Message ID | 20210204084821.GJ4020736@tucnak |
---|---|
State | New |
Headers | show |
Series | c++: Fix ICE with structured binding initialized to incomplete array [PR97878] | expand |
On 2/4/21 3:48 AM, Jakub Jelinek wrote: > Hi! > > We ICE on the following testcase, for incomplete array a on auto [b] { a }; without > giving any kind of diagnostics, with auto [c] = a; during error-recovery. > The problem is that we get too far through check_initializer and e.g. > store_init_value -> constexpr stuff can't deal with incomplete array types. > > As the type of the structured binding artificial variable is always deduced, > I think it is easiest to diagnose this early, even if they have array types > we'll need their deduced type to be complete rather than just its element > type. > > Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? > > 2021-02-04 Jakub Jelinek <jakub@redhat.com> > > PR c++/97878 > * decl.c (check_initializer): For structured bindings, require > complete type even when they have array type. > > * g++.dg/cpp1z/decomp54.C: New test. > > --- gcc/cp/decl.c.jj 2021-01-28 16:13:04.000000000 +0100 > +++ gcc/cp/decl.c 2021-02-03 15:57:16.980557836 +0100 > @@ -6837,7 +6837,8 @@ check_initializer (tree decl, tree init, > /* We will have already complained. */ > return NULL_TREE; > > - if (TREE_CODE (type) == ARRAY_TYPE) > + if (TREE_CODE (type) == ARRAY_TYPE > + && (!DECL_DECOMPOSITION_P (decl) || DECL_DECOMP_BASE (decl))) This needs a comment. Or handle this inside check_array_initializer, where we could give a more helpful diagnostic? > { > if (check_array_initializer (decl, type, init)) > return NULL_TREE; > --- gcc/testsuite/g++.dg/cpp1z/decomp54.C.jj 2021-02-03 16:21:27.991237734 +0100 > +++ gcc/testsuite/g++.dg/cpp1z/decomp54.C 2021-02-03 16:21:10.984428831 +0100 > @@ -0,0 +1,17 @@ > +// PR c++/97878 > +// { dg-do compile { target c++11 } } > +// { dg-options "" } > + > +extern int a[]; > +auto [b] { a }; // { dg-error "has incomplete type" } > + // { dg-warning "only available with" "" { target c++14_down } .-1 } > +auto [c] = a; // { dg-error "has incomplete type" } > + // { dg-warning "only available with" "" { target c++14_down } .-1 } > +extern int d[0]; > +auto [e] { d }; // { dg-error "too many initializers for" } > + // { dg-error "1 name provided for structured binding" "" { target *-*-* } .-1 } > + // { dg-message "decomposes into 0 elements" "" { target *-*-* } .-2 } > + // { dg-warning "only available with" "" { target c++14_down } .-3 } > +auto [f] = d; // { dg-error "1 name provided for structured binding" } > + // { dg-message "decomposes into 0 elements" "" { target *-*-* } .-1 } > + // { dg-warning "only available with" "" { target c++14_down } .-2 } > > Jakub >
On Thu, Feb 04, 2021 at 11:03:10AM -0500, Jason Merrill wrote: > > --- gcc/cp/decl.c.jj 2021-01-28 16:13:04.000000000 +0100 > > +++ gcc/cp/decl.c 2021-02-03 15:57:16.980557836 +0100 > > @@ -6837,7 +6837,8 @@ check_initializer (tree decl, tree init, > > /* We will have already complained. */ > > return NULL_TREE; > > - if (TREE_CODE (type) == ARRAY_TYPE) > > + if (TREE_CODE (type) == ARRAY_TYPE > > + && (!DECL_DECOMPOSITION_P (decl) || DECL_DECOMP_BASE (decl))) > > This needs a comment. Or handle this inside check_array_initializer, where > we could give a more helpful diagnostic? So like this? 2021-02-04 Jakub Jelinek <jakub@redhat.com> PR c++/97878 * decl.c (check_array_initializer): For structured bindings, require the array type to be complete. * g++.dg/cpp1z/decomp54.C: New test. --- gcc/cp/decl.c.jj 2021-02-03 17:13:58.567872007 +0100 +++ gcc/cp/decl.c 2021-02-04 18:42:35.347374198 +0100 @@ -6768,6 +6768,19 @@ check_array_initializer (tree decl, tree { tree element_type = TREE_TYPE (type); + /* Structured binding when initialized with an array type needs + to have complete type. */ + if (decl + && DECL_DECOMPOSITION_P (decl) + && !DECL_DECOMP_BASE (decl) + && !COMPLETE_TYPE_P (type)) + { + error_at (DECL_SOURCE_LOCATION (decl), + "structured binding has incomplete type"); + TREE_TYPE (decl) = error_mark_node; + return true; + } + /* The array type itself need not be complete, because the initializer may tell us how many elements are in the array. But, the elements of the array must be complete. */ --- gcc/testsuite/g++.dg/cpp1z/decomp54.C.jj 2021-02-04 18:33:34.829393825 +0100 +++ gcc/testsuite/g++.dg/cpp1z/decomp54.C 2021-02-04 18:33:34.829393825 +0100 @@ -0,0 +1,17 @@ +// PR c++/97878 +// { dg-do compile { target c++11 } } +// { dg-options "" } + +extern int a[]; +auto [b] { a }; // { dg-error "has incomplete type" } + // { dg-warning "only available with" "" { target c++14_down } .-1 } +auto [c] = a; // { dg-error "has incomplete type" } + // { dg-warning "only available with" "" { target c++14_down } .-1 } +extern int d[0]; +auto [e] { d }; // { dg-error "too many initializers for" } + // { dg-error "1 name provided for structured binding" "" { target *-*-* } .-1 } + // { dg-message "decomposes into 0 elements" "" { target *-*-* } .-2 } + // { dg-warning "only available with" "" { target c++14_down } .-3 } +auto [f] = d; // { dg-error "1 name provided for structured binding" } + // { dg-message "decomposes into 0 elements" "" { target *-*-* } .-1 } + // { dg-warning "only available with" "" { target c++14_down } .-2 } Jakub
On 2/4/21 12:47 PM, Jakub Jelinek wrote: > On Thu, Feb 04, 2021 at 11:03:10AM -0500, Jason Merrill wrote: >>> --- gcc/cp/decl.c.jj 2021-01-28 16:13:04.000000000 +0100 >>> +++ gcc/cp/decl.c 2021-02-03 15:57:16.980557836 +0100 >>> @@ -6837,7 +6837,8 @@ check_initializer (tree decl, tree init, >>> /* We will have already complained. */ >>> return NULL_TREE; >>> - if (TREE_CODE (type) == ARRAY_TYPE) >>> + if (TREE_CODE (type) == ARRAY_TYPE >>> + && (!DECL_DECOMPOSITION_P (decl) || DECL_DECOMP_BASE (decl))) >> >> This needs a comment. Or handle this inside check_array_initializer, where >> we could give a more helpful diagnostic? > > So like this? > > 2021-02-04 Jakub Jelinek <jakub@redhat.com> > > PR c++/97878 > * decl.c (check_array_initializer): For structured bindings, require > the array type to be complete. > > * g++.dg/cpp1z/decomp54.C: New test. > > --- gcc/cp/decl.c.jj 2021-02-03 17:13:58.567872007 +0100 > +++ gcc/cp/decl.c 2021-02-04 18:42:35.347374198 +0100 > @@ -6768,6 +6768,19 @@ check_array_initializer (tree decl, tree > { > tree element_type = TREE_TYPE (type); > > + /* Structured binding when initialized with an array type needs > + to have complete type. */ > + if (decl > + && DECL_DECOMPOSITION_P (decl) > + && !DECL_DECOMP_BASE (decl) > + && !COMPLETE_TYPE_P (type)) > + { > + error_at (DECL_SOURCE_LOCATION (decl), > + "structured binding has incomplete type"); Let's print the type. OK with that change. > + TREE_TYPE (decl) = error_mark_node; > + return true; > + } > + > /* The array type itself need not be complete, because the > initializer may tell us how many elements are in the array. > But, the elements of the array must be complete. */ > --- gcc/testsuite/g++.dg/cpp1z/decomp54.C.jj 2021-02-04 18:33:34.829393825 +0100 > +++ gcc/testsuite/g++.dg/cpp1z/decomp54.C 2021-02-04 18:33:34.829393825 +0100 > @@ -0,0 +1,17 @@ > +// PR c++/97878 > +// { dg-do compile { target c++11 } } > +// { dg-options "" } > + > +extern int a[]; > +auto [b] { a }; // { dg-error "has incomplete type" } > + // { dg-warning "only available with" "" { target c++14_down } .-1 } > +auto [c] = a; // { dg-error "has incomplete type" } > + // { dg-warning "only available with" "" { target c++14_down } .-1 } > +extern int d[0]; > +auto [e] { d }; // { dg-error "too many initializers for" } > + // { dg-error "1 name provided for structured binding" "" { target *-*-* } .-1 } > + // { dg-message "decomposes into 0 elements" "" { target *-*-* } .-2 } > + // { dg-warning "only available with" "" { target c++14_down } .-3 } > +auto [f] = d; // { dg-error "1 name provided for structured binding" } > + // { dg-message "decomposes into 0 elements" "" { target *-*-* } .-1 } > + // { dg-warning "only available with" "" { target c++14_down } .-2 } > > > Jakub >
--- gcc/cp/decl.c.jj 2021-01-28 16:13:04.000000000 +0100 +++ gcc/cp/decl.c 2021-02-03 15:57:16.980557836 +0100 @@ -6837,7 +6837,8 @@ check_initializer (tree decl, tree init, /* We will have already complained. */ return NULL_TREE; - if (TREE_CODE (type) == ARRAY_TYPE) + if (TREE_CODE (type) == ARRAY_TYPE + && (!DECL_DECOMPOSITION_P (decl) || DECL_DECOMP_BASE (decl))) { if (check_array_initializer (decl, type, init)) return NULL_TREE; --- gcc/testsuite/g++.dg/cpp1z/decomp54.C.jj 2021-02-03 16:21:27.991237734 +0100 +++ gcc/testsuite/g++.dg/cpp1z/decomp54.C 2021-02-03 16:21:10.984428831 +0100 @@ -0,0 +1,17 @@ +// PR c++/97878 +// { dg-do compile { target c++11 } } +// { dg-options "" } + +extern int a[]; +auto [b] { a }; // { dg-error "has incomplete type" } + // { dg-warning "only available with" "" { target c++14_down } .-1 } +auto [c] = a; // { dg-error "has incomplete type" } + // { dg-warning "only available with" "" { target c++14_down } .-1 } +extern int d[0]; +auto [e] { d }; // { dg-error "too many initializers for" } + // { dg-error "1 name provided for structured binding" "" { target *-*-* } .-1 } + // { dg-message "decomposes into 0 elements" "" { target *-*-* } .-2 } + // { dg-warning "only available with" "" { target c++14_down } .-3 } +auto [f] = d; // { dg-error "1 name provided for structured binding" } + // { dg-message "decomposes into 0 elements" "" { target *-*-* } .-1 } + // { dg-warning "only available with" "" { target c++14_down } .-2 }