[Bug c++/100252] [9/10/11/12 Regression] Internal compiler error during template instantiation
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100252 Marek Polacek changed: What|Removed |Added Summary|[9/10/11/12/13 Regression] |[9/10/11/12 Regression] |Internal compiler error |Internal compiler error |during template |during template |instantiation |instantiation --- Comment #12 from Marek Polacek --- Fixed on trunk so far.
[Bug c++/100252] [9/10/11/12 Regression] Internal compiler error during template instantiation
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100252 Marek Polacek changed: What|Removed |Added Status|NEW |ASSIGNED Assignee|unassigned at gcc dot gnu.org |mpolacek at gcc dot gnu.org
[Bug c++/100252] [9/10/11/12 Regression] Internal compiler error during template instantiation
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100252
--- Comment #10 from Marek Polacek ---
Proof of concept:
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -3296,6 +3296,14 @@ finish_compound_literal (tree type, tree
compound_literal,
if (TREE_CODE (compound_literal) == CONSTRUCTOR)
TREE_HAS_CONSTRUCTOR (compound_literal) = false;
compound_literal = get_target_expr_sfinae (compound_literal, complain);
+ if (parsing_nsdmi ())
+ {
+ tree obj = TARGET_EXPR_SLOT (compound_literal);
+ tree = TARGET_EXPR_INITIAL (compound_literal);
+ replace_placeholders (compound_literal, obj);
+ if (TREE_CODE (ctor) == CONSTRUCTOR)
+ CONSTRUCTOR_PLACEHOLDER_BOUNDARY (ctor) = false;
+ }
}
else
/* For e.g. int{42} just make sure it's a prvalue. */
[Bug c++/100252] [9/10/11/12 Regression] Internal compiler error during template instantiation
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100252
--- Comment #9 from Marek Polacek ---
When we are cp_parser_late_parsing_nsdmi for "int y = A{x}.y;" we perform
finish_compound_literal on type=A, compound_literal={((struct B *) this)->x}.
When digesting this initializer, we call get_nsdmi which creates a
PLACEHOLDER_EXPR for A -- we don't have any object to refer to yet. After
digesting, we have
{.x=((struct B *) this)->x, .y=(&)->x}
and since we've created a PLACEHOLDER_EXPR inside it, we marked the whole ctor
CONSTRUCTOR_PLACEHOLDER_BOUNDARY. f_c_l creates a TARGET_EXPR and returns
TARGET_EXPR x, .y=(&)->x}>
(*)
Then we get to
B b = {};
and call store_init_value, which digest the {}, which produces
{.x=NON_LVALUE_EXPR <0>, .y=(TARGET_EXPR )->x, .y=(&)->x}>).y}
The call to replace_placeholders in store_init_value will not do anything:
we've marked the inner { } CONSTRUCTOR_PLACEHOLDER_BOUNDARY, and it's only a
sub-expression, so replace_placeholders does nothing, so the stays even though now it was the perfect time to replace it because
we have an object for it: 'b'.
Later, in cp_gimplify_init_expr the *expr_p is
D.2395 = {.x=(&)->x, .y=(&)->x}
where D.2395 is of type A, but we crash because we hit , which has a different type.
Now here's an idea how we could fix this: at the (*) point in
finish_compound_literal we could replace with
D.2384 because now we have an object! Then clear
CONSTRUCTOR_PLACEHOLDER_BOUNDARY, because we no longer have a PLACEHOLDER_EXPR
in the {}. Then store_init_value will be able to replace with 'b', and we should be good to go.
[Bug c++/100252] [9/10/11/12 Regression] Internal compiler error during template instantiation
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100252
--- Comment #8 from Marek Polacek ---
This is tricky, because we end up with
{.x=(&)->x, .y=(&)->x}
that is, two PLACEHOLDER_EXPRs for different types on the same level in one {
}, so our CONSTRUCTOR_PLACEHOLDER_BOUNDARY mechanism to avoid replacing
unrelated PLACEHOLDER_EXPRs will not work.
[Bug c++/100252] [9/10/11/12 Regression] Internal compiler error during template instantiation
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100252 Richard Biener changed: What|Removed |Added Target Milestone|9.4 |9.5 --- Comment #7 from Richard Biener --- GCC 9.4 is being released, retargeting bugs to GCC 9.5.
[Bug c++/100252] [9/10/11/12 Regression] Internal compiler error during template instantiation
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100252 Jakub Jelinek changed: What|Removed |Added Target Milestone|8.5 |9.4 --- Comment #6 from Jakub Jelinek --- GCC 8 branch is being closed.
