Merge topic 'dev/faster-evis'

90f66381 Help: Add release notes for policy CMP0053
6804cd04 Help: Add documentation on escaping changes with CMP0053
411f77d1 EVIS: Add tests for syntax corner cases and CMP0053
bc385658 EVIS: Reimplement using custom parsing code
25102efc EVIS: Add policy CMP0053
e423f1c0 Windows: Avoid () in environment variable references
c179b289 Help: Add more reference targets to cmake-language.7
c3d98bd2 Utilities/Release: Use ${VAR} instead of @VAR@ syntax

1 files changed, 17 insertions, 6 deletions

diff --git a/Help/manual/cmake-language.7.rst b/Help/manual/cmake-language.7.rst
index 1e4c6c5..b83dcad 100644
--- a/Help/manual/cmake-language.7.rst
+++ b/Help/manual/cmake-language.7.rst
@@ -287,6 +287,8 @@ For example:
  Instead use a `Quoted Argument`_ or a `Bracket Argument`_ to
  represent the content.
 
+.. _`Escape Sequences`:
+
 Escape Sequences
 ----------------
 
@@ -294,16 +296,20 @@ An *escape sequence* is a ``\`` followed by one character:
 
 .. productionlist::
  escape_sequence: `escape_identity` | `escape_encoded` | `escape_semicolon`
- escape_identity: '\(' | '\)' | '\#' | '\"' | '\ ' |
-                : '\\' | '\$' | '\@' | '\^'
+ escape_identity: '\' <match '[^A-Za-z0-9;]'>
  escape_encoded: '\t' | '\r' | '\n'
  escape_semicolon: '\;'
 
-A ``\`` followed by one of ``()#" \#@^`` simply encodes the literal
+A ``\`` followed by a non-alphanumeric character simply encodes the literal
 character without interpreting it as syntax.  A ``\t``, ``\r``, or ``\n``
-encodes a tab, carriage return, or newline character, respectively.
-A ``\;`` encodes itself but may be used in an `Unquoted Argument`_
-to encode the ``;`` without dividing the argument value on it.
+encodes a tab, carriage return, or newline character, respectively. A ``\;``
+outside of any `Variable References`_  encodes itself but may be used in an
+`Unquoted Argument`_ to encode the ``;`` without dividing the argument
+value on it.  A ``\;`` inside `Variable References`_ encodes the literal
+``;`` character.  (See also policy :policy:`CMP0053` documentation for
+historical considerations.)
+
+.. _`Variable References`:
 
 Variable References
 -------------------
@@ -315,6 +321,11 @@ or by the empty string if the variable is not set.
 Variable references can nest and are evaluated from the
 inside out, e.g. ``${outer_${inner_variable}_variable}``.
 
+Literal variable references may consist of alphanumeric characters,
+the characters ``/_.+-``, and `Escape Sequences`_.  Nested references
+may be used to evaluate variables of any name.  (See also policy
+:policy:`CMP0053` documentation for historical considerations.)
+
 The `Variables`_ section documents the scope of variable names
 and how their values are set.