From da21733178b34eea303964db5a05e8a3ee4095b4 Mon Sep 17 00:00:00 2001
From: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Date: Sat, 26 Aug 2017 15:17:06 +0200
Subject: [PATCH] build: make it possible to disable the build of the flex
 program

The flex program uses fork(), which isn't available on noMMU
systems. However, the libfl library does not use fork(), and be used
by other programs/libraries.

Therefore, it makes sense to provide an option to disable the build of
the flex program.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

---
Submitted-upstream: https://github.com/westes/flex/pull/256
Refused. We'll have to adapt when they do a new release...
---
 Makefile.am     | 2 ++
 configure.ac    | 6 ++++++
 doc/Makefile.am | 4 ++++
 src/Makefile.am | 3 +++
 4 files changed, 15 insertions(+)

diff --git a/Makefile.am b/Makefile.am
index e790e9d..8b57bc9 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -62,8 +62,10 @@ ChangeLog: $(srcdir)/tools/git2cl
 indent:
 	cd src && $(MAKE) $(AM_MAKEFLAGS) indent
 
+if ENABLE_PROGRAM
 install-exec-hook:
 	cd $(DESTDIR)$(bindir) && \
 		$(LN_S) -f flex$(EXEEXT) flex++$(EXEEXT)
+endif
 
 .PHONY: ChangeLog indent
diff --git a/configure.ac b/configure.ac
index 8882016..f49872b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -75,6 +75,12 @@ AC_ARG_ENABLE([libfl],
   [], [enable_libfl=yes])
 AM_CONDITIONAL([ENABLE_LIBFL], [test "x$enable_libfl" = xyes])
 
+AC_ARG_ENABLE([program],
+  [AS_HELP_STRING([--disable-program],
+                  [do not build the flex program, only the libfl library])],
+  [], [enable_program=yes])
+AM_CONDITIONAL([ENABLE_PROGRAM], [test "x$enable_program" = xyes])
+
 # --disable-bootstrap is intended only to workaround problems with bootstrap
 # (e.g. when cross-compiling flex or when bootstrapping has bugs).
 # Ideally we should be able to bootstrap even when cross-compiling.
diff --git a/src/Makefile.am b/src/Makefile.am
index 0d13a5a..c73bc17 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -4,7 +4,10 @@ LIBS = @LIBS@
 
 m4 = @M4@
 
+if ENABLE_PROGRAM
 bin_PROGRAMS = flex
+endif
+
 if ENABLE_BOOTSTRAP
 noinst_PROGRAMS = stage1flex
 endif
-- 
2.9.4