better handling of unknown components in .init

src/ast/analysis/ComponentLookup.cpp

@@ -44,7 +44,6 @@ const Component* ComponentLookupAnalysis::getComponent(
     // forward according to binding (we do not do this recursively on purpose)
     QualifiedName boundName = activeBinding.find(name);
     if (boundName.empty()) {
-        // compName is not bound to anything => just just compName
         boundName = name;
     }
 

src/ast/transform/ComponentInstantiation.cpp

@@ -370,6 +370,8 @@ ComponentContent getInstantiatedContent(Program& program, const ComponentInit& c
 
     if (component == nullptr) {
         // this component is not defined => will trigger a semantic error
+        report.addError("Component " + componentInit.getComponentType()->getName() + " not found",
+                componentInit.getComponentType()->getSrcLoc());
         return res;
     }
 

tests/semantic/CMakeLists.txt

@@ -271,3 +271,4 @@ negative_test(error_deduce_type)
 positive_output_stdout_test(output_stdout)
 positive_test(iteration_counter)
 positive_test(issue1896)
+positive_test(comp_params)

tests/semantic/comp_params/TopA.Foo.X.x.csv

@@ -0,0 +1 @@
+A

tests/semantic/comp_params/TopB.Foo.X.x.csv

@@ -0,0 +1 @@
+B

tests/semantic/comp_params/comp_params.dl

@@ -0,0 +1,26 @@
+
+.comp A {
+  .decl x(s:symbol)
+  x("A").
+}
+
+.comp B {
+  .decl x(s:symbol)
+  x("B").
+}
+
+.comp _Top<Z> {
+
+  .comp _Foo<Z> : _Bar<Z> {
+  }
+
+  .comp _Bar<Q> {
+    .init X = Q
+    .output X.x()
+  }
+
+  .init Foo = _Foo<Z>
+}
+
+.init TopA = _Top<A>
+.init TopB = _Top<B>

tests/semantic/comp_params_inheritance/comp_params_inheritance.err

@@ -1,4 +1,4 @@
-Error: Undefined relation impl.R in file comp_params_inheritance.dl at line 10
-    Base(x) :- impl.R(x).
----------------^----------
+Error: Component T not found in file comp_params_inheritance.dl at line 8
+    .init impl = T
+-----------------^-
 1 errors generated, evaluation aborted