Dynamic modules.

The auto/module script is extended to understand ngx_module_link=DYNAMIC.
When set, it links the module as a shared object rather than statically
into nginx binary.  The module can later be loaded using the "load_module"
directive.

New auto/module parameter ngx_module_order allows to define module loading
order in complex cases.  By default the order is set based on ngx_module_type.

3rd party modules can be compiled dynamically using the --add-dynamic-module
configure option, which will preset ngx_module_link to "DYNAMIC" before
calling the module config script.

Win32 support is rudimentary, and only works when using MinGW gcc (which
is able to handle exports/imports automatically).

In collaboration with Ruslan Ermilov.

auto/cc/conf

@@ -5,12 +5,17 @@
 
 LINK="\$(CC)"
 
+MAIN_LINK=
+MODULE_LINK="-shared"
+
 ngx_include_opt="-I "
 ngx_compile_opt="-c"
+ngx_pic_opt="-fPIC"
 ngx_objout="-o "
 ngx_binout="-o "
 ngx_objext="o"
 ngx_binext=
+ngx_modext=".so"
 
 ngx_long_start=
 ngx_long_end=
@@ -45,6 +50,9 @@ if test -n "$CFLAGS"; then
 
         sunc)
 
+            MAIN_LINK=
+            MODULE_LINK="-G"
+
             case "$NGX_MACHINE" in
 
                 i86pc)
@@ -156,6 +164,20 @@ if [ "$NGX_PLATFORM" != win32 ]; then
     fi
 
 
+    ngx_feature="-Wl,-E switch"
+    ngx_feature_name=
+    ngx_feature_run=no
+    ngx_feature_incs=
+    ngx_feature_path=
+    ngx_feature_libs=-Wl,-E
+    ngx_feature_test=
+    . auto/feature
+
+    if [ $ngx_found = yes ]; then
+        MAIN_LINK="-Wl,-E"
+    fi
+
+
     ngx_feature="gcc builtin atomic operations"
     ngx_feature_name=NGX_HAVE_GCC_ATOMIC
     ngx_feature_run=yes

auto/cc/msvc

@@ -118,6 +118,12 @@ NGX_RCC="rc -fo$NGX_RES \$(CORE_INCS) $NGX_WIN32_RC"
 CORE_LINK="$NGX_RES $CORE_LINK"
 
 
+# dynamic modules
+#MAIN_LINK="-link -def:$NGX_OBJS/nginx.def"
+#MODULE_LINK="-LD $NGX_OBJS/nginx.lib"
+
+
+ngx_pic_opt=
 ngx_objout="-Fo"
 ngx_binout="-Fe"
 ngx_objext="obj"

auto/cc/sunc

@@ -57,6 +57,9 @@ case "$NGX_MACHINE" in
 
 esac
 
+MAIN_LINK=
+MODULE_LINK="-G"
+
 
 # optimizations
 

auto/init

@@ -5,6 +5,7 @@
 
 NGX_MAKEFILE=$NGX_OBJS/Makefile
 NGX_MODULES_C=$NGX_OBJS/ngx_modules.c
+NGX_MODULES=
 
 NGX_AUTO_HEADERS_H=$NGX_OBJS/ngx_auto_headers.h
 NGX_AUTO_CONFIG_H=$NGX_OBJS/ngx_auto_config.h

auto/install

@@ -26,6 +26,18 @@ case ".$NGX_SBIN_PATH" in
 esac
 
 
+case ".$NGX_MODULES_PATH" in
+    ./*)
+    ;;
+
+    *)
+        NGX_MODULES_PATH=$NGX_PREFIX/$NGX_MODULES_PATH
+    ;;
+esac
+
+NGX_MODULES_PATH=`dirname $NGX_MODULES_PATH/.`
+
+
 case ".$NGX_CONF_PATH" in
     ./*)
     ;;
@@ -158,12 +170,24 @@ END
 fi
 
 
+if test -n "$NGX_MODULES"; then
+    cat << END                                                >> $NGX_MAKEFILE
+
+	test -d '\$(DESTDIR)$NGX_MODULES_PATH' \
+		|| mkdir -p '\$(DESTDIR)$NGX_MODULES_PATH'
+	cp $NGX_MODULES '\$(DESTDIR)$NGX_MODULES_PATH'
+END
+
+fi
+
+
 # create Makefile
 
 cat << END >> Makefile
 
 build:
 	\$(MAKE) -f $NGX_MAKEFILE
+	\$(MAKE) -f $NGX_MAKEFILE modules
 	\$(MAKE) -f $NGX_MAKEFILE manpage
 
 install:

auto/lib/conf

@@ -58,19 +58,19 @@ if [ $USE_ZLIB = YES ]; then
     . auto/lib/zlib/conf
 fi
 
-if [ $USE_LIBXSLT = YES ]; then
+if [ $USE_LIBXSLT != NO ]; then
     . auto/lib/libxslt/conf
 fi
 
-if [ $USE_LIBGD = YES ]; then
+if [ $USE_LIBGD != NO ]; then
     . auto/lib/libgd/conf
 fi
 
 if [ $USE_PERL = YES ]; then
     . auto/lib/perl/conf
 fi
 
-if [ $HTTP_GEOIP = YES ]; then
+if [ $USE_GEOIP != NO ]; then
     . auto/lib/geoip/conf
 fi
 

auto/lib/geoip/conf

@@ -67,7 +67,12 @@ fi
 if [ $ngx_found = yes ]; then
 
     CORE_INCS="$CORE_INCS $ngx_feature_path"
-    CORE_LIBS="$CORE_LIBS $ngx_feature_libs"
+
+    if [ $USE_GEOIP = YES ]; then
+        CORE_LIBS="$CORE_LIBS $ngx_feature_libs"
+    fi
+
+    NGX_LIB_GEOIP=$ngx_feature_libs
 
     if [ $NGX_IPV6 = YES ]; then
         ngx_feature="GeoIP IPv6 support"

auto/lib/libgd/conf

@@ -67,7 +67,12 @@ fi
 if [ $ngx_found = yes ]; then
 
     CORE_INCS="$CORE_INCS $ngx_feature_path"
-    CORE_LIBS="$CORE_LIBS $ngx_feature_libs"
+
+    if [ $USE_LIBGD = YES ]; then
+        CORE_LIBS="$CORE_LIBS $ngx_feature_libs"
+    fi
+
+    NGX_LIB_LIBGD=$ngx_feature_libs
 
 else
 

auto/lib/libxslt/conf

@@ -76,7 +76,12 @@ fi
 if [ $ngx_found = yes ]; then
 
     CORE_INCS="$CORE_INCS $ngx_feature_path"
-    CORE_LIBS="$CORE_LIBS $ngx_feature_libs"
+
+    if [ $USE_LIBXSLT = YES ]; then
+        CORE_LIBS="$CORE_LIBS $ngx_feature_libs"
+    fi
+
+    NGX_LIB_LIBXSLT=$ngx_feature_libs
 
 else
 
@@ -152,5 +157,9 @@ fi
 
 
 if [ $ngx_found = yes ]; then
-    CORE_LIBS="$CORE_LIBS -lexslt"
+    if [ $USE_LIBXSLT = YES ]; then
+        CORE_LIBS="$CORE_LIBS -lexslt"
+    fi
+
+    NGX_LIB_LIBXSLT="$NGX_LIB_LIBXSLT -lexslt"
 fi