diff options
| author | Jakub Jelinek <jakub@redhat.com> | 2022-11-08 00:35:09 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2022-11-08 00:35:09 +0100 |
| commit | b457b779427b0f7b3fbac447811c9c52db5bc79e (patch) | |
| tree | 368fc5b5330363ee3f170a021f34fd349027ccce | |
| parent | 93ab7d03dfbdd096c1d3c83e92d794bf4eed18df (diff) | |
libstdc++: Fix up libstdc++ build against glibc 2.25 or older [PR107562]
On Mon, Nov 07, 2022 at 05:48:42PM +0000, Jonathan Wakely wrote:
> On Mon, 7 Nov 2022 at 16:11, Joseph Myers <joseph@codesourcery.com> wrote:
> >
> > On Wed, 2 Nov 2022, Jakub Jelinek via Gcc-patches wrote:
> >
> > > APIs. So that one can build gcc against older glibc and then compile
> > > user programs on newer glibc, the patch uses weak references unless
> > > gcc is compiled against glibc 2.26+. strfromf128 unfortunately can't
> >
> > This support for older glibc doesn't actually seem to be working, on an
> > older system with glibc 2.19 I'm seeing
> >
> > /scratch/jmyers/fsf/gcc-mainline/libstdc++-v3/src/c++17/floating_to_chars.cc:52:3: error: expected initializer before '__asm'
> > 52 | __asm ("strfromf128");
> > | ^~~~~
> >
> > and a series of subsequent errors.
>
> This seems to "fix" it (not sure if it's right though):
>
> #ifndef _GLIBCXX_HAVE_FLOAT128_MATH
> extern "C" _Float128 __strtof128(const char*, char**)
> __attribute__((__weak__));
> #endif
> extern "C" _Float128 __strtof128(const char*, char**)
> __asm ("strtof128");
It is, but floating_from_chars.cc has the same problem,
and I think we can avoid the duplication, like this:
2022-11-08 Jakub Jelinek <jakub@redhat.com>
PR libstdc++/107562
* src/c++17/floating_from_chars.cc (__strtof128): Put __asm before
__attribute__.
* src/c++17/floating_to_chars.cc (__strfromf128): Likewise.
| -rw-r--r-- | libstdc++-v3/src/c++17/floating_from_chars.cc | 3 | ||||
| -rw-r--r-- | libstdc++-v3/src/c++17/floating_to_chars.cc | 3 |
2 files changed, 4 insertions, 2 deletions
diff --git a/libstdc++-v3/src/c++17/floating_from_chars.cc b/libstdc++-v3/src/c++17/floating_from_chars.cc index 11a9be68770..29eb4634e9d 100644 --- a/libstdc++-v3/src/c++17/floating_from_chars.cc +++ b/libstdc++-v3/src/c++17/floating_from_chars.cc @@ -63,10 +63,11 @@ extern "C" __ieee128 __strtoieee128(const char*, char**); && defined(__GLIBC_PREREQ) #define USE_STRTOF128_FOR_FROM_CHARS 1 extern "C" _Float128 __strtof128(const char*, char**) + __asm ("strtof128") #ifndef _GLIBCXX_HAVE_FLOAT128_MATH __attribute__((__weak__)) #endif - __asm ("strtof128"); + ; #endif #if _GLIBCXX_FLOAT_IS_IEEE_BINARY32 && _GLIBCXX_DOUBLE_IS_IEEE_BINARY64 \ diff --git a/libstdc++-v3/src/c++17/floating_to_chars.cc b/libstdc++-v3/src/c++17/floating_to_chars.cc index d6be6465b12..afce8d74c12 100644 --- a/libstdc++-v3/src/c++17/floating_to_chars.cc +++ b/libstdc++-v3/src/c++17/floating_to_chars.cc @@ -46,10 +46,11 @@ extern "C" int __sprintfieee128(char*, const char*, ...); #elif __FLT128_MANT_DIG__ == 113 && __LDBL_MANT_DIG__ != 113 \ && defined(__GLIBC_PREREQ) extern "C" int __strfromf128(char*, size_t, const char*, _Float128) + __asm ("strfromf128") #ifndef _GLIBCXX_HAVE_FLOAT128_MATH __attribute__((__weak__)) #endif - __asm ("strfromf128"); + ; #endif // This implementation crucially assumes float/double have the |