Implement P1152R4: Deprecating some uses of volatile.

	PR c++/91361
	* c-opts.c (c_common_post_options): Enable -Wvolatile by
	default for C++2a, unless -Wno-deprecated.
	* c.opt (Wvolatile): New warning.

	* cp-gimplify.c (cp_fold): Set TREE_THIS_VOLATILE.
	* decl.c (grokdeclarator): Warn about a volatile-qualified structured
	binding and return type.
	(grokparms): Warn about a volatile-qualified function parameter.
	* expr.c (mark_use) <case MODIFY_EXPR>: Emit a -Wvolatile warning.
	* typeck.c (cp_build_unary_op): Emit a -Wvolatile warning for pre and
	post ++/-- on a volatile operand.
	(genericize_compound_lvalue): Use a better location.  Don't lose
	TREE_THIS_VOLATILE.
	(cp_build_modify_expr): Emit a -Wvolatile warning for a compound
	assignment whose LHS is volatile-qualified.  Build the assignment with
	a more precise location.

	* doc/invoke.texi: Document -Wvolatile.

	* c-c++-common/Wbool-operation-1.c: Use -Wno-volatile in C++.
	* c-c++-common/gomp/atomic-1.c: Likewise.
	* c-c++-common/gomp/atomic-9.c: Likewise.
	* c-c++-common/gomp/depend-iterator-1.c: Likewise.
	* c-c++-common/gomp/loop-1.c: Adjust warning location for C++.
	* c-c++-common/gomp/order-3.c: Likewise.
	* c-c++-common/pr69733.c: Use -Wno-volatile in C++.
	* c-c++-common/spec-barrier-2.c: Likewise.
	* c-c++-common/tm/pr54893.c: Likewise.
	* g++.dg/cpp0x/pr65327.C: Add dg-warning.
	* g++.dg/cpp0x/rv-conv2.C: Likewise.
	* g++.dg/cpp0x/rv1n.C: Likewise.
	* g++.dg/cpp0x/rv1p.C: Likewise.
	* g++.dg/cpp0x/rv2n.C: Likewise.
	* g++.dg/cpp0x/rv2p.C: Likewise.
	* g++.dg/cpp0x/rv3n.C: Likewise.
	* g++.dg/cpp0x/rv3p.C: Likewise.
	* g++.dg/cpp0x/rv4n.C: Likewise.
	* g++.dg/cpp0x/rv4p.C: Likewise.
	* g++.dg/cpp0x/rv5n.C: Likewise.
	* g++.dg/cpp0x/rv5p.C: Likewise.
	* g++.dg/cpp0x/rv6n.C: Likewise.
	* g++.dg/cpp0x/rv6p.C: Likewise.
	* g++.dg/cpp0x/rv7n.C: Likewise.
	* g++.dg/cpp0x/rv7p.C: Likewise.
	* g++.dg/cpp0x/rv8p.C: Likewise.
	* g++.dg/cpp0x/trailing14.C: Use -Wno-volatile.
	* g++.dg/cpp1y/new1.C: Add dg-warning.
	* g++.dg/cpp2a/volatile1.C: New test.
	* g++.dg/cpp2a/volatile2.C: New test.
	* g++.dg/cpp2a/volatile3.C: New test.
	* g++.dg/cpp2a/volatile4.C: New test.
	* g++.dg/expr/bool3.C: Add dg-warning.
	* g++.dg/expr/bool4.C: Likewise.
	* g++.dg/expr/cond9.C: Likewise.
	* g++.dg/ext/vector25.C: Likewise.
	* g++.dg/gomp/depend-iterator-1.C: Use -Wno-volatile.
	* g++.dg/inherit/covariant21.C: Add dg-warning.
	* g++.dg/init/ref18.C: Likewise.
	* g++.dg/ipa/pr63838.C: Likewise.
	* g++.dg/overload/rvalue2.C: Likewise.
	* g++.dg/parse/semicolon4.C: Likewise.
	* g++.dg/warn/Wreturn-type-4.C: Likewise.
	* g++.dg/warn/pr36069.C: Likewise.
	* g++.old-deja/g++.mike/p9506.C: Likewise.
	* g++.old-deja/g++.other/volatile1.C: Likewise.

From-SVN: r275022

1 files changed, 18 insertions, 0 deletions

diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index c5cc22a..2aef330 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -11233,6 +11233,10 @@ grokdeclarator (const cp_declarator *declarator,
       if (concept_p)
 	error_at (declspecs->locations[ds_concept],
 		  "structured binding declaration cannot be %qs", "concept");
+      /* [dcl.struct.bind] "A cv that includes volatile is deprecated."  */
+      if (type_quals & TYPE_QUAL_VOLATILE)
+	warning_at (declspecs->locations[ds_volatile], OPT_Wvolatile,
+		    "%<volatile%>-qualified structured binding is deprecated");
       switch (storage_class)
 	{
 	case sc_none:
@@ -11623,6 +11627,13 @@ grokdeclarator (const cp_declarator *declarator,
 		if (SCALAR_TYPE_P (type) || VOID_TYPE_P (type))
 		  warning_at (typespec_loc, OPT_Wignored_qualifiers, "type "
 			      "qualifiers ignored on function return type");
+		/* [dcl.fct] "A volatile-qualified return type is
+		   deprecated."  */
+		if (type_quals & TYPE_QUAL_VOLATILE)
+		  warning_at (typespec_loc, OPT_Wvolatile,
+			      "%<volatile%>-qualified return type is "
+			      "deprecated");
+
 		/* We now know that the TYPE_QUALS don't apply to the
 		   decl, but to its return type.  */
 		type_quals = TYPE_UNQUALIFIED;
@@ -13378,6 +13389,13 @@ grokparms (tree parmlist, tree *parms)
 		cp_warn_deprecated_use (deptype);
 	    }
 
+	  /* [dcl.fct] "A parameter with volatile-qualified type is
+	     deprecated."  */
+	  if (CP_TYPE_VOLATILE_P (type))
+	    warning_at (DECL_SOURCE_LOCATION (decl), OPT_Wvolatile,
+			"%<volatile%>-qualified parameter is "
+			"deprecated");
+
 	  /* Top-level qualifiers on the parameters are
 	     ignored for function types.  */
 	  type = cp_build_qualified_type (type, 0);