MatCat.OpenSource/8sa1-gcc
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

c++: Refine check for CTAD placeholder [PR99586]

Browse Source 
In the below testcase, during finish_compound_literal for A<B{V}>{},
type_uses_auto finds and returns the CTAD placeholder for B{V}, which
tricks us into attempting CTAD on A<B{V}>{} and leads to bogus errors.

AFAICT 'type' will always be a bare 'auto' in the CTAD case so we don't
need to look deeply to find it; checking template_placeholder_p instead
should suffice here.

gcc/cp/ChangeLog:

	PR c++/99586
	* semantics.c (finish_compound_literal): Check
	template_placeholder_p instead of type_uses_auto.

gcc/testsuite/ChangeLog:

	PR c++/99586
	* g++.dg/cpp2a/nontype-class42.C: New test.
This commit is contained in:
Patrick Palka 2021-04-02 19:47:09 -04:00
parent 2a26351b59
commit cf25e27fae
2 changed files with 15 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
gcc/cp/semantics.c
View File

@ -3036,14 +3036,13 @@ finish_compound_literal (tree type, tree compound_literal,
return error_mark_node;
}
if (tree anode = type_uses_auto (type))
if (CLASS_PLACEHOLDER_TEMPLATE (anode))
{
type = do_auto_deduction (type, compound_literal, anode, complain,
adc_variable_type);
if (type == error_mark_node)
return error_mark_node;
}
if (template_placeholder_p (type))
{
type = do_auto_deduction (type, compound_literal, type, complain,
adc_variable_type);
if (type == error_mark_node)
return error_mark_node;
}
/* Used to hold a copy of the compound literal in a template. */
tree orig_cl = NULL_TREE;

8
gcc/testsuite/g++.dg/cpp2a/nontype-class42.C Normal file
View File

@ -0,0 +1,8 @@
// PR c++/99586
// { dg-do compile { target c++20 } }
template <class T>
struct B { constexpr B(T); };
template <auto> struct A{};
template <auto V> auto a = A<B{V}>{};