| Message ID | 20210401200902.248304-1-ppalka@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series |
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| Related | show |
On 4/1/21 4:09 PM, Patrick Palka wrote: > In the testcase below, during ahead-of-time deduction of a constrained > auto from do_range_for_auto_deduction, we trip over the assert inside > do_auto_deduction that expects the deduction context to be > adc_return_type or adc_variable_type, but the context in this case is > adc_unspecified. > > We could safely relax the assert to also accept adc_unspecified, but it > seems the context should really be adc_variable_type in this case. > > Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for > trunk? OK. > gcc/cp/ChangeLog: > > PR c++/99869 > * parser.c (do_range_for_auto_deduction): Pass adc_variable_type > to do_auto_deduction. > > gcc/testsuite/ChangeLog: > > PR c++/99869 > * g++.dg/cpp2a/concepts-placeholder6.C: New test. > --- > gcc/cp/parser.c | 4 +++- > gcc/testsuite/g++.dg/cpp2a/concepts-placeholder6.C | 10 ++++++++++ > 2 files changed, 13 insertions(+), 1 deletion(-) > create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-placeholder6.C > > diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c > index d0477c42afe..808e5b61b1e 100644 > --- a/gcc/cp/parser.c > +++ b/gcc/cp/parser.c > @@ -12878,7 +12878,9 @@ do_range_for_auto_deduction (tree decl, tree range_expr) > RO_UNARY_STAR, > tf_warning_or_error); > TREE_TYPE (decl) = do_auto_deduction (TREE_TYPE (decl), > - iter_decl, auto_node); > + iter_decl, auto_node, > + tf_warning_or_error, > + adc_variable_type); > } > } > } > diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-placeholder6.C b/gcc/testsuite/g++.dg/cpp2a/concepts-placeholder6.C > new file mode 100644 > index 00000000000..18e7b56d77f > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-placeholder6.C > @@ -0,0 +1,10 @@ > +// PR c++/99869 > +// { dg-do compile { target c++20 } } > + > +template <class T, class U> concept same_as = __is_same(T, U); > + > +template <class> > +void f() { > + for (same_as<int> auto c : "") {} // dg-error "constraint" } > + for (same_as<char> auto c : "") {} > +} >
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c index d0477c42afe..808e5b61b1e 100644 --- a/gcc/cp/parser.c +++ b/gcc/cp/parser.c @@ -12878,7 +12878,9 @@ do_range_for_auto_deduction (tree decl, tree range_expr) RO_UNARY_STAR, tf_warning_or_error); TREE_TYPE (decl) = do_auto_deduction (TREE_TYPE (decl), - iter_decl, auto_node); + iter_decl, auto_node, + tf_warning_or_error, + adc_variable_type); } } } diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-placeholder6.C b/gcc/testsuite/g++.dg/cpp2a/concepts-placeholder6.C new file mode 100644 index 00000000000..18e7b56d77f --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-placeholder6.C @@ -0,0 +1,10 @@ +// PR c++/99869 +// { dg-do compile { target c++20 } } + +template <class T, class U> concept same_as = __is_same(T, U); + +template <class> +void f() { + for (same_as<int> auto c : "") {} // dg-error "constraint" } + for (same_as<char> auto c : "") {} +}