old-cross-binutils/gdb/cp-support.c
David Carlton 0f20eeea6c 2003-04-23 David Carlton <carlton@bactrian.org>
* cp-support.c (cp_find_first_component): Accept 'operator' in
	more locations.

2003-04-23  David Carlton  <carlton@bactrian.org>

	* gdb.c++/maint.exp (test_first_component): Add tests for
	'operator' in more locations.
2003-04-23 23:45:24 +00:00

364 lines
9.9 KiB
C

/* Helper routines for C++ support in GDB.
Copyright 2002, 2003 Free Software Foundation, Inc.
Contributed by MontaVista Software.
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 2 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, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include "defs.h"
#include <ctype.h>
#include "cp-support.h"
#include "gdb_string.h"
#include "demangle.h"
#include "gdb_assert.h"
#include "gdbcmd.h"
/* The list of "maint cplus" commands. */
static struct cmd_list_element *maint_cplus_cmd_list = NULL;
/* The actual commands. */
static void maint_cplus_command (char *arg, int from_tty);
static void first_component_command (char *arg, int from_tty);
/* Here are some random pieces of trivia to keep in mind while trying
to take apart demangled names:
- Names can contain function arguments or templates, so the process
has to be, to some extent recursive: maybe keep track of your
depth based on encountering <> and ().
- Parentheses don't just have to happen at the end of a name: they
can occur even if the name in question isn't a function, because
a template argument might be a type that's a function.
- Conversely, even if you're trying to deal with a function, its
demangled name might not end with ')': it could be a const or
volatile class method, in which case it ends with "const" or
"volatile".
- Parentheses are also used in anonymous namespaces: a variable
'foo' in an anonymous namespace gets demangled as "(anonymous
namespace)::foo".
- And operator names can contain parentheses or angle brackets. */
/* FIXME: carlton/2003-03-13: We have several functions here with
overlapping functionality; can we combine them? Also, do they
handle all the above considerations correctly? */
/* Find the last component of the demangled C++ name NAME. NAME
must be a method name including arguments, in order to correctly
locate the last component.
This function return a pointer to the first colon before the
last component, or NULL if the name had only one component. */
static const char *
find_last_component (const char *name)
{
const char *p;
int depth;
/* Functions can have local classes, so we need to find the
beginning of the last argument list, not the end of the first
one. */
p = name + strlen (name) - 1;
while (p > name && *p != ')')
p--;
if (p == name)
return NULL;
/* P now points at the `)' at the end of the argument list. Walk
back to the beginning. */
p--;
depth = 1;
while (p > name && depth > 0)
{
if (*p == '<' || *p == '(')
depth--;
else if (*p == '>' || *p == ')')
depth++;
p--;
}
if (p == name)
return NULL;
while (p > name && *p != ':')
p--;
if (p == name || p == name + 1 || p[-1] != ':')
return NULL;
return p - 1;
}
/* Return the name of the class containing method PHYSNAME. */
char *
class_name_from_physname (const char *physname)
{
char *ret = NULL;
const char *end;
int depth = 0;
char *demangled_name = cplus_demangle (physname, DMGL_ANSI);
if (demangled_name == NULL)
return NULL;
end = find_last_component (demangled_name);
if (end != NULL)
{
ret = xmalloc (end - demangled_name + 1);
memcpy (ret, demangled_name, end - demangled_name);
ret[end - demangled_name] = '\0';
}
xfree (demangled_name);
return ret;
}
/* Return the name of the method whose linkage name is PHYSNAME. */
char *
method_name_from_physname (const char *physname)
{
char *ret = NULL;
const char *end;
int depth = 0;
char *demangled_name = cplus_demangle (physname, DMGL_ANSI);
if (demangled_name == NULL)
return NULL;
end = find_last_component (demangled_name);
if (end != NULL)
{
char *args;
int len;
/* Skip "::". */
end = end + 2;
/* Find the argument list, if any. */
args = strchr (end, '(');
if (args == NULL)
len = strlen (end + 2);
else
{
args --;
while (*args == ' ')
args --;
len = args - end + 1;
}
ret = xmalloc (len + 1);
memcpy (ret, end, len);
ret[len] = 0;
}
xfree (demangled_name);
return ret;
}
/* This returns the length of first component of NAME, which should be
the demangled name of a C++ variable/function/method/etc.
Specifically, it returns the index of the first colon forming the
boundary of the first component: so, given 'A::foo' or 'A::B::foo'
it returns the 1, and given 'foo', it returns 0. */
/* Well, that's what it should do when called externally, but to make
the recursion easier, it also stops if it reaches an unexpected ')'
or '>'. */
/* NOTE: carlton/2003-03-13: This function is currently only intended
for internal use: it's probably not entirely safe when called on
user-generated input, because some of the 'index += 2' lines might
go past the end of malformed input. */
/* Let's optimize away calls to strlen("operator"). */
#define LENGTH_OF_OPERATOR 8
unsigned int
cp_find_first_component (const char *name)
{
unsigned int index = 0;
/* Operator names can show up in unexpected places. Since these can
contain parentheses or angle brackets, they can screw up the
recursion. But not every string 'operator' is part of an
operater name: e.g. you could have a variable 'cooperator'. So
this variable tells us whether or not we should treat the string
'operator' as starting an operator. */
int operator_possible = 1;
for (;; ++index)
{
switch (name[index])
{
case '<':
/* Template; eat it up. The calls to cp_first_component
should only return (I hope!) when they reach the '>'
terminating the component or a '::' between two
components. (Hence the '+ 2'.) */
index += 1;
for (index += cp_find_first_component (name + index);
name[index] != '>';
index += cp_find_first_component (name + index))
{
gdb_assert (name[index] == ':');
index += 2;
}
operator_possible = 1;
break;
case '(':
/* Similar comment as to '<'. */
index += 1;
for (index += cp_find_first_component (name + index);
name[index] != ')';
index += cp_find_first_component (name + index))
{
gdb_assert (name[index] == ':');
index += 2;
}
operator_possible = 1;
break;
case '>':
case ')':
case '\0':
case ':':
return index;
case 'o':
/* Operator names can screw up the recursion. */
if (operator_possible
&& strncmp (name + index, "operator", LENGTH_OF_OPERATOR) == 0)
{
index += LENGTH_OF_OPERATOR;
while (isspace(name[index]))
++index;
switch (name[index])
{
/* Skip over one less than the appropriate number of
characters: the for loop will skip over the last
one. */
case '<':
if (name[index + 1] == '<')
index += 1;
else
index += 0;
break;
case '>':
case '-':
if (name[index + 1] == '>')
index += 1;
else
index += 0;
break;
case '(':
index += 1;
break;
default:
index += 0;
break;
}
}
operator_possible = 0;
break;
case ' ':
case ',':
case '.':
case '&':
case '*':
/* NOTE: carlton/2003-04-18: I'm not sure what the precise
set of relevant characters are here: it's necessary to
include any character that can show up before 'operator'
in a demangled name, and it's safe to include any
character that can't be part of an identifier's name. */
operator_possible = 1;
break;
default:
operator_possible = 0;
break;
}
}
}
/* If NAME is the fully-qualified name of a C++
function/variable/method/etc., this returns the length of its
entire prefix: all of the namespaces and classes that make up its
name. Given 'A::foo', it returns 1, given 'A::B::foo', it returns
4, given 'foo', it returns 0. */
unsigned int
cp_entire_prefix_len (const char *name)
{
unsigned int current_len = cp_find_first_component (name);
unsigned int previous_len = 0;
while (name[current_len] != '\0')
{
gdb_assert (name[current_len] == ':');
previous_len = current_len;
/* Skip the '::'. */
current_len += 2;
current_len += cp_find_first_component (name + current_len);
}
return previous_len;
}
/* Don't allow just "maintenance cplus". */
static void
maint_cplus_command (char *arg, int from_tty)
{
printf_unfiltered ("\"maintenance cplus\" must be followed by the name of a command.\n");
help_list (maint_cplus_cmd_list, "maintenance cplus ", -1, gdb_stdout);
}
/* This is a front end for cp_find_first_component, for unit testing.
Be careful when using it: see the NOTE above
cp_find_first_component. */
static void
first_component_command (char *arg, int from_tty)
{
int len = cp_find_first_component (arg);
char *prefix = alloca (len + 1);
memcpy (prefix, arg, len);
prefix[len] = '\0';
printf_unfiltered ("%s\n", prefix);
}
void
_initialize_cp_support (void)
{
add_prefix_cmd ("cplus", class_maintenance, maint_cplus_command,
"C++ maintenance commands.", &maint_cplus_cmd_list,
"maintenance cplus ", 0, &maintenancelist);
add_alias_cmd ("cp", "cplus", class_maintenance, 1, &maintenancelist);
add_cmd ("first_component", class_maintenance, first_component_command,
"Print the first class/namespace component of NAME.",
&maint_cplus_cmd_list);
}