binutils-gdb/gdb/location.c

941 lines
25 KiB
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/>. */
#include "defs.h"
#include "gdb_assert.h"
#include "location.h"
#include "symtab.h"
#include "language.h"
#include "linespec.h"
#include "cli/cli-utils.h"
#include "probe.h"
#include "cp-support.h"
#include <ctype.h>
#include <string.h>
/* An event location used to set a stop event in the inferior.
This structure is an amalgam of the various ways
to specify where a stop event should be set. */
struct event_location
{
/* The type of this breakpoint specification. */
enum event_location_type type;
#define EL_TYPE(P) (P)->type
union
{
/* A generic "this is a string specification" for a location.
This representation is used by both "normal" linespecs and
probes. */
char *addr_string;
#define EL_LINESPEC(P) ((P)->u.addr_string)
#define EL_PROBE(P) ((P)->u.addr_string)
/* An address in the inferior. */
CORE_ADDR address;
#define EL_ADDRESS(P) (P)->u.address
/* An explicit location. */
struct explicit_location explicit_loc;
#define EL_EXPLICIT(P) (&((P)->u.explicit_loc))
} u;
/* Cached string representation of this location. This is used, e.g., to
save stop event locations to file. Malloc'd. */
char *as_string;
#define EL_STRING(P) ((P)->as_string)
};
/* See description in location.h. */
enum event_location_type
event_location_type (const struct event_location *location)
{
return EL_TYPE (location);
}
/* See description in location.h. */
void
initialize_explicit_location (struct explicit_location *explicit_loc)
{
memset (explicit_loc, 0, sizeof (struct explicit_location));
explicit_loc->line_offset.sign = LINE_OFFSET_UNKNOWN;
}
/* See description in location.h. */
event_location_up
new_linespec_location (char **linespec)
{
struct event_location *location;
location = XCNEW (struct event_location);
EL_TYPE (location) = LINESPEC_LOCATION;
if (*linespec != NULL)
{
char *p;
char *orig = *linespec;
linespec_lex_to_end (linespec);
p = remove_trailing_whitespace (orig, *linespec);
if ((p - orig) > 0)
EL_LINESPEC (location) = savestring (orig, p - orig);
}
return event_location_up (location);
}
/* See description in location.h. */
const char *
get_linespec_location (const struct event_location *location)
{
gdb_assert (EL_TYPE (location) == LINESPEC_LOCATION);
return EL_LINESPEC (location);
}
/* See description in location.h. */
event_location_up
new_address_location (CORE_ADDR addr, const char *addr_string,
int addr_string_len)
{
struct event_location *location;
location = XCNEW (struct event_location);
EL_TYPE (location) = ADDRESS_LOCATION;
EL_ADDRESS (location) = addr;
if (addr_string != NULL)
EL_STRING (location) = xstrndup (addr_string, addr_string_len);
return event_location_up (location);
}
/* See description in location.h. */
CORE_ADDR
get_address_location (const struct event_location *location)
{
gdb_assert (EL_TYPE (location) == ADDRESS_LOCATION);
return EL_ADDRESS (location);
}
/* See description in location.h. */
const char *
get_address_string_location (const struct event_location *location)
{
gdb_assert (EL_TYPE (location) == ADDRESS_LOCATION);
return EL_STRING (location);
}
/* See description in location.h. */
event_location_up
new_probe_location (const char *probe)
{
struct event_location *location;
location = XCNEW (struct event_location);
EL_TYPE (location) = PROBE_LOCATION;
if (probe != NULL)
EL_PROBE (location) = xstrdup (probe);
return event_location_up (location);
}
/* See description in location.h. */
const char *
get_probe_location (const struct event_location *location)
{
gdb_assert (EL_TYPE (location) == PROBE_LOCATION);
return EL_PROBE (location);
}
/* See description in location.h. */
event_location_up
new_explicit_location (const struct explicit_location *explicit_loc)
{
struct event_location tmp;
memset (&tmp, 0, sizeof (struct event_location));
EL_TYPE (&tmp) = EXPLICIT_LOCATION;
initialize_explicit_location (EL_EXPLICIT (&tmp));
if (explicit_loc != NULL)
{
if (explicit_loc->source_filename != NULL)
{
EL_EXPLICIT (&tmp)->source_filename
= explicit_loc->source_filename;
}
if (explicit_loc->function_name != NULL)
EL_EXPLICIT (&tmp)->function_name
= explicit_loc->function_name;
if (explicit_loc->label_name != NULL)
EL_EXPLICIT (&tmp)->label_name = explicit_loc->label_name;
if (explicit_loc->line_offset.sign != LINE_OFFSET_UNKNOWN)
EL_EXPLICIT (&tmp)->line_offset = explicit_loc->line_offset;
}
return copy_event_location (&tmp);
}
/* See description in location.h. */
struct explicit_location *
get_explicit_location (struct event_location *location)
{
gdb_assert (EL_TYPE (location) == EXPLICIT_LOCATION);
return EL_EXPLICIT (location);
}
/* See description in location.h. */
const struct explicit_location *
get_explicit_location_const (const struct event_location *location)
{
gdb_assert (EL_TYPE (location) == EXPLICIT_LOCATION);
return EL_EXPLICIT (location);
}
/* This convenience function returns a malloc'd string which
represents the location in EXPLICIT_LOC.
AS_LINESPEC is non-zero if this string should be a linespec.
Otherwise it will be output in explicit form. */
static char *
explicit_to_string_internal (int as_linespec,
const struct explicit_location *explicit_loc)
{
int need_space = 0;
char space = as_linespec ? ':' : ' ';
string_file buf;
if (explicit_loc->source_filename != NULL)
{
if (!as_linespec)
buf.puts ("-source ");
buf.puts (explicit_loc->source_filename);
need_space = 1;
}
if (explicit_loc->function_name != NULL)
{
if (need_space)
buf.putc (space);
if (!as_linespec)
buf.puts ("-function ");
buf.puts (explicit_loc->function_name);
need_space = 1;
}
if (explicit_loc->label_name != NULL)
{
if (need_space)
buf.putc (space);
if (!as_linespec)
buf.puts ("-label ");
buf.puts (explicit_loc->label_name);
need_space = 1;
}
if (explicit_loc->line_offset.sign != LINE_OFFSET_UNKNOWN)
{
if (need_space)
buf.putc (space);
if (!as_linespec)
buf.puts ("-line ");
buf.printf ("%s%d",
(explicit_loc->line_offset.sign == LINE_OFFSET_NONE ? ""
: (explicit_loc->line_offset.sign
== LINE_OFFSET_PLUS ? "+" : "-")),
explicit_loc->line_offset.offset);
}
return xstrdup (buf.c_str ());
}
/* See description in location.h. */
char *
explicit_location_to_string (const struct explicit_location *explicit_loc)
{
return explicit_to_string_internal (0, explicit_loc);
}
/* See description in location.h. */
char *
explicit_location_to_linespec (const struct explicit_location *explicit_loc)
{
return explicit_to_string_internal (1, explicit_loc);
}
/* See description in location.h. */
event_location_up
copy_event_location (const struct event_location *src)
{
struct event_location *dst;
dst = XCNEW (struct event_location);
EL_TYPE (dst) = EL_TYPE (src);
if (EL_STRING (src) != NULL)
EL_STRING (dst) = xstrdup (EL_STRING (src));
switch (EL_TYPE (src))
{
case LINESPEC_LOCATION:
if (EL_LINESPEC (src) != NULL)
EL_LINESPEC (dst) = xstrdup (EL_LINESPEC (src));
break;
case ADDRESS_LOCATION:
EL_ADDRESS (dst) = EL_ADDRESS (src);
break;
case EXPLICIT_LOCATION:
if (EL_EXPLICIT (src)->source_filename != NULL)
EL_EXPLICIT (dst)->source_filename
= xstrdup (EL_EXPLICIT (src)->source_filename);
if (EL_EXPLICIT (src)->function_name != NULL)
EL_EXPLICIT (dst)->function_name
= xstrdup (EL_EXPLICIT (src)->function_name);
if (EL_EXPLICIT (src)->label_name != NULL)
EL_EXPLICIT (dst)->label_name = xstrdup (EL_EXPLICIT (src)->label_name);
EL_EXPLICIT (dst)->line_offset = EL_EXPLICIT (src)->line_offset;
break;
case PROBE_LOCATION:
if (EL_PROBE (src) != NULL)
EL_PROBE (dst) = xstrdup (EL_PROBE (src));
break;
default:
gdb_assert_not_reached ("unknown event location type");
}
return event_location_up (dst);
}
void
event_location_deleter::operator() (event_location *location) const
{
if (location != NULL)
{
xfree (EL_STRING (location));
switch (EL_TYPE (location))
{
case LINESPEC_LOCATION:
xfree (EL_LINESPEC (location));
break;
case ADDRESS_LOCATION:
/* Nothing to do. */
break;
case EXPLICIT_LOCATION:
xfree (EL_EXPLICIT (location)->source_filename);
xfree (EL_EXPLICIT (location)->function_name);
xfree (EL_EXPLICIT (location)->label_name);
break;
case PROBE_LOCATION:
xfree (EL_PROBE (location));
break;
default:
gdb_assert_not_reached ("unknown event location type");
}
xfree (location);
}
}
/* See description in location.h. */
const char *
event_location_to_string (struct event_location *location)
{
if (EL_STRING (location) == NULL)
{
switch (EL_TYPE (location))
{
case LINESPEC_LOCATION:
if (EL_LINESPEC (location) != NULL)
EL_STRING (location) = xstrdup (EL_LINESPEC (location));
break;
case ADDRESS_LOCATION:
EL_STRING (location)
= xstrprintf ("*%s",
core_addr_to_string (EL_ADDRESS (location)));
break;
case EXPLICIT_LOCATION:
EL_STRING (location)
= explicit_location_to_string (EL_EXPLICIT (location));
break;
case PROBE_LOCATION:
EL_STRING (location) = xstrdup (EL_PROBE (location));
break;
default:
gdb_assert_not_reached ("unknown event location type");
}
}
return EL_STRING (location);
}
/* Find an instance of the quote character C in the string S that is
outside of all single- and double-quoted strings (i.e., any quoting
other than C). */
static const char *
find_end_quote (const char *s, char end_quote_char)
{
/* zero if we're not in quotes;
'"' if we're in a double-quoted string;
'\'' if we're in a single-quoted string. */
char nested_quote_char = '\0';
for (const char *scan = s; *scan != '\0'; scan++)
{
if (nested_quote_char != '\0')
{
if (*scan == nested_quote_char)
nested_quote_char = '\0';
else if (scan[0] == '\\' && *(scan + 1) != '\0')
scan++;
}
else if (*scan == end_quote_char && nested_quote_char == '\0')
return scan;
else if (*scan == '"' || *scan == '\'')
nested_quote_char = *scan;
}
return 0;
}
/* A lexer for explicit locations. This function will advance INP
past any strings that it lexes. Returns a malloc'd copy of the
lexed string or NULL if no lexing was done. */
static gdb::unique_xmalloc_ptr<char>
explicit_location_lex_one (const char **inp,
const struct language_defn *language,
explicit_completion_info *completion_info)
{
const char *start = *inp;
if (*start == '\0')
return NULL;
/* If quoted, skip to the ending quote. */
if (strchr (get_gdb_linespec_parser_quote_characters (), *start))
{
if (completion_info != NULL)
completion_info->quoted_arg_start = start;
const char *end = find_end_quote (start + 1, *start);
if (end == NULL)
{
if (completion_info == NULL)
error (_("Unmatched quote, %s."), start);
end = start + strlen (start);
*inp = end;
return gdb::unique_xmalloc_ptr<char> (savestring (start + 1,
*inp - start - 1));
}
if (completion_info != NULL)
completion_info->quoted_arg_end = end;
*inp = end + 1;
return gdb::unique_xmalloc_ptr<char> (savestring (start + 1,
*inp - start - 2));
}
/* If the input starts with '-' or '+', the string ends with the next
whitespace or comma. */
if (*start == '-' || *start == '+')
{
while (*inp[0] != '\0' && *inp[0] != ',' && !isspace (*inp[0]))
++(*inp);
}
else
{
/* Handle numbers first, stopping at the next whitespace or ','. */
while (isdigit (*inp[0]))
++(*inp);
if (*inp[0] == '\0' || isspace (*inp[0]) || *inp[0] == ',')
return gdb::unique_xmalloc_ptr<char> (savestring (start,
*inp - start));
/* Otherwise stop at the next occurrence of whitespace, '\0',
keyword, or ','. */
*inp = start;
while ((*inp)[0]
&& (*inp)[0] != ','
&& !(isspace ((*inp)[0])
|| linespec_lexer_lex_keyword (&(*inp)[1])))
{
/* Special case: C++ operator,. */
if (language->la_language == language_cplus
&& startswith (*inp, CP_OPERATOR_STR))
(*inp) += CP_OPERATOR_LEN;
++(*inp);
}
}
if (*inp - start > 0)
return gdb::unique_xmalloc_ptr<char> (savestring (start, *inp - start));
return NULL;
}
/* Return true if COMMA points past "operator". START is the start of
the line that COMMAND points to, hence when reading backwards, we
must not read any character before START. */
static bool
is_cp_operator (const char *start, const char *comma)
{
if (comma != NULL
&& (comma - start) >= CP_OPERATOR_LEN)
{
const char *p = comma;
while (p > start && isspace (p[-1]))
p--;
if (p - start >= CP_OPERATOR_LEN)
{
p -= CP_OPERATOR_LEN;
if (strncmp (p, CP_OPERATOR_STR, CP_OPERATOR_LEN) == 0
&& (p == start
|| !(isalnum (p[-1]) || p[-1] == '_')))
{
return true;
}
}
}
return false;
}
/* When scanning the input string looking for the next explicit
location option/delimiter, we jump to the next option by looking
for ",", and "-". Such a character can also appear in C++ symbols
like "operator," and "operator-". So when we find such a
character, we call this function to check if we found such a
symbol, meaning we had a false positive for an option string. In
that case, we keep looking for the next delimiter, until we find
one that is not a false positive, or we reach end of string. FOUND
is the character that scanning found (either '-' or ','), and START
is the start of the line that FOUND points to, hence when reading
backwards, we must not read any character before START. Returns a
pointer to the next non-false-positive delimiter character, or NULL
if none was found. */
static const char *
skip_op_false_positives (const char *start, const char *found)
{
while (found != NULL && is_cp_operator (start, found))
{
if (found[0] == '-' && found[1] == '-')
start = found + 2;
else
start = found + 1;
found = find_toplevel_char (start, *found);
}
return found;
}
/* Assuming both FIRST and NEW_TOK point into the same string, return
the pointer that is closer to the start of the string. If FIRST is
NULL, returns NEW_TOK. If NEW_TOK is NULL, returns FIRST. */
static const char *
first_of (const char *first, const char *new_tok)
{
if (first == NULL)
return new_tok;
else if (new_tok != NULL && new_tok < first)
return new_tok;
else
return first;
}
/* A lexer for functions in explicit locations. This function will
advance INP past a function until the next option, or until end of
string. Returns a malloc'd copy of the lexed string or NULL if no
lexing was done. */
static gdb::unique_xmalloc_ptr<char>
explicit_location_lex_one_function (const char **inp,
const struct language_defn *language,
explicit_completion_info *completion_info)
{
const char *start = *inp;
if (*start == '\0')
return NULL;
/* If quoted, skip to the ending quote. */
if (strchr (get_gdb_linespec_parser_quote_characters (), *start))
{
char quote_char = *start;
/* If the input is not an Ada operator, skip to the matching
closing quote and return the string. */
if (!(language->la_language == language_ada
&& quote_char == '\"' && is_ada_operator (start)))
{
if (completion_info != NULL)
completion_info->quoted_arg_start = start;
const char *end = find_toplevel_char (start + 1, quote_char);
if (end == NULL)
{
if (completion_info == NULL)
error (_("Unmatched quote, %s."), start);
end = start + strlen (start);
*inp = end;
char *saved = savestring (start + 1, *inp - start - 1);
return gdb::unique_xmalloc_ptr<char> (saved);
}
if (completion_info != NULL)
completion_info->quoted_arg_end = end;
*inp = end + 1;
char *saved = savestring (start + 1, *inp - start - 2);
return gdb::unique_xmalloc_ptr<char> (saved);
}
}
const char *comma = find_toplevel_char (start, ',');
/* If we have "-function -myfunction", or perhaps better example,
"-function -[BasicClass doIt]" (objc selector), treat
"-myfunction" as the function name. I.e., skip the first char if
it is an hyphen. Don't skip the first char always, because we
may have C++ "operator<", and find_toplevel_char needs to see the
'o' in that case. */
const char *hyphen
= (*start == '-'
? find_toplevel_char (start + 1, '-')
: find_toplevel_char (start, '-'));
/* Check for C++ "operator," and "operator-". */
comma = skip_op_false_positives (start, comma);
hyphen = skip_op_false_positives (start, hyphen);
/* Pick the one that appears first. */
const char *end = first_of (hyphen, comma);
/* See if a linespec keyword appears first. */
const char *s = start;
const char *ws = find_toplevel_char (start, ' ');
while (ws != NULL && linespec_lexer_lex_keyword (ws + 1) == NULL)
{
s = ws + 1;
ws = find_toplevel_char (s, ' ');
}
if (ws != NULL)
end = first_of (end, ws + 1);
/* If we don't have any terminator, then take the whole string. */
if (end == NULL)
end = start + strlen (start);
/* Trim whitespace at the end. */
while (end > start && end[-1] == ' ')
end--;
*inp = end;
if (*inp - start > 0)
return gdb::unique_xmalloc_ptr<char> (savestring (start, *inp - start));
return NULL;
}
/* See description in location.h. */
event_location_up
string_to_explicit_location (const char **argp,
const struct language_defn *language,
explicit_completion_info *completion_info)
{
event_location_up location;
/* It is assumed that input beginning with '-' and a non-digit
character is an explicit location. "-p" is reserved, though,
for probe locations. */
if (argp == NULL
|| *argp == NULL
|| *argp[0] != '-'
|| !isalpha ((*argp)[1])
|| ((*argp)[0] == '-' && (*argp)[1] == 'p'))
return NULL;
location = new_explicit_location (NULL);
/* Process option/argument pairs. dprintf_command
requires that processing stop on ','. */
while ((*argp)[0] != '\0' && (*argp)[0] != ',')
{
int len;
const char *start;
/* Clear these on each iteration, since they should be filled
with info about the last option. */
if (completion_info != NULL)
{
completion_info->quoted_arg_start = NULL;
completion_info->quoted_arg_end = NULL;
}
/* If *ARGP starts with a keyword, stop processing
options. */
if (linespec_lexer_lex_keyword (*argp) != NULL)
break;
/* Mark the start of the string in case we need to rewind. */
start = *argp;
if (completion_info != NULL)
completion_info->last_option = start;
/* Get the option string. */
gdb::unique_xmalloc_ptr<char> opt
= explicit_location_lex_one (argp, language, NULL);
/* Use the length of the option to allow abbreviations. */
len = strlen (opt.get ());
/* Get the argument string. */
*argp = skip_spaces (*argp);
/* All options have a required argument. Checking for this
required argument is deferred until later. */
gdb::unique_xmalloc_ptr<char> oarg;
/* True if we have an argument. This is required because we'll
move from OARG before checking whether we have an
argument. */
bool have_oarg = false;
/* Convenience to consistently set both OARG/HAVE_OARG from
ARG. */
auto set_oarg = [&] (gdb::unique_xmalloc_ptr<char> arg)
{
oarg = std::move (arg);
have_oarg = oarg != NULL;
};
if (strncmp (opt.get (), "-source", len) == 0)
{
set_oarg (explicit_location_lex_one (argp, language,
completion_info));
EL_EXPLICIT (location)->source_filename = oarg.release ();
}
else if (strncmp (opt.get (), "-function", len) == 0)
{
set_oarg (explicit_location_lex_one_function (argp, language,
completion_info));
EL_EXPLICIT (location)->function_name = oarg.release ();
}
else if (strncmp (opt.get (), "-line", len) == 0)
{
set_oarg (explicit_location_lex_one (argp, language, NULL));
*argp = skip_spaces (*argp);
if (have_oarg)
{
EL_EXPLICIT (location)->line_offset
= linespec_parse_line_offset (oarg.get ());
continue;
}
}
else if (strncmp (opt.get (), "-label", len) == 0)
{
set_oarg (explicit_location_lex_one (argp, language, completion_info));
EL_EXPLICIT (location)->label_name = oarg.release ();
}
/* Only emit an "invalid argument" error for options
that look like option strings. */
else if (opt.get ()[0] == '-' && !isdigit (opt.get ()[1]))
{
if (completion_info == NULL)
error (_("invalid explicit location argument, \"%s\""), opt.get ());
}
else
{
/* End of the explicit location specification.
Stop parsing and return whatever explicit location was
parsed. */
*argp = start;
return location;
}
*argp = skip_spaces (*argp);
/* It's a little lame to error after the fact, but in this
case, it provides a much better user experience to issue
the "invalid argument" error before any missing
argument error. */
if (!have_oarg && completion_info == NULL)
error (_("missing argument for \"%s\""), opt.get ());
}
/* One special error check: If a source filename was given
without offset, function, or label, issue an error. */
if (EL_EXPLICIT (location)->source_filename != NULL
&& EL_EXPLICIT (location)->function_name == NULL
&& EL_EXPLICIT (location)->label_name == NULL
&& (EL_EXPLICIT (location)->line_offset.sign == LINE_OFFSET_UNKNOWN)
&& completion_info == NULL)
{
error (_("Source filename requires function, label, or "
"line offset."));
}
return location;
}
/* See description in location.h. */
event_location_up
string_to_event_location_basic (char **stringp,
const struct language_defn *language)
{
event_location_up location;
const char *cs;
/* Try the input as a probe spec. */
cs = *stringp;
if (cs != NULL && probe_linespec_to_ops (&cs) != NULL)
{
location = new_probe_location (*stringp);
*stringp += strlen (*stringp);
}
else
{
/* Try an address location. */
if (*stringp != NULL && **stringp == '*')
{
const char *arg, *orig;
CORE_ADDR addr;
orig = arg = *stringp;
addr = linespec_expression_to_pc (&arg);
location = new_address_location (addr, orig, arg - orig);
*stringp += arg - orig;
}
else
{
/* Everything else is a linespec. */
location = new_linespec_location (stringp);
}
}
return location;
}
/* See description in location.h. */
event_location_up
string_to_event_location (char **stringp,
const struct language_defn *language)
{
const char *arg, *orig;
/* Try an explicit location. */
orig = arg = *stringp;
event_location_up location = string_to_explicit_location (&arg, language, NULL);
if (location != NULL)
{
/* It was a valid explicit location. Advance STRINGP to
the end of input. */
*stringp += arg - orig;
}
else
{
/* Everything else is a "basic" linespec, address, or probe
location. */
location = string_to_event_location_basic (stringp, language);
}
return location;
}
/* See description in location.h. */
int
event_location_empty_p (const struct event_location *location)
{
switch (EL_TYPE (location))
{
case LINESPEC_LOCATION:
/* Linespecs are never "empty." (NULL is a valid linespec) */
return 0;
case ADDRESS_LOCATION:
return 0;
case EXPLICIT_LOCATION:
return (EL_EXPLICIT (location) == NULL
|| (EL_EXPLICIT (location)->source_filename == NULL
&& EL_EXPLICIT (location)->function_name == NULL
&& EL_EXPLICIT (location)->label_name == NULL
&& (EL_EXPLICIT (location)->line_offset.sign
== LINE_OFFSET_UNKNOWN)));
case PROBE_LOCATION:
return EL_PROBE (location) == NULL;
default:
gdb_assert_not_reached ("unknown event location type");
}
}
/* See description in location.h. */
void
set_event_location_string (struct event_location *location,
const char *string)
{
xfree (EL_STRING (location));
EL_STRING (location) = string == NULL ? NULL : xstrdup (string);
}