From a3e20c8efdd85a18b29de839e38dfa3fc5cf46d3 Mon Sep 17 00:00:00 2001
From: Dave Abrahams <dave@boostpro.com>
Date: Wed, 21 Nov 2001 03:02:23 +0000
Subject: [PATCH] turn off incremental linking of DLLs, which was a major
 disaster for dependency tracking.

[SVN r11755]
---
 msvc-tools.jam    | 12 +++++++++++-
 v1/msvc-tools.jam | 12 +++++++++++-
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/msvc-tools.jam b/msvc-tools.jam
index d35bde2f5..7f352f289 100644
--- a/msvc-tools.jam
+++ b/msvc-tools.jam
@@ -56,11 +56,21 @@ flags msvc LINKFLAGS <target-type>DLL : /DLL ;
 rule Link-action
 {
     with-command-file msvc-Link-action $(<) : $(>) $(NEEDLIBS) ;
+    if $(<[2])
+    {
+        # incremental linking a DLL causes no end of problems: if the
+        # actual exports don't change, the import .lib file is never
+        # updated. Therefore, the .lib is always out-of-date and gets
+        # rebuilt every time. I'm not sure that incremental linking is
+        # such a great idea in general, but in this case I'm sure we
+        # don't want it.
+        NOINCREMENTAL on $(<) = /INCREMENTAL:NO ;
+    }
 }
 
 actions together msvc-Link-action bind NEEDLIBS
 {
-    $(MSVC_TOOL_PATH)link /nologo $(LINKFLAGS) /PDB:"$(<[1]:S=.pdb)" /out:"$(<[1])" /LIBPATH:$(LIBPATH) /LIBPATH:$(STDLIBPATH) "$(FINDLIBS)" @"$(>)"
+    $(MSVC_TOOL_PATH)link /nologo $(NOINCREMENTAL) $(LINKFLAGS) /PDB:"$(<[1]:S=.pdb)" /out:"$(<[1])" /LIBPATH:$(LIBPATH) /LIBPATH:$(STDLIBPATH) "$(FINDLIBS)" @"$(>)"
 }
 
 #### Cc #####
diff --git a/v1/msvc-tools.jam b/v1/msvc-tools.jam
index d35bde2f5..7f352f289 100644
--- a/v1/msvc-tools.jam
+++ b/v1/msvc-tools.jam
@@ -56,11 +56,21 @@ flags msvc LINKFLAGS <target-type>DLL : /DLL ;
 rule Link-action
 {
     with-command-file msvc-Link-action $(<) : $(>) $(NEEDLIBS) ;
+    if $(<[2])
+    {
+        # incremental linking a DLL causes no end of problems: if the
+        # actual exports don't change, the import .lib file is never
+        # updated. Therefore, the .lib is always out-of-date and gets
+        # rebuilt every time. I'm not sure that incremental linking is
+        # such a great idea in general, but in this case I'm sure we
+        # don't want it.
+        NOINCREMENTAL on $(<) = /INCREMENTAL:NO ;
+    }
 }
 
 actions together msvc-Link-action bind NEEDLIBS
 {
-    $(MSVC_TOOL_PATH)link /nologo $(LINKFLAGS) /PDB:"$(<[1]:S=.pdb)" /out:"$(<[1])" /LIBPATH:$(LIBPATH) /LIBPATH:$(STDLIBPATH) "$(FINDLIBS)" @"$(>)"
+    $(MSVC_TOOL_PATH)link /nologo $(NOINCREMENTAL) $(LINKFLAGS) /PDB:"$(<[1]:S=.pdb)" /out:"$(<[1])" /LIBPATH:$(LIBPATH) /LIBPATH:$(STDLIBPATH) "$(FINDLIBS)" @"$(>)"
 }
 
 #### Cc #####