9b409511d0
This patch does the conversion of to_xfer_partial from LONGEST (*to_xfer_partial) (struct target_ops *ops, enum target_object object, const char *annex, gdb_byte *readbuf, const gdb_byte *writebuf, ULONGEST offset, ULONGEST len); to enum target_xfer_status (*to_xfer_partial) (struct target_ops *ops, enum target_object object, const char *annex, gdb_byte *readbuf, const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, ULONGEST *xfered_len); It changes to_xfer_partial return the transfer status and the transfered length by *XFERED_LEN. Generally, the return status has three stats, - TARGET_XFER_OK, - TARGET_XFER_EOF, - TARGET_XFER_E_XXXX, See the comments to them in 'enum target_xfer_status'. Note that Pedro suggested not name TARGET_XFER_DONE, as it is confusing, compared with "TARGET_XFER_OK". We finally name it TARGET_XFER_EOF. With this change, GDB core can handle unavailable data in a convenient way. The rationale behind this change was mentioned here https://sourceware.org/ml/gdb-patches/2013-10/msg00761.html Consider an object/value like this: 0 100 150 200 512 DDDDDDDDDDDxxxxxxxxxDDDDDD...DDIIIIIIIIIIII..III where D is valid data, and xxx is unavailable data, and I is beyond the end of the object (Invalid). Currently, if we start the xfer at 0, requesting, say 512 bytes, we'll first get back 100 bytes. The xfer machinery then retries fetching [100,512), and gets back TARGET_XFER_E_UNAVAILABLE. That's sufficient when you're either interested in either having the whole of the 512 bytes available, or erroring out. But, in this scenario, we're interested in the data at [150,512). The problem is that the last TARGET_XFER_E_UNAVAILABLE gives us no indication where to start the read next. We'd need something like: get me [0,512) >>> <<< here's [0,100), *xfered_len is 100, returns TARGET_XFER_OK get me [100,512) >>> (**1) <<< [100,150) is unavailable, *xfered_len is 50, return TARGET_XFER_E_UNAVAILABLE. get me [150,512) >>> <<< here's [150,200), *xfered_len is 50, return TARGET_XFER_OK. get me [200,512) >>> <<< no more data, return TARGET_XFER_EOF. This naturally implies pushing down the decision of whether to return TARGET_XFER_E_UNAVAILABLE or something else down to the target. (Which kinds of leads back to tfile itself reading from RO memory from file (though we could export a function in exec.c for that that tfile delegates to, instead of re-adding the old code). Beside this change, we also add a macro TARGET_XFER_STATUS_ERROR_P to check whether a status is an error or not, to stop using "status < 0". This patch also eliminates the comparison between status and 0. No target implementations to to_xfer_partial adapts this new interface. The interface still behaves as before. gdb: 2014-02-11 Yao Qi <yao@codesourcery.com> * target.h (enum target_xfer_error): Rename to ... (enum target_xfer_status): ... it. New. All users updated. (enum target_xfer_status) <TARGET_XFER_OK>, <TARGET_XFER_EOF>: New. (TARGET_XFER_STATUS_ERROR_P): New macro. (target_xfer_error_to_string): Remove declaration. (target_xfer_status_to_string): Declare. (target_xfer_partial_ftype): Adjust it. (struct target_ops) <to_xfer_partial>: Return target_xfer_status. Add argument xfered_len. Update comments. * target.c (target_xfer_error_to_string): Rename to ... (target_xfer_status_to_string): ... it. New. All callers updated. (target_read_live_memory): Likewise. Call target_xfer_partial instead of target_read. (memory_xfer_live_readonly_partial): Return target_xfer_status. Add argument xfered_len. (raw_memory_xfer_partial): Likewise. (memory_xfer_partial_1): Likewise. (memory_xfer_partial): Likewise. (target_xfer_partial): Likewise. Check *XFERED_LEN is set properly. Update debug message. (default_xfer_partial, current_xfer_partial): Likewise. (target_write_partial): Likewise. (target_read_partial): Likewise. All callers updated. (read_whatever_is_readable): Likewise. (target_write_with_progress): Likewise. (target_read_alloc_1): Likewise. * aix-thread.c (aix_thread_xfer_partial): Likewise. * auxv.c (procfs_xfer_auxv): Likewise. (ld_so_xfer_auxv, memory_xfer_auxv): Likewise. * bfd-target.c (target_bfd_xfer_partial): Likewise. * bsd-kvm.c (bsd_kvm_xfer_partial): Likewise. * bsd-uthread.c (bsd_uthread_xfer_partia): Likewise. * corefile.c (read_memory): Adjust. * corelow.c (core_xfer_partial): Likewise. * ctf.c (ctf_xfer_partial): Likewise. * darwin-nat.c (darwin_read_dyld_info): Likewise. All callers updated. (darwin_xfer_partial): Likewise. * exec.c (section_table_xfer_memory_partial): Likewise. All callers updated. (exec_xfer_partial): Likewise. * exec.h (section_table_xfer_memory_partial): Update declaration. * gnu-nat.c (gnu_xfer_memory): Likewise. Assert 'res' is not negative. (gnu_xfer_partial): Likewise. * ia64-hpux-nat.c (ia64_hpux_xfer_memory_no_bs): Likewise. (ia64_hpux_xfer_memory, ia64_hpux_xfer_uregs): Likewise. (ia64_hpux_xfer_solib_got): Likewise. * inf-ptrace.c (inf_ptrace_xfer_partial): Likewise. Change type of 'partial_len' to ULONGEST. * inf-ttrace.c (inf_ttrace_xfer_partial): Likewise. * linux-nat.c (linux_xfer_siginfo ): Likewise. (linux_nat_xfer_partial): Likewise. (linux_proc_xfer_partial, linux_xfer_partial): Likewise. (linux_proc_xfer_spu, linux_nat_xfer_osdata): Likewise. * monitor.c (monitor_xfer_memory): Likewise. (monitor_xfer_partial): Likewise. * procfs.c (procfs_xfer_partial): Likewise. * record-btrace.c (record_btrace_xfer_partial): Likewise. * record-full.c (record_full_xfer_partial): Likewise. (record_full_core_xfer_partial): Likewise. * remote-sim.c (gdbsim_xfer_memory): Likewise. (gdbsim_xfer_partial): Likewise. * remote.c (remote_write_bytes_aux): Likewise. All callers updated. (remote_write_bytes, remote_read_bytes): Likewise. All callers updated. (remote_flash_erase): Likewise. All callers updated. (remote_write_qxfer): Likewise. All callers updated. (remote_read_qxfer): Likewise. All callers updated. (remote_xfer_partial): Likewise. * rs6000-nat.c (rs6000_xfer_partial): Likewise. (rs6000_xfer_shared_libraries): Likewise. * sol-thread.c (sol_thread_xfer_partial): Likewise. (sol_thread_xfer_partial): Likewise. * sparc-nat.c (sparc_xfer_wcookie): Likewise. (sparc_xfer_partial): Likewise. * spu-linux-nat.c (spu_proc_xfer_spu): Likewise. All callers updated. (spu_xfer_partial): Likewise. * spu-multiarch.c (spu_xfer_partial): Likewise. * tracepoint.c (tfile_xfer_partial): Likewise. * windows-nat.c (windows_xfer_memory): Likewise. (windows_xfer_shared_libraries): Likewise. (windows_xfer_partial): Likewise. * valprint.c: Replace 'target_xfer_error' with 'target_xfer_status' in comments.
104 lines
2.8 KiB
C
104 lines
2.8 KiB
C
/* Very simple "bfd" target, for GDB, the GNU debugger.
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Copyright (C) 2003-2014 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include "defs.h"
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#include "target.h"
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#include "bfd-target.h"
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#include "exec.h"
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#include "gdb_bfd.h"
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/* The object that is stored in the target_ops->to_data field has this
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type. */
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struct target_bfd_data
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{
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/* The BFD we're wrapping. */
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struct bfd *bfd;
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/* The section table build from the ALLOC sections in BFD. Note
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that we can't rely on extracting the BFD from a random section in
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the table, since the table can be legitimately empty. */
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struct target_section_table table;
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};
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static enum target_xfer_status
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target_bfd_xfer_partial (struct target_ops *ops,
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enum target_object object,
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const char *annex, gdb_byte *readbuf,
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const gdb_byte *writebuf,
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ULONGEST offset, ULONGEST len,
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ULONGEST *xfered_len)
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{
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switch (object)
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{
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case TARGET_OBJECT_MEMORY:
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{
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struct target_bfd_data *data = ops->to_data;
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return section_table_xfer_memory_partial (readbuf, writebuf,
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offset, len, xfered_len,
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data->table.sections,
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data->table.sections_end,
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NULL);
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}
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default:
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return TARGET_XFER_E_IO;
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}
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}
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static struct target_section_table *
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target_bfd_get_section_table (struct target_ops *ops)
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{
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struct target_bfd_data *data = ops->to_data;
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return &data->table;
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}
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static void
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target_bfd_xclose (struct target_ops *t)
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{
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struct target_bfd_data *data = t->to_data;
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gdb_bfd_unref (data->bfd);
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xfree (data->table.sections);
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xfree (data);
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xfree (t);
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}
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struct target_ops *
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target_bfd_reopen (struct bfd *abfd)
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{
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struct target_ops *t;
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struct target_bfd_data *data;
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data = XCNEW (struct target_bfd_data);
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data->bfd = abfd;
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gdb_bfd_ref (abfd);
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build_section_table (abfd, &data->table.sections, &data->table.sections_end);
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t = XCNEW (struct target_ops);
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t->to_shortname = "bfd";
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t->to_longname = _("BFD backed target");
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t->to_doc = _("You should never see this");
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t->to_get_section_table = target_bfd_get_section_table;
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t->to_xfer_partial = target_bfd_xfer_partial;
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t->to_xclose = target_bfd_xclose;
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t->to_data = data;
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t->to_magic = OPS_MAGIC;
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return t;
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}
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