On Fri, Jun 30, 2017 at 01:38:13PM -0400, Nathan Sidwell wrote:
> On 06/30/2017 01:24 PM, Jakub Jelinek wrote:
>
> > The initializer for structured binding has to be one of:
> > = assignment-expression
> > ( assignment-expression )
> > { assignment-expression }
> > but cp_parser_initializer can parse other forms, with fewer or more
> > expressions in there. Some cases we caught with various cryptic errors
> > or pedwarns, but others we just ICEd on.
> >
> > The following patch attempts to check this.
>
> ok, but ...
>
> > --- gcc/testsuite/g++.dg/cpp1z/decomp21.C.jj 2017-01-19
> > 17:01:21.000000000 +0100
> > +++ gcc/testsuite/g++.dg/cpp1z/decomp21.C 2017-06-30 11:07:04.786746784
> > +0200
> > @@ -12,5 +12,5 @@ foo ()
> > auto [ n, o, p ] { a };
> > auto [ q, r, t ] ( s );
> > auto [ u, v, w ] ( s, ); // { dg-error "expected
> > primary-expression before '.' token" }
> > - auto [ x, y, z ] ( a ); // { dg-error "expression list treated as
> > compound expression in initializer" "" { target *-*-* } .-1 }
> > + auto [ x, y, z ] ( a ); // { dg-error "invalid initializer for
> > structured binding" "" { target *-*-* } .-1 }
> > }
>
> The .-1 on the final error is actually about the previous statement, not the
> line it's lexically on. Could you put it on a line on its own, while you're
> there?
Ok. In the light of the http://gcc.gnu.org/ml/gcc-patches/2017-06/msg02432.html
thread, shouldn't this be structured binding declaration then?
I.e.
2017-07-03 Jakub Jelinek <ja...@redhat.com>
PR c++/81258
* parser.c (cp_parser_decomposition_declaration): Diagnose invalid
forms of structured binding initializers.
* g++.dg/cpp1z/decomp21.C (foo): Adjust expected diagnostics.
* g++.dg/cpp1z/decomp30.C: New test.
--- gcc/cp/parser.c.jj 2017-06-30 09:49:25.000000000 +0200
+++ gcc/cp/parser.c 2017-06-30 11:03:18.526521000 +0200
@@ -13196,6 +13196,16 @@ cp_parser_decomposition_declaration (cp_
*init_loc = cp_lexer_peek_token (parser->lexer)->location;
tree initializer = cp_parser_initializer (parser, &is_direct_init,
&non_constant_p);
+ if (initializer == NULL_TREE
+ || (TREE_CODE (initializer) == TREE_LIST
+ && TREE_CHAIN (initializer))
+ || (TREE_CODE (initializer) == CONSTRUCTOR
+ && CONSTRUCTOR_NELTS (initializer) != 1))
+ {
+ error_at (loc, "invalid initializer for structured binding "
+ "declaration");
+ initializer = error_mark_node;
+ }
if (decl != error_mark_node)
{
--- gcc/testsuite/g++.dg/cpp1z/decomp21.C.jj 2017-01-19 17:01:21.000000000
+0100
+++ gcc/testsuite/g++.dg/cpp1z/decomp21.C 2017-06-30 11:07:04.786746784
+0200
@@ -12,5 +12,6 @@ foo ()
auto [ n, o, p ] { a };
auto [ q, r, t ] ( s );
auto [ u, v, w ] ( s, ); // { dg-error "expected primary-expression
before '.' token" }
- auto [ x, y, z ] ( a ); // { dg-error "expression list treated as
compound expression in initializer" "" { target *-*-* } .-1 }
+ // { dg-error "invalid initializer for
structured binding declaration" "" { target *-*-* } .-1 }
+ auto [ x, y, z ] ( a );
}
--- gcc/testsuite/g++.dg/cpp1z/decomp30.C.jj 2017-06-30 11:09:31.934942575
+0200
+++ gcc/testsuite/g++.dg/cpp1z/decomp30.C 2017-06-30 11:09:22.000000000
+0200
@@ -0,0 +1,12 @@
+// PR c++/81258
+// { dg-options -std=c++1z }
+
+int a[2];
+auto [b, c] (a);
+auto [d, e] { a };
+auto [f, g] = a;
+auto [h, i] ( a, a ); // { dg-error "invalid initializer for structured
binding declaration" }
+auto [j, k] { a, a }; // { dg-error "invalid initializer for structured
binding declaration" }
+auto [l, m] = { a }; // { dg-error "deducing from brace-enclosed initializer
list requires" }
+auto [n, o] {}; // { dg-error "invalid initializer for
structured binding declaration" }
+auto [p, q] (); // { dg-error "invalid initializer for
structured binding declaration" }
Jakub
