| Message ID | 20210623233727.2288297-1-ppalka@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | c++: requires-expression folding [PR101182] | expand |
On 6/23/21 7:37 PM, Patrick Palka wrote: > Here we're crashing because cp_fold_function walks into the (templated) > requirements of a requires-expression outside a template, but the > folding routines aren't prepared to handle templated trees. This patch > fixes this by making cp_fold use evaluate_requires_expr to fold a > requires-expression as a whole, which also means we no longer need to > explicitly do so during gimplification. (We don't immediately fold > non-dependent requires-expressions at parse time for sake of better > diagnostics in case one appears as the condition of a failed > static_assert.) > > Bootstrapped and regtested on x86_64-pc-linux-gnu, also tested on > cmcstl2 and range-v3, does this look OK for trunk/11? OK. > PR c++/101182 > > gcc/cp/ChangeLog: > > * constraint.cc (evaluate_requires_expr): Adjust function comment. > * cp-gimplify.c (cp_genericize_r) <case REQUIRES_EXPR>: Move to ... > (cp_fold) <case REQUIRES_EXPR>: ... here. > > gcc/testsuite/ChangeLog: > > * g++.dg/cpp2a/concepts-requires27.C: New test. > --- > gcc/cp/constraint.cc | 2 +- > gcc/cp/cp-gimplify.c | 10 ++++------ > gcc/testsuite/g++.dg/cpp2a/concepts-requires27.C | 10 ++++++++++ > 3 files changed, 15 insertions(+), 7 deletions(-) > create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-requires27.C > > diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc > index 74b16d27101..286332ba2a7 100644 > --- a/gcc/cp/constraint.cc > +++ b/gcc/cp/constraint.cc > @@ -3340,7 +3340,7 @@ evaluate_concept_check (tree check) > } > > /* Evaluate the requires-expression T, returning either boolean_true_node > - or boolean_false_node. This is used during gimplification and constexpr > + or boolean_false_node. This is used during folding and constexpr > evaluation. */ > > tree > diff --git a/gcc/cp/cp-gimplify.c b/gcc/cp/cp-gimplify.c > index 96d91b6ef2f..33e10556e32 100644 > --- a/gcc/cp/cp-gimplify.c > +++ b/gcc/cp/cp-gimplify.c > @@ -1465,12 +1465,6 @@ cp_genericize_r (tree *stmt_p, int *walk_subtrees, void *data) > TARGET_EXPR_NO_ELIDE (stmt) = 1; > break; > > - case REQUIRES_EXPR: > - /* Emit the value of the requires-expression. */ > - *stmt_p = evaluate_requires_expr (stmt); > - *walk_subtrees = 0; > - break; > - > case TEMPLATE_ID_EXPR: > gcc_assert (concept_check_p (stmt)); > /* Emit the value of the concept check. */ > @@ -2708,6 +2702,10 @@ cp_fold (tree x) > x = r; > break; > > + case REQUIRES_EXPR: > + x = evaluate_requires_expr (x); > + break; > + > default: > return org_x; > } > diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-requires27.C b/gcc/testsuite/g++.dg/cpp2a/concepts-requires27.C > new file mode 100644 > index 00000000000..87a759a689a > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-requires27.C > @@ -0,0 +1,10 @@ > +// PR c++/101182 > +// { dg-do compile { target concepts } } > + > +int a; > +int g(bool); > + > +int f() { > + g(requires { a++; }); > + return requires { a++; }; > +} >
diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc index 74b16d27101..286332ba2a7 100644 --- a/gcc/cp/constraint.cc +++ b/gcc/cp/constraint.cc @@ -3340,7 +3340,7 @@ evaluate_concept_check (tree check) } /* Evaluate the requires-expression T, returning either boolean_true_node - or boolean_false_node. This is used during gimplification and constexpr + or boolean_false_node. This is used during folding and constexpr evaluation. */ tree diff --git a/gcc/cp/cp-gimplify.c b/gcc/cp/cp-gimplify.c index 96d91b6ef2f..33e10556e32 100644 --- a/gcc/cp/cp-gimplify.c +++ b/gcc/cp/cp-gimplify.c @@ -1465,12 +1465,6 @@ cp_genericize_r (tree *stmt_p, int *walk_subtrees, void *data) TARGET_EXPR_NO_ELIDE (stmt) = 1; break; - case REQUIRES_EXPR: - /* Emit the value of the requires-expression. */ - *stmt_p = evaluate_requires_expr (stmt); - *walk_subtrees = 0; - break; - case TEMPLATE_ID_EXPR: gcc_assert (concept_check_p (stmt)); /* Emit the value of the concept check. */ @@ -2708,6 +2702,10 @@ cp_fold (tree x) x = r; break; + case REQUIRES_EXPR: + x = evaluate_requires_expr (x); + break; + default: return org_x; } diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-requires27.C b/gcc/testsuite/g++.dg/cpp2a/concepts-requires27.C new file mode 100644 index 00000000000..87a759a689a --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-requires27.C @@ -0,0 +1,10 @@ +// PR c++/101182 +// { dg-do compile { target concepts } } + +int a; +int g(bool); + +int f() { + g(requires { a++; }); + return requires { a++; }; +}