Auto: mirroring installation structure in build tree.

This makes the build tree more organized, which is good for adding new
stuff.  Now, it's useful for example for adding manual pages in man3/,
but it may be useful in the future for example for extending the build
system to run linters (e.g., clang-tidy(1), Clang analyzer, ...) on the
C source code.

Previously, the build tree was quite flat, and looked like this (after
`./configure && make`):

    $ tree -I src build
    build
    ├── Makefile
    ├── autoconf.data
    ├── autoconf.err
    ├── echo
    ├── libnxt.a
    ├── nxt_auto_config.h
    ├── nxt_version.h
    ├── unitd
    └── unitd.8

    1 directory, 9 files

And after this patch, it looks like this:

    $ tree -I src build
    build
    ├── Makefile
    ├── autoconf.data
    ├── autoconf.err
    ├── bin
    │   └── echo
    ├── include
    │   ├── nxt_auto_config.h
    │   └── nxt_version.h
    ├── lib
    │   ├── libnxt.a
    │   └── unit
    │       └── modules
    ├── sbin
    │   └── unitd
    ├── share
    │   └── man
    │       └── man8
    │           └── unitd.8
    └── var
        ├── lib
        │   └── unit
        ├── log
        │   └── unit
        └── run
            └── unit

    17 directories, 9 files

It also solves one issue introduced in
5a37171f733f ("Added default values for pathnames.").  Before that
commit, it was possible to run unitd from the build system
(`./build/unitd`).  Now, since it expects files in a very specific
location, that has been broken.  By having a directory structure that
mirrors the installation, it's possible to trick it to believe it's
installed, and run it from there:

    $ ./configure --prefix=./build
    $ make
    $ ./build/sbin/unitd

Fixes: 5a37171f733f ("Added default values for pathnames.")
Reported-by: Liam Crilly <liam@nginx.com>
Reviewed-by: Konstantin Pavlov <thresh@nginx.com>
Reviewed-by: Andrew Clayton <a.clayton@nginx.com>
Cc: Andrei Zeliankou <zelenkov@nginx.com>
Cc: Zhidao Hong <z.hong@f5.com>
Signed-off-by: Alejandro Colomar <alx@nginx.com>

1 files changed, 37 insertions, 41 deletions

diff --git a/auto/make b/auto/make
index a8f17e73..0890b0c3 100644
--- a/auto/make
+++ b/auto/make
@@ -7,9 +7,6 @@
 
 $echo "creating $NXT_MAKEFILE"
 
-mkdir -p $NXT_BUILD_DIR/src \
-         $NXT_BUILD_DIR/src/test
-
 
 cat << END > $NXT_MAKEFILE
 
@@ -25,8 +22,8 @@ NXT_MODULE_LINK =	$NXT_MODULE_LINK
 all: $NXT_DAEMON manpage
 
 .PHONY: $NXT_DAEMON manpage
-$NXT_DAEMON: $NXT_BUILD_DIR/$NXT_DAEMON
-manpage: $NXT_BUILD_DIR/unitd.8
+$NXT_DAEMON: $NXT_BUILD_DIR/sbin/$NXT_DAEMON
+manpage: $NXT_BUILD_DIR/share/man/man8/unitd.8
 
 END
 
@@ -35,7 +32,7 @@ END
 
 $echo -n "NXT_LIB_INCS =" >> $NXT_MAKEFILE
 
-for nxt_inc in src $NXT_BUILD_DIR
+for nxt_inc in src $NXT_BUILD_DIR/include
 do
     $echo -n " -I $nxt_inc" >> $NXT_MAKEFILE
 done
@@ -88,20 +85,17 @@ END
 
 cat << END >> $NXT_MAKEFILE
 
-libnxt:	$NXT_BUILD_DIR/$NXT_LIB_SHARED $NXT_BUILD_DIR/$NXT_LIB_STATIC
+libnxt:	$NXT_BUILD_DIR/lib/$NXT_LIB_SHARED $NXT_BUILD_DIR/lib/$NXT_LIB_STATIC
 
-$NXT_BUILD_DIR/$NXT_LIB_SHARED:	\$(NXT_LIB_OBJS)
-	\$(NXT_SHARED_LOCAL_LINK) -o $NXT_BUILD_DIR/$NXT_LIB_SHARED \\
-		\$(NXT_LIB_OBJS) \\
+$NXT_BUILD_DIR/lib/$NXT_LIB_SHARED: \$(NXT_LIB_OBJS)
+	\$(NXT_SHARED_LOCAL_LINK) -o \$@ \$(NXT_LIB_OBJS) \\
 		$NXT_LIBM $NXT_LIBS $NXT_LIB_AUX_LIBS
 
-$NXT_BUILD_DIR/$NXT_LIB_STATIC:	\$(NXT_LIB_OBJS)
-	$NXT_STATIC_LINK $NXT_BUILD_DIR/$NXT_LIB_STATIC \\
-		\$(NXT_LIB_OBJS)
+$NXT_BUILD_DIR/lib/$NXT_LIB_STATIC: \$(NXT_LIB_OBJS)
+	$NXT_STATIC_LINK \$@ \$(NXT_LIB_OBJS)
 
-$NXT_BUILD_DIR/$NXT_LIB_UNIT_STATIC:	\$(NXT_LIB_UNIT_OBJS)
-	$NXT_STATIC_LINK $NXT_BUILD_DIR/$NXT_LIB_UNIT_STATIC \\
-		\$(NXT_LIB_UNIT_OBJS)
+$NXT_BUILD_DIR/lib/$NXT_LIB_UNIT_STATIC: \$(NXT_LIB_UNIT_OBJS)
+	$NXT_STATIC_LINK \$@ \$(NXT_LIB_UNIT_OBJS)
 
 END
 
@@ -195,55 +189,55 @@ tests:		$NXT_BUILD_DIR/tests $NXT_BUILD_DIR/utf8_file_name_test \\
 			$NXT_BUILD_DIR/unit_websocket_echo
 
 $NXT_BUILD_DIR/tests: \$(NXT_TEST_OBJS) \\
-			$NXT_BUILD_DIR/$NXT_LIB_STATIC
+			$NXT_BUILD_DIR/lib/$NXT_LIB_STATIC
 	\$(NXT_EXEC_LINK) -o $NXT_BUILD_DIR/tests \\
 		\$(CFLAGS) \$(NXT_TEST_OBJS) \\
-		$NXT_BUILD_DIR/$NXT_LIB_STATIC \\
+		$NXT_BUILD_DIR/lib/$NXT_LIB_STATIC \\
 		$NXT_LD_OPT $NXT_LIBM $NXT_LIBS $NXT_LIB_AUX_LIBS
 
 $NXT_BUILD_DIR/utf8_file_name_test: $NXT_LIB_UTF8_FILE_NAME_TEST_SRCS \\
-			$NXT_BUILD_DIR/$NXT_LIB_STATIC
+			$NXT_BUILD_DIR/lib/$NXT_LIB_STATIC
 	\$(CC) \$(CFLAGS) \$(NXT_LIB_INCS) $NXT_LIB_AUX_CFLAGS \\
 		-o $NXT_BUILD_DIR/utf8_file_name_test \\
 		$NXT_LIB_UTF8_FILE_NAME_TEST_SRCS \\
-		$NXT_BUILD_DIR/$NXT_LIB_STATIC \\
+		$NXT_BUILD_DIR/lib/$NXT_LIB_STATIC \\
 		$NXT_LD_OPT $NXT_LIBM $NXT_LIBS $NXT_LIB_AUX_LIBS
 
 $NXT_BUILD_DIR/ncq_test: $NXT_BUILD_DIR/src/test/nxt_ncq_test.o \\
-			$NXT_BUILD_DIR/$NXT_LIB_STATIC
+			$NXT_BUILD_DIR/lib/$NXT_LIB_STATIC
 	\$(NXT_EXEC_LINK) -o $NXT_BUILD_DIR/ncq_test \\
 		\$(CFLAGS) $NXT_BUILD_DIR/src/test/nxt_ncq_test.o \\
-		$NXT_BUILD_DIR/$NXT_LIB_STATIC \\
+		$NXT_BUILD_DIR/lib/$NXT_LIB_STATIC \\
 		$NXT_LD_OPT $NXT_LIBM $NXT_LIBS $NXT_LIB_AUX_LIBS
 
 $NXT_BUILD_DIR/vbcq_test: $NXT_BUILD_DIR/src/test/nxt_vbcq_test.o \\
-			$NXT_BUILD_DIR/$NXT_LIB_STATIC
+			$NXT_BUILD_DIR/lib/$NXT_LIB_STATIC
 	\$(NXT_EXEC_LINK) -o $NXT_BUILD_DIR/vbcq_test \\
 		\$(CFLAGS) $NXT_BUILD_DIR/src/test/nxt_vbcq_test.o \\
-		$NXT_BUILD_DIR/$NXT_LIB_STATIC \\
+		$NXT_BUILD_DIR/lib/$NXT_LIB_STATIC \\
 		$NXT_LD_OPT $NXT_LIBM $NXT_LIBS $NXT_LIB_AUX_LIBS
 
 $NXT_BUILD_DIR/unit_app_test: $NXT_BUILD_DIR/src/test/nxt_unit_app_test.o \\
-		$NXT_BUILD_DIR/$NXT_LIB_UNIT_STATIC
+		$NXT_BUILD_DIR/lib/$NXT_LIB_UNIT_STATIC
 	\$(NXT_EXEC_LINK) -o $NXT_BUILD_DIR/unit_app_test \\
 		\$(CFLAGS) $NXT_BUILD_DIR/src/test/nxt_unit_app_test.o \\
-		$NXT_BUILD_DIR/$NXT_LIB_UNIT_STATIC \\
+		$NXT_BUILD_DIR/lib/$NXT_LIB_UNIT_STATIC \\
 		$NXT_LD_OPT $NXT_LIBM $NXT_LIBS $NXT_LIB_AUX_LIBS
 
 $NXT_BUILD_DIR/unit_websocket_chat: \\
 		$NXT_BUILD_DIR/src/test/nxt_unit_websocket_chat.o \\
-		$NXT_BUILD_DIR/$NXT_LIB_UNIT_STATIC
+		$NXT_BUILD_DIR/lib/$NXT_LIB_UNIT_STATIC
 	\$(NXT_EXEC_LINK) -o $NXT_BUILD_DIR/unit_websocket_chat \\
 		\$(CFLAGS) $NXT_BUILD_DIR/src/test/nxt_unit_websocket_chat.o \\
-		$NXT_BUILD_DIR/$NXT_LIB_UNIT_STATIC \\
+		$NXT_BUILD_DIR/lib/$NXT_LIB_UNIT_STATIC \\
 		$NXT_LD_OPT $NXT_LIBM $NXT_LIBS $NXT_LIB_AUX_LIBS
 
 $NXT_BUILD_DIR/unit_websocket_echo: \\
 		$NXT_BUILD_DIR/src/test/nxt_unit_websocket_echo.o \\
-		$NXT_BUILD_DIR/$NXT_LIB_UNIT_STATIC
+		$NXT_BUILD_DIR/lib/$NXT_LIB_UNIT_STATIC
 	\$(NXT_EXEC_LINK) -o $NXT_BUILD_DIR/unit_websocket_echo \\
 		\$(CFLAGS) $NXT_BUILD_DIR/src/test/nxt_unit_websocket_echo.o \\
-		$NXT_BUILD_DIR/$NXT_LIB_UNIT_STATIC \\
+		$NXT_BUILD_DIR/lib/$NXT_LIB_UNIT_STATIC \\
 		$NXT_LD_OPT $NXT_LIBM $NXT_LIBS $NXT_LIB_AUX_LIBS
 
 END
@@ -264,7 +258,7 @@ END
 fi
 
 
-NXT_MAKE_INCS="src $NXT_BUILD_DIR"
+NXT_MAKE_INCS="src $NXT_BUILD_DIR/include"
 NXT_MAKE_SRCS="$NXT_SRCS"
 
 
@@ -298,10 +292,10 @@ $echo >> $NXT_MAKEFILE
 
 cat << END >> $NXT_MAKEFILE
 
-$NXT_BUILD_DIR/$NXT_DAEMON:	$NXT_BUILD_DIR/$NXT_LIB_STATIC \\
+$NXT_BUILD_DIR/sbin/$NXT_DAEMON:	$NXT_BUILD_DIR/lib/$NXT_LIB_STATIC \\
 				\$(NXT_OBJS)
-	\$(NXT_EXEC_LINK) -o $NXT_BUILD_DIR/$NXT_DAEMON \$(CFLAGS) \\
-		\$(NXT_OBJS) $NXT_BUILD_DIR/$NXT_LIB_STATIC \\
+	\$(NXT_EXEC_LINK) -o \$@ \$(CFLAGS) \\
+		\$(NXT_OBJS) $NXT_BUILD_DIR/lib/$NXT_LIB_STATIC \\
 		$NXT_LIBM $NXT_LIBS $NXT_LIB_AUX_LIBS
 
 END
@@ -311,7 +305,8 @@ END
 
 cat << END >> $NXT_MAKEFILE
 
-$NXT_BUILD_DIR/unitd.8: docs/man/unitd.8.in $NXT_BUILD_DIR/nxt_auto_config.h
+$NXT_BUILD_DIR/share/man/man8/unitd.8: docs/man/unitd.8.in \\
+				$NXT_BUILD_DIR/include/nxt_auto_config.h
 	sed -e "s|%%ERROR_LOG_PATH%%|$NXT_LOG|" \\
 		-e "s|%%PID_PATH%%|$NXT_PID|" \\
 		-e "s|%%SOCKET_PATH%%|$NXT_CONTROL|" \\
@@ -365,7 +360,7 @@ install-check:
 ${NXT_DAEMON}-install: $NXT_DAEMON install-check
 	test -d \$(DESTDIR)$NXT_SBINDIR \
 		|| install -d \$(DESTDIR)$NXT_SBINDIR
-	install -p $NXT_BUILD_DIR/$NXT_DAEMON \$(DESTDIR)$NXT_SBINDIR/
+	install -p $NXT_BUILD_DIR/sbin/$NXT_DAEMON \$(DESTDIR)$NXT_SBINDIR/
 	test -d \$(DESTDIR)$NXT_STATEDIR \
 		|| install -d \$(DESTDIR)$NXT_STATEDIR
 	test -d \$(DESTDIR)$NXT_LOGDIR \
@@ -376,7 +371,8 @@ ${NXT_DAEMON}-install: $NXT_DAEMON install-check
 manpage-install: manpage install-check
 	test -d \$(DESTDIR)$NXT_MANDIR/man8 \
 		|| install -d \$(DESTDIR)$NXT_MANDIR/man8
-	install -p -m644 $NXT_BUILD_DIR/unitd.8 \$(DESTDIR)$NXT_MANDIR/man8/
+	install -p -m644 $NXT_BUILD_DIR/share/man/man8/unitd.8 \
+		\$(DESTDIR)$NXT_MANDIR/man8/
 
 .PHONY: uninstall ${NXT_DAEMON}-uninstall manpage-uninstall
 
@@ -396,10 +392,10 @@ cat << END >> $NXT_MAKEFILE
 
 .PHONY: libunit-install libunit-uninstall
 
-libunit-install: $NXT_BUILD_DIR/$NXT_LIB_UNIT_STATIC
+libunit-install: $NXT_BUILD_DIR/lib/$NXT_LIB_UNIT_STATIC
 	test -d \$(DESTDIR)$NXT_LIBDIR \
 		|| install -d \$(DESTDIR)$NXT_LIBDIR
-	install -p -m u=rw,go=r $NXT_BUILD_DIR/$NXT_LIB_UNIT_STATIC \
+	install -p -m u=rw,go=r $NXT_BUILD_DIR/lib/$NXT_LIB_UNIT_STATIC \
 		\$(DESTDIR)$NXT_LIBDIR/
 	test -d \$(DESTDIR)$NXT_INCLUDEDIR \
 		|| install -d \$(DESTDIR)$NXT_INCLUDEDIR
@@ -410,8 +406,8 @@ libunit-install: $NXT_BUILD_DIR/$NXT_LIB_UNIT_STATIC
 		src/nxt_unit_sptr.h \
 		src/nxt_unit_typedefs.h \
 		src/nxt_unit_websocket.h \
-		$NXT_BUILD_DIR/nxt_auto_config.h \
-		$NXT_BUILD_DIR/nxt_version.h \
+		$NXT_BUILD_DIR/include/nxt_auto_config.h \
+		$NXT_BUILD_DIR/include/nxt_version.h \
 		src/nxt_websocket_header.h \
 		\$(DESTDIR)$NXT_INCLUDEDIR/