[gcc(refs/vendors/ARM/heads/morello)] cp: Base __intcap support: parsing, mangling, and diagnostics

[Matthew Malcomson]

https://gcc.gnu.org/g:7fb73dcc84fc3a9fffa03620a4ecc6382d4c6efb

commit 7fb73dcc84fc3a9fffa03620a4ecc6382d4c6efb
Author: Alex Coplan <alex.coplan@arm.com>
Date:   Mon Jan 31 16:50:56 2022 +0000

    cp: Base __intcap support: parsing, mangling, and diagnostics
    
    This adds the base support to the C++ frontend for parsing and mangling
    __intcap types. The changes to the dump_* functions are neded for
    diagnostics involving intcaps.
    
    The mangling follows that used by CHERI LLVM.
    
    gcc/cp/ChangeLog:
    
            * decl.c (grokdeclarator): Handle __intcap.
            * error.c (dump_type): Handle INTCAP_TYPE.
            (dump_type_prefix): Likewise.
            (dump_type_suffix): Likewise.
            * mangle.c (write_type): Likewise.
            (write_builtin_type): Likewise.
            * parser.c (cp_keyword_starts_decl_specifier_p): Likewise.
            (cp_parser_simple_type_specifier): Likewise.

Diff:
---
 gcc/cp/decl.c   | 11 +++++++----
 gcc/cp/error.c  |  3 +++
 gcc/cp/mangle.c | 10 ++++++++++
 gcc/cp/parser.c |  6 ++++++
 4 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index d1af63e7300..fc88567a3cf 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -11552,15 +11552,16 @@ grokdeclarator (const cp_declarator *declarator,
 	  richloc.add_range (declspecs->locations[ds_short]);
 	  error_at (&richloc, "%<long%> and %<short%> specified together");
 	}
-      else if (TREE_CODE (type) != INTEGER_TYPE
+      else if ((TREE_CODE (type) != INTEGER_TYPE && !INTCAP_TYPE_P (type))
 	       || type == char8_type_node
 	       || type == char16_type_node
 	       || type == char32_type_node
 	       || ((long_p || short_p)
-		   && (explicit_char || explicit_intN)))
+		   && (explicit_char || explicit_intN || INTCAP_TYPE_P (type))))
 	error_at (loc, "%qs specified with %qT", key, type);
       else if (!explicit_int && !defaulted_int
-	       && !explicit_char && !explicit_intN)
+	       && !explicit_char && !explicit_intN
+	       && !INTCAP_TYPE_P (type))
 	{
 	  if (typedef_decl)
 	    {
@@ -11608,7 +11609,9 @@ grokdeclarator (const cp_declarator *declarator,
 	  && TREE_CODE (type) == INTEGER_TYPE
 	  && !same_type_p (TYPE_MAIN_VARIANT (type), wchar_type_node)))
     {
-      if (explicit_intN)
+      if (type == intcap_type_node)
+	type = uintcap_type_node;
+      else if (explicit_intN)
 	type = int_n_trees[declspecs->int_n_idx].unsigned_type;
       else if (longlong)
 	type = long_long_unsigned_type_node;
diff --git a/gcc/cp/error.c b/gcc/cp/error.c
index ecb41e82d8c..6c137b30d94 100644
--- a/gcc/cp/error.c
+++ b/gcc/cp/error.c
@@ -527,6 +527,7 @@ dump_type (cxx_pretty_printer *pp, tree t, int flags)
       break;
 
     case INTEGER_TYPE:
+    case INTCAP_TYPE:
     case REAL_TYPE:
     case VOID_TYPE:
     case BOOLEAN_TYPE:
@@ -862,6 +863,7 @@ dump_type_prefix (cxx_pretty_printer *pp, tree t, int flags)
     case ENUMERAL_TYPE:
     case IDENTIFIER_NODE:
     case INTEGER_TYPE:
+    case INTCAP_TYPE:
     case BOOLEAN_TYPE:
     case REAL_TYPE:
     case RECORD_TYPE:
@@ -982,6 +984,7 @@ dump_type_suffix (cxx_pretty_printer *pp, tree t, int flags)
     case ENUMERAL_TYPE:
     case IDENTIFIER_NODE:
     case INTEGER_TYPE:
+    case INTCAP_TYPE:
     case BOOLEAN_TYPE:
     case REAL_TYPE:
     case RECORD_TYPE:
diff --git a/gcc/cp/mangle.c b/gcc/cp/mangle.c
index 9fd30011288..c5fab5057dd 100644
--- a/gcc/cp/mangle.c
+++ b/gcc/cp/mangle.c
@@ -2122,6 +2122,7 @@ write_type (tree type)
 	    case VOID_TYPE:
 	    case BOOLEAN_TYPE:
 	    case INTEGER_TYPE:  /* Includes wchar_t.  */
+	    case INTCAP_TYPE:
 	    case REAL_TYPE:
 	    case FIXED_POINT_TYPE:
 	      {
@@ -2541,6 +2542,15 @@ write_builtin_type (tree type)
 	}
       break;
 
+    case INTCAP_TYPE:
+      {
+	write_char ('u');
+	const char *s = TYPE_UNSIGNED (type) ? "__uintcap_t" : "__intcap_t";
+	write_unsigned_number (strlen (s));
+	write_string (s);
+      }
+      break;
+
     case REAL_TYPE:
       if (type == float_type_node)
 	write_char ('f');
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 7cc2dbed5fe..525a0a27c19 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -1016,6 +1016,7 @@ cp_keyword_starts_decl_specifier_p (enum rid keyword)
     case RID_FLOAT:
     case RID_DOUBLE:
     case RID_VOID:
+    case RID_INTCAP:
       /* GNU extensions.  */
     case RID_ATTRIBUTE:
     case RID_TYPEOF:
@@ -18009,6 +18010,11 @@ cp_parser_simple_type_specifier (cp_parser* parser,
 	}
       type = int_n_trees [idx].signed_type;
       break;
+    case RID_INTCAP:
+      if (!intcap_type_node)
+	break;
+      type = intcap_type_node;
+      break;
     case RID_LONG:
       if (decl_specs)
 	set_and_check_decl_spec_loc (decl_specs, ds_long, token);