goto-programs: use new symbolt constructors

To the extent possible, apply resource-acquisition-is-initialisation.
The constructors ensure that at least the most essential fields (name,
type, mode) are set.

Author: tautschnig

src/goto-programs/builtin_functions.cpp

@@ -1480,10 +1480,8 @@ void goto_convertt::do_function_call_symbol(
 
     if(!symbol_table.has_symbol(name))
     {
-      symbolt new_symbol;
+      symbolt new_symbol{name, f_type, mode};
       new_symbol.base_name=name;
-      new_symbol.name=name;
-      new_symbol.type=f_type;
       new_symbol.location=function.source_location();
       symbol_table.add(new_symbol);
     }

src/goto-programs/goto_convert_exceptions.cpp

@@ -242,14 +242,10 @@ symbol_exprt goto_convertt::exception_flag(const irep_idt &mode)
 
   if(s_it==symbol_table.symbols.end())
   {
-    symbolt new_symbol;
+    symbolt new_symbol{id, bool_typet{}, mode};
     new_symbol.base_name="$exception_flag";
-    new_symbol.name=id;
     new_symbol.is_lvalue=true;
     new_symbol.is_thread_local=true;
-    new_symbol.is_file_local=false;
-    new_symbol.type=bool_typet();
-    new_symbol.mode = mode;
     symbol_table.insert(std::move(new_symbol));
   }
 

src/goto-programs/name_mangler.h

@@ -67,8 +67,7 @@ class function_name_manglert
         continue;
 
       const irep_idt mangled = mangle_fun(sym, extra_info);
-      symbolt new_sym;
-      new_sym = sym;
+      symbolt new_sym = sym;
       new_sym.name = mangled;
       new_sym.base_name = mangled;
       if(new_sym.pretty_name.empty())

src/goto-programs/string_instrumentation.cpp

@@ -732,26 +732,20 @@ void string_instrumentationt::do_strerror(
 
   if(symbol_table.symbols.find(identifier_buf)==symbol_table.symbols.end())
   {
-    symbolt new_symbol_size;
-    new_symbol_size.base_name="__strerror_buffer_size";
+    symbolt new_symbol_size{identifier_size, size_type(), ID_C};
+    new_symbol_size.base_name = identifier_size;
     new_symbol_size.pretty_name=new_symbol_size.base_name;
-    new_symbol_size.name=identifier_size;
-    new_symbol_size.mode=ID_C;
-    new_symbol_size.type=size_type();
     new_symbol_size.is_state_var=true;
     new_symbol_size.is_lvalue=true;
     new_symbol_size.is_static_lifetime=true;
 
     array_typet type(char_type(), new_symbol_size.symbol_expr());
-    symbolt new_symbol_buf;
-    new_symbol_buf.mode=ID_C;
-    new_symbol_buf.type=type;
+    symbolt new_symbol_buf{identifier_buf, type, ID_C};
     new_symbol_buf.is_state_var=true;
     new_symbol_buf.is_lvalue=true;
     new_symbol_buf.is_static_lifetime=true;
-    new_symbol_buf.base_name="__strerror_buffer";
+    new_symbol_buf.base_name = identifier_buf;
     new_symbol_buf.pretty_name=new_symbol_buf.base_name;
-    new_symbol_buf.name=new_symbol_buf.base_name;
 
     symbol_table.insert(std::move(new_symbol_buf));
     symbol_table.insert(std::move(new_symbol_size));
@@ -812,12 +806,9 @@ void string_instrumentationt::invalidate_buffer(
 
   if(symbol_table.symbols.find(cntr_id)==symbol_table.symbols.end())
   {
-    symbolt new_symbol;
+    symbolt new_symbol{cntr_id, size_type(), ID_C};
     new_symbol.base_name="$counter";
     new_symbol.pretty_name=new_symbol.base_name;
-    new_symbol.name=cntr_id;
-    new_symbol.mode=ID_C;
-    new_symbol.type=size_type();
     new_symbol.is_state_var=true;
     new_symbol.is_lvalue=true;
     new_symbol.is_static_lifetime=true;