Merge pull request #8218 from tautschnig/cleanup/no-follow-ansi-c

C front-end: Replace uses of namespacet::follow

Author: kroening

src/ansi-c/anonymous_member.cpp

@@ -26,11 +26,10 @@ static member_exprt make_member_expr(
     result.set(ID_C_lvalue, true);
 
   // todo: should to typedef chains properly
-  const typet &type=
-    ns.follow(struct_union.type());
-
+  const auto &tag_type = to_struct_or_union_tag_type(struct_union.type());
   if(
-    type.get_bool(ID_C_constant) || struct_union.type().get_bool(ID_C_constant))
+    ns.follow_tag(tag_type).get_bool(ID_C_constant) ||
+    struct_union.type().get_bool(ID_C_constant))
   {
     result.type().set(ID_C_constant, true);
   }
@@ -43,13 +42,9 @@ exprt get_component_rec(
   const irep_idt &component_name,
   const namespacet &ns)
 {
-  const struct_union_typet &struct_union_type=
-    to_struct_union_type(ns.follow(struct_union.type()));
-
-  const struct_union_typet::componentst &components=
-    struct_union_type.components();
+  const auto &tag_type = to_struct_or_union_tag_type(struct_union.type());
 
-  for(const auto &comp : components)
+  for(const auto &comp : ns.follow_tag(tag_type).components())
   {
     const typet &type = comp.type();
 
@@ -76,13 +71,9 @@ bool has_component_rec(
   const irep_idt &component_name,
   const namespacet &ns)
 {
-  const struct_union_typet &struct_union_type=
-    to_struct_union_type(ns.follow(type));
-
-  const struct_union_typet::componentst &components=
-    struct_union_type.components();
+  const auto &tag_type = to_struct_or_union_tag_type(type);
 
-  for(const auto &comp : components)
+  for(const auto &comp : ns.follow_tag(tag_type).components())
   {
     if(comp.get_name()==component_name)
     {

src/ansi-c/c_typecast.cpp

@@ -289,9 +289,17 @@ typet c_typecastt::follow_with_qualifiers(const typet &src_type)
   // collect qualifiers
   c_qualifierst qualifiers(src_type);
 
-  while(result_type.id() == ID_struct_tag || result_type.id() == ID_union_tag)
+  if(
+    auto struct_tag_type = type_try_dynamic_cast<struct_tag_typet>(result_type))
+  {
+    const typet &followed_type = ns.follow_tag(*struct_tag_type);
+    result_type = followed_type;
+    qualifiers += c_qualifierst(followed_type);
+  }
+  else if(
+    auto union_tag_type = type_try_dynamic_cast<union_tag_typet>(result_type))
   {
-    const typet &followed_type = ns.follow(result_type);
+    const typet &followed_type = ns.follow_tag(*union_tag_type);
     result_type = followed_type;
     qualifiers += c_qualifierst(followed_type);
   }

src/ansi-c/c_typecheck_base.cpp

@@ -53,8 +53,6 @@ void c_typecheck_baset::typecheck_symbol(symbolt &symbol)
 {
   bool is_function=symbol.type.id()==ID_code;
 
-  const typet &final_type=follow(symbol.type);
-
   // set a few flags
   symbol.is_lvalue=!symbol.is_type && !symbol.is_macro;
 
@@ -91,15 +89,15 @@ void c_typecheck_baset::typecheck_symbol(symbolt &symbol)
   }
 
   // set the pretty name
-  if(symbol.is_type && final_type.id() == ID_struct)
+  if(symbol.is_type && symbol.type.id() == ID_struct)
   {
     symbol.pretty_name="struct "+id2string(symbol.base_name);
   }
-  else if(symbol.is_type && final_type.id() == ID_union)
+  else if(symbol.is_type && symbol.type.id() == ID_union)
   {
     symbol.pretty_name="union "+id2string(symbol.base_name);
   }
-  else if(symbol.is_type && final_type.id() == ID_c_enum)
+  else if(symbol.is_type && symbol.type.id() == ID_c_enum)
   {
     symbol.pretty_name="enum "+id2string(symbol.base_name);
   }
@@ -191,8 +189,8 @@ void c_typecheck_baset::typecheck_redefinition_type(
   symbolt &old_symbol,
   symbolt &new_symbol)
 {
-  const typet &final_old=follow(old_symbol.type);
-  const typet &final_new=follow(new_symbol.type);
+  const typet &final_old = old_symbol.type;
+  const typet &final_new = new_symbol.type;
 
   // see if we had something incomplete before
   if(
@@ -260,16 +258,16 @@ void c_typecheck_baset::typecheck_redefinition_type(
     else if(
       config.ansi_c.os == configt::ansi_ct::ost::OS_WIN &&
       final_new.id() == ID_pointer && final_old.id() == ID_pointer &&
-      follow(to_pointer_type(final_new).base_type()).id() == ID_c_enum &&
-      follow(to_pointer_type(final_old).base_type()).id() == ID_c_enum)
+      to_pointer_type(final_new).base_type().id() == ID_c_enum &&
+      to_pointer_type(final_old).base_type().id() == ID_c_enum)
     {
       // under Windows, ignore this silently;
       // MSC doesn't think this is a problem, but GCC complains.
     }
     else
     {
       // see if it changed
-      if(follow(new_symbol.type)!=follow(old_symbol.type))
+      if(new_symbol.type != old_symbol.type)
       {
         error().source_location=new_symbol.location;
         error() << "type symbol '" << new_symbol.display_name()
@@ -321,8 +319,8 @@ void c_typecheck_baset::typecheck_redefinition_non_type(
   symbolt &old_symbol,
   symbolt &new_symbol)
 {
-  const typet &final_old=follow(old_symbol.type);
-  const typet &initial_new=follow(new_symbol.type);
+  const typet &final_old = old_symbol.type;
+  const typet &initial_new = new_symbol.type;
 
   if(
     final_old.id() == ID_array &&
@@ -351,7 +349,7 @@ void c_typecheck_baset::typecheck_redefinition_non_type(
   if(new_symbol.type.id() != ID_code && !new_symbol.is_macro)
     do_initializer(new_symbol);
 
-  const typet &final_new=follow(new_symbol.type);
+  const typet &final_new = new_symbol.type;
 
   // K&R stuff?
   if(old_symbol.type.id()==ID_KnR)
@@ -548,9 +546,10 @@ void c_typecheck_baset::typecheck_redefinition_non_type(
       // int (*f) ();
     }
     else if(
-      final_old.id() == ID_struct && final_new.id() == ID_struct &&
+      final_old.id() == ID_struct_tag && final_new.id() == ID_struct_tag &&
       is_instantiation_of_flexible_array(
-        to_struct_type(final_old), to_struct_type(final_new)))
+        follow_tag(to_struct_tag_type(final_old)),
+        follow_tag(to_struct_tag_type(final_new))))
     {
       old_symbol.type = new_symbol.type;
     }

src/ansi-c/c_typecheck_code.cpp

@@ -387,9 +387,13 @@ bool c_typecheck_baset::is_complete_type(const typet &type) const
   }
   else if(type.id()==ID_vector)
     return is_complete_type(to_vector_type(type).element_type());
-  else if(type.id() == ID_struct_tag || type.id() == ID_union_tag)
+  else if(auto struct_tag_type = type_try_dynamic_cast<struct_tag_typet>(type))
   {
-    return is_complete_type(follow(type));
+    return is_complete_type(follow_tag(*struct_tag_type));
+  }
+  else if(auto union_tag_type = type_try_dynamic_cast<union_tag_typet>(type))
+  {
+    return is_complete_type(follow_tag(*union_tag_type));
   }
 
   return true;

src/ansi-c/c_typecheck_expr.cpp

@@ -451,14 +451,13 @@ void c_typecheck_baset::typecheck_expr_main(exprt &expr)
     exprt default_match=nil_exprt();
     exprt assoc_match=nil_exprt();
 
-    const typet &op_type = follow(op.type());
+    const typet &op_type = op.type();
 
     for(const auto &irep : generic_associations)
     {
       if(irep.get(ID_type_arg) == ID_default)
         default_match = static_cast<const exprt &>(irep.find(ID_value));
-      else if(
-        op_type == follow(static_cast<const typet &>(irep.find(ID_type_arg))))
+      else if(op_type == static_cast<const typet &>(irep.find(ID_type_arg)))
       {
         assoc_match = static_cast<const exprt &>(irep.find(ID_value));
       }
@@ -590,11 +589,9 @@ void c_typecheck_baset::typecheck_expr_builtin_offsetof(exprt &expr)
 
   for(const auto &op : member.operands())
   {
-    type = follow(type);
-
     if(op.id() == ID_member)
     {
-      if(type.id()!=ID_union && type.id()!=ID_struct)
+      if(type.id() != ID_union_tag && type.id() != ID_struct_tag)
       {
         error().source_location = expr.source_location();
         error() << "offsetof of member expects struct/union type, "
@@ -607,20 +604,20 @@ void c_typecheck_baset::typecheck_expr_builtin_offsetof(exprt &expr)
 
       while(!found)
       {
-        PRECONDITION(type.id() == ID_union || type.id() == ID_struct);
+        PRECONDITION(type.id() == ID_union_tag || type.id() == ID_struct_tag);
 
-        const struct_union_typet &struct_union_type=
-          to_struct_union_type(type);
+        const struct_union_typet &struct_union_type =
+          follow_tag(to_struct_or_union_tag_type(type));
 
         // direct member?
         if(struct_union_type.has_component(component_name))
         {
           found=true;
 
-          if(type.id()==ID_struct)
+          if(type.id() == ID_struct_tag)
           {
-            auto o_opt =
-              member_offset_expr(to_struct_type(type), component_name, *this);
+            auto o_opt = member_offset_expr(
+              follow_tag(to_struct_tag_type(type)), component_name, *this);
 
             if(!o_opt.has_value())
             {
@@ -650,10 +647,10 @@ void c_typecheck_baset::typecheck_expr_builtin_offsetof(exprt &expr)
             {
               if(has_component_rec(c.type(), component_name, *this))
               {
-                if(type.id()==ID_struct)
+                if(type.id() == ID_struct_tag)
                 {
                   auto o_opt = member_offset_expr(
-                    to_struct_type(type), c.get_name(), *this);
+                    follow_tag(to_struct_tag_type(type)), c.get_name(), *this);
 
                   if(!o_opt.has_value())
                   {
@@ -669,9 +666,10 @@ void c_typecheck_baset::typecheck_expr_builtin_offsetof(exprt &expr)
                       o_opt.value(), size_type()));
                 }
 
-                typet tmp = follow(c.type());
+                typet tmp = c.type();
                 type=tmp;
-                CHECK_RETURN(type.id() == ID_union || type.id() == ID_struct);
+                CHECK_RETURN(
+                  type.id() == ID_union_tag || type.id() == ID_struct_tag);
                 found2=true;
                 break; // we run into another iteration of the outer loop
               }
@@ -1377,7 +1375,7 @@ void c_typecheck_baset::typecheck_expr_rel(
 
   if(expr.id()==ID_equal || expr.id()==ID_notequal)
   {
-    if(follow(o_type0)==follow(o_type1))
+    if(o_type0 == o_type1)
     {
       if(o_type0.id() != ID_array)
       {
@@ -1530,10 +1528,7 @@ void c_typecheck_baset::typecheck_expr_member(exprt &expr)
   exprt &op0 = to_unary_expr(expr).op();
   typet type=op0.type();
 
-  type = follow(type);
-
-  if(type.id()!=ID_struct &&
-     type.id()!=ID_union)
+  if(type.id() != ID_struct_tag && type.id() != ID_union_tag)
   {
     error().source_location = expr.source_location();
     error() << "member operator requires structure type "
@@ -1542,8 +1537,8 @@ void c_typecheck_baset::typecheck_expr_member(exprt &expr)
     throw 0;
   }
 
-  const struct_union_typet &struct_union_type=
-    to_struct_union_type(type);
+  const struct_union_typet &struct_union_type =
+    follow_tag(to_struct_or_union_tag_type(type));
 
   if(struct_union_type.is_incomplete())
   {
@@ -1585,8 +1580,12 @@ void c_typecheck_baset::typecheck_expr_member(exprt &expr)
   if(op0.get_bool(ID_C_lvalue))
     expr.set(ID_C_lvalue, true);
 
-  if(op0.type().get_bool(ID_C_constant) || type.get_bool(ID_C_constant))
+  if(
+    op0.type().get_bool(ID_C_constant) ||
+    struct_union_type.get_bool(ID_C_constant))
+  {
     expr.type().set(ID_C_constant, true);
+  }
 
   // copy method identifier
   const irep_idt &identifier=component.get(ID_C_identifier);
@@ -3649,11 +3648,10 @@ exprt c_typecheck_baset::do_special_functions(
 
     // The value doesn't matter at all, we only care about the type.
     // Need to sync with typeclass.h.
-    typet type = follow(object.type());
-
     // use underlying type for bit fields
-    if(type.id() == ID_c_bit_field)
-      type = to_c_bit_field_type(type).underlying_type();
+    const typet &type = object.type().id() == ID_c_bit_field
+                          ? to_c_bit_field_type(object.type()).underlying_type()
+                          : object.type();
 
     unsigned type_number;
 
@@ -3665,23 +3663,17 @@ exprt c_typecheck_baset::do_special_functions(
     }
     else
     {
-      type_number =
-        type.id() == ID_empty
-          ? 0u
-          : (type.id() == ID_bool || type.id() == ID_c_bool)
-              ? 4u
-              : (type.id() == ID_pointer || type.id() == ID_array)
-                  ? 5u
-                  : type.id() == ID_floatbv
-                      ? 8u
-                      : (type.id() == ID_complex &&
-                         to_complex_type(type).subtype().id() == ID_floatbv)
-                          ? 9u
-                          : type.id() == ID_struct
-                              ? 12u
-                              : type.id() == ID_union
-                                  ? 13u
-                                  : 1u; // int, short, char, enum_tag
+      type_number = type.id() == ID_empty                                ? 0u
+                    : (type.id() == ID_bool || type.id() == ID_c_bool)   ? 4u
+                    : (type.id() == ID_pointer || type.id() == ID_array) ? 5u
+                    : type.id() == ID_floatbv                            ? 8u
+                    : (type.id() == ID_complex &&
+                       to_complex_type(type).subtype().id() == ID_floatbv)
+                      ? 9u
+                    : type.id() == ID_struct_tag ? 12u
+                    : type.id() == ID_union_tag
+                      ? 13u
+                      : 1u; // int, short, char, enum_tag
     }
 
     exprt tmp=from_integer(type_number, expr.type());