Fix virtual table construction

Functions are expected to have code_blockt values, don't do duplicate type
checking, parameters are in the symbol table already, don't use
code_function_callt.

Author: tautschnig

regression/cpp/virtual1/test.desc

@@ -1,4 +1,4 @@
-KNOWNBUG
+CORE
 main.cpp
 
 ^EXIT=0$

src/cpp/cpp_typecheck_compound_type.cpp

@@ -614,42 +614,33 @@ void cpp_typecheckt::typecheck_compound_declarator(
           lookup(args[0].get(ID_C_identifier)).symbol_expr(),
           to_code_type(component.type()).parameters()[0].type());
 
+        side_effect_expr_function_callt expr_call;
+        expr_call.function()=
+          symbol_exprt(component.get_name(), component.type());
+        expr_call.arguments().reserve(args.size());
+        expr_call.arguments().push_back(late_cast);
+
+        for(std::size_t i=1; i < args.size(); i++)
+        {
+          expr_call.arguments().push_back(
+            lookup(args[i].get(ID_C_identifier)).symbol_expr());
+        }
 
         if(code_type.return_type().id()!=ID_empty &&
            code_type.return_type().id()!=ID_destructor)
         {
-          side_effect_expr_function_callt expr_call;
-          expr_call.function()=
-            symbol_exprt(component.get_name(), component.type());
           expr_call.type()=to_code_type(component.type()).return_type();
-          expr_call.arguments().reserve(args.size());
-          expr_call.arguments().push_back(late_cast);
-
-          for(std::size_t i=1; i < args.size(); i++)
-          {
-            expr_call.arguments().push_back(
-              namespacet(symbol_table).lookup(
-                args[i].get(ID_C_identifier)).symbol_expr());
-          }
+          exprt already_typechecked(ID_already_typechecked);
+          already_typechecked.move_to_operands(expr_call);
 
-          func_symb.value=code_returnt(expr_call);
+          func_symb.value = code_returnt(already_typechecked).make_block();
         }
         else
         {
-          code_function_callt code_func;
-          code_func.function()=
-            symbol_exprt(component.get_name(), component.type());
-          code_func.arguments().reserve(args.size());
-          code_func.arguments().push_back(late_cast);
+          exprt already_typechecked(ID_already_typechecked);
+          already_typechecked.move_to_operands(expr_call);
 
-          for(std::size_t i=1; i < args.size(); i++)
-          {
-            code_func.arguments().push_back(
-              namespacet(symbol_table).lookup(
-                args[i].get(ID_C_identifier)).symbol_expr());
-          }
-
-          func_symb.value=code_func;
+          func_symb.value = code_expressiont(already_typechecked).make_block();
         }
 
         // add this new function to the list of components
@@ -665,6 +656,8 @@ void cpp_typecheckt::typecheck_compound_declarator(
           CHECK_RETURN(!failed);
         }
 
+        put_compound_into_scope(new_compo);
+
         // next base
         virtual_bases.erase(virtual_bases.begin());
       }

src/cpp/cpp_typecheck_function.cpp

@@ -34,6 +34,11 @@ void cpp_typecheckt::convert_parameter(
 
   parameter.set_identifier(identifier);
 
+  // the parameter may already have been set up if dealing with virtual methods
+  const symbolt *check_symbol;
+  if(!lookup(identifier, check_symbol))
+    return;
+
   symbolt symbol;
 
   symbol.name=identifier;
@@ -93,7 +98,13 @@ void cpp_typecheckt::convert_function(symbolt &symbol)
     assert(symbol.value.id()==ID_code);
     assert(symbol.value.get(ID_statement)==ID_block);
 
-    symbol.value.copy_to_operands(dtor(msymb));
+    if(
+      !symbol.value.has_operands() ||
+      !symbol.value.op0().has_operands() ||
+      symbol.value.op0().op0().id() != ID_already_typechecked)
+    {
+      symbol.value.copy_to_operands(dtor(msymb));
+    }
   }
 
   // enter appropriate scope