Restore "all" target in subdirectories marked EXCLUDE_FROM_ALL

The "all" target in each directory is supposed to have targets from that
directory even if the directory itself is marked `EXCLUDE_FROM_ALL` in
its parent.  This was broken by commit dc6888573d (Pass EXCLUDE_FROM_ALL
from directory to targets, 2019-01-15, v3.14.0-rc1~83^2) which made the
participation of a target in "all" independent of context.  Revert much
of the logic change from that commit to restore the old behavior.  Then
re-implement the behavior intended by the commit to keep its test
working.  Extend the test to cover the old behavior too.

Fixes: #19753

2 files changed, 17 insertions, 19 deletions

diff --git a/Help/prop_dir/EXCLUDE_FROM_ALL.rst b/Help/prop_dir/EXCLUDE_FROM_ALL.rst
index 9d3192c..8e3cca0 100644
--- a/Help/prop_dir/EXCLUDE_FROM_ALL.rst
+++ b/Help/prop_dir/EXCLUDE_FROM_ALL.rst
@@ -1,15 +1,13 @@
 EXCLUDE_FROM_ALL
 ----------------
 
-Exclude the directory from the all target of its parent.
+Set this directory property to a true value on a subdirectory to exclude
+its targets from the "all" target of its ancestors.  If excluded, running
+e.g. ``make`` in the parent directory will not build targets the
+subdirectory by default.  This does not affect the "all" target of the
+subdirectory itself.  Running e.g. ``make`` inside the subdirectory will
+still build its targets.
 
-A property on a directory that indicates if its targets are excluded
-from the default build target.  If it is not, then with a Makefile for
-example typing make will cause the targets to be built.  The same
-concept applies to the default build of other generators.
-
-Targets inherit the :prop_tgt:`EXCLUDE_FROM_ALL` property from the directory
-that they are created in. When a directory is excluded, all of its targets will
-have :prop_tgt:`EXCLUDE_FROM_ALL` set to ``TRUE``. After creating such a target
-you can change its :prop_tgt:`EXCLUDE_FROM_ALL` property to ``FALSE``. This
-will cause the target to be included in the default build target.
+If the :prop_tgt:`EXCLUDE_FROM_ALL` target property is set on a target
+then its value determines whether the target is included in the "all"
+target of this directory and its ancestors.
diff --git a/Help/prop_tgt/EXCLUDE_FROM_ALL.rst b/Help/prop_tgt/EXCLUDE_FROM_ALL.rst
index 0eee297..3aa296d 100644
--- a/Help/prop_tgt/EXCLUDE_FROM_ALL.rst
+++ b/Help/prop_tgt/EXCLUDE_FROM_ALL.rst
@@ -1,12 +1,15 @@
 EXCLUDE_FROM_ALL
 ----------------
 
-Exclude the target from the all target.
+Set this target property to a true (or false) value to exclude (or include)
+the target from the "all" target of the containing directory and its
+ancestors.  If excluded, running e.g. ``make`` in the containing directory
+or its ancestors will not build the target by default.
 
-A property on a target that indicates if the target is excluded from
-the default build target.  If it is not, then with a Makefile for
-example typing make will cause this target to be built.  The same
-concept applies to the default build of other generators.
+If this target property is not set then the target will be included in
+the "all" target of the containing directory.  Furthermore, it will be
+included in the "all" target of its ancestor directories unless the
+:prop_dir:`EXCLUDE_FROM_ALL` directory property is set.
 
 With ``EXCLUDE_FROM_ALL`` set to false or not set at all, the target
 will be brought up to date as part of doing a ``make install`` or its
@@ -16,6 +19,3 @@ target has undefined behavior.  Note that such a target can still safely
 be listed in an :command:`install(TARGETS)` command as long as the install
 components the target belongs to are not part of the set of components
 that anything tries to install.
-
-This property is enabled by default for targets that are created in
-directories that have :prop_dir:`EXCLUDE_FROM_ALL` set to ``TRUE``.