diff --git a/build/cl.py b/build/cl.py
index 00318ade63f2f..8d7c526047d4d 100644
--- a/build/cl.py
+++ b/build/cl.py
@@ -57,6 +57,7 @@ def InvokeClWithDependencyGeneration(cmdline):
     f = open(depstarget, "w")
     for dep in sorted(deps):
         print >>f, "%s: %s" % (target, dep)
+        print >>f, "%s:" % dep
 
 if __name__ == "__main__":
     InvokeClWithDependencyGeneration(sys.argv[1:])
diff --git a/config/expandlibs_exec.py b/config/expandlibs_exec.py
index e93564d781a15..2a3274d543018 100644
--- a/config/expandlibs_exec.py
+++ b/config/expandlibs_exec.py
@@ -329,6 +329,9 @@ def main():
     with open(options.depend, 'w') as depfile:
         depfile.write("%s : %s\n" % (options.target, ' '.join(dep for dep in deps if os.path.isfile(dep) and dep != options.target)))
 
+        for dep in deps:
+            if os.path.isfile(dep) and dep != options.target:
+                depfile.write("%s :\n" % dep)
 
 if __name__ == '__main__':
     main()
diff --git a/config/expandlibs_gen.py b/config/expandlibs_gen.py
index 4ece9d578816d..25962f60c943b 100644
--- a/config/expandlibs_gen.py
+++ b/config/expandlibs_gen.py
@@ -44,4 +44,7 @@ def generate(args):
     if options.depend:
         ensureParentDir(options.depend)
         with open(options.depend, 'w') as depfile:
-            depfile.write("%s : %s\n" % (options.output, ' '.join(ExpandLibsDeps(args))))
+            deps = ExpandLibsDeps(args)
+            depfile.write("%s : %s\n" % (options.output, ' '.join(deps)))
+            for dep in deps:
+                depfile.write("%s :\n" % dep)
diff --git a/config/rules.mk b/config/rules.mk
index b774958dd3277..b7ecd8fabae6c 100644
--- a/config/rules.mk
+++ b/config/rules.mk
@@ -987,17 +987,19 @@ define MAKE_DEPS_AUTO_CC
 if test -d $(@D); then \
 	echo "Building deps for $< using Sun Studio cc"; \
 	$(CC) $(COMPILE_CFLAGS) -xM  $< >$(_MDDEPFILE) ; \
+	$(PYTHON) $(topsrcdir)/build/unix/add_phony_targets.py $(_MDDEPFILE) ; \
 fi
 endef
 define MAKE_DEPS_AUTO_CXX
 if test -d $(@D); then \
 	echo "Building deps for $< using Sun Studio CC"; \
 	$(CXX) $(COMPILE_CXXFLAGS) -xM $< >$(_MDDEPFILE) ; \
+	$(PYTHON) $(topsrcdir)/build/unix/add_phony_targets.py $(_MDDEPFILE) ; \
 fi
 endef
 endif # Sun Studio on Solaris
 
-$(OBJS) $(HOST_OBJS): $(GLOBAL_DEPS)
+$(OBJS) $(HOST_OBJS) $(PROGOBJS) $(HOST_PROGOBJS): $(GLOBAL_DEPS)
 
 # Rules for building native targets must come first because of the host_ prefix
 $(HOST_COBJS): host_%.$(OBJ_SUFFIX): %.c
@@ -1614,14 +1616,11 @@ ifneq (,$(filter-out all chrome default export realchrome tools clean clobber cl
 MDDEPEND_FILES		:= $(strip $(wildcard $(foreach file,$(OBJS) $(PROGOBJS) $(HOST_OBJS) $(HOST_PROGOBJS) $(TARGETS) $(XPIDLSRCS:.idl=.h) $(XPIDLSRCS:.idl=.xpt),$(MDDEPDIR)/$(notdir $(file)).pp) $(addprefix $(MDDEPDIR)/,$(EXTRA_MDDEPEND_FILES))))
 
 ifneq (,$(MDDEPEND_FILES))
-# The script mddepend.pl checks the dependencies and writes to stdout
-# one rule to force out-of-date objects. For example,
-#   foo.o boo.o: FORCE
-# The script has an advantage over including the *.pp files directly
-# because it handles the case when header files are removed from the build.
-# 'make' would complain that there is no way to build missing headers.
-ALL_PP_RESULTS = $(shell $(PERL) $(BUILD_TOOLS)/mddepend.pl - $(MDDEPEND_FILES))
-$(eval $(ALL_PP_RESULTS))
+ifdef .PYMAKE
+includedeps $(MDDEPEND_FILES)
+else
+include $(MDDEPEND_FILES)
+endif
 endif
 
 endif
diff --git a/configure.in b/configure.in
index c350964f2ddf0..d288021d85996 100644
--- a/configure.in
+++ b/configure.in
@@ -7992,7 +7992,7 @@ dnl ========================================================
 MOZ_ARG_HEADER(Build dependencies)
 
 if test "$GNU_CC" -a "$GNU_CXX"; then
-  _DEPEND_CFLAGS='$(filter-out %/.pp,-MD -MF $(MDDEPDIR)/$(@F).pp)'
+  _DEPEND_CFLAGS='-MD -MP -MF $(MDDEPDIR)/$(@F).pp'
 dnl Sun Studio on Solaris use -xM instead of -MD, see config/rules.mk
 elif test "$SOLARIS_SUNPRO_CC"; then
   _DEPEND_CFLAGS=
diff --git a/js/src/build/cl.py b/js/src/build/cl.py
index 00318ade63f2f..8d7c526047d4d 100644
--- a/js/src/build/cl.py
+++ b/js/src/build/cl.py
@@ -57,6 +57,7 @@ def InvokeClWithDependencyGeneration(cmdline):
     f = open(depstarget, "w")
     for dep in sorted(deps):
         print >>f, "%s: %s" % (target, dep)
+        print >>f, "%s:" % dep
 
 if __name__ == "__main__":
     InvokeClWithDependencyGeneration(sys.argv[1:])
diff --git a/js/src/build/unix/mddepend.pl b/js/src/build/unix/mddepend.pl
deleted file mode 100644
index 231998fdffb84..0000000000000
--- a/js/src/build/unix/mddepend.pl
+++ /dev/null
@@ -1,139 +0,0 @@
-#!/usr/bin/env perl
-
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-# mddepend.pl - Reads in dependencies generated my -MD flag. Prints list
-#   of objects that need to be rebuilt. These can then be added to the
-#   PHONY target. Using this script copes with the problem of header
-#   files that have been removed from the build.
-#    
-# Usage:
-#   mddepend.pl <output_file> <dependency_files...>
-#
-# Send comments, improvements, bugs to Steve Lamm (slamm@netscape.com).
-
-use strict;
-
-use constant DEBUG => 0;
-
-my $outfile = shift @ARGV;
-my $silent = $ENV{MAKEFLAGS} =~ /^\w*s|\s-s/;
-
-my $line = '';
-my %alldeps;
-# Parse dependency files
-while (<>) {
-  s/\r?\n$//; # Handle both unix and DOS line endings
-  $line .= $_;
-  if ($line =~ /\\$/) {
-    chop $line;
-    next;
-  }
-
-  $line =~ s|\\|/|g;
-
-  my ($obj,$rest) = split /\s*:\s+/, $line, 2;
-  $line = '';
-  next if !$obj || !$rest;
-
-  my @deps = split /\s+/, $rest;
-  push @{$alldeps{$obj}}, @deps;
-  if (DEBUG >= 2) {
-    foreach my $dep (@deps) { print STDERR "add $obj $dep\n"; }
-  }
-}
-
-# Test dependencies
-my %modtimes; # cache
-my @objs;     # force rebuild on these
-OBJ_LOOP: foreach my $obj (keys %alldeps) {
-  my $mtime = (stat $obj)[9] or next;
-
-  my %not_in_cache;
-  my $deps = $alldeps{$obj};
-  foreach my $dep_file (@{$deps}) {
-    my $dep_mtime = $modtimes{$dep_file};
-    if (not defined $dep_mtime) {
-      print STDERR "Skipping $dep_file for $obj, will stat() later\n" if DEBUG >= 2;
-      $not_in_cache{$dep_file} = 1;
-      next;
-    }
-
-    print STDERR "Found $dep_file in cache\n" if DEBUG >= 2;
-
-    if ($dep_mtime > $mtime) {
-      print STDERR "$dep_file($dep_mtime) newer than $obj($mtime)\n" if DEBUG;
-    }
-    elsif ($dep_mtime == -1) {
-      print STDERR "Couldn't stat $dep_file for $obj\n" if DEBUG;
-    }
-    else {
-      print STDERR "$dep_file($dep_mtime) older than $obj($mtime)\n" if DEBUG >= 2;
-      next;
-    }
-
-    push @objs, $obj; # dependency is missing or newer
-    next OBJ_LOOP; # skip checking the rest of the dependencies
-  }
-
-  foreach my $dep_file (keys %not_in_cache) {
-    print STDERR "STAT $dep_file for $obj\n" if DEBUG >= 2;
-    my $dep_mtime = $modtimes{$dep_file} = (stat $dep_file)[9] || -1;
-
-    if ($dep_mtime > $mtime) {
-      print STDERR "$dep_file($dep_mtime) newer than $obj($mtime)\n" if DEBUG;
-    }
-    elsif ($dep_mtime == -1) {
-      print STDERR "Couldn't stat $dep_file for $obj\n" if DEBUG;
-    }
-    else {
-      print STDERR "$dep_file($dep_mtime) older than $obj($mtime)\n" if DEBUG >= 2;
-      next;
-    }
-
-    push @objs, $obj; # dependency is missing or newer
-    next OBJ_LOOP; # skip checking the rest of the dependencies
-  }
-
-  # If we get here it means nothing needs to be done for $obj
-}
-
-# Output objects to rebuild (if needed).
-if ($outfile eq '-') {
-    if (@objs) {
-	print "@objs: FORCE\n";
-    }
-} elsif (@objs) {
-  my $old_output;
-  my $new_output = "@objs: FORCE\n";
-
-  # Read in the current dependencies file.
-  open(OLD, "<$outfile")
-    and $old_output = <OLD>;
-  close(OLD);
-
-  # Only write out the dependencies if they are different.
-  if ($new_output ne $old_output) {
-    open(OUT, ">$outfile") and print OUT "$new_output";
-    print "Updating dependencies file, $outfile\n" unless $silent;
-    if (DEBUG) {
-      print "new: $new_output\n";
-      print "was: $old_output\n" if $old_output ne '';
-    }
-  }
-} elsif (-s $outfile) {
-  # Remove the old dependencies because all objects are up to date.
-  print "Removing old dependencies file, $outfile\n" unless $silent;
-
-  if (DEBUG) {
-    my $old_output;
-    open(OLD, "<$outfile")
-      and $old_output = <OLD>;
-    close(OLD);
-    print "was: $old_output\n";
-  }
-
-  unlink $outfile;
-}
diff --git a/js/src/config/expandlibs_exec.py b/js/src/config/expandlibs_exec.py
index e93564d781a15..2a3274d543018 100644
--- a/js/src/config/expandlibs_exec.py
+++ b/js/src/config/expandlibs_exec.py
@@ -329,6 +329,9 @@ def main():
     with open(options.depend, 'w') as depfile:
         depfile.write("%s : %s\n" % (options.target, ' '.join(dep for dep in deps if os.path.isfile(dep) and dep != options.target)))
 
+        for dep in deps:
+            if os.path.isfile(dep) and dep != options.target:
+                depfile.write("%s :\n" % dep)
 
 if __name__ == '__main__':
     main()
diff --git a/js/src/config/expandlibs_gen.py b/js/src/config/expandlibs_gen.py
index 4ece9d578816d..25962f60c943b 100644
--- a/js/src/config/expandlibs_gen.py
+++ b/js/src/config/expandlibs_gen.py
@@ -44,4 +44,7 @@ def generate(args):
     if options.depend:
         ensureParentDir(options.depend)
         with open(options.depend, 'w') as depfile:
-            depfile.write("%s : %s\n" % (options.output, ' '.join(ExpandLibsDeps(args))))
+            deps = ExpandLibsDeps(args)
+            depfile.write("%s : %s\n" % (options.output, ' '.join(deps)))
+            for dep in deps:
+                depfile.write("%s :\n" % dep)
diff --git a/js/src/config/rules.mk b/js/src/config/rules.mk
index b774958dd3277..b7ecd8fabae6c 100644
--- a/js/src/config/rules.mk
+++ b/js/src/config/rules.mk
@@ -987,17 +987,19 @@ define MAKE_DEPS_AUTO_CC
 if test -d $(@D); then \
 	echo "Building deps for $< using Sun Studio cc"; \
 	$(CC) $(COMPILE_CFLAGS) -xM  $< >$(_MDDEPFILE) ; \
+	$(PYTHON) $(topsrcdir)/build/unix/add_phony_targets.py $(_MDDEPFILE) ; \
 fi
 endef
 define MAKE_DEPS_AUTO_CXX
 if test -d $(@D); then \
 	echo "Building deps for $< using Sun Studio CC"; \
 	$(CXX) $(COMPILE_CXXFLAGS) -xM $< >$(_MDDEPFILE) ; \
+	$(PYTHON) $(topsrcdir)/build/unix/add_phony_targets.py $(_MDDEPFILE) ; \
 fi
 endef
 endif # Sun Studio on Solaris
 
-$(OBJS) $(HOST_OBJS): $(GLOBAL_DEPS)
+$(OBJS) $(HOST_OBJS) $(PROGOBJS) $(HOST_PROGOBJS): $(GLOBAL_DEPS)
 
 # Rules for building native targets must come first because of the host_ prefix
 $(HOST_COBJS): host_%.$(OBJ_SUFFIX): %.c
@@ -1614,14 +1616,11 @@ ifneq (,$(filter-out all chrome default export realchrome tools clean clobber cl
 MDDEPEND_FILES		:= $(strip $(wildcard $(foreach file,$(OBJS) $(PROGOBJS) $(HOST_OBJS) $(HOST_PROGOBJS) $(TARGETS) $(XPIDLSRCS:.idl=.h) $(XPIDLSRCS:.idl=.xpt),$(MDDEPDIR)/$(notdir $(file)).pp) $(addprefix $(MDDEPDIR)/,$(EXTRA_MDDEPEND_FILES))))
 
 ifneq (,$(MDDEPEND_FILES))
-# The script mddepend.pl checks the dependencies and writes to stdout
-# one rule to force out-of-date objects. For example,
-#   foo.o boo.o: FORCE
-# The script has an advantage over including the *.pp files directly
-# because it handles the case when header files are removed from the build.
-# 'make' would complain that there is no way to build missing headers.
-ALL_PP_RESULTS = $(shell $(PERL) $(BUILD_TOOLS)/mddepend.pl - $(MDDEPEND_FILES))
-$(eval $(ALL_PP_RESULTS))
+ifdef .PYMAKE
+includedeps $(MDDEPEND_FILES)
+else
+include $(MDDEPEND_FILES)
+endif
 endif
 
 endif
diff --git a/js/src/configure.in b/js/src/configure.in
index 52e943c20da70..b16f2576d57af 100644
--- a/js/src/configure.in
+++ b/js/src/configure.in
@@ -4020,7 +4020,7 @@ dnl ========================================================
 MOZ_ARG_HEADER(Build dependencies)
 
 if test "$GNU_CC" -a "$GNU_CXX"; then
-  _DEPEND_CFLAGS='$(filter-out %/.pp,-MD -MF $(MDDEPDIR)/$(@F).pp)'
+  _DEPEND_CFLAGS='-MD -MP -MF $(MDDEPDIR)/$(@F).pp'
 dnl Sun Studio on Solaris use -xM instead of -MD, see config/rules.mk
 elif test "$SOLARIS_SUNPRO_CC"; then
   _DEPEND_CFLAGS=
diff --git a/python/codegen/makeutils.py b/python/codegen/makeutils.py
index 91bb29427e751..f36a2ceeec0bc 100644
--- a/python/codegen/makeutils.py
+++ b/python/codegen/makeutils.py
@@ -26,7 +26,9 @@ def writeMakeDependOutput(filename):
             f.write("%s:" % makeQuote(targets[0]))
             for filename in dependencies:
                 f.write(' \\\n\t\t%s' % makeQuote(filename))
-            f.write('\n\n')
+            f.write('\n')
             for filename in targets[1:]:
                 f.write('%s: %s\n' % (makeQuote(filename), makeQuote(targets[0])))
+            for filename in dependencies:
+                f.write('%s:\n' % filename)
 
diff --git a/xpcom/idl-parser/header.py b/xpcom/idl-parser/header.py
index 2102ab02e0077..7725eeddee189 100644
--- a/xpcom/idl-parser/header.py
+++ b/xpcom/idl-parser/header.py
@@ -538,3 +538,5 @@ def emitTemplate(tmpl, tmpl_notxpcom=None):
         deps = [dep.replace('\\', '/') for dep in idl.deps]
 
         print >>depfd, "%s: %s" % (options.outfile, " ".join(deps))
+        for dep in deps:
+            print >>depfd, "%s:" % dep