Documentation updates in commit 02f527c66a (Find: Provide global
controls for the `NO_[]_PATH` call options, 2019-06-12,
v3.16.0-rc1~541^2) accidentally switched the `find_library`
documentation to mention `INCLUDE` where it should be `LIB`.
While at it, update `find_file` and `find_path` to mention
`INCLUDE` and `PATH` in the order they are considered.
This feature was originally added by commit v3.9.0-rc1~71^2~2 (find_*:
Add a new PackageRoot search path group, 2017-05-03) and documented by
commit v3.9.0-rc1~71^2 (find_*: Add docs for PackageRoot search path
group, 2017-05-03). However, we had to disable the feature and remove
the documentation in commit v3.9.1~2^2 (find_*: Disable the PACKAGE_ROOT
search path group for CMake 3.9, 2017-08-08) due to breaking projects
that used `PackageName_ROOT` variables themselves.
Add policy `CMP0074` to restore the `PackageName_ROOT` variable behavior
in a compatible way. Also revise the stack of root paths to store the
paths themselves rather than the package names. This way the policy can
be considered at the `find_package` call site instead of individual
`find_` calls inside a find module.
Co-Author: Chuck Atkins <chuck.atkins@kitware.com>
Issue: #17144
Disable the feature added by commit v3.9.0-rc1~71^2~2 (find_*: Add a new
PackageRoot search path group, 2017-05-03) and remove documentation
added by commit v3.9.0-rc1~71^2 (find_*: Add docs for PackageRoot search
path group, 2017-05-03). Unfortunately the name `<pkg>_ROOT` may
already be set by projects for their own incompatible purposes. Disable
the behavior change for now to fix the regression for CMake 3.9. We can
restore it later with a policy.
In order to keep the implementation and tests working, add an
undocumented variable we can use in the tests to enable the behavior
before the policy is introduced.
Fixes: #17144
Since commit v3.3.0-rc1~430^2 (Teach find_(library|file|path) to get
prefixes from PATH, 2015-02-18) we search in <prefix>/include and
<prefix>/lib directories for prefixes with bin directories in the PATH
environment variable. The motivation was to support MSYS, MinGW and
similar Windows platforms in their default environments automatically.
At the time this behavior was thought to be worthwhile in general.
Suggested-by: Chuck Atkins <chuck.atkins@kitware.com>
The find_package command already knows how to compute installation
prefixes from PATH. Use the same approach to establish prefixes for
find_library, find_file, and find_path to use to look in directories
like "<prefix>/lib[/<arch>]" and "<prefix>/include" for libraries and
headers. This will reduce the amount of configuration end users need to
do to establish a work environment rooted under a specific prefix.
These documents were represented in the builtin documentation using a
common starting point with placeholders substituted by each command.
Convert them back to this approach using the reStructuredText include
directive and substitutions to avoid duplication.
