From: Nathan Sidwell <nathan@acm.org>
Date: Thu, 3 Dec 2020 20:38:15 +0000 (-0800)
Subject: c++: Exported using decls
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=a3f7a6957a674caf95c4aefa618be51092022e87;p=gcc.git

c++: Exported using decls

With modules we need to record whethe a (namespace-scope) using decl
is exporting the named entities.  Record this on the OVERLOAD marking
the used decl.

	gcc/cp/
	* cp-tree.h (OVL_EXPORT): New.
	(class ovl_iterator): Add get_using, exporting_p.
	* tree.c (ovl_insert): Extend using_or_hidden meaning to include
	an exported using.
---

diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 4db50128443..081ede24e96 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -488,10 +488,9 @@ extern GTY(()) tree cp_global_trees[CPTI_MAX];
       CALL_EXPR_ORDERED_ARGS (in CALL_EXPR, AGGR_INIT_EXPR)
       DECLTYPE_FOR_REF_CAPTURE (in DECLTYPE_TYPE)
       CONSTRUCTOR_C99_COMPOUND_LITERAL (in CONSTRUCTOR)
-      DECL_MODULE_EXPORT_P (in _DECL)
       OVL_NESTED_P (in OVERLOAD)
       LAMBDA_EXPR_INSTANTIATED (in LAMBDA_EXPR)
-      Reserved for DECL_MODULE_EXPORT (in DECL_)
+      DECL_MODULE_EXPORT_P (in _DECL)
    4: IDENTIFIER_MARKED (IDENTIFIER_NODEs)
       TREE_HAS_CONSTRUCTOR (in INDIRECT_REF, SAVE_EXPR, CONSTRUCTOR,
 	  CALL_EXPR, or FIELD_DECL).
@@ -503,6 +502,7 @@ extern GTY(()) tree cp_global_trees[CPTI_MAX];
       FUNCTION_RVALUE_QUALIFIED (in FUNCTION_TYPE, METHOD_TYPE)
       CALL_EXPR_REVERSE_ARGS (in CALL_EXPR, AGGR_INIT_EXPR)
       CONSTRUCTOR_PLACEHOLDER_BOUNDARY (in CONSTRUCTOR)
+      OVL_EXPORT_P (in OVERLOAD)
    6: TYPE_MARKED_P (in _TYPE)
       DECL_NONTRIVIALLY_INITIALIZED_P (in VAR_DECL)
       RANGE_FOR_IVDEP (in RANGE_FOR_STMT)
@@ -780,6 +780,8 @@ typedef struct ptrmem_cst * ptrmem_cst_t;
 #define OVL_NESTED_P(NODE)	TREE_LANG_FLAG_3 (OVERLOAD_CHECK (NODE))
 /* If set, this overload was constructed during lookup.  */
 #define OVL_LOOKUP_P(NODE)	TREE_LANG_FLAG_4 (OVERLOAD_CHECK (NODE))
+/* If set, this OVL_USING_P overload is exported.  */
+#define OVL_EXPORT_P(NODE)	TREE_LANG_FLAG_5 (OVERLOAD_CHECK (NODE))
 
 /* The first decl of an overload.  */
 #define OVL_FIRST(NODE)	ovl_first (NODE)
@@ -839,6 +841,11 @@ class ovl_iterator {
 
     return fn;
   }
+  tree get_using () const
+  {
+    gcc_checking_assert (using_p ());
+    return ovl;
+  }
 
  public:
   /* Whether this overload was introduced by a using decl.  */
@@ -847,6 +854,12 @@ class ovl_iterator {
     return (TREE_CODE (ovl) == USING_DECL
 	    || (TREE_CODE (ovl) == OVERLOAD && OVL_USING_P (ovl)));
   }
+  /* Whether this using is being exported.  */
+  bool exporting_p () const
+  {
+    return OVL_EXPORT_P (get_using ());
+  }
+  
   bool hidden_p () const
   {
     return TREE_CODE (ovl) == OVERLOAD && OVL_HIDDEN_P (ovl);
diff --git a/gcc/cp/tree.c b/gcc/cp/tree.c
index 8d7df60f963..d9fa505041f 100644
--- a/gcc/cp/tree.c
+++ b/gcc/cp/tree.c
@@ -2272,10 +2272,11 @@ ovl_make (tree fn, tree next)
   return result;
 }
 
-/* Add FN to the (potentially NULL) overload set OVL.  USING_OR_HIDDEN
-   is > 0, if FN is via a using declaration.  USING_OR_HIDDEN is < 0,
-   if FN is hidden.  (A decl cannot be both using and hidden.)  We
-   keep the hidden decls first, but remaining ones are unordered.  */
+/* Add FN to the (potentially NULL) overload set OVL.  USING_OR_HIDDEN is >
+   zero if this is a using-decl.  It is > 1 if we're exporting the
+   using decl.  USING_OR_HIDDEN is < 0, if FN is hidden.  (A decl
+   cannot be both using and hidden.)  We keep the hidden decls first,
+   but remaining ones are unordered.  */
 
 tree
 ovl_insert (tree fn, tree maybe_ovl, int using_or_hidden)
@@ -2299,7 +2300,11 @@ ovl_insert (tree fn, tree maybe_ovl, int using_or_hidden)
       if (using_or_hidden < 0)
 	OVL_HIDDEN_P (maybe_ovl) = true;
       if (using_or_hidden > 0)
-	OVL_DEDUP_P (maybe_ovl) = OVL_USING_P (maybe_ovl) = true;
+	{
+	  OVL_DEDUP_P (maybe_ovl) = OVL_USING_P (maybe_ovl) = true;
+	  if (using_or_hidden > 1)
+	    OVL_EXPORT_P (maybe_ovl) = true;
+	}
     }
   else
     maybe_ovl = fn;