diff options
| -rw-r--r-- | gdb/ChangeLog | 15 | ||||
| -rw-r--r-- | gdb/Makefile.in | 8 | ||||
| -rw-r--r-- | gdb/gnu-v3-abi.c | 355 | ||||
| -rw-r--r-- | gdb/minsyms.c | 19 |
4 files changed, 393 insertions, 4 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index b154976..2600102 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,18 @@ +2001-05-22 Jim Blandy <jimb@redhat.com> + + Add support for the GNU V3 C++ ABI. + (Includes changes by Dan Berlin.) + + * gnu-v3-abi.c: New file. + * minsyms.c: #include "value.h" and "cp-abi.h". + (install_minimal_symbols): Check the minimal symbol table for + symbols that look mangled in the V3 style, and select the V3 ABI + if we find any. + * Makefile.in (SFILES): Add gnu-v3-abi.c. + (COMMON_OBS): Add gnu-v3-abi.o. + (gnu-v3-abi.o): Add new rule. + (minsyms.o): Depend on $(cp_abi_h) and $(value_h). + 2001-05-21 Jim Blandy <jimb@redhat.com> * values.c (value_primitive_field): If we're extracting a base diff --git a/gdb/Makefile.in b/gdb/Makefile.in index bdacdbf..6735215 100644 --- a/gdb/Makefile.in +++ b/gdb/Makefile.in @@ -541,7 +541,7 @@ SFILES = ax-general.c ax-gdb.c bcache.c blockframe.c breakpoint.c \ tui/tui-file.h tui/tui-file.c \ ui-file.h ui-file.c \ frame.c \ - gnu-v2-abi.c hpacc-abi.c cp-abi.c + gnu-v2-abi.c gnu-v3-abi.c hpacc-abi.c cp-abi.c LINTFILES = $(SFILES) $(YYFILES) $(CONFIG_SRCS) init.c @@ -695,7 +695,7 @@ COMMON_OBS = version.o blockframe.o breakpoint.o findvar.o regcache.o \ nlmread.o serial.o mdebugread.o os9kread.o top.o utils.o \ ui-file.o tui-file.o \ frame.o \ - gnu-v2-abi.o hpacc-abi.o cp-abi.o + gnu-v2-abi.o gnu-v3-abi.o hpacc-abi.o cp-abi.o OBS = $(COMMON_OBS) $(ANNOTATE_OBS) @@ -1495,6 +1495,8 @@ gnu-nat.o: process_reply_S.h exc_request_S.h notify_S.h msg_reply_S.h \ gnu-v2-abi.o: gnu-v2-abi.c $(defs_h) $(gdb_string_h) $(symtab_h) \ $(gdbtypes_h) $(value_h) $(demangle_h) $(cp_abi_h) +gnu-v3-abi.o: gnu-v2-abi.c $(defs_h) $(value_h) $(cp_abi_h) $(demangle_h) + h8300-tdep.o: h8300-tdep.c $(defs_h) $(frame_h) $(symtab_h) $(regcache_h) h8500-tdep.o: h8500-tdep.c $(bfd_h) $(dis-asm_h) $(defs_h) \ @@ -1679,7 +1681,7 @@ os9kread.o: os9kread.c buildsym.h complaints.h $(bfd_h) $(defs_h) \ mem-break.o: mem-break.c $(defs_h) minsyms.o: minsyms.c $(bfd_h) $(defs_h) objfiles.h symfile.h \ - $(symtab_h) $(gdb_string_h) + $(symtab_h) $(gdb_string_h) $(value_h) $(cp_abi_h) mips-nat.o: mips-nat.c $(defs_h) $(gdbcore_h) $(inferior_h) $(regcache_h) diff --git a/gdb/gnu-v3-abi.c b/gdb/gnu-v3-abi.c new file mode 100644 index 0000000..1bd4ce6 --- /dev/null +++ b/gdb/gnu-v3-abi.c @@ -0,0 +1,355 @@ +/* Abstraction of GNU v3 abi. + Contributed by Jim Blandy <jimb@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 "value.h" +#include "cp-abi.h" +#include "demangle.h" + +struct cp_abi_ops gnu_v3_abi_ops; + +static int +gnuv3_is_vtable_name (const char *name) +{ + return strncmp (name, "_ZTV", 4) == 0; +} + +static int +gnuv3_is_operator_name (const char *name) +{ + return strncmp (name, "operator", 8) == 0; +} + + +/* 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: + + struct gdb_gnu_v3_abi_vtable { + + / * An array of virtual call and virtual base offsets. The real + length of this array depends on the class hierarchy; we use + negative subscripts to access the elements. Yucky, but + better than the alternatives. * / + ptrdiff_t vcall_and_vbase_offsets[0]; + + / * The offset from a virtual pointer referring to this table + to the top of the complete object. * / + ptrdiff_t offset_to_top; + + / * The type_info pointer for this class. This is really a + std::type_info *, but GDB doesn't really look at the + type_info object itself, so we don't bother to get the type + exactly right. * / + void *type_info; + + / * Virtual table pointers in objects point here. * / + + / * Virtual function pointers. Like the vcall/vbase array, the + real length of this table depends on the class hierarchy. * / + void (*virtual_functions[0]) (); + + }; + + The catch, of course, is that the exact layout of this table + depends on the ABI --- word size, endianness, alignment, etc. So + the GDB type object is actually a per-architecture kind of thing. + + vtable_type_gdbarch_data is a gdbarch per-architecture data pointer + which refers to the struct type * for this structure, laid out + appropriately for the architecture. */ +struct gdbarch_data *vtable_type_gdbarch_data; + + +/* Human-readable names for the numbers of the fields above. */ +enum { + vtable_field_vcall_and_vbase_offsets, + vtable_field_offset_to_top, + vtable_field_type_info, + vtable_field_virtual_functions +}; + + +/* Return a GDB type representing `struct gdb_gnu_v3_abi_vtable', + 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. */ +static void * +build_gdb_vtable_type (struct gdbarch *arch) +{ + struct type *t; + struct field *field_list, *field; + int offset; + + struct type *void_ptr_type + = lookup_pointer_type (builtin_type_void); + struct type *ptr_to_void_fn_type + = lookup_pointer_type (lookup_function_type (builtin_type_void)); + + /* 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, + "ptrdiff_t", 0); + + /* We assume no padding is necessary, since GDB doesn't know + anything about alignment at the moment. If this assumption bites + us, we should add a gdbarch method which, given a type, returns + the alignment that type requires, and then use that here. */ + + /* Build the field list. */ + field_list = xmalloc (sizeof (struct field [4])); + memset (field_list, 0, sizeof (struct field [4])); + field = &field_list[0]; + offset = 0; + + /* ptrdiff_t vcall_and_vbase_offsets[0]; */ + 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)); + FIELD_BITPOS (*field) = offset * TARGET_CHAR_BIT; + offset += TYPE_LENGTH (FIELD_TYPE (*field)); + field++; + + /* ptrdiff_t offset_to_top; */ + FIELD_NAME (*field) = "offset_to_top"; + FIELD_TYPE (*field) = ptrdiff_type; + FIELD_BITPOS (*field) = offset * TARGET_CHAR_BIT; + offset += TYPE_LENGTH (FIELD_TYPE (*field)); + field++; + + /* void *type_info; */ + FIELD_NAME (*field) = "type_info"; + FIELD_TYPE (*field) = void_ptr_type; + FIELD_BITPOS (*field) = offset * TARGET_CHAR_BIT; + offset += TYPE_LENGTH (FIELD_TYPE (*field)); + field++; + + /* void (*virtual_functions[0]) (); */ + 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)); + FIELD_BITPOS (*field) = offset * TARGET_CHAR_BIT; + offset += TYPE_LENGTH (FIELD_TYPE (*field)); + field++; + + /* We assumed in the allocation above that there were four fields. */ + if (field != field_list + 4) + abort (); + + t = init_type (TYPE_CODE_STRUCT, offset, 0, 0, 0); + TYPE_NFIELDS (t) = field - field_list; + TYPE_FIELDS (t) = field_list; + TYPE_TAG_NAME (t) = "gdb_gnu_v3_abi_vtable"; + + return t; +} + + +/* 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 () +{ + struct type *vtable_type = gdbarch_data (vtable_type_gdbarch_data); + + return (TYPE_FIELD_BITPOS (vtable_type, vtable_field_virtual_functions) + / TARGET_CHAR_BIT); +} + + +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)); + 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; + LONGEST offset_to_top; + + /* We only have RTTI for class objects. */ + if (TYPE_CODE (value_type) != TYPE_CODE_CLASS) + return NULL; + + /* If we can't find the virtual table pointer for value_type, we + can't find the RTTI. */ + fill_in_vptr_fieldno (value_type); + if (TYPE_VPTR_FIELDNO (value_type) == -1) + return NULL; + + /* Fetch VALUE's virtual table pointer, and tweak it to point at + an instance of our imaginary gdb_gnu_v3_abi_vtable structure. */ + vtable_address + = value_as_pointer (value_field (value, TYPE_VPTR_FIELDNO (value_type))); + vtable = value_at_lazy (vtable_type, + vtable_address - vtable_address_point_offset (), + VALUE_BFD_SECTION (value)); + + /* Find the linker symbol for this vtable. */ + vtable_symbol + = lookup_minimal_symbol_by_pc (VALUE_ADDRESS (vtable) + + VALUE_OFFSET (vtable) + + VALUE_EMBEDDED_OFFSET (vtable)); + if (! vtable_symbol) + return NULL; + + /* The symbol's demangled name should be something like "vtable for + CLASS", where CLASS is the name of the run-time type of VALUE. + If we didn't like this approach, we could instead look in the + type_info object itself to get the class name. But this way + should work just as well, and doesn't read target memory. */ + vtable_symbol_name = SYMBOL_DEMANGLED_NAME (vtable_symbol); + if (strncmp (vtable_symbol_name, "vtable for ", 11)) + error ("can't find linker symbol for virtual table for `%s' value", + TYPE_NAME (value_type)); + 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); + + /* Get the offset from VALUE to the top of the complete object. + NOTE: this is the reverse of the meaning of *TOP_P. */ + offset_to_top + = 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)) + >= TYPE_LENGTH (run_time_type))); + if (top_p) + *top_p = - offset_to_top; + if (using_enc_p) + *using_enc_p = 0; + + return run_time_type; +} + + +static struct value * +gnuv3_virtual_fn_field (struct value **value_p, + struct fn_field *f, int j, + struct type *type, int offset) +{ + 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; + + /* 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) + /* It would be nicer to simply cast the value to the appropriate + base class (and I think that is supposed to be legal), but + value_cast only does the right magic when casting pointers. */ + value = value_ind (value_cast (vfn_base, value_addr (value))); + + /* Now value is an object of the appropriate base type. Fetch its + virtual table. */ + vtable_address + = value_as_pointer (value_field (value, TYPE_VPTR_FIELDNO (vfn_base))); + vtable = value_at_lazy (vtable_type, + vtable_address - vtable_address_point_offset (), + VALUE_BFD_SECTION (value)); + + /* 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))); + + /* Cast the function pointer to the appropriate type. */ + vfn = value_cast (lookup_pointer_type (TYPE_FN_FIELD_TYPE (f, j)), + vfn); + + return vfn; +} + + +static void +init_gnuv3_ops (void) +{ + vtable_type_gdbarch_data = register_gdbarch_data (build_gdb_vtable_type, 0); + + 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_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; +} + + +void +_initialize_gnu_v3_abi (void) +{ + init_gnuv3_ops (); + + register_cp_abi (gnu_v3_abi_ops); +} diff --git a/gdb/minsyms.c b/gdb/minsyms.c index 7608297..0ed38d2 100644 --- a/gdb/minsyms.c +++ b/gdb/minsyms.c @@ -47,6 +47,8 @@ #include "symfile.h" #include "objfiles.h" #include "demangle.h" +#include "value.h" +#include "cp-abi.h" /* Accumulate the minimal symbols for each objfile in bunches of BUNCH_SIZE. At the end, copy them all into one newly allocated location on an objfile's @@ -956,9 +958,24 @@ install_minimal_symbols (struct objfile *objfile) objfile->minimal_symbol_count = mcount; objfile->msymbols = msymbols; + /* Try to guess the appropriate C++ ABI by looking at the names + of the minimal symbols in the table. */ + { + int i; + + for (i = 0; i < mcount; i++) + { + const char *name = SYMBOL_NAME (&objfile->msymbols[i]); + if (name[0] == '_' && name[1] == 'Z') + { + switch_to_cp_abi ("gnu-v3"); + break; + } + } + } + /* Now walk through all the minimal symbols, selecting the newly added ones and attempting to cache their C++ demangled names. */ - for (; mcount-- > 0; msymbols++) SYMBOL_INIT_DEMANGLED_NAME (msymbols, &objfile->symbol_obstack); |