Help: Add `.. versionadded` directives to commands documentation

This change ony concerns directives that appear in the document body.

The guidelines for inserting version directives:

 * Baseline version is CMake 3.0, i.e. directives start at 3.1.
 * Always use `.. versionadded::` directive, avoid ad-hoc version
   references. Exception: policy pages.
 * For new command signatures, put `versionadded` on a separate line
   after the signature.
 * For a group of new signatures in a new document section,
   a single version note at the beginning of the section is sufficient.
 * For new options, put `versionadded` on a separate line before
   option description.
 * If all the option descriptions in the list are short one-liners,
   it's fine to put `versionadded` on the same line as the description.
 * If multiple option descriptions in close proximity would have
   the same ..versionadded directive, consider adding a single
   directive after the list, mentioning all added options.
 * For compact value lists and sub-option lists, put a single
  `versionadded` directive after the list mentioning all additions.
 * When a change is described in a single paragraph, put
   `versionadded` into that paragraph.
 * When only part of the paragraph has changed, separate the changed
   part if it doesn't break the flow. Otherwise, write a follow-up
   clarification paragraph and apply version directive to that.
 * When multiple version directives are close by, order earlier
   additions before later additions.
 * Indent related lists and code blocks to include them in the scope
   of `versionadded` directive.

Issue: #19715

1 files changed, 39 insertions, 25 deletions

diff --git a/Help/command/if.rst b/Help/command/if.rst
index be992df..3b01463 100644
--- a/Help/command/if.rst
+++ b/Help/command/if.rst
@@ -85,8 +85,9 @@ Possible conditions are:
  (in any directory).
 
 ``if(TEST test-name)``
- True if the given name is an existing test name created by the
- :command:`add_test` command.
+ .. versionadded:: 3.3
+  True if the given name is an existing test name created by the
+  :command:`add_test` command.
 
 ``if(EXISTS path-to-file-or-directory)``
  True if the named file or directory exists.  Behavior is well-defined
@@ -116,7 +117,9 @@ Possible conditions are:
 ``if(<variable|string> MATCHES regex)``
  True if the given string or variable's value matches the given regular
  condition.  See :ref:`Regex Specification` for regex format.
- ``()`` groups are captured in :variable:`CMAKE_MATCH_<n>` variables.
+
+ .. versionadded:: 3.9
+  ``()`` groups are captured in :variable:`CMAKE_MATCH_<n>` variables.
 
 ``if(<variable|string> LESS <variable|string>)``
  True if the given string or variable's value is a valid number and less
@@ -131,12 +134,14 @@ Possible conditions are:
  to that on the right.
 
 ``if(<variable|string> LESS_EQUAL <variable|string>)``
- True if the given string or variable's value is a valid number and less
- than or equal to that on the right.
+ .. versionadded:: 3.7
+  True if the given string or variable's value is a valid number and less
+  than or equal to that on the right.
 
 ``if(<variable|string> GREATER_EQUAL <variable|string>)``
- True if the given string or variable's value is a valid number and greater
- than or equal to that on the right.
+ .. versionadded:: 3.7
+  True if the given string or variable's value is a valid number and greater
+  than or equal to that on the right.
 
 ``if(<variable|string> STRLESS <variable|string>)``
  True if the given string or variable's value is lexicographically less
@@ -151,12 +156,14 @@ Possible conditions are:
  to the string or variable on the right.
 
 ``if(<variable|string> STRLESS_EQUAL <variable|string>)``
- True if the given string or variable's value is lexicographically less
- than or equal to the string or variable on the right.
+ .. versionadded:: 3.7
+  True if the given string or variable's value is lexicographically less
+  than or equal to the string or variable on the right.
 
 ``if(<variable|string> STRGREATER_EQUAL <variable|string>)``
- True if the given string or variable's value is lexicographically greater
- than or equal to the string or variable on the right.
+ .. versionadded:: 3.7
+  True if the given string or variable's value is lexicographically greater
+  than or equal to the string or variable on the right.
 
 ``if(<variable|string> VERSION_LESS <variable|string>)``
  Component-wise integer version number comparison (version format is
@@ -177,25 +184,31 @@ Possible conditions are:
  component effectively truncates the string at that point.
 
 ``if(<variable|string> VERSION_LESS_EQUAL <variable|string>)``
- Component-wise integer version number comparison (version format is
- ``major[.minor[.patch[.tweak]]]``, omitted components are treated as zero).
- Any non-integer version component or non-integer trailing part of a version
- component effectively truncates the string at that point.
+ .. versionadded:: 3.7
+  Component-wise integer version number comparison (version format is
+  ``major[.minor[.patch[.tweak]]]``, omitted components are treated as zero).
+  Any non-integer version component or non-integer trailing part of a version
+  component effectively truncates the string at that point.
 
 ``if(<variable|string> VERSION_GREATER_EQUAL <variable|string>)``
- Component-wise integer version number comparison (version format is
- ``major[.minor[.patch[.tweak]]]``, omitted components are treated as zero).
- Any non-integer version component or non-integer trailing part of a version
- component effectively truncates the string at that point.
+ .. versionadded:: 3.7
+  Component-wise integer version number comparison (version format is
+  ``major[.minor[.patch[.tweak]]]``, omitted components are treated as zero).
+  Any non-integer version component or non-integer trailing part of a version
+  component effectively truncates the string at that point.
 
 ``if(<variable|string> IN_LIST <variable>)``
- True if the given element is contained in the named list variable.
+ .. versionadded:: 3.3
+  True if the given element is contained in the named list variable.
 
 ``if(DEFINED <name>|CACHE{<name>}|ENV{<name>})``
  True if a variable, cache variable or environment variable
  with given ``<name>`` is defined. The value of the variable
  does not matter. Note that macro arguments are not variables.
 
+ .. versionadded:: 3.14
+  Added support for ``CACHE{<name>}`` variables.
+
 ``if((condition) AND (condition OR (condition)))``
  The conditions inside the parenthesis are evaluated first and then
  the remaining condition is evaluated as in the previous examples.
@@ -268,11 +281,12 @@ above-documented condition syntax accepts ``<variable|string>``:
   tested to see if they are boolean constants, if so they are used as
   such, otherwise they are assumed to be variables and are dereferenced.
 
-To prevent ambiguity, potential variable or keyword names can be
-specified in a :ref:`Quoted Argument` or a :ref:`Bracket Argument`.
-A quoted or bracketed variable or keyword will be interpreted as a
-string and not dereferenced or interpreted.
-See policy :policy:`CMP0054`.
+.. versionadded:: 3.1
+  To prevent ambiguity, potential variable or keyword names can be
+  specified in a :ref:`Quoted Argument` or a :ref:`Bracket Argument`.
+  A quoted or bracketed variable or keyword will be interpreted as a
+  string and not dereferenced or interpreted.
+  See policy :policy:`CMP0054`.
 
 There is no automatic evaluation for environment or cache
 :ref:`Variable References`.  Their values must be referenced as