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| author | David Malcolm <dmalcolm@redhat.com> | 2013-10-29 01:16:05 +0000 |
|---|---|---|
| committer | David Malcolm <dmalcolm@gcc.gnu.org> | 2013-10-29 01:16:05 +0000 |
| commit | 32fe52714e42a391c6a7a1ac18bb0a57a80ecb5b (patch) | |
| tree | 456914960b33f804e0e0a01a2caaa7e312150c73 | |
| parent | 1ed5a6cc504ef8089f1431590c2fbca15b6a2475 (diff) | |
| download | gcc-32fe52714e42a391c6a7a1ac18bb0a57a80ecb5b.zip gcc-32fe52714e42a391c6a7a1ac18bb0a57a80ecb5b.tar.gz gcc-32fe52714e42a391c6a7a1ac18bb0a57a80ecb5b.tar.bz2 | |
Make gengtype more robust against user error
* doc/gty.texi ("Inheritance and GTY"): Make it clear that
to use autogenerated markers for a class-hierarchy, every class
must have a GTY marker.
* gengtype.h (struct type): Add linked list of subclasses to
the "s" member of the union.
(add_subclass): New decl.
* gengtype-state.c (read_state_struct_type): Set up subclass
linked list.
* gengtype.c (get_ultimate_base_class): New.
(add_subclass): New.
(new_structure): Set up subclass linked list.
(set_gc_used_type): Propagate usage information to subclasses.
(output_mangled_typename): Use get_ultimate_base_class.
(walk_subclasses): Use the subclass linked list, avoiding an
O(N^2) when writing out all types.
(walk_type): Issue an error if the base class is missing a tag,
rather than generating bogus C code. Add a gcc_unreachable
default case, in case people omit tags from concrete subclasses,
or get the values wrong.
(write_func_for_structure): Issue an error for subclasses for
which the base doesn't have a "desc", since otherwise the
autogenerated routines for the base would silently fail to visit
any subclass fields.
(write_root): Use get_ultimate_base_class, tweaking constness of
tp to match that function's signature.
From-SVN: r204148
| -rw-r--r-- | gcc/ChangeLog | 28 | ||||
| -rw-r--r-- | gcc/doc/gty.texi | 7 | ||||
| -rw-r--r-- | gcc/gengtype-state.c | 2 | ||||
| -rw-r--r-- | gcc/gengtype.c | 119 | ||||
| -rw-r--r-- | gcc/gengtype.h | 10 |
5 files changed, 137 insertions, 29 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index ac7c86b..fca665b 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,33 @@ 2013-10-29 David Malcolm <dmalcolm@redhat.com> + * doc/gty.texi ("Inheritance and GTY"): Make it clear that + to use autogenerated markers for a class-hierarchy, every class + must have a GTY marker. + * gengtype.h (struct type): Add linked list of subclasses to + the "s" member of the union. + (add_subclass): New decl. + * gengtype-state.c (read_state_struct_type): Set up subclass + linked list. + * gengtype.c (get_ultimate_base_class): New. + (add_subclass): New. + (new_structure): Set up subclass linked list. + (set_gc_used_type): Propagate usage information to subclasses. + (output_mangled_typename): Use get_ultimate_base_class. + (walk_subclasses): Use the subclass linked list, avoiding an + O(N^2) when writing out all types. + (walk_type): Issue an error if the base class is missing a tag, + rather than generating bogus C code. Add a gcc_unreachable + default case, in case people omit tags from concrete subclasses, + or get the values wrong. + (write_func_for_structure): Issue an error for subclasses for + which the base doesn't have a "desc", since otherwise the + autogenerated routines for the base would silently fail to visit + any subclass fields. + (write_root): Use get_ultimate_base_class, tweaking constness of + tp to match that function's signature. + +2013-10-29 David Malcolm <dmalcolm@redhat.com> + * doc/gty.texi (GTY Options): Add note about inheritance to description of desc and tag. (Inheritance and GTY): New. diff --git a/gcc/doc/gty.texi b/gcc/doc/gty.texi index 090f6a6..a64d110 100644 --- a/gcc/doc/gty.texi +++ b/gcc/doc/gty.texi @@ -497,6 +497,13 @@ The base class and its discriminator must be identified using the ``desc'' option. Each concrete subclass must use the ``tag'' option to identify which value of the discriminator it corresponds to. +Every class in the hierarchy must have a @code{GTY(())} marker, as +gengtype will only attempt to parse classes that have such a marker +@footnote{Classes lacking such a marker will not be identified as being +part of the hierarchy, and so the marking routines will not handle them, +leading to a assertion failure within the marking routines due to an +unknown tag value (assuming that assertions are enabled).}. + @smallexample class GTY((desc("%h.kind"), tag("0"))) example_base @{ diff --git a/gcc/gengtype-state.c b/gcc/gengtype-state.c index 1e9fade..fda473a 100644 --- a/gcc/gengtype-state.c +++ b/gcc/gengtype-state.c @@ -1615,6 +1615,8 @@ read_state_struct_type (type_p type) read_state_lang_bitmap (&(type->u.s.bitmap)); read_state_type (&(type->u.s.lang_struct)); read_state_type (&(type->u.s.base_class)); + if (type->u.s.base_class) + add_subclass (type->u.s.base_class, type); } else { diff --git a/gcc/gengtype.c b/gcc/gengtype.c index 31e0f99..f35952e 100644 --- a/gcc/gengtype.c +++ b/gcc/gengtype.c @@ -137,6 +137,16 @@ xasprintf (const char *format, ...) return result; } +/* Locate the ultimate base class of struct S. */ + +static const_type_p +get_ultimate_base_class (const_type_p s) +{ + while (s->u.s.base_class) + s = s->u.s.base_class; + return s; +} + /* Input file handling. */ /* Table of all input files. */ @@ -667,6 +677,16 @@ resolve_typedef (const char *s, struct fileloc *pos) return p; } +/* Add SUBCLASS to head of linked list of BASE's subclasses. */ + +void add_subclass (type_p base, type_p subclass) +{ + gcc_assert (union_or_struct_p (base)); + gcc_assert (union_or_struct_p (subclass)); + + subclass->u.s.next_sibling_class = base->u.s.first_subclass; + base->u.s.first_subclass = subclass; +} /* Create and return a new structure with tag NAME at POS with fields FIELDS and options O. The KIND of structure must be one of @@ -749,6 +769,8 @@ new_structure (const char *name, enum typekind kind, struct fileloc *pos, if (s->u.s.lang_struct) s->u.s.lang_struct->u.s.bitmap |= bitmap; s->u.s.base_class = base_class; + if (base_class) + add_subclass (base_class, s); return s; } @@ -1535,6 +1557,12 @@ set_gc_used_type (type_p t, enum gc_used_enum level, type_p param[NUM_PARAM], if (t->u.s.base_class) set_gc_used_type (t->u.s.base_class, level, param, allow_undefined_types); + /* Anything pointing to a base class might actually be pointing + to a subclass. */ + for (type_p subclass = t->u.s.first_subclass; subclass; + subclass = subclass->u.s.next_sibling_class) + set_gc_used_type (subclass, level, param, + allow_undefined_types); FOR_ALL_INHERITED_FIELDS(t, f) { @@ -2554,8 +2582,7 @@ output_mangled_typename (outf_p of, const_type_p t) /* For references to classes within an inheritance hierarchy, only ever reference the ultimate base class, since only it will have gt_ functions. */ - while (t->u.s.base_class) - t = t->u.s.base_class; + t = get_ultimate_base_class (t); const char *id_for_tag = filter_type_name (t->u.s.tag); oprintf (of, "%lu%s", (unsigned long) strlen (id_for_tag), id_for_tag); @@ -2630,30 +2657,28 @@ get_string_option (options_p opt, const char *key) static void walk_subclasses (type_p base, struct walk_type_data *d) { - for (type_p sub = structures; sub != NULL; sub = sub->next) + for (type_p sub = base->u.s.first_subclass; sub != NULL; + sub = sub->u.s.next_sibling_class) { - if (sub->u.s.base_class == base) + const char *type_tag = get_string_option (sub->u.s.opt, "tag"); + if (type_tag) { - const char *type_tag = get_string_option (sub->u.s.opt, "tag"); - if (type_tag) - { - oprintf (d->of, "%*scase %s:\n", d->indent, "", type_tag); - d->indent += 2; - oprintf (d->of, "%*s{\n", d->indent, ""); - d->indent += 2; - oprintf (d->of, "%*s%s *sub = static_cast <%s *> (x);\n", - d->indent, "", sub->u.s.tag, sub->u.s.tag); - const char *old_val = d->val; - d->val = "(*sub)"; - walk_type (sub, d); - d->val = old_val; - d->indent -= 2; - oprintf (d->of, "%*s}\n", d->indent, ""); - oprintf (d->of, "%*sbreak;\n", d->indent, ""); - d->indent -= 2; - } - walk_subclasses (sub, d); + oprintf (d->of, "%*scase %s:\n", d->indent, "", type_tag); + d->indent += 2; + oprintf (d->of, "%*s{\n", d->indent, ""); + d->indent += 2; + oprintf (d->of, "%*s%s *sub = static_cast <%s *> (x);\n", + d->indent, "", sub->u.s.tag, sub->u.s.tag); + const char *old_val = d->val; + d->val = "(*sub)"; + walk_type (sub, d); + d->val = old_val; + d->indent -= 2; + oprintf (d->of, "%*s}\n", d->indent, ""); + oprintf (d->of, "%*sbreak;\n", d->indent, ""); + d->indent -= 2; } + walk_subclasses (sub, d); } } @@ -3023,6 +3048,20 @@ walk_type (type_p t, struct walk_type_data *d) } else if (desc) { + /* We have a "desc" option on a struct, signifying the + base class within a GC-managed inheritance hierarchy. + The current code specialcases the base class, then walks + into subclasses, recursing into this routine to handle them. + This organization requires the base class to have a case in + the switch statement, and hence a tag value is mandatory + for the base class. This restriction could be removed, but + it would require some restructing of this code. */ + if (!type_tag) + { + error_at_line (d->line, + "missing `tag' option for type `%s'", + t->u.s.tag); + } oprintf (d->of, "%*sswitch (", d->indent, ""); output_escaped_param (d, desc, "desc"); oprintf (d->of, ")\n"); @@ -3188,6 +3227,16 @@ walk_type (type_p t, struct walk_type_data *d) /* Add cases to handle subclasses. */ walk_subclasses (t, d); + /* Ensure that if someone forgets a "tag" option that we don't + silent fail to traverse that subclass's fields. */ + if (!seen_default_p) + { + oprintf (d->of, "%*s/* Unrecognized tag value. */\n", + d->indent, ""); + oprintf (d->of, "%*sdefault: gcc_unreachable (); \n", + d->indent, ""); + } + /* End of the switch statement */ oprintf (d->of, "%*s}\n", d->indent, ""); d->indent -= 2; @@ -3537,10 +3586,23 @@ write_func_for_structure (type_p orig_s, type_p s, type_p *param, options_p opt; struct walk_type_data d; - /* Don't write fns for subclasses, only for the ultimate base class - within an inheritance hierarchy. */ if (s->u.s.base_class) - return; + { + /* Verify that the base class has a "desc", since otherwise + the traversal hooks there won't attempt to visit fields of + subclasses such as this one. */ + const_type_p ubc = get_ultimate_base_class (s); + if ((!opts_have (ubc->u.s.opt, "user") + && !opts_have (ubc->u.s.opt, "desc"))) + error_at_line (&s->u.s.line, + ("'%s' is a subclass of non-GTY(user) GTY class '%s'" + ", but '%s' lacks a discriminator 'desc' option"), + s->u.s.tag, ubc->u.s.tag, ubc->u.s.tag); + + /* Don't write fns for subclasses, only for the ultimate base class + within an inheritance hierarchy. */ + return; + } memset (&d, 0, sizeof (d)); d.of = get_output_file_for_structure (s, param); @@ -4452,7 +4514,7 @@ write_root (outf_p f, pair_p v, type_p type, const char *name, int has_length, case TYPE_POINTER: { - type_p tp; + const_type_p tp; if (!start_root_entry (f, v, name, line)) return; @@ -4461,8 +4523,7 @@ write_root (outf_p f, pair_p v, type_p type, const char *name, int has_length, if (!has_length && union_or_struct_p (tp)) { - while (tp->u.s.base_class) - tp = tp->u.s.base_class; + tp = get_ultimate_base_class (tp); const char *id_for_tag = filter_type_name (tp->u.s.tag); oprintf (f, " >_ggc_mx_%s,\n", id_for_tag); if (emit_pch) diff --git a/gcc/gengtype.h b/gcc/gengtype.h index 2d20bf9..0c3ec96 100644 --- a/gcc/gengtype.h +++ b/gcc/gengtype.h @@ -293,6 +293,15 @@ struct type { type_p lang_struct; type_p base_class; /* the parent class, if any. */ + + /* The following two fields are not serialized in state files, and + are instead reconstructed on load. */ + + /* The head of a singly-linked list of immediate descendents in + the inheritance hierarchy. */ + type_p first_subclass; + /* The next in that list. */ + type_p next_sibling_class; } s; /* when TYPE_SCALAR: */ @@ -424,6 +433,7 @@ extern char *xasprintf (const char *, ...) ATTRIBUTE_PRINTF_1; extern void do_typedef (const char *s, type_p t, struct fileloc *pos); extern void do_scalar_typedef (const char *s, struct fileloc *pos); extern type_p resolve_typedef (const char *s, struct fileloc *pos); +extern void add_subclass (type_p base, type_p subclass); extern type_p new_structure (const char *name, enum typekind kind, struct fileloc *pos, pair_p fields, options_p o, type_p base); |