/* Abstraction of GNU v2 abi. Contributed by Daniel Berlin <dberlin@redhat.com> Copyright 2001 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 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 "gdb_string.h" #include "symtab.h" #include "gdbtypes.h" #include "value.h" #include "demangle.h" #include "cp-abi.h" #include <ctype.h> struct cp_abi_ops gnu_v2_abi_ops; static int vb_match (struct type *, int, struct type *); static enum dtor_kinds gnuv2_is_destructor_name (const char *name) { if ((name[0] == '_' && is_cplus_marker (name[1]) && name[2] == '_') || strncmp (name, "__dt__", 6) == 0) return complete_object_dtor; else return 0; } static enum ctor_kinds gnuv2_is_constructor_name (const char *name) { if ((name[0] == '_' && name[1] == '_' && (isdigit (name[2]) || strchr ("Qt", name[2]))) || strncmp (name, "__ct__", 6) == 0) return complete_object_ctor; else return 0; } static int gnuv2_is_vtable_name (const char *name) { return (((name)[0] == '_' && (((name)[1] == 'V' && (name)[2] == 'T') || ((name)[1] == 'v' && (name)[2] == 't')) && is_cplus_marker ((name)[3])) || ((name)[0] == '_' && (name)[1] == '_' && (name)[2] == 'v' && (name)[3] == 't' && (name)[4] == '_')); } static int gnuv2_is_operator_name (const char *name) { return strncmp (name, "operator", 8) == 0; } /* Return a virtual function as a value. ARG1 is the object which provides the virtual function table pointer. *ARG1P is side-effected in calling this function. F is the list of member functions which contains the desired virtual function. J is an index into F which provides the desired virtual function. TYPE is the type in which F is located. */ static value_ptr gnuv2_virtual_fn_field (value_ptr * arg1p, struct fn_field * f, int j, struct type * type, int offset) { value_ptr arg1 = *arg1p; struct type *type1 = check_typedef (VALUE_TYPE (arg1)); struct type *entry_type; /* First, get the virtual function table pointer. That comes with a strange type, so cast it to type `pointer to long' (which should serve just fine as a function type). Then, index into the table, and convert final value to appropriate function type. */ value_ptr entry, vfn, vtbl; value_ptr vi = value_from_longest (builtin_type_int, (LONGEST) TYPE_FN_FIELD_VOFFSET (f, j)); struct type *fcontext = TYPE_FN_FIELD_FCONTEXT (f, j); struct type *context; if (fcontext == NULL) /* We don't have an fcontext (e.g. the program was compiled with g++ version 1). Try to get the vtbl from the TYPE_VPTR_BASETYPE. This won't work right for multiple inheritance, but at least we should do as well as GDB 3.x did. */ fcontext = TYPE_VPTR_BASETYPE (type); context = lookup_pointer_type (fcontext); /* Now context is a pointer to the basetype containing the vtbl. */ if (TYPE_TARGET_TYPE (context) != type1) { value_ptr tmp = value_cast (context, value_addr (arg1)); arg1 = value_ind (tmp); type1 = check_typedef (VALUE_TYPE (arg1)); } context = type1; /* Now context is the basetype containing the vtbl. */ /* This type may have been defined before its virtual function table was. If so, fill in the virtual function table entry for the type now. */ if (TYPE_VPTR_FIELDNO (context) < 0) fill_in_vptr_fieldno (context); /* The virtual function table is now an array of structures which have the form { int16 offset, delta; void *pfn; }. */ vtbl = value_primitive_field (arg1, 0, TYPE_VPTR_FIELDNO (context), TYPE_VPTR_BASETYPE (context)); /* With older versions of g++, the vtbl field pointed to an array of structures. Nowadays it points directly to the structure. */ if (TYPE_CODE (VALUE_TYPE (vtbl)) == TYPE_CODE_PTR && TYPE_CODE (TYPE_TARGET_TYPE (VALUE_TYPE (vtbl))) == TYPE_CODE_ARRAY) { /* Handle the case where the vtbl field points to an array of structures. */ vtbl = value_ind (vtbl); /* Index into the virtual function table. This is hard-coded because looking up a field is not cheap, and it may be important to save time, e.g. if the user has set a conditional breakpoint calling a virtual function. */ entry = value_subscript (vtbl, vi); } else { /* Handle the case where the vtbl field points directly to a structure. */ vtbl = value_add (vtbl, vi); entry = value_ind (vtbl); } entry_type = check_typedef (VALUE_TYPE (entry)); if (TYPE_CODE (entry_type) == TYPE_CODE_STRUCT) { /* Move the `this' pointer according to the virtual function table. */ VALUE_OFFSET (arg1) += value_as_long (value_field (entry, 0)); if (!VALUE_LAZY (arg1)) { VALUE_LAZY (arg1) = 1; value_fetch_lazy (arg1); } vfn = value_field (entry, 2); } else if (TYPE_CODE (entry_type) == TYPE_CODE_PTR) vfn = entry; else error ("I'm confused: virtual function table has bad type"); /* Reinstantiate the function pointer with the correct type. */ VALUE_TYPE (vfn) = lookup_pointer_type (TYPE_FN_FIELD_TYPE (f, j)); *arg1p = arg1; return vfn; } struct type * gnuv2_value_rtti_type (value_ptr v, int *full, int *top, int *using_enc) { struct type *known_type; struct type *rtti_type; CORE_ADDR coreptr; value_ptr vp; int using_enclosing = 0; long top_offset = 0; char rtti_type_name[256]; CORE_ADDR vtbl; struct minimal_symbol *minsym; struct symbol *sym; char *demangled_name; struct type *btype; if (full) *full = 0; if (top) *top = -1; if (using_enc) *using_enc = 0; /* Get declared type */ known_type = VALUE_TYPE (v); CHECK_TYPEDEF (known_type); /* RTTI works only or class objects */ if (TYPE_CODE (known_type) != TYPE_CODE_CLASS) return NULL; /* Plan on this changing in the future as i get around to setting the vtables properly for G++ compiled stuff. Also, I'll be using the type info functions, which are always right. Deal with it until then. */ /* If the type has no vptr fieldno, try to get it filled in */ if (TYPE_VPTR_FIELDNO(known_type) < 0) fill_in_vptr_fieldno(known_type); /* If we still can't find one, give up */ if (TYPE_VPTR_FIELDNO(known_type) < 0) return NULL; /* Make sure our basetype and known type match, otherwise, cast so we can get at the vtable properly. */ btype = TYPE_VPTR_BASETYPE (known_type); CHECK_TYPEDEF (btype); if (btype != known_type ) { v = value_cast (btype, v); if (using_enc) *using_enc=1; } /* We can't use value_ind here, because it would want to use RTTI, and we'd waste a bunch of time figuring out we already know the type. Besides, we don't care about the type, just the actual pointer */ if (VALUE_ADDRESS (value_field (v, TYPE_VPTR_FIELDNO (known_type))) == 0) return NULL; /* If we are enclosed by something that isn't us, adjust the address properly and set using_enclosing. */ if (VALUE_ENCLOSING_TYPE(v) != VALUE_TYPE(v)) { value_ptr tempval; int bitpos = TYPE_BASECLASS_BITPOS (known_type, TYPE_VPTR_FIELDNO (known_type)); tempval=value_field (v, TYPE_VPTR_FIELDNO(known_type)); VALUE_ADDRESS(tempval) += bitpos / 8; vtbl=value_as_pointer (tempval); using_enclosing=1; } else { vtbl=value_as_pointer(value_field(v,TYPE_VPTR_FIELDNO(known_type))); using_enclosing=0; } /* Try to find a symbol that is the vtable */ minsym=lookup_minimal_symbol_by_pc(vtbl); if (minsym==NULL || (demangled_name=SYMBOL_NAME(minsym))==NULL || !is_vtable_name (demangled_name)) return NULL; /* If we just skip the prefix, we get screwed by namespaces */ demangled_name=cplus_demangle(demangled_name,DMGL_PARAMS|DMGL_ANSI); *(strchr(demangled_name,' '))=0; /* Lookup the type for the name */ rtti_type=lookup_typename(demangled_name, (struct block *)0,1); if (rtti_type==NULL) return NULL; if (TYPE_N_BASECLASSES(rtti_type) > 1 && full && (*full) != 1) { if (top) *top=TYPE_BASECLASS_BITPOS(rtti_type,TYPE_VPTR_FIELDNO(rtti_type))/8; if (top && ((*top) >0)) { if (TYPE_LENGTH(rtti_type) > TYPE_LENGTH(known_type)) { if (full) *full=0; } else { if (full) *full=1; } } } else { if (full) *full=1; } if (using_enc) *using_enc=using_enclosing; return rtti_type; } static void init_gnuv2_ops (void) { gnu_v2_abi_ops.shortname = "gnu-v2"; gnu_v2_abi_ops.longname = "GNU G++ Version 2 ABI"; gnu_v2_abi_ops.doc = "G++ Version 2 ABI"; gnu_v2_abi_ops.is_destructor_name = gnuv2_is_destructor_name; gnu_v2_abi_ops.is_constructor_name = gnuv2_is_constructor_name; gnu_v2_abi_ops.is_vtable_name = gnuv2_is_vtable_name; gnu_v2_abi_ops.is_operator_name = gnuv2_is_operator_name; gnu_v2_abi_ops.virtual_fn_field = gnuv2_virtual_fn_field; gnu_v2_abi_ops.rtti_type = gnuv2_value_rtti_type; } void _initialize_gnu_v2_abi (void) { init_gnuv2_ops (); register_cp_abi (gnu_v2_abi_ops); switch_to_cp_abi ("gnu-v2"); }