Hi, Frederik Fouvry <[EMAIL PROTECTED]> writes:
> I'm using > > AC_CHECK_HEADERS([ecl.h]) > > in configure.ac, and that gives the following in the log file > (autoconf 2.57): > > configure:5067: checking ecl.h usability > configure:5080: gcc -c -g -O2 -I/proj/contrib/lkb/latest/include > -I/proj/contrib/lib/ecl/h conftest.c >&5 > configure:5083: $? = 0 > configure:5086: test -s conftest.o > configure:5089: $? = 0 > configure:5099: result: yes > configure:5103: checking ecl.h presence > configure:5114: gcc -E -I/proj/contrib/lkb/latest/include -I/proj/contrib/lib/ecl/h > conftest.c > configure:5120: $? = 0 > configure:5139: result: yes > configure:5175: checking for ecl.h > configure:5182: result: yes > > It first tests whether it can compile with the header file, and > then tests if the file exists or not. Is the second test not > subsumed by the first one (if that one is successful)? The first test uses $CFLAGS and $CPPFLAGS, while the second only uses $CPPFLAGS. If you have some -I and -D in your $CFLAGS, the results will differ. (I'm not justifying the double check. I'm just saying that the second is not entirely redundant :-) - Hari -- Raja R Harinath ------------------------------ [EMAIL PROTECTED]
