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From: "Schimpe, Christina" <christina.schimpe@intel.com>
To: Guinevere Larsen <guinevere@redhat.com>,
	"gdb-patches@sourceware.org" <gdb-patches@sourceware.org>
Subject: RE: [PATCH v2 1/6] gdb/record: Refactor record history
Date: Wed, 13 May 2026 07:54:03 +0000	[thread overview]
Message-ID: <SN7PR11MB763827776662E108B20CF99FF9062@SN7PR11MB7638.namprd11.prod.outlook.com> (raw)
In-Reply-To: <23236510-ef59-4396-91eb-5763725f01cc@redhat.com>

Hi Guinevere,

> -----Original Message-----
> From: Guinevere Larsen <guinevere@redhat.com>
> Sent: Dienstag, 12. Mai 2026 20:51
> To: Schimpe, Christina <christina.schimpe@intel.com>; gdb-
> patches@sourceware.org
> Subject: Re: [PATCH v2 1/6] gdb/record: Refactor record history
> 
> On 5/11/26 12:23 PM, Schimpe, Christina wrote:
> > Hi Guinevere,
> >
> > Please find some further comments below.
> 
> Hi Christina!
> 
> Thanks again for taking such a detailed look at this patch! I have some
> inlined comments, thanks for finding these issues!

No problem, it's always good to see new places in GDB. 😊
I still did not fully get the recording infrastructure TBH, but I am getting closer...

> >> -----Original Message-----
> >> From: Guinevere Larsen <guinevere@redhat.com>
> >> Sent: Donnerstag, 7. Mai 2026 19:38
> >> To: Schimpe, Christina <christina.schimpe@intel.com>; gdb-
> >> patches@sourceware.org
> >> Subject: Re: [PATCH v2 1/6] gdb/record: Refactor record history
> >>
> >> On 5/6/26 6:16 PM, Schimpe, Christina wrote:
> >>> Hi Guinevere,
> >>>
> >>> Thank you for working on this.
> >>> I found two items that might be worth looking at in more detail, but
> >>> apart from that it’s mostly minor nits. Please find my feedback below.
> >>>
> >>> I don’t have much experience with the record feature, so my review is
> >>> a bit slow here. To fully understand this patch, I probably need more
> time,
> >>> but I wanted to share the comments I already have. Sorry for chiming in
> >>> so late. I’ll try again tomorrow, or by Friday at the latest.
> >> Hi! Thank you for noting all the inconsistencies, I'll fix almost all of
> >> them before pushing!
> >>
> >> The one thing I don't think it's a good idea is to make the change from
> >> record_full_list -> record_full_log in this commit... mostly because it
> >> will introduce untold amounts of rebase conflicts. I'll introduce a
> >> following commit to this series that will make that renaming, though :)
> >> --
> >> Cheers,
> >> Guinevere Larsen
> >> It/she
> >>
> >>>> -----Original Message-----
> >>>> From: Guinevere Larsen <guinevere@redhat.com>
> >>>> Sent: Donnerstag, 23. April 2026 17:26
> >>>> To: gdb-patches@sourceware.org
> >>>> Cc: Guinevere Larsen <guinevere@redhat.com>
> >>>> Subject: [PATCH v2 1/6] gdb/record: Refactor record history
> >>>>
> >>>> This is the first step in a large refactor in how GDB keeps execution
> >>>> history.  Rather than using a linked list where multiple entries can
> >>>> describe a single instruction, the history will now be stored in an
> >>>> std::deque, each instruction being one entry in the deque.
> >>>>
> >>>> The choice was initially to use an std::vector, but it would become
> >>>> unwieldy because it needs all the memory to be consecutive, which is
> >>>> hard for 200 thousand entries. Deque was picked because it was a nice
> >>>> midpoint between vector (maximum cache cohesion) and linked list
> >>>> (maximum ease of finding space to store more).
> >>>>
> >>>> Each instruction in memory will be now one record_full_instruction
> >>>> entry, which for this commit just contains a vector of
> >>>> record_full_entry for the effects of the instruction, and the data that
> >>>> was stored in the record_full_end entry (that is, the instruction number
> >>>> and the signal, if any).
> >>>>
> >>>> This change introduced a minimal performance improvement (what's
> >>>> important is that it isn't a degradation) and a  reduction in the total
> >>>> memory footprint of roughly 20% if the entire history is used.
> >>>> ---
> >>>>    gdb/aarch64-tdep.c     |    2 -
> >>>>    gdb/amd64-linux-tdep.c |    3 -
> >>>>    gdb/arm-tdep.c         |    2 -
> >>>>    gdb/i386-linux-tdep.c  |    3 -
> >>>>    gdb/i386-tdep.c        |    4 -
> >>>>    gdb/loongarch-tdep.c   |    2 -
> >>>>    gdb/moxie-tdep.c       |    2 -
> >>>>    gdb/ppc-linux-tdep.c   |    3 -
> >>>>    gdb/record-full.c      | 1180 ++++++++++++++++------------------------
> >>>>    gdb/record-full.h      |    1 -
> >>>>    gdb/riscv-tdep.c       |    3 -
> >>>>    gdb/rs6000-tdep.c      |    4 -
> >>>>    gdb/s390-linux-tdep.c  |    3 -
> >>>>    gdb/s390-tdep.c        |    2 -
> >>>>    14 files changed, 476 insertions(+), 738 deletions(-)
> >>>>
> >>>> diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c
> >>>> index 4befaa2720d..a532992b1d8 100644
> >>>> --- a/gdb/aarch64-tdep.c
> >>>> +++ b/gdb/aarch64-tdep.c
> >>>> @@ -6210,8 +6210,6 @@ aarch64_process_record (struct gdbarch
> >> *gdbarch,
> >>>> struct regcache *regcache,
> >>>>    	       aarch64_record.aarch64_mems[rec_no].len))
> >>>>    	    ret = -1;
> >>>>
> >>>> -      if (record_full_arch_list_add_end ())
> >>>> -	ret = -1;
> >>>>        }
> >>>>
> >>>>      deallocate_reg_mem (&aarch64_record);
> >>>> diff --git a/gdb/amd64-linux-tdep.c b/gdb/amd64-linux-tdep.c
> >>>> index a5ac26654cf..9b23db72bbe 100644
> >>>> --- a/gdb/amd64-linux-tdep.c
> >>>> +++ b/gdb/amd64-linux-tdep.c
> >>>> @@ -1591,9 +1591,6 @@ amd64_linux_record_signal (struct gdbarch
> >>>> *gdbarch,
> >>>>    				     + AMD64_LINUX_frame_size))
> >>>>        return -1;
> >>>>
> >>>> -  if (record_full_arch_list_add_end ())
> >>>> -    return -1;
> >>>> -
> >>>>      return 0;
> >>>>    }
> >>>>
> >>>> diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c
> >>>> index 08cce9dbad8..1ce0927f26b 100644
> >>>> --- a/gdb/arm-tdep.c
> >>>> +++ b/gdb/arm-tdep.c
> >>>> @@ -14911,8 +14911,6 @@ arm_process_record (struct gdbarch
> >> *gdbarch,
> >>>> struct regcache *regcache,
> >>>>    	    }
> >>>>    	}
> >>>>
> >>>> -      if (record_full_arch_list_add_end ())
> >>>> -	ret = -1;
> >>>>        }
> >>>>
> >>>>
> >>>> diff --git a/gdb/i386-linux-tdep.c b/gdb/i386-linux-tdep.c
> >>>> index 23aeccac9fc..4f33766fcdd 100644
> >>>> --- a/gdb/i386-linux-tdep.c
> >>>> +++ b/gdb/i386-linux-tdep.c
> >>>> @@ -949,9 +949,6 @@ i386_linux_record_signal (struct gdbarch
> >> *gdbarch,
> >>>>    				     I386_LINUX_xstate +
> >>>> I386_LINUX_frame_size))
> >>>>        return -1;
> >>>>
> >>>> -  if (record_full_arch_list_add_end ())
> >>>> -    return -1;
> >>>> -
> >>>>      return 0;
> >>>>    }
> >>>>
> >>>>
> >>>> diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c
> >>>> index fa935b5fcdb..fee36b46a73 100644
> >>>> --- a/gdb/i386-tdep.c
> >>>> +++ b/gdb/i386-tdep.c
> >>>> @@ -5201,8 +5201,6 @@ i386_record_vex (struct i386_record_s *ir,
> >> uint8_t
> >>>> vex_w, uint8_t vex_r,
> >>>>        }
> >>>>
> >>>>      record_full_arch_list_add_reg (ir->regcache, ir-
> >>>>> regmap[X86_RECORD_REIP_REGNUM]);
> >>>> -  if (record_full_arch_list_add_end ())
> >>>> -    return -1;
> >>>>
> >>>>      return 0;
> >>>>    }
> >>>> @@ -8359,8 +8357,6 @@ Do you want to stop the program?"),
> >>>>
> >>>>      /* In the future, maybe still need to deal with need_dasm.  */
> >>>>      I386_RECORD_FULL_ARCH_LIST_ADD_REG
> >> (X86_RECORD_REIP_REGNUM);
> >>>> -  if (record_full_arch_list_add_end ())
> >>>> -    return -1;
> >>>>
> >>>>      return 0;
> >>>>
> >>>> diff --git a/gdb/loongarch-tdep.c b/gdb/loongarch-tdep.c
> >>>> index 225b1abb703..5ec6b2a48d0 100644
> >>>> --- a/gdb/loongarch-tdep.c
> >>>> +++ b/gdb/loongarch-tdep.c
> >>>> @@ -2789,8 +2789,6 @@ loongarch_process_record (struct gdbarch
> >>>> *gdbarch, struct regcache *regcache,
> >>>>    					 LOONGARCH_PC_REGNUM))
> >>>>    	return -1;
> >>>>
> >>>> -      if (record_full_arch_list_add_end ())
> >>>> -	return -1;
> >>>>        }
> >>>>
> >>>>      return ret;
> >>>> diff --git a/gdb/moxie-tdep.c b/gdb/moxie-tdep.c
> >>>> index c8a04d21f59..2f8f0186488 100644
> >>>> --- a/gdb/moxie-tdep.c
> >>>> +++ b/gdb/moxie-tdep.c
> >>>> @@ -1040,8 +1040,6 @@ moxie_process_record (struct gdbarch
> >> *gdbarch,
> >>>> struct regcache *regcache,
> >>>>
> >>>>      if (record_full_arch_list_add_reg (regcache, MOXIE_PC_REGNUM))
> >>>>        return -1;
> >>>> -  if (record_full_arch_list_add_end ())
> >>>> -    return -1;
> >>>>      return 0;
> >>>>    }
> >>>>
> >>>> diff --git a/gdb/ppc-linux-tdep.c b/gdb/ppc-linux-tdep.c
> >>>> index 19698eaacbe..e2f53551709 100644
> >>>> --- a/gdb/ppc-linux-tdep.c
> >>>> +++ b/gdb/ppc-linux-tdep.c
> >>>> @@ -1565,9 +1565,6 @@ ppc_linux_record_signal (struct gdbarch
> >> *gdbarch,
> >>>> struct regcache *regcache,
> >>>>      if (record_full_arch_list_add_mem (sp, SIGNAL_FRAMESIZE +
> >>>> sizeof_rt_sigframe))
> >>>>        return -1;
> >>>>
> >>>> -  if (record_full_arch_list_add_end ())
> >>>> -    return -1;
> >>>> -
> >>>>      return 0;
> >>>>    }
> >>>>
> >>>> diff --git a/gdb/record-full.c b/gdb/record-full.c
> >>>> index 69d2c100e57..aac69cee17e 100644
> >>>> --- a/gdb/record-full.c
> >>>> +++ b/gdb/record-full.c
> >>> I think we should include vector, optional and deque directly.
> >>>
> >>>> @@ -72,20 +72,17 @@
> >>>>    #define DEFAULT_RECORD_FULL_INSN_MAX_NUM	200000
> >>>>
> >>>>    #define RECORD_FULL_IS_REPLAY \
> >>>> -  (record_full_list->next || ::execution_direction == EXEC_REVERSE)
> >>>> +  ( (record_full_next_insn != record_full_list.size ()) \
> >>> Nit: No whitespace after the first bracket:
> >>> => ((record_full_next_insn != record_full_list.size ()) \
> >>>
> >>>> +     || ::execution_direction == EXEC_REVERSE)
> >>>>
> >>>>    #define RECORD_FULL_FILE_MAGIC	netorder32(0x20091016)
> >>>>
> >>>>    /* These are the core structs of the process record functionality.
> >>>>
> >>>>       A record_full_entry is a record of the value change of a register
> >>>> -   ("record_full_reg") or a part of memory ("record_full_mem").  And
> each
> >>>> -   instruction must have a struct record_full_entry ("record_full_end")
> >>>> -   that indicates that this is the last struct record_full_entry of this
> >>>> -   instruction.
> >>>> -
> >>>> -   Each struct record_full_entry is linked to "record_full_list" by "prev"
> >>>> -   and "next" pointers.  */
> >>>> +   ("record_full_reg") or a part of memory ("record_full_mem").
> >>>> +   These are saved on the record_full_instruction struct, which also
> >>>> +   contains some extra information, such as delivered signals.  */
> >>>>
> >>>>    struct record_full_mem_entry
> >>>>    {
> >>>> @@ -112,47 +109,14 @@ struct record_full_reg_entry
> >>>>      } u;
> >>>>    };
> >>>>
> >>>> -struct record_full_end_entry
> >>>> -{
> >>>> -  enum gdb_signal sigval;
> >>>> -  ULONGEST insn_num;
> >>>> -};
> >>>> -
> >>>>    enum record_full_type
> >>>>    {
> >>>> -  record_full_end = 0,
> >>>>      record_full_reg,
> >>>>      record_full_mem
> >>>>    };
> >>>>
> >>>> -/* This is the data structure that makes up the execution log.
> >>>> -
> >>>> -   The execution log consists of a single linked list of entries
> >>>> -   of type "struct record_full_entry".  It is doubly linked so that it
> >>>> -   can be traversed in either direction.
> >>>> -
> >>>> -   The start of the list is anchored by a struct called
> >>>> -   "record_full_first".  The pointer "record_full_list" either points
> >>>> -   to the last entry that was added to the list (in record mode), or to
> >>>> -   the next entry in the list that will be executed (in replay mode).
> >>>> -
> >>>> -   Each list element (struct record_full_entry), in addition to next
> >>>> -   and prev pointers, consists of a union of three entry types: mem,
> >>>> -   reg, and end.  A field called "type" determines which entry type is
> >>>> -   represented by a given list element.
> >>>> -
> >>>> -   Each instruction that is added to the execution log is represented
> >>>> -   by a variable number of list elements ('entries').  The instruction
> >>>> -   will have one "reg" entry for each register that is changed by
> >>>> -   executing the instruction (including the PC in every case).  It
> >>>> -   will also have one "mem" entry for each memory change.  Finally,
> >>>> -   each instruction will have an "end" entry that separates it from
> >>>> -   the changes associated with the next instruction.  */
> >>>> -
> >>>>    struct record_full_entry
> >>>>    {
> >>>> -  struct record_full_entry *prev;
> >>>> -  struct record_full_entry *next;
> >>>>      enum record_full_type type;
> >>>>      union
> >>>>      {
> >>>> @@ -160,11 +124,31 @@ struct record_full_entry
> >>>>        struct record_full_reg_entry reg;
> >>>>        /* mem */
> >>>>        struct record_full_mem_entry mem;
> >>>> -    /* end */
> >>>> -    struct record_full_end_entry end;
> >>>>      } u;
> >>>>    };
> >>>>
> >>>> +/* This is the main structure that comprises the execution log.
> >>>> +   Each instruction is comprised of:
> >>>> +   * The instruction number: How many instructions were recorded
> before
> >>>> +     this one;
> >>>> +   * sigval: Whether the inferior received a signal while the following
> >>>> +     instruction was being recorded;
> > It might be worth describing in the comment in which cases this does not
> > have a value, to point out the reason why this is now optional.
> > As I understand it before this patch we used GDB_SIGNAL_0 for this case, is
> that right?
> 
> well, yeah, we used to use GDB_SIGNAL_0, but I think it is better to
> explicitly say "there was no signal" other than say "the signal was 0"
> which is treated as a nothing. It's the problem with NULL/nullptr,
> versus languages where nullptrs aren't allowed and instead accessing an
> unset pointer is just disallowed. I just want to add more mindful usage
> of it to make code safer.
> 
> So I don't think it makes sense to add in a comment why it changed, when
> we instead needed a comment earlier about how to deal with "no signal
> was delivered"

Yes, fine with me. 

> >>>> +   * effects: A list of record_full_entry structures, each of which
> >>>> +     describing one effect that the instruction has on the inferior.
> >>>> +
> >>>> +   Note, the signal is stored in the previous instruction for historical
> >>>> +   reasons.  This is how it was first implemented, and no one has gotten
> >>>> +   around to changing it yet.  */
> >>>> +
> >>>> +struct record_full_instruction
> >>>> +{
> >>>> +  /* This might be different from the index if
> >>>> +     we had to remove the first few instructions.  */
> >>>> +  uint32_t insn_num;
> >>>> +  std::optional<gdb_signal> sigval;
> >>>> +  std::vector<record_full_entry> effects;
> >>>> +};
> >>>> +
> >>>>    /* If true, query if PREC cannot record memory
> >>>>       change of next instruction.  */
> >>>>    bool record_full_memory_query = false;
> >>>> @@ -181,27 +165,25 @@ static detached_regcache
> >>>> *record_full_core_regbuf = NULL;
> >>>>    static std::vector<target_section> record_full_core_sections;
> >>>>    static struct record_full_core_buf_entry *record_full_core_buf_list =
> >> NULL;
> >>>> -/* The following variables are used for managing the linked list that
> >>>> -   represents the execution log.
> >>>> +/* The following variables are used for managing the history of
> executed
> >>>> +   instructions from the inferior.
> >>>>
> >>>> -   record_full_first is the anchor that holds down the beginning of
> >>>> -   the list.
> >>>> +   record_full_list contains all instructions that were fully executed and
> >>>> +   saved to the log, so that we can replay the execution.
> >>>>
> >>>> -   record_full_list serves two functions:
> >>>> -     1) In record mode, it anchors the end of the list.
> >>>> -     2) In replay mode, it traverses the list and points to
> >>>> -	the next instruction that must be emulated.
> >>>> +   record_full_next_insn always points to the next instruction that
> would
> >>>> +   be executed if the inferior executes forward.  In the special case when
> >>>> +   the inferior is not replaying, record_full_next_insn points past the
> >>>> +   end of the history.
> >>>>
> >>>> -   record_full_arch_list_head and record_full_arch_list_tail are used
> >>>> -   to manage a separate list, which is used to build up the change
> >>>> -   elements of the currently executing instruction during record mode.
> >>>> -   When this instruction has been completely annotated in the "arch
> >>>> -   list", it will be appended to the main execution log.  */
> >>>> +   record_full_incomplete_instruction holds a partial instruction, while
> >>>> +   the lower target is disassembling the instruction, or as partial xfers
> are
> >>>> +   happening.  It is manipulated by the "arch list" functions for historical
> >>>> +   reasons.  */
> >>>>
> >>>> -static struct record_full_entry record_full_first;
> >>>> -static struct record_full_entry *record_full_list = &record_full_first;
> >>>> -static struct record_full_entry *record_full_arch_list_head = NULL;
> >>>> -static struct record_full_entry *record_full_arch_list_tail = NULL;
> >>>> +static std::deque<record_full_instruction> record_full_list;
> >>> Given that this is not a list anymore I wonder if we should better call this
> >> sth. like
> >>> record_full_history or record_full_log or even simply
> >> recorded_instructions?
> >>>> +static record_full_instruction record_full_incomplete_instruction;
> >>>> +int record_full_next_insn;
> > Any particular reason why this is not static?
> no, I'll make that change.
> >
> >>>>    /* true ask user. false auto delete the last struct record_full_entry.  */
> >>>>    static bool record_full_stop_at_limit = true;
> >>>> @@ -361,6 +343,14 @@ record_full_target::kill ()
> >>>>      record_kill (this);
> >>>>    }
> >>>>
> >>>> +static void
> >>>> +record_full_reset_incomplete ()
> >>>> +{
> >>>> +  record_full_incomplete_instruction.effects.clear ();
> >>>> +  record_full_incomplete_instruction.sigval.reset ();
> >>>> +  record_full_incomplete_instruction.insn_num = 0;
> >>>> +}
> >>>> +
> >>>>    /* See record-full.h.  */
> >>>>
> >>>>    int
> >>>> @@ -390,156 +380,120 @@ static struct cmd_list_element
> >>>> *show_record_full_cmdlist;
> >>>>    /* Command list for "record full".  */
> >>>>    static struct cmd_list_element *record_full_cmdlist;
> >>>>
> >>>> -static void record_full_goto_insn (struct record_full_entry *entry,
> >>>> +static void record_full_goto_insn (size_t target_insn,
> >>>>    				   enum exec_direction_kind dir);
> >>>>
> >>>> -/* Alloc and free functions for record_full_reg, record_full_mem, and
> >>>> -   record_full_end entries.  */
> >>>> +/* Initialization and cleanup functions for record_full_reg and
> >>>> +   record_full_mem entries.  */
> >>>>
> >>>> -/* Alloc a record_full_reg record entry.  */
> >>>> +/* Init a record_full_reg record entry.  */
> >>>>
> >>>> -static inline struct record_full_entry *
> >>>> -record_full_reg_alloc (struct regcache *regcache, int regnum)
> >>>> +static inline struct record_full_entry
> >>>> +record_full_reg_init (struct regcache *regcache, int regnum)
> >>>>    {
> >>>> -  struct record_full_entry *rec;
> >>>> +  struct record_full_entry rec;
> >>>>      struct gdbarch *gdbarch = regcache->arch ();
> >>>>
> >>>> -  rec = XCNEW (struct record_full_entry);
> >>>> -  rec->type = record_full_reg;
> >>>> -  rec->u.reg.num = regnum;
> >>>> -  rec->u.reg.len = register_size (gdbarch, regnum);
> >>>> -  if (rec->u.reg.len > sizeof (rec->u.reg.u.buf))
> >>>> -    rec->u.reg.u.ptr = (gdb_byte *) xmalloc (rec->u.reg.len);
> >>>> +  rec.type = record_full_reg;
> >>>> +  rec.u.reg.num = regnum;
> >>>> +  rec.u.reg.len = register_size (gdbarch, regnum);
> >>>> +  if (rec.u.reg.len > sizeof (rec.u.reg.u.buf))
> >>>> +    rec.u.reg.u.ptr = (gdb_byte *) xmalloc (rec.u.reg.len);
> >>>>
> >>>>      return rec;
> >>>>    }
> >>>>
> >>>> -/* Free a record_full_reg record entry.  */
> >>>> +/* Cleanup a record_full_reg record entry.  */
> >>>>
> >>>>    static inline void
> >>>> -record_full_reg_release (struct record_full_entry *rec)
> >>>> +record_full_reg_cleanup (struct record_full_entry rec)
> >>>>    {
> >>>> -  gdb_assert (rec->type == record_full_reg);
> >>>> -  if (rec->u.reg.len > sizeof (rec->u.reg.u.buf))
> >>>> -    xfree (rec->u.reg.u.ptr);
> >>>> -  xfree (rec);
> >>>> +  gdb_assert (rec.type == record_full_reg);
> >>>> +  if (rec.u.reg.len > sizeof (rec.u.reg.u.buf))
> >>>> +    xfree (rec.u.reg.u.ptr);
> >>>>    }
> >>>>
> >>>> -/* Alloc a record_full_mem record entry.  */
> >>>> +/* Init a record_full_mem record entry.  */
> >>>>
> >>>> -static inline struct record_full_entry *
> >>>> -record_full_mem_alloc (CORE_ADDR addr, int len)
> >>>> +static inline struct record_full_entry
> >>>> +record_full_mem_init (CORE_ADDR addr, int len)
> >>>>    {
> >>>> -  struct record_full_entry *rec;
> >>>> +  struct record_full_entry rec;
> >>>>
> >>>> -  rec = XCNEW (struct record_full_entry);
> >>>> -  rec->type = record_full_mem;
> >>>> -  rec->u.mem.addr = addr;
> >>>> -  rec->u.mem.len = len;
> >>>> -  if (rec->u.mem.len > sizeof (rec->u.mem.u.buf))
> >>>> -    rec->u.mem.u.ptr = (gdb_byte *) xmalloc (len);
> >>>> +  rec.type = record_full_mem;
> >>>> +  rec.u.mem.addr = addr;
> >>>> +  rec.u.mem.len = len;
> >>>> +  if (rec.u.mem.len > sizeof (rec.u.mem.u.buf))
> >>>> +    rec.u.mem.u.ptr = (gdb_byte *) xmalloc (len);
> >>>> +  rec.u.mem.mem_entry_not_accessible = 0;
> >>>>
> >>>>      return rec;
> >>>>    }
> >>>>
> >>>> -/* Free a record_full_mem record entry.  */
> >>>> +/* Cleanup a record_full_mem record entry.  */
> >>>>
> >>>>    static inline void
> >>>> -record_full_mem_release (struct record_full_entry *rec)
> >>>> -{
> >>>> -  gdb_assert (rec->type == record_full_mem);
> >>>> -  if (rec->u.mem.len > sizeof (rec->u.mem.u.buf))
> >>>> -    xfree (rec->u.mem.u.ptr);
> >>>> -  xfree (rec);
> >>>> -}
> >>>> -
> >>>> -/* Alloc a record_full_end record entry.  */
> >>>> -
> >>>> -static inline struct record_full_entry *
> >>>> -record_full_end_alloc (void)
> >>>> +record_full_mem_cleanup (struct record_full_entry rec)
> >>>>    {
> >>>> -  struct record_full_entry *rec;
> >>>> -
> >>>> -  rec = XCNEW (struct record_full_entry);
> >>>> -  rec->type = record_full_end;
> >>>> -
> >>>> -  return rec;
> >>>> +  gdb_assert (rec.type == record_full_mem);
> >>>> +  if (rec.u.mem.len > sizeof (rec.u.mem.u.buf))
> >>>> +    xfree (rec.u.mem.u.ptr);
> >>>>    }
> >>>>
> >>>> -/* Free a record_full_end record entry.  */
> >>>> +/* Free one record entry, any type.  */
> >>>>
> >>>>    static inline void
> >>>> -record_full_end_release (struct record_full_entry *rec)
> >>>> -{
> >>>> -  xfree (rec);
> >>>> -}
> >>>> -
> >>>> -/* Free one record entry, any type.
> >>>> -   Return entry->type, in case caller wants to know.  */
> >>>> -
> >>>> -static inline enum record_full_type
> >>>> -record_full_entry_release (struct record_full_entry *rec)
> >>>> +record_full_entry_cleanup (struct record_full_entry rec)
> >>>>    {
> >>>> -  enum record_full_type type = rec->type;
> >>>>
> >>>> -  switch (type) {
> >>>> +  switch (rec.type) {
> >>>>      case record_full_reg:
> >>>> -    record_full_reg_release (rec);
> >>>> +    record_full_reg_cleanup (rec);
> >>>>        break;
> >>>>      case record_full_mem:
> >>>> -    record_full_mem_release (rec);
> >>>> -    break;
> >>>> -  case record_full_end:
> >>>> -    record_full_end_release (rec);
> >>>> +    record_full_mem_cleanup (rec);
> >>>>        break;
> >>>>      }
> >>>> -  return type;
> >>>>    }
> >>>>
> >>>> -/* Free all record entries in list pointed to by REC.  */
> >>>> -
> >>>>    static void
> >>>> -record_full_list_release (struct record_full_entry *rec)
> >>>> +record_full_reset_history ()
> >>>>    {
> >>>> -  if (!rec)
> >>>> -    return;
> >>>> -
> >>>> -  while (rec->next)
> >>>> -    rec = rec->next;
> >>>> +  record_full_insn_num = 0;
> >>>> +  record_full_insn_count = 0;
> >>>> +  record_full_next_insn = 0;
> >>>>
> >>>> -  while (rec->prev)
> >>>> +  for (auto &insn : record_full_list)
> >>>>        {
> >>>> -      rec = rec->prev;
> >>>> -      record_full_entry_release (rec->next);
> >>>> +      for (auto &entry : insn.effects)
> >>>> +	record_full_entry_cleanup (entry);
> >>>>        }
> >>>>
> >>>> -  if (rec == &record_full_first)
> >>>> -    {
> >>>> -      record_full_insn_num = 0;
> >>>> -      record_full_first.next = NULL;
> >>>> -    }
> >>>> -  else
> >>>> -    record_full_entry_release (rec);
> >>>> +  record_full_list.clear ();
> >>>>    }
> >>>>
> >>>> -/* Free all record entries forward of the given list position.  */
> >>>> -
> >>>>    static void
> >>>> -record_full_list_release_following (struct record_full_entry *rec)
> >>>> +record_full_list_release_following (int index)
> >>>>    {
> >>>> -  struct record_full_entry *tmp = rec->next;
> >>>> -
> >>>> -  rec->next = NULL;
> >>>> -  while (tmp)
> >>>> +  for (int i = record_full_list.size () - 1; i > index; i--)
> >>>>        {
> >>>> -      rec = tmp->next;
> >>>> -      if (record_full_entry_release (tmp) == record_full_end)
> >>>> -	{
> >>>> -	  record_full_insn_num--;
> >>>> -	  record_full_insn_count--;
> >>>> -	}
> >>>> -      tmp = rec;
> >>>> +      for (auto &entry : record_full_list[i].effects)
> >>>> +	record_full_entry_cleanup (entry);
> >>>> +      record_full_list.pop_back ();
> >>>>        }
> >>>> +  /* Set the next instruction to be past the end of the log so we
> >>>> +     start recording if the user moves forward again.  */
> >>>> +  record_full_next_insn = index;
> >>>> +}
> >>>> +static void
> >>>> +record_full_save_instruction ()
> > A function comment would be nice.
> >
> >>>> +{
> >>>> +  ++record_full_insn_count;
> >>>> +  record_full_incomplete_instruction.insn_num =
> record_full_insn_count;
> >>>> +  record_full_incomplete_instruction.effects.shrink_to_fit ();
> >>>> +  record_full_list.push_back (record_full_incomplete_instruction);
> > I think this line will at some point call the default copy constructor of
> record_full_mem_entry
> > and record_full_reg_entry, which have those buffers:
> >
> > gdb_byte buf[sizeof (gdb_byte *)];
> >
> > IIUC you'll only have a shallow copy. Should we use a std::move instead
> here?
> Might be worth, yeah...
> >
> > I further wonder if this problem might be related to the double free issues
> you
> > describe in patch #3. Would you mind checking?
> I did check it! When I was working on patch #3, I disabled copy
> construction, only allowed move constructor/assignment because I
> specifically thought that the vector push_back was the reason for the
> double frees, but it still happened.

That's weird, it would have perfectly explained it.
So with std::move we still have this problem?
Would you mind sharing some backtrace of this double free error ?

> > And if you add the destructor, I think it would make sense to add a copy
> constructor etc., too:
> > https://en.cppreference.com/cpp/language/rule_of_three
> >
> >>>> +  record_full_next_insn++;
> >>>>    }
> >>>>
> >>>>    /* Delete the first instruction from the beginning of the log, to make
> >>>> @@ -550,52 +504,22 @@ record_full_list_release_following (struct
> >>>> record_full_entry *rec)
> >>>>    static void
> >>>>    record_full_list_release_first (void)
> >>>>    {
> >>>> -  struct record_full_entry *tmp;
> >>>> -
> >>>> -  if (!record_full_first.next)
> >>>> +  if (record_full_list.empty ())
> >>>>        return;
> >>>>
> >>>> -  /* Loop until a record_full_end.  */
> >>>> -  while (1)
> >>>> -    {
> >>>> -      /* Cut record_full_first.next out of the linked list.  */
> >>>> -      tmp = record_full_first.next;
> >>>> -      record_full_first.next = tmp->next;
> >>>> -      tmp->next->prev = &record_full_first;
> >>>> -
> >>>> -      /* tmp is now isolated, and can be deleted.  */
> >>>> -      if (record_full_entry_release (tmp) == record_full_end)
> >>>> -	break;	/* End loop at first record_full_end.  */
> >>>> +  for (auto &entry : record_full_list[0].effects)
> >>>> +    record_full_entry_cleanup (entry);
> >>>>
> >>>> -      if (!record_full_first.next)
> >>>> -	{
> >>>> -	  gdb_assert (record_full_insn_num == 1);
> >>>> -	  break;	/* End loop when list is empty.  */
> >>>> -	}
> >>>> -    }
> >>>> +  record_full_list.pop_front ();
> >>>> +  --record_full_next_insn;
> >>>>    }
> >>>>
> >>>>    /* Add a struct record_full_entry to record_full_arch_list.  */
> >>>>
> >>>>    static void
> >>>> -record_full_arch_list_add (struct record_full_entry *rec)
> >>>> +record_full_arch_list_add (struct record_full_entry &rec)
> >>>>    {
> >>>> -  if (record_debug > 1)
> >>>> -    gdb_printf (gdb_stdlog,
> >>>> -		"Process record: record_full_arch_list_add %s.\n",
> >>>> -		host_address_to_string (rec));
> >>>> -
> >>>> -  if (record_full_arch_list_tail)
> >>>> -    {
> >>>> -      record_full_arch_list_tail->next = rec;
> >>>> -      rec->prev = record_full_arch_list_tail;
> >>>> -      record_full_arch_list_tail = rec;
> >>>> -    }
> >>>> -  else
> >>>> -    {
> >>>> -      record_full_arch_list_head = rec;
> >>>> -      record_full_arch_list_tail = rec;
> >>>> -    }
> >>>> +  record_full_incomplete_instruction.effects.push_back (rec);
> >>>>    }
> >>>>
> >>>>    /* Return the value storage location of a record entry.  */
> >>>> @@ -613,7 +537,6 @@ record_full_get_loc (struct record_full_entry
> *rec)
> >>>>          return rec->u.reg.u.ptr;
> >>>>        else
> >>>>          return rec->u.reg.u.buf;
> >>>> -  case record_full_end:
> >>>>      default:
> >>>>        gdb_assert_not_reached ("unexpected record_full_entry type");
> >>>>        return NULL;
> >>>> @@ -625,7 +548,7 @@ record_full_get_loc (struct record_full_entry
> *rec)
> >>>>    int
> >>>>    record_full_arch_list_add_reg (struct regcache *regcache, int regnum)
> >>>>    {
> >>>> -  struct record_full_entry *rec;
> >>>> +  struct record_full_entry rec;
> >>> I think we can omit the struct keyword here (there are some more
> >> occurrences in this patch).
> >>>>      if (record_debug > 1)
> >>>>        gdb_printf (gdb_stdlog,
> >>>> @@ -633,9 +556,9 @@ record_full_arch_list_add_reg (struct regcache
> >>>> *regcache, int regnum)
> >>>>    		"record list.\n",
> >>>>    		regnum);
> >>>>
> >>>> -  rec = record_full_reg_alloc (regcache, regnum);
> >>>> +  rec = record_full_reg_init (regcache, regnum);
> >>>>
> >>>> -  regcache->cooked_read (regnum, record_full_get_loc (rec));
> >>>> +  regcache->cooked_read (regnum, record_full_get_loc (&rec));
> >>>>
> >>>>      record_full_arch_list_add (rec);
> >>>>
> >>>> @@ -648,7 +571,7 @@ record_full_arch_list_add_reg (struct regcache
> >>>> *regcache, int regnum)
> >>>>    int
> >>>>    record_full_arch_list_add_mem (CORE_ADDR addr, int len)
> >>>>    {
> >>>> -  struct record_full_entry *rec;
> >>>> +  struct record_full_entry rec;
> >>>>
> >>>>      if (record_debug > 1)
> >>>>        gdb_printf (gdb_stdlog,
> >>>> @@ -659,12 +582,12 @@ record_full_arch_list_add_mem
> (CORE_ADDR
> >> addr,
> >>>> int len)
> >>>>      if (!addr)	/* FIXME: Why?  Some arch must permit it...  */
> >>>>        return 0;
> >>>>
> >>>> -  rec = record_full_mem_alloc (addr, len);
> >>>> +  rec = record_full_mem_init (addr, len);
> >>>>
> >>>>      if (record_read_memory (current_inferior ()->arch (), addr,
> >>>> -			  record_full_get_loc (rec), len))
> >>>> +			  record_full_get_loc (&rec), len))
> >>>>        {
> >>>> -      record_full_mem_release (rec);
> >>>> +      record_full_mem_cleanup (rec);
> >>>>          return -1;
> >>>>        }
> >>>>
> >>>> @@ -673,27 +596,6 @@ record_full_arch_list_add_mem (CORE_ADDR
> >> addr,
> >>>> int len)
> >>>>      return 0;
> >>>>    }
> >>>>
> >>>> -/* Add a record_full_end type struct record_full_entry to
> >>>> -   record_full_arch_list.  */
> >>>> -
> >>>> -int
> >>>> -record_full_arch_list_add_end (void)
> >>>> -{
> >>>> -  struct record_full_entry *rec;
> >>>> -
> >>>> -  if (record_debug > 1)
> >>>> -    gdb_printf (gdb_stdlog,
> >>>> -		"Process record: add end to arch list.\n");
> >>>> -
> >>>> -  rec = record_full_end_alloc ();
> >>>> -  rec->u.end.sigval = GDB_SIGNAL_0;
> >>>> -  rec->u.end.insn_num = ++record_full_insn_count;
> >>>> -
> >>>> -  record_full_arch_list_add (rec);
> >>>> -
> >>>> -  return 0;
> >>>> -}
> >>>> -
> >>>>    static void
> >>>>    record_full_check_insn_num (void)
> >>>>    {
> >>>> @@ -725,8 +627,7 @@ record_full_message (struct regcache
> *regcache,
> >>>> enum gdb_signal signal)
> >>>>
> >>>>      try
> >>>>        {
> >>>> -      record_full_arch_list_head = NULL;
> >>>> -      record_full_arch_list_tail = NULL;
> >>>> +      record_full_reset_incomplete ();
> >>>>
> >>>>          /* Check record_full_insn_num.  */
> >>>>          record_full_check_insn_num ();
> >>>> @@ -746,20 +647,16 @@ record_full_message (struct regcache
> >> *regcache,
> >>>> enum gdb_signal signal)
> >>>>    	 the user says something different, like "deliver this signal"
> >>>>    	 during the replay mode).
> >>>>
> >>>> -	 User should understand that nothing he does during the replay
> >>>> -	 mode will change the behavior of the child.  If he tries,
> >>>> +	 User should understand that nothing they do during the replay
> >>>> +	 mode will change the behavior of the child.  If they try,
> >>>>    	 then that is a user error.
> >>>>
> >>>>    	 But we should still deliver the signal to gdb during the replay,
> >>>>    	 if we delivered it during the recording.  Therefore we should
> >>>>    	 record the signal during record_full_wait, not
> >>>>    	 record_full_resume.  */
> >>>> -      if (record_full_list != &record_full_first)  /* FIXME better way
> >>>> -						      to check */
> >>>> -	{
> >>>> -	  gdb_assert (record_full_list->type == record_full_end);
> >>>> -	  record_full_list->u.end.sigval = signal;
> >>>> -	}
> >>>> +      if (signal != GDB_SIGNAL_0)
> >>>> +	record_full_list[record_full_next_insn - 1].sigval = signal;
> > Similar comment as already in my earlier review:
> > Can record_full_next_insn be == 0 here or may record_full_list be empty ?
> Oh you're right. This is probably because I misunderstood the order of
> operations and was saving it to the current one, not the previous one,
> and when I fixed that I forgot to check the original
> >
> > I think it might be worth checking the patch if there are more similar issues.
> > The old patch had more guards to check this.
> yeah good point, I'll look through the changes and see if I notice it
> anywhere else.
> >
> > And I noticed in some other locations you cast it:
> >
> > 	  if (sigval != GDB_SIGNAL_0)
> > 	    record_full_incomplete_instruction.sigval = (gdb_signal) sigval;
> >
> > Not sure if this is necessary or not, but it might be for checking and making
> it consistent?
> I cast it in the other location because it is reading from the BFD and
> so sigval is declared as uint8_t, not as gdb_signal.
> > And is it intended that now we don't clear sigval anymore?
> >
> > Shouldn't we set it to  std::nullopt in case signal == GDB_SIGNAL_0,  to
> match the original
> > behaviour?
> 
> yeah this is a mistake. The plan was that record_full_save_instruction
> clears the incomplete instruction, but I apparently forgot that.
> 
> With that, it should always be clear so we won't need to explicitly set
> it to nullopt.
> 
> I'll update the correct function.
> 
> >
> >>>>          if (signal == GDB_SIGNAL_0
> >>>>    	  || !gdbarch_process_record_signal_p (gdbarch))
> >>>> @@ -778,13 +675,11 @@ record_full_message (struct regcache
> >> *regcache,
> >>>> enum gdb_signal signal)
> >>>>        }
> >>>>      catch (const gdb_exception &ex)
> >>>>        {
> >>>> -      record_full_list_release (record_full_arch_list_tail);
> >>>> +      record_full_reset_incomplete ();
> >>>>          throw;
> >>>>        }
> >>>>
> >>>> -  record_full_list->next = record_full_arch_list_head;
> >>>> -  record_full_arch_list_head->prev = record_full_list;
> >>>> -  record_full_list = record_full_arch_list_tail;
> >>>> +  record_full_save_instruction ();
> >>>>
> >>>>      if (record_full_insn_num == record_full_insn_max_num)
> >>>>        record_full_list_release_first ();
> >>>> @@ -829,9 +724,9 @@ static enum target_stop_reason
> >>>> record_full_stop_reason
> >>>>       entries and memory entries, followed by an 'end' entry.  */
> >>>>
> >>>>    static inline void
> >>>> -record_full_exec_insn (struct regcache *regcache,
> >>>> -		       struct gdbarch *gdbarch,
> >>>> -		       struct record_full_entry *entry)
> >>>> +record_full_exec_entry (struct regcache *regcache,
> >>>> +			struct gdbarch *gdbarch,
> >>>> +			struct record_full_entry *entry)
> >>> Nit: omit struct keywords
> >>> And there are some more places in this series/patch, but I will stop
> >> commenting
> >>> now on all of them.
> >>>
> >>>>    {
> >>>>      switch (entry->type)
> >>>>        {
> >>>> @@ -909,6 +804,15 @@ record_full_exec_insn (struct regcache
> >> *regcache,
> >>>>        }
> >>>>    }
> >>>>
> >>>> +static inline void
> >>>> +record_full_exec_insn (struct regcache *regcache,
> >>>> +		       struct gdbarch *gdbarch,
> >>>> +		       record_full_instruction &insn)
> >>>> +{
> >>>> +  for (auto &entry : insn.effects)
> >>>> +    record_full_exec_entry (regcache, gdbarch, &entry);
> >>>> +}
> >>>> +
> >>>>    static void record_full_restore (struct bfd &cbfd);
> >>>>
> >>>>    /* Asynchronous signal handle registered as event loop source for
> when
> >>>> @@ -983,10 +887,7 @@ record_full_open (const char *args, int
> from_tty)
> >>>>      record_preopen ();
> >>>>
> >>>>      /* Reset */
> >>>> -  record_full_insn_num = 0;
> >>>> -  record_full_insn_count = 0;
> >>>> -  record_full_list = &record_full_first;
> >>>> -  record_full_list->next = NULL;
> >>>> +  record_full_reset_history ();
> >>>>
> >>>>      bfd *cbfd = get_inferior_core_bfd (current_inferior ());
> >>>>      if (cbfd != nullptr)
> >>>> @@ -1014,7 +915,7 @@ record_full_base_target::close ()
> >>>>      if (record_debug)
> >>>>        gdb_printf (gdb_stdlog, "Process record: record_full_close\n");
> >>>>
> >>>> -  record_full_list_release (record_full_list);
> >>>> +  record_full_reset_history ();
> >>>>
> >>>>      /* Release record_full_core_regbuf.  */
> >>>>      if (record_full_core_regbuf)
> >>>> @@ -1313,7 +1214,6 @@ record_full_wait_1 (struct target_ops *ops,
> >>>>          struct gdbarch *gdbarch = regcache->arch ();
> >>>>          const address_space *aspace = current_inferior ()->aspace.get ();
> >>>>          int continue_flag = 1;
> >>>> -      int first_record_full_end = 1;
> >>>>
> >>>>          try
> >>>>    	{
> >>>> @@ -1322,7 +1222,6 @@ record_full_wait_1 (struct target_ops *ops,
> >>>>    	  record_full_stop_reason = TARGET_STOPPED_BY_NO_REASON;
> >>>>    	  status->set_stopped (GDB_SIGNAL_0);
> >>>>
> >>>> -	  /* Check breakpoint when forward execute.  */
> >>>>    	  if (execution_direction == EXEC_FORWARD)
> >>>>    	    {
> >>>>    	      tmp_pc = regcache_read_pc (regcache);
> >>>> @@ -1330,8 +1229,7 @@ record_full_wait_1 (struct target_ops *ops,
> >>>>
> >>>> &record_full_stop_reason))
> >>>>    		{
> >>>>    		  if (record_debug)
> >>>> -		    gdb_printf (gdb_stdlog,
> >>>> -				"Process record: break at %s.\n",
> >>>> +		    gdb_printf (gdb_stdlog, "Process record: break at %s.\n",
> >>>>    				paddress (gdbarch, tmp_pc));
> >>>>    		  goto replay_out;
> >>>>    		}
> >>>> @@ -1344,10 +1242,10 @@ record_full_wait_1 (struct target_ops
> *ops,
> >>>>    	     the signal.  */
> >>>>    	  target_terminal::ours ();
> >>>>
> >>>> -	  /* In EXEC_FORWARD mode, record_full_list points to the tail of
> >> prev
> >>>> -	     instruction.  */
> >>>> -	  if (execution_direction == EXEC_FORWARD && record_full_list-
> >>> next)
> >>>> -	    record_full_list = record_full_list->next;
> >>>> +	  /* In EXEC_FORWARD mode, record_full_next_insn is the next
> >>>> +	     instruction to be executed.  */
> >>>> +	  if (execution_direction == EXEC_REVERSE)
> >>>> +	    record_full_next_insn--;
> >>>>
> >>>>    	  /* Loop over the record_full_list, looking for the next place to
> >>>>    	     stop.  */
> >>>> @@ -1355,108 +1253,92 @@ record_full_wait_1 (struct target_ops
> *ops,
> >>>>    	    {
> >>>>    	      /* Check for beginning and end of log.  */
> >>>>    	      if (execution_direction == EXEC_REVERSE
> >>>> -		  && record_full_list == &record_full_first)
> >>>> +		  && record_full_next_insn < 0)
> >>>>    		{
> >>>>    		  /* Hit beginning of record log in reverse.  */
> >>>>    		  status->set_no_history ();
> >>>> +		  record_full_next_insn = 0;
> >>>>    		  break;
> >>>>    		}
> >>>>    	      if (execution_direction != EXEC_REVERSE
> >>>> -		  && !record_full_list->next)
> >>>> +		  && record_full_next_insn == record_full_list.size ())
> >>>>    		{
> >>>>    		  /* Hit end of record log going forward.  */
> >>>>    		  status->set_no_history ();
> >>>>    		  break;
> >>>>    		}
> >>>>
> >>>> -	      record_full_exec_insn (regcache, gdbarch, record_full_list);
> >>>> +	      record_full_exec_insn
> >>>> +		(regcache, gdbarch,
> >>>> +		 record_full_list[record_full_next_insn]);
> >>>>
> >>>> -	      if (record_full_list->type == record_full_end)
> >>>> +	      /* step */
> >>>> +	      if (record_full_resume_step)
> >>>>    		{
> >>>>    		  if (record_debug > 1)
> >>>> -		    gdb_printf
> >>>> -		      (gdb_stdlog,
> >>>> -		       "Process record: record_full_end %s to "
> >>>> -		       "inferior.\n",
> >>>> -		       host_address_to_string (record_full_list));
> >>>> -
> >>>> -		  if (first_record_full_end
> >>>> -		      && execution_direction == EXEC_REVERSE)
> >>>> -		    {
> >>>> -		      /* When reverse execute, the first
> >>>> -			 record_full_end is the part of current
> >>>> -			 instruction.  */
> >>>> -		      first_record_full_end = 0;
> >>>> -		    }
> >>>> -		  else
> >>>> -		    {
> >>>> -		      /* In EXEC_REVERSE mode, this is the
> >>>> -			 record_full_end of prev instruction.  In
> >>>> -			 EXEC_FORWARD mode, this is the
> >>>> -			 record_full_end of current instruction.  */
> >>>> -		      /* step */
> >>>> -		      if (record_full_resume_step)
> >>>> -			{
> >>>> -			  if (record_debug > 1)
> >>>> -			    gdb_printf (gdb_stdlog,
> >>>> -					"Process record: step.\n");
> >>>> -			  continue_flag = 0;
> >>>> -			}
> >>>> -
> >>>> -		      /* check breakpoint */
> >>>> -		      tmp_pc = regcache_read_pc (regcache);
> >>>> -		      if (record_check_stopped_by_breakpoint
> >>>> -			  (aspace, tmp_pc, &record_full_stop_reason))
> >>>> -			{
> >>>> -			  if (record_debug)
> >>>> -			    gdb_printf (gdb_stdlog,
> >>>> -					"Process record: break "
> >>>> -					"at %s.\n",
> >>>> -					paddress (gdbarch, tmp_pc));
> >>>> +		    gdb_printf (gdb_stdlog,
> >>>> +				"Process record: step.\n");
> >>>> +		  continue_flag = 0;
> >>>> +		}
> >>>>
> >>>> -			  continue_flag = 0;
> >>>> -			}
> >>>> +	      /* check breakpoint */
> >>>> +	      tmp_pc = regcache_read_pc (regcache);
> >>>> +	      if (record_check_stopped_by_breakpoint
> >>>> +		  (aspace, tmp_pc, &record_full_stop_reason))
> >>>> +		{
> >>>> +		  if (record_debug)
> >>>> +		    gdb_printf (gdb_stdlog,
> >>>> +				"Process record: break "
> >>>> +				"at %s.\n",
> >>>> +				paddress (gdbarch, tmp_pc));
> >>>>
> >>>> -		      if (record_full_stop_reason
> >>>> -			  == TARGET_STOPPED_BY_WATCHPOINT)
> >>>> -			{
> >>>> -			  if (record_debug)
> >>>> -			    gdb_printf (gdb_stdlog,
> >>>> -					"Process record: hit hw "
> >>>> -					"watchpoint.\n");
> >>>> -			  continue_flag = 0;
> >>>> -			}
> >>>> -		      /* Check target signal */
> >>>> -		      if (record_full_list->u.end.sigval != GDB_SIGNAL_0)
> >>>> -			/* FIXME: better way to check */
> >>>> -			continue_flag = 0;
> >>>> -		    }
> >>>> +		  continue_flag = 0;
> >>>>    		}
> >>>>
> >>>> -	      if (continue_flag)
> >>>> +	      if (record_full_stop_reason
> >>>> +		  == TARGET_STOPPED_BY_WATCHPOINT)
> >>>>    		{
> >>>> -		  if (execution_direction == EXEC_REVERSE)
> >>>> -		    {
> >>>> -		      if (record_full_list->prev)
> >>>> -			record_full_list = record_full_list->prev;
> >>>> -		    }
> >>>> -		  else
> >>>> -		    {
> >>>> -		      if (record_full_list->next)
> >>>> -			record_full_list = record_full_list->next;
> >>>> -		    }
> >>>> +		  if (record_debug)
> >>>> +		    gdb_printf (gdb_stdlog,
> >>>> +				"Process record: hit hw "
> >>>> +				"watchpoint.\n");
> >>>> +		  continue_flag = 0;
> >>>>    		}
> >>>> +	      if (record_full_list[record_full_next_insn].sigval.has_value ())
> >>>> +		continue_flag = 0;
> >>>> +
> >>>> +	      if (execution_direction == EXEC_REVERSE)
> >>>> +		record_full_next_insn--;
> >>>> +	      else
> >>>> +		record_full_next_insn++;
> >>>>    	    }
> >>>>    	  while (continue_flag);
> >>>>
> >>>> +	  if (record_full_next_insn < 0)
> >>>> +	    {
> >>>> +	      gdb_assert (execution_direction == EXEC_REVERSE);
> >>>> +	      record_full_next_insn = 0;
> >>>> +	    }
> >>>> +	  else if (record_full_next_insn > record_full_list.size ())
> >>>> +	    {
> >>>> +	      gdb_assert (execution_direction == EXEC_FORWARD);
> >>>> +	      record_full_next_insn = record_full_list.size ();
> >>>> +	    }
> >>>> +	  /* Reset the current instruciton to point to the one to be replayed
> >>> Nit: instruction
> >>>
> >>>> +	     moving forward.  */
> >>>> +	  else if (execution_direction == EXEC_REVERSE)
> >>>> +	    record_full_next_insn++;
> >>>> +
> >>>>    	replay_out:
> >>>>    	  if (status->kind () == TARGET_WAITKIND_STOPPED)
> >>>>    	    {
> >>>> +	      int insn = (execution_direction == EXEC_FORWARD)
> >>>> +			 ? record_full_next_insn - 1 : record_full_next_insn;
> >>>>    	      if (record_full_get_sig)
> >>>>    		status->set_stopped (GDB_SIGNAL_INT);
> >>>> -	      else if (record_full_list->u.end.sigval != GDB_SIGNAL_0)
> >>>> -		/* FIXME: better way to check */
> >>>> -		status->set_stopped (record_full_list->u.end.sigval);
> >>>> +	      else if (record_full_list[insn].sigval.has_value ())
> >>>> +		status->set_stopped
> >>>> +		  (record_full_list[insn].sigval.value ());
> >>>>    	      else
> >>>>    		status->set_stopped (GDB_SIGNAL_TRAP);
> >>>>    	    }
> >>>> @@ -1464,12 +1346,9 @@ record_full_wait_1 (struct target_ops *ops,
> >>>>          catch (const gdb_exception &ex)
> >>>>    	{
> >>>>    	  if (execution_direction == EXEC_REVERSE)
> >>>> -	    {
> >>>> -	      if (record_full_list->next)
> >>>> -		record_full_list = record_full_list->next;
> >>>> -	    }
> >>>> +	    record_full_next_insn++;
> >>>>    	  else
> >>>> -	    record_full_list = record_full_list->prev;
> >>>> +	    record_full_next_insn--;
> >>>>
> >>>>    	  throw;
> >>>>    	}
> >>>> @@ -1557,8 +1436,7 @@ record_full_registers_change (struct
> regcache
> >>>> *regcache, int regnum)
> >>>>      /* Check record_full_insn_num.  */
> >>>>      record_full_check_insn_num ();
> >>>>
> >>>> -  record_full_arch_list_head = NULL;
> >>>> -  record_full_arch_list_tail = NULL;
> >>>> +  record_full_reset_incomplete ();
> >>>>
> >>>>      if (regnum < 0)
> >>>>        {
> >>>> @@ -1568,7 +1446,7 @@ record_full_registers_change (struct
> regcache
> >>>> *regcache, int regnum)
> >>>>    	{
> >>>>    	  if (record_full_arch_list_add_reg (regcache, i))
> >>>>    	    {
> >>>> -	      record_full_list_release (record_full_arch_list_tail);
> >>>> +	      record_full_reset_incomplete ();
> >>>>    	      error (_("Process record: failed to record execution log."));
> >>>>    	    }
> >>>>    	}
> >>>> @@ -1577,18 +1455,11 @@ record_full_registers_change (struct
> >> regcache
> >>>> *regcache, int regnum)
> >>>>        {
> >>>>          if (record_full_arch_list_add_reg (regcache, regnum))
> >>>>    	{
> >>>> -	  record_full_list_release (record_full_arch_list_tail);
> >>>> +	  record_full_reset_incomplete ();
> >>>>    	  error (_("Process record: failed to record execution log."));
> >>>>    	}
> >>>>        }
> >>>> -  if (record_full_arch_list_add_end ())
> >>>> -    {
> >>>> -      record_full_list_release (record_full_arch_list_tail);
> >>>> -      error (_("Process record: failed to record execution log."));
> >>>> -    }
> >>>> -  record_full_list->next = record_full_arch_list_head;
> >>>> -  record_full_arch_list_head->prev = record_full_list;
> >>>> -  record_full_list = record_full_arch_list_tail;
> >>>> +  record_full_save_instruction ();
> >>>>
> >>>>      if (record_full_insn_num == record_full_insn_max_num)
> >>>>        record_full_list_release_first ();
> >>>> @@ -1607,7 +1478,7 @@ record_full_target::store_registers (struct
> >>>> regcache *regcache, int regno)
> >>>>    	{
> >>>>    	  int n;
> >>>>
> >>>> -	  /* Let user choose if he wants to write register or not.  */
> >>>> +	  /* Let user choose if they want to write register or not.  */
> >>>>    	  if (regno < 0)
> >>>>    	    n =
> >>>>    	      query (_("Because GDB is in replay mode, changing the "
> >>>> @@ -1642,7 +1513,7 @@ record_full_target::store_registers (struct
> >>>> regcache *regcache, int regno)
> >>>>    	    }
> >>>>
> >>>>    	  /* Destroy the record from here forward.  */
> >>>> -	  record_full_list_release_following (record_full_list);
> >>>> +	  record_full_list_release_following (record_full_next_insn);
> >>>>    	}
> >>>>
> >>>>          record_full_registers_change (regcache, regno);
> >>>> @@ -1675,36 +1546,24 @@ record_full_target::xfer_partial (enum
> >>>> target_object object,
> >>>>    	    error (_("Process record canceled the operation."));
> >>>>
> >>>>    	  /* Destroy the record from here forward.  */
> >>>> -	  record_full_list_release_following (record_full_list);
> >>>> +	  record_full_list_release_following (record_full_next_insn);
> >>>>    	}
> >>>>
> >>>>          /* Check record_full_insn_num */
> >>>>          record_full_check_insn_num ();
> >>>>
> >>>>          /* Record registers change to list as an instruction.  */
> >>>> -      record_full_arch_list_head = NULL;
> >>>> -      record_full_arch_list_tail = NULL;
> >>>> +      record_full_reset_incomplete ();
> >>>>          if (record_full_arch_list_add_mem (offset, len))
> >>>>    	{
> >>>> -	  record_full_list_release (record_full_arch_list_tail);
> >>>> +	  record_full_reset_incomplete ();
> >>>>    	  if (record_debug)
> >>>>    	    gdb_printf (gdb_stdlog,
> >>>>    			"Process record: failed to record "
> >>>>    			"execution log.");
> >>>>    	  return TARGET_XFER_E_IO;
> >>>>    	}
> >>>> -      if (record_full_arch_list_add_end ())
> >>>> -	{
> >>>> -	  record_full_list_release (record_full_arch_list_tail);
> >>>> -	  if (record_debug)
> >>>> -	    gdb_printf (gdb_stdlog,
> >>>> -			"Process record: failed to record "
> >>>> -			"execution log.");
> >>>> -	  return TARGET_XFER_E_IO;
> >>>> -	}
> >>>> -      record_full_list->next = record_full_arch_list_head;
> >>>> -      record_full_arch_list_head->prev = record_full_list;
> >>>> -      record_full_list = record_full_arch_list_tail;
> >>>> +      record_full_save_instruction ();
> >>>>
> >>>>          if (record_full_insn_num == record_full_insn_max_num)
> >>>>    	record_full_list_release_first ();
> >>>> @@ -1866,8 +1725,7 @@ record_full_base_target::get_bookmark
> (const
> >> char
> >>>> *args, int from_tty)
> >>>>      char *ret = NULL;
> >>>>
> >>>>      /* Return stringified form of instruction count.  */
> >>>> -  if (record_full_list && record_full_list->type == record_full_end)
> >>>> -    ret = xstrdup (pulongest (record_full_list->u.end.insn_num));
> >>>> +  ret = xstrdup (pulongest
> >> (record_full_list[record_full_next_insn].insn_num));
> >>> I think we can get here with an empty record_full_list - in case we are in
> >> recording mode,
> >>> no instructions have been logged and this function is called:
> >>>
> >>> ~~~
> >>> (gdb) info record
> >>> Active record target: record-full
> >>> Record mode:
> >>> No instructions have been logged.
> >>> Max logged instructions is 200000.
> >>> (gdb) bookmark
> >>>
> >>> Thread 1 "gdb-up" hit Breakpoint 1,
> record_full_base_target::get_bookmark
> >> (this=0x555558392900 <record_full_ops>, args=0x0, from_tty=1) at
> >> /tmp/record-full.c:1774
> >>> 1774      char *ret = NULL;
> >>> (gdb) p record_full_next_insn
> >>> $1 = 0
> >>> (gdb) p record_full_list.empty ()
> >>> $2 = true
> >>> ~~~
> > I wonder, do we somewhere have a test for bookmarks?
> > I also find a specific description for this in the manual... what's the
> difference to checkpoints?
> 
> Checkpoints fork the inferior and stop the fork immediately, allowing
> you to go back to that one point in time, but not executing backwards or
> anything, just changing forks and letting you see what things were like
> back then (that's why they won't work with multi-threaded programs).
> entirely unrelated to reverse debugging
> 
> Bookmarks let you mark one instruction in the history and easily go back
> to it using the reverse mechanism... at least that's what I've been able
> to get from the code, this predates me and I have no idea how it is
> actually used....
> 
> I quickly grep'd for bookmark tests and couldn't find any. We should
> probably add them at some point, if anyone even uses that feature......

Or at least adding some documentation, maybe more people would use it then ... 😉

Otherwise, if nobody uses it, we could deprecate and remove it at some point?
It just adds even more code to maintain...

> >
> > I am a bit confused about the bookmark feature (of course, this is nothing
> to fix for this series...).
> >
> >>>>      if (record_debug)
> >>>>        {
> >>>> @@ -1923,30 +1781,22 @@ record_full_base_target::record_method
> >> (ptid_t
> >>>> ptid)
> >>>>    void
> >>>>    record_full_base_target::info_record ()
> >>>>    {
> >>>> -  struct record_full_entry *p;
> >>>> -
> >>>>      if (RECORD_FULL_IS_REPLAY)
> >>>>        gdb_printf (_("Replay mode:\n"));
> >>>>      else
> >>>>        gdb_printf (_("Record mode:\n"));
> >>>>
> >>>> -  /* Find entry for first actual instruction in the log.  */
> >>>> -  for (p = record_full_first.next;
> >>>> -       p != NULL && p->type != record_full_end;
> >>>> -       p = p->next)
> >>>> -    ;
> >>>> -
> >>>>      /* Do we have a log at all?  */
> >>>> -  if (p != NULL && p->type == record_full_end)
> >>>> +  if (!record_full_list.empty ())
> >>>>        {
> >>>>          /* Display instruction number for first instruction in the log.  */
> >>>> -      gdb_printf (_("Lowest recorded instruction number is %s.\n"),
> >>>> -		  pulongest (p->u.end.insn_num));
> >>>> +      gdb_printf (_("Lowest recorded instruction number is %u.\n"),
> >>>> +		  record_full_list[0].insn_num);
> >>>>
> >>>>          /* If in replay mode, display where we are in the log.  */
> >>>>          if (RECORD_FULL_IS_REPLAY)
> >>>> -	gdb_printf (_("Current instruction number is %s.\n"),
> >>>> -		    pulongest (record_full_list->u.end.insn_num));
> >>>> +	gdb_printf (_("Current instruction number is %u.\n"),
> >>>> +		    record_full_list[record_full_next_insn].insn_num);
> >>>>
> >>>>          /* Display instruction number for last instruction in the log.  */
> >>>>          gdb_printf (_("Highest recorded instruction number is %s.\n"),
> >>>> @@ -1975,7 +1825,7 @@
> >> record_full_base_target::supports_delete_record ()
> >>>>    void
> >>>>    record_full_base_target::delete_record ()
> >>>>    {
> >>>> -  record_full_list_release_following (record_full_list);
> >>>> +  record_full_reset_history ();
> >>>>    }
> >>>>
> >>>>    /* The "record_is_replaying" target method.  */
> >>>> @@ -2001,23 +1851,23 @@
> record_full_base_target::record_will_replay
> >>>> (ptid_t ptid, int dir)
> >>>>    /* Go to a specific entry.  */
> >>>>
> >>>>    static void
> >>>> -record_full_goto_entry (struct record_full_entry *p)
> >>>> +record_full_goto_entry (size_t target_insn)
> >>>>    {
> >>>> -  if (p == NULL)
> >>>> +  if (target_insn >= record_full_list.size ())
> >>>>        error (_("Target insn not found."));
> >>>> -  else if (p == record_full_list)
> >>>> +  else if (target_insn == record_full_next_insn)
> >>>>        error (_("Already at target insn."));
> >>>> -  else if (p->u.end.insn_num > record_full_list->u.end.insn_num)
> >>>> +  else if (target_insn > record_full_next_insn)
> >>>>        {
> >>>>          gdb_printf (_("Go forward to insn number %s\n"),
> >>>> -		  pulongest (p->u.end.insn_num));
> >>>> -      record_full_goto_insn (p, EXEC_FORWARD);
> >>>> +		  pulongest (record_full_list[target_insn].insn_num));
> >>>> +      record_full_goto_insn (target_insn, EXEC_FORWARD);
> >>>>        }
> >>>>      else
> >>>>        {
> >>>>          gdb_printf (_("Go backward to insn number %s\n"),
> >>>> -		  pulongest (p->u.end.insn_num));
> >>>> -      record_full_goto_insn (p, EXEC_REVERSE);
> >>>> +		  pulongest (target_insn));
> >>>> +      record_full_goto_insn (target_insn, EXEC_REVERSE);
> >>>>        }
> >>>>
> >>>>      registers_changed ();
> >>>> @@ -2033,13 +1883,7 @@ record_full_goto_entry (struct
> >> record_full_entry
> >>>> *p)
> >>>>    void
> >>>>    record_full_base_target::goto_record_begin ()
> >>>>    {
> >>>> -  struct record_full_entry *p = NULL;
> >>>> -
> >>>> -  for (p = &record_full_first; p != NULL; p = p->next)
> >>>> -    if (p->type == record_full_end)
> >>>> -      break;
> >>>> -
> >>>> -  record_full_goto_entry (p);
> >>>> +  record_full_goto_entry (0);
> >>>>    }
> >>>>
> >>>>    /* The "goto_record_end" target method.  */
> >>>> @@ -2047,15 +1891,7 @@
> record_full_base_target::goto_record_begin ()
> >>>>    void
> >>>>    record_full_base_target::goto_record_end ()
> >>>>    {
> >>>> -  struct record_full_entry *p = NULL;
> >>>> -
> >>>> -  for (p = record_full_list; p->next != NULL; p = p->next)
> >>>> -    ;
> >>>> -  for (; p!= NULL; p = p->prev)
> >>>> -    if (p->type == record_full_end)
> >>>> -      break;
> >>>> -
> >>>> -  record_full_goto_entry (p);
> >>>> +  record_full_goto_entry (record_full_list.size () -1);
> >>> Nit: whitespace before 1 => "record_full_list.size () - 1"
> >>>
> >>> And in case the record_full_list is empty, won't we call
> >>> record_full_goto_entry with an invalid value for target_insn ?
> >>>
> >>>>    }
> >>>>
> >>>>    /* The "goto_record" target method.  */
> >>>> @@ -2063,13 +1899,7 @@ record_full_base_target::goto_record_end
> ()
> >>>>    void
> >>>>    record_full_base_target::goto_record (ULONGEST target_insn)
> >>>>    {
> >>>> -  struct record_full_entry *p = NULL;
> >>>> -
> >>>> -  for (p = &record_full_first; p != NULL; p = p->next)
> >>>> -    if (p->type == record_full_end && p->u.end.insn_num == target_insn)
> >>>> -      break;
> >>>> -
> >>>> -  record_full_goto_entry (p);
> >>>> +  record_full_goto_entry (target_insn);
> >>>>    }
> >>>>
> >>>>    /* The "record_stop_replaying" target method.  */
> >>>> @@ -2339,19 +2169,96 @@ netorder32 (uint32_t input)
> >>>>      return ret;
> >>>>    }
> >>>>
> >>>> +static void
> >>>> +record_full_read_entry_from_bfd (bfd *cbfd, asection *osec, int
> >> *bfd_offset)
> >>>> +{
> >>>> +  uint8_t rectype;
> >>>> +  uint32_t regnum, len;
> >>>> +  uint64_t addr;
> >>>> +  regcache *cache = get_thread_regcache (inferior_thread ());
> >>>> +
> >>>> +  bfdcore_read (cbfd, osec, &rectype, sizeof (rectype), bfd_offset);
> >>>> +  switch (rectype)
> >>>> +    {
> >>>> +    case record_full_reg: /* reg */
> >>>> +      {
> >>>> +	/* Get register number to regnum.  */
> >>>> +	bfdcore_read (cbfd, osec, &regnum, sizeof (regnum), bfd_offset);
> >>>> +	regnum = netorder32 (regnum);
> >>>> +
> >>>> +	record_full_entry rec;
> >>>> +
> >>>> +	rec = record_full_reg_init (cache, regnum);
> >>>> +
> >>>> +	/* Get val.  */
> >>>> +	bfdcore_read (cbfd, osec, record_full_get_loc (&rec),
> >>>> +		      rec.u.reg.len, bfd_offset);
> >>>> +
> >>>> +	if (record_debug)
> >>>> +	  gdb_printf (gdb_stdlog,
> >>>> +		      "  Reading register %d (1 "
> >>>> +		      "plus %lu plus %d bytes)\n",
> >>>> +		      rec.u.reg.num,
> >>>> +		      (unsigned long) sizeof (regnum),
> >>>> +		      rec.u.reg.len);
> >>>> +
> >>>> +	record_full_arch_list_add (rec);
> >>>> +	break;
> >>>> +      }
> >>>> +
> >>>> +    case record_full_mem: /* mem */
> >>>> +      {
> >>>> +	/* Get len.  */
> >>>> +	bfdcore_read (cbfd, osec, &len, sizeof (len), bfd_offset);
> >>>> +	len = netorder32 (len);
> >>>> +
> >>>> +	/* Get addr.  */
> >>>> +	bfdcore_read (cbfd, osec, &addr, sizeof (addr),
> >>>> +		      bfd_offset);
> >>>> +	addr = netorder64 (addr);
> >>>> +
> >>>> +	record_full_entry rec;
> >>>> +	rec = record_full_mem_init (addr, len);
> >>>> +
> >>>> +	/* Get val.  */
> >>>> +	bfdcore_read (cbfd, osec, record_full_get_loc (&rec), len,
> >>>> +		      bfd_offset);
> >>>> +
> >>>> +	if (record_debug)
> >>>> +	  gdb_printf (gdb_stdlog,
> >>>> +		      "  Reading memory %s (1 plus "
> >>>> +		      "%lu plus %lu plus %d bytes)\n",
> >>>> +		      paddress (get_current_arch (),
> >>>> +				rec.u.mem.addr),
> >>>> +		      (unsigned long) sizeof (addr),
> >>>> +		      (unsigned long) sizeof (len),
> >>>> +		      len);
> >>>> +
> >>>> +	record_full_arch_list_add (rec);
> >>>> +	break;
> >>>> +      }
> >>>> +
> >>>> +    default:
> >>>> +      error (_("Bad entry type %d, offset %d of %lu in core file %ps."),
> >>>> +	     rectype, *bfd_offset, bfd_section_size (osec),
> >>>> +	     styled_string (file_name_style.style (),
> >>>> +			    bfd_get_filename (cbfd)));
> >>>> +      break;
> >>>> +    }
> >>>> +}
> >>>> +
> >>>>    /* Restore the execution log from core file CBFD.  */
> >>>>
> >>>>    static void
> >>>>    record_full_restore (struct bfd &cbfd)
> >>>>    {
> >>>>      uint32_t magic;
> >>>> -  struct record_full_entry *rec;
> >>>>      asection *osec;
> >>>>      uint32_t osec_size;
> >>>>      int bfd_offset = 0;
> >>>>
> >>>>      /* "record_full_restore" can only be called when record list is empty.
> */
> >>>> -  gdb_assert (record_full_first.next == NULL);
> >>>> +  gdb_assert (record_full_list.empty ());
> >>>>
> >>>>      if (record_debug)
> >>>>        gdb_printf (gdb_stdlog, "Restoring recording from core file.\n");
> >>>> @@ -2379,124 +2286,47 @@ record_full_restore (struct bfd &cbfd)
> >>>>    		"RECORD_FULL_FILE_MAGIC (0x%s)\n",
> >>>>    		phex_nz (netorder32 (magic), 4));
> >>>>
> >>>> -  /* Restore the entries in recfd into record_full_arch_list_head and
> >>>> -     record_full_arch_list_tail.  */
> >>>> -  record_full_arch_list_head = NULL;
> >>>> -  record_full_arch_list_tail = NULL;
> >>>>      record_full_insn_num = 0;
> >>>>
> >>>>      try
> >>>>        {
> >>>> -      regcache *regcache = get_thread_regcache (inferior_thread ());
> >>>> -
> >>>> -      while (1)
> >>>> +      while (bfd_offset < osec_size)
> >>>>    	{
> >>>> -	  uint8_t rectype;
> >>>> -	  uint32_t regnum, len, signal, count;
> >>>> -	  uint64_t addr;
> >>>> -
> >>>> -	  /* We are finished when offset reaches osec_size.  */
> >>>> -	  if (bfd_offset >= osec_size)
> >>>> -	    break;
> >>>> -	  bfdcore_read (&cbfd, osec, &rectype, sizeof (rectype), &bfd_offset);
> >>>> -
> >>>> -	  switch (rectype)
> >>>> +	  record_full_reset_incomplete ();
> >>>> +	  uint32_t eff_count = 0;
> >>>> +	  uint8_t sigval;
> >>>> +	  uint32_t insn_num;
> >>>> +
> >>>> +	  /* First read the generic information for an instruction.  */
> >>>> +	  bfdcore_read (&cbfd, osec, &sigval, sizeof (uint8_t), &bfd_offset);
> >>>> +	  bfdcore_read (&cbfd, osec, &eff_count, sizeof (uint32_t),
> >>>> +			&bfd_offset);
> >>>> +	  bfdcore_read (&cbfd, osec, &insn_num, sizeof (uint32_t),
> >>>> +			&bfd_offset);
> >>>> +
> >>>> +	  record_full_incomplete_instruction.insn_num = netorder32
> >>>> (insn_num);
> >>>> +	  if (sigval != GDB_SIGNAL_0)
> >>>> +	    record_full_incomplete_instruction.sigval = (gdb_signal) sigval;
> >>>> +
> >>>> +	  eff_count = netorder32 (eff_count);
> >>>> +
> >>>> +	  /* This deals with all the side effects.  */
> >>>> +	 while (eff_count > 0)
> >>>>    	    {
> >>> There is one space too much indent.
> >>>
> >>>> -	    case record_full_reg: /* reg */
> >>>> -	      /* Get register number to regnum.  */
> >>>> -	      bfdcore_read (&cbfd, osec, &regnum, sizeof (regnum),
> >>>> -			    &bfd_offset);
> >>>> -	      regnum = netorder32 (regnum);
> >>>> -
> >>>> -	      rec = record_full_reg_alloc (regcache, regnum);
> >>>> -
> >>>> -	      /* Get val.  */
> >>>> -	      bfdcore_read (&cbfd, osec, record_full_get_loc (rec),
> >>>> -			    rec->u.reg.len, &bfd_offset);
> >>>> -
> >>>> -	      if (record_debug)
> >>>> -		gdb_printf (gdb_stdlog,
> >>>> -			    "  Reading register %d (1 "
> >>>> -			    "plus %lu plus %d bytes)\n",
> >>>> -			    rec->u.reg.num,
> >>>> -			    (unsigned long) sizeof (regnum),
> >>>> -			    rec->u.reg.len);
> >>>> -	      break;
> >>>> +	      eff_count--;
> >>>>
> >>>> -	    case record_full_mem: /* mem */
> >>>> -	      /* Get len.  */
> >>>> -	      bfdcore_read (&cbfd, osec, &len, sizeof (len), &bfd_offset);
> >>>> -	      len = netorder32 (len);
> >>>> -
> >>>> -	      /* Get addr.  */
> >>>> -	      bfdcore_read (&cbfd, osec, &addr, sizeof (addr), &bfd_offset);
> >>>> -	      addr = netorder64 (addr);
> >>>> -
> >>>> -	      rec = record_full_mem_alloc (addr, len);
> >>>> -
> >>>> -	      /* Get val.  */
> >>>> -	      bfdcore_read (&cbfd, osec, record_full_get_loc (rec),
> >>>> -			    rec->u.mem.len, &bfd_offset);
> >>>> -
> >>>> -	      if (record_debug)
> >>>> -		gdb_printf (gdb_stdlog,
> >>>> -			    "  Reading memory %s (1 plus "
> >>>> -			    "%lu plus %lu plus %d bytes)\n",
> >>>> -			    paddress (get_current_arch (),
> >>>> -				      rec->u.mem.addr),
> >>>> -			    (unsigned long) sizeof (addr),
> >>>> -			    (unsigned long) sizeof (len),
> >>>> -			    rec->u.mem.len);
> >>>> -	      break;
> >>>> -
> >>>> -	    case record_full_end: /* end */
> >>>> -	      rec = record_full_end_alloc ();
> >>>> -	      record_full_insn_num ++;
> >>>> -
> >>>> -	      /* Get signal value.  */
> >>>> -	      bfdcore_read (&cbfd, osec, &signal, sizeof (signal),
> >>>> -			    &bfd_offset);
> >>>> -	      signal = netorder32 (signal);
> >>>> -	      rec->u.end.sigval = (enum gdb_signal) signal;
> >>>> -
> >>>> -	      /* Get insn count.  */
> >>>> -	      bfdcore_read (&cbfd, osec, &count, sizeof (count), &bfd_offset);
> >>>> -	      count = netorder32 (count);
> >>>> -	      rec->u.end.insn_num = count;
> >>>> -	      record_full_insn_count = count + 1;
> >>>> -	      if (record_debug)
> >>>> -		gdb_printf (gdb_stdlog,
> >>>> -			    "  Reading record_full_end (1 + "
> >>>> -			    "%lu + %lu bytes), offset == %s\n",
> >>>> -			    (unsigned long) sizeof (signal),
> >>>> -			    (unsigned long) sizeof (count),
> >>>> -			    paddress (get_current_arch (),
> >>>> -				      bfd_offset));
> >>>> -	      break;
> >>>> -
> >>>> -	    default:
> >>>> -	      error (_("Bad entry type in core file %ps."),
> >>>> -		     styled_string (file_name_style.style (),
> >>>> -				    bfd_get_filename (&cbfd)));
> >>>> -	      break;
> >>>> +	      record_full_read_entry_from_bfd (&cbfd, osec, &bfd_offset);
> >>>>    	    }
> >>>>
> >>>> -	  /* Add rec to record arch list.  */
> >>>> -	  record_full_arch_list_add (rec);
> >>>> +	  record_full_save_instruction ();
> >>>>    	}
> >>>>        }
> >>>>      catch (const gdb_exception &ex)
> >>>>        {
> >>>> -      record_full_list_release (record_full_arch_list_tail);
> >>>> +      record_full_reset_incomplete ();
> >>>>          throw;
> >>>>        }
> >>>>
> >>>> -  /* Add record_full_arch_list_head to the end of record list.  */
> >>>> -  record_full_first.next = record_full_arch_list_head;
> >>>> -  record_full_arch_list_head->prev = &record_full_first;
> >>>> -  record_full_arch_list_tail->next = NULL;
> >>>> -  record_full_list = &record_full_first;
> >>>> -
> >>>>      /* Update record_full_insn_max_num.  */
> >>>>      if (record_full_insn_num > record_full_insn_max_num)
> >>>>        {
> >>>> @@ -2505,6 +2335,10 @@ record_full_restore (struct bfd &cbfd)
> >>>>    	       record_full_insn_max_num);
> >>>>        }
> >>>>
> >>>> +  /* When loading a recording, we'll always start at the oldest possible
> >>>> +     instruction, no matter where the original recording was stopped.  */
> >>>> +  record_full_next_insn = 0;
> >>>> +
> >>>>      /* Succeeded.  */
> >>>>      gdb_printf (_("Restored records from core file %s.\n"),
> >>>>    	      bfd_get_filename (&cbfd));
> >>>> @@ -2538,13 +2372,73 @@ cmd_record_full_restore (const char
> *args,
> >> int
> >>>> from_tty)
> >>>>      record_full_open (nullptr, from_tty);
> >>>>    }
> >>>>
> >>>> +static void
> >>>> +record_full_write_entry_to_bfd (record_full_entry &entry,
> >>>> +				gdb_bfd_ref_ptr obfd,
> >>>> +				asection *osec, int *bfd_offset,
> >>>> +				struct gdbarch *gdbarch)
> >>>> +{
> >>>> +  /* Save entry.  */
> >>>> +  uint8_t type;
> >>>> +  uint32_t regnum, len;
> >>>> +  uint64_t addr;
> >>>> +
> >>>> +  type = entry.type;
> >>>> +  bfdcore_write (obfd.get (), osec, &type, sizeof (type), bfd_offset);
> >>>> +
> >>>> +  switch (entry.type)
> >>>> +    {
> >>>> +    case record_full_reg: /* reg */
> >>>> +      if (record_debug)
> >>>> +	gdb_printf (gdb_stdlog,
> >>>> +		    "  Writing register %d (1 "
> >>>> +		    "plus %lu plus %d bytes)\n",
> >>>> +		    entry.u.reg.num,
> >>>> +		    (unsigned long) sizeof (regnum),
> >>>> +		    entry.u.reg.len);
> >>>> +
> >>>> +      /* Write regnum.  */
> >>>> +      regnum = netorder32 (entry.u.reg.num);
> >>>> +      bfdcore_write (obfd.get (), osec, &regnum, sizeof (regnum),
> >> bfd_offset);
> >>>> +
> >>>> +      /* Write regval.  */
> >>>> +      bfdcore_write (obfd.get (), osec, record_full_get_loc (&entry),
> >>>> +		     entry.u.reg.len, bfd_offset);
> >>>> +      break;
> >>>> +
> >>>> +    case record_full_mem: /* mem */
> >>>> +      if (record_debug)
> >>>> +	gdb_printf (gdb_stdlog,
> >>>> +		    "  Writing memory %s (1 plus "
> >>>> +		    "%lu plus %lu plus %d bytes)\n",
> >>>> +		    paddress (gdbarch,
> >>>> +			      entry.u.mem.addr),
> >>>> +		    (unsigned long) sizeof (addr),
> >>>> +		    (unsigned long) sizeof (len),
> >>>> +		    entry.u.mem.len);
> >>>> +
> >>>> +      /* Write memlen.  */
> >>>> +      len = netorder32 (entry.u.mem.len);
> >>>> +      bfdcore_write (obfd.get (), osec, &len, sizeof (len), bfd_offset);
> >>>> +
> >>>> +      /* Write memaddr.  */
> >>>> +      addr = netorder64 (entry.u.mem.addr);
> >>>> +      bfdcore_write (obfd.get (), osec, &addr, sizeof (addr), bfd_offset);
> >>>> +
> >>>> +      /* Write memval.  */
> >>>> +      bfdcore_write (obfd.get (), osec, record_full_get_loc (&entry),
> >>>> +		     entry.u.mem.len, bfd_offset);
> >>>> +      break;
> >>>> +    }
> >>>> +
> >>>> +}
> >>>> +
> >>>>    /* Save the execution log to a file.  We use a modified elf corefile
> >>>>       format, with an extra section for our data.  */
> >>>>
> >>>>    void
> >>>>    record_full_base_target::save_record (const char *recfilename)
> >>>>    {
> >>>> -  struct record_full_entry *cur_record_full_list;
> >>>>      uint32_t magic;
> >>>>      struct gdbarch *gdbarch;
> >>>>      int save_size = 0;
> >>>> @@ -2562,9 +2456,6 @@ record_full_base_target::save_record (const
> >> char
> >>>> *recfilename)
> >>>>      /* Arrange to remove the output file on failure.  */
> >>>>      gdb::unlinker unlink_file (recfilename);
> >>>>
> >>>> -  /* Save the current record entry to "cur_record_full_list".  */
> >>>> -  cur_record_full_list = record_full_list;
> >>>> -
> >>>>      /* Get the values of regcache and gdbarch.  */
> >>>>      regcache *regcache = get_thread_regcache (inferior_thread ());
> >>>>      gdbarch = regcache->arch ();
> >>>> @@ -2574,34 +2465,27 @@ record_full_base_target::save_record
> (const
> >>>> char *recfilename)
> >>>>        = record_full_gdb_operation_disable_set ();
> >>>>
> >>>>      /* Reverse execute to the begin of record list.  */
> >>>> -  while (1)
> >>>> -    {
> >>>> -      /* Check for beginning and end of log.  */
> >>>> -      if (record_full_list == &record_full_first)
> >>>> -	break;
> >>>> -
> >>>> -      record_full_exec_insn (regcache, gdbarch, record_full_list);
> >>>> -
> >>>> -      if (record_full_list->prev)
> >>>> -	record_full_list = record_full_list->prev;
> >>>> -    }
> >>>> +  for (int i = record_full_next_insn - 1; i >= 0; i--)
> >>>> +    record_full_exec_insn (regcache, gdbarch,
> >>>> +			   record_full_list[i]);
> >>>>
> >>>>      /* Compute the size needed for the extra bfd section.  */
> >>>>      save_size = 4;	/* magic cookie */
> >>>> -  for (record_full_list = record_full_first.next; record_full_list;
> >>>> -       record_full_list = record_full_list->next)
> >>>> -    switch (record_full_list->type)
> >>>> -      {
> >>>> -      case record_full_end:
> >>>> -	save_size += 1 + 4 + 4;
> >>>> -	break;
> >>>> -      case record_full_reg:
> >>>> -	save_size += 1 + 4 + record_full_list->u.reg.len;
> >>>> -	break;
> >>>> -      case record_full_mem:
> >>>> -	save_size += 1 + 4 + 8 + record_full_list->u.mem.len;
> >>>> -	break;
> >>>> -      }
> >>>> +  for (int i = record_full_list.size () - 1; i >= 0; i--)
> >>>> +    {
> >>>> +      /* Number of effects of an instruction.  */
> >>>> +      save_size += sizeof (uint32_t) + sizeof (uint8_t) + sizeof (uint32_t);
> >>>> +      for (auto &entry : record_full_list[i].effects)
> >>>> +	switch (entry.type)
> >>>> +	  {
> >>>> +	  case record_full_reg:
> >>>> +	    save_size += 1 + 4 + entry.u.reg.len;
> >>>> +	    break;
> >>>> +	  case record_full_mem:
> >>>> +	    save_size += 1 + 4 + 8 + entry.u.mem.len;
> >>>> +	    break;
> >>>> +	  }
> >>>> +    }
> >>>>
> >>>>      /* Make the new bfd section.  */
> >>>>      osec = bfd_make_section_anyway_with_flags (obfd.get (), "precord",
> >>>> @@ -2630,108 +2514,32 @@ record_full_base_target::save_record
> >> (const
> >>>> char *recfilename)
> >>>>
> >>>>      /* Save the entries to recfd and forward execute to the end of
> >>>>         record list.  */
> >>>> -  record_full_list = &record_full_first;
> >>>> -  while (1)
> >>>> +  for (int i = 0; i < record_full_list.size (); i++)
> >>>>        {
> >>>> -      /* Save entry.  */
> >>>> -      if (record_full_list != &record_full_first)
> >>>> +      uint32_t eff_count = (uint32_t) record_full_list[i].effects.size ();
> >>>> +      uint32_t insn_num = record_full_list[i].insn_num;
> >>>> +      uint8_t sigval = (record_full_list[i].sigval.has_value ())
> >>>> +			 ? record_full_list[i].sigval.value ()
> >>>> +			 : GDB_SIGNAL_0;
> >>>> +
> >>>> +      /* Signal.  */
> >>>> +      bfdcore_write (obfd.get (), osec, &sigval, sizeof (sigval),
> &bfd_offset);
> >>>> +      eff_count = netorder32 (eff_count);
> >>>> +      /* Number of effects.  */
> >>>> +      bfdcore_write (obfd.get (), osec, &eff_count, sizeof (eff_count),
> >>>> +		     &bfd_offset);
> >>>> +      /* Instruction number.  */
> >>>> +      bfdcore_write (obfd.get (), osec, &insn_num, sizeof (uint32_t),
> >>>> +		     &bfd_offset);
> >>>> +
> >>>> +      for (auto &entry : record_full_list[i].effects)
> >>>>    	{
> >>>> -	  uint8_t type;
> >>>> -	  uint32_t regnum, len, signal, count;
> >>>> -	  uint64_t addr;
> >>>> -
> >>>> -	  type = record_full_list->type;
> >>>> -	  bfdcore_write (obfd.get (), osec, &type, sizeof (type), &bfd_offset);
> >>>> -
> >>>> -	  switch (record_full_list->type)
> >>>> -	    {
> >>>> -	    case record_full_reg: /* reg */
> >>>> -	      if (record_debug)
> >>>> -		gdb_printf (gdb_stdlog,
> >>>> -			    "  Writing register %d (1 "
> >>>> -			    "plus %lu plus %d bytes)\n",
> >>>> -			    record_full_list->u.reg.num,
> >>>> -			    (unsigned long) sizeof (regnum),
> >>>> -			    record_full_list->u.reg.len);
> >>>> -
> >>>> -	      /* Write regnum.  */
> >>>> -	      regnum = netorder32 (record_full_list->u.reg.num);
> >>>> -	      bfdcore_write (obfd.get (), osec, &regnum,
> >>>> -			     sizeof (regnum), &bfd_offset);
> >>>> -
> >>>> -	      /* Write regval.  */
> >>>> -	      bfdcore_write (obfd.get (), osec,
> >>>> -			     record_full_get_loc (record_full_list),
> >>>> -			     record_full_list->u.reg.len, &bfd_offset);
> >>>> -	      break;
> >>>> -
> >>>> -	    case record_full_mem: /* mem */
> >>>> -	      if (record_debug)
> >>>> -		gdb_printf (gdb_stdlog,
> >>>> -			    "  Writing memory %s (1 plus "
> >>>> -			    "%lu plus %lu plus %d bytes)\n",
> >>>> -			    paddress (gdbarch,
> >>>> -				      record_full_list->u.mem.addr),
> >>>> -			    (unsigned long) sizeof (addr),
> >>>> -			    (unsigned long) sizeof (len),
> >>>> -			    record_full_list->u.mem.len);
> >>>> -
> >>>> -	      /* Write memlen.  */
> >>>> -	      len = netorder32 (record_full_list->u.mem.len);
> >>>> -	      bfdcore_write (obfd.get (), osec, &len, sizeof (len),
> >>>> -			     &bfd_offset);
> >>>> -
> >>>> -	      /* Write memaddr.  */
> >>>> -	      addr = netorder64 (record_full_list->u.mem.addr);
> >>>> -	      bfdcore_write (obfd.get (), osec, &addr,
> >>>> -			     sizeof (addr), &bfd_offset);
> >>>> -
> >>>> -	      /* Write memval.  */
> >>>> -	      bfdcore_write (obfd.get (), osec,
> >>>> -			     record_full_get_loc (record_full_list),
> >>>> -			     record_full_list->u.mem.len, &bfd_offset);
> >>>> -	      break;
> >>>> -
> >>>> -	      case record_full_end:
> >>>> -		if (record_debug)
> >>>> -		  gdb_printf (gdb_stdlog,
> >>>> -			      "  Writing record_full_end (1 + "
> >>>> -			      "%lu + %lu bytes)\n",
> >>>> -			      (unsigned long) sizeof (signal),
> >>>> -			      (unsigned long) sizeof (count));
> >>>> -		/* Write signal value.  */
> >>>> -		signal = netorder32 (record_full_list->u.end.sigval);
> >>>> -		bfdcore_write (obfd.get (), osec, &signal,
> >>>> -			       sizeof (signal), &bfd_offset);
> >>>> -
> >>>> -		/* Write insn count.  */
> >>>> -		count = netorder32 (record_full_list->u.end.insn_num);
> >>>> -		bfdcore_write (obfd.get (), osec, &count,
> >>>> -			       sizeof (count), &bfd_offset);
> >>>> -		break;
> >>>> -	    }
> >>>> +	  record_full_write_entry_to_bfd (entry, obfd, osec, &bfd_offset,
> >>>> +					  gdbarch);
> >>>>    	}
> >>>> -
> >>>>          /* Execute entry.  */
> >>>> -      record_full_exec_insn (regcache, gdbarch, record_full_list);
> >>>> -
> >>>> -      if (record_full_list->next)
> >>>> -	record_full_list = record_full_list->next;
> >>>> -      else
> >>>> -	break;
> >>>> -    }
> >>>> -
> >>>> -  /* Reverse execute to cur_record_full_list.  */
> >>>> -  while (1)
> >>>> -    {
> >>>> -      /* Check for beginning and end of log.  */
> >>>> -      if (record_full_list == cur_record_full_list)
> >>>> -	break;
> >>>> -
> >>>> -      record_full_exec_insn (regcache, gdbarch, record_full_list);
> >>>> -
> >>>> -      if (record_full_list->prev)
> >>>> -	record_full_list = record_full_list->prev;
> >>>> +      if (i < record_full_next_insn)
> >>>> +	record_full_exec_insn (regcache, gdbarch, record_full_list[i]);
> >>>>        }
> >>>>
> >>>>      unlink_file.keep ();
> >>>> @@ -2746,7 +2554,7 @@ record_full_base_target::save_record (const
> >> char
> >>>> *recfilename)
> >>>>       correspondingly.  */
> >>>>
> >>>>    static void
> >>>> -record_full_goto_insn (struct record_full_entry *entry,
> >>>> +record_full_goto_insn (size_t target_insn,
> >>>>    		       enum exec_direction_kind dir)
> >>> You could explain the new parameter in the function description.
> >>>
> >>>>    {
> >>>>      scoped_restore restore_operation_disable
> >>>> @@ -2757,17 +2565,12 @@ record_full_goto_insn (struct
> >> record_full_entry
> >>>> *entry,
> >>>>      /* Assume everything is valid: we will hit the entry,
> >>>>         and we will not hit the end of the recording.  */
> >>>>
> >>>> -  if (dir == EXEC_FORWARD)
> >>>> -    record_full_list = record_full_list->next;
> >>>> -
> >>>> -  do
> >>>> -    {
> >>>> -      record_full_exec_insn (regcache, gdbarch, record_full_list);
> >>>> -      if (dir == EXEC_REVERSE)
> >>>> -	record_full_list = record_full_list->prev;
> >>>> -      else
> >>>> -	record_full_list = record_full_list->next;
> >>>> -    } while (record_full_list != entry);
> >>>> +  if (dir == EXEC_REVERSE)
> >>>> +    for (int i = record_full_next_insn; i > target_insn; i--)
> >>>> +      record_full_exec_insn (regcache, gdbarch, record_full_list[i - 1]);
> >>>> +  else
> >>>> +    for (int i = record_full_next_insn; i < target_insn; i++)
> >>>> +      record_full_exec_insn (regcache, gdbarch, record_full_list[i]);
> >>>>    }
> >>>>
> >>>>    /* Alias for "target record-full".  */
> >>>> @@ -2798,61 +2601,36 @@ set_record_full_insn_max_num (const
> char
> >>>> *args, int from_tty,
> >>>>    static void
> >>>>    maintenance_print_record_instruction (const char *args, int from_tty)
> >>>>    {
> >>>> -  struct record_full_entry *to_print = record_full_list;
> >>>> +  if (record_full_list.empty ())
> >>>> +    error (_("Not enough recorded history"));
> >>>>
> >>>> +  int offset = record_full_next_insn - 1;
> >>>> +  /* Reduce the offset by 1 if the record_full_next_insn is after the end
> >>>> +     so that we show the last recorded instruction instead of crashing.
> */
> >>>> +  if (offset == record_full_list.size ())
> >>>> +    offset--;
> >>>>      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"));
> >>>> -	}
> >>>> +      offset += value_as_long (parse_and_eval (args));
> >>>> +      if (offset >= record_full_list.size () || offset < 0)
> >>>> +	error (_("Not enough recorded history"));
> >>>>        }
> >>>> -  gdb_assert (to_print != nullptr);
> >>>> +  auto to_print = record_full_list.begin () + offset;
> >>>>
> >>>>      gdbarch *arch = current_inferior ()->arch ();
> >>>>
> >>>> -  /* 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)
> >>>> +  for (auto entry : to_print->effects)
> >>>>        {
> >>>> -      switch (to_print->type)
> >>>> +      switch (entry.type)
> >>>>    	{
> >>>>    	  case record_full_reg:
> >>>>    	    {
> >>>> -	      type *regtype = gdbarch_register_type (arch, to_print-
> >>>>> u.reg.num);
> >>>> +	      type *regtype = gdbarch_register_type (arch, entry.u.reg.num);
> >>>>    	      value *val
> >>>>    		  = value_from_contents (regtype,
> >>>> -					 record_full_get_loc (to_print));
> >>>> +					 record_full_get_loc (&entry));
> >>>>    	      gdb_printf ("Register %s changed: ",
> >>>> -			  gdbarch_register_name (arch, to_print-
> >>>>> u.reg.num));
> >>>> +			  gdbarch_register_name (arch, entry.u.reg.num));
> >>>>    	      struct value_print_options opts;
> >>>>    	      get_user_print_options (&opts);
> >>>>    	      opts.raw = true;
> >>>> @@ -2862,17 +2640,16 @@ maintenance_print_record_instruction
> >> (const
> >>>> char *args, int from_tty)
> >>>>    	    }
> >>>>    	  case record_full_mem:
> >>>>    	    {
> >>>> -	      gdb_byte *b = record_full_get_loc (to_print);
> >>>> +	      gdb_byte *b = record_full_get_loc (&entry);
> >>>>    	      gdb_printf ("%d bytes of memory at address %s changed from:",
> >>>> -			  to_print->u.mem.len,
> >>>> -			  print_core_address (arch, to_print->u.mem.addr));
> >>>> -	      for (int i = 0; i < to_print->u.mem.len; i++)
> >>>> +			  entry.u.mem.len,
> >>>> +			  print_core_address (arch, entry.u.mem.addr));
> >>>> +	      for (int i = 0; i < entry.u.mem.len; i++)
> >>>>    		gdb_printf (" %02x", b[i]);
> >>>>    	      gdb_printf ("\n");
> >>>>    	      break;
> >>>>    	    }
> >>>>    	}
> >>>> -      to_print = to_print->next;
> >>>>        }
> >>>>    }
> >>>>
> >>>> @@ -2880,11 +2657,6 @@ INIT_GDB_FILE (record_full)
> >>>>    {
> >>>>      struct cmd_list_element *c;
> >>>>
> >>>> -  /* Init record_full_first.  */
> >>>> -  record_full_first.prev = NULL;
> >>>> -  record_full_first.next = NULL;
> >>>> -  record_full_first.type = record_full_end;
> >>>> -
> >>>>      add_target (record_full_target_info, record_full_open);
> >>>>      add_deprecated_target_alias (record_full_target_info, "record");
> >>>>      add_target (record_full_core_target_info, record_full_open);
> >>>> diff --git a/gdb/record-full.h b/gdb/record-full.h
> >>>> index 51effe74560..c327d879a8a 100644
> >>>> --- a/gdb/record-full.h
> >>>> +++ b/gdb/record-full.h
> >>>> @@ -41,7 +41,6 @@ enum record_result
> >>>>
> >>>>    extern int record_full_arch_list_add_reg (struct regcache *regcache,
> int
> >>>> num);
> >>>>    extern int record_full_arch_list_add_mem (CORE_ADDR addr, int len);
> >>>> -extern int record_full_arch_list_add_end (void);
> >>>>
> >>>>    /* Returns true if the process record target is open.  */
> >>>>    extern int record_full_is_used (void);
> >>>> diff --git a/gdb/riscv-tdep.c b/gdb/riscv-tdep.c
> >>>> index 6b5c9c02d46..f5b1f66844c 100644
> >>>> --- a/gdb/riscv-tdep.c
> >>>> +++ b/gdb/riscv-tdep.c
> >>>> @@ -5466,8 +5466,5 @@ riscv_process_record (struct gdbarch
> *gdbarch,
> >>>> struct regcache *regcache,
> >>>>      if (res != RECORD_SUCCESS)
> >>>>        return res;
> >>>>
> >>>> -  if (record_full_arch_list_add_end ())
> >>>> -    return -1;
> >>>> -
> >>>>      return 0;
> >>>>    }
> >>>> diff --git a/gdb/rs6000-tdep.c b/gdb/rs6000-tdep.c
> >>>> index e135df94a40..f964889a49f 100644
> >>>> --- a/gdb/rs6000-tdep.c
> >>>> +++ b/gdb/rs6000-tdep.c
> >>>> @@ -7138,8 +7138,6 @@ ppc_process_prefix_instruction (int
> insn_prefix,
> >> int
> >>>> insn_suffix,
> >>>>      if (record_full_arch_list_add_reg (regcache, PPC_PC_REGNUM))
> >>>>        return -1;
> >>>>
> >>>> -  if (record_full_arch_list_add_end ())
> >>>> -    return -1;
> >>>>      return 0;
> >>>>    }
> >>>>
> >>>> @@ -7447,8 +7445,6 @@ ppc_process_record (struct gdbarch
> *gdbarch,
> >>>> struct regcache *regcache,
> >>>>
> >>>>      if (record_full_arch_list_add_reg (regcache, PPC_PC_REGNUM))
> >>>>        return -1;
> >>>> -  if (record_full_arch_list_add_end ())
> >>>> -    return -1;
> >>>>      return 0;
> >>>>    }
> >>>>
> >>>> diff --git a/gdb/s390-linux-tdep.c b/gdb/s390-linux-tdep.c
> >>>> index 3cd6b359d13..6bea30f08dc 100644
> >>>> --- a/gdb/s390-linux-tdep.c
> >>>> +++ b/gdb/s390-linux-tdep.c
> >>>> @@ -910,9 +910,6 @@ s390_linux_record_signal (struct gdbarch
> >> *gdbarch,
> >>>> struct regcache *regcache,
> >>>>      if (record_full_arch_list_add_mem (sp, sizeof_rt_sigframe))
> >>>>        return -1;
> >>>>
> >>>> -  if (record_full_arch_list_add_end ())
> >>>> -    return -1;
> >>>> -
> >>>>      return 0;
> >>>>    }
> >>>>
> >>>> diff --git a/gdb/s390-tdep.c b/gdb/s390-tdep.c
> >>>> index f9d7bdd04e4..36ce659ea15 100644
> >>>> --- a/gdb/s390-tdep.c
> >>>> +++ b/gdb/s390-tdep.c
> >>>> @@ -7019,8 +7019,6 @@ s390_process_record (struct gdbarch
> *gdbarch,
> >>>> struct regcache *regcache,
> >>>>
> >>>>      if (record_full_arch_list_add_reg (regcache, S390_PSWA_REGNUM))
> >>>>        return -1;
> >>>> -  if (record_full_arch_list_add_end ())
> >>>> -    return -1;
> >>>>      return 0;
> >>>>    }
> >>>>
> >>>> --
> >>>> 2.53.0
> >>>>
> >>> Kind Regards,
> >>> Christina
> >>>
> >>> Intel Deutschland GmbH
> >>> Registered Address: Dornacher Strasse 1, 85622 Feldkirchen, Germany
> >>> Tel: +49 89 991 430, www.intel.de
> >>> Managing Directors: Harry Demas, Jeffrey Schneiderman, Yin Chong
> Sorrell
> >>> Chairperson of the Supervisory Board: Nicole Lau
> >>> Registered Seat: Munich
> >>> Commercial Register: Amtsgericht Muenchen HRB 186928
> >>>
> > Christina
> > Intel Deutschland GmbH
> > Registered Address: Dornacher Strasse 1, 85622 Feldkirchen, Germany
> > Tel: +49 89 991 430, www.intel.de
> > Managing Directors: Harry Demas, Jeffrey Schneiderman, Yin Chong Sorrell
> > Chairperson of the Supervisory Board: Nicole Lau
> > Registered Seat: Munich
> > Commercial Register: Amtsgericht Muenchen HRB 186928
> >
> 
> --
> Cheers,
> Guinevere Larsen
> It/she

Christina

Intel Deutschland GmbH
Registered Address: Dornacher Strasse 1, 85622 Feldkirchen, Germany
Tel: +49 89 991 430, www.intel.de
Managing Directors: Harry Demas, Jeffrey Schneiderman, Yin Chong Sorrell
Chairperson of the Supervisory Board: Nicole Lau
Registered Seat: Munich
Commercial Register: Amtsgericht Muenchen HRB 186928

  reply	other threads:[~2026-05-13  7:55 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-04-23 15:25 [PATCH v2 0/6] refactor the internals of record-full Guinevere Larsen
2026-04-23 15:25 ` [PATCH v2 1/6] gdb/record: Refactor record history Guinevere Larsen
2026-04-28  3:28   ` Thiago Jung Bauermann
2026-04-28 19:54     ` Guinevere Larsen
2026-05-06 21:16   ` Schimpe, Christina
2026-05-07 17:38     ` Guinevere Larsen
2026-05-11 15:23       ` Schimpe, Christina
2026-05-12 18:50         ` Guinevere Larsen
2026-05-13  7:54           ` Schimpe, Christina [this message]
2026-05-14 15:20             ` Guinevere Larsen
2026-04-23 15:26 ` [PATCH v2 2/6] gdb/record: remove record_full_insn_num Guinevere Larsen
2026-04-23 15:26 ` [PATCH v2 3/6] gdb/record: c++ify internal structures of record-full.c Guinevere Larsen
2026-04-28  3:29   ` Thiago Jung Bauermann
2026-04-23 15:26 ` [PATCH v2 4/6] gdb/record: make record_full_history more c++-like Guinevere Larsen
2026-04-28  3:29   ` Thiago Jung Bauermann
2026-04-23 15:26 ` [PATCH v2 5/6] gdb/record: extract the PC to record_full_instruction Guinevere Larsen
2026-04-28  3:30   ` Thiago Jung Bauermann
2026-04-23 15:26 ` [PATCH v2 6/6] gdb/record: Define new version of the record-save section Guinevere Larsen
2026-04-23 15:45   ` Eli Zaretskii

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