On Sun, 14 Apr 2024, Martin Uecker wrote: > > I had to revert the old patch because it broke LTO which lead > to PR114574. We now set TYPE_STRUCTURAL_EQUALITY and properly > update TYPE_CANONICAL for such types and also for pointers > to such types via a new function c_update_type_canonical > (thanks to Jakob). > > > Bootstrapped and regession tested on x86_64. > > > > Fix ICE with -g and -std=c23 related to incomplete types [PR114361] > > We did not update TYPE_CANONICAL for incomplete variants when > completing a structure. We now set TYPE_STRUCTURAL_EQUALITY for > incomplete structure and union types and then update TYPE_CANONICAL > later. See PR114574 for discussion. > > > 2024-04-12 Martin Uecker <uec...@tugraz.at> > Jakub Jelinek <ja...@redhat.com> > > PR lto/114574 > PR c/114361 > gcc/ > * ipa-free-lang-data.cc (fld_incomplete_type_of): Allow > either of the types in the assert to have TYPE_STRUCTURAL_EQUALITY_P. > gcc/c/ > * c-decl.cc (shadow_tag_warned): For flag_isoc23 and code not > ENUMERAL_TYPE use SET_TYPE_STRUCTURAL_EQUALITY. > (parser_xref_tag): Likewise. > (start_struct): For flag_isoc23 use SET_TYPE_STRUCTURAL_EQUALITY. > (c_update_type_canonical): New function. > (finish_struct): Put NULL as second == operand rather than first. > Assert TYPE_STRUCTURAL_EQUALITY_P. Call c_update_type_canonical. > * c-typeck.cc (composite_type_internal): Use > SET_TYPE_STRUCTURAL_EQUALITY. Formatting fix. > gcc/testsuite/ > * gcc.dg/pr114574-1.c: New test. > * gcc.dg/pr114574-2.c: New test. > * gcc.dg/pr114361.c: New test. > * gcc.dg/c23-tag-incomplete-1.c: New test. > * gcc.dg/c23-tag-incomplete-2.c: New test. > --- > gcc/c/c-decl.cc | 47 ++++++++++++++++++++- > gcc/c/c-typeck.cc | 4 +- > gcc/ipa-free-lang-data.cc | 4 +- > gcc/testsuite/gcc.dg/c23-tag-incomplete-1.c | 14 ++++++ > gcc/testsuite/gcc.dg/c23-tag-incomplete-2.c | 13 ++++++ > gcc/testsuite/gcc.dg/pr114361.c | 11 +++++ > gcc/testsuite/gcc.dg/pr114574-1.c | 10 +++++ > gcc/testsuite/gcc.dg/pr114574-2.c | 10 +++++ > 8 files changed, 110 insertions(+), 3 deletions(-) > create mode 100644 gcc/testsuite/gcc.dg/c23-tag-incomplete-1.c > create mode 100644 gcc/testsuite/gcc.dg/c23-tag-incomplete-2.c > create mode 100644 gcc/testsuite/gcc.dg/pr114361.c > create mode 100644 gcc/testsuite/gcc.dg/pr114574-1.c > create mode 100644 gcc/testsuite/gcc.dg/pr114574-2.c > > diff --git a/gcc/c/c-decl.cc b/gcc/c/c-decl.cc > index 345090dae38..54917297b6a 100644 > --- a/gcc/c/c-decl.cc > +++ b/gcc/c/c-decl.cc > @@ -5051,6 +5051,8 @@ shadow_tag_warned (const struct c_declspecs *declspecs, > int warned) > if (t == NULL_TREE) > { > t = make_node (code); > + if (flag_isoc23 && code != ENUMERAL_TYPE) > + SET_TYPE_STRUCTURAL_EQUALITY (t); > pushtag (input_location, name, t); > } > } > @@ -8809,6 +8811,8 @@ parser_xref_tag (location_t loc, enum tree_code code, > tree name, > the forward-reference will be altered into a real type. */ > > ref = make_node (code); > + if (flag_isoc23 && code != ENUMERAL_TYPE) > + SET_TYPE_STRUCTURAL_EQUALITY (ref); > if (code == ENUMERAL_TYPE) > { > /* Give the type a default layout like unsigned int > @@ -8910,6 +8914,8 @@ start_struct (location_t loc, enum tree_code code, tree > name, > if (ref == NULL_TREE || TREE_CODE (ref) != code) > { > ref = make_node (code); > + if (flag_isoc23) > + SET_TYPE_STRUCTURAL_EQUALITY (ref); > pushtag (loc, name, ref); > } > > @@ -9347,6 +9353,43 @@ is_flexible_array_member_p (bool is_last_field, > return false; > } > > +/* Recompute TYPE_CANONICAL for qualified versions of the type and > + related pointer types after an aggregate type has been finalized. > + Will not update array types, pointers to array types, function > + types and other derived types created while the type was still > + incomplete, those will remain TYPE_STRUCTURAL_EQUALITY_P. */ > + > +static void > +c_update_type_canonical (tree t) > +{ > + for (tree x = TYPE_MAIN_VARIANT (t); x; x = TYPE_NEXT_VARIANT (x)) > + { > + if (x != t > + && TYPE_STRUCTURAL_EQUALITY_P (x) > + && check_qualified_type (x, t, TYPE_QUALS (x))) > + { > + if (TYPE_CANONICAL (t) != t) > + TYPE_CANONICAL (x) > + = build_qualified_type (TYPE_CANONICAL (t), TYPE_QUALS (x)); > + else > + TYPE_CANONICAL (x) = x; > + } > + else if (x != t) > + continue; > + for (tree p = TYPE_POINTER_TO (x); p; p = TYPE_NEXT_PTR_TO (p)) > + { > + if (!TYPE_STRUCTURAL_EQUALITY_P (p)) > + continue; > + if (TYPE_CANONICAL (x) != x || TYPE_REF_CAN_ALIAS_ALL (p)) > + TYPE_CANONICAL (p) > + = build_pointer_type_for_mode (TYPE_CANONICAL (x), TYPE_MODE (p), > + false); > + else > + TYPE_CANONICAL (p) = p; > + c_update_type_canonical (p); > + } > + } > +} > > /* Fill in the fields of a RECORD_TYPE or UNION_TYPE node, T. > LOC is the location of the RECORD_TYPE or UNION_TYPE's definition. > @@ -9695,11 +9738,12 @@ finish_struct (location_t loc, tree t, tree > fieldlist, tree attributes, > /* Set type canonical based on equivalence class. */ > if (flag_isoc23) > { > - if (NULL == c_struct_htab) > + if (c_struct_htab == NULL) > c_struct_htab = hash_table<c_struct_hasher>::create_ggc (61); > > hashval_t hash = c_struct_hasher::hash (t); > > + gcc_checking_assert (TYPE_STRUCTURAL_EQUALITY_P (t)); > tree *e = c_struct_htab->find_slot_with_hash (t, hash, INSERT); > if (*e) > TYPE_CANONICAL (t) = *e; > @@ -9708,6 +9752,7 @@ finish_struct (location_t loc, tree t, tree fieldlist, > tree attributes, > TYPE_CANONICAL (t) = t; > *e = t; > } > + c_update_type_canonical (t); > } > > tree incomplete_vars = C_TYPE_INCOMPLETE_VARS (TYPE_MAIN_VARIANT (t)); > diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc > index ddeab1e2a8a..4567b114734 100644 > --- a/gcc/c/c-typeck.cc > +++ b/gcc/c/c-typeck.cc > @@ -532,6 +532,7 @@ composite_type_internal (tree t1, tree t2, struct > composite_cache* cache) > /* Otherwise, create a new type node and link it into the cache. */ > > tree n = make_node (code1); > + SET_TYPE_STRUCTURAL_EQUALITY (n); > TYPE_NAME (n) = TYPE_NAME (t1); > > struct composite_cache cache2 = { t1, t2, n, cache }; > @@ -590,7 +591,8 @@ composite_type_internal (tree t1, tree t2, struct > composite_cache* cache) > TYPE_STUB_DECL (n) = pushdecl (build_decl (input_location, TYPE_DECL, > NULL_TREE, n)); > > - n = finish_struct(input_location, n, fields, attributes, NULL, &expr); > + n = finish_struct (input_location, n, fields, attributes, NULL, > + &expr); > > n = qualify_type (n, t1); > > diff --git a/gcc/ipa-free-lang-data.cc b/gcc/ipa-free-lang-data.cc > index 16ed55e2e5a..6f75444e513 100644 > --- a/gcc/ipa-free-lang-data.cc > +++ b/gcc/ipa-free-lang-data.cc > @@ -255,7 +255,9 @@ fld_incomplete_type_of (tree t, class free_lang_data_d > *fld) > first = build_reference_type_for_mode (t2, TYPE_MODE (t), > TYPE_REF_CAN_ALIAS_ALL (t)); > gcc_assert (TYPE_CANONICAL (t2) != t2 > - && TYPE_CANONICAL (t2) == TYPE_CANONICAL (TREE_TYPE (t))); > + && (TYPE_CANONICAL (t2) == TYPE_CANONICAL (TREE_TYPE (t)) > + || TYPE_STRUCTURAL_EQUALITY_P (t2) > + || TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (t))));
I think we want the same canonical types for t2 and TREE_TYPE (t), why doesn't fld_incomplete_type_of make it so? Richard. > if (!fld->pset.add (first)) > add_tree_to_fld_list (first, fld); > return fld_type_variant (first, t, fld); > diff --git a/gcc/testsuite/gcc.dg/c23-tag-incomplete-1.c > b/gcc/testsuite/gcc.dg/c23-tag-incomplete-1.c > new file mode 100644 > index 00000000000..82d652569e9 > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/c23-tag-incomplete-1.c > @@ -0,0 +1,14 @@ > +/* { dg-do compile } > + * { dg-options "-std=c23 -g" } */ > + > +struct a; > +typedef struct a b; > + > +void g() { > + struct a { b* x; }; > +} > + > +struct a { b* x; }; > + > + > + > diff --git a/gcc/testsuite/gcc.dg/c23-tag-incomplete-2.c > b/gcc/testsuite/gcc.dg/c23-tag-incomplete-2.c > new file mode 100644 > index 00000000000..bc47a04ece5 > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/c23-tag-incomplete-2.c > @@ -0,0 +1,13 @@ > +/* { dg-do compile } > + * { dg-options "-std=c23 -g" } */ > + > +struct a; > +typedef struct a b; > + > +void f() { > + extern struct a { b* x; } t; > +} > + > +extern struct a { b* x; } t; > + > + > diff --git a/gcc/testsuite/gcc.dg/pr114361.c b/gcc/testsuite/gcc.dg/pr114361.c > new file mode 100644 > index 00000000000..0f3feb53566 > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/pr114361.c > @@ -0,0 +1,11 @@ > +/* PR c/114361 */ > +/* { dg-do compile } */ > +/* { dg-options "-std=gnu23 -g" } */ > + > +void f() > +{ > + typedef struct foo bar; > + typedef __typeof( ({ (struct foo { bar *x; }){ }; }) ) wuz; > + struct foo { wuz *x; }; > +} > + > diff --git a/gcc/testsuite/gcc.dg/pr114574-1.c > b/gcc/testsuite/gcc.dg/pr114574-1.c > new file mode 100644 > index 00000000000..060dcdbe73e > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/pr114574-1.c > @@ -0,0 +1,10 @@ > +/* PR lto/114574 > + * { dg-do compile } > + * { dg-options "-flto" } */ > + > +const struct S * x; > +struct S {}; > +void f(const struct S **); > + > + > + > diff --git a/gcc/testsuite/gcc.dg/pr114574-2.c > b/gcc/testsuite/gcc.dg/pr114574-2.c > new file mode 100644 > index 00000000000..723291e2211 > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/pr114574-2.c > @@ -0,0 +1,10 @@ > +/* PR lto/114574 > + * { dg-do compile } > + * { dg-options "-flto -std=c23" } */ > + > +const struct S * x; > +struct S {}; > +void f(const struct S **); > + > + > + > -- Richard Biener <rguent...@suse.de> SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg, Germany; GF: Ivo Totev, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)