While we already support `cmake --build . -- -j`, the options after `--`
are specific to the native build tool. Add new options `--parallel
[<N>]` and `-j [<N>]` to abstract this and map to the proper option
for the native build tool.
Store both the as-written and lower-case command names and use
the latter to avoid case-insensitive string comparisons.
With this I obtain 2-6% speed increase (on Windows) for the configure
step with no significant changes in memory usage. A case-insensitive
comparison is a lot slower than just calling `==` because the operator
will use things like memcmp, so prefer the latter.
The `cmSystemTools::LowerCase` function allocates a new string each time
it is called, so before this change we were allocating in:
* cmMakefile::Configure two times for each function
(to look for `cmake_minimum_required` and `project`)
* cmMakefile::ExecuteCommand twice by function by calling
cmState::GetCommand and copying the name
Now we are only allocating once by function instead of four.
Similar to ECLIPSE_EXTRA_NATURES which can be used to add a third party
nature to the .project, this property offers the possibility to inject
third party contents into the .cproject.
An example of where this is useful is MCUXpresso. This is an IDE based
on Eclipse. Compiling through CMake generated Eclipse projects works
fine by using a custom toolchain. However, in order to be able to debug
using such a project, an extra storageModule specific to the target
board is needed in the cproject.
I have been hitting the Windows command-line limit when cross-compiling
static library (POCO) and having more than 8000 characters in the call
to "ar". Calculating exact limits here are tricky, since this particular
limit will only take into account object file strings, which is correct
for response files, but not for the archive rules (link.txt files),
since they also contain the call to "ar" and its arguments.
Also, there can be other additional arguments if "ar" tool is wrapped
into something else, so it is a good idea to leave more space than
trying to exactly fit the limit.
Since response files use half of the limit as a heuristic, we reproduce
it here for consistency.
Previously the command did not allow naming targets on the LHS that
were not created in the calling directory. Lift this restriction to
enable more flexible use by projects.
Fixes: #17943
Our custom command generation logic assumes that all command lines have
at least `argv0`. In `add_custom_{command,target}` we already check
that at least a `COMMAND` was given, but using `COMMAND_EXPAND_LISTS` in
combination with a generator expression that expands to an empty string
may produce an empty command line. In this case simply add an empty
string as a command to maintain our internal invariant.
Fixes: #17993
Le Minh PhucandChu Qinghao
Florian Maushart
Vitaly Stakhovsky
Brad King
Kitware Robot
Raul Laasner
Florian Jacomme
Marian Klymov
Melanie Cappelaere
Ruslan Baratov
Viktor Mukha
Patrick Stotko
Michael Stürmer