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| author | Marek Polacek <polacek@redhat.com> | 2020-04-30 11:36:17 -0400 |
|---|---|---|
| committer | Marek Polacek <polacek@redhat.com> | 2020-05-01 16:32:23 -0400 |
| commit | 30da2906ac521749aef8260fc1d942e62073f19d (patch) | |
| tree | ee4e6c68c78be8a57c3ce437992da983e533f6df | |
| parent | 13ec6724cd543fed0211aa60a7f963ad40a2b5b2 (diff) | |
| download | gcc-30da2906ac521749aef8260fc1d942e62073f19d.zip gcc-30da2906ac521749aef8260fc1d942e62073f19d.tar.gz gcc-30da2906ac521749aef8260fc1d942e62073f19d.tar.bz2 | |
c++: Parenthesized-init of aggregates accepts invalid code [PR94885]
Here we have (conceptually *) something like
struct B { };
struct D : B { };
D(0); // invalid
and in C++20 the ()-initialization has created a { 0 } constructor that
it tries to initialize an object of type D with. We should reject
initializing an object of type B from 0, but we wrongly accept it because
process_init_constructor_record skips initializers for empty bases/fields:
if (DECL_SIZE (field) && integer_zerop (DECL_SIZE (field))
&& !TREE_SIDE_EFFECTS (next))
/* Don't add trivial initialization of an empty base/field to the
constructor, as they might not be ordered the way the back-end
expects. */
continue;
but here 'next' was error_mark_node, returned by massage_elt_init, so we
wound up with { } which would validly value-initialize the object.
[*] Usually digest_init in build_new_method_call_1 would detect this,
but in this case the instance is is_dummy_object and we don't call
digest just yet.
PR c++/94885
* typeck2.c (process_init_constructor_record): Return PICFLAG_ERRONEOUS
if an initializer element was erroneous.
* g++.dg/cpp2a/paren-init26.C: New test.
| -rw-r--r-- | gcc/cp/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/cp/typeck2.c | 6 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/cpp2a/paren-init26.C | 14 |
4 files changed, 30 insertions, 1 deletions
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index 0675f98..0b6b0ee 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,9 @@ +2020-05-01 Marek Polacek <polacek@redhat.com> + + PR c++/94885 + * typeck2.c (process_init_constructor_record): Return PICFLAG_ERRONEOUS + if an initializer element was erroneous. + 2020-05-01 Jason Merrill <jason@redhat.com> PR c++/90479 diff --git a/gcc/cp/typeck2.c b/gcc/cp/typeck2.c index 56fd9ba..9e5d145 100644 --- a/gcc/cp/typeck2.c +++ b/gcc/cp/typeck2.c @@ -1661,7 +1661,11 @@ process_init_constructor_record (tree type, tree init, int nested, int flags, ++idx; } } - if (next) + if (next == error_mark_node) + /* We skip initializers for empty bases/fields, so skipping an invalid + one could make us accept invalid code. */ + return PICFLAG_ERRONEOUS; + else if (next) /* Already handled above. */; else if (DECL_INITIAL (field)) { diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 949b81a..997ef8d 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2020-05-01 Marek Polacek <polacek@redhat.com> + + PR c++/94885 + * g++.dg/cpp2a/paren-init26.C: New test. + 2020-05-01 Andreas Tobler <andreast@gcc.gnu.org> * gcc.dg/asan/pr87930.c: Enable on x86_64 FreeBSD. diff --git a/gcc/testsuite/g++.dg/cpp2a/paren-init26.C b/gcc/testsuite/g++.dg/cpp2a/paren-init26.C new file mode 100644 index 0000000..0b98ebf --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/paren-init26.C @@ -0,0 +1,14 @@ +// PR c++/94885 - paren-init of aggregates accepts invalid code. +// { dg-do compile { target c++2a } } + +template <typename T, typename = decltype(T(0))> // { dg-error "could not convert" } +void foo(); + +struct base {}; +struct derived : base {}; + +void +bar() +{ + foo<derived>(); // { dg-error "no matching function" } +} |