binutils-gdb/gdb/dictionary.h
Pedro Alves b5ec771e60 Introduce lookup_name_info and generalize Ada's FULL/WILD name matching
Summary:
 - This is preparation for supporting wild name matching on C++ too.
 - This is also preparation for TAB-completion fixes.
 - Makes symbol name matching (think strcmp_iw) be based on a per-language method.
 - Merges completion and non-completion name comparison (think
   language_ops::la_get_symbol_name_cmp generalized).
 - Avoid re-hashing lookup name multiple times
 - Centralizes preparing a name for lookup (Ada name encoding / C++ Demangling),
   both completion and non-completion.
 - Fixes Ada latent bug with verbatim name matches in expressions
 - Makes ada-lang.c use common|symtab.c completion code a bit more.

Ada's wild matching basically means that

 "(gdb) break foo"

will find all methods named "foo" in all packages.  Translating to
C++, it's roughly the same as saying that "break klass::method" sets
breakpoints on all "klass::method" methods of all classes, no matter
the namespace.  A following patch will teach GDB about fullname vs
wild matching for C++ too.  This patch is preparatory work to get
there.

Another idea here is to do symbol name matching based on the symbol
language's algorithm.  I.e., avoid dependency on current language set.

This allows for example doing

  (gdb) b foo::bar< int > (<tab>

and having gdb name match the C++ symbols correctly even if the
current language is C or Assembly (or Rust, or Ada, or ...), which can
easily happen if you step into an Assembly/C runtime library frame.

By encapsulating all the information related to a lookup name in a
class, we can also cache hash computation for a given language in the
lookup name object, to avoid recomputing it over and over.

Similarly, because we don't really know upfront which languages the
lookup name will be matched against, for each language we store the
lookup name transformed into a search name.  E.g., for C++, that means
demangling the name.  But for Ada, it means encoding the name.  This
actually forces us to centralize all the different lookup name
encoding in a central place, resulting in clearer code, IMO.  See
e.g., the new ada_lookup_name_info class.

The lookup name -> symbol search name computation is also done only
once per language.

The old language->la_get_symbol_name_cmp / symbol_name_cmp_ftype are
generalized to work with both completion, and normal symbol look up.

At some point early on, I had separate completion vs non-completion
language vector entry points, but a single method ends up being better
IMO for simplifying things -- the more we merge the completion /
non-completion name lookup code paths, the less changes for bugs
causing completion vs normal lookup finding different symbols.

The ada-lex.l change is necessary because when doing

  (gdb) p <UpperCase>

then the name that is passed to write_ write_var_or_type ->
ada_lookup_symbol_list misses the "<>", i.e., it's just "UpperCase",
and we end up doing a wild match against "UpperCase" lowercased by
ada_lookup_name_info's constructor.  I.e., "uppercase" wouldn't ever
match "UpperCase", and the symbol lookup fails.

This wouldn't cause any regression in the testsuite, but I added a new
test that would pass before the patch and fail after, if it weren't
for that fix.

This is latent bug that happens to go unnoticed because that
particular path was inconsistent with the rest of Ada symbol lookup by
not lowercasing the lookup name.

Ada's symbol_completion_add is deleted, replaced by using common
code's completion_list_add_name.  To make the latter work for Ada, we
needed to add a new output parameter, because Ada wants to return back
a custom completion candidates that are not the symbol name.

With this patch, minimal symbol demangled name hashing is made
consistent with regular symbol hashing.  I.e., it now goes via the
language vector's search_name_hash method too, as I had suggested in a
previous patch.

dw2_expand_symtabs_matching / .gdb_index symbol names were a
challenge.  The problem is that we have no way to telling what is the
language of each symbol name found in the index, until we expand the
corresponding full symbol, which is off course what we're trying to
avoid.  Language information is simply not considered in the index
format...  Since the symbol name hashing and comparison routines are
per-language, we now have a problem.  The patch sorts this out by
matching each name against all languages.  This is inneficient, and
indeed slows down completion several times.  E.g., with:

 $ cat script.cmd
 set pagination off
 set $count = 0
 while $count < 400
   complete b string_prin
   printf "count = %d\n", $count
   set $count = $count + 1
 end

 $ time gdb --batch -q ./gdb-with-index -ex "source script-string_printf.cmd"

I get, before patch (-O2, x86-64):

 real    0m1.773s
 user    0m1.737s
 sys     0m0.040s

While after patch (-O2, x86-64):

 real    0m9.843s
 user    0m9.482s
 sys     0m0.034s

However, the following patch will optimize this, and will actually
make this use case faster compared to the "before patch" above:

 real    0m1.321s
 user    0m1.285s
 sys     0m0.039s

gdb/ChangeLog:
2017-11-08   Pedro Alves  <palves@redhat.com>

	* ada-lang.c (ada_encode): Rename to ..
	(ada_encode_1): ... this.  Add throw_errors parameter and handle
	it.
	(ada_encode): Reimplement.
	(match_name): Delete, folded into full_name.
	(resolve_subexp): No longer pass the encoded name to
	ada_lookup_symbol_list.
	(should_use_wild_match): Delete.
	(name_match_type_from_name): New.
	(ada_lookup_simple_minsym): Use lookup_name_info and the
	language's symbol_name_matcher_ftype.
	(add_symbols_from_enclosing_procs, ada_add_local_symbols)
	(ada_add_block_renamings): Adjust to use lookup_name_info.
	(ada_lookup_name): New.
	(add_nonlocal_symbols, ada_add_all_symbols)
	(ada_lookup_symbol_list_worker, ada_lookup_symbol_list)
	(ada_iterate_over_symbols): Adjust to use lookup_name_info.
	(ada_name_for_lookup): Delete.
	(ada_lookup_encoded_symbol): Construct a verbatim name.
	(wild_match): Reverse sense of return type.  Use bool.
	(full_match): Reverse sense of return type.  Inline bits of old
	match_name here.
	(ada_add_block_symbols): Adjust to use lookup_name_info.
	(symbol_completion_match): Delete, folded into...
	(ada_lookup_name_info::matches): ... .this new method.
	(symbol_completion_add): Delete.
	(ada_collect_symbol_completion_matches): Add name_match_type
	parameter.  Adjust to use lookup_name_info and
	completion_list_add_name.
	(get_var_value, ada_add_global_exceptions): Adjust to use
	lookup_name_info.
	(ada_get_symbol_name_cmp): Delete.
	(do_wild_match, do_full_match): New functions.
	(ada_lookup_name_info::ada_lookup_name_info): New method.
	(ada_symbol_name_matches, ada_get_symbol_name_matcher): New
	functions.
	(ada_language_defn): Install ada_get_symbol_name_matcher.
	* ada-lex.l (processId): If name starts with '<', copy it
	verbatim.
	* block.c (block_iter_match_step, block_iter_match_first)
	(block_iter_match_next, block_lookup_symbol)
	(block_lookup_symbol_primary, block_find_symbol): Adjust to use
	lookup_name_info.
	* block.h (block_iter_match_first, block_iter_match_next)
	(ALL_BLOCK_SYMBOLS_WITH_NAME): Adjust to use lookup_name_info.
	* c-lang.c (c_language_defn, cplus_language_defn)
	(asm_language_defn, minimal_language_defn): Adjust comments to
	refer to la_get_symbol_name_matcher.
	* completer.c (complete_files_symbols)
	(collect_explicit_location_matches, symbol_completer): Pass a
	symbol_name_match_type down.
	* completer.h (class completion_match, completion_match_result):
	New classes.
	(completion_tracker::reset_completion_match_result): New method.
	(completion_tracker::m_completion_match_result): New field.
	* cp-support.c (make_symbol_overload_list_block): Adjust to use
	lookup_name_info.
	(cp_fq_symbol_name_matches, cp_get_symbol_name_matcher): New
	functions.
	* cp-support.h (cp_get_symbol_name_matcher): New declaration.
	* d-lang.c: Adjust comments to refer to
	la_get_symbol_name_matcher.
	* dictionary.c (dict_vector) <iter_match_first, iter_match_next>:
	Adjust to use lookup_name_info.
	(dict_iter_match_first, dict_iter_match_next)
	(iter_match_first_hashed, iter_match_next_hashed)
	(iter_match_first_linear, iter_match_next_linear): Adjust to work
	with a lookup_name_info.
	* dictionary.h (dict_iter_match_first, dict_iter_match_next):
	Likewise.
	* dwarf2read.c (dw2_lookup_symbol): Adjust to use lookup_name_info.
	(dw2_map_matching_symbols): Adjust to use symbol_name_match_type.
	(gdb_index_symbol_name_matcher): New class.
	(dw2_expand_symtabs_matching) Adjust to use lookup_name_info and
	gdb_index_symbol_name_matcher.  Accept a NULL symbol_matcher.
	* f-lang.c (f_collect_symbol_completion_matches): Adjust to work
	with a symbol_name_match_type.
	(f_language_defn): Adjust comments to refer to
	la_get_symbol_name_matcher.
	* go-lang.c (go_language_defn): Adjust comments to refer to
	la_get_symbol_name_matcher.
	* language.c (default_symbol_name_matcher)
	(language_get_symbol_name_matcher): New functions.
	(unknown_language_defn, auto_language_defn): Adjust comments to
	refer to la_get_symbol_name_matcher.
	* language.h (symbol_name_cmp_ftype): Delete.
	(language_defn) <la_collect_symbol_completion_matches>: Add match
	type parameter.
	<la_get_symbol_name_cmp>: Delete field.
	<la_get_symbol_name_matcher>: New field.
	<la_iterate_over_symbols>: Adjust to use lookup_name_info.
	(default_symbol_name_matcher, language_get_symbol_name_matcher):
	Declare.
	* linespec.c (iterate_over_all_matching_symtabs)
	(iterate_over_file_blocks): Adjust to use lookup_name_info.
	(find_methods): Add language parameter, and use lookup_name_info
	and the language's symbol_name_matcher_ftype.
	(linespec_complete_function): Adjust.
	(lookup_prefix_sym): Use lookup_name_info.
	(add_all_symbol_names_from_pspace): Adjust.
	(find_superclass_methods): Add language parameter and pass it
	down.
	(find_method): Pass symbol language down.
	(find_linespec_symbols): Don't demangle or Ada encode here.
	(search_minsyms_for_name): Add lookup_name_info parameter.
	(add_matching_symbols_to_info): Add name_match_type parameter.
	Use lookup_name_info.
	* m2-lang.c (m2_language_defn): Adjust comments to refer to
	la_get_symbol_name_matcher.
	* minsyms.c: Include <algorithm>.
	(add_minsym_to_demangled_hash_table): Remove table parameter and
	add objfile parameter.  Use search_name_hash, and add language to
	demangled languages vector.
	(struct found_minimal_symbols): New struct.
	(lookup_minimal_symbol_mangled, lookup_minimal_symbol_demangled):
	New functions.
	(lookup_minimal_symbol): Adjust to use them.  Don't canonicalize
	input names here.  Use lookup_name_info instead.  Lookup up
	demangled names once for each language in the demangled names
	vector.
	(iterate_over_minimal_symbols): Use lookup_name_info.  Lookup up
	demangled names once for each language in the demangled names
	vector.
	(build_minimal_symbol_hash_tables): Adjust.
	* minsyms.h (iterate_over_minimal_symbols): Adjust to pass down a
	lookup_name_info.
	* objc-lang.c (objc_language_defn): Adjust comment to refer to
	la_get_symbol_name_matcher.
	* objfiles.h: Include <vector>.
	(objfile_per_bfd_storage) <demangled_hash_languages>: New field.
	* opencl-lang.c (opencl_language_defn): Adjust comment to refer to
	la_get_symbol_name_matcher.
	* p-lang.c (pascal_language_defn): Adjust comment to refer to
	la_get_symbol_name_matcher.
	* psymtab.c (psym_lookup_symbol): Use lookup_name_info.
	(match_partial_symbol): Use symbol_name_match_type,
	lookup_name_info and psymbol_name_matches.
	(lookup_partial_symbol): Use lookup_name_info.
	(map_block): Use symbol_name_match_type and lookup_name_info.
	(psym_map_matching_symbols): Use symbol_name_match_type.
	(psymbol_name_matches): New.
	(recursively_search_psymtabs): Use lookup_name_info and
	psymbol_name_matches.  Rename 'kind' parameter to 'domain'.
	(psym_expand_symtabs_matching): Use lookup_name_info.  Rename
	'kind' parameter to 'domain'.
	* rust-lang.c (rust_language_defn): Adjust comment to refer to
	la_get_symbol_name_matcher.
	* symfile-debug.c (debug_qf_map_matching_symbols)
	(debug_qf_map_matching_symbols): Use symbol_name_match_type.
	(debug_qf_expand_symtabs_matching): Use lookup_name_info.
	* symfile.c (expand_symtabs_matching): Use lookup_name_info.
	* symfile.h (quick_symbol_functions) <map_matching_symbols>:
	Adjust to use symbol_name_match_type.
	<expand_symtabs_matching>: Adjust to use lookup_name_info.
	(expand_symtabs_matching): Adjust to use lookup_name_info.
	* symmisc.c (maintenance_expand_symtabs): Use
	lookup_name_info::match_any ().
	* symtab.c (symbol_matches_search_name): New.
	(eq_symbol_entry): Adjust to use lookup_name_info and the
	language's matcher.
	(demangle_for_lookup_info::demangle_for_lookup_info): New.
	(lookup_name_info::match_any): New.
	(iterate_over_symbols, search_symbols): Use lookup_name_info.
	(compare_symbol_name): Add language, lookup_name_info and
	completion_match_result parameters, and use them.
	(completion_list_add_name): Make extern.  Add language and
	lookup_name_info parameters.  Use them.
	(completion_list_add_symbol, completion_list_add_msymbol)
	(completion_list_objc_symbol): Add lookup_name_info parameters and
	adjust.  Pass down language.
	(completion_list_add_fields): Add lookup_name_info parameters and
	adjust.  Pass down language.
	(add_symtab_completions): Add lookup_name_info parameters and
	adjust.
	(default_collect_symbol_completion_matches_break_on): Add
	name_match_type parameter, and use it.  Use lookup_name_info.
	(default_collect_symbol_completion_matches)
	(collect_symbol_completion_matches): Add name_match_type
	parameter, and pass it down.
	(collect_symbol_completion_matches_type): Adjust.
	(collect_file_symbol_completion_matches): Add name_match_type
	parameter, and use lookup_name_info.
	* symtab.h: Include <string> and "common/gdb_optional.h".
	(enum class symbol_name_match_type): New.
	(class ada_lookup_name_info): New.
	(struct demangle_for_lookup_info): New.
	(class lookup_name_info): New.
	(symbol_name_matcher_ftype): New.
	(SYMBOL_MATCHES_SEARCH_NAME): Use symbol_matches_search_name.
	(symbol_matches_search_name): Declare.
	(MSYMBOL_MATCHES_SEARCH_NAME): Delete.
	(default_collect_symbol_completion_matches)
	(collect_symbol_completion_matches)
	(collect_file_symbol_completion_matches): Add name_match_type
	parameter.
	(iterate_over_symbols): Use lookup_name_info.
	(completion_list_add_name): Declare.
	* utils.c (enum class strncmp_iw_mode): Moved to utils.h.
	(strncmp_iw_with_mode): Now extern.
	* utils.h (enum class strncmp_iw_mode): Moved from utils.c.
	(strncmp_iw_with_mode): Declare.

gdb/testsuite/ChangeLog:
2017-11-08   Pedro Alves  <palves@redhat.com>

	* gdb.ada/complete.exp (p <Exported_Capitalized>): New test.
	(p Exported_Capitalized): New test.
	(p exported_capitalized): New test.
2017-11-08 16:02:24 +00:00

168 lines
6.0 KiB
C

/* Routines for name->symbol lookups in GDB.
Copyright (C) 2003-2017 Free Software Foundation, Inc.
Contributed by David Carlton <carlton@bactrian.org> and by Kealia,
Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#ifndef DICTIONARY_H
#define DICTIONARY_H
#include "symfile.h"
/* An opaque type for dictionaries; only dictionary.c should know
about its innards. */
struct dictionary;
/* Other types needed for declarations. */
struct symbol;
struct obstack;
struct pending;
struct language_defn;
/* The creation functions for various implementations of
dictionaries. */
/* Create a dictionary of symbols of language LANGUAGE implemented via
a fixed-size hashtable. All memory it uses is allocated on
OBSTACK; the environment is initialized from SYMBOL_LIST. */
extern struct dictionary *dict_create_hashed (struct obstack *obstack,
enum language language,
const struct pending
*symbol_list);
/* Create a dictionary of symbols of language LANGUAGE, implemented
via a hashtable that grows as necessary. The dictionary is
initially empty; to add symbols to it, call dict_add_symbol().
Call dict_free() when you're done with it. */
extern struct dictionary *
dict_create_hashed_expandable (enum language language);
/* Create a dictionary of symbols of language LANGUAGE, implemented
via a fixed-size array. All memory it uses is allocated on
OBSTACK; the environment is initialized from the SYMBOL_LIST. The
symbols are ordered in the same order that they're found in
SYMBOL_LIST. */
extern struct dictionary *dict_create_linear (struct obstack *obstack,
enum language language,
const struct pending
*symbol_list);
/* Create a dictionary of symbols of language LANGUAGE, implemented
via an array that grows as necessary. The dictionary is initially
empty; to add symbols to it, call dict_add_symbol(). Call
dict_free() when you're done with it. */
extern struct dictionary *
dict_create_linear_expandable (enum language language);
/* The functions providing the interface to dictionaries. Note that
the most common parts of the interface, namely symbol lookup, are
only provided via iterator functions. */
/* Free the memory used by a dictionary that's not on an obstack. (If
any.) */
extern void dict_free (struct dictionary *dict);
/* Add a symbol to an expandable dictionary. */
extern void dict_add_symbol (struct dictionary *dict, struct symbol *sym);
/* Utility to add a list of symbols to a dictionary. */
extern void dict_add_pending (struct dictionary *dict,
const struct pending *symbol_list);
/* Is the dictionary empty? */
extern int dict_empty (struct dictionary *dict);
/* A type containing data that is used when iterating over all symbols
in a dictionary. Don't ever look at its innards; this type would
be opaque if we didn't need to be able to allocate it on the
stack. */
struct dict_iterator
{
/* The dictionary that this iterator is associated to. */
const struct dictionary *dict;
/* The next two members are data that is used in a way that depends
on DICT's implementation type. */
int index;
struct symbol *current;
};
/* Initialize ITERATOR to point at the first symbol in DICT, and
return that first symbol, or NULL if DICT is empty. */
extern struct symbol *dict_iterator_first (const struct dictionary *dict,
struct dict_iterator *iterator);
/* Advance ITERATOR, and return the next symbol, or NULL if there are
no more symbols. Don't call this if you've previously received
NULL from dict_iterator_first or dict_iterator_next on this
iteration. */
extern struct symbol *dict_iterator_next (struct dict_iterator *iterator);
/* Initialize ITERATOR to point at the first symbol in DICT whose
SYMBOL_SEARCH_NAME is NAME, as tested using COMPARE (which must use
the same conventions as strcmp_iw and be compatible with any
dictionary hashing function), and return that first symbol, or NULL
if there are no such symbols. */
extern struct symbol *dict_iter_match_first (const struct dictionary *dict,
const lookup_name_info &name,
struct dict_iterator *iterator);
/* Advance ITERATOR to point at the next symbol in DICT whose
SYMBOL_SEARCH_NAME is NAME, as tested using COMPARE (see
dict_iter_match_first), or NULL if there are no more such symbols.
Don't call this if you've previously received NULL from
dict_iterator_match_first or dict_iterator_match_next on this
iteration. And don't call it unless ITERATOR was created by a
previous call to dict_iter_match_first with the same NAME and COMPARE. */
extern struct symbol *dict_iter_match_next (const lookup_name_info &name,
struct dict_iterator *iterator);
/* Return some notion of the size of the dictionary: the number of
symbols if we have that, the number of hash buckets otherwise. */
extern int dict_size (const struct dictionary *dict);
/* Macro to loop through all symbols in a dictionary DICT, in no
particular order. ITER is a struct dict_iterator (NOTE: __not__ a
struct dict_iterator *), and SYM points to the current symbol.
It's implemented as a single loop, so you can terminate the loop
early by a break if you desire. */
#define ALL_DICT_SYMBOLS(dict, iter, sym) \
for ((sym) = dict_iterator_first ((dict), &(iter)); \
(sym); \
(sym) = dict_iterator_next (&(iter)))
#endif /* DICTIONARY_H */