kconfig: fix compatibility with very old versions of flex

See https://github.com/crosstool-ng/crosstool-ng/commit/4e762e4918d8755e762db1db328760dfa5fc7a14

Closes https://github.com/espressif/esp-idf/issues/2703

diff --git a/tools/kconfig/Makefile b/tools/kconfig/Makefile
index cd00640430c2603bfb556e27b082de284123e9da..106ffb6b40e55eba790847eb3acb2707c5117b3a 100644 (file)
--- a/tools/kconfig/Makefile
+++ b/tools/kconfig/Makefile
@@ -334,7 +334,7 @@ conf-idf: $(conf-objs)
 zconf.tab.c: zconf.lex.c
 
 zconf.lex.c: $(SRCDIR)/zconf.l
-       flex -L -P zconf -o zconf.lex.c $<
+       flex -L -Pzconf -ozconf.lex.c $<
 
 zconf.hash.c: $(SRCDIR)/zconf.gperf
 # strip CRs on Windows systems where gperf will otherwise barf on them