sourceset: reinstate extra_deps

Dependencies in the "if_true" keyword argument do not prevent the
sources from being used; in other words, they work just like dependencies
with "disabler: false".

However, this was broken in commit ab0ffc6a2 ("modules/sourceset: Fix
remaining typing issues", 2022-02-23) which changed logic instead of
just fixing typing issues.  This was likely an attempt to avoid using
"dependencies.Dependency" after the "dependencies" field was declared,
but it also broke QEMU.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

mesonbuild/modules/sourceset.py

@@ -63,6 +63,7 @@ class SourceSetRule(T.NamedTuple):
     if_false: T.Any
     sourcesets: T.List[SourceSetImpl]
     deps: T.List[dependencies.Dependency]
+    extra_deps: T.List[dependencies.Dependency]
 
 
 class SourceFiles(T.NamedTuple):
@@ -159,7 +160,7 @@ class SourceSetImpl(SourceSet, MutableModuleObject):
         keys, dependencies = self.check_conditions(when)
         sources, extra_deps = self.check_source_files(if_true)
         if_false, _ = self.check_source_files(if_false)
-        self.rules.append(SourceSetRule(keys, sources, if_false, [], dependencies + extra_deps))
+        self.rules.append(SourceSetRule(keys, sources, if_false, [], dependencies, extra_deps))
 
     @typed_pos_args('sourceset.add_all', varargs=SourceSet)
     @typed_kwargs(
@@ -187,7 +188,7 @@ class SourceSetImpl(SourceSet, MutableModuleObject):
             if not isinstance(s, SourceSetImpl):
                 raise InvalidCode('Arguments to \'add_all\' after the first must be source sets')
             s.frozen = True
-        self.rules.append(SourceSetRule(keys, [], [], if_true, dependencies))
+        self.rules.append(SourceSetRule(keys, [], [], if_true, dependencies, []))
 
     def collect(self, enabled_fn: T.Callable[[str], bool],
                 all_sources: bool,
@@ -199,6 +200,7 @@ class SourceSetImpl(SourceSet, MutableModuleObject):
                all(enabled_fn(key) for key in entry.keys):
                 into.sources.update(entry.sources)
                 into.deps.update(entry.deps)
+                into.deps.update(entry.extra_deps)
                 for ss in entry.sourcesets:
                     ss.collect(enabled_fn, all_sources, into)
                 if not all_sources:

test cases/common/212 source set configuration_data/meson.build

@@ -8,7 +8,7 @@ source_set = import('sourceset')
 
 sources = source_set.source_set()
 sources.add(when: 'YES',  if_false: ['nope.c'])
-sources.add(when: 'YES1', if_true: files('a.c'))
+sources.add(when: 'YES1', if_true: [files('a.c'), not_found])
 subdir('subdir')
 sources.add(when: 'NO',   if_true: 'nope.c', if_false: ['f.c'])
 sources.add(when: 'NO',   if_true: bad,      if_false: ['f.c'])
@@ -24,7 +24,7 @@ sources2.add(when: 'YES1',  if_true: 'nope.c')
 sources.add_all(when: 'NO', if_true: sources2)
 
 # test duplicate items
-sources.add(when: 'YES1',   if_true: files('a.c'))
+sources.add(when: 'YES1',   if_true: [files('a.c'), not_found])
 
 conf1 = configuration_data()
 conf1.set10('YES', true)