Improve zlib detection logic (#7430)
Current logic expects zlib is in /usr or /usr/local or a path manually
specified, and it doesn't pass -lz to a linker if zlib is not in any of them.
macOS doesn't have zlib (or libz) in /usr or /usr/local but in another place,
and you don't have to explicitly specify the path because it's the standard path.
In other words, just passing -lz to clang/gcc works without -I nor -L.
New logic passes -lz if zlib is available without additional path information.
diff --git a/build/zlib.m4 b/build/zlib.m4
index b268914..4f145f2 100644
--- a/build/zlib.m4
+++ b/build/zlib.m4
@@ -22,13 +22,12 @@
dnl TS_CHECK_ZLIB: look for zlib libraries and headers
dnl
AC_DEFUN([TS_CHECK_ZLIB], [
-enable_zlib=no
+enable_zlib=yes
AC_ARG_WITH(zlib, [AC_HELP_STRING([--with-zlib=DIR],[use a specific zlib library])],
[
if test "x$withval" != "xyes" && test "x$withval" != "x"; then
zlib_base_dir="$withval"
if test "$withval" != "no"; then
- enable_zlib=yes
case "$withval" in
*":"*)
zlib_include="`echo $withval |sed -e 's/:.*$//'`"
@@ -46,7 +45,6 @@
])
if test "x$zlib_base_dir" = "x"; then
- AC_MSG_CHECKING([for zlib location])
AC_CACHE_VAL(ats_cv_zlib_dir,[
for dir in /usr/local /usr ; do
if test -d $dir && test -f $dir/include/zlib.h; then
@@ -56,19 +54,15 @@
done
])
zlib_base_dir=$ats_cv_zlib_dir
- if test "x$zlib_base_dir" = "x"; then
- enable_zlib=no
- AC_MSG_RESULT([not found])
- else
- enable_zlib=yes
+ if test "x$zlib_base_dir" != "x"; then
zlib_include="$zlib_base_dir/include"
zlib_ldflags="$zlib_base_dir/lib"
- AC_MSG_RESULT([$zlib_base_dir])
fi
else
if test -d $zlib_include && test -d $zlib_ldflags && test -f $zlib_include/zlib.h; then
AC_MSG_RESULT([ok])
else
+ enable_zlib=no
AC_MSG_RESULT([not found])
fi
fi
@@ -78,7 +72,7 @@
saved_cppflags=$CPPFLAGS
zlib_have_headers=0
zlib_have_libs=0
- if test "$zlib_base_dir" != "/usr"; then
+ if test "$zlib_base_dir" != "/usr" && test "x$zlib_base_dir" != "x"; then
TS_ADDTO(CPPFLAGS, [-I${zlib_include}])
TS_ADDTO(LDFLAGS, [-L${zlib_ldflags}])
TS_ADDTO_RPATH(${zlib_ldflags})
