[PATCH] c++: Small incremental tweak to source_location::current() folding

[Jakub Jelinek <jakub@redhat.com>]

On Wed, Nov 24, 2021 at 11:42:28PM +0100, Jakub Jelinek via Gcc-patches wrote:
> > I'm surprised the source_location::current handling would be needed; why do
> > calls to that function live long enough for us to walk into the ADDR_EXPR
> > here?  Maybe we should fold it in cp_fold instead of cp_genericize_r.

I've already committed the patch, but perhaps we shouldn't do it in cp_fold
where it will be folded even for warnings etc. and the locations might not
be the final yet.  This patch moves it to cp_fold_r so that it is done just
once for each function and just once for each static initializer.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2021-11-27  Jakub Jelinek  <jakub@redhat.com>

	* cp-gimplify.c (cp_fold_r): Perform folding of
	std::source_location::current() calls here...
	(cp_fold): ... rather than here.

--- gcc/cp/cp-gimplify.c.jj	2021-11-26 10:10:53.227121384 +0100
+++ gcc/cp/cp-gimplify.c	2021-11-26 11:51:50.945204127 +0100
@@ -930,6 +930,13 @@ cp_fold_r (tree *stmt_p, int *walk_subtr
 	}
       break;
 
+    case CALL_EXPR:
+      if (tree fndecl = cp_get_callee_fndecl_nofold (stmt))
+	if (DECL_IMMEDIATE_FUNCTION_P (fndecl)
+	    && source_location_current_p (fndecl))
+	  *stmt_p = stmt = cxx_constant_value (stmt);
+      break;
+
     default:
       break;
     }
@@ -2672,14 +2679,6 @@ cp_fold (tree x)
 	int sv = optimize, nw = sv;
 	tree callee = get_callee_fndecl (x);
 
-	if (tree fndecl = cp_get_callee_fndecl_nofold (x))
-	  if (DECL_IMMEDIATE_FUNCTION_P (fndecl)
-	      && source_location_current_p (fndecl))
-	    {
-	      x = cxx_constant_value (x);
-	      break;
-	    }
-
 	/* Some built-in function calls will be evaluated at compile-time in
 	   fold ().  Set optimize to 1 when folding __builtin_constant_p inside
 	   a constexpr function so that fold_builtin_1 doesn't fold it to 0.  */


	Jakub