On Tue, Dec 18, 2018 at 05:40:03PM -0500, Jason Merrill wrote:
> On 12/18/18 3:45 PM, Jakub Jelinek wrote:
> > The following testcase FAILs, because parsing creates a TREE_CONSTANT
> > CONSTRUCTOR that contains CONST_DECL elts. cp_fold_r can handle that,
> > but constexpr evaluation doesn't touch those CONSTRUCTORs.
> >
> > Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for
> > trunk?
>
> OK. I also wonder if store_init_value should use cp_fold_r rather than just
> cp_fully_fold.
I've been thinking about that already when working on the PR88410 bug.
Do you mean something like following completely untested patch?
Perhaps I could add a helper inline so that there is no code repetition
between cp_fully_fold and this new function.
Note, it doesn't fix this PR, as store_init_value is called only after we
emit the error, so the constexpr.c patch is needed too.
--- gcc/cp/cp-tree.h.jj 2018-12-12 23:43:57.211129676 +0100
+++ gcc/cp/cp-tree.h 2018-12-19 00:12:59.795154220 +0100
@@ -7542,6 +7542,7 @@ extern bool cxx_omp_privatize_by_referen
extern bool cxx_omp_disregard_value_expr (tree, bool);
extern void cp_fold_function (tree);
extern tree cp_fully_fold (tree);
+extern tree cp_fully_fold_init (tree);
extern void clear_fold_cache (void);
extern tree lookup_hotness_attribute (tree);
extern tree process_stmt_hotness_attribute (tree);
--- gcc/cp/typeck2.c.jj 2018-12-01 00:25:09.340988953 +0100
+++ gcc/cp/typeck2.c 2018-12-19 00:14:19.306875071 +0100
@@ -750,7 +750,7 @@ split_nonconstant_init (tree dest, tree
init = TARGET_EXPR_INITIAL (init);
if (TREE_CODE (init) == CONSTRUCTOR)
{
- init = cp_fully_fold (init);
+ init = cp_fully_fold_init (init);
code = push_stmt_list ();
if (split_nonconstant_init_1 (dest, init))
init = NULL_TREE;
@@ -858,7 +858,7 @@ store_init_value (tree decl, tree init,
if (!const_init)
value = oldval;
}
- value = cp_fully_fold (value);
+ value = cp_fully_fold_init (value);
/* Handle aggregate NSDMI in non-constant initializers, too. */
value = replace_placeholders (value, decl);
--- gcc/cp/cp-gimplify.c.jj 2018-12-17 22:54:02.736416699 +0100
+++ gcc/cp/cp-gimplify.c 2018-12-19 00:12:05.862021875 +0100
@@ -2171,6 +2171,32 @@ cp_fully_fold (tree x)
return cp_fold_rvalue (x);
}
+/* Likewise, but also fold recursively. */
+
+tree
+cp_fully_fold_init (tree x)
+{
+ if (processing_template_decl)
+ return x;
+ /* FIXME cp_fold ought to be a superset of maybe_constant_value so we don't
+ have to call both. */
+ if (cxx_dialect >= cxx11)
+ {
+ x = maybe_constant_value (x);
+ /* Sometimes we are given a CONSTRUCTOR but the call above wraps it into
+ a TARGET_EXPR; undo that here. */
+ if (TREE_CODE (x) == TARGET_EXPR)
+ x = TARGET_EXPR_INITIAL (x);
+ else if (TREE_CODE (x) == VIEW_CONVERT_EXPR
+ && TREE_CODE (TREE_OPERAND (x, 0)) == CONSTRUCTOR
+ && TREE_TYPE (TREE_OPERAND (x, 0)) == TREE_TYPE (x))
+ x = TREE_OPERAND (x, 0);
+ }
+ hash_set<tree> pset;
+ cp_walk_tree (&x, cp_fold_r, &pset, NULL);
+ return cp_fold_rvalue (x);
+}
+
/* c-common interface to cp_fold. If IN_INIT, this is in a static initializer
and certain changes are made to the folding done. Or should be (FIXME). We
never touch maybe_const, as it is only used for the C front-end
Jakub
