,80 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-inline _LIBCPP_ALWAYS_INLINE
+inline _LIBCPP_INLINE_VISIBILITY
 decltype(MB_CUR_MAX) __libcpp_mb_cur_max_l(locale_t __l)
 {
     __libcpp_locale_guard __current(__l);
     return MB_CUR_MAX;
 }
 
-inline _LIBCPP_ALWAYS_INLINE
+inline _LIBCPP_INLINE_VISIBILITY
 wint_t __libcpp_btowc_l(int __c, locale_t __l)
 {
     __libcpp_locale_guard __current(__l);
     return btowc(__c);
 }
 
-inline _LIBCPP_ALWAYS_INLINE
+inline _LIBCPP_INLINE_VISIBILITY
 int __libcpp_wctob_l(wint_t __c, locale_t __l)
 {
     __libcpp_locale_guard __current(__l);
     return wctob(__c);
 }
 
-inline _LIBCPP_ALWAYS_INLINE
+inline _LIBCPP_INLINE_VISIBILITY
 size_t __libcpp_wcsnrtombs_l(char *__dest, const wchar_t **__src, size_t __nwc,
                          size_t __len, mbstate_t *__ps, locale_t __l)
 {
     __libcpp_locale_guard __current(__l);
     return wcsnrtombs(__dest, __src, __nwc, __len, __ps);
 }
 
-inline _LIBCPP_ALWAYS_INLINE
+inline _LIBCPP_INLINE_VISIBILITY
 size_t __libcpp_wcrtomb_l(char *__s, wchar_t __wc, mbstate_t *__ps, locale_t __l)
 {
     __libcpp_locale_guard __current(__l);
     return wcrtomb(__s, __wc, __ps);
 }
 
-inline _LIBCPP_ALWAYS_INLINE
+inline _LIBCPP_INLINE_VISIBILITY
 size_t __libcpp_mbsnrtowcs_l(wchar_t * __dest, const char **__src, size_t __nms,
                       size_t __len, mbstate_t *__ps, locale_t __l)
 {
     __libcpp_locale_guard __current(__l);
     return mbsnrtowcs(__dest, __src, __nms, __len, __ps);
 }
 
-inline _LIBCPP_ALWAYS_INLINE
+inline _LIBCPP_INLINE_VISIBILITY
 size_t __libcpp_mbrtowc_l(wchar_t *__pwc, const char *__s, size_t __n,
                    mbstate_t *__ps, locale_t __l)
 {
     __libcpp_locale_guard __current(__l);
     return mbrtowc(__pwc, __s, __n, __ps);
 }
 
-inline _LIBCPP_ALWAYS_INLINE
+inline _LIBCPP_INLINE_VISIBILITY
 int __libcpp_mbtowc_l(wchar_t *__pwc, const char *__pmb, size_t __max, locale_t __l)
 {
     __libcpp_locale_guard __current(__l);
     return mbtowc(__pwc, __pmb, __max);
 }
 
-inline _LIBCPP_ALWAYS_INLINE
+inline _LIBCPP_INLINE_VISIBILITY
 size_t __libcpp_mbrlen_l(const char *__s, size_t __n, mbstate_t *__ps, locale_t __l)
 {
     __libcpp_locale_guard __current(__l);
     return mbrlen(__s, __n, __ps);
 }
 
-inline _LIBCPP_ALWAYS_INLINE
+inline _LIBCPP_INLINE_VISIBILITY
 lconv *__libcpp_localeconv_l(locale_t __l)
 {
     __libcpp_locale_guard __current(__l);
     return localeconv();
 }
 
-inline _LIBCPP_ALWAYS_INLINE
+inline _LIBCPP_INLINE_VISIBILITY
 size_t __libcpp_mbsrtowcs_l(wchar_t *__dest, const char **__src, size_t __len,
                      mbstate_t *__ps, locale_t __l)
 {

libcxx/include/__config

@@ -672,11 +672,9 @@ namespace std {
 
 #if defined(_LIBCPP_COMPILER_MSVC)
 #  define _LIBCPP_INLINE_VISIBILITY __forceinline
-#  define _LIBCPP_ALWAYS_INLINE     __forceinline
 #  define _LIBCPP_EXTERN_TEMPLATE_INLINE_VISIBILITY __forceinline
 #else
 #  define _LIBCPP_INLINE_VISIBILITY __attribute__ ((__always_inline__))
-#  define _LIBCPP_ALWAYS_INLINE     __attribute__ ((__always_inline__))
 #  define _LIBCPP_EXTERN_TEMPLATE_INLINE_VISIBILITY __attribute__ ((__always_inline__))
 #endif
 
@@ -771,14 +769,6 @@ namespace std {
 #  endif
 #endif
 
-#ifndef _LIBCPP_ALWAYS_INLINE
-#  if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
-#    define _LIBCPP_ALWAYS_INLINE  __attribute__ ((__visibility__("hidden"), __always_inline__))
-#  else
-#    define _LIBCPP_ALWAYS_INLINE  __attribute__ ((__always_inline__))
-#  endif
-#endif
-
 #ifndef _LIBCPP_EXTERN_TEMPLATE_INLINE_VISIBILITY
 #  if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
 #    define _LIBCPP_EXTERN_TEMPLATE_INLINE_VISIBILITY __attribute__((__visibility__("default"), __always_inline__))
@@ -889,9 +879,9 @@ template <unsigned> struct __static_assert_check {};
 #  define _LIBCPP_DECLARE_STRONG_ENUM(x) struct _LIBCPP_TYPE_VIS x { enum __lx
 #  define _LIBCPP_DECLARE_STRONG_ENUM_EPILOG(x) \
      __lx __v_; \
-     _LIBCPP_ALWAYS_INLINE x(__lx __v) : __v_(__v) {} \
-     _LIBCPP_ALWAYS_INLINE explicit x(int __v) : __v_(static_cast<__lx>(__v)) {} \
-     _LIBCPP_ALWAYS_INLINE operator int() const {return __v_;} \
+     _LIBCPP_INLINE_VISIBILITY x(__lx __v) : __v_(__v) {} \
+     _LIBCPP_INLINE_VISIBILITY explicit x(int __v) : __v_(static_cast<__lx>(__v)) {} \
+     _LIBCPP_INLINE_VISIBILITY operator int() const {return __v_;} \
      };
 #else  // _LIBCPP_HAS_NO_STRONG_ENUMS
 #  define _LIBCPP_DECLARE_STRONG_ENUM(x) enum class _LIBCPP_ENUM_VIS x