+ # gcc from version 4.8 and above generates "rep; ret" instructions
+ # to avoid performance penalties on certain AMD chips. Older
+ # assemblers detect this as an error, "Error: expecting string
+ # instruction after `rep'"
+ if compareVersions(gcc_version, "4.8") > 0:
+ as_version_raw = readCommand([main['AS'], '-v', '/dev/null'],
+ exception=False).split()
+
+ # version strings may contain extra distro-specific
+ # qualifiers, so play it safe and keep only what comes before
+ # the first hyphen
+ as_version = as_version_raw[-1].split('-')[0] if as_version_raw \
+ else None
+
+ if not as_version or compareVersions(as_version, "2.23") < 0:
+ print termcap.Yellow + termcap.Bold + \
+ 'Warning: This combination of gcc and binutils have' + \
+ ' known incompatibilities.\n' + \
+ ' If you encounter build problems, please update ' + \
+ 'binutils to 2.23.' + \
+ termcap.Normal
+
+ # Make sure we warn if the user has requested to compile with the
+ # Undefined Benahvior Sanitizer and this version of gcc does not
+ # support it.
+ if GetOption('with_ubsan') and \
+ compareVersions(gcc_version, '4.9') < 0:
+ print termcap.Yellow + termcap.Bold + \
+ 'Warning: UBSan is only supported using gcc 4.9 and later.' + \
+ termcap.Normal
+