common/autoconf/flags.m4

rev 1453 : 8078245: AARCH64: JDK fails to build due to undefined symbol in libpng
Summary: Add -DPNG_ARM_NEON_OPT=0 to JDK flags to fix build
Reviewed-by: dholmes

*** 483,492 ****
--- 483,499 ----
    elif test "x$TOOLCHAIN_TYPE" = xxlc; then
      CFLAGS_JDK="${CFLAGS_JDK} -qchars=signed -qfullpath -qsaveopt"
      CXXFLAGS_JDK="${CXXFLAGS_JDK} -qchars=signed -qfullpath -qsaveopt"
    fi
  
+   # gcc on aarch64 automatically defines the symbol __ARM_NEON
+   # this causes build failures (undefined symbols in linpng)
+   # work around this by manually turning off ARM Neon optimization
+   if test "x$OPENJDK_TARGET_CPU_ARCH" = "xaarch64"; then
+     CFLAGS_JDKLIB_EXTRA="${CFLAGS_JDKLIB_EXTRA} -DPNG_ARM_NEON_OPT=0"
+   fi
+ 
    if test "x$CFLAGS" != "x${ADDED_CFLAGS}"; then
      AC_MSG_WARN([Ignoring CFLAGS($CFLAGS) found in environment. Use --with-extra-cflags])
    fi
  
    if test "x$CXXFLAGS" != "x${ADDED_CXXFLAGS}"; then