From b754a35df7a5bd8bffd08fde0a7dfb599cbdc235 Mon Sep 17 00:00:00 2001
From: Paul Smith <psmith@gnu.org>
Date: Sun, 28 Feb 2016 12:35:15 -0500
Subject: [PATCH] * doc/make.texi: [SV 35455] Add more uses for Empty Recipes.
---
doc/make.texi | 33 +++++++++++++++------------------
1 file changed, 15 insertions(+), 18 deletions(-)
diff --git a/doc/make.texi b/doc/make.texi
index 86a1aebc..e8921713 100644
--- a/doc/make.texi
+++ b/doc/make.texi
@@ -4970,27 +4970,24 @@ beginning with a recipe prefix character to define an empty recipe,
but this would be confusing because such a line looks empty.
@findex .DEFAULT@r{, and empty recipes}
-You may be wondering why you would want to define a recipe that
-does nothing. The only reason this is useful is to prevent a target
-from getting implicit recipes (from implicit rules or the
-@code{.DEFAULT} special target; @pxref{Implicit Rules} and
-@pxref{Last Resort, ,Defining Last-Resort Default Rules}).@refill
+You may be wondering why you would want to define a recipe that does
+nothing. One reason this is useful is to prevent a target from
+getting implicit recipes (from implicit rules or the @code{.DEFAULT}
+special target; @pxref{Implicit Rules} and @pxref{Last Resort,
+,Defining Last-Resort Default Rules}).@refill
-@c !!! another reason is for canonical stamp files:
-@ignore
-@example
-foo: stamp-foo ;
-stamp-foo: foo.in
- create foo frm foo.in
- touch $@
-@end example
-@end ignore
+Empty recipes can also be used to avoid errors for targets that will
+be created as a side-effect of another recipe: if the target does not
+exist the empty recipe ensures that @code{make} won't complain that it
+doesn't know how to build the target, and @code{make} will assume the
+target is out of date.
-You may be inclined to define empty recipes for targets that are
-not actual files, but only exist so that their prerequisites can be
+You may be inclined to define empty recipes for targets that are not
+actual files, but only exist so that their prerequisites can be
remade. However, this is not the best way to do that, because the
-prerequisites may not be remade properly if the target file actually does exist.
-@xref{Phony Targets, ,Phony Targets}, for a better way to do this.
+prerequisites may not be remade properly if the target file actually
+does exist. @xref{Phony Targets, ,Phony Targets}, for a better way to
+do this.
@node Using Variables, Conditionals, Recipes, Top
@chapter How to Use Variables