Even though the `file(GLOB)` documentation specifically warns against
using it to collect a list of source files, projects often do it anyway.
Since it uses `readdir()`, the list of files will be unsorted.
This list is often passed directly to add_executable / add_library.
Linking binaries with an unsorted list will make it unreproducible,
which means that the produced binary will differ depending on the
unpredictable `readdir()` order.
To solve those reproducibility issues in a lot of programs (which don't
explicitly `list(SORT)` the list manually), sort the resulting list of
the `file(GLOB)` command.
A more detailed rationale about reproducible builds is available
[here](https://reproducible-builds.org/).
GLOB lists directories by default and GLOB_RECURSE does not.
LIST_DIRECTORIES enables user to control the behavior explicitly for
consistently for both GLOB and GLOB_RECURSE.
In commit v3.1.0-rc1~484^2 (Help: Format and revise file() command
documentation, 2014-05-23) the signature of file(GENERATE) was
accidentally simplified too much and dropped specification of the
required argument ordering. Restore the signature to make the order
clear.
Provide options to fail without blocking or to block up to a timeout.
Provide options to specify the scope containing the lock so it can be
released automatically at the end of a function, file, or process.
Extend the RunCMake.file test with cases covering the file(LOCK) command
usage and error cases.
Create a variable to allow users to control which installation
messages are printed. In particular, provide a "LAZY" setting
that prints "Installing" messages but not "Up-to-date" messages.
This is desirable for incremental re-installations.
Suggested-by: J Decker <d3ck0r@gmail.com>
Organize the documentation by sub-command to keep the signatures and
their descriptions nearby. Use inline and explicit reST markup. Revise
wording as necessary for the updated layout. Clarify behavior of the
file(GENERATE) command w.r.t. conflicting file names.