build: locally disable new GCC warnings that fail on Flex generated code

* configure.ac: here.

diff --git a/configure.ac b/configure.ac
index df5670cd5d7167b4f6762c270e1577550028671f..734825afbb00af6f8c3c4970c7e35d719e37e98f 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -144,7 +144,9 @@ if test "$enable_gcc_warnings" = yes; then
   done
   # Clang++ 3.2+ reject C code generated by Flex.
   gl_WARN_ADD([-Wno-null-conversion], [FLEX_SCANNER_CXXFLAGS])
-  # So does G++ 4.8 in std=c++11 mode.
+  # So does G++ 4.8...
+  gl_WARN_ADD([-Wno-sign-compare], [FLEX_SCANNER_CXXFLAGS])
+  # ... possiby in std=c++11 mode.
   gl_WARN_ADD([-Wno-zero-as-null-pointer-constant], [FLEX_SCANNER_CXXFLAGS])
   CXXFLAGS=$save_CXXFLAGS
   AC_LANG_POP([C++])