[C++ PATCH] Fix pretty-print of enumerator ids (PR c++/87364)

[will wray <wjwray at gmail dot com>]

Hi,

A PR to fix Bug 87364 - Pretty print of enumerator never prints the id,
always falls back to C-style cast output

The fix is tested with the code attached to the bug report and additional
usage over the past few weeks.

Bootstrap and regtested on x86_64-linux. OK for trunk?


2018-10-08  Will Wray  <wjwray@gmail.com>

PR c++/87364
* c-pretty-print.c (pp_c_enumeration_constant): fix comparison.
* cxx-pretty-print.c (pp_cxx_enumeration_constant): New; add
nested-specifiers prefix to enum id plus enum type for scoped enum.

Index: gcc/c-family/c-pretty-print.h
===================================================================
--- gcc/c-family/c-pretty-print.h (revision 264938)
+++ gcc/c-family/c-pretty-print.h (working copy)
@@ -128,11 +128,13 @@ void pp_c_logical_or_expression (c_prett
 void pp_c_expression_list (c_pretty_printer *, tree);
 void pp_c_constructor_elts (c_pretty_printer *, vec<constructor_elt,
va_gc> *);
 void pp_c_call_argument_list (c_pretty_printer *, tree);
+void pp_c_type_cast (c_pretty_printer *, tree);
 void pp_c_cast_expression (c_pretty_printer *, tree);
 void pp_c_init_declarator (c_pretty_printer *, tree);
 void pp_c_ws_string (c_pretty_printer *, const char *);
 void pp_c_identifier (c_pretty_printer *, const char *);
 void pp_c_string_literal (c_pretty_printer *, tree);
+void pp_c_integer_constant (c_pretty_printer *, tree);

 void print_c_tree (FILE *file, tree t);

Index: gcc/c-family/c-pretty-print.c
===================================================================
--- gcc/c-family/c-pretty-print.c (revision 264938)
+++ gcc/c-family/c-pretty-print.c (working copy)
@@ -192,7 +192,7 @@ pp_c_cv_qualifiers (c_pretty_printer *pp

 /* Pretty-print T using the type-cast notation '( type-name )'.  */

-static void
+void
 pp_c_type_cast (c_pretty_printer *pp, tree t)
 {
   pp_c_left_paren (pp);
@@ -908,7 +908,7 @@ pp_c_void_constant (c_pretty_printer *pp

 /* Pretty-print an INTEGER literal.  */

-static void
+void
 pp_c_integer_constant (c_pretty_printer *pp, tree i)
 {
   if (tree_fits_shwi_p (i))
@@ -968,21 +968,20 @@ pp_c_bool_constant (c_pretty_printer *pp
     pp_unsupported_tree (pp, b);
 }

-/* Attempt to print out an ENUMERATOR.  Return true on success.  Else
return
-   false; that means the value was obtained by a cast, in which case
-   print out the type-id part of the cast-expression -- the casted value
-   is then printed by pp_c_integer_literal.  */
+/* Given a value e of ENUMERAL_TYPE:
+   Print out the first ENUMERATOR id with value e, if one is found,
+   else print out the value as a C-style cast (type-id)value.  */

-static bool
+static void
 pp_c_enumeration_constant (c_pretty_printer *pp, tree e)
 {
-  bool value_is_named = true;
   tree type = TREE_TYPE (e);
   tree value;

   /* Find the name of this constant.  */
   for (value = TYPE_VALUES (type);
-       value != NULL_TREE && !tree_int_cst_equal (TREE_VALUE (value), e);
+       value != NULL_TREE
+   && !tree_int_cst_equal (DECL_INITIAL (TREE_VALUE (value)), e);
        value = TREE_CHAIN (value))
     ;

@@ -992,10 +991,8 @@ pp_c_enumeration_constant (c_pretty_prin
     {
       /* Value must have been cast.  */
       pp_c_type_cast (pp, type);
-      value_is_named = false;
+      pp_c_integer_constant (pp, e);
     }
-
-  return value_is_named;
 }

 /* Print out a REAL value as a decimal-floating-constant.  */
@@ -1140,9 +1137,8 @@ c_pretty_printer::constant (tree e)
    pp_c_bool_constant (this, e);
  else if (type == char_type_node)
    pp_c_character_constant (this, e);
- else if (TREE_CODE (type) == ENUMERAL_TYPE
- && pp_c_enumeration_constant (this, e))
-   ;
+ else if (TREE_CODE (type) == ENUMERAL_TYPE)
+   pp_c_enumeration_constant (this, e);
  else
    pp_c_integer_constant (this, e);
       }
Index: gcc/cp/cxx-pretty-print.c
===================================================================
--- gcc/cp/cxx-pretty-print.c (revision 264938)
+++ gcc/cp/cxx-pretty-print.c (working copy)
@@ -294,6 +294,39 @@ pp_cxx_qualified_id (cxx_pretty_printer
     }
 }

+/* Given a value e of ENUMERAL_TYPE:
+   Print out the first ENUMERATOR id with value e, if one is found,
+   (including nested names but excluding the enum name if unscoped)
+   else print out the value as a C-style cast (type-id)value.  */
+
+static void
+pp_cxx_enumeration_constant (cxx_pretty_printer *pp, tree e)
+{
+  tree type = TREE_TYPE (e);
+  tree value;
+
+  /* Find the name of this constant.  */
+  for (value = TYPE_VALUES (type);
+       value != NULL_TREE
+   && !tree_int_cst_equal (DECL_INITIAL (TREE_VALUE (value)), e);
+       value = TREE_CHAIN (value))
+    ;
+
+  if (value != NULL_TREE)
+    {
+      if (!ENUM_IS_SCOPED (type))
+ type = get_containing_scope (type);
+      pp_cxx_nested_name_specifier (pp, type);
+      pp->id_expression (TREE_PURPOSE (value));
+    }
+  else
+    {
+      /* Value must have been cast.  */
+       pp_c_type_cast (pp, type);
+       pp_c_integer_constant (pp, e);
+    }
+}
+

 void
 cxx_pretty_printer::constant (tree t)
@@ -317,6 +350,11 @@ cxx_pretty_printer::constant (tree t)
    pp_string (this, "nullptr");
    break;
  }
+      else if (TREE_CODE (TREE_TYPE (t)) == ENUMERAL_TYPE)
+ {
+   pp_cxx_enumeration_constant (this, t);
+   break;
+ }
       /* fall through.  */

     default: