RFR: 8336966: Alpine Linux x86_64 compilation error: sendfile64

[Jan Kratochvil]

Alpine Linux 3.20 x86_64 compilation error:


.../src/java.base/linux/native/libnio/ch/FileDispatcherImpl.c: In function 'Java_sun_nio_ch_FileDispatcherImpl_transferTo0':
.../src/java.base/linux/native/libnio/ch/FileDispatcherImpl.c:117:9: error: implicit declaration of function 'sendfile64'; did you mean 'sendfile'? [-Werror=implicit-function-declaration]
  117 | n = sendfile64(dstFD, srcFD, &offset, (size_t)count);
      | ^~~~~~~~~~
      | sendfile
cc1: all warnings being treated as errors
* For target support_native_java.base_libnio_LinuxNativeDispatcher.o:
In file included from .../src/java.base/share/native/libjava/jni_util.h:30,
                 from .../src/java.base/linux/native/libnio/fs/LinuxNativeDispatcher.c:27:
.../src/java.base/linux/native/libnio/fs/LinuxNativeDispatcher.c: In function 'Java_sun_nio_fs_LinuxNativeDispatcher_directCopy0':
.../src/java.base/linux/native/libnio/fs/LinuxNativeDispatcher.c:214:21: error: implicit declaration of function 'sendfile64'; did you mean 'sendfile'? [-Werror=implicit-function-declaration]
  214 | RESTARTABLE(sendfile64(dst, src, NULL, count), bytes_sent);
      | ^~~~~~~~~~
.../src/java.base/unix/native/libjava/jni_util_md.h:31:15: note: in definition of macro 'RESTARTABLE'
   31 | _result = _cmd; \
      | ^~~~
cc1: all warnings being treated as errors

`make/autoconf/flags-cflags.m4`

  if test "x$OPENJDK_TARGET_OS" = xlinux; then
    CFLAGS_OS_DEF_JVM="-DLINUX -D_FILE_OFFSET_BITS=64"
    CFLAGS_OS_DEF_JDK="-D_GNU_SOURCE -D_REENTRANT -D_FILE_OFFSET_BITS=64"

`sendfile64` were introduced by: #10154 and inherited from https://github.com/openjdk/jdk/commit/a449cd08d7475215fe50218312a5d858068c694c

-------------

Commit messages:
 - 8336966: Alpine Linux x86_64 compilation error: sendfile64

Changes: https://git.openjdk.org/jdk/pull/20295/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=20295&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8336966
  Stats: 2 lines in 2 files changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/20295.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20295/head:pull/20295

PR: https://git.openjdk.org/jdk/pull/20295