Compiled languages are Meson's bread and butter, but hardly required.
This is convenient, because many test caases specifically, do not care
about testing the compiler interactions.
In such cases, we can skip doing compiler lookups which aren't used, as
they only slow down test setup.
D lang compilers have an option -release (or similar) which turns off
asserts, contracts, and other runtime type checking. This patch wires
that up to the b_ndebug flag.
Fixes#7082
With the exception of things like sysconfdir (/etc), every other
installation directory option must be inside the prefix.
Also move the prefix checks to coredata.py since prefix can also be set
from inside project() with default_options and via mesonconf. Earlier
you could set prefix to a relative path that way.
This also allows us to return consistent values for get_option('xxxdir')
regardless of whether relative paths are passed or absolute paths are
passed while setting options on the command-line, via mesonconf, or via
default_options in project(). Now the returned path will *always* be
relative to the prefix.
Includes a unit test for this, and a failing test.
Closes#1299
Eli Schwartz
Jussi Pakkanen
Dylan Baker
Nirbheek Chauhan