> On 9 Nov 2021, at 08:07, Iain Sandoe <i...@sandoe.co.uk> wrote:
>
>
>
>> On 9 Nov 2021, at 07:12, Richard Biener <rguent...@suse.de> wrote:
>>
>> On Mon, 8 Nov 2021, Jakub Jelinek wrote:
>>
>>> On Mon, Nov 08, 2021 at 12:46:04PM +0100, Jakub Jelinek via Gcc-patches
>>> wrote:
>>>> So, if we want to make PCH work for PIEs, I'd say we can:
>>>> 1) add a new GTY option, say callback, which would act like
>>>> skip for non-PCH and for PCH would make us skip it but
>>>> remember for address bias translation
>>>> 2) drop the skip for tree_translation_unit_decl::language
>>>> 3) change get_unnamed_section to have const char * as
>>>> last argument instead of const void *, change
>>>> unnamed_section::data also to const char * and update
>>>> everything related to that
>>>> 4) maybe add a host hook whether it is ok to support binaries
>>>> changing addresses (the only thing I'm worried is if
>>>> some host that uses function descriptors allocates them
>>>> dynamically instead of having them somewhere in the
>>>> executable)
>>>> 5) maybe add a gengtype warning if it sees in GTY tracked
>>>> structure a function pointer without that new callback
>>>> option
>>>
>>> So, here is 1), 2), 3) implemented. With this patch alone,
>>> g++.dg/pch/system-2.C test ICEs. This is because GCC 12 has added
>>> function::x_range_query member, which is set to &global_ranges on
>>> cfun creation and is:
>>> range_query * GTY ((skip)) x_range_query;
>>> which means when a PIE binary writes PCH and a PIE binary loaded
>>> at a different address loads it, cfun->x_range_query might be a garbage
>>> pointer. We can either apply a patch like the attached one after
>>> this inline patch, but then probably callback is misnamed and we should
>>> rename it to relocate_and_skip or something similar. Or we could
>>> e.g. during gimplification overwrite cfun->x_range_query = &global_ranges.
>>
>> I think struct function allocation should initialize it to NULL and
>> the init to &global_ranges be done only when we do init_tree_ssa?
>> In fact x_range_query could be moved to the gimple_df substructure
>> to make that clear.
>>
>> Hopefully PCH happens before init_tree_ssa.
>>
>>> Other than that make check-gcc check-g++ passes RUNTESTFLAGS=pch.exp.
>>>
>>> Not really sure about PA or IA-64 function descriptors, are any of those
>>> allocated by the dynamic linker rather than created by the static linker?
>>> I guess instead of removing the c-pch.c changes we could remember there
>>> not just a function pointer, but also a data pointer and compare if both
>>> are either the same or have the same load bias and punt only if they
>>> have different bias. Though, on architecture where all function pointers
>>> would be dynamically allocated and could change any time even that wouldn't
>>> be really a reliable check.
>>>
>>> Note, on stdc++.h.gch/O2g.gch there are just those 10 relocations without
>>> the second patch, with it a few more, but nothing huge. And for non-PIEs
>>> there isn't really any extra work on the load side except freading two
>>> scalar
>>> values and fseek.
>>>
>>> Thoughts on this?
>
> - thanks for doing it, I still think a working solution is better than a
> disable.
>
> - This would be a fix for PR 71934
>
> - I applied the patches on Darwin and there’s still some case(s) to find and
> fix
> cc1/cc1plus hang on pch input, when any diagnostic is emitted (doing some
> linemap lookup) .. hopefully, I can find some time to figure out what is not
> happy.
There were two issues, of which one remains and probably affects all targets.
1. The Darwin PCH memory allocation scheme used a system that works reliably
for no-PIE but not for PIE
.. I hacked in a similar scheme to the mmap one used on Linux .. the suspect
stuff
there is in choosing some place in the map that is likely to succeed…
With that I get passes on all c-family pch.exp (I didn’t try to bootstrap).
2. This problem remains.
- if we try to emit a diagnostic when the PCH read-in has failed, it seems
that
cc1 hangs somewhere in trying to lookup line table info.
- this was happening with the Darwin fixed PCH memory address because it
was trying to report a fatal error in being unable to read the file (or
trying to
execute fancy_abort, in response to a segv).
.. I didn’t try this on Linux - but I would imagine it would be quick to see if
the
problem manifests, one would only need to simulate an error.
Iain
>
>> I'm not keen on further life support for PCH, but then if the work is
>> done it's hard to reject it...
>>
>> Note there might be still platforms not supporting PCH and so Iains
>> patches still look useful to me.
>
> Yeah, what would be most useful at this stage is some way to get those
> tested against some wider set of package builds to see if anything fires
> that breaks stuff.
>
>> I also wonder whether we want to require active marking of types
>> with PCH support and assert when PCH write runs into objects without?
>
> anything that makes GTY markup more robust is a Good Idea.
> Iain
>
>>
>> Richard.
>>
>>> 2021-11-08 Jakub Jelinek <ja...@redhat.com>
>>>
>>> gcc/
>>> * ggc.h (gt_pch_note_callback): Declare.
>>> * gengtype.h (enum typekind): Add TYPE_CALLBACK.
>>> (callback_type): Declare.
>>> * gengtype.c (dbgprint_count_type_at): Handle TYPE_CALLBACK.
>>> (callback_type): New variable.
>>> (process_gc_options): Add CALLBACK argument, handle callback
>>> option.
>>> (set_gc_used_type): Adjust process_gc_options caller, if callback,
>>> set type to &callback_type.
>>> (output_mangled_typename): Handle TYPE_CALLBACK.
>>> (walk_type): Likewise. Handle callback option.
>>> (write_types_process_field): Handle TYPE_CALLBACK.
>>> (write_types_local_user_process_field): Likewise.
>>> (write_types_local_process_field): Likewise.
>>> (write_root): Likewise.
>>> (dump_typekind): Likewise.
>>> (dump_type): Likewise.
>>> * gengtype-state.c (type_lineloc): Handle TYPE_CALLBACK.
>>> (state_writer::write_state_callback_type): New method.
>>> (state_writer::write_state_type): Handle TYPE_CALLBACK.
>>> (read_state_callback_type): New function.
>>> (read_state_type): Handle TYPE_CALLBACK.
>>> * ggc-common.c (callback_vec): New variable.
>>> (gt_pch_note_callback): New function.
>>> (gt_pch_save): Stream out gt_pch_save function address and relocation
>>> table.
>>> (gt_pch_restore): Stream in saved gt_pch_save function address and
>>> relocation table and apply relocations if needed.
>>> * doc/gty.texi (callback): Document new GTY option.
>>> * varasm.c (get_unnamed_section): Change callback argument's type and
>>> last argument's type from const void * to const char *.
>>> (output_section_asm_op): Change argument's type from const void *
>>> to const char *, remove unnecessary cast.
>>> * tree-core.h (struct tree_translation_unit_decl): Drop GTY((skip))
>>> from language member.
>>> * output.h (unnamed_section_callback): Change argument type from
>>> const void * to const char *.
>>> (struct unnamed_section): Use GTY((callback)) instead of GTY((skip))
>>> for callback member. Change data member type from const void *
>>> to const char *.
>>> (struct noswitch_section): Use GTY((callback)) instead of GTY((skip))
>>> for callback member.
>>> (get_unnamed_section): Change callback argument's type and
>>> last argument's type from const void * to const char *.
>>> (output_section_asm_op): Change argument's type from const void *
>>> to const char *.
>>> * config/avr/avr.c (avr_output_progmem_section_asm_op): Likewise.
>>> Remove unneeded cast.
>>> * config/darwin.c (output_objc_section_asm_op): Change argument's type
>>> from const void * to const char *.
>>> * config/pa/pa.c (som_output_text_section_asm_op): Likewise.
>>> (som_output_comdat_data_section_asm_op): Likewise.
>>> * config/rs6000/rs6000.c (rs6000_elf_output_toc_section_asm_op):
>>> Likewise.
>>> (rs6000_xcoff_output_readonly_section_asm_op): Likewise. Instead
>>> of dereferencing directive hardcode variable names and decide based on
>>> whether directive is NULL or not.
>>> (rs6000_xcoff_output_readwrite_section_asm_op): Change argument's type
>>> from const void * to const char *.
>>> (rs6000_xcoff_output_tls_section_asm_op): Likewise. Instead
>>> of dereferencing directive hardcode variable names and decide based on
>>> whether directive is NULL or not.
>>> (rs6000_xcoff_output_toc_section_asm_op): Change argument's type
>>> from const void * to const char *.
>>> (rs6000_xcoff_asm_init_sections): Adjust get_unnamed_section callers.
>>> gcc/c-family/
>>> * c-pch.c (struct c_pch_validity): Remove pch_init member.
>>> (pch_init): Don't initialize v.pch_init.
>>> (c_common_valid_pch): Don't warn and punt if .text addresses change.
>>> libcpp/
>>> * include/line-map.h (class line_maps): Add GTY((callback)) to
>>> reallocator and round_alloc_size members.
>>>
>>> --- gcc/ggc.h.jj 2021-08-19 11:42:27.366422386 +0200
>>> +++ gcc/ggc.h 2021-11-08 16:46:02.604618109 +0100
>>> @@ -46,6 +46,10 @@ typedef void (*gt_handle_reorder) (void
>>> /* Used by the gt_pch_n_* routines. Register an object in the hash table.
>>> */
>>> extern int gt_pch_note_object (void *, void *, gt_note_pointers);
>>>
>>> +/* Used by the gt_pch_p_* routines. Register address of a callback
>>> + pointer. */
>>> +extern void gt_pch_note_callback (void *, void *);
>>> +
>>> /* Used by the gt_pch_n_* routines. Register that an object has a reorder
>>> function. */
>>> extern void gt_pch_note_reorder (void *, void *, gt_handle_reorder);
>>> --- gcc/gengtype.h.jj 2021-07-20 10:08:09.892687719 +0200
>>> +++ gcc/gengtype.h 2021-11-08 15:19:59.194210185 +0100
>>> @@ -154,6 +154,9 @@ enum typekind {
>>> TYPE_UNION, /* Type for GTY-ed discriminated unions. */
>>> TYPE_POINTER, /* Pointer type to GTY-ed type. */
>>> TYPE_ARRAY, /* Array of GTY-ed types. */
>>> + TYPE_CALLBACK, /* A function pointer that needs relocation if
>>> + the executable has been loaded at a different
>>> + address. */
>>> TYPE_LANG_STRUCT, /* GCC front-end language specific structs.
>>> Various languages may have homonymous but
>>> different structs. */
>>> @@ -331,6 +334,9 @@ extern struct type string_type;
>>> extern struct type scalar_nonchar;
>>> extern struct type scalar_char;
>>>
>>> +/* The one and only TYPE_CALLBACK. */
>>> +extern struct type callback_type;
>>> +
>>> /* Test if a type is a union, either a plain one or a language
>>> specific one. */
>>> #define UNION_P(x) \
>>> --- gcc/gengtype.c.jj 2021-10-04 10:16:10.885140187 +0200
>>> +++ gcc/gengtype.c 2021-11-08 16:30:41.981750183 +0100
>>> @@ -172,6 +172,7 @@ dbgprint_count_type_at (const char *fil,
>>> int nb_struct = 0, nb_union = 0, nb_array = 0, nb_pointer = 0;
>>> int nb_lang_struct = 0;
>>> int nb_user_struct = 0, nb_undefined = 0;
>>> + int nb_callback = 0;
>>> type_p p = NULL;
>>> for (p = t; p; p = p->next)
>>> {
>>> @@ -202,6 +203,9 @@ dbgprint_count_type_at (const char *fil,
>>> case TYPE_ARRAY:
>>> nb_array++;
>>> break;
>>> + case TYPE_CALLBACK:
>>> + nb_callback++;
>>> + break;
>>> case TYPE_LANG_STRUCT:
>>> nb_lang_struct++;
>>> break;
>>> @@ -217,6 +221,8 @@ dbgprint_count_type_at (const char *fil,
>>> fprintf (stderr, "@@%%@@ %d structs, %d unions\n", nb_struct, nb_union);
>>> if (nb_pointer > 0 || nb_array > 0)
>>> fprintf (stderr, "@@%%@@ %d pointers, %d arrays\n", nb_pointer,
>>> nb_array);
>>> + if (nb_callback > 0)
>>> + fprintf (stderr, "@@%%@@ %d callbacks\n", nb_callback);
>>> if (nb_lang_struct > 0)
>>> fprintf (stderr, "@@%%@@ %d lang_structs\n", nb_lang_struct);
>>> if (nb_user_struct > 0)
>>> @@ -495,6 +501,10 @@ struct type scalar_char = {
>>> TYPE_SCALAR, 0, 0, 0, GC_USED, {0}
>>> };
>>>
>>> +struct type callback_type = {
>>> + TYPE_CALLBACK, 0, 0, 0, GC_USED, {0}
>>> +};
>>> +
>>> /* Lists of various things. */
>>>
>>> pair_p typedefs = NULL;
>>> @@ -1464,7 +1474,7 @@ static void set_gc_used (pair_p);
>>>
>>> static void
>>> process_gc_options (options_p opt, enum gc_used_enum level, int
>>> *maybe_undef,
>>> - int *length, int *skip, type_p *nested_ptr)
>>> + int *length, int *skip, int *callback, type_p *nested_ptr)
>>> {
>>> options_p o;
>>> for (o = opt; o; o = o->next)
>>> @@ -1478,6 +1488,8 @@ process_gc_options (options_p opt, enum
>>> *length = 1;
>>> else if (strcmp (o->name, "skip") == 0)
>>> *skip = 1;
>>> + else if (strcmp (o->name, "callback") == 0)
>>> + *callback = 1;
>>> else if (strcmp (o->name, "nested_ptr") == 0
>>> && o->kind == OPTION_NESTED)
>>> *nested_ptr = ((const struct nested_ptr_data *) o->info.nested)->type;
>>> @@ -1526,7 +1538,7 @@ set_gc_used_type (type_p t, enum gc_used
>>> type_p dummy2;
>>> bool allow_undefined_field_types = (t->kind == TYPE_USER_STRUCT);
>>>
>>> - process_gc_options (t->u.s.opt, level, &dummy, &dummy, &dummy,
>>> + process_gc_options (t->u.s.opt, level, &dummy, &dummy, &dummy, &dummy,
>>> &dummy2);
>>>
>>> if (t->u.s.base_class)
>>> @@ -1542,9 +1554,10 @@ set_gc_used_type (type_p t, enum gc_used
>>> int maybe_undef = 0;
>>> int length = 0;
>>> int skip = 0;
>>> + int callback = 0;
>>> type_p nested_ptr = NULL;
>>> process_gc_options (f->opt, level, &maybe_undef, &length, &skip,
>>> - &nested_ptr);
>>> + &callback, &nested_ptr);
>>>
>>> if (nested_ptr && f->type->kind == TYPE_POINTER)
>>> set_gc_used_type (nested_ptr, GC_POINTED_TO);
>>> @@ -1554,6 +1567,8 @@ set_gc_used_type (type_p t, enum gc_used
>>> set_gc_used_type (f->type->u.p, GC_MAYBE_POINTED_TO);
>>> else if (skip)
>>> ; /* target type is not used through this field */
>>> + else if (callback)
>>> + f->type = &callback_type;
>>> else
>>> set_gc_used_type (f->type, GC_USED, allow_undefined_field_types);
>>> }
>>> @@ -2519,6 +2534,7 @@ output_mangled_typename (outf_p of, cons
>>> {
>>> case TYPE_NONE:
>>> case TYPE_UNDEFINED:
>>> + case TYPE_CALLBACK:
>>> gcc_unreachable ();
>>> break;
>>> case TYPE_POINTER:
>>> @@ -2719,6 +2735,8 @@ walk_type (type_p t, struct walk_type_da
>>> ;
>>> else if (strcmp (oo->name, "for_user") == 0)
>>> ;
>>> + else if (strcmp (oo->name, "callback") == 0)
>>> + ;
>>> else
>>> error_at_line (d->line, "unknown option `%s'\n", oo->name);
>>>
>>> @@ -2744,6 +2762,7 @@ walk_type (type_p t, struct walk_type_da
>>> {
>>> case TYPE_SCALAR:
>>> case TYPE_STRING:
>>> + case TYPE_CALLBACK:
>>> d->process_field (t, d);
>>> break;
>>>
>>> @@ -3275,6 +3294,7 @@ write_types_process_field (type_p f, con
>>> break;
>>>
>>> case TYPE_SCALAR:
>>> + case TYPE_CALLBACK:
>>> break;
>>>
>>> case TYPE_ARRAY:
>>> @@ -3820,6 +3840,7 @@ write_types_local_user_process_field (ty
>>> break;
>>>
>>> case TYPE_SCALAR:
>>> + case TYPE_CALLBACK:
>>> break;
>>>
>>> case TYPE_ARRAY:
>>> @@ -3906,6 +3927,13 @@ write_types_local_process_field (type_p
>>> case TYPE_SCALAR:
>>> break;
>>>
>>> + case TYPE_CALLBACK:
>>> + oprintf (d->of, "%*sif ((void *)(%s) == this_obj)\n", d->indent, "",
>>> + d->prev_val[3]);
>>> + oprintf (d->of, "%*s gt_pch_note_callback (&(%s), this_obj);\n",
>>> + d->indent, "", d->val);
>>> + break;
>>> +
>>> case TYPE_ARRAY:
>>> case TYPE_NONE:
>>> case TYPE_UNDEFINED:
>>> @@ -4434,6 +4462,7 @@ write_root (outf_p f, pair_p v, type_p t
>>> case TYPE_UNDEFINED:
>>> case TYPE_UNION:
>>> case TYPE_LANG_STRUCT:
>>> + case TYPE_CALLBACK:
>>> error_at_line (line, "global `%s' is unimplemented type", name);
>>> }
>>> }
>>> @@ -4728,6 +4757,9 @@ dump_typekind (int indent, enum typekind
>>> case TYPE_ARRAY:
>>> printf ("TYPE_ARRAY");
>>> break;
>>> + case TYPE_CALLBACK:
>>> + printf ("TYPE_CALLBACK");
>>> + break;
>>> case TYPE_LANG_STRUCT:
>>> printf ("TYPE_LANG_STRUCT");
>>> break;
>>> @@ -4894,6 +4926,7 @@ dump_type (int indent, type_p t)
>>> t->u.scalar_is_char ? "true" : "false");
>>> break;
>>> case TYPE_STRING:
>>> + case TYPE_CALLBACK:
>>> break;
>>> case TYPE_STRUCT:
>>> case TYPE_UNION:
>>> --- gcc/varasm.c.jj 2021-09-28 11:34:29.343147261 +0200
>>> +++ gcc/varasm.c 2021-11-08 13:26:15.032606040 +0100
>>> @@ -250,8 +250,8 @@ object_block_hasher::hash (object_block
>>> /* Return a new unnamed section with the given fields. */
>>>
>>> section *
>>> -get_unnamed_section (unsigned int flags, void (*callback) (const void *),
>>> - const void *data)
>>> +get_unnamed_section (unsigned int flags, void (*callback) (const char *),
>>> + const char *data)
>>> {
>>> section *sect;
>>>
>>> @@ -7778,9 +7778,9 @@ file_end_indicate_split_stack (void)
>>> a get_unnamed_section callback. */
>>>
>>> void
>>> -output_section_asm_op (const void *directive)
>>> +output_section_asm_op (const char *directive)
>>> {
>>> - fprintf (asm_out_file, "%s\n", (const char *) directive);
>>> + fprintf (asm_out_file, "%s\n", directive);
>>> }
>>>
>>> /* Emit assembly code to switch to section NEW_SECTION. Do nothing if
>>> --- gcc/ggc-common.c.jj 2021-11-08 11:09:50.280318624 +0100
>>> +++ gcc/ggc-common.c 2021-11-08 18:33:51.103390391 +0100
>>> @@ -246,6 +246,7 @@ saving_hasher::equal (const ptr_data *p1
>>> }
>>>
>>> static hash_table<saving_hasher> *saving_htab;
>>> +static vec<void *> callback_vec;
>>>
>>> /* Register an object in the hash table. */
>>>
>>> @@ -278,6 +279,23 @@ gt_pch_note_object (void *obj, void *not
>>> return 1;
>>> }
>>>
>>> +/* Register address of a callback pointer. */
>>> +void
>>> +gt_pch_note_callback (void *obj, void *base)
>>> +{
>>> + void *ptr;
>>> + memcpy (&ptr, obj, sizeof (void *));
>>> + if (ptr != NULL)
>>> + {
>>> + struct ptr_data *data
>>> + = (struct ptr_data *)
>>> + saving_htab->find_with_hash (base, POINTER_HASH (base));
>>> + gcc_assert (data);
>>> + callback_vec.safe_push ((char *) data->new_addr
>>> + + ((char *) obj - (char *) base));
>>> + }
>>> +}
>>> +
>>> /* Register an object in the hash table. */
>>>
>>> void
>>> @@ -592,10 +610,20 @@ gt_pch_save (FILE *f)
>>> ggc_pch_finish (state.d, state.f);
>>> gt_pch_fixup_stringpool ();
>>>
>>> + unsigned num_callbacks = callback_vec.length ();
>>> + void (*pch_save) (FILE *) = >_pch_save;
>>> + if (fwrite (&pch_save, sizeof (pch_save), 1, f) != 1
>>> + || fwrite (&num_callbacks, sizeof (num_callbacks), 1, f) != 1
>>> + || (num_callbacks
>>> + && fwrite (callback_vec.address (), sizeof (void *), num_callbacks,
>>> + f) != num_callbacks))
>>> + fatal_error (input_location, "cannot write PCH file: %m");
>>> +
>>> XDELETE (state.ptrs);
>>> XDELETE (this_object);
>>> delete saving_htab;
>>> saving_htab = NULL;
>>> + callback_vec.release ();
>>> }
>>>
>>> /* Read the state of the compiler back in from F. */
>>> @@ -649,6 +677,30 @@ gt_pch_restore (FILE *f)
>>> ggc_pch_read (f, mmi.preferred_base);
>>>
>>> gt_pch_restore_stringpool ();
>>> +
>>> + void (*pch_save) (FILE *);
>>> + unsigned num_callbacks;
>>> + if (fread (&pch_save, sizeof (pch_save), 1, f) != 1
>>> + || fread (&num_callbacks, sizeof (num_callbacks), 1, f) != 1)
>>> + fatal_error (input_location, "cannot read PCH file: %m");
>>> + if (pch_save != >_pch_save)
>>> + {
>>> + uintptr_t bias = (uintptr_t) >_pch_save - (uintptr_t) pch_save;
>>> + void **ptrs = XNEWVEC (void *, num_callbacks);
>>> + unsigned i;
>>> +
>>> + if (fread (ptrs, sizeof (void *), num_callbacks, f) != num_callbacks)
>>> + fatal_error (input_location, "cannot read PCH file: %m");
>>> + for (i = 0; i < num_callbacks; ++i)
>>> + {
>>> + memcpy (&pch_save, ptrs[i], sizeof (pch_save));
>>> + pch_save = (void (*) (FILE *)) ((uintptr_t) pch_save + bias);
>>> + memcpy (ptrs[i], &pch_save, sizeof (pch_save));
>>> + }
>>> + XDELETE (ptrs);
>>> + }
>>> + else if (fseek (f, num_callbacks * sizeof (void *), SEEK_CUR) != 0)
>>> + fatal_error (input_location, "cannot read PCH file: %m");
>>> }
>>>
>>> /* Default version of HOST_HOOKS_GT_PCH_GET_ADDRESS when mmap is not
>>> present.
>>> --- gcc/doc/gty.texi.jj 2021-08-19 11:42:27.363422428 +0200
>>> +++ gcc/doc/gty.texi 2021-11-08 17:13:46.613882767 +0100
>>> @@ -197,6 +197,15 @@ If @code{skip} is applied to a field, th
>>> This is somewhat dangerous; the only safe use is in a union when one
>>> field really isn't ever used.
>>>
>>> +@findex callback
>>> +@item callback
>>> +
>>> +@code{callback} should be applied to fields with pointer to function type
>>> +and causes the field to be ignored similarly to @code{skip}, except when
>>> +writing PCH and the field is non-NULL it will remember the field's address
>>> +for relocation purposes if the process writing PCH has different load base
>>> +from a process reading PCH.
>>> +
>>> @findex for_user
>>> @item for_user
>>>
>>> --- gcc/tree-core.h.jj 2021-11-04 12:27:02.377298411 +0100
>>> +++ gcc/tree-core.h 2021-11-08 13:24:04.496465555 +0100
>>> @@ -1964,7 +1964,7 @@ struct GTY(()) tree_function_decl {
>>> struct GTY(()) tree_translation_unit_decl {
>>> struct tree_decl_common common;
>>> /* Source language of this translation unit. Used for DWARF output. */
>>> - const char * GTY((skip(""))) language;
>>> + const char *language;
>>> /* TODO: Non-optimization used to build this translation unit. */
>>> /* TODO: Root of a partial DWARF tree for global types and decls. */
>>> };
>>> --- gcc/gengtype-state.c.jj 2021-07-20 10:08:09.891687732 +0200
>>> +++ gcc/gengtype-state.c 2021-11-08 15:19:16.157824146 +0100
>>> @@ -57,6 +57,7 @@ type_lineloc (const_type_p ty)
>>> case TYPE_STRING:
>>> case TYPE_POINTER:
>>> case TYPE_ARRAY:
>>> + case TYPE_CALLBACK:
>>> return NULL;
>>> default:
>>> gcc_unreachable ();
>>> @@ -171,6 +172,7 @@ private:
>>> void write_state_version (const char *version);
>>> void write_state_scalar_type (type_p current);
>>> void write_state_string_type (type_p current);
>>> + void write_state_callback_type (type_p current);
>>> void write_state_undefined_type (type_p current);
>>> void write_state_struct_union_type (type_p current, const char *kindstr);
>>> void write_state_struct_type (type_p current);
>>> @@ -898,6 +900,20 @@ state_writer::write_state_string_type (t
>>> fatal ("Unexpected type in write_state_string_type");
>>> }
>>>
>>> +/* Write the callback type. There is only one such thing! */
>>> +void
>>> +state_writer::write_state_callback_type (type_p current)
>>> +{
>>> + if (current == &callback_type)
>>> + {
>>> + write_any_indent (0);
>>> + fprintf (state_file, "callback ");
>>> + write_state_common_type_content (current);
>>> + }
>>> + else
>>> + fatal ("Unexpected type in write_state_callback_type");
>>> +}
>>> +
>>> /* Write an undefined type. */
>>> void
>>> state_writer::write_state_undefined_type (type_p current)
>>> @@ -1143,6 +1159,9 @@ state_writer::write_state_type (type_p c
>>> case TYPE_STRING:
>>> write_state_string_type (current);
>>> break;
>>> + case TYPE_CALLBACK:
>>> + write_state_callback_type (current);
>>> + break;
>>> }
>>> }
>>>
>>> @@ -1477,6 +1496,14 @@ read_state_string_type (type_p *type)
>>> read_state_common_type_content (*type);
>>> }
>>>
>>> +/* Read the callback_type. */
>>> +static void
>>> +read_state_callback_type (type_p *type)
>>> +{
>>> + *type = &callback_type;
>>> + read_state_common_type_content (*type);
>>> +}
>>> +
>>>
>>> /* Read a lang_bitmap representing a set of GCC front-end languages. */
>>> static void
>>> @@ -1834,6 +1861,11 @@ read_state_type (type_p *current)
>>> next_state_tokens (1);
>>> read_state_string_type (current);
>>> }
>>> + else if (state_token_is_name (t0, "callback"))
>>> + {
>>> + next_state_tokens (1);
>>> + read_state_callback_type (current);
>>> + }
>>> else if (state_token_is_name (t0, "undefined"))
>>> {
>>> *current = XCNEW (struct type);
>>> --- gcc/output.h.jj 2021-09-28 11:34:29.235148754 +0200
>>> +++ gcc/output.h 2021-11-08 16:26:01.172755377 +0100
>>> @@ -470,7 +470,7 @@ struct GTY(()) named_section {
>>>
>>> /* A callback that writes the assembly code for switching to an unnamed
>>> section. The argument provides callback-specific data. */
>>> -typedef void (*unnamed_section_callback) (const void *);
>>> +typedef void (*unnamed_section_callback) (const char *);
>>>
>>> /* Information about a SECTION_UNNAMED section. */
>>> struct GTY(()) unnamed_section {
>>> @@ -478,8 +478,8 @@ struct GTY(()) unnamed_section {
>>>
>>> /* The callback used to switch to the section, and the data that
>>> should be passed to the callback. */
>>> - unnamed_section_callback GTY ((skip)) callback;
>>> - const void *GTY ((skip)) data;
>>> + unnamed_section_callback GTY ((callback)) callback;
>>> + const char *data;
>>>
>>> /* The next entry in the chain of unnamed sections. */
>>> section *next;
>>> @@ -503,7 +503,7 @@ struct GTY(()) noswitch_section {
>>> struct section_common common;
>>>
>>> /* The callback used to assemble decls in this section. */
>>> - noswitch_section_callback GTY ((skip)) callback;
>>> + noswitch_section_callback GTY ((callback)) callback;
>>> };
>>>
>>> /* Information about a section, which may be named or unnamed. */
>>> @@ -538,8 +538,8 @@ extern GTY(()) section *bss_noswitch_sec
>>> extern GTY(()) section *in_section;
>>> extern GTY(()) bool in_cold_section_p;
>>>
>>> -extern section *get_unnamed_section (unsigned int, void (*) (const void *),
>>> - const void *);
>>> +extern section *get_unnamed_section (unsigned int, void (*) (const char *),
>>> + const char *);
>>> extern section *get_section (const char *, unsigned int, tree,
>>> bool not_existing = false);
>>> extern section *get_named_section (tree, const char *, int);
>>> @@ -561,7 +561,7 @@ extern section *get_cdtor_priority_secti
>>>
>>> extern bool unlikely_text_section_p (section *);
>>> extern void switch_to_section (section *, tree = nullptr);
>>> -extern void output_section_asm_op (const void *);
>>> +extern void output_section_asm_op (const char *);
>>>
>>> extern void record_tm_clone_pair (tree, tree);
>>> extern void finish_tm_clone_pairs (void);
>>> --- gcc/config/avr/avr.c.jj 2021-07-15 10:16:12.873583249 +0200
>>> +++ gcc/config/avr/avr.c 2021-11-08 13:28:30.215676387 +0100
>>> @@ -10114,10 +10114,9 @@ avr_output_bss_section_asm_op (const voi
>>> /* Unnamed section callback for progmem*.data sections. */
>>>
>>> static void
>>> -avr_output_progmem_section_asm_op (const void *data)
>>> +avr_output_progmem_section_asm_op (const char *data)
>>> {
>>> - fprintf (asm_out_file, "\t.section\t%s,\"a\",@progbits\n",
>>> - (const char*) data);
>>> + fprintf (asm_out_file, "\t.section\t%s,\"a\",@progbits\n", data);
>>> }
>>>
>>>
>>> --- gcc/config/darwin.c.jj 2021-10-21 10:23:27.450834602 +0200
>>> +++ gcc/config/darwin.c 2021-11-08 13:27:19.106691421 +0100
>>> @@ -134,7 +134,7 @@ int emit_aligned_common = false;
>>> DIRECTIVE is as for output_section_asm_op. */
>>>
>>> static void
>>> -output_objc_section_asm_op (const void *directive)
>>> +output_objc_section_asm_op (const char *directive)
>>> {
>>> static bool been_here = false;
>>>
>>> --- gcc/config/pa/pa.c.jj 2021-10-27 09:00:28.762277456 +0200
>>> +++ gcc/config/pa/pa.c 2021-11-08 13:29:41.935652629 +0100
>>> @@ -10011,7 +10011,7 @@ pa_arg_partial_bytes (cumulative_args_t
>>> to the default text subspace. */
>>>
>>> static void
>>> -som_output_text_section_asm_op (const void *data ATTRIBUTE_UNUSED)
>>> +som_output_text_section_asm_op (const char *data ATTRIBUTE_UNUSED)
>>> {
>>> gcc_assert (TARGET_SOM);
>>> if (TARGET_GAS)
>>> @@ -10055,7 +10055,7 @@ som_output_text_section_asm_op (const vo
>>> sections. This function is only used with SOM. */
>>>
>>> static void
>>> -som_output_comdat_data_section_asm_op (const void *data)
>>> +som_output_comdat_data_section_asm_op (const char *data)
>>> {
>>> in_section = NULL;
>>> output_section_asm_op (data);
>>> --- gcc/config/rs6000/rs6000.c.jj 2021-11-05 00:43:22.476626062 +0100
>>> +++ gcc/config/rs6000/rs6000.c 2021-11-08 13:43:22.415940789 +0100
>>> @@ -20597,7 +20597,7 @@ rs6000_ms_bitfield_layout_p (const_tree
>>> /* A get_unnamed_section callback, used for switching to toc_section. */
>>>
>>> static void
>>> -rs6000_elf_output_toc_section_asm_op (const void *data ATTRIBUTE_UNUSED)
>>> +rs6000_elf_output_toc_section_asm_op (const char *data ATTRIBUTE_UNUSED)
>>> {
>>> if ((DEFAULT_ABI == ABI_AIX || DEFAULT_ABI == ABI_ELFv2)
>>> && TARGET_MINIMAL_TOC)
>>> @@ -21301,35 +21301,39 @@ rs6000_xcoff_asm_globalize_label (FILE *
>>> points to the section string variable. */
>>>
>>> static void
>>> -rs6000_xcoff_output_readonly_section_asm_op (const void *directive)
>>> +rs6000_xcoff_output_readonly_section_asm_op (const char *directive)
>>> {
>>> fprintf (asm_out_file, "\t.csect %s[RO],%s\n",
>>> - *(const char *const *) directive,
>>> + directive
>>> + ? xcoff_private_rodata_section_name
>>> + : xcoff_read_only_section_name,
>>> XCOFF_CSECT_DEFAULT_ALIGNMENT_STR);
>>> }
>>>
>>> /* Likewise for read-write sections. */
>>>
>>> static void
>>> -rs6000_xcoff_output_readwrite_section_asm_op (const void *directive)
>>> +rs6000_xcoff_output_readwrite_section_asm_op (const char *)
>>> {
>>> fprintf (asm_out_file, "\t.csect %s[RW],%s\n",
>>> - *(const char *const *) directive,
>>> + xcoff_private_data_section_name,
>>> XCOFF_CSECT_DEFAULT_ALIGNMENT_STR);
>>> }
>>>
>>> static void
>>> -rs6000_xcoff_output_tls_section_asm_op (const void *directive)
>>> +rs6000_xcoff_output_tls_section_asm_op (const char *directive)
>>> {
>>> fprintf (asm_out_file, "\t.csect %s[TL],%s\n",
>>> - *(const char *const *) directive,
>>> + directive
>>> + ? xcoff_private_data_section_name
>>> + : xcoff_tls_data_section_name,
>>> XCOFF_CSECT_DEFAULT_ALIGNMENT_STR);
>>> }
>>>
>>> /* A get_unnamed_section callback, used for switching to toc_section. */
>>>
>>> static void
>>> -rs6000_xcoff_output_toc_section_asm_op (const void *data ATTRIBUTE_UNUSED)
>>> +rs6000_xcoff_output_toc_section_asm_op (const char *data ATTRIBUTE_UNUSED)
>>> {
>>> if (TARGET_MINIMAL_TOC)
>>> {
>>> @@ -21356,26 +21360,26 @@ rs6000_xcoff_asm_init_sections (void)
>>> {
>>> read_only_data_section
>>> = get_unnamed_section (0, rs6000_xcoff_output_readonly_section_asm_op,
>>> - &xcoff_read_only_section_name);
>>> + NULL);
>>>
>>> private_data_section
>>> = get_unnamed_section (SECTION_WRITE,
>>> rs6000_xcoff_output_readwrite_section_asm_op,
>>> - &xcoff_private_data_section_name);
>>> + NULL);
>>>
>>> read_only_private_data_section
>>> = get_unnamed_section (0, rs6000_xcoff_output_readonly_section_asm_op,
>>> - &xcoff_private_rodata_section_name);
>>> + "");
>>>
>>> tls_data_section
>>> = get_unnamed_section (SECTION_TLS,
>>> rs6000_xcoff_output_tls_section_asm_op,
>>> - &xcoff_tls_data_section_name);
>>> + NULL);
>>>
>>> tls_private_data_section
>>> = get_unnamed_section (SECTION_TLS,
>>> rs6000_xcoff_output_tls_section_asm_op,
>>> - &xcoff_private_data_section_name);
>>> + "");
>>>
>>> toc_section
>>> = get_unnamed_section (0, rs6000_xcoff_output_toc_section_asm_op, NULL);
>>> --- gcc/c-family/c-pch.c.jj 2021-06-02 10:08:14.149450407 +0200
>>> +++ gcc/c-family/c-pch.c 2021-11-08 17:34:17.302343697 +0100
>>> @@ -54,7 +54,6 @@ struct c_pch_validity
>>> {
>>> uint32_t pch_write_symbols;
>>> signed char match[MATCH_SIZE];
>>> - void (*pch_init) (void);
>>> size_t target_data_length;
>>> };
>>>
>>> @@ -117,7 +116,6 @@ pch_init (void)
>>> gcc_assert (v.match[i] == *pch_matching[i].flag_var);
>>> }
>>> }
>>> - v.pch_init = &pch_init;
>>> target_validity = targetm.get_pch_validity (&v.target_data_length);
>>>
>>> if (fwrite (partial_pch, IDENT_LENGTH, 1, f) != 1
>>> @@ -278,19 +276,6 @@ c_common_valid_pch (cpp_reader *pfile, c
>>> }
>>> }
>>>
>>> - /* If the text segment was not loaded at the same address as it was
>>> - when the PCH file was created, function pointers loaded from the
>>> - PCH will not be valid. We could in theory remap all the function
>>> - pointers, but no support for that exists at present.
>>> - Since we have the same executable, it should only be necessary to
>>> - check one function. */
>>> - if (v.pch_init != &pch_init)
>>> - {
>>> - cpp_warning (pfile, CPP_W_INVALID_PCH,
>>> - "%s: had text segment at different address", name);
>>> - return 2;
>>> - }
>>> -
>>> /* Check the target-specific validity data. */
>>> {
>>> void *this_file_data = xmalloc (v.target_data_length);
>>> --- libcpp/include/line-map.h.jj 2021-11-01 14:37:06.697853154 +0100
>>> +++ libcpp/include/line-map.h 2021-11-08 16:16:34.562837006 +0100
>>> @@ -803,11 +803,11 @@ public:
>>> unsigned int max_column_hint;
>>>
>>> /* The allocator to use when resizing 'maps', defaults to xrealloc. */
>>> - line_map_realloc reallocator;
>>> + line_map_realloc GTY((callback)) reallocator;
>>>
>>> /* The allocators' function used to know the actual size it
>>> allocated, for a certain allocation size requested. */
>>> - line_map_round_alloc_size_func round_alloc_size;
>>> + line_map_round_alloc_size_func GTY((callback)) round_alloc_size;
>>>
>>> struct location_adhoc_data_map location_adhoc_data_map;
>>>
>>>
>>>
>>> Jakub
>>>
>>
>> --
>> Richard Biener <rguent...@suse.de>
>> SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
>> Germany; GF: Ivo Totev; HRB 36809 (AG Nuernberg)
