diff options
Diffstat (limited to 'gdb')
| -rw-r--r-- | gdb/NEWS | 8 | ||||
| -rw-r--r-- | gdb/doc/gdb.texinfo | 8 | ||||
| -rw-r--r-- | gdb/record-full.c | 95 | ||||
| -rw-r--r-- | gdb/testsuite/gdb.reverse/maint-print-instruction.c | 25 | ||||
| -rw-r--r-- | gdb/testsuite/gdb.reverse/maint-print-instruction.exp | 75 |
5 files changed, 211 insertions, 0 deletions
@@ -9,6 +9,14 @@ This support requires that GDB be built with Python scripting enabled. +* New commands + +maintenance print record-instruction [ N ] + Print the recorded information for a given instruction. If N is not given + prints how GDB would undo the last instruction executed. If N is negative, + prints how GDB would undo the N-th previous instruction, and if N is + positive, it prints how GDB will redo the N-th following instruction. + *** Changes in GDB 13 * MI version 1 is deprecated, and will be removed in GDB 14. diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index ea54f25..dd8f8bc 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -40542,6 +40542,14 @@ that symbol is described. The type chain produced by this command is a recursive definition of the data type as stored in @value{GDBN}'s data structures, including its flags and contained types. +@kindex maint print record-instruction +@item maint print record-instruction +@itemx maint print record-instruction @var{N} +print how GDB recorded a given instruction. If @var{n} is not positive +number, it prints the values stored by the inferior before the @var{n}-th previous +instruction was exectued. If @var{n} is positive, print the values after the @var{n}-th +following instruction is executed. If @var{n} is not given, 0 is assumed. + @kindex maint selftest @cindex self tests @item maint selftest @r{[}-verbose@r{]} @r{[}@var{filter}@r{]} diff --git a/gdb/record-full.c b/gdb/record-full.c index f830bb1..e3cfa3f 100644 --- a/gdb/record-full.c +++ b/gdb/record-full.c @@ -39,6 +39,7 @@ #include "gdbsupport/gdb_unlinker.h" #include "gdbsupport/byte-vector.h" #include "async-event.h" +#include "valprint.h" #include <signal.h> @@ -2764,6 +2765,90 @@ set_record_full_insn_max_num (const char *args, int from_tty, } } +/* Implement the 'maintenance print record-instruction' command. */ + +static void +maintenance_print_record_instruction (const char *args, int from_tty) +{ + struct record_full_entry *to_print = record_full_list; + + if (args != nullptr) + { + int offset = value_as_long (parse_and_eval (args)); + if (offset > 0) + { + /* Move forward OFFSET instructions. We know we found the + end of an instruction when to_print->type is record_full_end. */ + while (to_print->next != nullptr && offset > 0) + { + to_print = to_print->next; + if (to_print->type == record_full_end) + offset--; + } + if (offset != 0) + error (_("Not enough recorded history")); + } + else + { + while (to_print->prev != nullptr && offset < 0) + { + to_print = to_print->prev; + if (to_print->type == record_full_end) + offset++; + } + if (offset != 0) + error (_("Not enough recorded history")); + } + } + gdb_assert (to_print != nullptr); + + /* Go back to the start of the instruction. */ + while (to_print->prev != nullptr && to_print->prev->type != record_full_end) + to_print = to_print->prev; + + /* if we're in the first record, there are no actual instructions + recorded. Warn the user and leave. */ + if (to_print == &record_full_first) + error (_("Not enough recorded history")); + + while (to_print->type != record_full_end) + { + switch (to_print->type) + { + case record_full_reg: + { + type *regtype = gdbarch_register_type (target_gdbarch (), + to_print->u.reg.num); + value *val + = value_from_contents (regtype, + record_full_get_loc (to_print)); + gdb_printf ("Register %s changed: ", + gdbarch_register_name (target_gdbarch (), + to_print->u.reg.num)); + struct value_print_options opts; + get_user_print_options (&opts); + opts.raw = true; + value_print (val, gdb_stdout, &opts); + gdb_printf ("\n"); + break; + } + case record_full_mem: + { + gdb_byte *b = record_full_get_loc (to_print); + gdb_printf ("%d bytes of memory at address %s changed from:", + to_print->u.mem.len, + print_core_address (target_gdbarch (), + to_print->u.mem.addr)); + for (int i = 0; i < to_print->u.mem.len; i++) + gdb_printf (" %02x", b[i]); + gdb_printf ("\n"); + break; + } + } + to_print = to_print->next; + } +} + void _initialize_record_full (); void _initialize_record_full () @@ -2868,4 +2953,14 @@ When ON, query if PREC cannot record memory change of next instruction."), c = add_alias_cmd ("memory-query", record_full_memory_query_cmds.show, no_class, 1,&show_record_cmdlist); deprecate_cmd (c, "show record full memory-query"); + + add_cmd ("record-instruction", class_maintenance, + maintenance_print_record_instruction, + _("\ +Print a recorded instruction.\n\ +If no argument is provided, print the last instruction recorded.\n\ +If a negative argument is given, prints how the nth previous \ +instruction will be undone.\n\ +If a positive argument is given, prints \ +how the nth following instruction will be redone."), &maintenanceprintlist); } diff --git a/gdb/testsuite/gdb.reverse/maint-print-instruction.c b/gdb/testsuite/gdb.reverse/maint-print-instruction.c new file mode 100644 index 0000000..292af6d --- /dev/null +++ b/gdb/testsuite/gdb.reverse/maint-print-instruction.c @@ -0,0 +1,25 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2022-2023 Free Software Foundation, Inc. + + 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 + 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, see <http://www.gnu.org/licenses/>. */ + +int +main () +{ + int x = 0; + x ++; + x --; + return x; +} diff --git a/gdb/testsuite/gdb.reverse/maint-print-instruction.exp b/gdb/testsuite/gdb.reverse/maint-print-instruction.exp new file mode 100644 index 0000000..41b2817 --- /dev/null +++ b/gdb/testsuite/gdb.reverse/maint-print-instruction.exp @@ -0,0 +1,75 @@ +# Copyright 2022-2023 Free Software Foundation, Inc. + +# 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 +# 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, see <http://www.gnu.org/licenses/>. + +# This file is part of the GDB testsuite. It tests the functionality of +# the maintenance print record-instruction command, but does not check the +# syntax, only if the command finds or fails to find recorded history. +# This is done by putting the inferior in mulpitle states with and without +# history to be printed, then checking if GDB is able to print an +# instruction or not. +# To identify if GDB has printed an instruction, we can see if some +# change is printed, since any instruction must have at least a change +# to the PC. + +if ![supports_reverse] { + return +} + +standard_testfile + +if { [prepare_for_testing "failed to prepare" $testfile $srcfile] } { + return -1 +} + +proc test_print { has_history level test_name } { + gdb_test_multiple "maint print record-instruction $level" $test_name { + -re -wrap ".*Not enough recorded history.*" { + gdb_assert !$has_history $test_name + } + + -re -wrap ".*changed.*" { + gdb_assert $has_history $test_name + } + } +} + +if { ![runto_main] } { + return 0 +} + +#confirm that GDB doesn't go crazy if recording isn't enabled +test_print false "" "print before starting to record" + +if ![supports_process_record] { + # No point in testing the rest if we can't record anything + return +} + +gdb_test_no_output "record" "turn on process record" + +test_print false "" "print before any instruction" + +gdb_test "stepi 3" ".*" "collecting history" +test_print true "" "print current after executing a bit" +test_print true "-1" "print previous after executing a bit" +test_print false "1" "print following after executing a bit" + +gdb_test "reverse-stepi" ".*" "moving back" +test_print true "" "print current after reversing" +test_print true "-1" "print previous after reversing" +test_print true "1" "print following after reversing" + +test_print false "-10" "trying to print too far back" +test_print false "10" "trying to print too far forward" |