[PATCH PR/82546] tree node size

[Nathan Sidwell <nathan@acm.org>]

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[Although I filed this as a middle-end bug, it's really a core infra 
bug, not sure who the best reviewer is]

In working on tree streaming in the modules branch, I discovered poor 
tree node size and hierarchy bits.

Here's a fix for the first part of that.  tree.c (tree_code_size) 
returns sizeof (tree_type_non_common) for any tcc_type node. That's 
wasteful, given we have tree_type_common-> 
tree_type_with_lang_specific-> tree_type_non_common available as 
choices.  It's also obscuring defects in (at least) the c++ FE where we 
use tree_type_non_common fields, but claim the node doesn't contain that 
structure.   Ew.

This patch makes tree_code_size ask the lang hook for the size of 
non-core type nodes.  It also fixes the c++ and objc FEs to return a 
size for the nodes it cares about.

I don't (yet) know whether all the core types are tree_type_non_common, 
nor whether the FE's can return smaller sizes than the do with this 
patch.  But at least the control flow is now correct.  during developing 
this patch I added an assert that the lang hook was returning a size at 
least as big as tree_type_non_common, so they couldn't be more broken 
than before the patch.

I intend to continue cleaning this up of course.  It's not clear to me 
whether we should cache these node sizes in an array, and the way it 
goes about checking nodes with nested switches is understandable, but 
possible not the fastest solution. However let's at least get the sizing 
right first.

ok?

nathan
-- 
Nathan Sidwell

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2017-10-13  Nathan Sidwell  <nathan@acm.org>

	PR middle-end/82546
	gcc/
	* tree.c (tree_code_size): Reformat.  Punt to lang hook for unknown
	TYPE nodes.
	gcc/cp/
	* cp-objcp-common.c (cp_tree_size): Reformat.  Adjust returns size
	of TYPE nodes.
	gcc/objc/
	* objc-act.c (objc_common_tree_size): Return size of TYPE nodes.

Index: cp/cp-objcp-common.c
===================================================================
--- cp/cp-objcp-common.c	(revision 253733)
+++ cp/cp-objcp-common.c	(working copy)
@@ -61,43 +61,34 @@ cxx_warn_unused_global_decl (const_tree
 size_t
 cp_tree_size (enum tree_code code)
 {
+  gcc_checking_assert (code >= NUM_TREE_CODES);
   switch (code)
     {
-    case PTRMEM_CST:		return sizeof (struct ptrmem_cst);
-    case BASELINK:		return sizeof (struct tree_baselink);
+    case PTRMEM_CST:		return sizeof (ptrmem_cst);
+    case BASELINK:		return sizeof (tree_baselink);
     case TEMPLATE_PARM_INDEX:	return sizeof (template_parm_index);
-    case DEFAULT_ARG:		return sizeof (struct tree_default_arg);
-    case DEFERRED_NOEXCEPT:	return sizeof (struct tree_deferred_noexcept);
-    case OVERLOAD:		return sizeof (struct tree_overload);
-    case STATIC_ASSERT:         return sizeof (struct tree_static_assert);
+    case DEFAULT_ARG:		return sizeof (tree_default_arg);
+    case DEFERRED_NOEXCEPT:	return sizeof (tree_deferred_noexcept);
+    case OVERLOAD:		return sizeof (tree_overload);
+    case STATIC_ASSERT:         return sizeof (tree_static_assert);
     case TYPE_ARGUMENT_PACK:
-    case TYPE_PACK_EXPANSION:
-      return sizeof (struct tree_common);
-
+    case TYPE_PACK_EXPANSION:	return sizeof (tree_type_non_common);
     case NONTYPE_ARGUMENT_PACK:
-    case EXPR_PACK_EXPANSION:
-      return sizeof (struct tree_exp);
-
-    case ARGUMENT_PACK_SELECT:
-      return sizeof (struct tree_argument_pack_select);
-
-    case TRAIT_EXPR:
-      return sizeof (struct tree_trait_expr);
-
-    case LAMBDA_EXPR:           return sizeof (struct tree_lambda_expr);
-
-    case TEMPLATE_INFO:         return sizeof (struct tree_template_info);
-
-    case CONSTRAINT_INFO:       return sizeof (struct tree_constraint_info);
-
-    case USERDEF_LITERAL:	return sizeof (struct tree_userdef_literal);
-
-    case TEMPLATE_DECL:		return sizeof (struct tree_template_decl);
-
+    case EXPR_PACK_EXPANSION:	return sizeof (tree_exp);
+    case ARGUMENT_PACK_SELECT:	return sizeof (tree_argument_pack_select);
+    case TRAIT_EXPR:		return sizeof (tree_trait_expr);
+    case LAMBDA_EXPR:           return sizeof (tree_lambda_expr);
+    case TEMPLATE_INFO:         return sizeof (tree_template_info);
+    case CONSTRAINT_INFO:       return sizeof (tree_constraint_info);
+    case USERDEF_LITERAL:	return sizeof (tree_userdef_literal);
+    case TEMPLATE_DECL:		return sizeof (tree_template_decl);
     default:
-      if (TREE_CODE_CLASS (code) == tcc_declaration)
-	return sizeof (struct tree_decl_non_common);
-      gcc_unreachable ();
+      switch (TREE_CODE_CLASS (code))
+	{
+	case tcc_declaration:	return sizeof (tree_decl_non_common);
+	case tcc_type:		return sizeof (tree_type_non_common);
+	default: gcc_unreachable ();
+	}
     }
   /* NOTREACHED */
 }
Index: objc/objc-act.c
===================================================================
--- objc/objc-act.c	(revision 253733)
+++ objc/objc-act.c	(working copy)
@@ -10118,11 +10118,14 @@ objc_common_tree_size (enum tree_code co
     case CLASS_METHOD_DECL:
     case INSTANCE_METHOD_DECL:
     case KEYWORD_DECL:
-    case PROPERTY_DECL:
-      return sizeof (struct tree_decl_non_common);
+    case PROPERTY_DECL:			return sizeof (tree_decl_non_common);
+    case CLASS_INTERFACE_TYPE:
+    case CLASS_IMPLEMENTATION_TYPE:
+    case CATEGORY_INTERFACE_TYPE:
+    case CATEGORY_IMPLEMENTATION_TYPE:
+    case PROTOCOL_INTERFACE_TYPE:	return sizeof (tree_type_non_common);
     default:
       gcc_unreachable ();
-  
     }
 }
 
Index: tree.c
===================================================================
--- tree.c	(revision 253733)
+++ tree.c	(working copy)
@@ -763,40 +763,53 @@ tree_code_size (enum tree_code code)
   switch (TREE_CODE_CLASS (code))
     {
     case tcc_declaration:  /* A decl node */
-      {
-	switch (code)
-	  {
-	  case FIELD_DECL:
-	    return sizeof (struct tree_field_decl);
-	  case PARM_DECL:
-	    return sizeof (struct tree_parm_decl);
-	  case VAR_DECL:
-	    return sizeof (struct tree_var_decl);
-	  case LABEL_DECL:
-	    return sizeof (struct tree_label_decl);
-	  case RESULT_DECL:
-	    return sizeof (struct tree_result_decl);
-	  case CONST_DECL:
-	    return sizeof (struct tree_const_decl);
-	  case TYPE_DECL:
-	    return sizeof (struct tree_type_decl);
-	  case FUNCTION_DECL:
-	    return sizeof (struct tree_function_decl);
-	  case DEBUG_EXPR_DECL:
-	    return sizeof (struct tree_decl_with_rtl);
-	  case TRANSLATION_UNIT_DECL:
-	    return sizeof (struct tree_translation_unit_decl);
-	  case NAMESPACE_DECL:
-	  case IMPORTED_DECL:
-	  case NAMELIST_DECL:
-	    return sizeof (struct tree_decl_non_common);
-	  default:
-	    return lang_hooks.tree_size (code);
-	  }
-      }
+      switch (code)
+	{
+	case FIELD_DECL:	return sizeof (tree_field_decl);
+	case PARM_DECL:		return sizeof (tree_parm_decl);
+	case VAR_DECL:		return sizeof (tree_var_decl);
+	case LABEL_DECL:	return sizeof (tree_label_decl);
+	case RESULT_DECL:	return sizeof (tree_result_decl);
+	case CONST_DECL:	return sizeof (tree_const_decl);
+	case TYPE_DECL:		return sizeof (tree_type_decl);
+	case FUNCTION_DECL:	return sizeof (tree_function_decl);
+	case DEBUG_EXPR_DECL:	return sizeof (tree_decl_with_rtl);
+	case TRANSLATION_UNIT_DECL: return sizeof (tree_translation_unit_decl);
+	case NAMESPACE_DECL:
+	case IMPORTED_DECL:
+	case NAMELIST_DECL:	return sizeof (tree_decl_non_common);
+	default:
+	  gcc_checking_assert (code >= NUM_TREE_CODES);
+	  return lang_hooks.tree_size (code);
+	}
 
     case tcc_type:  /* a type node */
-      return sizeof (struct tree_type_non_common);
+      switch (code)
+	{
+	case OFFSET_TYPE:
+	case ENUMERAL_TYPE:
+	case BOOLEAN_TYPE:
+	case INTEGER_TYPE:
+	case REAL_TYPE:
+	case POINTER_TYPE:
+	case REFERENCE_TYPE:
+	case NULLPTR_TYPE:
+	case FIXED_POINT_TYPE:
+	case COMPLEX_TYPE:
+	case VECTOR_TYPE:
+	case ARRAY_TYPE:
+	case RECORD_TYPE:
+	case UNION_TYPE:
+	case QUAL_UNION_TYPE:
+	case VOID_TYPE:
+	case POINTER_BOUNDS_TYPE:
+	case FUNCTION_TYPE:
+	case METHOD_TYPE:
+	case LANG_TYPE:		return sizeof (tree_type_non_common);
+	default:
+	  gcc_checking_assert (code >= NUM_TREE_CODES);
+	  return lang_hooks.tree_size (code);
+	}
 
     case tcc_reference:   /* a reference */
     case tcc_expression:  /* an expression */
@@ -810,14 +823,15 @@ tree_code_size (enum tree_code code)
     case tcc_constant:  /* a constant */
       switch (code)
 	{
-	case VOID_CST:		return sizeof (struct tree_typed);
+	case VOID_CST:		return sizeof (tree_typed);
 	case INTEGER_CST:	gcc_unreachable ();
-	case REAL_CST:		return sizeof (struct tree_real_cst);
-	case FIXED_CST:		return sizeof (struct tree_fixed_cst);
-	case COMPLEX_CST:	return sizeof (struct tree_complex);
-	case VECTOR_CST:	return sizeof (struct tree_vector);
+	case REAL_CST:		return sizeof (tree_real_cst);
+	case FIXED_CST:		return sizeof (tree_fixed_cst);
+	case COMPLEX_CST:	return sizeof (tree_complex);
+	case VECTOR_CST:	return sizeof (tree_vector);
 	case STRING_CST:	gcc_unreachable ();
 	default:
+	  gcc_checking_assert (code >= NUM_TREE_CODES);
 	  return lang_hooks.tree_size (code);
 	}
 
@@ -825,23 +839,24 @@ tree_code_size (enum tree_code code)
       switch (code)
 	{
 	case IDENTIFIER_NODE:	return lang_hooks.identifier_size;
-	case TREE_LIST:		return sizeof (struct tree_list);
+	case TREE_LIST:		return sizeof (tree_list);
 
 	case ERROR_MARK:
-	case PLACEHOLDER_EXPR:	return sizeof (struct tree_common);
+	case PLACEHOLDER_EXPR:	return sizeof (tree_common);
 
-	case TREE_VEC:
+	case TREE_VEC:		gcc_unreachable ();
 	case OMP_CLAUSE:	gcc_unreachable ();
 
-	case SSA_NAME:		return sizeof (struct tree_ssa_name);
+	case SSA_NAME:		return sizeof (tree_ssa_name);
 
-	case STATEMENT_LIST:	return sizeof (struct tree_statement_list);
+	case STATEMENT_LIST:	return sizeof (tree_statement_list);
 	case BLOCK:		return sizeof (struct tree_block);
-	case CONSTRUCTOR:	return sizeof (struct tree_constructor);
-	case OPTIMIZATION_NODE: return sizeof (struct tree_optimization_option);
-	case TARGET_OPTION_NODE: return sizeof (struct tree_target_option);
+	case CONSTRUCTOR:	return sizeof (tree_constructor);
+	case OPTIMIZATION_NODE: return sizeof (tree_optimization_option);
+	case TARGET_OPTION_NODE: return sizeof (tree_target_option);
 
 	default:
+	  gcc_checking_assert (code >= NUM_TREE_CODES);
 	  return lang_hooks.tree_size (code);
 	}