Configure: shared sources for addon modules.

Addon modules, both dynamic and static, can now use shared source files.
Shared sources result in only one make rule even if specified several
times in different modules.

auto/make

diff --git a/auto/make b/auto/make
index 041d280..ef7c9f6 100644
--- a/auto/make
+++ b/auto/make
@@ -502,6 +502,7 @@
 for ngx_module in $DYNAMIC_MODULES
 do
     eval ngx_module_srcs="\$${ngx_module}_SRCS"
+    eval ngx_module_shrd="\$${ngx_module}_SHRD"
     eval eval ngx_module_libs="\\\"\$${ngx_module}_LIBS\\\""
 
     eval ngx_module_modules="\$${ngx_module}_MODULES"
@@ -567,7 +568,7 @@
         | sed -e "s/\(.*\.\)c/\1$ngx_objext/"`
 
     ngx_module_objs=
-    for ngx_src in $ngx_module_srcs
+    for ngx_src in $ngx_module_srcs $ngx_module_shrd
     do
         case "$ngx_src" in
             src/*)

auto/module

diff --git a/auto/module b/auto/module
index a2b578d..3857d04 100644
--- a/auto/module
+++ b/auto/module
@@ -17,7 +17,6 @@
     done
 
     DYNAMIC_MODULES="$DYNAMIC_MODULES $ngx_module"
-    eval ${ngx_module}_SRCS=\"$ngx_module_srcs\"
 
     eval ${ngx_module}_MODULES=\"$ngx_module_name\"
 
@@ -31,6 +30,30 @@
         eval ${ngx_module}_ORDER=\"$ngx_module_order\"
     fi
 
+    srcs=
+    shrd=
+    for src in $ngx_module_srcs
+    do
+        found=no
+        for old in $DYNAMIC_MODULES_SRCS
+        do
+            if [ $src = $old ]; then
+                found=yes
+                break
+            fi
+        done
+
+        if [ $found = no ]; then
+            srcs="$srcs $src"
+        else
+            shrd="$shrd $src"
+        fi
+    done
+    eval ${ngx_module}_SRCS=\"$srcs\"
+    eval ${ngx_module}_SHRD=\"$shrd\"
+
+    DYNAMIC_MODULES_SRCS="$DYNAMIC_MODULES_SRCS $srcs"
+
     if test -n "$ngx_module_incs"; then
         CORE_INCS="$CORE_INCS $ngx_module_incs"
     fi
@@ -107,7 +130,24 @@
     eval ${ngx_module_type}_MODULES=\"\$${ngx_module_type}_MODULES \
                                       $ngx_module_name\"
 
-    NGX_ADDON_SRCS="$NGX_ADDON_SRCS $ngx_module_srcs"
+    srcs=
+    for src in $ngx_module_srcs
+    do
+        found=no
+        for old in $NGX_ADDON_SRCS
+        do
+            if [ $src = $old ]; then
+                found=yes
+                break
+            fi
+        done
+
+        if [ $found = no ]; then
+            srcs="$srcs $src"
+        fi
+    done
+
+    NGX_ADDON_SRCS="$NGX_ADDON_SRCS $srcs"
 
     if test -n "$ngx_module_incs"; then
         eval ${ngx_var}_INCS=\"\$${ngx_var}_INCS $ngx_module_incs\"

auto/options

diff --git a/auto/options b/auto/options
index 110141d..80be906 100644
--- a/auto/options
+++ b/auto/options
@@ -132,6 +132,7 @@
 STREAM_SSL_PREREAD=NO
 
 DYNAMIC_MODULES=
+DYNAMIC_MODULES_SRCS=
 
 NGX_ADDONS=
 NGX_ADDON_SRCS=