tests: Improve llvm dependency test coverage

mesonbuild/dependencies/dev.py

@@ -202,6 +202,8 @@ class LLVMDependency(ExternalDependency):
                 out = out.strip()
                 if p.returncode != 0:
                     continue
+                # FIXME: As soon as some llvm-config is found, version checks
+                # in further dependnecy() calls will be ignored
                 if version_req:
                     if version_compare(out, version_req, strict=True):
                         if cls.__best_found and version_compare(out, '<={}'.format(cls.__best_found), strict=True):

run_unittests.py

@@ -1256,6 +1256,10 @@ class FailureTests(BasePlatformTests):
         for contents, match in a:
             self.assertMesonRaises(contents, match)
 
+    def test_llvm_dependency(self):
+        self.assertMesonRaises("dependency('llvm', modules : 'fail')",
+                               "(required.*fail|{})".format(self.dnf))
+
 
 class WindowsTests(BasePlatformTests):
     '''

test cases/frameworks/15 llvm/meson.build

@@ -7,4 +7,11 @@ llvm_dep = dependency(
   required : true,
 )
 
+d = dependency('llvm', modules : 'not-found', required : false)
+assert(d.found() == false, 'not-found llvm module found')
+
+# XXX: Version checks are broken, see FIXME in LLVMDependency
+#d = dependency('llvm', version : '<0.1', required : false)
+#assert(d.found() == false, 'ancient llvm module found')
+
 executable('sum', 'sum.c',  dependencies : llvm_dep)