Add class cmRST to do basic reStructuredText processing

Create a cmRST class to perform just enough reStructuredText processing
to support display of Help documents in human-readable text format.
This will be used to implement --help-* command-line options.

Support directives "include", "replace", "parsed-literal", "toctree"
(Sphinx), and "cmake-module" (CMake Sphinx Extension to scan .cmake
modules).  Support inline CMake Sphinx Domain roles to convert
cross-references to corresponding title text.  Support inline
substitutions defined by the "replace" directive, but keep it simple by
requiring replacements to be defined before use.

Add a CMakeLib "testRST" case to cover processing of supported
constructs and compare results against expected output.

1 files changed, 60 insertions, 0 deletions

diff --git a/Tests/CMakeLib/testRST.expect b/Tests/CMakeLib/testRST.expect
new file mode 100644
index 0000000..6a89002
--- /dev/null
+++ b/Tests/CMakeLib/testRST.expect
@@ -0,0 +1,60 @@
+title_text
+----------
+
+Command ``some_cmd()`` explicit cmake domain.
+Command ``some_cmd()`` without target.
+Command ``some_cmd`` with target.
+Command ``some_cmd_<cmd>()`` placeholder without target.
+Command ``some_cmd_<cmd>`` placholder with target.
+Command ``some_cmd()`` with parens.
+Command ``some_cmd(SUB)`` with subcommand.
+Command ``some_cmd(SUB)`` with subcommand and target.
+Command ``some_cmd (SUB)`` with space and subcommand and target.
+Command ``some command`` with space and target.
+Variable ``some variable`` space and target.
+Variable ``<PLACEHOLDER>_VARIABLE`` with leading placeholder.
+Variable ``VARIABLE_<PLACEHOLDER>`` with trailing placeholder.
+Variable ``<PLACEHOLDER>_VARIABLE`` with leading placeholder and target.
+Variable ``VARIABLE_<PLACEHOLDER>`` with trailing placeholder and target.
+Generator ``Some Generator`` with space.
+
+First TOC entry.
+
+|not replaced|
+Second TOC entry.
+
+CMake Module Content
+
+More CMake Module Content
+
+.. cmake:command:: some_cmd
+
+   Command some_cmd description.
+
+.. command:: other_cmd
+
+   Command other_cmd description.
+
+.. cmake:variable:: some_var
+
+   Variable some_var description.
+
+.. variable:: other_var
+
+   Variable other_var description.
+
+  Parsed-literal included without directive.
+ Common Indentation Removed
+
+ # Sample CMake code block
+ if(condition)
+   message(indented)
+ endif()
+
+substituted text with multiple lines becomes one line
+
+End of first include.
+
+Cross-include substitution text with ``some_cmd()`` reference.
+
+End of second include.