From c4aeac856a297bbcf96e565e5bad277bfcff3c1b Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Thu, 15 Mar 2012 15:43:18 +0000 Subject: [PATCH] * gnu-v3-abi.c (struct value_and_voffset): New. (hash_value_and_voffset, eq_value_and_voffset) (compare_value_and_voffset, compute_vtable_size) (print_one_vtable, gnuv3_print_vtable): New functions. (init_gnuv3_ops): Initialize 'print_vtable' field. * cp-support.c (info_vtbl_command): New function. (_initialize_cp_support): Add "info vtbl". * cp-abi.h (cplus_print_vtable): Declare. (struct cp_abi_ops) : New field. * cp-abi.c (cplus_print_vtable): New function. * NEWS: Update. gdb/testsuite * gdb.cp/virtfunc.exp (make_one_vtable_result): New proc. (test_info_vtbl): Likewise. (do_tests): Call test_info_vtbl. * gdb.cp/virtfunc.cc (va): New global. gdb/doc * gdb.texinfo (Debugging C Plus Plus): Document "info vtbl". --- gdb/ChangeLog | 14 ++ gdb/NEWS | 3 + gdb/cp-abi.c | 10 ++ gdb/cp-abi.h | 6 + gdb/cp-support.c | 18 +++ gdb/doc/ChangeLog | 4 + gdb/doc/gdb.texinfo | 6 + gdb/gnu-v3-abi.c | 241 ++++++++++++++++++++++++++++++ gdb/testsuite/ChangeLog | 7 + gdb/testsuite/gdb.cp/virtfunc.cc | 1 + gdb/testsuite/gdb.cp/virtfunc.exp | 49 ++++++ 11 files changed, 359 insertions(+) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index fccf6673706..1a10f373b60 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,17 @@ +2012-03-15 Tom Tromey + + * gnu-v3-abi.c (struct value_and_voffset): New. + (hash_value_and_voffset, eq_value_and_voffset) + (compare_value_and_voffset, compute_vtable_size) + (print_one_vtable, gnuv3_print_vtable): New functions. + (init_gnuv3_ops): Initialize 'print_vtable' field. + * cp-support.c (info_vtbl_command): New function. + (_initialize_cp_support): Add "info vtbl". + * cp-abi.h (cplus_print_vtable): Declare. + (struct cp_abi_ops) : New field. + * cp-abi.c (cplus_print_vtable): New function. + * NEWS: Update. + 2012-03-15 Tom Tromey * d-lang.c (d_language_defn) : Set to diff --git a/gdb/NEWS b/gdb/NEWS index 7d70404e88c..5ab855cff4d 100644 --- a/gdb/NEWS +++ b/gdb/NEWS @@ -70,6 +70,9 @@ ** "enable count" can be used to auto-disable a breakpoint after several hits. + ** "info vtable" can be used to show the virtual method tables for + C++ and Java objects. + * New targets Renesas RL78 rl78-*-elf diff --git a/gdb/cp-abi.c b/gdb/cp-abi.c index e949088f396..16b53566b58 100644 --- a/gdb/cp-abi.c +++ b/gdb/cp-abi.c @@ -169,6 +169,16 @@ cplus_method_ptr_to_value (struct value **this_p, return (*current_cp_abi.method_ptr_to_value) (this_p, method_ptr); } +/* See cp-abi.h. */ + +void +cplus_print_vtable (struct value *value) +{ + if (current_cp_abi.print_vtable == NULL) + error (_("GDB cannot print the vtable on this target")); + return (*current_cp_abi.print_vtable) (value); +} + int cp_pass_by_reference (struct type *type) { diff --git a/gdb/cp-abi.h b/gdb/cp-abi.h index 0f24e9a9753..84514501ff7 100644 --- a/gdb/cp-abi.h +++ b/gdb/cp-abi.h @@ -173,6 +173,11 @@ struct value *cplus_method_ptr_to_value (struct value **this_p, void cplus_make_method_ptr (struct type *type, gdb_byte *CONTENTS, CORE_ADDR address, int is_virtual); +/* Print the vtable for VALUE, if there is one. If there is no + vtable, print a message, but do not throw. */ + +void cplus_print_vtable (struct value *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. */ @@ -213,6 +218,7 @@ struct cp_abi_ops CORE_ADDR, int); struct value * (*method_ptr_to_value) (struct value **, struct value *); + void (*print_vtable) (struct value *); CORE_ADDR (*skip_trampoline) (struct frame_info *, CORE_ADDR); int (*pass_by_reference) (struct type *type); }; diff --git a/gdb/cp-support.c b/gdb/cp-support.c index 0620aa7dbf6..8d8b69b8605 100644 --- a/gdb/cp-support.c +++ b/gdb/cp-support.c @@ -34,6 +34,7 @@ #include "exceptions.h" #include "expression.h" #include "value.h" +#include "cp-abi.h" #include "safe-ctype.h" @@ -1563,6 +1564,17 @@ cp_validate_operator (const char *input) return 0; } +/* Implement "info vtable". */ + +static void +info_vtbl_command (char *arg, int from_tty) +{ + struct value *value; + + value = parse_and_eval (arg); + cplus_print_vtable (value); +} + void _initialize_cp_support (void) { @@ -1581,4 +1593,10 @@ _initialize_cp_support (void) first_component_command, _("Print the first class/namespace component of NAME."), &maint_cplus_cmd_list); + + add_info ("vtbl", info_vtbl_command, + _("Show the vtable for a C++ object.\n\ +Usage: info vtbl EXPRESSION\n\ +Evaluate EXPRESSION and display the virtual function table for the\n\ +resulting object.")); } diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog index 80dd326c441..8ea02d0edf3 100644 --- a/gdb/doc/ChangeLog +++ b/gdb/doc/ChangeLog @@ -1,3 +1,7 @@ +2012-03-15 Tom Tromey + + * gdb.texinfo (Debugging C Plus Plus): Document "info vtbl". + 2012-03-13 Doug Evans * gdb.texinfo (Help): Change apropos example to use "alias" instead diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index a5022d4d327..d4c56568576 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -12788,6 +12788,12 @@ Print inheritance relationships as well as other information for type @var{typename}. @xref{Symbols, ,Examining the Symbol Table}. +@item info vtbl @var{expression}. +The @code{info vtbl} command can be used to display the virtual +method tables of the object computed by @var{expression}. This shows +one entry per virtual table; there may be multiple virtual tables when +multiple inheritance is in use. + @cindex C@t{++} symbol display @item set print demangle @itemx show print demangle diff --git a/gdb/gnu-v3-abi.c b/gdb/gnu-v3-abi.c index f015af63a96..0ba6ab54f52 100644 --- a/gdb/gnu-v3-abi.c +++ b/gdb/gnu-v3-abi.c @@ -26,6 +26,7 @@ #include "objfiles.h" #include "valprint.h" #include "c-lang.h" +#include "exceptions.h" #include "gdb_assert.h" #include "gdb_string.h" @@ -725,6 +726,245 @@ gnuv3_method_ptr_to_value (struct value **this_p, struct value *method_ptr) return value_from_pointer (lookup_pointer_type (method_type), ptr_value); } +/* Objects of this type are stored in a hash table and a vector when + printing the vtables for a class. */ + +struct value_and_voffset +{ + /* The value representing the object. */ + struct value *value; + + /* The maximum vtable offset we've found for any object at this + offset in the outermost object. */ + int max_voffset; +}; + +typedef struct value_and_voffset *value_and_voffset_p; +DEF_VEC_P (value_and_voffset_p); + +/* Hash function for value_and_voffset. */ + +static hashval_t +hash_value_and_voffset (const void *p) +{ + const struct value_and_voffset *o = p; + + return value_address (o->value) + value_embedded_offset (o->value); +} + +/* Equality function for value_and_voffset. */ + +static int +eq_value_and_voffset (const void *a, const void *b) +{ + const struct value_and_voffset *ova = a; + const struct value_and_voffset *ovb = b; + + return (value_address (ova->value) + value_embedded_offset (ova->value) + == value_address (ovb->value) + value_embedded_offset (ovb->value)); +} + +/* qsort comparison function for value_and_voffset. */ + +static int +compare_value_and_voffset (const void *a, const void *b) +{ + const struct value_and_voffset * const *ova = a; + CORE_ADDR addra = (value_address ((*ova)->value) + + value_embedded_offset ((*ova)->value)); + const struct value_and_voffset * const *ovb = b; + CORE_ADDR addrb = (value_address ((*ovb)->value) + + value_embedded_offset ((*ovb)->value)); + + if (addra < addrb) + return -1; + if (addra > addrb) + return 1; + return 0; +} + +/* A helper function used when printing vtables. This determines the + key (most derived) sub-object at each address and also computes the + maximum vtable offset seen for the corresponding vtable. Updates + OFFSET_HASH and OFFSET_VEC with a new value_and_voffset object, if + needed. VALUE is the object to examine. */ + +static void +compute_vtable_size (htab_t offset_hash, + VEC (value_and_voffset_p) **offset_vec, + struct value *value) +{ + int i; + struct type *type = check_typedef (value_type (value)); + void **slot; + struct value_and_voffset search_vo, *current_vo; + CORE_ADDR addr = value_address (value) + value_embedded_offset (value); + + /* If the object is not dynamic, then we are done; as it cannot have + dynamic base types either. */ + if (!gnuv3_dynamic_class (type)) + return; + + /* Update the hash and the vec, if needed. */ + search_vo.value = value; + slot = htab_find_slot (offset_hash, &search_vo, INSERT); + if (*slot) + current_vo = *slot; + else + { + current_vo = XNEW (struct value_and_voffset); + current_vo->value = value; + current_vo->max_voffset = -1; + *slot = current_vo; + VEC_safe_push (value_and_voffset_p, *offset_vec, current_vo); + } + + /* Update the value_and_voffset object with the highest vtable + offset from this class. */ + for (i = 0; i < TYPE_NFN_FIELDS (type); ++i) + { + int j; + struct fn_field *fn = TYPE_FN_FIELDLIST1 (type, i); + + for (j = 0; j < TYPE_FN_FIELDLIST_LENGTH (type, i); ++j) + { + if (TYPE_FN_FIELD_VIRTUAL_P (fn, j)) + { + int voffset = TYPE_FN_FIELD_VOFFSET (fn, j); + + if (voffset > current_vo->max_voffset) + current_vo->max_voffset = voffset; + } + } + } + + /* Recurse into base classes. */ + for (i = 0; i < TYPE_N_BASECLASSES (type); ++i) + compute_vtable_size (offset_hash, offset_vec, value_field (value, i)); +} + +/* Helper for gnuv3_print_vtable that prints a single vtable. */ + +static void +print_one_vtable (struct gdbarch *gdbarch, struct value *value, + int max_voffset, + struct value_print_options *opts) +{ + int i; + struct type *type = check_typedef (value_type (value)); + struct value *vtable; + CORE_ADDR vt_addr; + + vtable = gnuv3_get_vtable (gdbarch, type, + value_address (value) + + value_embedded_offset (value)); + vt_addr = value_address (value_field (vtable, + vtable_field_virtual_functions)); + + printf_filtered (_("vtable for '%s' @ %s (subobject @ %s):\n"), + TYPE_SAFE_NAME (type), + paddress (gdbarch, vt_addr), + paddress (gdbarch, (value_address (value) + + value_embedded_offset (value)))); + + for (i = 0; i <= max_voffset; ++i) + { + struct value *vfn; + CORE_ADDR addr; + volatile struct gdb_exception ex; + + printf_filtered ("[%d]: ", i); + + vfn = value_subscript (value_field (vtable, + vtable_field_virtual_functions), + i); + + if (gdbarch_vtable_function_descriptors (gdbarch)) + vfn = value_addr (vfn); + + TRY_CATCH (ex, RETURN_MASK_ERROR) + { + addr = value_as_address (vfn); + } + if (ex.reason < 0) + printf_filtered (_(""), ex.message); + else + print_function_pointer_address (gdbarch, addr, gdb_stdout, + opts->addressprint); + printf_filtered ("\n"); + } +} + +/* Implementation of the print_vtable method. */ + +static void +gnuv3_print_vtable (struct value *value) +{ + struct gdbarch *gdbarch; + struct type *type; + struct value *vtable; + struct value_print_options opts; + htab_t offset_hash; + struct cleanup *cleanup; + VEC (value_and_voffset_p) *result_vec; + struct value_and_voffset *iter; + int i, count; + + value = coerce_ref (value); + type = check_typedef (value_type (value)); + if (TYPE_CODE (type) == TYPE_CODE_PTR) + { + value = value_ind (value); + type = check_typedef (value_type (value)); + } + + get_user_print_options (&opts); + + /* Respect 'set print object'. */ + if (opts.objectprint) + { + value = value_full_object (value, NULL, 0, 0, 0); + type = check_typedef (value_type (value)); + } + + gdbarch = get_type_arch (type); + vtable = gnuv3_get_vtable (gdbarch, type, + value_as_address (value_addr (value))); + + if (!vtable) + { + printf_filtered (_("This object does not have a virtual function table\n")); + return; + } + + offset_hash = htab_create_alloc (1, hash_value_and_voffset, + eq_value_and_voffset, + xfree, xcalloc, xfree); + cleanup = make_cleanup_htab_delete (offset_hash); + make_cleanup (VEC_cleanup (value_and_voffset_p), &result_vec); + + compute_vtable_size (offset_hash, &result_vec, value); + + qsort (VEC_address (value_and_voffset_p, result_vec), + VEC_length (value_and_voffset_p, result_vec), + sizeof (value_and_voffset_p), + compare_value_and_voffset); + + count = 0; + for (i = 0; VEC_iterate (value_and_voffset_p, result_vec, i, iter); ++i) + { + if (iter->max_voffset >= 0) + { + if (count > 0) + printf_filtered ("\n"); + print_one_vtable (gdbarch, iter->value, iter->max_voffset, &opts); + ++count; + } + } + + do_cleanups (cleanup); +} + /* 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. */ @@ -873,6 +1113,7 @@ init_gnuv3_ops (void) 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.print_vtable = gnuv3_print_vtable; gnu_v3_abi_ops.skip_trampoline = gnuv3_skip_trampoline; gnu_v3_abi_ops.pass_by_reference = gnuv3_pass_by_reference; } diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index d7975cc6ed3..9aee852ced0 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,10 @@ +2012-03-15 Tom Tromey + + * gdb.cp/virtfunc.exp (make_one_vtable_result): New proc. + (test_info_vtbl): Likewise. + (do_tests): Call test_info_vtbl. + * gdb.cp/virtfunc.cc (va): New global. + 2012-03-15 Thomas Schwinge * gdb.dwarf2/dw2-ada-ffffffff.S: Use .4byte instead of .long for diff --git a/gdb/testsuite/gdb.cp/virtfunc.cc b/gdb/testsuite/gdb.cp/virtfunc.cc index 24a7d0cd0b2..e319863bd44 100644 --- a/gdb/testsuite/gdb.cp/virtfunc.cc +++ b/gdb/testsuite/gdb.cp/virtfunc.cc @@ -111,6 +111,7 @@ D d; E e; V v; VB vb; +VA va; A* pAa = &a; diff --git a/gdb/testsuite/gdb.cp/virtfunc.exp b/gdb/testsuite/gdb.cp/virtfunc.exp index dd41c6dd982..15a374ca1ae 100644 --- a/gdb/testsuite/gdb.cp/virtfunc.exp +++ b/gdb/testsuite/gdb.cp/virtfunc.exp @@ -226,6 +226,54 @@ proc test_virtual_calls {} { } } +# A helper proc that creates a regular expression matching a +# particular vtable. NAME is the type name. Each element of ARGS is +# the name of a function in the vtable. + +proc make_one_vtable_result {name args} { + global hex + + set nls "\[\r\n\]+" + + set result "vtable for '${name}' @ $hex .subobject @ $hex.:$nls" + set count 0 + foreach func $args { + append result ".${count}.: $hex <$func..>${nls}" + incr count + } + + return $result +} + +# Test "info vtbl". + +proc test_info_vtbl {} { + global hex + + set nls "\[\r\n\]+" + + set vt_A [make_one_vtable_result A A::f] + set vt_B [make_one_vtable_result B B::f] + set vt_V [make_one_vtable_result V VB::vvb V::vv] + set vt_V2 [make_one_vtable_result V VB::vvb "virtual thunk to E::vv"] + set vt_D [make_one_vtable_result D D::vg D::vd] + set vt_D2 [make_one_vtable_result D "non-virtual thunk to E::vg" D::vd] + set vt_E [make_one_vtable_result E E::f E::vg E::vv] + + gdb_test "info vtbl a" "${vt_A}${vt_V}" + gdb_test "info vtbl b" "${vt_B}${vt_V}" + gdb_test "info vtbl c" "${vt_V}" + gdb_test "info vtbl d" "${vt_D}${vt_V}" + gdb_test "info vtbl e" "${vt_E}${vt_D2}${vt_V2}" + gdb_test "info vtbl pEe" "${vt_E}${vt_D2}${vt_V2}" + + gdb_test "info vtbl" "Argument required.*" + gdb_test "info vtbl va" \ + "This object does not have a virtual function table.*" + gdb_test "info vtbl all_count" \ + "This object does not have a virtual function table.*" +} + proc do_tests {} { global srcdir subdir binfile global gdb_prompt @@ -244,6 +292,7 @@ proc do_tests {} { return } test_ptype_of_classes + test_info_vtbl gdb_breakpoint test_calls gdb_test "continue" ".*Breakpoint .* test_calls.*" "" -- 2.30.2