8252407: Build failure with gcc-8+ and asan

Reviewed-by: ihse, kbarrett

Author: Eric Liu

make/autoconf/flags-cflags.m4

@@ -231,8 +231,14 @@ AC_DEFUN([FLAGS_SETUP_OPTIMIZATION],
     # -D_FORTIFY_SOURCE=2 hardening option needs optimization (at least -O1) enabled
     # set for lower O-levels -U_FORTIFY_SOURCE to overwrite previous settings
     if test "x$OPENJDK_TARGET_OS" = xlinux -a "x$DEBUG_LEVEL" = "xfastdebug"; then
-      ENABLE_FORTIFY_CFLAGS="-D_FORTIFY_SOURCE=2"
       DISABLE_FORTIFY_CFLAGS="-U_FORTIFY_SOURCE"
+      # ASan doesn't work well with _FORTIFY_SOURCE
+      # See https://github.com/google/sanitizers/wiki/AddressSanitizer#faq
+      if test "x$ASAN_ENABLED" = xyes; then
+        ENABLE_FORTIFY_CFLAGS="${DISABLE_FORTIFY_CFLAGS}"
+      else
+        ENABLE_FORTIFY_CFLAGS="-D_FORTIFY_SOURCE=2"
+      fi
       C_O_FLAG_HIGHEST_JVM="${C_O_FLAG_HIGHEST_JVM} ${ENABLE_FORTIFY_CFLAGS}"
       C_O_FLAG_HIGHEST="${C_O_FLAG_HIGHEST} ${ENABLE_FORTIFY_CFLAGS}"
       C_O_FLAG_HI="${C_O_FLAG_HI} ${ENABLE_FORTIFY_CFLAGS}"

make/autoconf/jdk-options.m4

@@ -423,7 +423,10 @@ AC_DEFUN_ONCE([JDKOPT_SETUP_ADDRESS_SANITIZER],
         fi
       ],
       IF_ENABLED: [
-        ASAN_CFLAGS="-fsanitize=address -fno-omit-frame-pointer"
+        # ASan is simply incompatible with gcc -Wstringop-truncation. See
+        # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85650
+        # It's harmless to be suppressed in clang as well.
+        ASAN_CFLAGS="-fsanitize=address -Wno-stringop-truncation -fno-omit-frame-pointer"
         ASAN_LDFLAGS="-fsanitize=address"
         JVM_CFLAGS="$JVM_CFLAGS $ASAN_CFLAGS"
         JVM_LDFLAGS="$JVM_LDFLAGS $ASAN_LDFLAGS"