/* Trace file TFILE format support in GDB.
- Copyright (C) 1997-2014 Free Software Foundation, Inc.
+ Copyright (C) 1997-2019 Free Software Foundation, Inc.
This file is part of GDB.
#include "defs.h"
#include "tracefile.h"
#include "readline/tilde.h"
-#include "filestuff.h"
-#include "rsp-low.h" /* bin2hex */
+#include "gdbsupport/filestuff.h"
+#include "gdbsupport/rsp-low.h" /* bin2hex */
+#include "regcache.h"
+#include "inferior.h"
+#include "gdbthread.h"
+#include "exec.h" /* exec_bfd */
+#include "completer.h"
+#include "filenames.h"
+#include "remote.h"
+#include "xml-tdesc.h"
+#include "target-descriptions.h"
+#include "gdbsupport/buffer.h"
+#include <algorithm>
+
+#ifndef O_LARGEFILE
+#define O_LARGEFILE 0
+#endif
+
+/* The tfile target. */
+
+static const target_info tfile_target_info = {
+ "tfile",
+ N_("Local trace dump file"),
+ N_("Use a trace file as a target.\n\
+Specify the filename of the trace file.")
+};
+
+class tfile_target final : public tracefile_target
+{
+ public:
+ const target_info &info () const override
+ { return tfile_target_info; }
+
+ void close () override;
+ void fetch_registers (struct regcache *, int) override;
+ enum target_xfer_status xfer_partial (enum target_object object,
+ const char *annex,
+ gdb_byte *readbuf,
+ const gdb_byte *writebuf,
+ ULONGEST offset, ULONGEST len,
+ ULONGEST *xfered_len) override;
+ void files_info () override;
+ int trace_find (enum trace_find_type type, int num,
+ CORE_ADDR addr1, CORE_ADDR addr2, int *tpp) override;
+ bool get_trace_state_variable_value (int tsv, LONGEST *val) override;
+ traceframe_info_up traceframe_info () override;
+
+ void get_tracepoint_status (struct breakpoint *tp,
+ struct uploaded_tp *utp) override;
+};
/* TFILE trace writer. */
= (struct tfile_trace_file_writer *) self;
writer->pathname = tilde_expand (filename);
- writer->fp = gdb_fopen_cloexec (writer->pathname, "wb");
+ writer->fp = gdb_fopen_cloexec (writer->pathname, "wb").release ();
if (writer->fp == NULL)
error (_("Unable to open file '%s' for saving trace data (%s)"),
writer->pathname, safe_strerror (errno));
fprintf (writer->fp, "status %c;%s",
(ts->running ? '1' : '0'), stop_reason_names[ts->stop_reason]);
if (ts->stop_reason == tracepoint_error
- || ts->stop_reason == tstop_command)
+ || ts->stop_reason == trace_stop_command)
{
char *buf = (char *) alloca (strlen (ts->stop_desc) * 2 + 1);
tfile_write_uploaded_tsv (struct trace_file_writer *self,
struct uploaded_tsv *utsv)
{
- char *buf = "";
+ char *buf = NULL;
struct tfile_trace_file_writer *writer
= (struct tfile_trace_file_writer *) self;
fprintf (writer->fp, "tsv %x:%s:%x:%s\n",
utsv->number, phex_nz (utsv->initial_value, 8),
- utsv->builtin, buf);
+ utsv->builtin, buf != NULL ? buf : "");
if (utsv->name)
xfree (buf);
{
struct tfile_trace_file_writer *writer
= (struct tfile_trace_file_writer *) self;
- int a;
- char *act;
char buf[MAX_TRACE_UPLOAD];
fprintf (writer->fp, "tp T%x:%s:%c:%x:%x",
fprintf (writer->fp, ":F%x", utp->orig_size);
if (utp->cond)
fprintf (writer->fp,
- ":X%x,%s", (unsigned int) strlen (utp->cond) / 2,
- utp->cond);
+ ":X%x,%s", (unsigned int) strlen (utp->cond.get ()) / 2,
+ utp->cond.get ());
fprintf (writer->fp, "\n");
- for (a = 0; VEC_iterate (char_ptr, utp->actions, a, act); ++a)
+ for (const auto &act : utp->actions)
fprintf (writer->fp, "tp A%x:%s:%s\n",
- utp->number, phex_nz (utp->addr, sizeof (utp->addr)), act);
- for (a = 0; VEC_iterate (char_ptr, utp->step_actions, a, act); ++a)
+ utp->number, phex_nz (utp->addr, sizeof (utp->addr)), act.get ());
+ for (const auto &act : utp->step_actions)
fprintf (writer->fp, "tp S%x:%s:%s\n",
- utp->number, phex_nz (utp->addr, sizeof (utp->addr)), act);
+ utp->number, phex_nz (utp->addr, sizeof (utp->addr)), act.get ());
if (utp->at_string)
{
encode_source_string (utp->number, utp->addr,
- "at", utp->at_string, buf, MAX_TRACE_UPLOAD);
+ "at", utp->at_string.get (),
+ buf, MAX_TRACE_UPLOAD);
fprintf (writer->fp, "tp Z%s\n", buf);
}
if (utp->cond_string)
{
encode_source_string (utp->number, utp->addr,
- "cond", utp->cond_string,
+ "cond", utp->cond_string.get (),
buf, MAX_TRACE_UPLOAD);
fprintf (writer->fp, "tp Z%s\n", buf);
}
- for (a = 0; VEC_iterate (char_ptr, utp->cmd_strings, a, act); ++a)
+ for (const auto &act : utp->cmd_strings)
{
- encode_source_string (utp->number, utp->addr, "cmd", act,
+ encode_source_string (utp->number, utp->addr, "cmd", act.get (),
buf, MAX_TRACE_UPLOAD);
fprintf (writer->fp, "tp Z%s\n", buf);
}
sizeof (utp->traceframe_usage)));
}
+/* This is the implementation of trace_file_write_ops method
+ write_tdesc. */
+
+static void
+tfile_write_tdesc (struct trace_file_writer *self)
+{
+ struct tfile_trace_file_writer *writer
+ = (struct tfile_trace_file_writer *) self;
+
+ gdb::optional<std::string> tdesc
+ = target_fetch_description_xml (current_top_target ());
+
+ if (!tdesc)
+ return;
+
+ const char *ptr = tdesc->c_str ();
+
+ /* Write tdesc line by line, prefixing each line with "tdesc ". */
+ while (ptr != NULL)
+ {
+ const char *next = strchr (ptr, '\n');
+ if (next != NULL)
+ {
+ fprintf (writer->fp, "tdesc %.*s\n", (int) (next - ptr), ptr);
+ /* Skip the \n. */
+ next++;
+ }
+ else if (*ptr != '\0')
+ {
+ /* Last line, doesn't have a newline. */
+ fprintf (writer->fp, "tdesc %s\n", ptr);
+ }
+ ptr = next;
+ }
+}
+
/* This is the implementation of trace_file_write_ops method
write_definition_end. */
tfile_write_status,
tfile_write_uploaded_tsv,
tfile_write_uploaded_tp,
+ tfile_write_tdesc,
tfile_write_definition_end,
tfile_write_raw_data,
NULL,
tfile_trace_file_writer_new (void)
{
struct tfile_trace_file_writer *writer
- = xmalloc (sizeof (struct tfile_trace_file_writer));
+ = XNEW (struct tfile_trace_file_writer);
writer->base.ops = &tfile_write_ops;
writer->fp = NULL;
return (struct trace_file_writer *) writer;
}
+
+/* target tfile command */
+
+static tfile_target tfile_ops;
+
+#define TRACE_HEADER_SIZE 8
+
+#define TFILE_PID (1)
+
+static char *trace_filename;
+static int trace_fd = -1;
+static off_t trace_frames_offset;
+static off_t cur_offset;
+static int cur_data_size;
+int trace_regblock_size;
+static struct buffer trace_tdesc;
+
+static void tfile_append_tdesc_line (const char *line);
+static void tfile_interp_line (char *line,
+ struct uploaded_tp **utpp,
+ struct uploaded_tsv **utsvp);
+
+/* Read SIZE bytes into READBUF from the trace frame, starting at
+ TRACE_FD's current position. Note that this call `read'
+ underneath, hence it advances the file's seek position. Throws an
+ error if the `read' syscall fails, or less than SIZE bytes are
+ read. */
+
+static void
+tfile_read (gdb_byte *readbuf, int size)
+{
+ int gotten;
+
+ gotten = read (trace_fd, readbuf, size);
+ if (gotten < 0)
+ perror_with_name (trace_filename);
+ else if (gotten < size)
+ error (_("Premature end of file while reading trace file"));
+}
+
+/* Open the tfile target. */
+
+static void
+tfile_target_open (const char *arg, int from_tty)
+{
+ int flags;
+ int scratch_chan;
+ char header[TRACE_HEADER_SIZE];
+ char linebuf[1000]; /* Should be max remote packet size or so. */
+ gdb_byte byte;
+ int bytes, i;
+ struct trace_status *ts;
+ struct uploaded_tp *uploaded_tps = NULL;
+ struct uploaded_tsv *uploaded_tsvs = NULL;
+
+ target_preopen (from_tty);
+ if (!arg)
+ error (_("No trace file specified."));
+
+ gdb::unique_xmalloc_ptr<char> filename (tilde_expand (arg));
+ if (!IS_ABSOLUTE_PATH (filename.get ()))
+ filename.reset (concat (current_directory, "/", filename.get (),
+ (char *) NULL));
+
+ flags = O_BINARY | O_LARGEFILE;
+ flags |= O_RDONLY;
+ scratch_chan = gdb_open_cloexec (filename.get (), flags, 0);
+ if (scratch_chan < 0)
+ perror_with_name (filename.get ());
+
+ /* Looks semi-reasonable. Toss the old trace file and work on the new. */
+
+ unpush_target (&tfile_ops);
+
+ trace_filename = filename.release ();
+ trace_fd = scratch_chan;
+
+ /* Make sure this is clear. */
+ buffer_free (&trace_tdesc);
+
+ bytes = 0;
+ /* Read the file header and test for validity. */
+ tfile_read ((gdb_byte *) &header, TRACE_HEADER_SIZE);
+
+ bytes += TRACE_HEADER_SIZE;
+ if (!(header[0] == 0x7f
+ && (startswith (header + 1, "TRACE0\n"))))
+ error (_("File is not a valid trace file."));
+
+ push_target (&tfile_ops);
+
+ trace_regblock_size = 0;
+ ts = current_trace_status ();
+ /* We know we're working with a file. Record its name. */
+ ts->filename = trace_filename;
+ /* Set defaults in case there is no status line. */
+ ts->running_known = 0;
+ ts->stop_reason = trace_stop_reason_unknown;
+ ts->traceframe_count = -1;
+ ts->buffer_free = 0;
+ ts->disconnected_tracing = 0;
+ ts->circular_buffer = 0;
+
+ try
+ {
+ /* Read through a section of newline-terminated lines that
+ define things like tracepoints. */
+ i = 0;
+ while (1)
+ {
+ tfile_read (&byte, 1);
+
+ ++bytes;
+ if (byte == '\n')
+ {
+ /* Empty line marks end of the definition section. */
+ if (i == 0)
+ break;
+ linebuf[i] = '\0';
+ i = 0;
+ tfile_interp_line (linebuf, &uploaded_tps, &uploaded_tsvs);
+ }
+ else
+ linebuf[i++] = byte;
+ if (i >= 1000)
+ error (_("Excessively long lines in trace file"));
+ }
+
+ /* By now, tdesc lines have been read from tfile - let's parse them. */
+ target_find_description ();
+
+ /* Record the starting offset of the binary trace data. */
+ trace_frames_offset = bytes;
+
+ /* If we don't have a blocksize, we can't interpret the
+ traceframes. */
+ if (trace_regblock_size == 0)
+ error (_("No register block size recorded in trace file"));
+ }
+ catch (const gdb_exception &ex)
+ {
+ /* Remove the partially set up target. */
+ unpush_target (&tfile_ops);
+ throw;
+ }
+
+ inferior_appeared (current_inferior (), TFILE_PID);
+ inferior_ptid = ptid_t (TFILE_PID);
+ add_thread_silent (inferior_ptid);
+
+ if (ts->traceframe_count <= 0)
+ warning (_("No traceframes present in this file."));
+
+ /* Add the file's tracepoints and variables into the current mix. */
+
+ /* Get trace state variables first, they may be checked when parsing
+ uploaded commands. */
+ merge_uploaded_trace_state_variables (&uploaded_tsvs);
+
+ merge_uploaded_tracepoints (&uploaded_tps);
+
+ post_create_inferior (&tfile_ops, from_tty);
+}
+
+/* Interpret the given line from the definitions part of the trace
+ file. */
+
+static void
+tfile_interp_line (char *line, struct uploaded_tp **utpp,
+ struct uploaded_tsv **utsvp)
+{
+ char *p = line;
+
+ if (startswith (p, "R "))
+ {
+ p += strlen ("R ");
+ trace_regblock_size = strtol (p, &p, 16);
+ }
+ else if (startswith (p, "status "))
+ {
+ p += strlen ("status ");
+ parse_trace_status (p, current_trace_status ());
+ }
+ else if (startswith (p, "tp "))
+ {
+ p += strlen ("tp ");
+ parse_tracepoint_definition (p, utpp);
+ }
+ else if (startswith (p, "tsv "))
+ {
+ p += strlen ("tsv ");
+ parse_tsv_definition (p, utsvp);
+ }
+ else if (startswith (p, "tdesc "))
+ {
+ p += strlen ("tdesc ");
+ tfile_append_tdesc_line (p);
+ }
+ else
+ warning (_("Ignoring trace file definition \"%s\""), line);
+}
+
+/* Close the trace file and generally clean up. */
+
+void
+tfile_target::close ()
+{
+ if (trace_fd < 0)
+ return;
+
+ inferior_ptid = null_ptid; /* Avoid confusion from thread stuff. */
+ exit_inferior_silent (current_inferior ());
+
+ ::close (trace_fd);
+ trace_fd = -1;
+ xfree (trace_filename);
+ trace_filename = NULL;
+ buffer_free (&trace_tdesc);
+
+ trace_reset_local_state ();
+}
+
+void
+tfile_target::files_info ()
+{
+ printf_filtered ("\t`%s'\n", trace_filename);
+}
+
+void
+tfile_target::get_tracepoint_status (struct breakpoint *tp, struct uploaded_tp *utp)
+{
+ /* Other bits of trace status were collected as part of opening the
+ trace files, so nothing to do here. */
+}
+
+/* Given the position of a traceframe in the file, figure out what
+ address the frame was collected at. This would normally be the
+ value of a collected PC register, but if not available, we
+ improvise. */
+
+static CORE_ADDR
+tfile_get_traceframe_address (off_t tframe_offset)
+{
+ CORE_ADDR addr = 0;
+ short tpnum;
+ struct tracepoint *tp;
+ off_t saved_offset = cur_offset;
+
+ /* FIXME dig pc out of collected registers. */
+
+ /* Fall back to using tracepoint address. */
+ lseek (trace_fd, tframe_offset, SEEK_SET);
+ tfile_read ((gdb_byte *) &tpnum, 2);
+ tpnum = (short) extract_signed_integer ((gdb_byte *) &tpnum, 2,
+ gdbarch_byte_order
+ (target_gdbarch ()));
+
+ tp = get_tracepoint_by_number_on_target (tpnum);
+ /* FIXME this is a poor heuristic if multiple locations. */
+ if (tp && tp->loc)
+ addr = tp->loc->address;
+
+ /* Restore our seek position. */
+ cur_offset = saved_offset;
+ lseek (trace_fd, cur_offset, SEEK_SET);
+ return addr;
+}
+
+/* Given a type of search and some parameters, scan the collection of
+ traceframes in the file looking for a match. When found, return
+ both the traceframe and tracepoint number, otherwise -1 for
+ each. */
+
+int
+tfile_target::trace_find (enum trace_find_type type, int num,
+ CORE_ADDR addr1, CORE_ADDR addr2, int *tpp)
+{
+ short tpnum;
+ int tfnum = 0, found = 0;
+ unsigned int data_size;
+ struct tracepoint *tp;
+ off_t offset, tframe_offset;
+ CORE_ADDR tfaddr;
+
+ if (num == -1)
+ {
+ if (tpp)
+ *tpp = -1;
+ return -1;
+ }
+
+ lseek (trace_fd, trace_frames_offset, SEEK_SET);
+ offset = trace_frames_offset;
+ while (1)
+ {
+ tframe_offset = offset;
+ tfile_read ((gdb_byte *) &tpnum, 2);
+ tpnum = (short) extract_signed_integer ((gdb_byte *) &tpnum, 2,
+ gdbarch_byte_order
+ (target_gdbarch ()));
+ offset += 2;
+ if (tpnum == 0)
+ break;
+ tfile_read ((gdb_byte *) &data_size, 4);
+ data_size = (unsigned int) extract_unsigned_integer
+ ((gdb_byte *) &data_size, 4,
+ gdbarch_byte_order (target_gdbarch ()));
+ offset += 4;
+
+ if (type == tfind_number)
+ {
+ /* Looking for a specific trace frame. */
+ if (tfnum == num)
+ found = 1;
+ }
+ else
+ {
+ /* Start from the _next_ trace frame. */
+ if (tfnum > get_traceframe_number ())
+ {
+ switch (type)
+ {
+ case tfind_pc:
+ tfaddr = tfile_get_traceframe_address (tframe_offset);
+ if (tfaddr == addr1)
+ found = 1;
+ break;
+ case tfind_tp:
+ tp = get_tracepoint (num);
+ if (tp && tpnum == tp->number_on_target)
+ found = 1;
+ break;
+ case tfind_range:
+ tfaddr = tfile_get_traceframe_address (tframe_offset);
+ if (addr1 <= tfaddr && tfaddr <= addr2)
+ found = 1;
+ break;
+ case tfind_outside:
+ tfaddr = tfile_get_traceframe_address (tframe_offset);
+ if (!(addr1 <= tfaddr && tfaddr <= addr2))
+ found = 1;
+ break;
+ default:
+ internal_error (__FILE__, __LINE__, _("unknown tfind type"));
+ }
+ }
+ }
+
+ if (found)
+ {
+ if (tpp)
+ *tpp = tpnum;
+ cur_offset = offset;
+ cur_data_size = data_size;
+
+ return tfnum;
+ }
+ /* Skip past the traceframe's data. */
+ lseek (trace_fd, data_size, SEEK_CUR);
+ offset += data_size;
+ /* Update our own count of traceframes. */
+ ++tfnum;
+ }
+ /* Did not find what we were looking for. */
+ if (tpp)
+ *tpp = -1;
+ return -1;
+}
+
+/* Prototype of the callback passed to tframe_walk_blocks. */
+typedef int (*walk_blocks_callback_func) (char blocktype, void *data);
+
+/* Callback for traceframe_walk_blocks, used to find a given block
+ type in a traceframe. */
+
+static int
+match_blocktype (char blocktype, void *data)
+{
+ char *wantedp = (char *) data;
+
+ if (*wantedp == blocktype)
+ return 1;
+
+ return 0;
+}
+
+/* Walk over all traceframe block starting at POS offset from
+ CUR_OFFSET, and call CALLBACK for each block found, passing in DATA
+ unmodified. If CALLBACK returns true, this returns the position in
+ the traceframe where the block is found, relative to the start of
+ the traceframe (cur_offset). Returns -1 if no callback call
+ returned true, indicating that all blocks have been walked. */
+
+static int
+traceframe_walk_blocks (walk_blocks_callback_func callback,
+ int pos, void *data)
+{
+ /* Iterate through a traceframe's blocks, looking for a block of the
+ requested type. */
+
+ lseek (trace_fd, cur_offset + pos, SEEK_SET);
+ while (pos < cur_data_size)
+ {
+ unsigned short mlen;
+ char block_type;
+
+ tfile_read ((gdb_byte *) &block_type, 1);
+
+ ++pos;
+
+ if ((*callback) (block_type, data))
+ return pos;
+
+ switch (block_type)
+ {
+ case 'R':
+ lseek (trace_fd, cur_offset + pos + trace_regblock_size, SEEK_SET);
+ pos += trace_regblock_size;
+ break;
+ case 'M':
+ lseek (trace_fd, cur_offset + pos + 8, SEEK_SET);
+ tfile_read ((gdb_byte *) &mlen, 2);
+ mlen = (unsigned short)
+ extract_unsigned_integer ((gdb_byte *) &mlen, 2,
+ gdbarch_byte_order
+ (target_gdbarch ()));
+ lseek (trace_fd, mlen, SEEK_CUR);
+ pos += (8 + 2 + mlen);
+ break;
+ case 'V':
+ lseek (trace_fd, cur_offset + pos + 4 + 8, SEEK_SET);
+ pos += (4 + 8);
+ break;
+ default:
+ error (_("Unknown block type '%c' (0x%x) in trace frame"),
+ block_type, block_type);
+ break;
+ }
+ }
+
+ return -1;
+}
+
+/* Convenience wrapper around traceframe_walk_blocks. Looks for the
+ position offset of a block of type TYPE_WANTED in the current trace
+ frame, starting at POS. Returns -1 if no such block was found. */
+
+static int
+traceframe_find_block_type (char type_wanted, int pos)
+{
+ return traceframe_walk_blocks (match_blocktype, pos, &type_wanted);
+}
+
+/* Look for a block of saved registers in the traceframe, and get the
+ requested register from it. */
+
+void
+tfile_target::fetch_registers (struct regcache *regcache, int regno)
+{
+ struct gdbarch *gdbarch = regcache->arch ();
+ int offset, regn, regsize, dummy;
+
+ /* An uninitialized reg size says we're not going to be
+ successful at getting register blocks. */
+ if (!trace_regblock_size)
+ return;
+
+ if (traceframe_find_block_type ('R', 0) >= 0)
+ {
+ gdb_byte *regs = (gdb_byte *) alloca (trace_regblock_size);
+
+ tfile_read (regs, trace_regblock_size);
+
+ for (regn = 0; regn < gdbarch_num_regs (gdbarch); regn++)
+ {
+ if (!remote_register_number_and_offset (regcache->arch (),
+ regn, &dummy, &offset))
+ continue;
+
+ regsize = register_size (gdbarch, regn);
+ /* Make sure we stay within block bounds. */
+ if (offset + regsize > trace_regblock_size)
+ break;
+ if (regcache->get_register_status (regn) == REG_UNKNOWN)
+ {
+ if (regno == regn)
+ {
+ regcache->raw_supply (regno, regs + offset);
+ break;
+ }
+ else if (regno == -1)
+ {
+ regcache->raw_supply (regn, regs + offset);
+ }
+ }
+ }
+ }
+ else
+ tracefile_fetch_registers (regcache, regno);
+}
+
+static enum target_xfer_status
+tfile_xfer_partial_features (const char *annex,
+ gdb_byte *readbuf, const gdb_byte *writebuf,
+ ULONGEST offset, ULONGEST len,
+ ULONGEST *xfered_len)
+{
+ if (strcmp (annex, "target.xml"))
+ return TARGET_XFER_E_IO;
+
+ if (readbuf == NULL)
+ error (_("tfile_xfer_partial: tdesc is read-only"));
+
+ if (trace_tdesc.used_size == 0)
+ return TARGET_XFER_E_IO;
+
+ if (offset >= trace_tdesc.used_size)
+ return TARGET_XFER_EOF;
+
+ if (len > trace_tdesc.used_size - offset)
+ len = trace_tdesc.used_size - offset;
+
+ memcpy (readbuf, trace_tdesc.buffer + offset, len);
+ *xfered_len = len;
+
+ return TARGET_XFER_OK;
+}
+
+enum target_xfer_status
+tfile_target::xfer_partial (enum target_object object,
+ const char *annex, gdb_byte *readbuf,
+ const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
+ ULONGEST *xfered_len)
+{
+ /* We're only doing regular memory and tdesc for now. */
+ if (object == TARGET_OBJECT_AVAILABLE_FEATURES)
+ return tfile_xfer_partial_features (annex, readbuf, writebuf,
+ offset, len, xfered_len);
+ if (object != TARGET_OBJECT_MEMORY)
+ return TARGET_XFER_E_IO;
+
+ if (readbuf == NULL)
+ error (_("tfile_xfer_partial: trace file is read-only"));
+
+ if (get_traceframe_number () != -1)
+ {
+ int pos = 0;
+ enum target_xfer_status res;
+ /* Records the lowest available address of all blocks that
+ intersects the requested range. */
+ ULONGEST low_addr_available = 0;
+
+ /* Iterate through the traceframe's blocks, looking for
+ memory. */
+ while ((pos = traceframe_find_block_type ('M', pos)) >= 0)
+ {
+ ULONGEST maddr, amt;
+ unsigned short mlen;
+ enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
+
+ tfile_read ((gdb_byte *) &maddr, 8);
+ maddr = extract_unsigned_integer ((gdb_byte *) &maddr, 8,
+ byte_order);
+ tfile_read ((gdb_byte *) &mlen, 2);
+ mlen = (unsigned short)
+ extract_unsigned_integer ((gdb_byte *) &mlen, 2, byte_order);
+
+ /* If the block includes the first part of the desired
+ range, return as much it has; GDB will re-request the
+ remainder, which might be in a different block of this
+ trace frame. */
+ if (maddr <= offset && offset < (maddr + mlen))
+ {
+ amt = (maddr + mlen) - offset;
+ if (amt > len)
+ amt = len;
+
+ if (maddr != offset)
+ lseek (trace_fd, offset - maddr, SEEK_CUR);
+ tfile_read (readbuf, amt);
+ *xfered_len = amt;
+ return TARGET_XFER_OK;
+ }
+
+ if (offset < maddr && maddr < (offset + len))
+ if (low_addr_available == 0 || low_addr_available > maddr)
+ low_addr_available = maddr;
+
+ /* Skip over this block. */
+ pos += (8 + 2 + mlen);
+ }
+
+ /* Requested memory is unavailable in the context of traceframes,
+ and this address falls within a read-only section, fallback
+ to reading from executable, up to LOW_ADDR_AVAILABLE. */
+ if (offset < low_addr_available)
+ len = std::min (len, low_addr_available - offset);
+ res = exec_read_partial_read_only (readbuf, offset, len, xfered_len);
+
+ if (res == TARGET_XFER_OK)
+ return TARGET_XFER_OK;
+ else
+ {
+ /* No use trying further, we know some memory starting
+ at MEMADDR isn't available. */
+ *xfered_len = len;
+ return TARGET_XFER_UNAVAILABLE;
+ }
+ }
+ else
+ {
+ /* Fallback to reading from read-only sections. */
+ return section_table_read_available_memory (readbuf, offset, len,
+ xfered_len);
+ }
+}
+
+/* Iterate through the blocks of a trace frame, looking for a 'V'
+ block with a matching tsv number. */
+
+bool
+tfile_target::get_trace_state_variable_value (int tsvnum, LONGEST *val)
+{
+ int pos;
+ bool found = false;
+
+ /* Iterate over blocks in current frame and find the last 'V'
+ block in which tsv number is TSVNUM. In one trace frame, there
+ may be multiple 'V' blocks created for a given trace variable,
+ and the last matched 'V' block contains the updated value. */
+ pos = 0;
+ while ((pos = traceframe_find_block_type ('V', pos)) >= 0)
+ {
+ int vnum;
+
+ tfile_read ((gdb_byte *) &vnum, 4);
+ vnum = (int) extract_signed_integer ((gdb_byte *) &vnum, 4,
+ gdbarch_byte_order
+ (target_gdbarch ()));
+ if (tsvnum == vnum)
+ {
+ tfile_read ((gdb_byte *) val, 8);
+ *val = extract_signed_integer ((gdb_byte *) val, 8,
+ gdbarch_byte_order
+ (target_gdbarch ()));
+ found = true;
+ }
+ pos += (4 + 8);
+ }
+
+ return found;
+}
+
+/* Callback for traceframe_walk_blocks. Builds a traceframe_info
+ object for the tfile target's current traceframe. */
+
+static int
+build_traceframe_info (char blocktype, void *data)
+{
+ struct traceframe_info *info = (struct traceframe_info *) data;
+
+ switch (blocktype)
+ {
+ case 'M':
+ {
+ ULONGEST maddr;
+ unsigned short mlen;
+
+ tfile_read ((gdb_byte *) &maddr, 8);
+ maddr = extract_unsigned_integer ((gdb_byte *) &maddr, 8,
+ gdbarch_byte_order
+ (target_gdbarch ()));
+ tfile_read ((gdb_byte *) &mlen, 2);
+ mlen = (unsigned short)
+ extract_unsigned_integer ((gdb_byte *) &mlen,
+ 2, gdbarch_byte_order
+ (target_gdbarch ()));
+
+ info->memory.emplace_back (maddr, mlen);
+ break;
+ }
+ case 'V':
+ {
+ int vnum;
+
+ tfile_read ((gdb_byte *) &vnum, 4);
+ info->tvars.push_back (vnum);
+ }
+ case 'R':
+ case 'S':
+ {
+ break;
+ }
+ default:
+ warning (_("Unhandled trace block type (%d) '%c ' "
+ "while building trace frame info."),
+ blocktype, blocktype);
+ break;
+ }
+
+ return 0;
+}
+
+traceframe_info_up
+tfile_target::traceframe_info ()
+{
+ traceframe_info_up info (new struct traceframe_info);
+
+ traceframe_walk_blocks (build_traceframe_info, 0, info.get ());
+
+ return info;
+}
+
+/* Handles tdesc lines from tfile by appending the payload to
+ a global trace_tdesc variable. */
+
+static void
+tfile_append_tdesc_line (const char *line)
+{
+ buffer_grow_str (&trace_tdesc, line);
+ buffer_grow_str (&trace_tdesc, "\n");
+}
+
+void
+_initialize_tracefile_tfile (void)
+{
+ add_target (tfile_target_info, tfile_target_open, filename_completer);
+}