Helper for extracting function identifier

from a function call expression.

Author: petr-bauch

src/goto-programs/remove_function_pointers.cpp

@@ -174,6 +174,11 @@ class remove_function_pointerst
   void remove_function_pointer_log(
     goto_programt::targett target,
     const functionst &functions) const;
+
+  /// Extract function name from \p called_functions
+  /// \param: called_function: the function call expression
+  /// \return function identifier
+  irep_idt get_callee_id(const exprt &called_function) const;
 };
 
 remove_function_pointerst::remove_function_pointerst(
@@ -723,3 +728,40 @@ void remove_function_pointerst::remove_function_pointer_log(
       mstream << messaget::eom;
     });
 }
+
+irep_idt
+remove_function_pointerst::get_callee_id(const exprt &called_function) const
+{
+  irep_idt callee_id;
+  bool contains_code = false;
+  auto type_contains_code = [&contains_code](const typet &t) {
+    if(t.id() == ID_code)
+      contains_code = true;
+  };
+
+  called_function.visit_post(
+    [&callee_id, &type_contains_code, &contains_code](const exprt &e) {
+      if(e.id() == ID_symbol)
+      {
+        e.type().visit(type_contains_code);
+        if(contains_code)
+        {
+          callee_id = to_symbol_expr(e).get_identifier();
+          return;
+        }
+      }
+      if(e.id() == ID_dereference)
+      {
+        const auto &pointer = to_dereference_expr(e).pointer();
+        if(pointer.id() == ID_symbol)
+          callee_id = to_symbol_expr(pointer).get_identifier();
+        if(pointer.id() == ID_member)
+        {
+          pointer.type().visit(type_contains_code);
+          if(contains_code)
+            callee_id = to_member_expr(pointer).get_component_name();
+        }
+      }
+    });
+  return callee_id;
+}

src/util/type.h

@@ -139,6 +139,16 @@ class typet:public irept
 
     validate_type(type, ns, vm);
   }
+
+  void visit(std::function<void(const typet &)> f) const
+  {
+    f(*this);
+    for(const auto &sub_irep : get_sub())
+    {
+      const typet &subtype = static_cast<const typet &>(sub_irep);
+      subtype.visit(f);
+    }
+  }
 };
 
 /// Type with a single subtype.