| Message ID | 20241008183823.36676-31-samitolvanen@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Implement DWARF modversions | expand |
On 10/8/24 20:38, Sami Tolvanen wrote: > Expand each structure type only once per exported symbol. This > is necessary to support self-referential structures, which would > otherwise result in infinite recursion, but is still sufficient for > catching ABI changes. > > For pointers, limit structure expansion after the first pointer > in the symbol type. This should be plenty for detecting ABI > differences, but it stops us from pulling in half the kernel for > types that contain pointers to large kernel data structures, like > task_struct, for example. > > Signed-off-by: Sami Tolvanen <samitolvanen@google.com> > Acked-by: Neal Gompa <neal@gompa.dev> > --- > scripts/gendwarfksyms/Makefile | 1 + > scripts/gendwarfksyms/cache.c | 44 +++++++++++ > scripts/gendwarfksyms/dwarf.c | 109 +++++++++++++++++++++++--- > scripts/gendwarfksyms/gendwarfksyms.h | 37 +++++++++ > 4 files changed, 182 insertions(+), 9 deletions(-) > create mode 100644 scripts/gendwarfksyms/cache.c > > diff --git a/scripts/gendwarfksyms/Makefile b/scripts/gendwarfksyms/Makefile > index c0d4ce50fc27..c06145d84df8 100644 > --- a/scripts/gendwarfksyms/Makefile > +++ b/scripts/gendwarfksyms/Makefile > @@ -2,6 +2,7 @@ > hostprogs-always-y += gendwarfksyms > > gendwarfksyms-objs += gendwarfksyms.o > +gendwarfksyms-objs += cache.o > gendwarfksyms-objs += die.o > gendwarfksyms-objs += dwarf.o > gendwarfksyms-objs += symbols.o > diff --git a/scripts/gendwarfksyms/cache.c b/scripts/gendwarfksyms/cache.c > new file mode 100644 > index 000000000000..2f1517133a20 > --- /dev/null > +++ b/scripts/gendwarfksyms/cache.c > @@ -0,0 +1,44 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (C) 2024 Google LLC > + */ > + > +#include "gendwarfksyms.h" > + > +struct expanded { > + uintptr_t addr; > + struct hlist_node hash; > +}; > + > +void __cache_mark_expanded(struct expansion_cache *ec, uintptr_t addr) > +{ > + struct expanded *es; > + > + es = xmalloc(sizeof(struct expanded)); > + es->addr = addr; > + hash_add(ec->cache, &es->hash, addr_hash(addr)); > +} > + > +bool __cache_was_expanded(struct expansion_cache *ec, uintptr_t addr) > +{ > + struct expanded *es; > + > + hash_for_each_possible(ec->cache, es, hash, addr_hash(addr)) { > + if (es->addr == addr) > + return true; > + } > + > + return false; > +} > + > +void cache_clear_expanded(struct expansion_cache *ec) > +{ > + struct hlist_node *tmp; > + struct expanded *es; > + > + hash_for_each_safe(ec->cache, es, tmp, hash) { > + free(es); > + } > + > + hash_init(ec->cache); > +} > diff --git a/scripts/gendwarfksyms/dwarf.c b/scripts/gendwarfksyms/dwarf.c > index f5cebbdcc212..51dd8e82f9e7 100644 > --- a/scripts/gendwarfksyms/dwarf.c > +++ b/scripts/gendwarfksyms/dwarf.c > @@ -26,6 +26,7 @@ static void process_linebreak(struct die *cache, int n) > !dwarf_form##attr(&da, value); \ > } > > +DEFINE_GET_ATTR(flag, bool) > DEFINE_GET_ATTR(udata, Dwarf_Word) > > static bool get_ref_die_attr(Dwarf_Die *die, unsigned int id, Dwarf_Die *value) > @@ -79,6 +80,13 @@ static bool match_export_symbol(struct state *state, Dwarf_Die *die) > return !!state->sym; > } > > +static bool is_declaration(Dwarf_Die *die) > +{ > + bool value; > + > + return get_flag_attr(die, DW_AT_declaration, &value) && value; > +} > + > /* > * Type string processing > */ > @@ -455,19 +463,28 @@ static void __process_structure_type(struct state *state, struct die *cache, > die_callback_t process_func, > die_match_callback_t match_func) > { > + bool is_decl; > + > process(cache, type); > process_fqn(cache, die); > process(cache, " {"); > process_linebreak(cache, 1); > > - check(process_die_container(state, cache, die, process_func, > - match_func)); > + is_decl = is_declaration(die); > + > + if (!is_decl && state->expand.expand) { > + cache_mark_expanded(&state->expansion_cache, die->addr); > + check(process_die_container(state, cache, die, process_func, > + match_func)); > + } > > process_linebreak(cache, -1); > process(cache, "}"); > > - process_byte_size_attr(cache, die); > - process_alignment_attr(cache, die); > + if (!is_decl && state->expand.expand) { > + process_byte_size_attr(cache, die); > + process_alignment_attr(cache, die); > + } > } > > #define DEFINE_PROCESS_STRUCTURE_TYPE(structure) \ > @@ -520,7 +537,7 @@ static void process_unspecified_type(struct state *state, struct die *cache, > Dwarf_Die *die) > { > /* > - * These can be emitted for stand-elone assembly code, which means we > + * These can be emitted for stand-alone assembly code, which means we > * might run into them in vmlinux.o. > */ > process(cache, "unspecified_type"); Nit: This hunk should be folded into patch #9 ("gendwarfksyms: Expand structure types"). > @@ -552,6 +569,42 @@ static void process_cached(struct state *state, struct die *cache, > } > } > > +static void state_init(struct state *state) > +{ > + state->expand.expand = true; > + state->expand.ptr_depth = 0; > + state->expand.ptr_expansion_depth = 0; > + hash_init(state->expansion_cache.cache); > +} > + > +static void expansion_state_restore(struct expansion_state *state, > + struct expansion_state *saved) > +{ > + state->expand = saved->expand; > + state->ptr_depth = saved->ptr_depth; > + state->ptr_expansion_depth = saved->ptr_expansion_depth; > +} > + > +static void expansion_state_save(struct expansion_state *state, > + struct expansion_state *saved) > +{ > + expansion_state_restore(saved, state); > +} > + > +static bool is_pointer_type(int tag) > +{ > + return tag == DW_TAG_pointer_type || tag == DW_TAG_reference_type; > +} > + > +static bool is_expanded_type(int tag) > +{ > + return tag == DW_TAG_class_type || tag == DW_TAG_structure_type || > + tag == DW_TAG_union_type || tag == DW_TAG_enumeration_type; > +} > + > +/* The maximum depth for expanding structures in pointers */ > +#define MAX_POINTER_EXPANSION_DEPTH 2 > + > #define PROCESS_TYPE(type) \ > case DW_TAG_##type##_type: \ > process_##type##_type(state, cache, die); \ > @@ -559,18 +612,52 @@ static void process_cached(struct state *state, struct die *cache, > > static int process_type(struct state *state, struct die *parent, Dwarf_Die *die) > { > + enum die_state want_state = DIE_COMPLETE; > struct die *cache; > + struct expansion_state saved; > int tag = dwarf_tag(die); > > + expansion_state_save(&state->expand, &saved); > + > + /* > + * Structures and enumeration types are expanded only once per > + * exported symbol. This is sufficient for detecting ABI changes > + * within the structure. > + * > + * We fully expand the first pointer reference in the exported > + * symbol, but limit the expansion of further pointer references > + * to at most MAX_POINTER_EXPANSION_DEPTH levels. > + */ > + if (is_pointer_type(tag)) > + state->expand.ptr_depth++; > + > + if (state->expand.ptr_depth > 0 && is_expanded_type(tag)) { > + if (state->expand.ptr_expansion_depth >= > + MAX_POINTER_EXPANSION_DEPTH || > + cache_was_expanded(&state->expansion_cache, die->addr)) > + state->expand.expand = false; > + > + if (state->expand.expand) > + state->expand.ptr_expansion_depth++; > + } > + > /* > - * If we have the DIE already cached, use it instead of walking > + * If we have want_state already cached, use it instead of walking > * through DWARF. > */ > - cache = die_map_get(die, DIE_COMPLETE); > + if (!state->expand.expand && is_expanded_type(tag)) > + want_state = DIE_UNEXPANDED; > + > + cache = die_map_get(die, want_state); > + > + if (cache->state == want_state) { > + if (want_state == DIE_COMPLETE && is_expanded_type(tag)) > + cache_mark_expanded(&state->expansion_cache, die->addr); > > - if (cache->state == DIE_COMPLETE) { > process_cached(state, cache, die); > die_map_add_die(parent, cache); > + > + expansion_state_restore(&state->expand, &saved); > return 0; > } > The commit message and the comment in process_type() describe that each structure type should be expanded only once per symbol, but that doesn't seem to be the case? Consider the following example: struct A { int m; }; void foo(struct A a1, struct A a2) {} Running gendwarfksyms on the compiled file shows the following debug output: $ echo foo | ./build/scripts/gendwarfksyms/gendwarfksyms --debug --dump-types --dump-versions --dump-dies test.o [...] gendwarfksyms: process_symbol: foo subprogram ( formal_parameter structure_type A { member base_type int byte_size(4) encoding(5) m data_member_location(0) } byte_size(4) a1 , formal_parameter structure_type A { member base_type int byte_size(4) encoding(5) m data_member_location(0) } byte_size(4) a2 ) -> base_type void I think it indicates that struct A was expanded twice. My expectation would be to see: gendwarfksyms: process_symbol: foo subprogram ( formal_parameter structure_type A { member base_type int byte_size(4) encoding(5) m data_member_location(0) } byte_size(4) a1 , formal_parameter structure_type A { } a2 ) -> base_type void If I follow correctly, the type_expand() logic on the output eventually performs only the first expansion for the CRC calculation. However, it looks this process_type() code should do the same, if only to be a bit faster. Or did I misunderstand anything how this should work? I played with the following (applies on the top of the series), which matches my understanding of what should happen: diff --git a/scripts/gendwarfksyms/dwarf.c b/scripts/gendwarfksyms/dwarf.c index 0112b5e8fbf5..1cc39be02b80 100644 --- a/scripts/gendwarfksyms/dwarf.c +++ b/scripts/gendwarfksyms/dwarf.c @@ -661,7 +661,6 @@ static void __process_structure_type(struct state *state, struct die *cache, is_decl = is_declaration(cache, die); if (!is_decl && state->expand.expand) { - cache_mark_expanded(&state->expansion_cache, die->addr); state->expand.current_fqn = cache->fqn; check(process_die_container(state, cache, die, process_func, match_func)); @@ -850,32 +849,35 @@ static int process_type(struct state *state, struct die *parent, Dwarf_Die *die) if (is_pointer_type(tag)) state->expand.ptr_depth++; - if (state->expand.ptr_depth > 0 && is_expanded_type(tag)) { - if (state->expand.ptr_expansion_depth >= - MAX_POINTER_EXPANSION_DEPTH || - cache_was_expanded(&state->expansion_cache, die->addr)) + if (is_expanded_type(tag)) { + if (cache_was_expanded(&state->expansion_cache, die->addr)) state->expand.expand = false; + if (state->expand.ptr_depth > 0) { + if (state->expand.ptr_expansion_depth >= + MAX_POINTER_EXPANSION_DEPTH) + state->expand.expand = false; + + if (state->expand.expand) + state->expand.ptr_expansion_depth++; + } + if (state->expand.expand) - state->expand.ptr_expansion_depth++; + cache_mark_expanded(&state->expansion_cache, die->addr); + else + want_state = DIE_UNEXPANDED; } /* * If we have want_state already cached, use it instead of walking * through DWARF. */ - if (!state->expand.expand && is_expanded_type(tag)) - want_state = DIE_UNEXPANDED; - cache = die_map_get(die, want_state); if (cache->state == want_state) { die_debug_g("cached addr %p tag %x -- %s", die->addr, tag, die_state_name(cache->state)); - if (want_state == DIE_COMPLETE && is_expanded_type(tag)) - cache_mark_expanded(&state->expansion_cache, die->addr); - process_cached(state, cache, die); die_map_add_die(parent, cache); > @@ -611,9 +698,10 @@ static int process_type(struct state *state, struct die *parent, Dwarf_Die *die) > > /* Update cache state and append to the parent (if any) */ > cache->tag = tag; > - cache->state = DIE_COMPLETE; > + cache->state = want_state; > die_map_add_die(parent, cache); > > + expansion_state_restore(&state->expand, &saved); > return 0; > } > > @@ -675,11 +763,14 @@ static int process_exported_symbols(struct state *unused, struct die *cache, > if (!match_export_symbol(&state, die)) > return 0; > > + state_init(&state); > + > if (tag == DW_TAG_subprogram) > process_subprogram(&state, &state.die); > else > process_variable(&state, &state.die); > > + cache_clear_expanded(&state.expansion_cache); > return 0; > } > default: > diff --git a/scripts/gendwarfksyms/gendwarfksyms.h b/scripts/gendwarfksyms/gendwarfksyms.h > index f317de5b0653..6147859ae2af 100644 > --- a/scripts/gendwarfksyms/gendwarfksyms.h > +++ b/scripts/gendwarfksyms/gendwarfksyms.h > @@ -104,6 +104,7 @@ struct symbol *symbol_get(const char *name); > > enum die_state { > DIE_INCOMPLETE, > + DIE_UNEXPANDED, > DIE_COMPLETE, > DIE_LAST = DIE_COMPLETE > }; > @@ -133,6 +134,7 @@ static inline const char *die_state_name(enum die_state state) > { > switch (state) { > CASE_CONST_TO_STR(DIE_INCOMPLETE) > + CASE_CONST_TO_STR(DIE_UNEXPANDED) > CASE_CONST_TO_STR(DIE_COMPLETE) > } > > @@ -155,9 +157,40 @@ void die_map_add_linebreak(struct die *pd, int linebreak); > void die_map_add_die(struct die *pd, struct die *child); > void die_map_free(void); > > +/* > + * cache.c > + */ > + > +#define EXPANSION_CACHE_HASH_BITS 11 > + > +/* A cache for addresses we've already seen. */ > +struct expansion_cache { > + HASHTABLE_DECLARE(cache, 1 << EXPANSION_CACHE_HASH_BITS); > +}; > + > +void __cache_mark_expanded(struct expansion_cache *ec, uintptr_t addr); > +bool __cache_was_expanded(struct expansion_cache *ec, uintptr_t addr); > + > +static inline void cache_mark_expanded(struct expansion_cache *ec, void *addr) > +{ > + __cache_mark_expanded(ec, (uintptr_t)addr); > +} > + > +static inline bool cache_was_expanded(struct expansion_cache *ec, void *addr) > +{ > + return __cache_was_expanded(ec, (uintptr_t)addr); > +} > + > +void cache_clear_expanded(struct expansion_cache *ec); > + > /* > * dwarf.c > */ > +struct expansion_state { > + bool expand; > + unsigned int ptr_depth; > + unsigned int ptr_expansion_depth; > +}; > > struct state { > struct symbol *sym; > @@ -165,6 +198,10 @@ struct state { > > /* List expansion */ > bool first_list_item; > + > + /* Structure expansion */ > + struct expansion_state expand; > + struct expansion_cache expansion_cache; > }; > > typedef int (*die_callback_t)(struct state *state, struct die *cache,
Hi Petr, On Wed, Oct 16, 2024 at 2:16 PM Petr Pavlu <petr.pavlu@suse.com> wrote: > > On 10/8/24 20:38, Sami Tolvanen wrote: > > /* > > - * These can be emitted for stand-elone assembly code, which means we > > + * These can be emitted for stand-alone assembly code, which means we > > * might run into them in vmlinux.o. > > */ > > process(cache, "unspecified_type"); > > Nit: This hunk should be folded into patch #9 ("gendwarfksyms: Expand > structure types"). Oops, I'll fix this in the next version. > The commit message and the comment in process_type() describe that each > structure type should be expanded only once per symbol, but that doesn't > seem to be the case? Yup, it looks like I messed up the logic here. The ptr_depth check should be later. > If I follow correctly, the type_expand() logic on the output eventually > performs only the first expansion for the CRC calculation. However, it > looks this process_type() code should do the same, if only to be a bit > faster. Or did I misunderstand anything how this should work? > > I played with the following (applies on the top of the series), which > matches my understanding of what should happen: This looks correct to me, and do I like the way you cleaned this up. I'll apply this to v5. Thanks! Sami
diff --git a/scripts/gendwarfksyms/Makefile b/scripts/gendwarfksyms/Makefile index c0d4ce50fc27..c06145d84df8 100644 --- a/scripts/gendwarfksyms/Makefile +++ b/scripts/gendwarfksyms/Makefile @@ -2,6 +2,7 @@ hostprogs-always-y += gendwarfksyms gendwarfksyms-objs += gendwarfksyms.o +gendwarfksyms-objs += cache.o gendwarfksyms-objs += die.o gendwarfksyms-objs += dwarf.o gendwarfksyms-objs += symbols.o diff --git a/scripts/gendwarfksyms/cache.c b/scripts/gendwarfksyms/cache.c new file mode 100644 index 000000000000..2f1517133a20 --- /dev/null +++ b/scripts/gendwarfksyms/cache.c @@ -0,0 +1,44 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2024 Google LLC + */ + +#include "gendwarfksyms.h" + +struct expanded { + uintptr_t addr; + struct hlist_node hash; +}; + +void __cache_mark_expanded(struct expansion_cache *ec, uintptr_t addr) +{ + struct expanded *es; + + es = xmalloc(sizeof(struct expanded)); + es->addr = addr; + hash_add(ec->cache, &es->hash, addr_hash(addr)); +} + +bool __cache_was_expanded(struct expansion_cache *ec, uintptr_t addr) +{ + struct expanded *es; + + hash_for_each_possible(ec->cache, es, hash, addr_hash(addr)) { + if (es->addr == addr) + return true; + } + + return false; +} + +void cache_clear_expanded(struct expansion_cache *ec) +{ + struct hlist_node *tmp; + struct expanded *es; + + hash_for_each_safe(ec->cache, es, tmp, hash) { + free(es); + } + + hash_init(ec->cache); +} diff --git a/scripts/gendwarfksyms/dwarf.c b/scripts/gendwarfksyms/dwarf.c index f5cebbdcc212..51dd8e82f9e7 100644 --- a/scripts/gendwarfksyms/dwarf.c +++ b/scripts/gendwarfksyms/dwarf.c @@ -26,6 +26,7 @@ static void process_linebreak(struct die *cache, int n) !dwarf_form##attr(&da, value); \ } +DEFINE_GET_ATTR(flag, bool) DEFINE_GET_ATTR(udata, Dwarf_Word) static bool get_ref_die_attr(Dwarf_Die *die, unsigned int id, Dwarf_Die *value) @@ -79,6 +80,13 @@ static bool match_export_symbol(struct state *state, Dwarf_Die *die) return !!state->sym; } +static bool is_declaration(Dwarf_Die *die) +{ + bool value; + + return get_flag_attr(die, DW_AT_declaration, &value) && value; +} + /* * Type string processing */ @@ -455,19 +463,28 @@ static void __process_structure_type(struct state *state, struct die *cache, die_callback_t process_func, die_match_callback_t match_func) { + bool is_decl; + process(cache, type); process_fqn(cache, die); process(cache, " {"); process_linebreak(cache, 1); - check(process_die_container(state, cache, die, process_func, - match_func)); + is_decl = is_declaration(die); + + if (!is_decl && state->expand.expand) { + cache_mark_expanded(&state->expansion_cache, die->addr); + check(process_die_container(state, cache, die, process_func, + match_func)); + } process_linebreak(cache, -1); process(cache, "}"); - process_byte_size_attr(cache, die); - process_alignment_attr(cache, die); + if (!is_decl && state->expand.expand) { + process_byte_size_attr(cache, die); + process_alignment_attr(cache, die); + } } #define DEFINE_PROCESS_STRUCTURE_TYPE(structure) \ @@ -520,7 +537,7 @@ static void process_unspecified_type(struct state *state, struct die *cache, Dwarf_Die *die) { /* - * These can be emitted for stand-elone assembly code, which means we + * These can be emitted for stand-alone assembly code, which means we * might run into them in vmlinux.o. */ process(cache, "unspecified_type"); @@ -552,6 +569,42 @@ static void process_cached(struct state *state, struct die *cache, } } +static void state_init(struct state *state) +{ + state->expand.expand = true; + state->expand.ptr_depth = 0; + state->expand.ptr_expansion_depth = 0; + hash_init(state->expansion_cache.cache); +} + +static void expansion_state_restore(struct expansion_state *state, + struct expansion_state *saved) +{ + state->expand = saved->expand; + state->ptr_depth = saved->ptr_depth; + state->ptr_expansion_depth = saved->ptr_expansion_depth; +} + +static void expansion_state_save(struct expansion_state *state, + struct expansion_state *saved) +{ + expansion_state_restore(saved, state); +} + +static bool is_pointer_type(int tag) +{ + return tag == DW_TAG_pointer_type || tag == DW_TAG_reference_type; +} + +static bool is_expanded_type(int tag) +{ + return tag == DW_TAG_class_type || tag == DW_TAG_structure_type || + tag == DW_TAG_union_type || tag == DW_TAG_enumeration_type; +} + +/* The maximum depth for expanding structures in pointers */ +#define MAX_POINTER_EXPANSION_DEPTH 2 + #define PROCESS_TYPE(type) \ case DW_TAG_##type##_type: \ process_##type##_type(state, cache, die); \ @@ -559,18 +612,52 @@ static void process_cached(struct state *state, struct die *cache, static int process_type(struct state *state, struct die *parent, Dwarf_Die *die) { + enum die_state want_state = DIE_COMPLETE; struct die *cache; + struct expansion_state saved; int tag = dwarf_tag(die); + expansion_state_save(&state->expand, &saved); + + /* + * Structures and enumeration types are expanded only once per + * exported symbol. This is sufficient for detecting ABI changes + * within the structure. + * + * We fully expand the first pointer reference in the exported + * symbol, but limit the expansion of further pointer references + * to at most MAX_POINTER_EXPANSION_DEPTH levels. + */ + if (is_pointer_type(tag)) + state->expand.ptr_depth++; + + if (state->expand.ptr_depth > 0 && is_expanded_type(tag)) { + if (state->expand.ptr_expansion_depth >= + MAX_POINTER_EXPANSION_DEPTH || + cache_was_expanded(&state->expansion_cache, die->addr)) + state->expand.expand = false; + + if (state->expand.expand) + state->expand.ptr_expansion_depth++; + } + /* - * If we have the DIE already cached, use it instead of walking + * If we have want_state already cached, use it instead of walking * through DWARF. */ - cache = die_map_get(die, DIE_COMPLETE); + if (!state->expand.expand && is_expanded_type(tag)) + want_state = DIE_UNEXPANDED; + + cache = die_map_get(die, want_state); + + if (cache->state == want_state) { + if (want_state == DIE_COMPLETE && is_expanded_type(tag)) + cache_mark_expanded(&state->expansion_cache, die->addr); - if (cache->state == DIE_COMPLETE) { process_cached(state, cache, die); die_map_add_die(parent, cache); + + expansion_state_restore(&state->expand, &saved); return 0; } @@ -611,9 +698,10 @@ static int process_type(struct state *state, struct die *parent, Dwarf_Die *die) /* Update cache state and append to the parent (if any) */ cache->tag = tag; - cache->state = DIE_COMPLETE; + cache->state = want_state; die_map_add_die(parent, cache); + expansion_state_restore(&state->expand, &saved); return 0; } @@ -675,11 +763,14 @@ static int process_exported_symbols(struct state *unused, struct die *cache, if (!match_export_symbol(&state, die)) return 0; + state_init(&state); + if (tag == DW_TAG_subprogram) process_subprogram(&state, &state.die); else process_variable(&state, &state.die); + cache_clear_expanded(&state.expansion_cache); return 0; } default: diff --git a/scripts/gendwarfksyms/gendwarfksyms.h b/scripts/gendwarfksyms/gendwarfksyms.h index f317de5b0653..6147859ae2af 100644 --- a/scripts/gendwarfksyms/gendwarfksyms.h +++ b/scripts/gendwarfksyms/gendwarfksyms.h @@ -104,6 +104,7 @@ struct symbol *symbol_get(const char *name); enum die_state { DIE_INCOMPLETE, + DIE_UNEXPANDED, DIE_COMPLETE, DIE_LAST = DIE_COMPLETE }; @@ -133,6 +134,7 @@ static inline const char *die_state_name(enum die_state state) { switch (state) { CASE_CONST_TO_STR(DIE_INCOMPLETE) + CASE_CONST_TO_STR(DIE_UNEXPANDED) CASE_CONST_TO_STR(DIE_COMPLETE) } @@ -155,9 +157,40 @@ void die_map_add_linebreak(struct die *pd, int linebreak); void die_map_add_die(struct die *pd, struct die *child); void die_map_free(void); +/* + * cache.c + */ + +#define EXPANSION_CACHE_HASH_BITS 11 + +/* A cache for addresses we've already seen. */ +struct expansion_cache { + HASHTABLE_DECLARE(cache, 1 << EXPANSION_CACHE_HASH_BITS); +}; + +void __cache_mark_expanded(struct expansion_cache *ec, uintptr_t addr); +bool __cache_was_expanded(struct expansion_cache *ec, uintptr_t addr); + +static inline void cache_mark_expanded(struct expansion_cache *ec, void *addr) +{ + __cache_mark_expanded(ec, (uintptr_t)addr); +} + +static inline bool cache_was_expanded(struct expansion_cache *ec, void *addr) +{ + return __cache_was_expanded(ec, (uintptr_t)addr); +} + +void cache_clear_expanded(struct expansion_cache *ec); + /* * dwarf.c */ +struct expansion_state { + bool expand; + unsigned int ptr_depth; + unsigned int ptr_expansion_depth; +}; struct state { struct symbol *sym; @@ -165,6 +198,10 @@ struct state { /* List expansion */ bool first_list_item; + + /* Structure expansion */ + struct expansion_state expand; + struct expansion_cache expansion_cache; }; typedef int (*die_callback_t)(struct state *state, struct die *cache,