Gzip support, take 2

.appveyor.yml

@@ -28,7 +28,7 @@ cache:
   - packages-master.tar.gz
 
 install:
-  - '%CYG_ROOT%\setup-%CYG_ARCH%.exe -qnNdO -R %CYG_ROOT% -s http://cygwin.mirror.constant.com -l %CYG_ROOT%/var/cache/setup -P libgmp-devel'
+  - '%CYG_ROOT%\setup-%CYG_ARCH%.exe -qnNdO -R %CYG_ROOT% -s http://cygwin.mirror.constant.com -l %CYG_ROOT%/var/cache/setup -P libgmp-devel,zlib-devel'
 
 # scripts that run after cloning repository
 build_script:

GNUmakefile.in

@@ -57,6 +57,11 @@ GMP_CPPFLAGS = @GMP_CPPFLAGS@
 GMP_LDFLAGS = @GMP_LDFLAGS@
 GMP_LIBS = @GMP_LIBS@
 
+BUILD_ZLIB = @BUILD_ZLIB@
+ZLIB_CPPFLAGS = @ZLIB_CPPFLAGS@
+ZLIB_LDFLAGS = @ZLIB_LDFLAGS@
+ZLIB_LIBS = @ZLIB_LIBS@
+
 READLINE_CPPFLAGS = @READLINE_CPPFLAGS@
 READLINE_LDFLAGS = @READLINE_LDFLAGS@
 READLINE_LIBS = @READLINE_LIBS@

Makefile.rules

@@ -156,11 +156,13 @@ GAP_PKG_CPPFLAGS += $(DEFS)
 
 # Add flags for dependencies
 GAP_CPPFLAGS += $(GMP_CPPFLAGS)
+GAP_CPPFLAGS += $(ZLIB_CPPFLAGS)
 GAP_CPPFLAGS += $(READLINE_CPPFLAGS)
 GAP_CPPFLAGS += $(BOEHM_GC_CPPFLAGS)
 GAP_CPPFLAGS += $(LIBATOMIC_OPS_CPPFLAGS)
 
 GAP_PKG_CPPFLAGS += $(GMP_CPPFLAGS)
+GAP_PKG_CPPFLAGS += $(ZLIB_CPPFLAGS)
 GAP_PKG_CPPFLAGS += $(READLINE_CPPFLAGS)
 GAP_PKG_CPPFLAGS += $(BOEHM_GC_CPPFLAGS)
 GAP_PKG_CPPFLAGS += $(LIBATOMIC_OPS_CPPFLAGS)
@@ -193,6 +195,7 @@ GAP_LDFLAGS = $(ABI_CFLAGS)
 
 # Add flags for dependencies
 GAP_LDFLAGS += $(GMP_LDFLAGS)
+GAP_LDFLAGS += $(ZLIB_LDFLAGS)
 GAP_LDFLAGS += $(READLINE_LDFLAGS)
 GAP_LDFLAGS += $(BOEHM_GC_LDFLAGS)
 GAP_LDFLAGS += $(LIBATOMIC_OPS_LDFLAGS)
@@ -210,6 +213,7 @@ GAP_LIBS =
 
 # Add flags for dependencies
 GAP_LIBS += $(GMP_LIBS)
+GAP_LIBS += $(ZLIB_LIBS)
 GAP_LIBS += $(READLINE_LIBS)
 GAP_LIBS += $(BOEHM_GC_LIBS)
 GAP_LIBS += $(LIBATOMIC_OPS_LIBS)
@@ -540,6 +544,36 @@ gmp:
 endif # BUILD_GMP
 
 
+#
+# ZLIB
+#
+ifeq ($(BUILD_ZLIB),yes)
+
+ZLIB_BUILDDIR := extern/build/zlib
+ZLIB_PREFIX := extern/install/zlib
+# ZLIB_PREREQ := $(ZLIB_BUILDDIR)/config.status
+ZLIB_FILES := $(ZLIB_PREFIX)/include/zlib.h
+
+EXTERN_FILES += $(ZLIB_FILES)
+
+zlib: $(ZLIB_FILES)
+$(ZLIB_FILES):
+	MAKE=$(MAKE) CFLAGS="$(CFLAGS) $(ABI_CFLAGS)" $(srcdir)/cnf/build-extern.sh zlib "$(abs_srcdir)/extern/zlib"
+
+.PHONY: zlib
+
+# TODO: add clean, distclean, check targets?
+# TODO: pass on cachfile?
+# TODO: pass on certain *FLAGS ?
+
+else
+
+zlib:
+	echo "Using external zlib, nothing to do be done"
+
+endif # BUILD_ZLIB
+
+
 #
 # libatomic_ops
 #

configure.ac

@@ -349,6 +349,66 @@ dnl remove this eventually.
 AC_DEFINE([USE_GMP], [1], [for backwards compatibility])
 
 
+dnl Find zlib
+AC_ARG_WITH([zlib],
+  [AS_HELP_STRING([--with-zlib@<:@=builtin|PREFIX@:>@],
+    [prefix of zlib installation. e.g. /usr/local; specify `builtin' to let GAP builds its own version of zlib])],
+    [],[with_zlib=yes])
+
+BUILD_ZLIB=no
+ZLIB_CPPFLAGS=
+ZLIB_LDFLAGS=
+ZLIB_LIBS="-lz"
+AS_CASE([$with_zlib],
+  [builtin],[
+    # user explicitly requested to use builtin zlib
+    BUILD_ZLIB=yes
+    AC_MSG_NOTICE([Using bundled zlib])
+  ],
+  [no],[
+    AC_MSG_ERROR([Building without zlib is not supported])
+  ],
+  [system],[with_zlib=yes],  dnl supported for backwards compatibility with old build system
+  [yes],[],
+  [*],[
+    ZLIB_CPPFLAGS="-I${with_zlib}/include"
+    ZLIB_LDFLAGS="-L${with_zlib}/lib"
+  ]
+)
+
+AS_IF([test $BUILD_ZLIB = no],
+  [
+    # try to link against zlib
+    AX_CHECK_LIBRARY([ZLIB], [zlib.h], [z], [inflateEnd])
+    AS_IF([test $ax_cv_have_ZLIB = no],[
+        AS_IF([test "x$with_zlib" = "xyes"],[
+          BUILD_ZLIB=yes
+          AC_MSG_NOTICE([No usable zlib found, switching to included zlib])
+        ],
+        [AC_MSG_ERROR([zlib not found at prefix $with_zlib])]
+        )
+    ])
+  ])
+
+# Use bundled zlib if requested
+AS_IF([test x$BUILD_ZLIB = xyes],[
+  AS_CASE([$host_os],
+    [*cygwin*],[
+        AC_MSG_ERROR([Builtin zlib not supported on cygwin. Install zlib-devel package])
+    ]
+  )
+  BUILD_ZLIB=yes
+  ZLIB_CPPFLAGS='-I${abs_builddir}/extern/install/zlib/include'
+  ZLIB_LDFLAGS='${abs_builddir}/extern/install/zlib/lib/libz.a'
+  ZLIB_LIBS=
+])
+
+AC_SUBST([BUILD_ZLIB])
+AC_SUBST([ZLIB_CPPFLAGS])
+AC_SUBST([ZLIB_LDFLAGS])
+AC_SUBST([ZLIB_LIBS])
+
+
 dnl Find GNU readline
 AC_ARG_WITH([readline],
   [AS_HELP_STRING([--with-readline@<:@=PREFIX@:>@],