- Add comment explaining the reason for "touch" commands.

- Move "file-touch-command" to "common.jam". It already has
 "file-creation-command" so this one will be a good
  companion.

Patch from Alexey Pakhunov.


[SVN r32061]

v2/tools/common.jam

@@ -465,6 +465,22 @@ rule file-creation-command ( )
 }
 
         
+# Returns a command that may be used for 'touching' files.
+# It is not a real 'touch' command on NT because it adds an empty line at 
+# the end of file but it works with source files
+rule file-touch-command ( )
+{
+    if [ os.name ] in NT
+    {
+        return "echo. >> " ;
+    }
+    else
+    {
+        return "touch " ;
+    }
+}
+
+
 rule MkDir
 {
     # If dir exists, don't update it

v2/tools/midl.jam

@@ -128,22 +128,11 @@ flags midl.compile.idl INCLUDES <include> ;
 generators.register-c-compiler midl.compile.idl : IDL : MSTYPELIB H C(%_i) C(%_proxy) C(%_dlldata) ;
 
 
-# Returns a command that may be used for 'touching' files.
-# It is not a real 'touch' command on NT because it adds an empty line at 
-# the end of file but it works with source files
-rule file-touch-command ( )
-{
-    if [ os.name ] in NT
-    {
-        return "echo. >> " ;
-    }
-    else
-    {
-        return "touch " ;
-    }
-}
-
-TOUCH_FILE = [ file-touch-command ] ;
+# MIDL does not always generate '%_proxy.c' and '%_dlldata.c'. This behavior 
+# depends on contents of the source IDL file. Calling TOUCH_FILE below ensures
+# that both files will be created so bjam will not try to recreate them 
+# constantly.
+TOUCH_FILE = [ common.file-touch-command ] ;
 
 actions compile.idl
 {

v2/tools/msvc.jam

@@ -603,7 +603,8 @@ actions compile.rc
     $(.RC) -l 0x409 -U$(UNDEFS) -D$(DEFINES) -I"$(INCLUDES)" -fo "$(<:W)" "$(>:W)"
 }
 
-TOUCH_FILE = [ midl.file-touch-command ] ;
+# See midl.jam for details
+TOUCH_FILE = [ common.file-touch-command ] ;
 
 actions compile.idl
 {