Hi,
The rule for generating a file with a C++ source extension from a lex
".ll" file isn't correct for the case when someone enables C++ scanner
support in GNU Flex. For example, specifying a file "lexer.ll" in the
"foo_SOURCES" variable of a given program "foo" causes the following
rule to be generated:
.ll.cc:
$(LEXCOMPILE) $<
sed '/^#/ s|$(LEX_OUTPUT_ROOT)\.c|$@|' $(LEX_OUTPUT_ROOT).c >$@
rm -f $(LEX_OUTPUT_ROOT).c
This rule assumes that $(LEX) will always generate a file with a `.c'
extension. This assumption doesn't hold for GNU flex C++ scanners that
are enabled by specifying the "%option c++" option in the GNU flex input
file or by using the "-+" command line option. In those cases, the
generated scanner will have a ".cc" extension. For example:
$ make lexer.cc
flex lexer.ll
sed '/^#/ s|lex.yy\.c|lexer.cc|' lex.yy.c >lexer.cc
sed: can't read lex.yy.c: No such file or directory
make: *** [lexer.cc] Error 2
`lex.yy.c' doesn't exist, but 'lex.yy.cc' does exist.
Would it be possible for Automake to tweak the lex rule if "%option c++"
is found in the lex source/input file, or if the "-+" flag is found in
the $(AM_LFLAGS) make variable?
Thanks,
-Ossama
--
Ossama Othman <ossama @ dre . vanderbilt . edu>
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