[SV 63098] Temporarily revert the change to pattern rule behavior

The fix for SV 12078 caused a backward-compatibility issue with some
makefiles.  In order to allow users to resolve this issue, revert
that change for this release cycle: it will be reinstated in the
next release cycle.  Introduce a warning if we detect that the recipe
of a multi-target pattern rule doesn't create all the targets.

* NEWS: Announce the future backward-incompatibility.
* doc/make.texi (Pattern Intro): Describe the behavior and that it
will change in the future.
* src/remake.c (check_also_make): Check for also_make targets that
were not created and generate a warning.
(update_goal_chain): Call the new function.
(check_dep): Ditto.
(update_file_1): Defer implicit rule detection until after we check
all the also_make files (as it used to be).
* tests/scripts/features/patternrules: Add tests of the new warning.
Skip the tests for SV 12078.

1 files changed, 9 insertions, 0 deletions

diff --git a/doc/make.texi b/doc/make.texi
index 4bcd4fbe..79dc34dc 100644
--- a/doc/make.texi
+++ b/doc/make.texi
@@ -10623,6 +10623,15 @@ always treated as grouped targets (@pxref{Multiple Targets, , Multiple Targets
 in a Rule}) regardless of whether they use the @code{:} or @code{&:}
 separator.
 
+There is one exception: if a pattern target is out of date or does
+not exist and the makefile does not need to build it, then it will not cause
+the other targets to be considered out of date.  Note that this historical
+exception will be removed in future versions of GNU @code{make} and should not
+be relied on.  If this situation is detected @code{make} will generate a
+warning @emph{pattern recipe did not update peer target}; however, @code{make}
+cannot detect all such situations.  Please be sure that your recipe updates
+@emph{all} the target patterns when it runs.
+
 @node Pattern Examples, Automatic Variables, Pattern Intro, Pattern Rules
 @subsection Pattern Rule Examples