find_*: Add support for option NO_CACHE

Request that find result is stored in a normal variable rather than a
cache entry.

Fixes: #20687
Issue: #20743

1 files changed, 19 insertions, 2 deletions

diff --git a/Help/command/FIND_XXX.txt b/Help/command/FIND_XXX.txt
index aae1c38..5b63e1c 100644
--- a/Help/command/FIND_XXX.txt
+++ b/Help/command/FIND_XXX.txt
@@ -15,6 +15,7 @@ The general signature is:
              [PATHS [path | ENV var]... ]
              [PATH_SUFFIXES suffix1 [suffix2 ...]]
              [DOC "cache documentation string"]
+             [NO_CACHE]
              [REQUIRED]
              [NO_DEFAULT_PATH]
              [NO_PACKAGE_ROOT_PATH]
@@ -28,8 +29,8 @@ The general signature is:
             )
 
 This command is used to find a |SEARCH_XXX_DESC|.
-A cache entry named by ``<VAR>`` is created to store the result
-of this command.
+A cache entry, or a normal variable if ``NO_CACHE`` is specified,
+named by ``<VAR>`` is created to store the result of this command.
 If the |SEARCH_XXX| is found the result is stored in the variable
 and the search will not be repeated unless the variable is cleared.
 If nothing is found, the result will be ``<VAR>-NOTFOUND``.
@@ -56,6 +57,22 @@ Options include:
 ``DOC``
   Specify the documentation string for the ``<VAR>`` cache entry.
 
+``NO_CACHE``
+  .. versionadded:: 3.21
+
+  The result of the search will be stored in a normal variable rather than
+  a cache entry.
+
+  .. note::
+
+    If the variable is already set before the call (as a normal or cache
+    variable) then the search will not occur.
+
+  .. warning::
+
+    This option should be used with caution because it can greatly increase
+    the cost of repeated configure steps.
+
 ``REQUIRED``
   .. versionadded:: 3.18