binutils-gdb/gdb/location.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

286 lines
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C++

/* Data structures and API for event locations in GDB.
Copyright (C) 2013-2017 Free Software Foundation, 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 LOCATIONS_H
#define LOCATIONS_H 1
struct language_defn;
struct event_location;
/* An enumeration of possible signs for a line offset. */
enum offset_relative_sign
{
/* No sign */
LINE_OFFSET_NONE,
/* A plus sign ("+") */
LINE_OFFSET_PLUS,
/* A minus sign ("-") */
LINE_OFFSET_MINUS,
/* A special "sign" for unspecified offset. */
LINE_OFFSET_UNKNOWN
};
/* A line offset in a location. */
struct line_offset
{
/* Line offset and any specified sign. */
int offset;
enum offset_relative_sign sign;
};
/* An enumeration of the various ways to specify a stop event
location (used with create_breakpoint). */
enum event_location_type
{
/* A traditional linespec. */
LINESPEC_LOCATION,
/* An address in the inferior. */
ADDRESS_LOCATION,
/* An explicit location. */
EXPLICIT_LOCATION,
/* A probe location. */
PROBE_LOCATION
};
/* A traditional linespec. */
struct linespec_location
{
/* Whether the function name is fully-qualified or not. */
symbol_name_match_type match_type;
/* The linespec. */
char *spec_string;
};
/* An explicit location. This structure is used to bypass the
parsing done on linespecs. It still has the same requirements
as linespecs, though. For example, source_filename requires
at least one other field. */
struct explicit_location
{
/* The source filename. Malloc'd. */
char *source_filename;
/* The function name. Malloc'd. */
char *function_name;
/* Whether the function name is fully-qualified or not. */
symbol_name_match_type func_name_match_type;
/* The name of a label. Malloc'd. */
char *label_name;
/* A line offset relative to the start of the symbol
identified by the above fields or the current symtab
if the other fields are NULL. */
struct line_offset line_offset;
};
/* Return the type of the given event location. */
extern enum event_location_type
event_location_type (const struct event_location *);
/* Return a malloc'd explicit string representation of the given
explicit location. The location must already be canonicalized/valid. */
extern char *
explicit_location_to_string (const struct explicit_location *explicit_loc);
/* Return a malloc'd linespec string representation of the given
explicit location. The location must already be canonicalized/valid. */
extern char *
explicit_location_to_linespec (const struct explicit_location *explicit_loc);
/* Return a string representation of the LOCATION.
This function may return NULL for unspecified linespecs,
e.g, LINESPEC_LOCATION and spec_string is NULL.
The result is cached in LOCATION. */
extern const char *
event_location_to_string (struct event_location *location);
/* A deleter for a struct event_location. */
struct event_location_deleter
{
void operator() (event_location *location) const;
};
/* A unique pointer for event_location. */
typedef std::unique_ptr<event_location, event_location_deleter>
event_location_up;
/* Create a new linespec location. */
extern event_location_up new_linespec_location
(const char **linespec, symbol_name_match_type match_type);
/* Return the linespec location of the given event_location (which
must be of type LINESPEC_LOCATION). */
extern const linespec_location *
get_linespec_location (const struct event_location *location);
/* Create a new address location.
ADDR is the address corresponding to this event_location.
ADDR_STRING, a string of ADDR_STRING_LEN characters, is
the expression that was parsed to determine the address ADDR. */
extern event_location_up new_address_location (CORE_ADDR addr,
const char *addr_string,
int addr_string_len);
/* Return the address location (a CORE_ADDR) of the given event_location
(which must be of type ADDRESS_LOCATION). */
extern CORE_ADDR
get_address_location (const struct event_location *location);
/* Return the expression (a string) that was used to compute the address
of the given event_location (which must be of type ADDRESS_LOCATION). */
extern const char *
get_address_string_location (const struct event_location *location);
/* Create a new probe location. */
extern event_location_up new_probe_location (const char *probe);
/* Return the probe location (a string) of the given event_location
(which must be of type PROBE_LOCATION). */
extern const char *
get_probe_location (const struct event_location *location);
/* Initialize the given explicit location. */
extern void
initialize_explicit_location (struct explicit_location *explicit_loc);
/* Create a new explicit location. If not NULL, EXPLICIT is checked for
validity. If invalid, an exception is thrown. */
extern event_location_up
new_explicit_location (const struct explicit_location *explicit_loc);
/* Return the explicit location of the given event_location
(which must be of type EXPLICIT_LOCATION). */
extern struct explicit_location *
get_explicit_location (struct event_location *location);
/* A const version of the above. */
extern const struct explicit_location *
get_explicit_location_const (const struct event_location *location);
/* Return a copy of the given SRC location. */
extern event_location_up
copy_event_location (const struct event_location *src);
/* Attempt to convert the input string in *ARGP into an event_location.
ARGP is advanced past any processed input. Returns an event_location
(malloc'd) if an event location was successfully found in *ARGP,
NULL otherwise.
This function may call error() if *ARGP looks like properly formed,
but invalid, input, e.g., if it is called with missing argument parameters
or invalid options.
This function is intended to be used by CLI commands and will parse
explicit locations in a CLI-centric way. Other interfaces should use
string_to_event_location_basic if they want to maintain support for
legacy specifications of probe, address, and linespec locations. */
extern event_location_up
string_to_event_location (const char **argp,
const struct language_defn *langauge);
/* Like string_to_event_location, but does not attempt to parse
explicit locations. MATCH_TYPE indicates how function names should
be matched. */
extern event_location_up
string_to_event_location_basic (const char **argp,
const struct language_defn *language,
symbol_name_match_type match_type);
/* Structure filled in by string_to_explicit_location to aid the
completer. */
struct explicit_completion_info
{
/* Pointer to the last option found. E.g., in "b -sou src.c -fun
func", LAST_OPTION is left pointing at "-fun func". */
const char *last_option = NULL;
/* These point to the start and end of a quoted argument, iff the
last argument was quoted. If parsing finds an incomplete quoted
string (e.g., "break -function 'fun"), then QUOTED_ARG_START is
set to point to the opening \', and QUOTED_ARG_END is left NULL.
If the last option is not quoted, then both are set to NULL. */
const char *quoted_arg_start = NULL;
const char *quoted_arg_end = NULL;
/* True if we saw an explicit location option, as opposed to only
flags that affect both explicit locations and linespecs, like
"-qualified". */
bool saw_explicit_location_option = false;
};
/* Attempt to convert the input string in *ARGP into an explicit location.
ARGP is advanced past any processed input. Returns an event_location
(malloc'd) if an explicit location was successfully found in *ARGP,
NULL otherwise.
If COMPLETION_INFO is NULL, this function may call error() if *ARGP
looks like improperly formed input, e.g., if it is called with
missing argument parameters or invalid options. If COMPLETION_INFO
is not NULL, this function will not throw any exceptions. */
extern event_location_up
string_to_explicit_location (const char **argp,
const struct language_defn *language,
explicit_completion_info *completion_info);
/* A convenience function for testing for unset locations. */
extern int event_location_empty_p (const struct event_location *location);
/* Set the location's string representation. If STRING is NULL, clear
the string representation. */
extern void
set_event_location_string (struct event_location *location,
const char *string);
#endif /* LOCATIONS_H */