diff --git a/mozilla/config/rules.mk b/mozilla/config/rules.mk
index 783e429b743..742125cc6ee 100644
--- a/mozilla/config/rules.mk
+++ b/mozilla/config/rules.mk
@@ -254,8 +254,12 @@ LIBOBJS			:= $(addsuffix \", $(LIBOBJS))
 endif
 
 ifndef MOZ_AUTO_DEPS
-ifneq (,$(OBJS)$(SIMPLE_PROGRAMS))
+ifneq (,$(OBJS)$(XPIDLSRCS)$(SDK_XPIDLSRCS)$(SIMPLE_PROGRAMS))
 MDDEPFILES		= $(addprefix $(MDDEPDIR)/,$(OBJS:.$(OBJ_SUFFIX)=.pp))
+ifndef NO_GEN_XPT
+MDDEPFILES		+= $(addprefix $(MDDEPDIR)/,$(XPIDLSRCS:.idl=.xpt)) \
+			   $(addprefix $(MDDEPDIR)/,$(SDK_XPIDLSRCS:.idl=.xpt))
+endif
 endif
 endif
 
@@ -359,7 +363,7 @@ HOST_PROGOBJS		= $(HOST_OBJS)
 endif
 
 # MAKE_DIRS: List of directories to build while looping over directories.
-ifneq (,$(OBJS)$(SIMPLE_PROGRAMS))
+ifneq (,$(OBJS)$(XPIDLSRCS)$(SDK_XPIDLSRCS)$(SIMPLE_PROGRAMS))
 MAKE_DIRS		+= $(MDDEPDIR)
 GARBAGE_DIRS		+= $(MDDEPDIR)
 endif
@@ -1318,7 +1322,7 @@ ifndef NO_GEN_XPT
 # into $(XPIDL_MODULE).xpt and export it to $(FINAL_TARGET)/components.
 $(XPIDL_GEN_DIR)/%.xpt: %.idl $(XPIDL_COMPILE) $(XPIDL_GEN_DIR)/.done
 	$(REPORT_BUILD)
-	$(ELOG) $(XPIDL_COMPILE) -m typelib -w -I $(IDL_DIR) -I$(srcdir) -o $(XPIDL_GEN_DIR)/$* $(_VPATH_SRCS)
+	$(ELOG) $(XPIDL_COMPILE) -m typelib -w -I $(IDL_DIR) -I$(srcdir) -e $@ -d $(MDDEPDIR)/$*.pp $(_VPATH_SRCS)
 
 # no need to link together if XPIDLSRCS contains only XPIDL_MODULE
 ifneq ($(XPIDL_MODULE).idl,$(strip $(XPIDLSRCS)))
@@ -1652,7 +1656,7 @@ $(MDDEPDIR)/%.pp: %.s
 	$(REPORT_BUILD)
 	@$(MAKE_DEPS_NOAUTO)
 
-ifneq (,$(OBJS)$(SIMPLE_PROGRAMS))
+ifneq (,$(OBJS)$(XPIDLSRCS)$(SDK_XPIDLSRCS)$(SIMPLE_PROGRAMS))
 depend:: $(SUBMAKEFILES) $(MAKE_DIRS) $(MDDEPFILES)
 else
 depend:: $(SUBMAKEFILES)
@@ -1679,7 +1683,7 @@ endif # COMPILER_DEPEND
 $(MDDEPDIR):
 	@if test ! -d $@; then echo Creating $@; rm -rf $@; mkdir $@; else true; fi
 
-ifneq (,$(OBJS)$(SIMPLE_PROGRAMS))
+ifneq (,$(OBJS)$(XPIDLSRCS)$(SDK_XPIDLSRCS)$(SIMPLE_PROGRAMS))
 MDDEPEND_FILES		:= $(strip $(wildcard $(MDDEPDIR)/*.pp))
 
 ifneq (,$(MDDEPEND_FILES))
diff --git a/mozilla/xpcom/typelib/xpidl/xpidl.c b/mozilla/xpcom/typelib/xpidl/xpidl.c
index 74f2e9ca1f4..3ed8e776cdc 100644
--- a/mozilla/xpcom/typelib/xpidl/xpidl.c
+++ b/mozilla/xpcom/typelib/xpidl/xpidl.c
@@ -65,13 +65,14 @@ gboolean enable_warnings            = FALSE;
 gboolean verbose_mode               = FALSE;
 gboolean emit_typelib_annotations   = FALSE;
 gboolean explicit_output_filename   = FALSE;
+FILE *deps = NULL;
 
 /* The following globals are explained in xpt_struct.h */
 PRUint8  major_version              = XPT_MAJOR_VERSION;
 PRUint8  minor_version              = XPT_MINOR_VERSION;
 
 static char xpidl_usage_str[] =
-"Usage: %s -m mode [-w] [-v] [-t version number]\n"
+"Usage: %s -m mode [-w] [-v] [-t version number] [-d filename.pp]\n"
 "          [-I path] [-o basename | -e filename.ext] filename.idl\n"
 "       -a emit annotations to typelib\n"
 "       -w turn on warnings (recommended)\n"
@@ -80,6 +81,7 @@ static char xpidl_usage_str[] =
 "       -I add entry to start of include path for ``#include \"nsIThing.idl\"''\n"
 "       -o use basename (e.g. ``/tmp/nsIThing'') for output\n"
 "       -e use explicit output filename\n"
+"       -d write dependencies (requires -e)\n"
 "       -m specify output mode:\n";
 
 static void
@@ -227,6 +229,21 @@ int main(int argc, char *argv[])
             file_basename = argv[++i];
             explicit_output_filename = TRUE;
             break;
+          case 'd':
+            if (!explicit_output_filename) {
+                fprintf(stderr, "ERROR: -d requires -e\n");
+                xpidl_usage(argc, argv);
+                return 1;
+            }
+            if (i == argc) {
+                fprintf(stderr, "ERROR: missing filename after -d\n");
+                xpidl_usage(argc, argv);
+                return 1;
+            }
+            deps = fopen(argv[++i], "w");
+            if (deps)
+                fprintf(deps, "%s:", file_basename);
+            break;
           case 'm':
             if (i + 1 == argc) {
                 fprintf(stderr, "ERROR: missing modename after -m\n");
@@ -268,8 +285,12 @@ int main(int argc, char *argv[])
      * Don't try to process multiple files, given that we don't handle -o
      * multiply.
      */
-    if (xpidl_process_idl(argv[i], inc_head, file_basename, mode))
-        return 0;
+    i = xpidl_process_idl(argv[i], inc_head, file_basename, mode);
 
-    return 1;
+    if (deps) {
+        fprintf(deps, "\n");
+        fclose(deps);
+    }
+
+    return !i;
 }
diff --git a/mozilla/xpcom/typelib/xpidl/xpidl.h b/mozilla/xpcom/typelib/xpidl/xpidl.h
index 5ba4a1de4ba..e6d0e54f373 100644
--- a/mozilla/xpcom/typelib/xpidl/xpidl.h
+++ b/mozilla/xpcom/typelib/xpidl/xpidl.h
@@ -85,6 +85,7 @@ extern gboolean enable_warnings;
 extern gboolean verbose_mode;
 extern gboolean emit_typelib_annotations;
 extern gboolean explicit_output_filename;
+extern FILE *deps;
 
 extern PRUint8  major_version;
 extern PRUint8  minor_version;
diff --git a/mozilla/xpcom/typelib/xpidl/xpidl_idl.c b/mozilla/xpcom/typelib/xpidl/xpidl_idl.c
index 7b2b18e1bb9..64a2dd6ec7c 100644
--- a/mozilla/xpcom/typelib/xpidl/xpidl_idl.c
+++ b/mozilla/xpcom/typelib/xpidl/xpidl_idl.c
@@ -125,29 +125,33 @@ typedef struct input_callback_state {
 } input_callback_state;
 
 static FILE *
-fopen_from_includes(const char *filename, const char *mode,
+fopen_from_includes(char **filename, const char *mode,
                     IncludePathEntry *include_path)
 {
     IncludePathEntry *current_path = include_path;
     char *pathname;
     FILE *inputfile;
-    if (!strcmp(filename, "-"))
+    if (!strcmp(*filename, "-"))
         return stdin;
 
-    if (filename[0] != '/') {
+    if ((*filename)[0] != '/') {
         while (current_path) {
             pathname = g_strdup_printf("%s" G_DIR_SEPARATOR_S "%s",
-                                       current_path->directory, filename);
+                                       current_path->directory, *filename);
             if (!pathname)
                 return NULL;
             inputfile = fopen(pathname, mode);
-            g_free(pathname);
-            if (inputfile)
+            if (inputfile) {
+                free(*filename);
+                *filename = xpidl_strdup(pathname);
+                g_free(pathname);
                 return inputfile;
+            }
+            g_free(pathname);
             current_path = current_path->next;
         }
     } else {
-        inputfile = fopen(filename, mode);
+        inputfile = fopen(*filename, mode);
         if (inputfile)
             return inputfile;
     }
@@ -159,7 +163,7 @@ extern FILE* mac_fopen(const char* filename, const char *mode);
 #endif
 
 static input_data *
-new_input_data(const char *filename, IncludePathEntry *include_path)
+new_input_data(char **filename, IncludePathEntry *include_path)
 {
     input_data *new_data;
     FILE *inputfile;
@@ -172,14 +176,14 @@ new_input_data(const char *filename, IncludePathEntry *include_path)
 
 #if defined(XP_MAC) && defined(XPIDL_PLUGIN)
     /* on Mac, fopen knows how to find files. */
-    inputfile = fopen(filename, "r");
+    inputfile = fopen(*filename, "r");
 #elif defined(XP_OS2) || defined(XP_WIN32)
     /*
      * if filename is fully qualified (starts with driver letter), then
      * just call fopen();  else, go with fopen_from_includes()
      */
     if( filename[1] == ':' )
-      inputfile = fopen(filename, "r");
+      inputfile = fopen(*filename, "r");
     else
       inputfile = fopen_from_includes(filename, "r", include_path);
 #else
@@ -243,11 +247,14 @@ new_input_data(const char *filename, IncludePathEntry *include_path)
     new_data->point = new_data->buf = buffer;
     new_data->max = buffer + offset;
     *new_data->max = '\0';
-    new_data->filename = xpidl_strdup(filename);
+    new_data->filename = *filename;
     /* libIDL expects the line number to be that of the *next* line */
     new_data->lineno = 2;
     new_data->next = NULL;
 
+    if (deps)
+        fprintf(deps, " \\\n\t%s", *filename);
+
     return new_data;
 }
 
@@ -412,7 +419,8 @@ NextIsInclude(input_callback_state *callback_state, char **startp,
         filename = xpidl_strdup(filename);
         g_hash_table_insert(callback_state->already_included,
                             filename, (void *)TRUE);
-        new_data = new_input_data(filename, callback_state->include_path);
+        filename = xpidl_strdup(filename);
+        new_data = new_input_data(&filename, callback_state->include_path);
         if (!new_data) {
             char *error_message;
             IDL_file_get(&scratch, (int *)&data->lineno);
@@ -422,6 +430,7 @@ NextIsInclude(input_callback_state *callback_state, char **startp,
             msg_callback(IDL_ERROR, 0,
                          data->lineno, scratch, error_message);
             g_free(error_message);
+            free(filename);
             return -1;
         }
 
@@ -484,10 +493,11 @@ input_callback(IDL_input_reason reason, union IDL_input_data *cb_data,
     input_data *new_data = NULL;
     unsigned int len, copy;
     int rv;
-    char *start;
+    char *start, *filename;
 
     switch(reason) {
       case IDL_INPUT_REASON_INIT:
+        filename = xpidl_strdup(cb_data->init.filename);
         if (data == NULL || data->next == NULL) {
             /*
              * This is the first file being processed.  As it's the target
@@ -503,15 +513,15 @@ input_callback(IDL_input_reason reason, union IDL_input_data *cb_data,
             first_entry.directory = callback_state->include_path->directory;
             first_entry.next = NULL;
 
-            new_data = new_input_data(cb_data->init.filename,
-                                               &first_entry);
+            new_data = new_input_data(&filename, &first_entry);
         } else {
-            new_data = new_input_data(cb_data->init.filename,
-                                               callback_state->include_path);
+            new_data = new_input_data(&filename, callback_state->include_path);
         }
 
-        if (!new_data)
+        if (!new_data) {
+            free(filename);
             return -1;
+        }
 
         IDL_file_set(new_data->filename, (int)new_data->lineno);
         callback_state->input_stack = new_data;