Support instantiating empty components

Author: kraigher

vhdl_lang/src/analysis/semantic.rs

@@ -200,6 +200,32 @@ impl<'a> AnalyzeContext<'a> {
                     None => {}
                 }
             }
+            ResolvedName::Final(ent) => {
+                if let AnyEntKind::Component(region) = ent.kind() {
+                    name.set_unique_reference(ent);
+                    let (generic_region, port_region) = region.to_entity_formal();
+                    self.analyze_assoc_elems_with_formal_region(
+                        &fcall.item.name.pos,
+                        &generic_region,
+                        scope,
+                        &mut [],
+                        diagnostics,
+                    )?;
+                    self.analyze_assoc_elems_with_formal_region(
+                        &fcall.item.name.pos,
+                        &port_region,
+                        scope,
+                        &mut [],
+                        diagnostics,
+                    )?;
+                } else {
+                    diagnostics.push(Diagnostic::error(
+                        &name.pos,
+                        format!("{} is not a procedure", resolved.describe_type()),
+                    ));
+                    self.analyze_assoc_elems(scope, parameters, diagnostics)?;
+                }
+            }
             resolved => {
                 diagnostics.push(Diagnostic::error(
                     &name.pos,

vhdl_lang/src/analysis/tests/resolves_design_units.rs

@@ -502,3 +502,33 @@ end architecture;
         )],
     );
 }
+
+#[test]
+fn empty_component_instantiation() {
+    let mut builder = LibraryBuilder::new();
+    let code = builder.code(
+        "libname",
+        "
+entity ent is
+end entity;
+
+architecture a of ent is
+    component empty
+    end component;
+begin
+    inst: empty;
+end architecture;
+
+
+",
+    );
+
+    let (root, diagnostics) = builder.get_analyzed_root();
+    check_no_diagnostics(&diagnostics);
+    assert_eq!(
+        root.search_reference(code.source(), code.sa("inst: ", "empty").start())
+            .unwrap()
+            .decl_pos(),
+        Some(&code.s1("empty").pos())
+    );
+}