Cygwin: configure: add possibility to skip build of cygserver and utils

This patch adds configure options allowing to disable build of cygserver
and Cygwin utilities. This is useful when one needs to build only
cygwin1.dll and crt0.o with stage1 compiler that is not yet capable of
linking executables as it is missing cygwin1.dll and crt0.o.

Signed-off-by: Radek Bartoň <radek.barton@microsoft.com>

Author: Blackhex

winsup/Makefile.am

@@ -14,10 +14,26 @@ cygdoc_DATA = \
 	CYGWIN_LICENSE \
 	COPYING
 
-SUBDIRS = cygwin cygserver utils testsuite
+SUBDIRS = cygwin testsuite
+
+if BUILD_CYGSERVER
+SUBDIRS += cygserver
+endif
+
+if BUILD_UTILS
+SUBDIRS += utils
+endif
 
 if BUILD_DOC
 SUBDIRS += doc
 endif
 
-cygserver utils testsuite: cygwin
+testsuite: cygwin
+
+if BUILD_CYGSERVER
+cygserver: cygwin
+endif
+
+if BUILD_UTILS
+utils: cygwin
+endif

winsup/configure.ac

@@ -83,6 +83,18 @@ AC_ARG_ENABLE(doc,
 	      enable_doc=yes)
 AM_CONDITIONAL(BUILD_DOC, [test $enable_doc != "no"])
 
+# Disabling build of cygserver and utils is needed for zero-bootstrap build of
+# stage 1 Cygwin toolchain where the linker is not able to produce executables
+# yet.
+AC_ARG_ENABLE(cygserver,
+	      [AS_HELP_STRING([--disable-cygserver], [do not build cygserver])],,
+	      enable_cygserver=yes)
+AM_CONDITIONAL(BUILD_CYGSERVER, [test $enable_cygserver != "no"])
+AC_ARG_ENABLE(utils,
+	      [AS_HELP_STRING([--disable-utils], [do not build utils])],,
+	      enable_utils=yes)
+AM_CONDITIONAL(BUILD_UTILS, [test $enable_utils != "no"])
+
 AC_CHECK_PROGS([DOCBOOK2XTEXI], [docbook2x-texi db2x_docbook2texi])
 if test -z "$DOCBOOK2XTEXI" ; then
     if test "x$enable_doc" != "xno"; then

winsup/cygserver/Makefile.am

@@ -12,7 +12,9 @@ cygserver_flags=$(cxxflags_common) -Wimplicit-fallthrough=5 -Werror -DSYSCONFDIR
 AM_CXXFLAGS = $(CFLAGS)
 
 noinst_LIBRARIES = libcygserver.a
+if BUILD_CYGSERVER
 sbin_PROGRAMS = cygserver
+endif
 bin_SCRIPTS = cygserver-config
 
 cygserver_SOURCES = \

winsup/doc/faq-programming.xml

@@ -698,8 +698,23 @@ Building these programs can be disabled with the <literal>--without-cross-bootst
 option to <literal>configure</literal>.
 </para>
 
+<para>
+Build of <literal>cygserver</literal> can be skipped with
+<literal>--disable-cygserver</literal> and build of other Cygwin utilities with
+<literal>--disable-utils</literal>.
+</para>
+
+<para>
+In combination, <literal>--disable-cygserver</literal>,
+<literal>--disable-dumper</literal>, <literal>--disable-utils</literal>
+and  <literal>--without-cross-bootstrap</literal> allow building of just
+<literal>cygwin1.dll</literal> and <literal>crt0.o</literal> for a stage2
+compiler, when being built with stage1 compiler which does not support linking
+executables yet (because those files are missing).
+</para>
+
 <!-- If you want to run the tests <literal>busybox</literal> and
-     <literal>cygutils-extra<literal> are also required. -->
+     <literal>cygutils-extra</literal> are also required. -->
 
 <para>
 Building the documentation also requires the <literal>dblatex</literal>,