X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=gdb%2Fgnu-v3-abi.c;h=3a52df3c4080d06fb489c2f42a3dca18e2ab1e6c;hb=2bd7c093f663139ad9e57ddc748ade12f6bfbe01;hp=a4c79605000cd8bf3a5fd50759ace436af913960;hpb=98081e55d97de9b28768be80794d3f117ac4dd1e;p=deliverable%2Fbinutils-gdb.git diff --git a/gdb/gnu-v3-abi.c b/gdb/gnu-v3-abi.c index a4c7960500..3a52df3c40 100644 --- a/gdb/gnu-v3-abi.c +++ b/gdb/gnu-v3-abi.c @@ -1,13 +1,15 @@ /* Abstraction of GNU v3 abi. Contributed by Jim Blandy - Copyright 2001 Free Software Foundation, Inc. + + Copyright (C) 2001, 2002, 2003, 2005, 2006, 2007, 2008, 2009 + 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 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 @@ -15,15 +17,18 @@ 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. */ + along with this program. If not, see . */ #include "defs.h" #include "value.h" #include "cp-abi.h" +#include "cp-support.h" #include "demangle.h" +#include "objfiles.h" +#include "valprint.h" + #include "gdb_assert.h" +#include "gdb_string.h" static struct cp_abi_ops gnu_v3_abi_ops; @@ -40,6 +45,21 @@ gnuv3_is_operator_name (const char *name) } +/* Determine architecture of class DOMAIN. This architecture is used + to query C++ ABI details (types, method pointer layout, etc.). + + Note that we assume DOMAIN must have been allocated with an OBJFILE; + GDB does not provide any built-in class types. Thus we use the + architecture of that OBJFILE to define the C++ ABI. */ + +static struct gdbarch * +get_class_arch (struct type *domain) +{ + gdb_assert (TYPE_CODE (domain) == TYPE_CODE_CLASS); + gdb_assert (TYPE_OBJFILE (domain) != NULL); + return get_objfile_arch (TYPE_OBJFILE (domain)); +} + /* To help us find the components of a vtable, we build ourselves a GDB type object representing the vtable structure. Following the V3 ABI, it goes something like this: @@ -93,9 +113,7 @@ enum { described above, laid out appropriately for ARCH. We use this function as the gdbarch per-architecture data - initialization function. We assume that the gdbarch framework - calls the per-architecture data initialization functions after it - sets current_gdbarch to the new architecture. */ + initialization function. */ static void * build_gdb_vtable_type (struct gdbarch *arch) { @@ -104,13 +122,14 @@ build_gdb_vtable_type (struct gdbarch *arch) int offset; struct type *void_ptr_type - = lookup_pointer_type (builtin_type_void); + = builtin_type (arch)->builtin_data_ptr; struct type *ptr_to_void_fn_type - = lookup_pointer_type (lookup_function_type (builtin_type_void)); + = builtin_type (arch)->builtin_func_ptr; /* ARCH can't give us the true ptrdiff_t type, so we guess. */ struct type *ptrdiff_type - = init_type (TYPE_CODE_INT, TARGET_PTR_BIT / TARGET_CHAR_BIT, 0, + = init_type (TYPE_CODE_INT, + gdbarch_ptr_bit (arch) / TARGET_CHAR_BIT, 0, "ptrdiff_t", 0); /* We assume no padding is necessary, since GDB doesn't know @@ -128,7 +147,7 @@ build_gdb_vtable_type (struct gdbarch *arch) FIELD_NAME (*field) = "vcall_and_vbase_offsets"; FIELD_TYPE (*field) = create_array_type (0, ptrdiff_type, - create_range_type (0, builtin_type_int, 0, -1)); + create_range_type (0, builtin_type_int32, 0, -1)); FIELD_BITPOS (*field) = offset * TARGET_CHAR_BIT; offset += TYPE_LENGTH (FIELD_TYPE (*field)); field++; @@ -151,7 +170,7 @@ build_gdb_vtable_type (struct gdbarch *arch) FIELD_NAME (*field) = "virtual_functions"; FIELD_TYPE (*field) = create_array_type (0, ptr_to_void_fn_type, - create_range_type (0, builtin_type_int, 0, -1)); + create_range_type (0, builtin_type_int32, 0, -1)); FIELD_BITPOS (*field) = offset * TARGET_CHAR_BIT; offset += TYPE_LENGTH (FIELD_TYPE (*field)); field++; @@ -168,13 +187,23 @@ build_gdb_vtable_type (struct gdbarch *arch) } +/* Return the ptrdiff_t type used in the vtable type. */ +static struct type * +vtable_ptrdiff_type (struct gdbarch *gdbarch) +{ + struct type *vtable_type = gdbarch_data (gdbarch, vtable_type_gdbarch_data); + + /* The "offset_to_top" field has the appropriate (ptrdiff_t) type. */ + return TYPE_FIELD_TYPE (vtable_type, vtable_field_offset_to_top); +} + /* Return the offset from the start of the imaginary `struct gdb_gnu_v3_abi_vtable' object to the vtable's "address point" (i.e., where objects' virtual table pointers point). */ static int -vtable_address_point_offset () +vtable_address_point_offset (struct gdbarch *gdbarch) { - struct type *vtable_type = gdbarch_data (vtable_type_gdbarch_data); + struct type *vtable_type = gdbarch_data (gdbarch, vtable_type_gdbarch_data); return (TYPE_FIELD_BITPOS (vtable_type, vtable_field_virtual_functions) / TARGET_CHAR_BIT); @@ -185,26 +214,39 @@ static struct type * gnuv3_rtti_type (struct value *value, int *full_p, int *top_p, int *using_enc_p) { - struct type *vtable_type = gdbarch_data (vtable_type_gdbarch_data); - struct type *value_type = check_typedef (VALUE_TYPE (value)); + struct gdbarch *gdbarch; + struct type *vtable_type; + struct type *values_type = check_typedef (value_type (value)); CORE_ADDR vtable_address; struct value *vtable; struct minimal_symbol *vtable_symbol; const char *vtable_symbol_name; const char *class_name; - struct symbol *class_symbol; struct type *run_time_type; struct type *base_type; LONGEST offset_to_top; + struct type *values_type_vptr_basetype; + int values_type_vptr_fieldno; /* We only have RTTI for class objects. */ - if (TYPE_CODE (value_type) != TYPE_CODE_CLASS) + if (TYPE_CODE (values_type) != TYPE_CODE_CLASS) return NULL; - /* If we can't find the virtual table pointer for value_type, we + /* This routine may be called for Java types that do not have + a proper objfile. Just return NULL for those. */ + if (!TYPE_OBJFILE (values_type) + || !TYPE_OBJFILE (values_type)->obfd) + return NULL; + + /* Determine architecture. */ + gdbarch = get_class_arch (values_type); + vtable_type = gdbarch_data (gdbarch, vtable_type_gdbarch_data); + + /* If we can't find the virtual table pointer for values_type, we can't find the RTTI. */ - fill_in_vptr_fieldno (value_type); - if (TYPE_VPTR_FIELDNO (value_type) == -1) + values_type_vptr_fieldno = get_vptr_fieldno (values_type, + &values_type_vptr_basetype); + if (values_type_vptr_fieldno == -1) return NULL; if (using_enc_p) @@ -212,24 +254,24 @@ gnuv3_rtti_type (struct value *value, /* Fetch VALUE's virtual table pointer, and tweak it to point at an instance of our imaginary gdb_gnu_v3_abi_vtable structure. */ - base_type = check_typedef (TYPE_VPTR_BASETYPE (value_type)); - if (value_type != base_type) + base_type = check_typedef (values_type_vptr_basetype); + if (values_type != base_type) { value = value_cast (base_type, value); if (using_enc_p) *using_enc_p = 1; } vtable_address - = value_as_address (value_field (value, TYPE_VPTR_FIELDNO (value_type))); - vtable = value_at_lazy (vtable_type, - vtable_address - vtable_address_point_offset (), - VALUE_BFD_SECTION (value)); + = value_as_address (value_field (value, values_type_vptr_fieldno)); + vtable + = value_at_lazy (vtable_type, + vtable_address - vtable_address_point_offset (gdbarch)); /* Find the linker symbol for this vtable. */ vtable_symbol = lookup_minimal_symbol_by_pc (VALUE_ADDRESS (vtable) - + VALUE_OFFSET (vtable) - + VALUE_EMBEDDED_OFFSET (vtable)); + + value_offset (vtable) + + value_embedded_offset (vtable)); if (! vtable_symbol) return NULL; @@ -241,25 +283,20 @@ gnuv3_rtti_type (struct value *value, vtable_symbol_name = SYMBOL_DEMANGLED_NAME (vtable_symbol); if (vtable_symbol_name == NULL || strncmp (vtable_symbol_name, "vtable for ", 11)) - error ("can't find linker symbol for virtual table for `%s' value", - TYPE_NAME (value_type)); + { + warning (_("can't find linker symbol for virtual table for `%s' value"), + TYPE_NAME (values_type)); + if (vtable_symbol_name) + warning (_(" found `%s' instead"), vtable_symbol_name); + return NULL; + } class_name = vtable_symbol_name + 11; /* Try to look up the class name as a type name. */ - class_symbol = lookup_symbol (class_name, 0, STRUCT_NAMESPACE, 0, 0); - if (! class_symbol) - error ("can't find class named `%s', as given by C++ RTTI", class_name); - - /* Make sure the type symbol is sane. (An earlier version of this - code would find constructor functions, who have the same name as - the class.) */ - if (SYMBOL_CLASS (class_symbol) != LOC_TYPEDEF - || TYPE_CODE (SYMBOL_TYPE (class_symbol)) != TYPE_CODE_CLASS) - error ("C++ RTTI gives a class name of `%s', but that isn't a type name", - class_name); - - /* This is the object's run-time type! */ - run_time_type = SYMBOL_TYPE (class_symbol); + /* FIXME: chastain/2003-11-26: block=NULL is bogus. See pr gdb/1465. */ + run_time_type = cp_lookup_rtti_type (class_name, NULL); + if (run_time_type == NULL) + return NULL; /* Get the offset from VALUE to the top of the complete object. NOTE: this is the reverse of the meaning of *TOP_P. */ @@ -267,8 +304,8 @@ gnuv3_rtti_type (struct value *value, = value_as_long (value_field (vtable, vtable_field_offset_to_top)); if (full_p) - *full_p = (- offset_to_top == VALUE_EMBEDDED_OFFSET (value) - && (TYPE_LENGTH (VALUE_ENCLOSING_TYPE (value)) + *full_p = (- offset_to_top == value_embedded_offset (value) + && (TYPE_LENGTH (value_enclosing_type (value)) >= TYPE_LENGTH (run_time_type))); if (top_p) *top_p = - offset_to_top; @@ -276,70 +313,97 @@ gnuv3_rtti_type (struct value *value, return run_time_type; } +/* Find the vtable for CONTAINER and return a value of the correct + vtable type for this architecture. */ static struct value * -gnuv3_virtual_fn_field (struct value **value_p, - struct fn_field *f, int j, - struct type *type, int offset) +gnuv3_get_vtable (struct gdbarch *gdbarch, struct value *container) { - struct type *vtable_type = gdbarch_data (vtable_type_gdbarch_data); - struct value *value = *value_p; - struct type *value_type = check_typedef (VALUE_TYPE (value)); - struct type *vfn_base; - CORE_ADDR vtable_address; - struct value *vtable; - struct value *vfn; + struct type *vtable_type = gdbarch_data (gdbarch, vtable_type_gdbarch_data); + struct type *vtable_pointer_type; + struct value *vtable_pointer; + CORE_ADDR vtable_pointer_address, vtable_address; + + /* We do not consult the debug information to find the virtual table. + The ABI specifies that it is always at offset zero in any class, + and debug information may not represent it. We won't issue an + error if there's a class with virtual functions but no virtual table + pointer, but something's already gone seriously wrong if that + happens. + + We avoid using value_contents on principle, because the object might + be large. */ + + /* Find the type "pointer to virtual table". */ + vtable_pointer_type = lookup_pointer_type (vtable_type); + + /* Load it from the start of the class. */ + vtable_pointer_address = value_as_address (value_addr (container)); + vtable_pointer = value_at (vtable_pointer_type, vtable_pointer_address); + vtable_address = value_as_address (vtable_pointer); + + /* Correct it to point at the start of the virtual table, rather + than the address point. */ + return value_at_lazy (vtable_type, + vtable_address - vtable_address_point_offset (gdbarch)); +} - /* Some simple sanity checks. */ - if (TYPE_CODE (value_type) != TYPE_CODE_CLASS) - error ("Only classes can have virtual functions."); - - /* Find the base class that defines this virtual function. */ - vfn_base = TYPE_FN_FIELD_FCONTEXT (f, j); - if (! vfn_base) - /* In programs compiled with G++ version 1, the debug info doesn't - say which base class defined the virtual function. We'll guess - it's the same base class that has our vtable; this is wrong for - multiple inheritance, but it's better than nothing. */ - vfn_base = TYPE_VPTR_BASETYPE (type); - - /* 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 (vfn_base) < 0) - fill_in_vptr_fieldno (vfn_base); - - /* Now that we know which base class is defining our virtual - function, cast our value to that baseclass. This takes care of - any necessary `this' adjustments. */ - if (vfn_base != value_type) - value = value_cast (vfn_base, value); - - /* Now value is an object of the appropriate base type. Fetch its - virtual table. */ - /* It might be possible to do this cast at the same time as the above. - Does multiple inheritance affect this? */ - if (TYPE_VPTR_BASETYPE (vfn_base) != vfn_base) - value = value_cast (TYPE_VPTR_BASETYPE (vfn_base), value); - vtable_address - = value_as_address (value_field (value, TYPE_VPTR_FIELDNO (vfn_base))); +/* Return a function pointer for CONTAINER's VTABLE_INDEX'th virtual + function, of type FNTYPE. */ - vtable = value_at_lazy (vtable_type, - vtable_address - vtable_address_point_offset (), - VALUE_BFD_SECTION (value)); +static struct value * +gnuv3_get_virtual_fn (struct gdbarch *gdbarch, struct value *container, + struct type *fntype, int vtable_index) +{ + struct value *vtable = gnuv3_get_vtable (gdbarch, container); + struct value *vfn; /* Fetch the appropriate function pointer from the vtable. */ vfn = value_subscript (value_field (vtable, vtable_field_virtual_functions), - value_from_longest (builtin_type_int, - TYPE_FN_FIELD_VOFFSET (f, j))); + value_from_longest (builtin_type_int32, vtable_index)); + + /* If this architecture uses function descriptors directly in the vtable, + then the address of the vtable entry is actually a "function pointer" + (i.e. points to the descriptor). We don't need to scale the index + by the size of a function descriptor; GCC does that before outputing + debug information. */ + if (gdbarch_vtable_function_descriptors (gdbarch)) + vfn = value_addr (vfn); /* Cast the function pointer to the appropriate type. */ - vfn = value_cast (lookup_pointer_type (TYPE_FN_FIELD_TYPE (f, j)), - vfn); + vfn = value_cast (lookup_pointer_type (fntype), vfn); return vfn; } +/* GNU v3 implementation of value_virtual_fn_field. See cp-abi.h + for a description of the arguments. */ + +static struct value * +gnuv3_virtual_fn_field (struct value **value_p, + struct fn_field *f, int j, + struct type *vfn_base, int offset) +{ + struct type *values_type = check_typedef (value_type (*value_p)); + struct gdbarch *gdbarch; + + /* Some simple sanity checks. */ + if (TYPE_CODE (values_type) != TYPE_CODE_CLASS) + error (_("Only classes can have virtual functions.")); + + /* Determine architecture. */ + gdbarch = get_class_arch (values_type); + + /* Cast our value to the base class which defines this virtual + function. This takes care of any necessary `this' + adjustments. */ + if (vfn_base != values_type) + *value_p = value_cast (vfn_base, *value_p); + + return gnuv3_get_virtual_fn (gdbarch, *value_p, TYPE_FN_FIELD_TYPE (f, j), + TYPE_FN_FIELD_VOFFSET (f, j)); +} + /* Compute the offset of the baseclass which is the INDEXth baseclass of class TYPE, for value at VALADDR (in host) at ADDRESS (in target). @@ -347,20 +411,24 @@ gnuv3_virtual_fn_field (struct value **value_p, to (the address of)(ARG) + OFFSET. -1 is returned on error. */ -int -gnuv3_baseclass_offset (struct type *type, int index, char *valaddr, +static int +gnuv3_baseclass_offset (struct type *type, int index, const bfd_byte *valaddr, CORE_ADDR address) { - struct type *vtable_type = gdbarch_data (vtable_type_gdbarch_data); - struct type *basetype = TYPE_BASECLASS (type, index); - struct value *full_object, *vbase_object, *orig_object; - struct value *vtable, *orig_typeinfo, *orig_base_info; - struct type *orig_type, *vbasetype; + struct gdbarch *gdbarch; + struct type *vtable_type; + struct type *ptr_type; + struct value *vtable; + struct type *vbasetype; struct value *offset_val, *vbase_array; CORE_ADDR vtable_address; long int cur_base_offset, base_offset; - int to_top; - int baseclasses, i; + int vbasetype_vptr_fieldno; + + /* Determine architecture. */ + gdbarch = get_class_arch (type); + vtable_type = gdbarch_data (gdbarch, vtable_type_gdbarch_data); + ptr_type = builtin_type (gdbarch)->builtin_data_ptr; /* If it isn't a virtual base, this is easy. The offset is in the type definition. */ @@ -373,56 +441,460 @@ gnuv3_baseclass_offset (struct type *type, int index, char *valaddr, complete inheritance graph based on the debug info. Neither is worthwhile. */ cur_base_offset = TYPE_BASECLASS_BITPOS (type, index) / 8; - if (cur_base_offset >= - vtable_address_point_offset ()) - error ("Expected a negative vbase offset (old compiler?)"); + if (cur_base_offset >= - vtable_address_point_offset (gdbarch)) + error (_("Expected a negative vbase offset (old compiler?)")); - cur_base_offset = cur_base_offset + vtable_address_point_offset (); - if ((- cur_base_offset) % TYPE_LENGTH (builtin_type_void_data_ptr) != 0) - error ("Misaligned vbase offset."); - cur_base_offset = cur_base_offset - / ((int) TYPE_LENGTH (builtin_type_void_data_ptr)); + cur_base_offset = cur_base_offset + vtable_address_point_offset (gdbarch); + if ((- cur_base_offset) % TYPE_LENGTH (ptr_type) != 0) + error (_("Misaligned vbase offset.")); + cur_base_offset = cur_base_offset / ((int) TYPE_LENGTH (ptr_type)); /* We're now looking for the cur_base_offset'th entry (negative index) - in the vcall_and_vbase_offsets array. */ - - orig_object = value_at_lazy (type, address, NULL); - vbasetype = TYPE_VPTR_BASETYPE (VALUE_TYPE (orig_object)); - vbase_object = value_cast (vbasetype, orig_object); - - vtable_address - = value_as_address (value_field (vbase_object, - TYPE_VPTR_FIELDNO (vbasetype))); - vtable = value_at_lazy (vtable_type, - vtable_address - vtable_address_point_offset (), - NULL); - offset_val = value_from_longest(builtin_type_int, cur_base_offset); + in the vcall_and_vbase_offsets array. We used to cast the object to + its TYPE_VPTR_BASETYPE, and reference the vtable as TYPE_VPTR_FIELDNO; + however, that cast can not be done without calling baseclass_offset again + if the TYPE_VPTR_BASETYPE is a virtual base class, as described in the + v3 C++ ABI Section 2.4.I.2.b. Fortunately the ABI guarantees that the + vtable pointer will be located at the beginning of the object, so we can + bypass the casting. Verify that the TYPE_VPTR_FIELDNO is in fact at the + start of whichever baseclass it resides in, as a sanity measure - iff + we have debugging information for that baseclass. */ + + vbasetype = check_typedef (TYPE_VPTR_BASETYPE (type)); + vbasetype_vptr_fieldno = get_vptr_fieldno (vbasetype, NULL); + + if (vbasetype_vptr_fieldno >= 0 + && TYPE_FIELD_BITPOS (vbasetype, vbasetype_vptr_fieldno) != 0) + error (_("Illegal vptr offset in class %s"), + TYPE_NAME (vbasetype) ? TYPE_NAME (vbasetype) : ""); + + vtable_address = value_as_address (value_at_lazy (ptr_type, address)); + vtable + = value_at_lazy (vtable_type, + vtable_address - vtable_address_point_offset (gdbarch)); + offset_val = value_from_longest (builtin_type_int32, cur_base_offset); vbase_array = value_field (vtable, vtable_field_vcall_and_vbase_offsets); base_offset = value_as_long (value_subscript (vbase_array, offset_val)); return base_offset; } +/* Locate a virtual method in DOMAIN or its non-virtual base classes + which has virtual table index VOFFSET. The method has an associated + "this" adjustment of ADJUSTMENT bytes. */ + +static const char * +gnuv3_find_method_in (struct type *domain, CORE_ADDR voffset, + LONGEST adjustment) +{ + int i; + const char *physname; + + /* Search this class first. */ + physname = NULL; + if (adjustment == 0) + { + int len; + + len = TYPE_NFN_FIELDS (domain); + for (i = 0; i < len; i++) + { + int len2, j; + struct fn_field *f; + + f = TYPE_FN_FIELDLIST1 (domain, i); + len2 = TYPE_FN_FIELDLIST_LENGTH (domain, i); + + check_stub_method_group (domain, i); + for (j = 0; j < len2; j++) + if (TYPE_FN_FIELD_VOFFSET (f, j) == voffset) + return TYPE_FN_FIELD_PHYSNAME (f, j); + } + } + + /* Next search non-virtual bases. If it's in a virtual base, + we're out of luck. */ + for (i = 0; i < TYPE_N_BASECLASSES (domain); i++) + { + int pos; + struct type *basetype; + + if (BASETYPE_VIA_VIRTUAL (domain, i)) + continue; + + pos = TYPE_BASECLASS_BITPOS (domain, i) / 8; + basetype = TYPE_FIELD_TYPE (domain, i); + /* Recurse with a modified adjustment. We don't need to adjust + voffset. */ + if (adjustment >= pos && adjustment < pos + TYPE_LENGTH (basetype)) + return gnuv3_find_method_in (basetype, voffset, adjustment - pos); + } + + return NULL; +} + +/* Decode GNU v3 method pointer. */ + +static int +gnuv3_decode_method_ptr (struct gdbarch *gdbarch, + const gdb_byte *contents, + CORE_ADDR *value_p, + LONGEST *adjustment_p) +{ + struct type *funcptr_type = builtin_type (gdbarch)->builtin_func_ptr; + struct type *offset_type = vtable_ptrdiff_type (gdbarch); + CORE_ADDR ptr_value; + LONGEST voffset, adjustment; + int vbit; + + /* Extract the pointer to member. The first element is either a pointer + or a vtable offset. For pointers, we need to use extract_typed_address + to allow the back-end to convert the pointer to a GDB address -- but + vtable offsets we must handle as integers. At this point, we do not + yet know which case we have, so we extract the value under both + interpretations and choose the right one later on. */ + ptr_value = extract_typed_address (contents, funcptr_type); + voffset = extract_signed_integer (contents, TYPE_LENGTH (funcptr_type)); + contents += TYPE_LENGTH (funcptr_type); + adjustment = extract_signed_integer (contents, TYPE_LENGTH (offset_type)); + + if (!gdbarch_vbit_in_delta (gdbarch)) + { + vbit = voffset & 1; + voffset = voffset ^ vbit; + } + else + { + vbit = adjustment & 1; + adjustment = adjustment >> 1; + } + + *value_p = vbit? voffset : ptr_value; + *adjustment_p = adjustment; + return vbit; +} + +/* GNU v3 implementation of cplus_print_method_ptr. */ + +static void +gnuv3_print_method_ptr (const gdb_byte *contents, + struct type *type, + struct ui_file *stream) +{ + struct type *domain = TYPE_DOMAIN_TYPE (type); + struct gdbarch *gdbarch = get_class_arch (domain); + CORE_ADDR ptr_value; + LONGEST adjustment; + int vbit; + + /* Extract the pointer to member. */ + vbit = gnuv3_decode_method_ptr (gdbarch, contents, &ptr_value, &adjustment); + + /* Check for NULL. */ + if (ptr_value == 0 && vbit == 0) + { + fprintf_filtered (stream, "NULL"); + return; + } + + /* Search for a virtual method. */ + if (vbit) + { + CORE_ADDR voffset; + const char *physname; + + /* It's a virtual table offset, maybe in this class. Search + for a field with the correct vtable offset. First convert it + to an index, as used in TYPE_FN_FIELD_VOFFSET. */ + voffset = ptr_value / TYPE_LENGTH (vtable_ptrdiff_type (gdbarch)); + + physname = gnuv3_find_method_in (domain, voffset, adjustment); + + /* If we found a method, print that. We don't bother to disambiguate + possible paths to the method based on the adjustment. */ + if (physname) + { + char *demangled_name = cplus_demangle (physname, + DMGL_ANSI | DMGL_PARAMS); + if (demangled_name != NULL) + { + fprintf_filtered (stream, "&virtual "); + fputs_filtered (demangled_name, stream); + xfree (demangled_name); + return; + } + } + } + + /* We didn't find it; print the raw data. */ + if (vbit) + { + fprintf_filtered (stream, "&virtual table offset "); + print_longest (stream, 'd', 1, ptr_value); + } + else + print_address_demangle (ptr_value, stream, demangle); + + if (adjustment) + { + fprintf_filtered (stream, ", this adjustment "); + print_longest (stream, 'd', 1, adjustment); + } +} + +/* GNU v3 implementation of cplus_method_ptr_size. */ + +static int +gnuv3_method_ptr_size (struct type *type) +{ + struct type *domain_type = check_typedef (TYPE_DOMAIN_TYPE (type)); + struct gdbarch *gdbarch = get_class_arch (domain_type); + return 2 * TYPE_LENGTH (builtin_type (gdbarch)->builtin_data_ptr); +} + +/* GNU v3 implementation of cplus_make_method_ptr. */ + +static void +gnuv3_make_method_ptr (struct type *type, gdb_byte *contents, + CORE_ADDR value, int is_virtual) +{ + struct type *domain_type = check_typedef (TYPE_DOMAIN_TYPE (type)); + struct gdbarch *gdbarch = get_class_arch (domain_type); + int size = TYPE_LENGTH (builtin_type (gdbarch)->builtin_data_ptr); + + /* FIXME drow/2006-12-24: The adjustment of "this" is currently + always zero, since the method pointer is of the correct type. + But if the method pointer came from a base class, this is + incorrect - it should be the offset to the base. The best + fix might be to create the pointer to member pointing at the + base class and cast it to the derived class, but that requires + support for adjusting pointers to members when casting them - + not currently supported by GDB. */ + + if (!gdbarch_vbit_in_delta (gdbarch)) + { + store_unsigned_integer (contents, size, value | is_virtual); + store_unsigned_integer (contents + size, size, 0); + } + else + { + store_unsigned_integer (contents, size, value); + store_unsigned_integer (contents + size, size, is_virtual); + } +} + +/* GNU v3 implementation of cplus_method_ptr_to_value. */ + +static struct value * +gnuv3_method_ptr_to_value (struct value **this_p, struct value *method_ptr) +{ + struct gdbarch *gdbarch; + const gdb_byte *contents = value_contents (method_ptr); + CORE_ADDR ptr_value; + struct type *domain_type, *final_type, *method_type; + LONGEST adjustment; + struct value *adjval; + int vbit; + + domain_type = TYPE_DOMAIN_TYPE (check_typedef (value_type (method_ptr))); + final_type = lookup_pointer_type (domain_type); + + method_type = TYPE_TARGET_TYPE (check_typedef (value_type (method_ptr))); + + /* Extract the pointer to member. */ + gdbarch = get_class_arch (domain_type); + vbit = gnuv3_decode_method_ptr (gdbarch, contents, &ptr_value, &adjustment); + + /* First convert THIS to match the containing type of the pointer to + member. This cast may adjust the value of THIS. */ + *this_p = value_cast (final_type, *this_p); + + /* Then apply whatever adjustment is necessary. This creates a somewhat + strange pointer: it claims to have type FINAL_TYPE, but in fact it + might not be a valid FINAL_TYPE. For instance, it might be a + base class of FINAL_TYPE. And if it's not the primary base class, + then printing it out as a FINAL_TYPE object would produce some pretty + garbage. + + But we don't really know the type of the first argument in + METHOD_TYPE either, which is why this happens. We can't + dereference this later as a FINAL_TYPE, but once we arrive in the + called method we'll have debugging information for the type of + "this" - and that'll match the value we produce here. + + You can provoke this case by casting a Base::* to a Derived::*, for + instance. */ + *this_p = value_cast (builtin_type (gdbarch)->builtin_data_ptr, *this_p); + adjval = value_from_longest (builtin_type (gdbarch)->builtin_long, + adjustment); + *this_p = value_ptradd (*this_p, adjval); + *this_p = value_cast (final_type, *this_p); + + if (vbit) + { + LONGEST voffset; + voffset = ptr_value / TYPE_LENGTH (vtable_ptrdiff_type (gdbarch)); + return gnuv3_get_virtual_fn (gdbarch, value_ind (*this_p), + method_type, voffset); + } + else + return value_from_pointer (lookup_pointer_type (method_type), ptr_value); +} + +/* Determine if we are currently in a C++ thunk. If so, get the address + of the routine we are thunking to and continue to there instead. */ + +static CORE_ADDR +gnuv3_skip_trampoline (struct frame_info *frame, CORE_ADDR stop_pc) +{ + CORE_ADDR real_stop_pc, method_stop_pc; + struct gdbarch *gdbarch = get_frame_arch (frame); + struct minimal_symbol *thunk_sym, *fn_sym; + struct obj_section *section; + char *thunk_name, *fn_name; + + real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc); + if (real_stop_pc == 0) + real_stop_pc = stop_pc; + + /* Find the linker symbol for this potential thunk. */ + thunk_sym = lookup_minimal_symbol_by_pc (real_stop_pc); + section = find_pc_section (real_stop_pc); + if (thunk_sym == NULL || section == NULL) + return 0; + + /* The symbol's demangled name should be something like "virtual + thunk to FUNCTION", where FUNCTION is the name of the function + being thunked to. */ + thunk_name = SYMBOL_DEMANGLED_NAME (thunk_sym); + if (thunk_name == NULL || strstr (thunk_name, " thunk to ") == NULL) + return 0; + + fn_name = strstr (thunk_name, " thunk to ") + strlen (" thunk to "); + fn_sym = lookup_minimal_symbol (fn_name, NULL, section->objfile); + if (fn_sym == NULL) + return 0; + + method_stop_pc = SYMBOL_VALUE_ADDRESS (fn_sym); + real_stop_pc = gdbarch_skip_trampoline_code + (gdbarch, frame, method_stop_pc); + if (real_stop_pc == 0) + real_stop_pc = method_stop_pc; + + return real_stop_pc; +} + +/* Return nonzero if a type should be passed by reference. + + The rule in the v3 ABI document comes from section 3.1.1. If the + type has a non-trivial copy constructor or destructor, then the + caller must make a copy (by calling the copy constructor if there + is one or perform the copy itself otherwise), pass the address of + the copy, and then destroy the temporary (if necessary). + + For return values with non-trivial copy constructors or + destructors, space will be allocated in the caller, and a pointer + will be passed as the first argument (preceding "this"). + + We don't have a bulletproof mechanism for determining whether a + constructor or destructor is trivial. For GCC and DWARF2 debug + information, we can check the artificial flag. + + We don't do anything with the constructors or destructors, + but we have to get the argument passing right anyway. */ +static int +gnuv3_pass_by_reference (struct type *type) +{ + int fieldnum, fieldelem; + + CHECK_TYPEDEF (type); + + /* We're only interested in things that can have methods. */ + if (TYPE_CODE (type) != TYPE_CODE_STRUCT + && TYPE_CODE (type) != TYPE_CODE_CLASS + && TYPE_CODE (type) != TYPE_CODE_UNION) + return 0; + + for (fieldnum = 0; fieldnum < TYPE_NFN_FIELDS (type); fieldnum++) + for (fieldelem = 0; fieldelem < TYPE_FN_FIELDLIST_LENGTH (type, fieldnum); + fieldelem++) + { + struct fn_field *fn = TYPE_FN_FIELDLIST1 (type, fieldnum); + char *name = TYPE_FN_FIELDLIST_NAME (type, fieldnum); + struct type *fieldtype = TYPE_FN_FIELD_TYPE (fn, fieldelem); + + /* If this function is marked as artificial, it is compiler-generated, + and we assume it is trivial. */ + if (TYPE_FN_FIELD_ARTIFICIAL (fn, fieldelem)) + continue; + + /* If we've found a destructor, we must pass this by reference. */ + if (name[0] == '~') + return 1; + + /* If the mangled name of this method doesn't indicate that it + is a constructor, we're not interested. + + FIXME drow/2007-09-23: We could do this using the name of + the method and the name of the class instead of dealing + with the mangled name. We don't have a convenient function + to strip off both leading scope qualifiers and trailing + template arguments yet. */ + if (!is_constructor_name (TYPE_FN_FIELD_PHYSNAME (fn, fieldelem))) + continue; + + /* If this method takes two arguments, and the second argument is + a reference to this class, then it is a copy constructor. */ + if (TYPE_NFIELDS (fieldtype) == 2 + && TYPE_CODE (TYPE_FIELD_TYPE (fieldtype, 1)) == TYPE_CODE_REF + && check_typedef (TYPE_TARGET_TYPE (TYPE_FIELD_TYPE (fieldtype, 1))) == type) + return 1; + } + + /* Even if all the constructors and destructors were artificial, one + of them may have invoked a non-artificial constructor or + destructor in a base class. If any base class needs to be passed + by reference, so does this class. Similarly for members, which + are constructed whenever this class is. We do not need to worry + about recursive loops here, since we are only looking at members + of complete class type. */ + for (fieldnum = 0; fieldnum < TYPE_NFIELDS (type); fieldnum++) + if (gnuv3_pass_by_reference (TYPE_FIELD_TYPE (type, fieldnum))) + return 1; + + return 0; +} + static void init_gnuv3_ops (void) { - vtable_type_gdbarch_data = register_gdbarch_data (build_gdb_vtable_type, 0); + vtable_type_gdbarch_data = gdbarch_data_register_post_init (build_gdb_vtable_type); gnu_v3_abi_ops.shortname = "gnu-v3"; gnu_v3_abi_ops.longname = "GNU G++ Version 3 ABI"; gnu_v3_abi_ops.doc = "G++ Version 3 ABI"; - gnu_v3_abi_ops.is_destructor_name = is_gnu_v3_mangled_dtor; - gnu_v3_abi_ops.is_constructor_name = is_gnu_v3_mangled_ctor; + gnu_v3_abi_ops.is_destructor_name = + (enum dtor_kinds (*) (const char *))is_gnu_v3_mangled_dtor; + gnu_v3_abi_ops.is_constructor_name = + (enum ctor_kinds (*) (const char *))is_gnu_v3_mangled_ctor; gnu_v3_abi_ops.is_vtable_name = gnuv3_is_vtable_name; gnu_v3_abi_ops.is_operator_name = gnuv3_is_operator_name; gnu_v3_abi_ops.rtti_type = gnuv3_rtti_type; gnu_v3_abi_ops.virtual_fn_field = gnuv3_virtual_fn_field; gnu_v3_abi_ops.baseclass_offset = gnuv3_baseclass_offset; + gnu_v3_abi_ops.print_method_ptr = gnuv3_print_method_ptr; + gnu_v3_abi_ops.method_ptr_size = gnuv3_method_ptr_size; + gnu_v3_abi_ops.make_method_ptr = gnuv3_make_method_ptr; + gnu_v3_abi_ops.method_ptr_to_value = gnuv3_method_ptr_to_value; + gnu_v3_abi_ops.skip_trampoline = gnuv3_skip_trampoline; + gnu_v3_abi_ops.pass_by_reference = gnuv3_pass_by_reference; } +extern initialize_file_ftype _initialize_gnu_v3_abi; /* -Wmissing-prototypes */ void _initialize_gnu_v3_abi (void) { init_gnuv3_ops (); - register_cp_abi (gnu_v3_abi_ops); + register_cp_abi (&gnu_v3_abi_ops); }