Every policy's documentation has a paragraph on what version of CMake
introduced it, how to set the policy, and whether CMake warns if the
policy is not set. The wording of this paragraph has diverged across
policies over time. Factor the paragraph out into a standard advice
document included by every policy.
* The code snippets in the docs consist of CMake code mixed
with syntax definition punctuation like < > [ ] ... Therefore
a pure CMake lexer is inadequate. Here it is replaced by a
CMake syntax definition parser.
* Fixed syntax definition snippets in FindPkgConfig.cmake to
make best use of syntax highlighting. This source file is the
hardest to support because it contains comparison operators
<= = >=, which need special attention to avoid confusion
with the placeholder indicators <...>.
* Fixed syntax in execute_process.rst (there were unbalanced
brackets).
* Disabled syntax highlighting for long string examples in
cmake-language.7.rst.
* No highlighting of removed syntax in CMP0049
* To inspect the outcome of this patch, see e.g. the pages
* manual/cmake-buildsystem.7.html
* module/ExternalProject.html
* module/FindPkgConfig.html
which are particularly rich in complex code snippets.
The most likely documentation page a project author will read in
response to a policy warning is the page for the policy itself.
Add to every policy documentation page a note explicitly stating
that the OLD behavior is deprecated. Also mention this in the
cmake_policy() command documentation that explains how to set a
policy to OLD.
Suggested-by: Fraser Hutchison <fraser.hutchison@gmail.com>
Brad King