Help: Add internal links to if() docs

Help/command/if.rst

@@ -39,13 +39,13 @@ the ``if``, ``elseif`` and :command:`while` clauses.
 
 Compound conditions are evaluated in the following order of precedence:
 Innermost parentheses are evaluated first. Next come unary tests such
-as ``EXISTS``, ``COMMAND``, and ``DEFINED``.  Then binary tests such as
-``EQUAL``, ``LESS``, ``LESS_EQUAL``, ``GREATER``, ``GREATER_EQUAL``,
-``STREQUAL``, ``STRLESS``, ``STRLESS_EQUAL``, ``STRGREATER``,
-``STRGREATER_EQUAL``, ``VERSION_EQUAL``, ``VERSION_LESS``,
-``VERSION_LESS_EQUAL``, ``VERSION_GREATER``, ``VERSION_GREATER_EQUAL``,
-and ``MATCHES``.  Then the boolean operators in the order ``NOT``,  ``AND``,
-and finally ``OR``.
+as `EXISTS`_, `COMMAND`_, and `DEFINED`_.  Then binary tests such as
+`EQUAL`_, `LESS`_, `LESS_EQUAL`_, `GREATER`_, `GREATER_EQUAL`_,
+`STREQUAL`_, `STRLESS`_, `STRLESS_EQUAL`_, `STRGREATER`_,
+`STRGREATER_EQUAL`_, `VERSION_EQUAL`_, `VERSION_LESS`_,
+`VERSION_LESS_EQUAL`_, `VERSION_GREATER`_, `VERSION_GREATER_EQUAL`_,
+and `MATCHES`_.  Then the boolean operators in the order `NOT`_,  `AND`_,
+and finally `OR`_.
 
 Basic Expressions
 """""""""""""""""
@@ -66,12 +66,18 @@ Basic Expressions
 Logic Operators
 """""""""""""""
 
+.. _NOT:
+
 ``if(NOT <condition>)``
  True if the condition is not true.
 
+.. _AND:
+
 ``if(<cond1> AND <cond2>)``
  True if both conditions would be considered true individually.
 
+.. _OR:
+
 ``if(<cond1> OR <cond2>)``
  True if either condition would be considered true individually.
 
@@ -84,6 +90,8 @@ Logic Operators
 Existence Checks
 """"""""""""""""
 
+.. _COMMAND:
+
 ``if(COMMAND command-name)``
  True if the given name is a command, macro or function that can be
  invoked.
@@ -102,6 +110,8 @@ Existence Checks
   True if the given name is an existing test name created by the
   :command:`add_test` command.
 
+.. _DEFINED:
+
 ``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
@@ -117,6 +127,8 @@ Existence Checks
 File Operations
 """""""""""""""
 
+.. _EXISTS:
+
 ``if(EXISTS path-to-file-or-directory)``
  True if the named file or directory exists.  Behavior is well-defined
  only for explicit full paths (a leading ``~/`` is not expanded as
@@ -146,6 +158,8 @@ File Operations
 Comparisons
 """""""""""
 
+.. _MATCHES:
+
 ``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.
@@ -153,45 +167,65 @@ Comparisons
  .. versionadded:: 3.9
   ``()`` groups are captured in :variable:`CMAKE_MATCH_<n>` variables.
 
+.. _LESS:
+
 ``if(<variable|string> LESS <variable|string>)``
  True if the given string or variable's value is a valid number and less
  than that on the right.
 
+.. _GREATER:
+
 ``if(<variable|string> GREATER <variable|string>)``
  True if the given string or variable's value is a valid number and greater
  than that on the right.
 
+.. _EQUAL:
+
 ``if(<variable|string> EQUAL <variable|string>)``
  True if the given string or variable's value is a valid number and equal
  to that on the right.
 
+.. _LESS_EQUAL:
+
 ``if(<variable|string> LESS_EQUAL <variable|string>)``
  .. 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.
 
+.. _GREATER_EQUAL:
+
 ``if(<variable|string> GREATER_EQUAL <variable|string>)``
  .. 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.
 
+.. _STRLESS:
+
 ``if(<variable|string> STRLESS <variable|string>)``
  True if the given string or variable's value is lexicographically less
  than the string or variable on the right.
 
+.. _STRGREATER:
+
 ``if(<variable|string> STRGREATER <variable|string>)``
  True if the given string or variable's value is lexicographically greater
  than the string or variable on the right.
 
+.. _STREQUAL:
+
 ``if(<variable|string> STREQUAL <variable|string>)``
  True if the given string or variable's value is lexicographically equal
  to the string or variable on the right.
 
+.. _STRLESS_EQUAL:
+
 ``if(<variable|string> STRLESS_EQUAL <variable|string>)``
  .. 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.
 
+.. _STRGREATER_EQUAL:
+
 ``if(<variable|string> STRGREATER_EQUAL <variable|string>)``
  .. versionadded:: 3.7
   True if the given string or variable's value is lexicographically greater
@@ -200,24 +234,32 @@ Comparisons
 Version Comparisons
 """""""""""""""""""
 
+.. _VERSION_LESS:
+
 ``if(<variable|string> VERSION_LESS <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.
 
+.. _VERSION_GREATER:
+
 ``if(<variable|string> VERSION_GREATER <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.
 
+.. _VERSION_EQUAL:
+
 ``if(<variable|string> VERSION_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.
 
+.. _VERSION_LESS_EQUAL:
+
 ``if(<variable|string> VERSION_LESS_EQUAL <variable|string>)``
  .. versionadded:: 3.7
   Component-wise integer version number comparison (version format is
@@ -225,6 +267,8 @@ Version Comparisons
   Any non-integer version component or non-integer trailing part of a version
   component effectively truncates the string at that point.
 
+.. _VERSION_GREATER_EQUAL:
+
 ``if(<variable|string> VERSION_GREATER_EQUAL <variable|string>)``
  .. versionadded:: 3.7
   Component-wise integer version number comparison (version format is