constraint.cc
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c++: Some improvements to concept diagnostics · 44f6b7fb
This patch improves our concept diagnostics in two ways. First, it sets a more precise location for the constraint expressions built in finish_constraint_binary_op. As a result, when a disjunction is unsatisfied we now print e.g. .../include/bits/range_access.h:467:2: note: neither operand of the disjunction is satisfied 466 | requires is_bounded_array_v<remove_reference_t<_Tp>> || __member_end<_Tp> | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 467 | || __adl_end<_Tp> | ^~~~~~~~~~~~~~~~~ instead of .../include/bits/range_access.h:467:2: note: neither operand of the disjunction is satisfied 467 | || __adl_end<_Tp> | ^~ Second, this patch changes diagnose_atomic_constraint to print unsatisfied atomic constraint expressions with their template arguments. So e.g. we now print cpp2a/concepts-pr67719.C:9:8: note: the expression ‘(... &&(C<Tx>)()) [with Tx = {int, long int, void}]’ evaluated to ‘false’ instead of cpp2a/concepts-pr67719.C:9:8: note: the expression ‘(... &&(C<Tx>)())’ evaluated to ‘false’ Tested on x86_64-pc-linux-gnu, and verified that all the diagnostics emitted in our concept tests are no worse with this patch. gcc/cp/ChangeLog: * constraint.cc (finish_constraint_binary_op): Set expr's location range to the range of its operands. (satisfy_atom): Pass MAP instead of ARGS to diagnose_atomic_constraint. (diagnose_trait_expr): Take the instantiated parameter mapping MAP instead of the corresponding template arguments ARGS and adjust body accordingly. (diagnose_requires_expr): Likewise. (diagnose_atomic_constraint): Likewise. When printing an atomic constraint expression, print the instantiated parameter mapping alongside it. * cxx-pretty-print.cc (cxx_pretty_printer::expression) [NONTYPE_ARGUMENT_PACK]: Print braces around a NONTYPE_ARGUMENT_PACK. (cxx_pretty_printer::type_id): Handle TYPE_ARGUMENT_PACK. gcc/testsuite/ChangeLog: * g++.dg/concepts/diagnostic2.C: New test. * g++.dg/concepts/diagnostic3.C: New test.
Patrick Palka committed