MSVC link /INCREMENTAL - does this actually work?

i've tried to get the MSVC 2008 linker to do incremental linking, see
the attached patch.

the linker is very picky and spits out an error message that it does a
full link if anything touches the .dll or .ilk file and modifies the
timestamp after it was linked.

but with the patch i don't get that error message for DLLs any more, but
still the linking does not seem to happen any faster.

i've tried in vcl and tookit modules, in an --enable-pch
--enable-dbgutil build, touch a single file and rebuild the module,
roughly as fast with incremental as without.

when i add -verbose to the linker options, i see what looks like
something adds additional parameters, among them a "/fullbuild" that is
documented nowhere apparently.  it's a mystery what is going on there.

maybe somebody more familiar with MSVC has some insight into this that
i'm missing (also i haven't got MSVC 2010 or 2012 installed so don't
know what happens there).

From 789f939ca4efea5544ede15667c2e4b4468bf424 Mon Sep 17 00:00:00 2001
From: Michael Stahl <mstahl@redhat.com>
Date: Mon, 8 Apr 2013 13:52:00 +0200
Subject: [PATCH] try -incremental

Change-Id: I5553248530d08af54f3aac4bd881f9c2af6e2a15
---
 solenv/gbuild/LinkTarget.mk             |    2 +-
 solenv/gbuild/platform/com_MSC_class.mk |    7 +++----
 2 files changed, 4 insertions(+), 5 deletions(-)
 mode change 100644 => 100755 solenv/gbuild/LinkTarget.mk

diff --git a/solenv/gbuild/LinkTarget.mk b/solenv/gbuild/LinkTarget.mk
old mode 100644
new mode 100755
index 46952c8..4825f21
--- a/solenv/gbuild/LinkTarget.mk
+++ b/solenv/gbuild/LinkTarget.mk
@@ -1179,7 +1179,7 @@ endef
 # gb_LinkTarget_add_auxtarget linktarget auxtarget
 define gb_LinkTarget_add_auxtarget
 $(2) : $(call gb_LinkTarget_get_target,$(1))
-       touch $$@
+       true
 
 $(call gb_LinkTarget_get_clean_target,$(1)) : AUXTARGETS += $(2)
 
diff --git a/solenv/gbuild/platform/com_MSC_class.mk b/solenv/gbuild/platform/com_MSC_class.mk
index 55aff01..8c10bf6 100755
--- a/solenv/gbuild/platform/com_MSC_class.mk
+++ b/solenv/gbuild/platform/com_MSC_class.mk
@@ -213,8 +213,6 @@ $(call gb_Helper_abbreviate_dirs,\
                $(if $(filter-out StaticLibrary,$(TARGETTYPE)),user32.lib) \
                $(if $(DLLTARGET),-out:$(DLLTARGET) -implib:$(1),-out:$(1)); RC=$$?; rm 
$${RESPONSEFILE} \
        $(if $(DLLTARGET),; if [ ! -f $(DLLTARGET) ]; then rm -f $(1) && false; fi) \
-       $(if $(filter Library,$(TARGETTYPE)),; if [ -f $(DLLTARGET).manifest ]; then mt.exe 
$(MTFLAGS) -nologo -manifest $(DLLTARGET).manifest -outputresource:$(DLLTARGET)\;2; fi) \
-       $(if $(filter Executable,$(TARGETTYPE)),; if [ -f $(1).manifest ]; then mt.exe $(MTFLAGS) 
-nologo -manifest $(1).manifest -outputresource:$(1)\;1; fi) \
        ; exit $$RC)
 endef
 
@@ -224,9 +222,10 @@ endef
 
 # Flags common for PE executables (EXEs and DLLs) 
 gb_Windows_PE_TARGETTYPEFLAGS := \
-       -release \
+       $(if $(gb_ENABLE_DBGUTIL),\
+               -incremental,\
+               -release -incremental:no) \
        -opt:noref \
-       -incremental:no \
        -debug \
        -nxcompat \
        -dynamicbase \
-- 
1.7.9