examples: beware of the portability of flex --header-file

The option --header was introduced in version 2.5.6.
The option --header-file was introduced in version 2.6.4.
Reported by Bruno Haible.
https://lists.gnu.org/r/bug-bison/2020-05/msg00013.html

So use --header, and do bother with versions that don't support it.

* m4/flex.m4: Check whether flex supports --header.
* configure.ac (FLEX_WORKS, FLEX_CXX_WORKS): Set to false if it doesn't.
* * examples/c/reccalc/local.mk, examples/c/reccalc/Makefile:
Use --header rather than --header-file.
This commit is contained in:
Akim Demaille
2020-05-03 09:51:18 +02:00
parent ccaa8e29f9
commit 392f3caef6
4 changed files with 22 additions and 5 deletions

View File

@@ -12,7 +12,7 @@ all: $(BASE)
$(BISON) $(BISONFLAGS) --defines --xml --graph=$*.gv -o $*.c $<
%.c %.h: %.l
$(FLEX) $(FLEXFLAGS) -o$*.c --header-file=$*.h $<
$(FLEX) $(FLEXFLAGS) -o$*.c --header=$*.h $<
scan.o: parse.h
parse.o: scan.h

View File

@@ -69,7 +69,9 @@ DASH = -
$(AM_V_LEX)rm -f $@ $@.tmp
$(AM_V_at)$(MKDIR_P) %D%
$(AM_V_at)touch $@.tmp
$(AM_V_at)$(LEX) $(AM_LFLAGS) $(LFLAGS) -o%D%/scan.c --header-file=%D%/scan.h $(srcdir)/%D%/scan.l
## --header introduced in 2.5.6, renamed as --header-file in 2.6.4.
## Backward compatibility ensured since --header is an unambiguous prefix.
$(AM_V_at)$(LEX) $(AM_LFLAGS) $(LFLAGS) -o%D%/scan.c --header=%D%/scan.h $(srcdir)/%D%/scan.l
$(AM_V_at)mv $@.tmp $@