| Message ID | Y1bHteXKidcJWWie@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] c++: ICE with invalid structured bindings [PR107276] | expand |
On 10/24/22 13:13, Marek Polacek wrote: > On Mon, Oct 24, 2022 at 10:31:50AM -0400, Jason Merrill wrote: >> On 10/21/22 19:29, Marek Polacek wrote: >>> This test ICEs in C++23 because we reach the new code in do_auto_deduction: >>> >>> 30468 if (cxx_dialect >= cxx23 >>> 30469 && context == adc_return_type >>> 30470 && (!AUTO_IS_DECLTYPE (auto_node) >>> 30471 || !unparenthesized_id_or_class_member_access_p (init)) >>> 30472 && (r = treat_lvalue_as_rvalue_p (maybe_undo_parenthesized_ref (init), >>> 30473 /*return*/true))) >>> >>> where 'init' is "VIEW_CONVERT_EXPR<<<< error >>>>(y)", and then the move >>> in treat_lvalue_as_rvalue_p returns error_mark_node whereupon >>> set_implicit_rvalue_p crashes. >>> >>> I don't think such V_C_Es are useful so let's not create them. But that >>> won't fix the ICE so I'm checking the return value of move. A structured >>> bindings decl can have an error type, that is set in cp_finish_decomp: >>> >>> 8908 TREE_TYPE (first) = error_mark_node; >>> >>> therefore I think treat_lvalue_as_rvalue_p just needs to cope. >>> >>> Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk? >>> >>> PR c++/107276 >>> >>> gcc/cp/ChangeLog: >>> >>> * typeck.cc (treat_lvalue_as_rvalue_p): Check the return value of move. >>> >>> gcc/ChangeLog: >>> >>> * tree.cc (maybe_wrap_with_location): Don't create a location wrapper >>> when the type is erroneous. >>> >>> gcc/testsuite/ChangeLog: >>> >>> * g++.dg/cpp2a/decomp4.C: New test. >>> --- >>> gcc/cp/typeck.cc | 7 ++++++- >>> gcc/testsuite/g++.dg/cpp2a/decomp4.C | 8 ++++++++ >>> gcc/tree.cc | 3 ++- >>> 3 files changed, 16 insertions(+), 2 deletions(-) >>> create mode 100644 gcc/testsuite/g++.dg/cpp2a/decomp4.C >>> >>> diff --git a/gcc/cp/typeck.cc b/gcc/cp/typeck.cc >>> index 16e7d85793d..5ca191759f6 100644 >>> --- a/gcc/cp/typeck.cc >>> +++ b/gcc/cp/typeck.cc >>> @@ -10726,7 +10726,12 @@ treat_lvalue_as_rvalue_p (tree expr, bool return_p) >>> if (DECL_CONTEXT (retval) != current_function_decl) >>> return NULL_TREE; >>> if (return_p) >>> - return set_implicit_rvalue_p (move (expr)); >>> + { >>> + expr = move (expr); >>> + if (expr == error_mark_node) >>> + return NULL_TREE; >>> + return set_implicit_rvalue_p (expr); >>> + } >>> /* if the operand of a throw-expression is a (possibly parenthesized) >>> id-expression that names an implicitly movable entity whose scope does not >>> diff --git a/gcc/testsuite/g++.dg/cpp2a/decomp4.C b/gcc/testsuite/g++.dg/cpp2a/decomp4.C >>> new file mode 100644 >>> index 00000000000..28b3f172b53 >>> --- /dev/null >>> +++ b/gcc/testsuite/g++.dg/cpp2a/decomp4.C >>> @@ -0,0 +1,8 @@ >>> +// PR c++/107276 >>> +// { dg-do run { target c++20 } } >>> + >>> +auto f(auto x) { >>> + auto [y] = x; // { dg-error "cannot decompose" } >>> + return y; >>> +} >>> +int i = f(0); >>> diff --git a/gcc/tree.cc b/gcc/tree.cc >>> index 81a6ceaf181..4e5b1df4d85 100644 >>> --- a/gcc/tree.cc >>> +++ b/gcc/tree.cc >>> @@ -14352,7 +14352,8 @@ maybe_wrap_with_location (tree expr, location_t loc) >>> /* For now, don't add wrappers to exceptional tree nodes, to minimize >>> any impact of the wrapper nodes. */ >>> - if (EXCEPTIONAL_CLASS_P (expr)) >>> + if (EXCEPTIONAL_CLASS_P (expr) >>> + || (TREE_TYPE (expr) && EXCEPTIONAL_CLASS_P (TREE_TYPE (expr)))) >> >> I think check error_operand_p instead; I don't think it makes sense to look >> for other exceptional nodes in TREE_TYPE. > > Makes sense. I don't suppose you want to replace the whole condition with > error_operand_p, only what comes after ||. Updated patch below, thanks. > > Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk? OK. > -- >8 -- > This test ICEs in C++23 because we reach the new code in do_auto_deduction: > > 30468 if (cxx_dialect >= cxx23 > 30469 && context == adc_return_type > 30470 && (!AUTO_IS_DECLTYPE (auto_node) > 30471 || !unparenthesized_id_or_class_member_access_p (init)) > 30472 && (r = treat_lvalue_as_rvalue_p (maybe_undo_parenthesized_ref (init), > 30473 /*return*/true))) > > where 'init' is "VIEW_CONVERT_EXPR<<<< error >>>>(y)", and then the move > in treat_lvalue_as_rvalue_p returns error_mark_node whereupon > set_implicit_rvalue_p crashes. > > I don't think such V_C_Es are useful so let's not create them. But that > won't fix the ICE so I'm checking the return value of move. A structured > bindings decl can have an error type, that is set in cp_finish_decomp: > > 8908 TREE_TYPE (first) = error_mark_node; > > therefore I think treat_lvalue_as_rvalue_p just needs to cope. > > PR c++/107276 > > gcc/cp/ChangeLog: > > * typeck.cc (treat_lvalue_as_rvalue_p): Check the return value of move. > > gcc/ChangeLog: > > * tree.cc (maybe_wrap_with_location): Don't create a location wrapper > when the type is erroneous. > > gcc/testsuite/ChangeLog: > > * g++.dg/cpp2a/decomp4.C: New test. > --- > gcc/cp/typeck.cc | 7 ++++++- > gcc/testsuite/g++.dg/cpp2a/decomp4.C | 8 ++++++++ > gcc/tree.cc | 2 +- > 3 files changed, 15 insertions(+), 2 deletions(-) > create mode 100644 gcc/testsuite/g++.dg/cpp2a/decomp4.C > > diff --git a/gcc/cp/typeck.cc b/gcc/cp/typeck.cc > index 16e7d85793d..5ca191759f6 100644 > --- a/gcc/cp/typeck.cc > +++ b/gcc/cp/typeck.cc > @@ -10726,7 +10726,12 @@ treat_lvalue_as_rvalue_p (tree expr, bool return_p) > if (DECL_CONTEXT (retval) != current_function_decl) > return NULL_TREE; > if (return_p) > - return set_implicit_rvalue_p (move (expr)); > + { > + expr = move (expr); > + if (expr == error_mark_node) > + return NULL_TREE; > + return set_implicit_rvalue_p (expr); > + } > > /* if the operand of a throw-expression is a (possibly parenthesized) > id-expression that names an implicitly movable entity whose scope does not > diff --git a/gcc/testsuite/g++.dg/cpp2a/decomp4.C b/gcc/testsuite/g++.dg/cpp2a/decomp4.C > new file mode 100644 > index 00000000000..d1b0c90ee26 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp2a/decomp4.C > @@ -0,0 +1,8 @@ > +// PR c++/107276 > +// { dg-do compile { target c++20 } } > + > +auto f(auto x) { > + auto [y] = x; // { dg-error "cannot decompose" } > + return y; > +} > +int i = f(0); > diff --git a/gcc/tree.cc b/gcc/tree.cc > index 81a6ceaf181..04603c8c902 100644 > --- a/gcc/tree.cc > +++ b/gcc/tree.cc > @@ -14352,7 +14352,7 @@ maybe_wrap_with_location (tree expr, location_t loc) > > /* For now, don't add wrappers to exceptional tree nodes, to minimize > any impact of the wrapper nodes. */ > - if (EXCEPTIONAL_CLASS_P (expr)) > + if (EXCEPTIONAL_CLASS_P (expr) || error_operand_p (expr)) > return expr; > > /* Compiler-generated temporary variables don't need a wrapper. */ > > base-commit: 131d18e928a3ea1ab2d3bf61aa92d68a8a254609
diff --git a/gcc/cp/typeck.cc b/gcc/cp/typeck.cc index 16e7d85793d..5ca191759f6 100644 --- a/gcc/cp/typeck.cc +++ b/gcc/cp/typeck.cc @@ -10726,7 +10726,12 @@ treat_lvalue_as_rvalue_p (tree expr, bool return_p) if (DECL_CONTEXT (retval) != current_function_decl) return NULL_TREE; if (return_p) - return set_implicit_rvalue_p (move (expr)); + { + expr = move (expr); + if (expr == error_mark_node) + return NULL_TREE; + return set_implicit_rvalue_p (expr); + } /* if the operand of a throw-expression is a (possibly parenthesized) id-expression that names an implicitly movable entity whose scope does not diff --git a/gcc/testsuite/g++.dg/cpp2a/decomp4.C b/gcc/testsuite/g++.dg/cpp2a/decomp4.C new file mode 100644 index 00000000000..d1b0c90ee26 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/decomp4.C @@ -0,0 +1,8 @@ +// PR c++/107276 +// { dg-do compile { target c++20 } } + +auto f(auto x) { + auto [y] = x; // { dg-error "cannot decompose" } + return y; +} +int i = f(0); diff --git a/gcc/tree.cc b/gcc/tree.cc index 81a6ceaf181..04603c8c902 100644 --- a/gcc/tree.cc +++ b/gcc/tree.cc @@ -14352,7 +14352,7 @@ maybe_wrap_with_location (tree expr, location_t loc) /* For now, don't add wrappers to exceptional tree nodes, to minimize any impact of the wrapper nodes. */ - if (EXCEPTIONAL_CLASS_P (expr)) + if (EXCEPTIONAL_CLASS_P (expr) || error_operand_p (expr)) return expr; /* Compiler-generated temporary variables don't need a wrapper. */