build system: replace hard-coded flex include dir with that found by autoconf, #575

configure.ac

 dnl Process this file with autoconf to produce a configure script.
 
-dnl Copyright (C) 2009-2013 Dynare Team
+dnl Copyright (C) 2009-2014 Dynare Team
 dnl
 dnl This file is part of Dynare.
 dnl
@@ -62,6 +62,9 @@ AX_PROG_LN_S
 AC_PROG_MKDIR_P
 
 AM_PROG_LEX
+# Hack to get lex include dir, ticket #575
+AC_PATH_PROG([LEXPATH], [$LEX])
+AC_SUBST([LEXINC], [`eval "echo $LEXPATH | sed 's|$LEX$|../include|'"`])
 
 AC_CHECK_PROG([YACC], [bison], [bison])
 if test "x$YACC" = "x"; then

preprocessor/Makefile.am

@@ -61,7 +61,7 @@ dynare_m_LDADD = macro/libmacro.a
 
 DynareFlex.cc FlexLexer.h: DynareFlex.ll
 	$(LEX) -oDynareFlex.cc DynareFlex.ll
-	cp /usr/include/FlexLexer.h .
+	cp $(LEXINC)/FlexLexer.h .
 
 DynareBison.cc DynareBison.hh location.hh stack.hh position.hh: DynareBison.yy
 	$(YACC) -o DynareBison.cc DynareBison.yy