binutils-gdb/gdb/linespec.h
Pedro Alves a20714ff39 Make "break foo" find "A::foo", A::B::foo", etc. [C++ and wild matching]
This patch teaches GDB about setting breakpoints in all scopes
(namespaces and classes) by default.

Here's a contrived example:

  (gdb) b func<tab>
  (anonymous namespace)::A::function()            Bn::(anonymous namespace)::B::function()        function(int, int)
  (anonymous namespace)::B::function()            Bn::(anonymous namespace)::function()           gdb::(anonymous namespace)::A::function()
  (anonymous namespace)::B::function() const      Bn::(anonymous namespace)::function(int, int)   gdb::(anonymous namespace)::function()
  (anonymous namespace)::function()               Bn::B::func()                                   gdb::(anonymous namespace)::function(int, int)
  (anonymous namespace)::function(int, int)       Bn::B::function()                               gdb::A::func()
  A::func()                                       Bn::func()                                      gdb::A::function()
  A::function()                                   Bn::function()                                  gdb::func()
  B::func()                                       Bn::function(int, int)                          gdb::function()
  B::function()                                   Bn::function(long)                              gdb::function(int, int)
  B::function() const                             func()                                          gdb::function(long)
  B::function_const() const                       function()
  (gdb) b function
  Breakpoint 1 at 0x4005ce: function. (26 locations)

  (gdb) b B::function<tab>
  (anonymous namespace)::B::function()        B::function() const                         Bn::B::function()
  (anonymous namespace)::B::function() const  B::function_const() const
  B::function()                               Bn::(anonymous namespace)::B::function()
  (gdb) b B::function
  Breakpoint 1 at 0x40072c: B::function. (6 locations)

To get back the original behavior of interpreting the function name as
a fully-qualified name, you can use the new "-qualified" (or "-q")
option/flag (added by this commit).  For example:

 (gdb) b B::function
 (anonymous namespace)::B::function()        B::function() const                         Bn::B::function()
 (anonymous namespace)::B::function() const  B::function_const() const
 B::function()                               Bn::(anonymous namespace)::B::function()

vs:

 (gdb) b -qualified B::function
 B::function()              B::function() const        B::function_const() const

I've chosen "-qualified" / "-q" because "-f" (for "full" or
"fully-qualified") is already taken for "-function".

Note: the "-qualified" option works with both linespecs and explicit
locations.  I.e., these are equivalent:

 (gdb) b -q func
 (gdb) b -q -f func

and so are these:

 (gdb) b -q filename.cc:func
 (gdb) b -q -s filename.cc -f func
 (gdb) b -s filename.cc -q -f func
 (gdb) b -s filename.cc -f func -q

To better understand why I consider wild matching the better default,
consider what happens when we get to the point when _all_ of GDB is
wrapped under "namespace gdb {}".  I have a patch series that does
that, and when I started debugging that GDB, I immediately became
frustrated.  You'd have to write "b gdb::internal_error", "b
gdb::foo", "b gdb::bar", etc. etc., which gets annoying pretty
quickly.  OTOH, consider how this makes it very easy to set
breakpoints in classes wrapped in anonymous namespaces.  You just
don't think of them, GDB finds the symbols for you automatically.

(At the Cauldron a couple months ago, several people told me that they
run into a similar issue when debugging other C++ projects.  One
example was when debugging LLVM, which puts all its code under the
"llvm" namespace.)

Implementation-wise, what the patch does is:

  - makes C++ symbol name hashing only consider the last component of
    a symbol name. (so that we can look up symbol names by
    last-component name only).

  - adds a C++ symbol name matcher for symbol_name_match_type::WILD,
    which ignores missing leading specifiers / components.

  - adjusts a few preexisting testsuite tests to use "-qualified" when
    they mean it.

  - adds new testsuite tests.

  - adds unit tests.

Grows the gdb.linespec/ tests like this:

  -# of expected passes           7823
  +# of expected passes           8977

gdb/ChangeLog:
2017-11-29  Pedro Alves  <palves@redhat.com>

	* NEWS: Mention that breakpoints on C++ functions are now set on
	on all namespaces/classes by default, and mention "break
	-qualified".
	* ax-gdb.c (agent_command_1): Adjust to pass a
	symbol_name_match_type to new_linespec_location.
	* breakpoint.c (parse_breakpoint_sals): Adjust to
	get_linespec_location's return type change.
	(strace_marker_create_sals_from_location): Adjust to pass a
	symbol_name_match_type to new_linespec_location.
	(strace_marker_decode_location): Adjust to get_linespec_location's
	return type change.
	(strace_command): Adjust to pass a symbol_name_match_type to
	new_linespec_location.
	(LOCATION_HELP_STRING): Add paragraph about wildmatching, and
	mention "-qualified".
	* c-lang.c (cplus_language_defn): Install cp_search_name_hash.
	* completer.c (explicit_location_match_type::MATCH_QUALIFIED): New
	enumerator.
	(complete_address_and_linespec_locations): New parameter
	'match_type'.  Pass it down.
	(explicit_options): Add "-qualified".
	(collect_explicit_location_matches): Pass the requested match type
	to the linespec completers.  Handle MATCH_QUALIFIED.
	(location_completer): Handle "-qualified" combined with linespecs.
	* cp-support.c (cp_search_name_hash): New.
	(cp_symbol_name_matches_1): Implement wild matching for C++.
	(cp_fq_symbol_name_matches): Reimplement.
	(cp_get_symbol_name_matcher): Return different matchers depending
	on the lookup name's match type.
	(selftests::test_cp_symbol_name_matches): Add wild matching tests.
	* cp-support.h (cp_search_name_hash): New declaration.
	* dwarf2read.c
	(selftests::dw2_expand_symtabs_matching::test_symbols): Add
	symbols.
	(test_dw2_expand_symtabs_matching_symbol): Add wild matching
	tests.
	* guile/scm-breakpoint.c (gdbscm_register_breakpoint_x): Adjust to
	pass a symbol_name_match_type to new_linespec_location.
	* linespec.c (linespec_parse_basic): Lookup function symbols using
	the parser's symbol name match type.
	(convert_explicit_location_to_linespec): New
	symbol_name_match_type parameter.  Pass it down to
	find_linespec_symbols.
	(convert_explicit_location_to_sals): Pass the location's name
	match type to convert_explicit_location_to_linespec.
	(parse_linespec): New match_type parameter.  Save it in the
	parser.
	(linespec_parser_new): Default to symbol_name_match_type::WILD.
	(linespec_complete_function): New symbol_name_match_type
	parameter.  Use it.
	(complete_linespec_component): Pass down the parser's recorded
	name match type.
	(linespec_complete_label): New symbol_name_match_type parameter.
	Use it.
	(linespec_complete): New symbol_name_match_type parameter.  Save
	it in the parser and pass it down.  Adjust to
	get_linespec_location's prototype change.
	(find_function_symbols, find_linespec_symbols): New
	symbol_name_match_type parameter.  Pass it down instead of
	assuming symbol_name_match_type::WILD.
	* linespec.h (linespec_complete, linespec_complete_function)
	(linespec_complete_label): New symbol_name_match_type parameter.
	* location.c (event_location::linespec_location): Now a struct
	linespec_location.
	(EL_LINESPEC): Adjust.
	(initialize_explicit_location): Default to
	symbol_name_match_type::WILD.
	(new_linespec_location): New symbol_name_match_type parameter.
	Record it in the location.
	(get_linespec_location): Now returns a struct linespec_location.
	(new_explicit_location): Also copy func_name_match_type.
	(explicit_to_string_internal)
	(string_to_explicit_location): Handle "-qualified".
	(copy_event_location): Adjust to LINESPEC_LOCATION type change.
	Copy symbol_name_match_type fields.
	(event_location_deleter::operator()): Adjust to LINESPEC_LOCATION
	type change.
	(event_location_to_string): Adjust to LINESPEC_LOCATION type
	change.  Handle "-qualfied".
	(string_to_explicit_location): Handle "-qualified".
	(string_to_event_location_basic): New symbol_name_match_type
	parameter.  Pass it down.
	(string_to_event_location): Handle "-qualified".
	* location.h (struct linespec_location): New.
	(explicit_location::func_name_match_type): New field.
	(new_linespec_location): Now returns a const linespec_location *.
	(string_to_event_location_basic): New symbol_name_match_type
	parameter.
	(explicit_completion_info::saw_explicit_location_option): New
	field.
	* mi/mi-cmd-break.c (mi_cmd_break_insert_1): Adjust to pass a
	symbol_name_match_type to new_linespec_location.
	* python/py-breakpoint.c (bppy_init): Likewise.
	* python/python.c (gdbpy_decode_line): Likewise.

gdb/testsuite/ChangeLog:
2017-11-29  Pedro Alves  <palves@redhat.com>

	* gdb.base/langs.exp: Use -qualified.
	* gdb.cp/meth-typedefs.exp: Use -qualified, and add tests without
	it.
	* gdb.cp/namespace.exp: Use -qualified.
	* gdb.linespec/cpcompletion.exp (overload-2, fqn, fqn-2)
	(overload-3, template-overload, template-ret-type, const-overload)
	(const-overload-quoted, anon-ns, ambiguous-prefix): New
	procedures.
	(test_driver): Call them.
	* gdb.cp/save-bp-qualified.cc: New.
	* gdb.cp/save-bp-qualified.exp: New.
	* gdb.linespec/explicit.exp: Test -qualified.
	* lib/completion-support.exp (completion::explicit_opts_list): Add
	"-qualified".
	* lib/gdb.exp (gdb_breakpoint): Handle "qualified".

gdb/doc/ChangeLog:
2017-11-29  Pedro Alves  <palves@redhat.com>

	* gdb.texinfo (Linespec Locations): Document how "function" is
	interpreted in C++ and Ada.  Document "-qualified".
	(Explicit Locations): Document how "-function" is interpreted in
	C++ and Ada.  Document "-qualified".
2017-11-29 19:43:48 +00:00

213 lines
7.5 KiB
C++

/* Header for GDB line completion.
Copyright (C) 2000-2017 Free Software Foundation, Inc.
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/>. */
#if !defined (LINESPEC_H)
#define LINESPEC_H 1
struct symtab;
#include "location.h"
#include "vec.h"
/* Flags to pass to decode_line_1 and decode_line_full. */
enum decode_line_flags
{
/* Set this flag if you want the resulting SALs to describe the
first line of indicated functions. */
DECODE_LINE_FUNFIRSTLINE = 1,
/* Set this flag if you want "list mode". In this mode, a
FILE:LINE linespec will always return a result, and such
linespecs will not be expanded to all matches. */
DECODE_LINE_LIST_MODE = 2
};
/* decode_line_full returns a vector of these. */
struct linespec_sals
{
/* This is the location corresponding to the sals contained in this
object. It can be passed as the FILTER argument to future calls
to decode_line_full. This is freed by the linespec_result
destructor. */
char *canonical;
/* Sals. */
std::vector<symtab_and_line> sals;
};
/* An instance of this may be filled in by decode_line_1. The caller
must make copies of any data that it needs to keep. */
struct linespec_result
{
linespec_result () = default;
~linespec_result ();
DISABLE_COPY_AND_ASSIGN (linespec_result);
/* If true, the linespec should be displayed to the user. This
is used by "unusual" linespecs where the ordinary `info break'
display mechanism would do the wrong thing. */
bool special_display = false;
/* If true, the linespec result should be considered to be a
"pre-expanded" multi-location linespec. A pre-expanded linespec
holds all matching locations in a single linespec_sals
object. */
bool pre_expanded = false;
/* If PRE_EXPANDED is non-zero, this is set to the location entered
by the user. */
event_location_up location;
/* The sals. The vector will be freed by the destructor. */
std::vector<linespec_sals> lsals;
};
/* Decode a linespec using the provided default symtab and line. */
extern std::vector<symtab_and_line>
decode_line_1 (const struct event_location *location, int flags,
struct program_space *search_pspace,
struct symtab *default_symtab, int default_line);
/* Parse LOCATION and return results. This is the "full"
interface to this module, which handles multiple results
properly.
For FLAGS, see decode_line_flags. DECODE_LINE_LIST_MODE is not
valid for this function.
If SEARCH_PSPACE is not NULL, symbol search is restricted to just
that program space.
DEFAULT_SYMTAB and DEFAULT_LINE describe the default location.
DEFAULT_SYMTAB can be NULL, in which case the current symtab and
line are used.
CANONICAL is where the results are stored. It must not be NULL.
SELECT_MODE must be one of the multiple_symbols_* constants, or
NULL. It determines how multiple results will be handled. If
NULL, the appropriate CLI value will be used.
FILTER can either be NULL or a string holding a canonical name.
This is only valid when SELECT_MODE is multiple_symbols_all.
Multiple results are handled differently depending on the
arguments:
. With multiple_symbols_cancel, an exception is thrown.
. With multiple_symbols_ask, a menu is presented to the user. The
user may select none, in which case an exception is thrown; or all,
which is handled like multiple_symbols_all, below. Otherwise,
CANONICAL->SALS will have one entry for each name the user chose.
. With multiple_symbols_all, CANONICAL->SALS will have a single
entry describing all the matching locations. If FILTER is
non-NULL, then only locations whose canonical name is equal (in the
strcmp sense) to FILTER will be returned; all others will be
filtered out. */
extern void decode_line_full (const struct event_location *location, int flags,
struct program_space *search_pspace,
struct symtab *default_symtab, int default_line,
struct linespec_result *canonical,
const char *select_mode,
const char *filter);
/* Given a string, return the line specified by it, using the current
source symtab and line as defaults.
This is for commands like "list" and "breakpoint". */
extern std::vector<symtab_and_line> decode_line_with_current_source
(const char *, int);
/* Given a string, return the line specified by it, using the last displayed
codepoint's values as defaults, or nothing if they aren't valid. */
extern std::vector<symtab_and_line> decode_line_with_last_displayed
(const char *, int);
/* Does P represent one of the keywords? If so, return
the keyword. If not, return NULL. */
extern const char *linespec_lexer_lex_keyword (const char *p);
/* Parse a line offset from STRING. */
extern struct line_offset linespec_parse_line_offset (const char *string);
/* Return the quote characters permitted by the linespec parser. */
extern const char *get_gdb_linespec_parser_quote_characters (void);
/* Does STRING represent an Ada operator? If so, return the length
of the decoded operator name. If not, return 0. */
extern int is_ada_operator (const char *string);
/* Find an instance of the character C in the string S that is outside
of all parenthesis pairs, single-quoted strings, and double-quoted
strings. Also, ignore the char within a template name, like a ','
within foo<int, int>. */
extern const char *find_toplevel_char (const char *s, char c);
/* Find the end of the (first) linespec pointed to by *STRINGP.
STRINGP will be advanced to this point. */
extern void linespec_lex_to_end (const char **stringp);
extern const char * const linespec_keywords[];
/* Complete a linespec. */
extern void linespec_complete (completion_tracker &tracker,
const char *text,
symbol_name_match_type match_type);
/* Complete a function symbol, in linespec mode, according to
FUNC_MATCH_TYPE. If SOURCE_FILENAME is non-NULL, limits completion
to the list of functions defined in source files that match
SOURCE_FILENAME. */
extern void linespec_complete_function (completion_tracker &tracker,
const char *function,
symbol_name_match_type func_match_type,
const char *source_filename);
/* Complete a label symbol, in linespec mode. Only labels of
functions named FUNCTION_NAME are considered. If SOURCE_FILENAME
is non-NULL, limits completion to labels of functions defined in
source files that match SOURCE_FILENAME. */
extern void linespec_complete_label (completion_tracker &tracker,
const struct language_defn *language,
const char *source_filename,
const char *function_name,
symbol_name_match_type name_match_type,
const char *label_name);
/* Evaluate the expression pointed to by EXP_PTR into a CORE_ADDR,
advancing EXP_PTR past any parsed text. */
extern CORE_ADDR linespec_expression_to_pc (const char **exp_ptr);
#endif /* defined (LINESPEC_H) */