Message ID | YfRW5xeo4hE0zZJy@redhat.com |
---|---|
State | New |
Headers | show |
Series | [v2] c++: ICE with auto[] and VLA [PR102414] | expand |
On 1/28/22 15:49, Marek Polacek wrote: > On Thu, Jan 27, 2022 at 10:17:00PM -0500, Jason Merrill wrote: >> On 1/27/22 20:02, Marek Polacek wrote: >>> @@ -11159,8 +11159,16 @@ create_array_type_for_decl (tree name, tree type, tree size, location_t loc) >>> /* Figure out the index type for the array. */ >>> if (size) >>> - itype = compute_array_index_type_loc (loc, name, size, >>> - tf_warning_or_error); >>> + { >>> + itype = compute_array_index_type_loc (loc, name, size, >>> + tf_warning_or_error); >>> + if (type_uses_auto (type) >>> + && !TREE_CONSTANT (maybe_constant_value (size))) >> >> Maybe variably_modified_type_p (itype)? > > Ah yes, I missed that v_m_t_p actually looks at TYPE_MAX_VALUE... > Fixed. > >>> + { >>> + sorry_at (loc, "variable-length array of %<auto%>"); >>> + return error_mark_node; >>> + } >>> + } >>> return build_cplus_array_type (type, itype); >>> } >>> diff --git a/gcc/testsuite/g++.dg/cpp23/auto-array3.C b/gcc/testsuite/g++.dg/cpp23/auto-array3.C >>> new file mode 100644 >>> index 00000000000..e383a17d0ee >>> --- /dev/null >>> +++ b/gcc/testsuite/g++.dg/cpp23/auto-array3.C >>> @@ -0,0 +1,17 @@ >>> +// PR c++/102414 >>> +// { dg-do compile { target c++11 } } >>> +// { dg-options "" } >>> + >>> +constexpr int sz () { return 3; } >>> + >>> +void f () >>> +{ >>> + int a[3]; >>> + auto (*a1)[0/0] = &a; // { dg-message "variable-length array of .auto." } >>> +// { dg-warning "division by zero" "" { target *-*-* } .-1 } >> >> Let's move the error into the other testcase? > > Done. > > Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk? OK. > -- >8 -- > Here we ICE in unify_array_domain when we're trying to deduce the type > of an array, as in > > auto(*p)[i] = (int(*)[i])0; > > but unify_array_domain doesn't arbitrarily complex bounds. Another > test is, e.g., > > auto (*b)[0/0] = &a; > > where the type of the array is > > <<< Unknown tree: template_type_parm >>>[0:(sizetype) ((ssizetype) (0 / 0) - 1)] > > It seems to me that we need not handle these. > > PR c++/102414 > PR c++/101874 > > gcc/cp/ChangeLog: > > * decl.cc (create_array_type_for_decl): Use template_placeholder_p. > Sorry on a variable-length array of auto. > > gcc/testsuite/ChangeLog: > > * g++.dg/cpp23/auto-array3.C: New test. > * g++.dg/cpp23/auto-array4.C: New test. > --- > gcc/cp/decl.cc | 14 +++++++++++--- > gcc/testsuite/g++.dg/cpp23/auto-array3.C | 16 ++++++++++++++++ > gcc/testsuite/g++.dg/cpp23/auto-array4.C | 14 ++++++++++++++ > 3 files changed, 41 insertions(+), 3 deletions(-) > create mode 100644 gcc/testsuite/g++.dg/cpp23/auto-array3.C > create mode 100644 gcc/testsuite/g++.dg/cpp23/auto-array4.C > > diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc > index 26ce9bfefec..09eed9ceba6 100644 > --- a/gcc/cp/decl.cc > +++ b/gcc/cp/decl.cc > @@ -11099,7 +11099,7 @@ create_array_type_for_decl (tree name, tree type, tree size, location_t loc) > > /* [dcl.type.class.deduct] prohibits forming an array of placeholder > for a deduced class type. */ > - if (is_auto (type) && CLASS_PLACEHOLDER_TEMPLATE (type)) > + if (template_placeholder_p (type)) > { > if (name) > error_at (loc, "%qD declared as array of template placeholder " > @@ -11169,8 +11169,16 @@ create_array_type_for_decl (tree name, tree type, tree size, location_t loc) > > /* Figure out the index type for the array. */ > if (size) > - itype = compute_array_index_type_loc (loc, name, size, > - tf_warning_or_error); > + { > + itype = compute_array_index_type_loc (loc, name, size, > + tf_warning_or_error); > + if (type_uses_auto (type) > + && variably_modified_type_p (itype, /*fn=*/NULL_TREE)) > + { > + sorry_at (loc, "variable-length array of %<auto%>"); > + return error_mark_node; > + } > + } > > return build_cplus_array_type (type, itype); > } > diff --git a/gcc/testsuite/g++.dg/cpp23/auto-array3.C b/gcc/testsuite/g++.dg/cpp23/auto-array3.C > new file mode 100644 > index 00000000000..fdf25470fc2 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp23/auto-array3.C > @@ -0,0 +1,16 @@ > +// PR c++/102414 > +// PR c++/101874 > +// { dg-do compile { target c++11 } } > +// { dg-options "" } > + > +constexpr int sz () { return 3; } > + > +void f () > +{ > + int a[3]; > + const int N = 3; > + auto (*a2)[N] = &a; > + constexpr int M = 3; > + auto (*a3)[M] = &a; > + auto (*a4)[sz()] = &a; > +} > diff --git a/gcc/testsuite/g++.dg/cpp23/auto-array4.C b/gcc/testsuite/g++.dg/cpp23/auto-array4.C > new file mode 100644 > index 00000000000..4385c4a6bf9 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp23/auto-array4.C > @@ -0,0 +1,14 @@ > +// PR c++/102414 > +// PR c++/101874 > +// { dg-do compile { target c++11 } } > +// { dg-options "" } > + > +void > +f (int i) > +{ > + auto x[i] = { 0 }; // { dg-message "variable-length array of .auto." } > + auto(*p)[i] = (int(*)[i])0; // { dg-message "variable-length array of .auto." } > + int a[3]; > + auto (*a1)[0/0] = &a; // { dg-message "variable-length array of .auto." } > +// { dg-warning "division by zero" "" { target *-*-* } .-1 } > +} > > base-commit: 3a5fdf986dc6ebb6e244087b462132590ad0a184
diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc index 26ce9bfefec..09eed9ceba6 100644 --- a/gcc/cp/decl.cc +++ b/gcc/cp/decl.cc @@ -11099,7 +11099,7 @@ create_array_type_for_decl (tree name, tree type, tree size, location_t loc) /* [dcl.type.class.deduct] prohibits forming an array of placeholder for a deduced class type. */ - if (is_auto (type) && CLASS_PLACEHOLDER_TEMPLATE (type)) + if (template_placeholder_p (type)) { if (name) error_at (loc, "%qD declared as array of template placeholder " @@ -11169,8 +11169,16 @@ create_array_type_for_decl (tree name, tree type, tree size, location_t loc) /* Figure out the index type for the array. */ if (size) - itype = compute_array_index_type_loc (loc, name, size, - tf_warning_or_error); + { + itype = compute_array_index_type_loc (loc, name, size, + tf_warning_or_error); + if (type_uses_auto (type) + && variably_modified_type_p (itype, /*fn=*/NULL_TREE)) + { + sorry_at (loc, "variable-length array of %<auto%>"); + return error_mark_node; + } + } return build_cplus_array_type (type, itype); } diff --git a/gcc/testsuite/g++.dg/cpp23/auto-array3.C b/gcc/testsuite/g++.dg/cpp23/auto-array3.C new file mode 100644 index 00000000000..fdf25470fc2 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp23/auto-array3.C @@ -0,0 +1,16 @@ +// PR c++/102414 +// PR c++/101874 +// { dg-do compile { target c++11 } } +// { dg-options "" } + +constexpr int sz () { return 3; } + +void f () +{ + int a[3]; + const int N = 3; + auto (*a2)[N] = &a; + constexpr int M = 3; + auto (*a3)[M] = &a; + auto (*a4)[sz()] = &a; +} diff --git a/gcc/testsuite/g++.dg/cpp23/auto-array4.C b/gcc/testsuite/g++.dg/cpp23/auto-array4.C new file mode 100644 index 00000000000..4385c4a6bf9 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp23/auto-array4.C @@ -0,0 +1,14 @@ +// PR c++/102414 +// PR c++/101874 +// { dg-do compile { target c++11 } } +// { dg-options "" } + +void +f (int i) +{ + auto x[i] = { 0 }; // { dg-message "variable-length array of .auto." } + auto(*p)[i] = (int(*)[i])0; // { dg-message "variable-length array of .auto." } + int a[3]; + auto (*a1)[0/0] = &a; // { dg-message "variable-length array of .auto." } +// { dg-warning "division by zero" "" { target *-*-* } .-1 } +}