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author | Patrick Palka <ppalka@redhat.com> | 2022-01-11 13:00:48 -0500 |
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committer | Patrick Palka <ppalka@redhat.com> | 2022-01-11 13:00:48 -0500 |
commit | 0378f563b0321c44c4a9c98cf46d2a22b9160f76 (patch) | |
tree | 19cbe16081528335a8b3402da691793765ae4636 /gcc | |
parent | 46de918f9892e637845bd97b4ca95011d46d3733 (diff) | |
download | gcc-0378f563b0321c44c4a9c98cf46d2a22b9160f76.zip gcc-0378f563b0321c44c4a9c98cf46d2a22b9160f76.tar.gz gcc-0378f563b0321c44c4a9c98cf46d2a22b9160f76.tar.bz2 |
c++: dependent bases and 'this' availability [PR103831]
Here during satisfaction of B's constraints we're failing to reject the
object-less call to the non-static member function A::size ultimately
because satisfaction is performed in the (access) context of the class
template B, which has a dependent base, and so the any_dependent_bases_p
check within build_new_method_call causes us to not reject the call.
(Subsequent constexpr evaluation of the call succeeds since the function
is effectively static.)
This patch fixes this by refining the any_dependent_bases_p check within
build_new_method_call: if we're in a context where 'this' is unavailable,
then we cannot resolve the implicit object regardless of the presence of
a dependent base. So let's also check current_class_ptr alongside a_d_b_p.
PR c++/103831
gcc/cp/ChangeLog:
* call.c (build_new_method_call): Consider dependent bases only
if 'this' is available.
gcc/testsuite/ChangeLog:
* g++.dg/cpp2a/concepts-class3.C: New test.
* g++.dg/template/non-dependent18.C: New test.
Diffstat (limited to 'gcc')
-rw-r--r-- | gcc/cp/call.c | 2 | ||||
-rw-r--r-- | gcc/testsuite/g++.dg/cpp2a/concepts-class3.C | 12 | ||||
-rw-r--r-- | gcc/testsuite/g++.dg/template/non-dependent18.C | 19 |
3 files changed, 32 insertions, 1 deletions
diff --git a/gcc/cp/call.c b/gcc/cp/call.c index 88ab233..d4a07a7 100644 --- a/gcc/cp/call.c +++ b/gcc/cp/call.c @@ -11125,7 +11125,7 @@ build_new_method_call (tree instance, tree fns, vec<tree, va_gc> **args, we know we really need it. */ cand->first_arg = instance; } - else if (any_dependent_bases_p ()) + else if (current_class_ptr && any_dependent_bases_p ()) /* We can't tell until instantiation time whether we can use *this as the implicit object argument. */; else diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-class3.C b/gcc/testsuite/g++.dg/cpp2a/concepts-class3.C new file mode 100644 index 0000000..68b50b7 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-class3.C @@ -0,0 +1,12 @@ +// PR c++/103831 +// { dg-do compile { target c++20 } } + +struct A { + constexpr int size() { return 42; } // non-static +}; + +template<class T> + requires (T::size() == 42) // { dg-error "without object" } +struct B : T { }; + +template struct B<A>; // { dg-error "constraint" } diff --git a/gcc/testsuite/g++.dg/template/non-dependent18.C b/gcc/testsuite/g++.dg/template/non-dependent18.C new file mode 100644 index 0000000..3e15568 --- /dev/null +++ b/gcc/testsuite/g++.dg/template/non-dependent18.C @@ -0,0 +1,19 @@ +// PR c++/103831 +// { dg-do compile { target c++11 } } + +struct A { + constexpr int size() { return 42; } // non-static +}; + +template<class T> +struct B : T { + static_assert(A::size() == 42, ""); // { dg-error "without object" } + + static int f() { + static_assert(A::size() == 42, ""); // { dg-error "without object" } + return A::size(); // { dg-error "without object" } + } + + int n = A::size(); + static const int m = A::size(); // { dg-error "without object" } +}; |