Refactor Qt Dependency into proper split classes with factories

Currently the Qt Dependencies still use the old "combined" method for
dependencies with multiple ways to be found. This is problematic as it
means that `get_variable()` and friends don't work, as the dependency
can't implement any of those methods. The correct solution is to make
use of multiple Dependency instances, and a factory to tie them
together. This does that.

To handle QMake, I've leveraged the existing config-tool mechanism,
which allows us to save a good deal of code, and use well tested code
instead of rolling more of our own code.

The one thing this doesn't do, but we probably should, is expose the
macOS ExtraFrameworks directly, instead of forcing them to be found
through QMake. That is a problem for another series, and someone who
cares more about macOS than I do.

1 files changed, 11 insertions, 0 deletions

diff --git a/mesonbuild/dependencies/base.py b/mesonbuild/dependencies/base.py
index 6ec74ce..8944780 100644
--- a/mesonbuild/dependencies/base.py
+++ b/mesonbuild/dependencies/base.py
@@ -18,6 +18,7 @@ import copy
 import functools
 import os
 import re
+import itertools
 import json
 import shlex
 import shutil
@@ -136,11 +137,21 @@ class Dependency:
             return converted
         return self.compile_args
 
+    def get_all_compile_args(self) -> T.List[str]:
+        """Get the compile arguments from this dependency and it's sub dependencies."""
+        return list(itertools.chain(self.get_compile_args(),
+                                    *[d.get_all_compile_args() for d in self.ext_deps]))
+
     def get_link_args(self, raw: bool = False) -> T.List[str]:
         if raw and self.raw_link_args is not None:
             return self.raw_link_args
         return self.link_args
 
+    def get_all_link_args(self) -> T.List[str]:
+        """Get the link arguments from this dependency and it's sub dependencies."""
+        return list(itertools.chain(self.get_link_args(),
+                                    *[d.get_all_link_args() for d in self.ext_deps]))
+
     def found(self) -> bool:
         return self.is_found