diff options
Diffstat (limited to 'gdb/gnu-v2-abi.c')
| -rw-r--r-- | gdb/gnu-v2-abi.c | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/gdb/gnu-v2-abi.c b/gdb/gnu-v2-abi.c index ef46055..2b086c5 100644 --- a/gdb/gnu-v2-abi.c +++ b/gdb/gnu-v2-abi.c @@ -34,6 +34,8 @@ struct cp_abi_ops gnu_v2_abi_ops; static int vb_match (struct type *, int, struct type *); +int gnuv2_baseclass_offset (struct type *type, int index, char *valaddr, + CORE_ADDR address); static enum dtor_kinds gnuv2_is_destructor_name (const char *name) @@ -308,6 +310,100 @@ gnuv2_value_rtti_type (struct value *v, int *full, int *top, int *using_enc) return rtti_type; } +/* Return true if the INDEXth field of TYPE is a virtual baseclass + pointer which is for the base class whose type is BASECLASS. */ + +static int +vb_match (struct type *type, int index, struct type *basetype) +{ + struct type *fieldtype; + char *name = TYPE_FIELD_NAME (type, index); + char *field_class_name = NULL; + + if (*name != '_') + return 0; + /* gcc 2.4 uses _vb$. */ + if (name[1] == 'v' && name[2] == 'b' && is_cplus_marker (name[3])) + field_class_name = name + 4; + /* gcc 2.5 will use __vb_. */ + if (name[1] == '_' && name[2] == 'v' && name[3] == 'b' && name[4] == '_') + field_class_name = name + 5; + + if (field_class_name == NULL) + /* This field is not a virtual base class pointer. */ + return 0; + + /* It's a virtual baseclass pointer, now we just need to find out whether + it is for this baseclass. */ + fieldtype = TYPE_FIELD_TYPE (type, index); + if (fieldtype == NULL + || TYPE_CODE (fieldtype) != TYPE_CODE_PTR) + /* "Can't happen". */ + return 0; + + /* What we check for is that either the types are equal (needed for + nameless types) or have the same name. This is ugly, and a more + elegant solution should be devised (which would probably just push + the ugliness into symbol reading unless we change the stabs format). */ + if (TYPE_TARGET_TYPE (fieldtype) == basetype) + return 1; + + if (TYPE_NAME (basetype) != NULL + && TYPE_NAME (TYPE_TARGET_TYPE (fieldtype)) != NULL + && STREQ (TYPE_NAME (basetype), + TYPE_NAME (TYPE_TARGET_TYPE (fieldtype)))) + return 1; + return 0; +} + +/* Compute the offset of the baseclass which is + the INDEXth baseclass of class TYPE, + for value at VALADDR (in host) at ADDRESS (in target). + The result is the offset of the baseclass value relative + to (the address of)(ARG) + OFFSET. + + -1 is returned on error. */ + +int +gnuv2_baseclass_offset (struct type *type, int index, char *valaddr, + CORE_ADDR address) +{ + struct type *basetype = TYPE_BASECLASS (type, index); + + if (BASETYPE_VIA_VIRTUAL (type, index)) + { + /* Must hunt for the pointer to this virtual baseclass. */ + register int i, len = TYPE_NFIELDS (type); + register int n_baseclasses = TYPE_N_BASECLASSES (type); + + /* First look for the virtual baseclass pointer + in the fields. */ + for (i = n_baseclasses; i < len; i++) + { + if (vb_match (type, i, basetype)) + { + CORE_ADDR addr + = unpack_pointer (TYPE_FIELD_TYPE (type, i), + valaddr + (TYPE_FIELD_BITPOS (type, i) / 8)); + + return addr - (LONGEST) address; + } + } + /* Not in the fields, so try looking through the baseclasses. */ + for (i = index + 1; i < n_baseclasses; i++) + { + int boffset = + baseclass_offset (type, i, valaddr, address); + if (boffset) + return boffset; + } + /* Not found. */ + return -1; + } + + /* Baseclass is easily computed. */ + return TYPE_BASECLASS_BITPOS (type, index) / 8; +} static void init_gnuv2_ops (void) @@ -321,6 +417,7 @@ init_gnuv2_ops (void) 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; + gnu_v2_abi_ops.baseclass_offset = gnuv2_baseclass_offset; } void |