Improve Windows diagnostics

[dirk-zimoch]

Starting with Visual Studio 2017, the MSVC compiler supports the option /diagnostics:caret (or -diagnostics:caret for those who abhor / options) which improves readability of errors and warnings by showing come context.

https://learn.microsoft.com/en-us/cpp/build/reference/diagnostics-compiler-diagnostic-options?view=msvc-170

It would be nice if that flag could be added automatically for all Visual Studio 2017+ ci builds.

[ralphlange]

That would be under the "verbose" option?
(So that it applies to building the main module, but not to building dependencies.)

[dirk-zimoch]

Building dependencies should never fail, right? And their warnings are their problem.
Actually, why not build dependencies with make -s ?

[ralphlange]

That is exactly what is done (unless you explicitly set something to verbose).
Thus my suggestion to not produce additional output that will be thrown away by make -s.

[dirk-zimoch]

Very good. Verbose option is it then.

[dirk-zimoch]

make -s does not throw away error output. It only throws away the command line echo.
But anyway, Error output of dependencies is their problem, not ours.

[anjohnson]

make -s silences our $(ECHO) commands as well, we have code that looks at $(MAKEFLAGS).