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2021-08-03gdb: follow-fork: push target and add thread in target_follow_forkSimon Marchi1-3/+4
In the context of ROCm-gdb [1], the ROCm target sits on top of the linux-nat target. when a process forks, it needs to carry over some data from the forking inferior to the fork child inferior. Ideally, the ROCm target would implement the follow_fork target_ops method, but there are some small problems. This patch fixes these, which helps the ROCm target, but also makes things more consistent and a bit nicer in general, I believe. The main problem is: when follow-fork-mode is "parent", target_follow_fork is called with the parent as the current inferior. When it's "child", target_follow_fork is called with the child as the current inferior. This means that target_follow_fork is sometimes called on the parent's target stack and sometimes on the child's target stack. The parent's target stack may contain targets above the process target, such as the ROCm target. So if follow-fork-child is "parent", the ROCm target would get notified of the fork and do whatever is needed. But the child's target stack, at that moment, only contains the exec and process target copied over from the parent. The child's target stack is set up by follow_fork_inferior, before calling target_follow_fork. In that case, the ROCm target wouldn't get notified of the fork. For consistency, I think it would be good to always call target_follow_fork on the parent inferior's target stack. I think it makes sense as a way to indicate "this inferior has called fork, do whatever is needed". The desired outcome of the fork (whether an inferior is created for the child, do we need to detach from the child) can be indicated by passed parameter. I therefore propose these changes: - make follow_fork_inferior always call target_follow_fork with the parent as the current inferior. That lets all targets present on the parent's target stack do some fork-related handling and push themselves on the fork child's target stack if needed. For this purpose, pass the child inferior down to target_follow_fork and follow_fork implementations. This is nullptr if no inferior is created for the child, because we want to detach from it. - as a result, in follow_fork_inferior, detach from the parent inferior (if needed) only after the target_follow_fork call. This is needed because we want to call target_follow_fork before the parent's target stack is torn down. - hand over to the targets in the parent's target stack (including the process target) the responsibility to push themselves, if needed, to the child's target stack. Also hand over the responsibility to the process target, at the same time, to create the child's initial thread (just like we do for follow_exec). - pass the child inferior to exec_on_vfork, so we don't need to swap the current inferior between parent and child. Nothing in exec_on_vfork depends on the current inferior, after this change. Although this could perhaps be replaced with just having the exec target implement follow_fork and push itself in the child's target stack, like the process target does... We would just need to make sure the process target calls beneath()->follow_fork(...). I'm not sure about this one. gdb/ChangeLog: * target.h (struct target_ops) <follow_fork>: Add inferior* parameter. (target_follow_fork): Likewise. * target.c (default_follow_fork): Likewise. (target_follow_fork): Likewise. * fbsd-nat.h (class fbsd_nat_target) <follow_fork>: Likewise. (fbsd_nat_target::follow_fork): Likewise, and call inf_ptrace_target::follow_fork. * linux-nat.h (class linux_nat_target) <follow_fork>: Likewise. * linux-nat.c (linux_nat_target::follow_fork): Likewise, and call inf_ptrace_target::follow_fork. * obsd-nat.h (obsd_nat_target) <follow_fork>: Likewise. * obsd-nat.c (obsd_nat_target::follow_fork): Likewise, and call inf_ptrace_target::follow_fork. * remote.c (class remote_target) <follow_fork>: Likewise. (remote_target::follow_fork): Likewise, and call process_stratum_target::follow_fork. * process-stratum-target.h (class process_stratum_target) <follow_fork>: New. * process-stratum-target.c (process_stratum_target::follow_fork): New. * target-delegates.c: Re-generate. [1] https://github.com/ROCm-Developer-Tools/ROCgdb Change-Id: I460bd0af850f0485e8aed4b24c6d8262a4c69929
2021-07-14gdb: pass child_ptid and fork kind to target_ops::follow_forkSimon Marchi1-7/+8
This is a small cleanup I think would be nice, that I spotted while doing the following patch. gdb/ChangeLog: * target.h (struct target_ops) <follow_fork>: Add ptid and target_waitkind parameters. (target_follow_fork): Likewise. * target.c (default_follow_fork): Likewise. (target_follow_fork): Likewise. * fbsd-nat.h (class fbsd_nat_target) <follow_fork>: Likewise. * fbsd-nat.c (fbsd_nat_target::follow_fork): Likewise. * linux-nat.h (class linux_nat_target) <follow_fork>: Likewise. * linux-nat.c (linux_nat_target::follow_fork): Likewise. * obsd-nat.h (class obsd_nat_target) <follow_fork>: Likewise. * obsd-nat.c (obsd_nat_target::follow_fork): Likewise. * remote.c (class remote_target) <follow_fork>: Likewise. * target-debug.h (target_debug_print_target_waitkind): New. * target-delegates.c: Re-generate. Change-Id: I5421a542f2e19100a22b74cc333d2b235d0de3c8
2021-07-13Fix detach with target remote (PR gdb/28080)Pedro Alves1-0/+6
Commit 408f66864a1a823591b26420410c982174c239a2 ("detach in all-stop with threads running") regressed "detach" with "target remote": (gdb) detach Detaching from program: target:/any/program, process 3671843 Detaching from process 3671843 Ending remote debugging. [Inferior 1 (process 3671843) detached] In main terminate called after throwing an instance of 'gdb_exception_error' Aborted (core dumped) Here's the exception above being thrown: (top-gdb) bt #0 throw_error (error=TARGET_CLOSE_ERROR, fmt=0x555556035588 "Remote connection closed") at src/gdbsupport/common-exceptions.cc:222 #1 0x0000555555bbaa46 in remote_target::readchar (this=0x555556a11040, timeout=10000) at src/gdb/remote.c:9440 #2 0x0000555555bbb9e5 in remote_target::getpkt_or_notif_sane_1 (this=0x555556a11040, buf=0x555556a11058, forever=0, expecting_notif=0, is_notif=0x0) at src/gdb/remote.c:9928 #3 0x0000555555bbbda9 in remote_target::getpkt_sane (this=0x555556a11040, buf=0x555556a11058, forever=0) at src/gdb/remote.c:10030 #4 0x0000555555bc0e75 in remote_target::remote_hostio_send_command (this=0x555556a11040, command_bytes=13, which_packet=14, remote_errno=0x7fffffffcfd0, attachment=0x0, attachment_len=0x0) at src/gdb/remote.c:12137 #5 0x0000555555bc1b6c in remote_target::remote_hostio_close (this=0x555556a11040, fd=8, remote_errno=0x7fffffffcfd0) at src/gdb/remote.c:12455 #6 0x0000555555bc1bb4 in remote_target::fileio_close (During symbol reading: .debug_line address at offset 0x64f417 is 0 [in module build/gdb/gdb] this=0x555556a11040, fd=8, remote_errno=0x7fffffffcfd0) at src/gdb/remote.c:12462 #7 0x0000555555c9274c in target_fileio_close (fd=3, target_errno=0x7fffffffcfd0) at src/gdb/target.c:3365 #8 0x000055555595a19d in gdb_bfd_iovec_fileio_close (abfd=0x555556b9f8a0, stream=0x555556b11530) at src/gdb/gdb_bfd.c:439 #9 0x0000555555e09e3f in opncls_bclose (abfd=0x555556b9f8a0) at src/bfd/opncls.c:599 #10 0x0000555555e0a2c7 in bfd_close_all_done (abfd=0x555556b9f8a0) at src/bfd/opncls.c:847 #11 0x0000555555e0a27a in bfd_close (abfd=0x555556b9f8a0) at src/bfd/opncls.c:814 #12 0x000055555595a9d3 in gdb_bfd_close_or_warn (abfd=0x555556b9f8a0) at src/gdb/gdb_bfd.c:626 #13 0x000055555595ad29 in gdb_bfd_unref (abfd=0x555556b9f8a0) at src/gdb/gdb_bfd.c:715 #14 0x0000555555ae4730 in objfile::~objfile (this=0x555556515540, __in_chrg=<optimized out>) at src/gdb/objfiles.c:573 #15 0x0000555555ae955a in std::_Sp_counted_ptr<objfile*, (__gnu_cxx::_Lock_policy)2>::_M_dispose (this=0x555556c20db0) at /usr/include/c++/9/bits/shared_ptr_base.h:377 #16 0x000055555572b7c8 in std::_Sp_counted_base<(__gnu_cxx::_Lock_policy)2>::_M_release (this=0x555556c20db0) at /usr/include/c++/9/bits/shared_ptr_base.h:155 #17 0x00005555557263c3 in std::__shared_count<(__gnu_cxx::_Lock_policy)2>::~__shared_count (this=0x555556bf0588, __in_chrg=<optimized out>) at /usr/include/c++/9/bits/shared_ptr_base.h:730 #18 0x0000555555ae745e in std::__shared_ptr<objfile, (__gnu_cxx::_Lock_policy)2>::~__shared_ptr (this=0x555556bf0580, __in_chrg=<optimized out>) at /usr/include/c++/9/bits/shared_ptr_base.h:1169 #19 0x0000555555ae747e in std::shared_ptr<objfile>::~shared_ptr (this=0x555556bf0580, __in_chrg=<optimized out>) at /usr/include/c++/9/bits/shared_ptr.h:103 #20 0x0000555555b1c1dc in __gnu_cxx::new_allocator<std::_List_node<std::shared_ptr<objfile> > >::destroy<std::shared_ptr<objfile> > (this=0x5555564cdd60, __p=0x555556bf0580) at /usr/include/c++/9/ext/new_allocator.h:153 #21 0x0000555555b1bb1d in std::allocator_traits<std::allocator<std::_List_node<std::shared_ptr<objfile> > > >::destroy<std::shared_ptr<objfile> > (__a=..., __p=0x555556bf0580) at /usr/include/c++/9/bits/alloc_traits.h:497 #22 0x0000555555b1b73e in std::__cxx11::list<std::shared_ptr<objfile>, std::allocator<std::shared_ptr<objfile> > >::_M_erase (this=0x5555564cdd60, __position=std::shared_ptr<objfile> (expired, weak count 1) = {get() = 0x555556515540}) at /usr/include/c++/9/bits/stl_list.h:1921 #23 0x0000555555b1afeb in std::__cxx11::list<std::shared_ptr<objfile>, std::allocator<std::shared_ptr<objfile> > >::erase (this=0x5555564cdd60, __position=std::shared_ptr<objfile> (expired, weak count 1) = {get() = 0x555556515540}) at /usr/include/c++/9/bits/list.tcc:158 #24 0x0000555555b19576 in program_space::remove_objfile (this=0x5555564cdd20, objfile=0x555556515540) at src/gdb/progspace.c:210 #25 0x0000555555ae4502 in objfile::unlink (this=0x555556515540) at src/gdb/objfiles.c:487 #26 0x0000555555ae5a12 in objfile_purge_solibs () at src/gdb/objfiles.c:875 #27 0x0000555555c09686 in no_shared_libraries (ignored=0x0, from_tty=1) at src/gdb/solib.c:1236 #28 0x00005555559e3f5f in detach_command (args=0x0, from_tty=1) at src/gdb/infcmd.c:2769 So frame #28 already detached the remote process, and then we're purging the shared libraries. GDB had opened remote shared libraries via the target: sysroot, so it tries closing them. GDBserver is tearing down already, so remote communication breaks down and we close the remote target and throw TARGET_CLOSE_ERROR. Note frame #14: #14 0x0000555555ae4730 in objfile::~objfile (this=0x555556515540, __in_chrg=<optimized out>) at src/gdb/objfiles.c:573 That's a dtor, thus noexcept. That's the reason for the std::terminate. Stepping back a bit, why do we still have open remote files if we've managed to detach already, and, we're debugging with "target remote"? The reason is that commit 408f66864a1a823591b26420410c982174c239a2 makes detach_command hold a reference to the target, so the remote target won't be finally closed until frame #28 returns. It's closing the target that invalidates target file I/O handles. This commit fixes the issue by not relying on target_close to invalidate the target file I/O handles, instead invalidate them immediately in remote_unpush_target. So when GDB purges the solibs, and we end up in target_fileio_close (frame #7 above), there's nothing to do, and we don't try to talk with the remote target anymore. The regression isn't seen when testing with --target_board=native-gdbserver, because that does "set sysroot" to disable the "target:" sysroot, for test run speed reasons. So this commit adds a testcase that explicitly tests detach with "set sysroot target:". gdb/ChangeLog: yyyy-mm-dd Pedro Alves <pedro@palves.net> PR gdb/28080 * remote.c (remote_unpush_target): Invalidate file I/O target handles. * target.c (fileio_handles_invalidate_target): Make extern. * target.h (fileio_handles_invalidate_target): Declare. gdb/testsuite/ChangeLog: yyyy-mm-dd Pedro Alves <pedro@palves.net> PR gdb/28080 * gdb.base/detach-sysroot-target.exp: New. * gdb.base/detach-sysroot-target.c: New. Reported-By: Jonah Graham <jonah@kichwacoders.com> Change-Id: I851234910172f42a1b30e731161376c344d2727d
2021-05-23[gdb/tdep] Use pid to choose process 64/32-bitnessTom de Vries1-4/+11
In a linux kernel mailing list discussion, it was mentioned that "gdb has this odd thing where it takes the 64-bit vs 32-bit data for the whole process from one thread, and picks the worst possible thread to do it (ie explicitly not even the main thread, ...)" [1]. The picking of the thread is done here in x86_linux_nat_target::read_description: ... /* GNU/Linux LWP ID's are process ID's. */ tid = inferior_ptid.lwp (); if (tid == 0) tid = inferior_ptid.pid (); /* Not a threaded program. */ ... To understand what this code does, let's investigate a scenario in which inferior_ptid.lwp () != inferior_ptid.pid (). Say we start exec jit-attach-pie, identified with pid x. The main thread starts another thread that sleeps, and then the main thread waits for the sleeping thread. So we have two threads, identified with LWP IDs x and x+1: ... PID LWP CMD x x ./jit-attach-pie x x+1 ./jit-attach-pie ... [ The thread with LWP x is known as the thread group leader. ] When attaching to this exec using the pid, gdb does a stop_all_threads which iterates over all the threads, first LWP x, and then LWP x+1. So the state we arrive with at x86_linux_nat_target::read_description is: ... (gdb) p inferior_ptid $1 = {m_pid = x, m_lwp = x+1, m_tid = 0} ... and consequently we probe 64/32-bitness from thread LWP x+1. [ Note that this is different from when gdb doesn't attach but instead launches the exec itself, in which case there's just one thread to begin with, and consequently the probed thread is LWP x. ] According to aforementioned remark, a better choice would have been the main thread, that is, LWP x. This patch implement that choice, by simply doing: ... tid = inferior_ptid.pid (); ... The fact that gdb makes a per-process permanent choice for 64/32-bitness is a problem in itself: each thread can be in either 64 or 32 bit mode, and change forth and back. That is a problem that this patch doesn't fix. Now finally: why does this matter in the context of the linux kernel discussion? The discussion was related to a patch that exposed io_uring threads to user-space. This made it possible that one of those threads would be picked out to select 64/32-bitness. Given that such threads are atypical user-space threads in the sense that they don't return to user-space and don't have a userspace register state, reading their registers returns garbage, and so it could f.i. occur that in a 64-bit process with all normal user-space threads in 64-bit mode, the probing would return 32-bit. It may be that this is worked-around on the kernel side by providing userspace register state in those threads such that current gdb is happy. Nevertheless, it seems prudent to fix this on the gdb size as well. Tested on x86_64-linux. [1] https://lore.kernel.org/io-uring/CAHk-=wh0KoEZXPYMGkfkeVEerSCEF1AiCZSvz9TRrx=Kj74D+Q@mail.gmail.com/ gdb/ChangeLog: 2021-05-23 Tom de Vries <tdevries@suse.de> PR tdep/27822 * target.h (struct target_ops): Mention target_thread_architecture in read_description comment. * x86-linux-nat.c (x86_linux_nat_target::read_description): Use pid to determine if process is 64-bit or 32-bit. * aarch64-linux-nat.c (aarch64_linux_nat_target::read_description): Same. * ppc-linux-nat.c (ppc_linux_nat_target::read_description): Same. * riscv-linux-nat.c (riscv_linux_nat_target::read_description): Same. * s390-linux-nat.c (s390_linux_nat_target::read_description): Same. * arm-linux-nat.c (arm_linux_nat_target::read_description): Same. Likewise, use pid to determine if kernel supports reading VFP registers.
2021-05-13gdb: on exec, delegate pushing / unpushing target and adding thread to ↵Simon Marchi1-6/+13
target_ops::follow_exec On "exec", some targets need to unpush themselves from the inferior, and do some bookkeeping, like forgetting the data associated to the exec'ing inferior. One such example is the thread-db target. It does so in a special case in thread_db_target::wait, just before returning the TARGET_WAITKIND_EXECD event to its caller. We have another such case in the context of rocm-gdb [1], where the "rocm" target is pushed on top of the linux-nat target. When an exec happens, we want to unpush the rocm target from the exec'ing inferior to close some file descriptors that refer to the pre-exec address space and forget about that inferior. We then want to push the target on the inferior in which execution continues, to open the file descriptors for the post-exec address space. I think that a good way to address this cleanly is to do all this in the target_ops::follow_exec implementations. Make the process_stratum_target::follow_exec implementation have the default behavior of pushing itself to the new inferior's target stack (if execution continues in a new inferior) and add the initial thread. remote_target::follow_exec is an example of process target that wants to do a bit more than the default behavior. So it calls process_stratum_target::follow_exec first and does the extra work second. linux-thread-db (a non-process target) implements follow_exec to do some bookeeping (forget about that process' data), before handing down the event down to the process target (which hits process_stratum_target::follow_exec). gdb/ChangeLog: * target.h (struct target_ops) <follow_exec>: Add ptid_t parameter. (target_follow_exec): Likewise. * target.c (target_follow_exec): Add ptid_t parameter. * infrun.c (follow_exec): Adjust call to target_follow_exec, don't push target nor create thread. * linux-thread-db.c (class thread_db_target) <follow_exec>: New. (thread_db_target::wait): Just return on TARGET_WAITKIND_EXECD. (thread_db_target::follow_exec): New. * remote.c (class remote_target) <follow_exec>: Add ptid_t parameter. (remote_target::follow_exec): Call process_stratum_target::follow_exec. * target-delegates.c: Re-generate. Change-Id: I3f96d0ba3ea0dde6540b7e1b4d5cdb01635088c8
2021-05-13gdb: call target_follow_exec when "set follow-exec-mode" is "same"Simon Marchi1-2/+5
target_follow_exec is currently only called in the "follow-exec-mode == new" branch of follow_exec, not the "follow-exec-mode == same" branch. I think it would make sense to call it regardless of the mode to let targets do some necessary handling. This is needed in the context of rocm-gdb [1], where a target is pushed on top of the linux-nat target. On exec, it needs to do some bookkeeping, close some file descriptors / handles that were related to the process pre-exec and open some new ones for the process post-exec. However, by looking at the only in-tree implementation of target_ops::follow_exec, remote_target::follow_exec, I found that it would be useful for the extended-remote target too, to align its behavior with native debugging (although I think that behavior is not very user-friendly, see PR 27745 [2]). Using two programs, one (let's call it "execer") that execs the other (let's call it "execee"), with native: $ ./gdb -q -nx --data-directory=data-directory ./execer Reading symbols from ./execer... (gdb) r Starting program: /home/simark/build/binutils-gdb/gdb/execer I am execer process 1495622 is executing new program: /home/simark/build/binutils-gdb/gdb/execee I am execee [Inferior 1 (process 1495622) exited normally] (gdb) r Starting program: /home/simark/build/binutils-gdb/gdb/execee I am execee [Inferior 1 (process 1495626) exited normally] And now with gdbserver (some irrelevant output lines removed for brevity): $ ./gdbserver --once --multi :1234 ... $ ./gdb -q -nx --data-directory=data-directory ./execer -ex "set remote exec-file /home/simark/build/binutils-gdb/gdb/execer" -ex "tar ext :1234" Reading symbols from ./execer... Remote debugging using :1234 (gdb) r Starting program: /home/simark/build/binutils-gdb/gdb/execer process 1495724 is executing new program: /home/simark/build/binutils-gdb/gdb/execee [Inferior 1 (process 1495724) exited normally] (gdb) r `target:/home/simark/build/binutils-gdb/gdb/execee' has disappeared; keeping its symbols. Starting program: target:/home/simark/build/binutils-gdb/gdb/execee warning: Build ID mismatch between current exec-file target:/home/simark/build/binutils-gdb/gdb/execee and automatically determined exec-file target:/home/simark/build/binutils-gdb/gdb/execer exec-file-mismatch handling is currently "ask" Reading /home/simark/build/binutils-gdb/gdb/execer from remote target... Load new symbol table from "target:/home/simark/build/binutils-gdb/gdb/execer"? (y or n) When handling the exec, GDB updates the exec-file of the inferior to be the execee. This means that a subsequent "run" will run the execee, not the original executable (execer). remote_target::follow_exec is meant to update the "remote exec-file", which is the file on the remote system that will be executed if you "run" the inferior, to the execee as well. However, this is not called when follow-exec-mode is same, because target_follow_exec is not called in this branch. As a result, GDB thinks the inferior is executing execee but the remote side is really executing execer, hence the mismatch message. By calling target_follow_exec in the "same" branch of the follow_exec function, we ensure that everybody agrees, and we get the same behavior with the extended-remote target as we get with the native target, the execee is executed on the second run: $ ./gdbserver --once --multi :1234 ... $ ./gdb -q -nx --data-directory=data-directory ./execer -ex "set remote exec-file /home/simark/build/binutils-gdb/gdb/execer" -ex "tar ext :1234" Reading symbols from ./execer... Remote debugging using :1234 (gdb) r Starting program: /home/simark/build/binutils-gdb/gdb/execer process 1501445 is executing new program: /home/simark/build/binutils-gdb/gdb/execee [Inferior 1 (process 1501445) exited normally] (gdb) r `target:/home/simark/build/binutils-gdb/gdb/execee' has disappeared; keeping its symbols. Starting program: target:/home/simark/build/binutils-gdb/gdb/execee [Inferior 1 (process 1501447) exited normally] (gdb) This scenario is tested in gdb.base/foll-exec-mode.exp, and in fact this patch fixes the test for me when using --target_board=native-extended-gdbserver. gdb/ChangeLog: * infrun.c (follow_exec): Call target_follow_fork when follow-exec-mode is same. * target.h (target_follow_fork): Improve doc. [1] https://github.com/ROCm-Developer-Tools/ROCgdb [2] https://sourceware.org/bugzilla/show_bug.cgi?id=27745 Change-Id: I4ee84a875e39bf3f8eaf3e6789a4bfe23a2a430e
2021-04-07gdb: make target_ops::follow_fork return voidSimon Marchi1-5/+3
I noticed that all implementations return false, so target_ops::follow_fork doesn't really need to return a value. Change it to return void. gdb/ChangeLog: * target.h (struct target_ops) <follow_fork>: Return void. (target_follow_fork): Likewise. * target.c (default_follow_fork): Likewise. (target_follow_fork): Likewise. * infrun.c (follow_fork_inferior): Adjust. * fbsd-nat.h (class fbsd_nat_target) <follow_fork>: Return void. * fbsd-nat.c (fbsd_nat_target:::follow_fork): Likewise. * linux-nat.h (class linux_nat_target) <follow_fork>: Likewise. * linux-nat.c (linux_nat_target::follow_fork): Return void. * obsd-nat.h (class obsd_nat_target) <follow_fork>: Return void. * obsd-nat.c (obsd_nat_target::follow_fork): Likewise. * remote.c (class remote_target) <follow_fork>: Likewise. (remote_target::follow_fork): Likewise. * target-delegates.c: Re-generate. Change-Id: If908c2f68b29fa275be2b0b9deb41e4c6a1b7879
2021-03-26gdb: defer commit resume until all available events are consumedSimon Marchi1-0/+14
Rationale --------- Let's say you have multiple threads hitting a conditional breakpoint at the same time, and all of these are going to evaluate to false. All these threads will need to be resumed. Currently, GDB fetches one target event (one SIGTRAP representing the breakpoint hit) and decides that the thread should be resumed. It calls resume and commit_resume immediately. It then fetches the second target event, and does the same, until it went through all threads. The result is therefore something like: - consume event for thread A - resume thread A - commit resume (affects thread A) - consume event for thread B - resume thread B - commit resume (affects thread B) - consume event for thread C - resume thread C - commit resume (affects thread C) For targets where it's beneficial to group resumptions requests (most likely those that implement target_ops::commit_resume), it would be much better to have: - consume event for thread A - resume thread A - consume event for thread B - resume thread B - consume event for thread C - resume thread C - commit resume (affects threads A, B and C) Implementation details ---------------------- To achieve this, this patch adds another check in maybe_set_commit_resumed_all_targets to avoid setting the commit-resumed flag of targets that readily have events to provide to infrun. To determine if a target has events readily available to report, this patch adds an `has_pending_events` target_ops method. The method returns a simple bool to say whether or not it has pending events to report. Testing ======= To test this, I start GDBserver with a program that spawns multiple threads: $ ../gdbserver/gdbserver --once :1234 ~/src/many-threads-stepping-over-breakpoints/many-threads-stepping-over-breakpoints I then connect with GDB and install a conditional breakpoint that always evaluates to false (and force the evaluation to be done by GDB): $ ./gdb -nx --data-directory=data-directory \ /home/simark/src/many-threads-stepping-over-breakpoints/many-threads-stepping-over-breakpoints \ -ex "set breakpoint condition-evaluation host" \ -ex "set pag off" \ -ex "set confirm off" \ -ex "maint set target-non-stop on" \ -ex "tar rem :1234" \ -ex "tb main" \ -ex "b 13 if 0" \ -ex c \ -ex "set debug infrun" \ -ex "set debug remote 1" \ -ex "set debug displaced" I then do "continue" and look at the log. The remote target receives a bunch of stop notifications for all threads that have hit the breakpoint. infrun consumes and processes one event, decides it should not cause a stop, prepares a displaced step, after which we should see: [infrun] maybe_set_commit_resumed_all_process_targets: not requesting commit-resumed for target remote, target has pending events Same for a second thread (since we have 2 displaced step buffers). For the following threads, their displaced step is deferred since there are no more buffers available. After consuming the last event the remote target has to offer, we get: [infrun] maybe_set_commit_resumed_all_process_targets: enabling commit-resumed for target remote [infrun] maybe_call_commit_resumed_all_process_targets: calling commit_resumed for target remote [remote] Sending packet: $vCont;s:p14d16b.14d1b1;s:p14d16b.14d1b2#55 [remote] Packet received: OK Without the patch, there would have been one vCont;s just after each prepared displaced step. gdb/ChangeLog: yyyy-mm-dd Simon Marchi <simon.marchi@efficios.com> Pedro Alves <pedro@palves.net> * async-event.c (async_event_handler_marked): New. * async-event.h (async_event_handler_marked): Declare. * infrun.c (maybe_set_commit_resumed_all_targets): Switch to inferior before calling target method. Don't commit-resumed if target_has_pending_events is true. * remote.c (remote_target::has_pending_events): New. * target-delegates.c: Regenerate. * target.c (target_has_pending_events): New. * target.h (target_ops::has_pending_events): New target method. (target_has_pending_events): New. Change-Id: I18112ba19a1ff4986530c660f530d847bb4a1f1d
2021-03-26gdb: generalize commit_resume, avoid commit-resuming when threads have ↵Simon Marchi1-18/+13
pending statuses The rationale for this patch comes from the ROCm port [1], the goal being to reduce the number of back and forths between GDB and the target when doing successive operations. I'll start with explaining the rationale and then go over the implementation. In the ROCm / GPU world, the term "wave" is somewhat equivalent to a "thread" in GDB. So if you read if from a GPU stand point, just s/thread/wave/. ROCdbgapi, the library used by GDB [2] to communicate with the GPU target, gives the illusion that it's possible for the debugger to control (start and stop) individual threads. But in reality, this is not how it works. Under the hood, all threads of a queue are controlled as a group. To stop one thread in a group of running ones, the state of all threads is retrieved from the GPU, all threads are destroyed, and all threads but the one we want to stop are re-created from the saved state. The net result, from the point of view of GDB, is that the library stopped one thread. The same thing goes if we want to resume one thread while others are running: the state of all running threads is retrieved from the GPU, they are all destroyed, and they are all re-created, including the thread we want to resume. This leads to some inefficiencies when combined with how GDB works, here are two examples: - Stopping all threads: because the target operates in non-stop mode, when the user interface mode is all-stop, GDB must stop all threads individually when presenting a stop. Let's suppose we have 1000 threads and the user does ^C. GDB asks the target to stop one thread. Behind the scenes, the library retrieves 1000 thread states and restores the 999 others still running ones. GDB asks the target to stop another one. The target retrieves 999 thread states and restores the 998 remaining ones. That means that to stop 1000 threads, we did 1000 back and forths with the GPU. It would have been much better to just retrieve the states once and stop there. - Resuming with pending events: suppose the 1000 threads hit a breakpoint at the same time. The breakpoint is conditional and evaluates to true for the first thread, to false for all others. GDB pulls one event (for the first thread) from the target, decides that it should present a stop, so stops all threads using stop_all_threads. All these other threads have a breakpoint event to report, which is saved in `thread_info::suspend::waitstatus` for later. When the user does "continue", GDB resumes that one thread that did hit the breakpoint. It then processes the pending events one by one as if they just arrived. It picks one, evaluates the condition to false, and resumes the thread. It picks another one, evaluates the condition to false, and resumes the thread. And so on. In between each resumption, there is a full state retrieval and re-creation. It would be much nicer if we could wait a little bit before sending those threads on the GPU, until it processed all those pending events. To address this kind of performance issue, ROCdbgapi has a concept called "forward progress required", which is a boolean state that allows its user (i.e. GDB) to say "I'm doing a bunch of operations, you can hold off putting the threads on the GPU until I'm done" (the "forward progress not required" state). Turning forward progress back on indicates to the library that all threads that are supposed to be running should now be really running on the GPU. It turns out that GDB has a similar concept, though not as general, commit_resume. One difference is that commit_resume is not stateful: the target can't look up "does the core need me to schedule resumed threads for execution right now". It is also specifically linked to the resume method, it is not used in other contexts. The target accumulates resumption requests through target_ops::resume calls, and then commits those resumptions when target_ops::commit_resume is called. The target has no way to check if it's ok to leave resumed threads stopped in other target methods. To bridge the gap, this patch generalizes the commit_resume concept in GDB to match the forward progress concept of ROCdbgapi. The current name (commit_resume) can be interpreted as "commit the previous resume calls". I renamed the concept to "commit_resumed", as in "commit the threads that are resumed". In the new version, we have two things: - the commit_resumed_state field in process_stratum_target: indicates whether GDB requires target stacks using this target to have resumed threads committed to the execution target/device. If false, an execution target is allowed to leave resumed threads un-committed at the end of whatever method it is executing. - the commit_resumed target method: called when commit_resumed_state transitions from false to true. While commit_resumed_state was false, the target may have left some resumed threads un-committed. This method being called tells it that it should commit them back to the execution device. Let's take the "Stopping all threads" scenario from above and see how it would work with the ROCm target with this change. Before stopping all threads, GDB would set the target's commit_resumed_state field to false. It would then ask the target to stop the first thread. The target would retrieve all threads' state from the GPU and mark that one as stopped. Since commit_resumed_state is false, it leaves all the other threads (still resumed) stopped. GDB would then proceed to call target_stop for all the other threads. Since resumed threads are not committed, this doesn't do any back and forth with the GPU. To simplify the implementation of targets, this patch makes it so that when calling certain target methods, the contract between the core and the targets guarantees that commit_resumed_state is false. This way, the target doesn't need two paths, one for commit_resumed_state == true and one for commit_resumed_state == false. It can just assert that commit_resumed_state is false and work with that assumption. This also helps catch places where we forgot to disable commit_resumed_state before calling the method, which represents a probable optimization opportunity. The commit adds assertions in the target method wrappers (target_resume and friends) to have some confidence that this contract between the core and the targets is respected. The scoped_disable_commit_resumed type is used to disable the commit resumed state of all process targets on construction, and selectively re-enable it on destruction (see below for criteria). Note that it only sets the process_stratum_target::commit_resumed_state flag. A subsequent call to maybe_call_commit_resumed_all_targets is necessary to call the commit_resumed method on all target stacks with process targets that got their commit_resumed_state flag turned back on. This separation is because we don't want to call the commit_resumed methods in scoped_disable_commit_resumed's destructor, as they may throw. On destruction, commit-resumed is not re-enabled for a given target if: 1. this target has no threads resumed, or 2. this target has at least one resumed thread with a pending status known to the core (saved in thread_info::suspend::waitstatus). The first point is not technically necessary, because a proper commit_resumed implementation would be a no-op if the target has no resumed threads. But since we have a flag do to a quick check, it shouldn't hurt. The second point is more important: together with the scoped_disable_commit_resumed instance added in fetch_inferior_event, it makes it so the "Resuming with pending events" described above is handled efficiently. Here's what happens in that case: 1. The user types "continue". 2. Upon destruction, the scoped_disable_commit_resumed in the `proceed` function does not enable commit-resumed, as it sees some threads have pending statuses. 3. fetch_inferior_event is called to handle another event, the breakpoint hit evaluates to false, and that thread is resumed. Because there are still more threads with pending statuses, the destructor of scoped_disable_commit_resumed in fetch_inferior_event still doesn't enable commit-resumed. 4. Rinse and repeat step 3, until the last pending status is handled by fetch_inferior_event. In that case, scoped_disable_commit_resumed's destructor sees there are no more threads with pending statues, so it asks the target to commit resumed threads. This allows us to avoid all unnecessary back and forths, there is a single commit_resumed call once all pending statuses are processed. This change required remote_target::remote_stop_ns to learn how to handle stopping threads that were resumed but pending vCont. The simplest example where that happens is when using the remote target in all-stop, but with "maint set target-non-stop on", to force it to operate in non-stop mode under the hood. If two threads hit a breakpoint at the same time, GDB will receive two stop replies. It will present the stop for one thread and save the other one in thread_info::suspend::waitstatus. Before this patch, when doing "continue", GDB first resumes the thread without a pending status: Sending packet: $vCont;c:p172651.172676#f3 It then consumes the pending status in the next fetch_inferior_event call: [infrun] do_target_wait_1: Using pending wait status status->kind = stopped, signal = GDB_SIGNAL_TRAP for Thread 1517137.1517137. [infrun] target_wait (-1.0.0, status) = [infrun] 1517137.1517137.0 [Thread 1517137.1517137], [infrun] status->kind = stopped, signal = GDB_SIGNAL_TRAP It then realizes it needs to stop all threads to present the stop, so stops the thread it just resumed: [infrun] stop_all_threads: Thread 1517137.1517137 not executing [infrun] stop_all_threads: Thread 1517137.1517174 executing, need stop remote_stop called Sending packet: $vCont;t:p172651.172676#04 This is an unnecessary resume/stop. With this patch, we don't commit resumed threads after proceeding, because of the pending status: [infrun] maybe_commit_resumed_all_process_targets: not requesting commit-resumed for target extended-remote, a thread has a pending waitstatus When GDB handles the pending status and stop_all_threads runs, we stop a resumed but pending vCont thread: remote_stop_ns: Enqueueing phony stop reply for thread pending vCont-resume (1520940, 1520976, 0) That thread was never actually resumed on the remote stub / gdbserver, so we shouldn't send a packet to the remote side asking to stop the thread. Note that there are paths that resume the target and then do a synchronous blocking wait, in sort of nested event loop, via wait_sync_command_done. For example, inferior function calls, or any run control command issued from a breakpoint command list. We handle that making wait_sync_command_one a "sync" point -- force forward progress, or IOW, force-enable commit-resumed state. gdb/ChangeLog: yyyy-mm-dd Simon Marchi <simon.marchi@efficios.com> Pedro Alves <pedro@palves.net> * infcmd.c (run_command_1, attach_command, detach_command) (interrupt_target_1): Use scoped_disable_commit_resumed. * infrun.c (do_target_resume): Remove target_commit_resume call. (commit_resume_all_targets): Remove. (maybe_set_commit_resumed_all_targets): New. (maybe_call_commit_resumed_all_targets): New. (enable_commit_resumed): New. (scoped_disable_commit_resumed::scoped_disable_commit_resumed) (scoped_disable_commit_resumed::~scoped_disable_commit_resumed) (scoped_disable_commit_resumed::reset) (scoped_disable_commit_resumed::reset_and_commit) (scoped_enable_commit_resumed::scoped_enable_commit_resumed) (scoped_enable_commit_resumed::~scoped_enable_commit_resumed): New. (proceed): Use scoped_disable_commit_resumed and maybe_call_commit_resumed_all_targets. (fetch_inferior_event): Use scoped_disable_commit_resumed. * infrun.h (struct scoped_disable_commit_resumed): New. (maybe_call_commit_resumed_all_process_targets): New. (struct scoped_enable_commit_resumed): New. * mi/mi-main.c (exec_continue): Use scoped_disable_commit_resumed. * process-stratum-target.h (class process_stratum_target): <commit_resumed_state>: New. * record-full.c (record_full_wait_1): Change commit_resumed_state around calling commit_resumed. * remote.c (class remote_target) <commit_resume>: Rename to... <commit_resumed>: ... this. (struct stop_reply): Move up. (remote_target::commit_resume): Rename to... (remote_target::commit_resumed): ... this. Check if there is any thread pending vCont resume. (remote_target::remote_stop_ns): Generate stop replies for resumed but pending vCont threads. (remote_target::wait_ns): Add gdb_assert. * target-delegates.c: Regenerate. * target.c (target_wait, target_resume): Assert that the current process_stratum target isn't in commit-resumed state. (defer_target_commit_resume): Remove. (target_commit_resume): Remove. (target_commit_resumed): New. (make_scoped_defer_target_commit_resume): Remove. (target_stop): Assert that the current process_stratum target isn't in commit-resumed state. * target.h (struct target_ops) <commit_resume>: Rename to ... <commit_resumed>: ... this. (target_commit_resume): Remove. (target_commit_resumed): New. (make_scoped_defer_target_commit_resume): Remove. * top.c (wait_sync_command_done): Use scoped_enable_commit_resumed. [1] https://github.com/ROCm-Developer-Tools/ROCgdb/ [2] https://github.com/ROCm-Developer-Tools/ROCdbgapi Change-Id: I836135531a29214b21695736deb0a81acf8cf566
2021-03-24gdb: remove current_top_target functionSimon Marchi1-5/+0
The current_top_target function is a hidden dependency on the current inferior. Since I'd like to slowly move towards reducing our dependency on the global current state, remove this function and make callers use current_inferior ()->top_target () There is no expected change in behavior, but this one step towards making those callers use the inferior from their context, rather than refer to the global current inferior. gdb/ChangeLog: * target.h (current_top_target): Remove, make callers use the current inferior instead. * target.c (current_top_target): Remove. Change-Id: Iccd457036f84466cdaa3865aa3f9339a24ea001d
2021-03-24gdb: move all "current target" wrapper implementations to target.cSimon Marchi1-185/+111
The following patch removes the current_top_target function, replacing uses with `current_inferior ()->top_target ()`. This is a problem for uses in target.h, because they don't have access to the current_inferior function and the inferior structure: target.h can't include inferior.h, otherwise that would make a cyclic inclusion. Avoid this by moving all implementations of the wrappers that call target methods with the current target to target.c. Many of them are changed from a macro to a function, which is an improvement for readability and debuggability, IMO. target_shortname and target_longname were not function-like macros, so a few adjustments are needed. gdb/ChangeLog: * target.h (target_shortname): Change to function declaration. (target_longname): Likewise. (target_attach_no_wait): Likewise. (target_post_attach): Likewise. (target_prepare_to_store): Likewise. (target_supports_enable_disable_tracepoint): Likewise. (target_supports_string_tracing): Likewise. (target_supports_evaluation_of_breakpoint_conditions): Likewise. (target_supports_dumpcore): Likewise. (target_dumpcore): Likewise. (target_can_run_breakpoint_commands): Likewise. (target_files_info): Likewise. (target_post_startup_inferior): Likewise. (target_insert_fork_catchpoint): Likewise. (target_remove_fork_catchpoint): Likewise. (target_insert_vfork_catchpoint): Likewise. (target_remove_vfork_catchpoint): Likewise. (target_insert_exec_catchpoint): Likewise. (target_remove_exec_catchpoint): Likewise. (target_set_syscall_catchpoint): Likewise. (target_rcmd): Likewise. (target_can_lock_scheduler): Likewise. (target_can_async_p): Likewise. (target_is_async_p): Likewise. (target_execution_direction): Likewise. (target_extra_thread_info): Likewise. (target_pid_to_exec_file): Likewise. (target_thread_architecture): Likewise. (target_find_memory_regions): Likewise. (target_make_corefile_notes): Likewise. (target_get_bookmark): Likewise. (target_goto_bookmark): Likewise. (target_stopped_by_watchpoint): Likewise. (target_stopped_by_sw_breakpoint): Likewise. (target_supports_stopped_by_sw_breakpoint): Likewise. (target_stopped_by_hw_breakpoint): Likewise. (target_supports_stopped_by_hw_breakpoint): Likewise. (target_have_steppable_watchpoint): Likewise. (target_can_use_hardware_watchpoint): Likewise. (target_region_ok_for_hw_watchpoint): Likewise. (target_can_do_single_step): Likewise. (target_insert_watchpoint): Likewise. (target_remove_watchpoint): Likewise. (target_insert_hw_breakpoint): Likewise. (target_remove_hw_breakpoint): Likewise. (target_can_accel_watchpoint_condition): Likewise. (target_can_execute_reverse): Likewise. (target_get_ada_task_ptid): Likewise. (target_filesystem_is_local): Likewise. (target_trace_init): Likewise. (target_download_tracepoint): Likewise. (target_can_download_tracepoint): Likewise. (target_download_trace_state_variable): Likewise. (target_enable_tracepoint): Likewise. (target_disable_tracepoint): Likewise. (target_trace_start): Likewise. (target_trace_set_readonly_regions): Likewise. (target_get_trace_status): Likewise. (target_get_tracepoint_status): Likewise. (target_trace_stop): Likewise. (target_trace_find): Likewise. (target_get_trace_state_variable_value): Likewise. (target_save_trace_data): Likewise. (target_upload_tracepoints): Likewise. (target_upload_trace_state_variables): Likewise. (target_get_raw_trace_data): Likewise. (target_get_min_fast_tracepoint_insn_len): Likewise. (target_set_disconnected_tracing): Likewise. (target_set_circular_trace_buffer): Likewise. (target_set_trace_buffer_size): Likewise. (target_set_trace_notes): Likewise. (target_get_tib_address): Likewise. (target_set_permissions): Likewise. (target_static_tracepoint_marker_at): Likewise. (target_static_tracepoint_markers_by_strid): Likewise. (target_traceframe_info): Likewise. (target_use_agent): Likewise. (target_can_use_agent): Likewise. (target_augmented_libraries_svr4_read): Likewise. (target_log_command): Likewise. * target.c (target_shortname): New. (target_longname): New. (target_attach_no_wait): New. (target_post_attach): New. (target_prepare_to_store): New. (target_supports_enable_disable_tracepoint): New. (target_supports_string_tracing): New. (target_supports_evaluation_of_breakpoint_conditions): New. (target_supports_dumpcore): New. (target_dumpcore): New. (target_can_run_breakpoint_commands): New. (target_files_info): New. (target_post_startup_inferior): New. (target_insert_fork_catchpoint): New. (target_remove_fork_catchpoint): New. (target_insert_vfork_catchpoint): New. (target_remove_vfork_catchpoint): New. (target_insert_exec_catchpoint): New. (target_remove_exec_catchpoint): New. (target_set_syscall_catchpoint): New. (target_rcmd): New. (target_can_lock_scheduler): New. (target_can_async_p): New. (target_is_async_p): New. (target_execution_direction): New. (target_extra_thread_info): New. (target_pid_to_exec_file): New. (target_thread_architecture): New. (target_find_memory_regions): New. (target_make_corefile_notes): New. (target_get_bookmark): New. (target_goto_bookmark): New. (target_stopped_by_watchpoint): New. (target_stopped_by_sw_breakpoint): New. (target_supports_stopped_by_sw_breakpoint): New. (target_stopped_by_hw_breakpoint): New. (target_supports_stopped_by_hw_breakpoint): New. (target_have_steppable_watchpoint): New. (target_can_use_hardware_watchpoint): New. (target_region_ok_for_hw_watchpoint): New. (target_can_do_single_step): New. (target_insert_watchpoint): New. (target_remove_watchpoint): New. (target_insert_hw_breakpoint): New. (target_remove_hw_breakpoint): New. (target_can_accel_watchpoint_condition): New. (target_can_execute_reverse): New. (target_get_ada_task_ptid): New. (target_filesystem_is_local): New. (target_trace_init): New. (target_download_tracepoint): New. (target_can_download_tracepoint): New. (target_download_trace_state_variable): New. (target_enable_tracepoint): New. (target_disable_tracepoint): New. (target_trace_start): New. (target_trace_set_readonly_regions): New. (target_get_trace_status): New. (target_get_tracepoint_status): New. (target_trace_stop): New. (target_trace_find): New. (target_get_trace_state_variable_value): New. (target_save_trace_data): New. (target_upload_tracepoints): New. (target_upload_trace_state_variables): New. (target_get_raw_trace_data): New. (target_get_min_fast_tracepoint_insn_len): New. (target_set_disconnected_tracing): New. (target_set_circular_trace_buffer): New. (target_set_trace_buffer_size): New. (target_set_trace_notes): New. (target_get_tib_address): New. (target_set_permissions): New. (target_static_tracepoint_marker_at): New. (target_static_tracepoint_markers_by_strid): New. (target_traceframe_info): New. (target_use_agent): New. (target_can_use_agent): New. (target_augmented_libraries_svr4_read): New. (target_log_command): New. * bfin-tdep.c (bfin_sw_breakpoint_from_kind): Adjust. * infrun.c (set_schedlock_func): Adjust. * mi/mi-main.c (exec_reverse_continue): Adjust. * reverse.c (exec_reverse_once): Adjust. * sh-tdep.c (sh_sw_breakpoint_from_kind): Adjust. * tui/tui-stack.c (tui_locator_window::make_status_line): Adjust. * remote-sim.c (gdbsim_target::detach): Adjust. (gdbsim_target::files_info): Adjust. Change-Id: I72ef56e9a25adeb0b91f1ad05e34c89f77ebeaa8
2021-03-24New target methods for memory tagging supportLuis Machado1-0/+41
This patch starts adding some of the generic pieces to accomodate memory tagging. We have three new target methods: - supports_memory_tagging: Checks if the target supports memory tagging. This defaults to false for targets that don't support memory tagging. - fetch_memtags: Fetches the allocation tags associated with a particular memory range [address, address + length). The default is to return 0 without returning any tags. This should only be called if memory tagging is supported. - store_memtags: Stores a set of allocation tags for a particular memory range [address, address + length). The default is to return 0. This should only be called if memory tagging is supported. gdb/ChangeLog: 2021-03-24 Luis Machado <luis.machado@linaro.org> * remote.c (remote_target) <supports_memory_tagging>: New method override. <fetch_memtags>: New method override. <store_memtags>: New method override. (remote_target::supports_memory_tagging): New method. (remote_target::fetch_memtags): New method. (remote_target::store_memtags): New method. * target-delegates.c: Regenerate. * target.h (struct target_ops) <supports_memory_tagging>: New virtual method. <fetch_memtags>: New virtual method. <store_memtags>: New virtual method. (target_supports_memory_tagging): Define. (target_fetch_memtags): Define. (target_store_memtags): Define. * target-debug.h (target_debug_print_size_t) (target_debug_print_const_gdb_byte_vector_r) (target_debug_print_gdb_byte_vector_r): New functions.
2021-03-23gdb: remote target_longnameSimon Marchi1-1/+0
I noticed it was unused. gdb/ChangeLog: * target.h (target_longname): Remove. Change-Id: Id4f514ea038a6d8d40e11179db587b11793cbbd8
2021-03-23gdb: remove target_is_pushed free functionSimon Marchi1-2/+0
Same principle as the previous patches. gdb/ChangeLog: * target.h (target_is_pushed): Remove, update callers to use inferior::target_is_pushed instead. * target.c (target_is_pushed): Remove. Change-Id: I9862e6205acc65672da807cbe4b46cde009e7b9d
2021-03-23gdb: remove push_target free functionsSimon Marchi1-5/+0
Same as the previous patch, but for the push_target functions. The implementation of the move variant is moved to a new overload of inferior::push_target. gdb/ChangeLog: * target.h (push_target): Remove, update callers to use inferior::push_target. * target.c (push_target): Remove. * inferior.h (class inferior) <push_target>: New overload. Change-Id: I5a95496666278b8f3965e5e8aecb76f54a97c185
2021-03-23gdb: remove unpush_target free functionSimon Marchi1-6/+1
unpush_target unpushes the passed-in target from the current inferior's target stack. Calling it is therefore an implicit dependency on the current global inferior. Remove that function and make the callers use the inferior::unpush_target method directly. This sometimes allows using the inferior from the context rather than the global current inferior. target_unpusher::operator() now needs to be implemented in target.c, otherwise target.h and inferior.h both need to include each other, and that wouldn't work. gdb/ChangeLog: * target.h (unpush_target): Remove, update all callers to use `inferior::unpush_target` instead. (struct target_unpusher) <operator()>: Just declare. * target.c (unpush_target): Remove. (target_unpusher::operator()): New. Change-Id: Ia5172dfb3f373e0a75b991885b50322ca2142a8c
2021-02-24gdb: move get_section_table from exec_target to dummy_targetAndrew Burgess1-1/+5
The only target that implements target_ops::get_section_table in a meaningful way is exec_target. This target calls back into the program space to return the current global section_table. The global section table is populated whenever the user provides GDB with an executable, or when a symbol file is loaded, e.g. when a dynamic library is loaded, or when the user does add-symbol-file. I recently ran into a situation where a user, debugging a remote target, was not supplying GDB with a main executable at all. Instead the user attached to the target then did add-symbol-file, and then proceeded to debug the target. This works fine, but it was noticed that even when trust-readonly-sections was on GDB was still accessing the target to get the contents of readonly sections. The problem is that by not providing an executable there was no exec_target in the target stack, and so when GDB calls the target_ops::get_section_table function GDB ends up in dummy_target::get_section_table, which just returns NULL. What I want is that even when GDB doesn't have an exec_target in the target stack, a call to target_ops::get_section_table will still return the section_table from the current program space. When considering how to achieve this my first though was, why is the request for the section table going via the target stack at all? The set of sections loaded is a property of the program space, not the target. This is, after all, why the data is being stored in the program space. So I initially tried changing target_get_section_table so that, instead of calling into the target it just returns current_program_space->target_sections (). This would be fine except for one issue, target_bfd (from bfd-target.c). This code is used from solib-svr4.c to create a temporary target_ops structure that implements two functions target_bfd::xfer_partial and target_bfd::get_section_table. The purpose behind the code is to enable two targets, ppc64 and frv to decode function descriptors from the dynamic linker, based on the non-relocated addresses from within the dynamic linker bfd object. Both of the implemented functions in target_bfd rely on the target_bfd object holding a section table, and the ppc64 target requires that the target_bfd implement ::get_section_table. The frv target doesn't require ::get_section_table, instead it requires the ::xfer_partial. We could in theory change the ppc64 target to use the same approach as frv, however, this would be a bad idea. I believe that the frv target approach is broken. I'll explain: The frv target calls get_target_memory_unsigned to read the function descriptor. The address being read is the non-relocated address read from the dynamic linker in solib-srv4.c:enable_break. Calling get_target_memory_unsigned eventually ends up in target_xfer_partial with an object type of TARGET_OBJECT_RAW_MEMORY. This will then call memory_xfer_check_region. I believe that it is quite possible that a the non-relocated addresses pulled from the dynamic linker could be in a memory region that is not readable, while the relocated addresses are in a readable memory region. If this was ever the case for the frv target then GDB would reject the attempt to read the non-relocated function pointer. In contrast the ppc64 target calls target_section_by_addr, which calls target_get_section_table, which then calls the ::get_section_table function on the target. Thus, when reflecting on target_bfd we see two functions, ::xfer_partial and ::get_section_table. The former is required by the frv target, but that target is (I think) potentially broken. While the latter is required by the ppc64 target, but this forces ::get_section_table to exist as a target_ops member function. So my original plan, have target_get_section_table NOT call a target_ops member function appears to be flawed. My next idea was to remove exec_target::get_section_table, and instead move the implementation into dummy_target::get_section_table. Currently the dummy_target implementation always returns NULL indicating no section table, but plenty of other dummy_target member functions do more than just return null values. So now, dummy_target::get_section_table returns the section table from the current program space. This allows target_bfd to remain unchanged, so ppc64 and frv should not be affected. Making this change removes the requirement for the user to provide an executable, GDB can now always access the section_table, as the dummy_target always exists in the target stack. Finally, there's a test that the target_section table is not empty in the case where the user does add-symbol-file without providing an executable. gdb/ChangeLog: * exec.c (exec_target::get_section_table): Delete member function. (section_table_read_available_memory): Use current_top_target, not just the exec_ops target. * target-delegates.c: Regenerate. * target.c (default_get_section_table): New function. * target.h (target_ops::get_section_table): Change default behaviour to call default_get_section_table. (default_get_section_table): Declare.
2021-02-24gdb: spread a little 'const' through the target_section_table codeAndrew Burgess1-4/+4
The code to access the target section table can be made more const, so lets do that. There should be no user visible changes after this commit. gdb/ChangeLog: * gdb/bfd-target.c (class target_bfd) <get_section_table>: Make return type const. * gdb/exec.c (struct exec_target) <get_section_table>: Likewise. (section_table_read_available_memory): Make local const. (exec_target::xfer_partial): Make local const. (print_section_info): Make parameter const. * gdb/exec.h (print_section_info): Likewise. * gdb/ppc64-tdep.c (ppc64_convert_from_func_ptr_addr): Make local const. * gdb/record-btrace.c (record_btrace_target::xfer_partial): Likewise. * gdb/remote.c (remote_target::remote_xfer_live_readonly_partial): Likewise. * gdb/s390-tdep.c (s390_load): Likewise. * gdb/solib-dsbt.c (scan_dyntag): Likewise. * gdb/solib-svr4.c (scan_dyntag): Likewise. * gdb/target-debug.h (target_debug_print_target_section_table_p): Rename to... (target_debug_print_const_target_section_table_p): ...this. * gdb/target-delegates.c: Regenerate. * gdb/target.c (target_get_section_table): Make return type const. (target_section_by_addr): Likewise. Also make some locals const. (memory_xfer_partial_1): Make some locals const. * gdb/target.h (struct target_ops) <get_section_table>: Make return type const. (target_section_by_addr): Likewise. (target_get_section_table): Likewise.
2021-02-22gdb: push target earlier in procfs_target::attach (PR 27435)Simon Marchi1-0/+14
Since this is a GDB 9 -> 10 regression, I would like to push it to gdb-10-branch. This is a follow-up to: https://sourceware.org/pipermail/gdb-patches/2021-February/176202.html This patch fixes a segfault seen when attaching to a process on Solaris. The steps leading to the segfault are: - procfs_target::attach calls do_attach, at this point the inferior's process slot in the target stack is empty. - do_attach adds a thread with `add_thread (&the_procfs_target, ptid)` - in add_thread_silent, the passed target (&the_procfs_target) is passed to find_inferior_ptid - find_inferior_ptid returns nullptr, as there is no inferior with this ptid that has &the_procfs_target as its process target - the nullptr `inf` is passed to find_thread_ptid, which dereferences it, causing a segfault - back in procfs_target::attach, after do_attach, we push the the_procfs_target on the inferior's target stack, although we never reach this because the segfault happens before. To fix this, I think we need to do the same as is done in inf_ptrace_target::attach: push the target early and unpush it in case the attach fails (and keep it if the attach succeeds). Implement it by moving target_unpush_up to target.h, so it can be re-used here. Make procfs_target::attach use it. Note that just like is mentioned in inf_ptrace_target::attach, we should push the target before calling target_pid_to_str, so that calling target_pid_to_str ends up in procfs_target::pid_to_str. Tested by trying to attach on a process on gcc211 on the gcc compile farm. gdb/ChangeLog: PR gdb/27435 * inf-ptrace.c (struct target_unpusher): Move to target.h. (target_unpush_up): Likewise. * procfs.c (procfs_target::attach): Push target early. Use target_unpush_up to unpush target in case of error. * target.h (struct target_unpusher): Move here. (target_unpush_up): Likewise. Change-Id: I88aff8b20204e1ca1d792e27ac6bc34fc1aa0d52
2021-02-04gdb: make target_is_non_stop_p return boolSimon Marchi1-1/+1
gdb/ChangeLog: * target.c (target_is_non_stop_p): Return bool. * target.h (target_is_non_stop_p): Return bool. Change-Id: Icdb37ffe917798e59b822976794d4b1b7aafd709
2021-02-03detach and breakpoint removalPedro Alves1-0/+7
A following patch will add a testcase that has a number of threads constantly stepping over a breakpoint, and then has GDB detach the process. That testcase sometimes fails with the inferior crashing with SIGTRAP after the detach because of the bug fixed by this patch, when tested with the native target. The problem is that target_detach removes breakpoints from the target immediately, and that does not work with the native GNU/Linux target (and probably no other native target) currently. The test wouldn't fail with this issue when testing against gdbserver, because gdbserver does allow accessing memory while the current thread is running, by transparently pausing all threads temporarily, without GDB noticing. Implementing that in gdbserver was a lot of work, so I'm not looking forward right now to do the same in the native target. Instead, I came up with a simpler solution -- push the breakpoints removal down to the targets. The Linux target conveniently already pauses all threads before detaching them, since PTRACE_DETACH only works with stopped threads, so we move removing breakpoints to after that. Only the remote and GNU/Linux targets support support async execution, so no other target should really need this. gdb/ChangeLog: * linux-nat.c (linux_nat_target::detach): Remove breakpoints here... * remote.c (remote_target::remote_detach_1): ... and here ... * target.c (target_detach): ... instead of here. * target.h (target_ops::detach): Add comment.
2021-01-22gdb: move remote_debug to remote.{h,c}Simon Marchi1-3/+0
remote_debug is currently declared in target.h and defined in top.c. Move them to remote.h and remote.c. Include remote.h in remote-sim.c, as it uses remote_debug. gdb/ChangeLog: * target.h (remote_debug): Move to... * remote.h (remote_debug): ... here. * top.c (remote_debug): Move to... * remote.c (remote_debug): ... here. * remote-sim.c: Include remote.h. Change-Id: Iae632d12ff8900b23eee6b2529d6a3cd339a8caa
2021-01-12gdb: move baud_rate and serial_parity declarations to serial.hSimon Marchi1-6/+0
They are currently in target.h, it would make more sense to have them in serial.h, since they are defined in serial.c. gdb/ChangeLog: * target.h (baud_rate, serial_parity): Move declarations... * serial.h: ... here. * main.c: Include serial.h. * serial.c (baud_rate, serial_parity): Update doc. Change-Id: Idc983c154c80ccc29b07ce68df3483cefe03fb71
2021-01-01Update copyright year range in all GDB filesJoel Brobecker1-1/+1
This commits the result of running gdb/copyright.py as per our Start of New Year procedure... gdb/ChangeLog Update copyright year range in copyright header of all GDB files.
2020-11-02gdb, gdbserver, gdbsupport: fix leading space vs tabs issuesSimon Marchi1-4/+4
Many spots incorrectly use only spaces for indentation (for example, there are a lot of spots in ada-lang.c). I've always found it awkward when I needed to edit one of these spots: do I keep the original wrong indentation, or do I fix it? What if the lines around it are also wrong, do I fix them too? I probably don't want to fix them in the same patch, to avoid adding noise to my patch. So I propose to fix as much as possible once and for all (hopefully). One typical counter argument for this is that it makes code archeology more difficult, because git-blame will show this commit as the last change for these lines. My counter counter argument is: when git-blaming, you often need to do "blame the file at the parent commit" anyway, to go past some other refactor that touched the line you are interested in, but is not the change you are looking for. So you already need a somewhat efficient way to do this. Using some interactive tool, rather than plain git-blame, makes this trivial. For example, I use "tig blame <file>", where going back past the commit that changed the currently selected line is one keystroke. It looks like Magit in Emacs does it too (though I've never used it). Web viewers of Github and Gitlab do it too. My point is that it won't really make archeology more difficult. The other typical counter argument is that it will cause conflicts with existing patches. That's true... but it's a one time cost, and those are not conflicts that are difficult to resolve. I have also tried "git rebase --ignore-whitespace", it seems to work well. Although that will re-introduce the faulty indentation, so one needs to take care of fixing the indentation in the patch after that (which is easy). gdb/ChangeLog: * aarch64-linux-tdep.c: Fix indentation. * aarch64-ravenscar-thread.c: Fix indentation. * aarch64-tdep.c: Fix indentation. * aarch64-tdep.h: Fix indentation. * ada-lang.c: Fix indentation. * ada-lang.h: Fix indentation. * ada-tasks.c: Fix indentation. * ada-typeprint.c: Fix indentation. * ada-valprint.c: Fix indentation. * ada-varobj.c: Fix indentation. * addrmap.c: Fix indentation. * addrmap.h: Fix indentation. * agent.c: Fix indentation. * aix-thread.c: Fix indentation. * alpha-bsd-nat.c: Fix indentation. * alpha-linux-tdep.c: Fix indentation. * alpha-mdebug-tdep.c: Fix indentation. * alpha-nbsd-tdep.c: Fix indentation. * alpha-obsd-tdep.c: Fix indentation. * alpha-tdep.c: Fix indentation. * amd64-bsd-nat.c: Fix indentation. * amd64-darwin-tdep.c: Fix indentation. * amd64-linux-nat.c: Fix indentation. * amd64-linux-tdep.c: Fix indentation. * amd64-nat.c: Fix indentation. * amd64-obsd-tdep.c: Fix indentation. * amd64-tdep.c: Fix indentation. * amd64-windows-tdep.c: Fix indentation. * annotate.c: Fix indentation. * arc-tdep.c: Fix indentation. * arch-utils.c: Fix indentation. * arch/arm-get-next-pcs.c: Fix indentation. * arch/arm.c: Fix indentation. * arm-linux-nat.c: Fix indentation. * arm-linux-tdep.c: Fix indentation. * arm-nbsd-tdep.c: Fix indentation. * arm-pikeos-tdep.c: Fix indentation. * arm-tdep.c: Fix indentation. * arm-tdep.h: Fix indentation. * arm-wince-tdep.c: Fix indentation. * auto-load.c: Fix indentation. * auxv.c: Fix indentation. * avr-tdep.c: Fix indentation. * ax-gdb.c: Fix indentation. * ax-general.c: Fix indentation. * bfin-linux-tdep.c: Fix indentation. * block.c: Fix indentation. * block.h: Fix indentation. * blockframe.c: Fix indentation. * bpf-tdep.c: Fix indentation. * break-catch-sig.c: Fix indentation. * break-catch-syscall.c: Fix indentation. * break-catch-throw.c: Fix indentation. * breakpoint.c: Fix indentation. * breakpoint.h: Fix indentation. * bsd-uthread.c: Fix indentation. * btrace.c: Fix indentation. * build-id.c: Fix indentation. * buildsym-legacy.h: Fix indentation. * buildsym.c: Fix indentation. * c-typeprint.c: Fix indentation. * c-valprint.c: Fix indentation. * c-varobj.c: Fix indentation. * charset.c: Fix indentation. * cli/cli-cmds.c: Fix indentation. * cli/cli-decode.c: Fix indentation. * cli/cli-decode.h: Fix indentation. * cli/cli-script.c: Fix indentation. * cli/cli-setshow.c: Fix indentation. * coff-pe-read.c: Fix indentation. * coffread.c: Fix indentation. * compile/compile-cplus-types.c: Fix indentation. * compile/compile-object-load.c: Fix indentation. * compile/compile-object-run.c: Fix indentation. * completer.c: Fix indentation. * corefile.c: Fix indentation. * corelow.c: Fix indentation. * cp-abi.h: Fix indentation. * cp-namespace.c: Fix indentation. * cp-support.c: Fix indentation. * cp-valprint.c: Fix indentation. * cris-linux-tdep.c: Fix indentation. * cris-tdep.c: Fix indentation. * darwin-nat-info.c: Fix indentation. * darwin-nat.c: Fix indentation. * darwin-nat.h: Fix indentation. * dbxread.c: Fix indentation. * dcache.c: Fix indentation. * disasm.c: Fix indentation. * dtrace-probe.c: Fix indentation. * dwarf2/abbrev.c: Fix indentation. * dwarf2/attribute.c: Fix indentation. * dwarf2/expr.c: Fix indentation. * dwarf2/frame.c: Fix indentation. * dwarf2/index-cache.c: Fix indentation. * dwarf2/index-write.c: Fix indentation. * dwarf2/line-header.c: Fix indentation. * dwarf2/loc.c: Fix indentation. * dwarf2/macro.c: Fix indentation. * dwarf2/read.c: Fix indentation. * dwarf2/read.h: Fix indentation. * elfread.c: Fix indentation. * eval.c: Fix indentation. * event-top.c: Fix indentation. * exec.c: Fix indentation. * exec.h: Fix indentation. * expprint.c: Fix indentation. * f-lang.c: Fix indentation. * f-typeprint.c: Fix indentation. * f-valprint.c: Fix indentation. * fbsd-nat.c: Fix indentation. * fbsd-tdep.c: Fix indentation. * findvar.c: Fix indentation. * fork-child.c: Fix indentation. * frame-unwind.c: Fix indentation. * frame-unwind.h: Fix indentation. * frame.c: Fix indentation. * frv-linux-tdep.c: Fix indentation. * frv-tdep.c: Fix indentation. * frv-tdep.h: Fix indentation. * ft32-tdep.c: Fix indentation. * gcore.c: Fix indentation. * gdb_bfd.c: Fix indentation. * gdbarch.sh: Fix indentation. * gdbarch.c: Re-generate * gdbarch.h: Re-generate. * gdbcore.h: Fix indentation. * gdbthread.h: Fix indentation. * gdbtypes.c: Fix indentation. * gdbtypes.h: Fix indentation. * glibc-tdep.c: Fix indentation. * gnu-nat.c: Fix indentation. * gnu-nat.h: Fix indentation. * gnu-v2-abi.c: Fix indentation. * gnu-v3-abi.c: Fix indentation. * go32-nat.c: Fix indentation. * guile/guile-internal.h: Fix indentation. * guile/scm-cmd.c: Fix indentation. * guile/scm-frame.c: Fix indentation. * guile/scm-iterator.c: Fix indentation. * guile/scm-math.c: Fix indentation. * guile/scm-ports.c: Fix indentation. * guile/scm-pretty-print.c: Fix indentation. * guile/scm-value.c: Fix indentation. * h8300-tdep.c: Fix indentation. * hppa-linux-nat.c: Fix indentation. * hppa-linux-tdep.c: Fix indentation. * hppa-nbsd-nat.c: Fix indentation. * hppa-nbsd-tdep.c: Fix indentation. * hppa-obsd-nat.c: Fix indentation. * hppa-tdep.c: Fix indentation. * hppa-tdep.h: Fix indentation. * i386-bsd-nat.c: Fix indentation. * i386-darwin-nat.c: Fix indentation. * i386-darwin-tdep.c: Fix indentation. * i386-dicos-tdep.c: Fix indentation. * i386-gnu-nat.c: Fix indentation. * i386-linux-nat.c: Fix indentation. * i386-linux-tdep.c: Fix indentation. * i386-nto-tdep.c: Fix indentation. * i386-obsd-tdep.c: Fix indentation. * i386-sol2-nat.c: Fix indentation. * i386-tdep.c: Fix indentation. * i386-tdep.h: Fix indentation. * i386-windows-tdep.c: Fix indentation. * i387-tdep.c: Fix indentation. * i387-tdep.h: Fix indentation. * ia64-libunwind-tdep.c: Fix indentation. * ia64-libunwind-tdep.h: Fix indentation. * ia64-linux-nat.c: Fix indentation. * ia64-linux-tdep.c: Fix indentation. * ia64-tdep.c: Fix indentation. * ia64-tdep.h: Fix indentation. * ia64-vms-tdep.c: Fix indentation. * infcall.c: Fix indentation. * infcmd.c: Fix indentation. * inferior.c: Fix indentation. * infrun.c: Fix indentation. * iq2000-tdep.c: Fix indentation. * language.c: Fix indentation. * linespec.c: Fix indentation. * linux-fork.c: Fix indentation. * linux-nat.c: Fix indentation. * linux-tdep.c: Fix indentation. * linux-thread-db.c: Fix indentation. * lm32-tdep.c: Fix indentation. * m2-lang.c: Fix indentation. * m2-typeprint.c: Fix indentation. * m2-valprint.c: Fix indentation. * m32c-tdep.c: Fix indentation. * m32r-linux-tdep.c: Fix indentation. * m32r-tdep.c: Fix indentation. * m68hc11-tdep.c: Fix indentation. * m68k-bsd-nat.c: Fix indentation. * m68k-linux-nat.c: Fix indentation. * m68k-linux-tdep.c: Fix indentation. * m68k-tdep.c: Fix indentation. * machoread.c: Fix indentation. * macrocmd.c: Fix indentation. * macroexp.c: Fix indentation. * macroscope.c: Fix indentation. * macrotab.c: Fix indentation. * macrotab.h: Fix indentation. * main.c: Fix indentation. * mdebugread.c: Fix indentation. * mep-tdep.c: Fix indentation. * mi/mi-cmd-catch.c: Fix indentation. * mi/mi-cmd-disas.c: Fix indentation. * mi/mi-cmd-env.c: Fix indentation. * mi/mi-cmd-stack.c: Fix indentation. * mi/mi-cmd-var.c: Fix indentation. * mi/mi-cmds.c: Fix indentation. * mi/mi-main.c: Fix indentation. * mi/mi-parse.c: Fix indentation. * microblaze-tdep.c: Fix indentation. * minidebug.c: Fix indentation. * minsyms.c: Fix indentation. * mips-linux-nat.c: Fix indentation. * mips-linux-tdep.c: Fix indentation. * mips-nbsd-tdep.c: Fix indentation. * mips-tdep.c: Fix indentation. * mn10300-linux-tdep.c: Fix indentation. * mn10300-tdep.c: Fix indentation. * moxie-tdep.c: Fix indentation. * msp430-tdep.c: Fix indentation. * namespace.h: Fix indentation. * nat/fork-inferior.c: Fix indentation. * nat/gdb_ptrace.h: Fix indentation. * nat/linux-namespaces.c: Fix indentation. * nat/linux-osdata.c: Fix indentation. * nat/netbsd-nat.c: Fix indentation. * nat/x86-dregs.c: Fix indentation. * nbsd-nat.c: Fix indentation. * nbsd-tdep.c: Fix indentation. * nios2-linux-tdep.c: Fix indentation. * nios2-tdep.c: Fix indentation. * nto-procfs.c: Fix indentation. * nto-tdep.c: Fix indentation. * objfiles.c: Fix indentation. * objfiles.h: Fix indentation. * opencl-lang.c: Fix indentation. * or1k-tdep.c: Fix indentation. * osabi.c: Fix indentation. * osabi.h: Fix indentation. * osdata.c: Fix indentation. * p-lang.c: Fix indentation. * p-typeprint.c: Fix indentation. * p-valprint.c: Fix indentation. * parse.c: Fix indentation. * ppc-linux-nat.c: Fix indentation. * ppc-linux-tdep.c: Fix indentation. * ppc-nbsd-nat.c: Fix indentation. * ppc-nbsd-tdep.c: Fix indentation. * ppc-obsd-nat.c: Fix indentation. * ppc-ravenscar-thread.c: Fix indentation. * ppc-sysv-tdep.c: Fix indentation. * ppc64-tdep.c: Fix indentation. * printcmd.c: Fix indentation. * proc-api.c: Fix indentation. * producer.c: Fix indentation. * producer.h: Fix indentation. * prologue-value.c: Fix indentation. * prologue-value.h: Fix indentation. * psymtab.c: Fix indentation. * python/py-arch.c: Fix indentation. * python/py-bpevent.c: Fix indentation. * python/py-event.c: Fix indentation. * python/py-event.h: Fix indentation. * python/py-finishbreakpoint.c: Fix indentation. * python/py-frame.c: Fix indentation. * python/py-framefilter.c: Fix indentation. * python/py-inferior.c: Fix indentation. * python/py-infthread.c: Fix indentation. * python/py-objfile.c: Fix indentation. * python/py-prettyprint.c: Fix indentation. * python/py-registers.c: Fix indentation. * python/py-signalevent.c: Fix indentation. * python/py-stopevent.c: Fix indentation. * python/py-stopevent.h: Fix indentation. * python/py-threadevent.c: Fix indentation. * python/py-tui.c: Fix indentation. * python/py-unwind.c: Fix indentation. * python/py-value.c: Fix indentation. * python/py-xmethods.c: Fix indentation. * python/python-internal.h: Fix indentation. * python/python.c: Fix indentation. * ravenscar-thread.c: Fix indentation. * record-btrace.c: Fix indentation. * record-full.c: Fix indentation. * record.c: Fix indentation. * reggroups.c: Fix indentation. * regset.h: Fix indentation. * remote-fileio.c: Fix indentation. * remote.c: Fix indentation. * reverse.c: Fix indentation. * riscv-linux-tdep.c: Fix indentation. * riscv-ravenscar-thread.c: Fix indentation. * riscv-tdep.c: Fix indentation. * rl78-tdep.c: Fix indentation. * rs6000-aix-tdep.c: Fix indentation. * rs6000-lynx178-tdep.c: Fix indentation. * rs6000-nat.c: Fix indentation. * rs6000-tdep.c: Fix indentation. * rust-lang.c: Fix indentation. * rx-tdep.c: Fix indentation. * s12z-tdep.c: Fix indentation. * s390-linux-tdep.c: Fix indentation. * score-tdep.c: Fix indentation. * ser-base.c: Fix indentation. * ser-mingw.c: Fix indentation. * ser-uds.c: Fix indentation. * ser-unix.c: Fix indentation. * serial.c: Fix indentation. * sh-linux-tdep.c: Fix indentation. * sh-nbsd-tdep.c: Fix indentation. * sh-tdep.c: Fix indentation. * skip.c: Fix indentation. * sol-thread.c: Fix indentation. * solib-aix.c: Fix indentation. * solib-darwin.c: Fix indentation. * solib-frv.c: Fix indentation. * solib-svr4.c: Fix indentation. * solib.c: Fix indentation. * source.c: Fix indentation. * sparc-linux-tdep.c: Fix indentation. * sparc-nbsd-tdep.c: Fix indentation. * sparc-obsd-tdep.c: Fix indentation. * sparc-ravenscar-thread.c: Fix indentation. * sparc-tdep.c: Fix indentation. * sparc64-linux-tdep.c: Fix indentation. * sparc64-nbsd-tdep.c: Fix indentation. * sparc64-obsd-tdep.c: Fix indentation. * sparc64-tdep.c: Fix indentation. * stabsread.c: Fix indentation. * stack.c: Fix indentation. * stap-probe.c: Fix indentation. * stubs/ia64vms-stub.c: Fix indentation. * stubs/m32r-stub.c: Fix indentation. * stubs/m68k-stub.c: Fix indentation. * stubs/sh-stub.c: Fix indentation. * stubs/sparc-stub.c: Fix indentation. * symfile-mem.c: Fix indentation. * symfile.c: Fix indentation. * symfile.h: Fix indentation. * symmisc.c: Fix indentation. * symtab.c: Fix indentation. * symtab.h: Fix indentation. * target-float.c: Fix indentation. * target.c: Fix indentation. * target.h: Fix indentation. * tic6x-tdep.c: Fix indentation. * tilegx-linux-tdep.c: Fix indentation. * tilegx-tdep.c: Fix indentation. * top.c: Fix indentation. * tracefile-tfile.c: Fix indentation. * tracepoint.c: Fix indentation. * tui/tui-disasm.c: Fix indentation. * tui/tui-io.c: Fix indentation. * tui/tui-regs.c: Fix indentation. * tui/tui-stack.c: Fix indentation. * tui/tui-win.c: Fix indentation. * tui/tui-winsource.c: Fix indentation. * tui/tui.c: Fix indentation. * typeprint.c: Fix indentation. * ui-out.h: Fix indentation. * unittests/copy_bitwise-selftests.c: Fix indentation. * unittests/memory-map-selftests.c: Fix indentation. * utils.c: Fix indentation. * v850-tdep.c: Fix indentation. * valarith.c: Fix indentation. * valops.c: Fix indentation. * valprint.c: Fix indentation. * valprint.h: Fix indentation. * value.c: Fix indentation. * value.h: Fix indentation. * varobj.c: Fix indentation. * vax-tdep.c: Fix indentation. * windows-nat.c: Fix indentation. * windows-tdep.c: Fix indentation. * xcoffread.c: Fix indentation. * xml-syscall.c: Fix indentation. * xml-tdesc.c: Fix indentation. * xstormy16-tdep.c: Fix indentation. * xtensa-config.c: Fix indentation. * xtensa-linux-nat.c: Fix indentation. * xtensa-linux-tdep.c: Fix indentation. * xtensa-tdep.c: Fix indentation. gdbserver/ChangeLog: * ax.cc: Fix indentation. * dll.cc: Fix indentation. * inferiors.h: Fix indentation. * linux-low.cc: Fix indentation. * linux-nios2-low.cc: Fix indentation. * linux-ppc-ipa.cc: Fix indentation. * linux-ppc-low.cc: Fix indentation. * linux-x86-low.cc: Fix indentation. * linux-xtensa-low.cc: Fix indentation. * regcache.cc: Fix indentation. * server.cc: Fix indentation. * tracepoint.cc: Fix indentation. gdbsupport/ChangeLog: * common-exceptions.h: Fix indentation. * event-loop.cc: Fix indentation. * fileio.cc: Fix indentation. * filestuff.cc: Fix indentation. * gdb-dlfcn.cc: Fix indentation. * gdb_string_view.h: Fix indentation. * job-control.cc: Fix indentation. * signals.cc: Fix indentation. Change-Id: I4bad7ae6be0fbe14168b8ebafb98ffe14964a695
2020-10-22gdb: make target_ops::make_corefile_notes return a unique ptrSimon Marchi1-1/+1
Since we converted gdbarch_make_corefile_notes to returning a gdb::unique_xmalloc_ptr, I figured it would make sense to converted target_ops::make_corefile_notes as well. The only implementation of that is in procfs.c, and it should ideally be re-written as a gdbarch method (see comment in write_gcore_file_1), but in the mean time I guess it doesn't hurt to throw some unique pointer at it. I tested that it builds on Solaris 11 (gcc compile farm machine gcc211), but I am not able to test it, because I can't get GDB to start a process (I'll look at that separately). gdb/ChangeLog: * target.h (struct target_ops) <make_corefile_notes>: Change return type to unique pointer. * target.c (dummy_make_corefile_notes): Likewise. * exec.c (struct exec_target) <make_corefile_notes>: Likewise. (exec_target::make_corefile_notes): Likewise. * procfs.c (class procfs_target) <make_corefile_notes>: Likewise. (procfs_do_thread_registers): Adjust to unique pointer. (struct procfs_corefile_thread_data): Add constructor. <note_data>: Change type to unique pointer. (procfs_corefile_thread_callback): Adjust to unique pointer. (procfs_target::make_corefile_notes): Change return type to unique pointer. * target-delegates.c: Re-generate. * gcore.c (write_gcore_file_1): Adjust. * target-debug.h (target_debug_print_gdb_unique_xmalloc_ptr_char): New. Change-Id: I768fb17ac0f7adc67d2fe95e952c784fe0ac37ab
2020-10-12Change target_section_table to std::vector aliasTom Tromey1-3/+2
Because target_section_table only holds a vector, and because it is used in an "open" way, this patch makes it just be an alias for the std::vector specialization. This makes the code less wordy. If we do ever want to add more specialized behavior to this type, it's simple enough to convert it back to a struct with the few needed methods implied by this change. gdb/ChangeLog 2020-10-12 Tom Tromey <tom@tromey.com> * target.h (struct target_ops) <get_section_table>: Update. (target_get_section_table): Update. * target.c (target_get_section_table, target_section_by_addr) (memory_xfer_partial_1): Update. * target-section.h (target_section_table): Now an alias. * target-delegates.c: Rebuild. * target-debug.h (target_debug_print_target_section_table_p): Rename from target_debug_print_struct_target_section_table_p. * symfile.c (build_section_addr_info_from_section_table): Update. * solib.c (solib_map_sections, solib_contains_address_p): Update. * solib-svr4.c (scan_dyntag): Update. * solib-dsbt.c (scan_dyntag): Update. * remote.c (remote_target::remote_xfer_live_readonly_partial): Update. * record-full.c (record_full_core_target::xfer_partial): Update. * progspace.h (struct program_space) <target_sections>: Update. * exec.h (print_section_info): Update. * exec.c (exec_target::close, build_section_table) (add_target_sections, add_target_sections_of_objfile) (remove_target_sections, exec_on_vfork) (section_table_available_memory) (section_table_xfer_memory_partial) (exec_target::get_section_table, exec_target::xfer_partial) (print_section_info, set_section_command) (exec_set_section_address, exec_target::has_memory): Update. * corelow.c (core_target::build_file_mappings) (core_target::xfer_partial, core_target::info_proc_mappings) (core_target::info_proc_mappings): Update. * bfd-target.c (class target_bfd): Update
2020-10-12Introduce target-section.hTom Tromey1-27/+1
This introduces a new target-section.h file. This makes some of the later patches in this series a bit cleaner, because new includes of target.h won't be required. Also I think it's better to have small header files for each separate data structure. gdb/ChangeLog 2020-10-12 Tom Tromey <tom@tromey.com> * target.h (struct target_section, struct target_section_table): Move to target-section.h. * target-section.h: New file.
2020-10-07Move simple_search_memory to gdbsupport/search.ccTom Tromey1-8/+0
This moves the simple_search_memory function to a new file, gdbsupport/search.cc. The API is slightly changed to make it more general. This generality is useful for wiring it to gdbserver, and also for unit testing. gdb/ChangeLog 2020-10-07 Tom Tromey <tromey@adacore.com> * target.h (simple_search_memory): Don't declare. * target.c (simple_search_memory): Move to gdbsupport. (default_search_memory): Update. * remote.c (remote_target::search_memory): Update. gdbsupport/ChangeLog 2020-10-07 Tom Tromey <tromey@adacore.com> * Makefile.in: Rebuild. * Makefile.am (libgdbsupport_a_SOURCES): Add search.cc. * search.h: New file. * search.cc: New file.
2020-09-28Turn target_have_steppable_watchpoint into functionTom Tromey1-2/+5
This changes the object-like macro target_have_steppable_watchpoint into an inline function. gdb/ChangeLog 2020-09-28 Tom Tromey <tom@tromey.com> * infrun.c (displaced_step_fixup, thread_still_needs_step_over) (handle_signal_stop): Update. * procfs.c (procfs_target::insert_watchpoint): Update. * target.h (target_have_steppable_watchpoint): Now a function.
2020-09-28Turn target_can_lock_scheduler into a functionTom Tromey1-2/+6
This changes the object-like macro target_can_lock_scheduler into an inline function. gdb/ChangeLog 2020-09-28 Tom Tromey <tom@tromey.com> * infrun.c (set_schedlock_func): Update. * target.h (target_can_lock_scheduler): Now a function.
2020-09-28Remove target_has_execution macroTom Tromey1-9/+3
This removes the object-like macro target_has_execution, replacing it with a function call. target_has_execution_current is also now handled by this function. gdb/ChangeLog 2020-09-28 Tom Tromey <tom@tromey.com> * inferior.h (class inferior) <has_execution>: Update. * windows-tdep.c (windows_solib_create_inferior_hook): Update. * valops.c (find_function_in_inferior) (value_allocate_space_in_inferior): Update. * top.c (kill_or_detach): Update. * target.c (target_preopen, set_target_permissions): Update. (target_has_execution_current): Remove. * sparc64-tdep.c (adi_examine_command, adi_assign_command): Update. * solib.c (update_solib_list, reload_shared_libraries): Update. * solib-svr4.c (svr4_solib_create_inferior_hook): Update. * solib-dsbt.c (enable_break): Update. * score-tdep.c (score7_fetch_inst): Update. * rs6000-nat.c (rs6000_nat_target::xfer_shared_libraries): Update. * remote.c (remote_target::start_remote) (remote_target::remote_check_symbols, remote_target::open_1) (remote_target::remote_detach_1, remote_target::verify_memory) (remote_target::xfer_partial, remote_target::read_description) (remote_target::get_min_fast_tracepoint_insn_len): Update. * record-full.c (record_full_open_1): Update. * record-btrace.c (record_btrace_target_open): Update. * objc-lang.c (lookup_objc_class, lookup_child_selector) (value_nsstring): Update. * linux-thread-db.c (add_thread_db_info) (thread_db_find_new_threads_silently, check_thread_db_callback) (try_thread_db_load_1, record_thread): Update. * linux-tdep.c (linux_info_proc, linux_vsyscall_range_raw): Update. * linux-fork.c (checkpoint_command): Update. * infrun.c (set_non_stop, set_observer_mode) (check_multi_target_resumption, for_each_just_stopped_thread) (maybe_remove_breakpoints, normal_stop) (class infcall_suspend_state): Update. * infcmd.c (ERROR_NO_INFERIOR, kill_if_already_running) (info_program_command, attach_command): Update. * infcall.c (call_function_by_hand_dummy): Update. * inf-loop.c (inferior_event_handler): Update. * gcore.c (gcore_command, derive_heap_segment): Update. * exec.c (exec_file_command): Update. * eval.c (evaluate_subexp): Update. * compile/compile.c (compile_to_object): Update. * cli/cli-dump.c (restore_command): Update. * breakpoint.c (update_watchpoint) (update_inserted_breakpoint_locations) (insert_breakpoint_locations, get_bpstat_thread): Update. * target.h (target_has_execution): Remove macro. (target_has_execution_current): Don't declare. (target_has_execution): Rename from target_has_execution_1. Add argument default.
2020-09-28Turn target_can_execute_reverse into functionTom Tromey1-2/+5
This changes target_can_execute_reverse from an object-like macro to an inline function. gdb/ChangeLog 2020-09-28 Tom Tromey <tom@tromey.com> * mi/mi-main.c (exec_reverse_continue) (mi_cmd_list_target_features): Update. * infrun.c (set_exec_direction_func): Update. * target.c (default_execution_direction): Update. * reverse.c (exec_reverse_once): Update. * target.h (target_can_execute_reverse): Now a function.
2020-09-28Remove target_has_registers macroTom Tromey1-2/+1
This removes the target_has_registers object-like macro, replacing it with the underlying function. gdb/ChangeLog 2020-09-28 Tom Tromey <tom@tromey.com> * tui/tui-regs.c (tui_get_register) (tui_data_window::show_registers): Update. * thread.c (scoped_restore_current_thread::restore) (scoped_restore_current_thread::scoped_restore_current_thread): Update. * regcache-dump.c (regcache_print): Update. * python/py-finishbreakpoint.c (bpfinishpy_detect_out_scope_cb): Update. * mi/mi-main.c (mi_cmd_data_write_register_values): Update. * mep-tdep.c (current_me_module, current_options): Update. * linux-thread-db.c (thread_db_load): Update. * infcmd.c (registers_info, info_vector_command) (info_float_command): Update. * ia64-tdep.c (ia64_frame_prev_register) (ia64_sigtramp_frame_prev_register): Update. * ia64-libunwind-tdep.c (libunwind_frame_prev_register): Update. * gcore.c (derive_stack_segment): Update. * frame.c (get_current_frame, has_stack_frames): Update. * findvar.c (language_defn::read_var_value): Update. * arm-tdep.c (arm_pc_is_thumb): Update. * target.c (target_has_registers): Rename from target_has_registers_1. * target.h (target_has_registers): Remove macro. (target_has_registers): Rename from target_has_registers_1.
2020-09-28Remove target_has_stack macroTom Tromey1-2/+1
This removes the target_has_stack object-like macro, replacing it with the underlying function. gdb/ChangeLog 2020-09-28 Tom Tromey <tom@tromey.com> * windows-tdep.c (tlb_make_value): Update. * tui/tui-regs.c (tui_data_window::show_registers): Update. * thread.c (scoped_restore_current_thread::restore) (scoped_restore_current_thread::scoped_restore_current_thread) (thread_command): Update. * stack.c (backtrace_command_1, frame_apply_level_command) (frame_apply_all_command, frame_apply_command): Update. * infrun.c (siginfo_make_value, restore_infcall_control_state): Update. * gcore.c (derive_stack_segment): Update. * frame.c (get_current_frame, has_stack_frames): Update. * auxv.c (info_auxv_command): Update. * ada-tasks.c (ada_build_task_list): Update. * target.c (target_has_stack): Rename from target_has_stack_1. * target.h (target_has_stack): Remove macro. (target_has_stack): Rename from target_has_stack_1.
2020-09-28Remove target_has_memory macroTom Tromey1-2/+1
This removes the target_has_memory object-like macro, replacing it with the underlying function. gdb/ChangeLog 2020-09-28 Tom Tromey <tom@tromey.com> * target.c (target_has_memory): Rename from target_has_memory_1. * tui/tui-regs.c (tui_data_window::show_registers): Update. * thread.c (scoped_restore_current_thread::restore) (scoped_restore_current_thread::scoped_restore_current_thread): Update. * frame.c (get_current_frame, has_stack_frames): Update. * target.h (target_has_memory): Remove macro. (target_has_memory): Rename from target_has_memory_1.
2020-09-28Remove target_has_all_memoryTom Tromey1-7/+0
target_has_all_memory isn't used anywhere, so this patch removes it. gdb/ChangeLog 2020-09-28 Tom Tromey <tom@tromey.com> * target.c (target_has_all_memory_1): Remove. * target.h (target_has_all_memory): Remove define. (target_has_all_memory_1): Don't declare.
2020-09-18Make target_wait options use enum flagsTom Tromey1-3/+3
This changes TARGET_WNOHANG to be a member of an enum, rather than a define, and also adds a DEF_ENUM_FLAGS_TYPE for this type. Then, it changes target_wait and the various target wait methods to use this type rather than "int". This didn't catch any bugs, but it seems like a decent cleanup nevertheless. I did not change deprecated_target_wait_hook, since that's only used out-of-tree (by Insight), and there didn't seem to be a need. I can't build some of these targets, so I modified them on a best-effort basis. I don't think this patch should go in before the release branch is made. gdb/ChangeLog 2020-09-18 Tom Tromey <tromey@adacore.com> * windows-nat.c (struct windows_nat_target) <wait>: Update. (windows_nat_target::wait): Update. * target/wait.h (enum target_wait_flag): New. Use DEF_ENUM_FLAGS_TYPE. * target/target.h (target_wait): Change type of options. * target.h (target_options_to_string, default_target_wait): Update. (struct target_ops) <wait>: Change type of options. * target.c (target_wait, default_target_wait, do_option): Change type of "options". (target_options_to_string): Likewise. * target-delegates.c: Rebuild. * target-debug.h (target_debug_print_target_wait_flags): Rename from target_debug_print_options. * sol-thread.c (class sol_thread_target) <wait>: Update. (sol_thread_target::wait): Update. * rs6000-nat.c (class rs6000_nat_target) <wait>: Update. (rs6000_nat_target::wait): Update. * remote.c (class remote_target) <wait, wait_ns, wait_as>: Update. (remote_target::wait_ns, remote_target::wait_as): Change type of "options". (remote_target::wait): Update. * remote-sim.c (struct gdbsim_target) <wait>: Update. (gdbsim_target::wait): Update. * record-full.c (class record_full_base_target) <wait>: Update. (record_full_wait_1): Change type of "options". (record_full_base_target::wait): Update. * record-btrace.c (class record_btrace_target) <wait>: Update. (record_btrace_target::wait): Update. * ravenscar-thread.c (struct ravenscar_thread_target) <wait>: Update. (ravenscar_thread_target::wait): Update. * procfs.c (class procfs_target) <wait>: Update. (procfs_target::wait): Update. * obsd-nat.h (class obsd_nat_target) <wait>: Update. * obsd-nat.c (obsd_nat_target::wait): Update. * nto-procfs.c (struct nto_procfs_target) <wait>: Update. (nto_procfs_target::wait): Update. * nbsd-nat.h (struct nbsd_nat_target) <wait>: Update. * nbsd-nat.c (nbsd_wait): Change type of "options". (nbsd_nat_target::wait): Update. * linux-thread-db.c (class thread_db_target) <wait>: Update. (thread_db_target::wait): Update. * linux-nat.h (class linux_nat_target) <wait>: Update. * linux-nat.c (linux_nat_target::wait): Update. (linux_nat_wait_1): Update. * infrun.c (do_target_wait_1, do_target_wait): Change type of "options". * inf-ptrace.h (struct inf_ptrace_target) <wait>: Update. * inf-ptrace.c (inf_ptrace_target::wait): Update. * go32-nat.c (struct go32_nat_target) <wait>: Update. (go32_nat_target::wait): Update. * gnu-nat.h (struct gnu_nat_target) <wait>: Update. * gnu-nat.c (gnu_nat_target::wait): Update. * fbsd-nat.h (class fbsd_nat_target) <wait>: Update. * fbsd-nat.c (fbsd_nat_target::wait): Update. * darwin-nat.h (class darwin_nat_target) <wait>: Update. * darwin-nat.c (darwin_nat_target::wait): Update. * bsd-uthread.c (struct bsd_uthread_target) <wait>: Update. (bsd_uthread_target::wait): Update. * aix-thread.c (class aix_thread_target) <wait>: Update. (aix_thread_target::wait): Update. gdbserver/ChangeLog 2020-09-18 Tom Tromey <tromey@adacore.com> * netbsd-low.h (class netbsd_process_target) <wait>: Update. * netbsd-low.cc (netbsd_waitpid, netbsd_wait) (netbsd_process_target::wait): Change type of target_options. * win32-low.h (class win32_process_target) <wait>: Update. * win32-low.cc (win32_process_target::wait): Update. * target.h (class process_stratum_target) <wait>: Update. (mywait): Update. * target.cc (mywait, target_wait): Change type of "options". * linux-low.h (class linux_process_target) <wait, wait_1>: Update. * linux-low.cc (linux_process_target::wait) (linux_process_target::wait_1): Update.
2020-08-14gdb: Implement native dumpcore functionKamil Rytarowski1-0/+18
Add new API for systems with native kernel support for dumping a process on demand. Wire it into the gdb's gcore functionality. gdb/ChangeLog: * target.h (supports_dumpcore, dumpcore): New function declarations. * target.c (supports_dumpcore, dumpcore): New functions. * target-delegates.c: Rebuild. * gcore.c (gcore_command): Use target_supports_dumpcore () and target_dumpcore ().
2020-06-15Change target_read_string APITom Tromey1-2/+7
This simplifies the target_read_string API a bit. Note that some code was using safe_strerror on the error codes returned by target_read_string. It seems to me that this is incorrect (if it was ever correct, it must have been quite a long time ago). gdb/ChangeLog 2020-06-15 Tom Tromey <tromey@adacore.com> * windows-nat.c (windows_nat::handle_output_debug_string): Update. (windows_nat::handle_ms_vc_exception): Update. * target.h (target_read_string): Change API. * target.c (target_read_string): Change API. * solib-svr4.c (open_symbol_file_object, svr4_read_so_list): Update. * solib-frv.c (frv_current_sos): Update. * solib-dsbt.c (dsbt_current_sos): Update. * solib-darwin.c (darwin_current_sos): Update. * linux-thread-db.c (inferior_has_bug): Update. * expprint.c (print_subexp_standard): Update. * ada-lang.c (ada_main_name, ada_tag_name_from_tsd) (ada_exception_message_1): Update.
2020-05-19Eliminate target_fileio_open_warn_if_slowPedro Alves1-13/+7
This basically makes target_fileio_open_1 extern, renamed to target_fileio_open, and eliminates the current target_fileio_open_warn_if_slow and target_fileio_open. A following parameter will want to change gdb_bfd_iovec_fileio_open, the only caller of target_fileio_open_warn_if_slow, to pass down "warn_if_slow" true/false from the caller, instead of hardcoding "warn_if_slow" true. gdb/ChangeLog: 2020-05-19 Pedro Alves <palves@redhat.com> * gdb_bfd.c (gdb_bfd_iovec_fileio_open): Adjust. * target.c (target_fileio_open_1): Rename to target_fileio_open and make extern. Use bool. (target_fileio_open, target_fileio_open_warn_if_slow): Delete. (target_fileio_read_alloc_1): Adjust. * target.h (target_fileio_open): Add 'warn_if_slow' parameter. (target_fileio_open_warn_if_slow): Delete declaration.
2020-04-01gdb: define convenience function 'exists_non_stop_target'Tankut Baris Aktemur1-0/+3
Define a predicate function that returns true if there exists an inferior with a non-stop target. gdb/ChangeLog: 2020-04-01 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com> * target.h (exists_non_stop_target): New function declaration. * target.c (exists_non_stop_target): New function.
2020-03-24gdb: bool-ify follow_forkSimon Marchi1-3/+3
Change parameters and return value of the various follow_fork functions/methods from int to bool. gdb/ChangeLog: * fbsd-nat.c (fbsd_nat_target::follow_fork): Change bool to int. * fbsd-nat.h (class fbsd_nat_target) <follow_fork>: Likewise. * inf-ptrace.c (inf_ptrace_target::follow_fork): Likewise. * inf-ptrace.h (struct inf_ptrace_target) <follow_fork>: Likewise. * infrun.c (follow_fork): Likewise. (follow_fork_inferior): Likewise. * linux-nat.c (linux_nat_target::follow_fork): Likewise. * linux-nat.h (class linux_nat_target): Likewise. * remote.c (class remote_target) <follow_fork>: Likewise. (remote_target::follow_fork): Likewise. * target-delegates.c: Re-generate. * target.c (default_follow_fork): Likewise. (target_follow_fork): Likewise. * target.h (struct target_ops) <follow_fork>: Likewise. (target_follow_fork): Likewise.
2020-01-10Multi-target supportPedro Alves1-3/+31
This commit adds multi-target support to GDB. What this means is that with this commit, GDB can now be connected to different targets at the same time. E.g., you can debug a live native process and a core dump at the same time, connect to multiple gdbservers, etc. Actually, the word "target" is overloaded in gdb. We already have a target stack, with pushes several target_ops instances on top of one another. We also have "info target" already, which means something completely different to what this patch does. So from here on, I'll be using the "target connections" term, to mean an open process_stratum target, pushed on a target stack. This patch makes gdb have multiple target stacks, and multiple process_stratum targets open simultaneously. The user-visible changes / commands will also use this terminology, but of course it's all open to debate. User-interface-wise, not that much changes. The main difference is that each inferior may have its own target connection. A target connection (e.g., a target extended-remote connection) may support debugging multiple processes, just as before. Say you're debugging against gdbserver in extended-remote mode, and you do "add-inferior" to prepare to spawn a new process, like: (gdb) target extended-remote :9999 ... (gdb) start ... (gdb) add-inferior Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) file a.out ... (gdb) start ... At this point, you have two inferiors connected to the same gdbserver. With this commit, GDB will maintain a target stack per inferior, instead of a global target stack. To preserve the behavior above, by default, "add-inferior" makes the new inferior inherit a copy of the target stack of the current inferior. Same across a fork - the child inherits a copy of the target stack of the parent. While the target stacks are copied, the targets themselves are not. Instead, target_ops is made a refcounted_object, which means that target_ops instances are refcounted, which each inferior counting for a reference. What if you want to create an inferior and connect it to some _other_ target? For that, this commit introduces a new "add-inferior -no-connection" option that makes the new inferior not share the current inferior's target. So you could do: (gdb) target extended-remote :9999 Remote debugging using :9999 ... (gdb) add-inferior -no-connection [New inferior 2] Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 <null> (gdb) tar extended-remote :10000 Remote debugging using :10000 ... (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 process 18450 target:/home/pedro/tmp/main (gdb) A following patch will extended "info inferiors" to include a column indicating which connection an inferior is bound to, along with a couple other UI tweaks. Other than that, debugging is the same as before. Users interact with inferiors and threads as before. The only difference is that inferiors may be bound to processes running in different machines. That's pretty much all there is to it in terms of noticeable UI changes. On to implementation. Since we can be connected to different systems at the same time, a ptid_t is no longer a unique identifier. Instead a thread can be identified by a pair of ptid_t and 'process_stratum_target *', the later being the instance of the process_stratum target that owns the process/thread. Note that process_stratum_target inherits from target_ops, and all process_stratum targets inherit from process_stratum_target. In earlier patches, many places in gdb were converted to refer to threads by thread_info pointer instead of ptid_t, but there are still places in gdb where we start with a pid/tid and need to find the corresponding inferior or thread_info objects. So you'll see in the patch many places adding a process_stratum_target parameter to functions that used to take only a ptid_t. Since each inferior has its own target stack now, we can always find the process_stratum target for an inferior. That is done via a inf->process_target() convenience method. Since each inferior has its own target stack, we need to handle the "beneath" calls when servicing target calls. The solution I settled with is just to make sure to switch the current inferior to the inferior you want before making a target call. Not relying on global context is just not feasible in current GDB. Fortunately, there aren't that many places that need to do that, because generally most code that calls target methods already has the current context pointing to the right inferior/thread. Note, to emphasize -- there's no method to "switch to this target stack". Instead, you switch the current inferior, and that implicitly switches the target stack. In some spots, we need to iterate over all inferiors so that we reach all target stacks. Native targets are still singletons. There's always only a single instance of such targets. Remote targets however, we'll have one instance per remote connection. The exec target is still a singleton. There's only one instance. I did not see the point of instanciating more than one exec_target object. After vfork, we need to make sure to push the exec target on the new inferior. See exec_on_vfork. For type safety, functions that need a {target, ptid} pair to identify a thread, take a process_stratum_target pointer for target parameter instead of target_ops *. Some shared code in gdb/nat/ also need to gain a target pointer parameter. This poses an issue, since gdbserver doesn't have process_stratum_target, only target_ops. To fix this, this commit renames gdbserver's target_ops to process_stratum_target. I think this makes sense. There's no concept of target stack in gdbserver, and gdbserver's target_ops really implements a process_stratum-like target. The thread and inferior iterator functions also gain process_stratum_target parameters. These are used to be able to iterate over threads and inferiors of a given target. Following usual conventions, if the target pointer is null, then we iterate over threads and inferiors of all targets. I tried converting "add-inferior" to the gdb::option framework, as a preparatory patch, but that stumbled on the fact that gdb::option does not support file options yet, for "add-inferior -exec". I have a WIP patchset that adds that, but it's not a trivial patch, mainly due to need to integrate readline's filename completion, so I deferred that to some other time. In infrun.c/infcmd.c, the main change is that we need to poll events out of all targets. See do_target_wait. Right after collecting an event, we switch the current inferior to an inferior bound to the target that reported the event, so that target methods can be used while handling the event. This makes most of the code transparent to multi-targets. See fetch_inferior_event. infrun.c:stop_all_threads is interesting -- in this function we need to stop all threads of all targets. What the function does is send an asynchronous stop request to all threads, and then synchronously waits for events, with target_wait, rinse repeat, until all it finds are stopped threads. Now that we have multiple targets, it's not efficient to synchronously block in target_wait waiting for events out of one target. Instead, we implement a mini event loop, with interruptible_select, select'ing on one file descriptor per target. For this to work, we need to be able to ask the target for a waitable file descriptor. Such file descriptors already exist, they are the descriptors registered in the main event loop with add_file_handler, inside the target_async implementations. This commit adds a new target_async_wait_fd target method that just returns the file descriptor in question. See wait_one / stop_all_threads in infrun.c. The 'threads_executing' global is made a per-target variable. Since it is only relevant to process_stratum_target targets, this is where it is put, instead of in target_ops. You'll notice that remote.c includes some FIXME notes. These refer to the fact that the global arrays that hold data for the remote packets supported are still globals. For example, if we connect to two different servers/stubs, then each might support different remote protocol features. They might even be different architectures, like e.g., one ARM baremetal stub, and a x86 gdbserver, to debug a host/controller scenario as a single program. That isn't going to work correctly today, because of said globals. I'm leaving fixing that for another pass, since it does not appear to be trivial, and I'd rather land the base work first. It's already useful to be able to debug multiple instances of the same server (e.g., a distributed cluster, where you have full control over the servers installed), so I think as is it's already reasonable incremental progress. Current limitations: - You can only resume more that one target at the same time if all targets support asynchronous debugging, and support non-stop mode. It should be possible to support mixed all-stop + non-stop backends, but that is left for another time. This means that currently in order to do multi-target with gdbserver you need to issue "maint set target-non-stop on". I would like to make that mode be the default, but we're not there yet. Note that I'm talking about how the target backend works, only. User-visible all-stop mode works just fine. - As explained above, connecting to different remote servers at the same time is likely to produce bad results if they don't support the exact set of RSP features. FreeBSD updates courtesy of John Baldwin. gdb/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> John Baldwin <jhb@FreeBSD.org> * aarch64-linux-nat.c (aarch64_linux_nat_target::thread_architecture): Adjust. * ada-tasks.c (print_ada_task_info): Adjust find_thread_ptid call. (task_command_1): Likewise. * aix-thread.c (sync_threadlists, aix_thread_target::resume) (aix_thread_target::wait, aix_thread_target::fetch_registers) (aix_thread_target::store_registers) (aix_thread_target::thread_alive): Adjust. * amd64-fbsd-tdep.c: Include "inferior.h". (amd64fbsd_get_thread_local_address): Pass down target. * amd64-linux-nat.c (ps_get_thread_area): Use ps_prochandle thread's gdbarch instead of target_gdbarch. * break-catch-sig.c (signal_catchpoint_print_it): Adjust call to get_last_target_status. * break-catch-syscall.c (print_it_catch_syscall): Likewise. * breakpoint.c (breakpoints_should_be_inserted_now): Consider all inferiors. (update_inserted_breakpoint_locations): Skip if inferiors with no execution. (update_global_location_list): When handling moribund locations, find representative inferior for location's pspace, and use thread count of its process_stratum target. * bsd-kvm.c (bsd_kvm_target_open): Pass target down. * bsd-uthread.c (bsd_uthread_target::wait): Use as_process_stratum_target and adjust thread_change_ptid and add_thread calls. (bsd_uthread_target::update_thread_list): Use as_process_stratum_target and adjust find_thread_ptid, thread_change_ptid and add_thread calls. * btrace.c (maint_btrace_packet_history_cmd): Adjust find_thread_ptid call. * corelow.c (add_to_thread_list): Adjust add_thread call. (core_target_open): Adjust add_thread_silent and thread_count calls. (core_target::pid_to_str): Adjust find_inferior_ptid call. * ctf.c (ctf_target_open): Adjust add_thread_silent call. * event-top.c (async_disconnect): Pop targets from all inferiors. * exec.c (add_target_sections): Push exec target on all inferiors sharing the program space. (remove_target_sections): Remove the exec target from all inferiors sharing the program space. (exec_on_vfork): New. * exec.h (exec_on_vfork): Declare. * fbsd-nat.c (fbsd_add_threads): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::update_thread_list): Adjust. (fbsd_nat_target::resume): Adjust. (fbsd_handle_debug_trap): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::wait, fbsd_nat_target::post_attach): Adjust. * fbsd-tdep.c (fbsd_corefile_thread): Adjust get_thread_arch_regcache call. * fork-child.c (gdb_startup_inferior): Pass target down to startup_inferior and set_executing. * gdbthread.h (struct process_stratum_target): Forward declare. (add_thread, add_thread_silent, add_thread_with_info) (in_thread_list): Add process_stratum_target parameter. (find_thread_ptid(inferior*, ptid_t)): New overload. (find_thread_ptid, thread_change_ptid): Add process_stratum_target parameter. (all_threads()): Delete overload. (all_threads, all_non_exited_threads): Add process_stratum_target parameter. (all_threads_safe): Use brace initialization. (thread_count): Add process_stratum_target parameter. (set_resumed, set_running, set_stop_requested, set_executing) (threads_are_executing, finish_thread_state): Add process_stratum_target parameter. (switch_to_thread): Use is_current_thread. * i386-fbsd-tdep.c: Include "inferior.h". (i386fbsd_get_thread_local_address): Pass down target. * i386-linux-nat.c (i386_linux_nat_target::low_resume): Adjust. * inf-child.c (inf_child_target::maybe_unpush_target): Remove have_inferiors check. * inf-ptrace.c (inf_ptrace_target::create_inferior) (inf_ptrace_target::attach): Adjust. * infcall.c (run_inferior_call): Adjust. * infcmd.c (run_command_1): Pass target to scoped_finish_thread_state. (proceed_thread_callback): Skip inferiors with no execution. (continue_command): Rename 'all_threads' local to avoid hiding 'all_threads' function. Adjust get_last_target_status call. (prepare_one_step): Adjust set_running call. (signal_command): Use user_visible_resume_target. Compare thread pointers instead of inferior_ptid. (info_program_command): Adjust to pass down target. (attach_command): Mark target's 'thread_executing' flag. (stop_current_target_threads_ns): New, factored out from ... (interrupt_target_1): ... this. Switch inferior before making target calls. * inferior-iter.h (struct all_inferiors_iterator, struct all_inferiors_range) (struct all_inferiors_safe_range) (struct all_non_exited_inferiors_range): Filter on process_stratum_target too. Remove explicit. * inferior.c (inferior::inferior): Push dummy target on target stack. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors): Add process_stratum_target parameter, and pass it down. (have_live_inferiors): Adjust. (switch_to_inferior_and_push_target): New. (add_inferior_command, clone_inferior_command): Handle "-no-connection" parameter. Use switch_to_inferior_and_push_target. (_initialize_inferior): Mention "-no-connection" option in the help of "add-inferior" and "clone-inferior" commands. * inferior.h: Include "process-stratum-target.h". (interrupt_target_1): Use bool. (struct inferior) <push_target, unpush_target, target_is_pushed, find_target_beneath, top_target, process_target, target_at, m_stack>: New. (discard_all_inferiors): Delete. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors) (all_inferiors, all_non_exited_inferiors): Add process_stratum_target parameter. * infrun.c: Include "gdb_select.h" and <unordered_map>. (target_last_proc_target): New global. (follow_fork_inferior): Push target on new inferior. Pass target to add_thread_silent. Call exec_on_vfork. Handle target's reference count. (follow_fork): Adjust get_last_target_status call. Also consider target. (follow_exec): Push target on new inferior. (struct execution_control_state) <target>: New field. (user_visible_resume_target): New. (do_target_resume): Call target_async. (resume_1): Set target's threads_executing flag. Consider resume target. (commit_resume_all_targets): New. (proceed): Also consider resume target. Skip threads of inferiors with no execution. Commit resumtion in all targets. (start_remote): Pass current inferior to wait_for_inferior. (infrun_thread_stop_requested): Consider target as well. Pass thread_info pointer to clear_inline_frame_state instead of ptid. (infrun_thread_thread_exit): Consider target as well. (random_pending_event_thread): New inferior parameter. Use it. (do_target_wait): Rename to ... (do_target_wait_1): ... this. Add inferior parameter, and pass it down. (threads_are_resumed_pending_p, do_target_wait): New. (prepare_for_detach): Adjust calls. (wait_for_inferior): New inferior parameter. Handle it. Use do_target_wait_1 instead of do_target_wait. (fetch_inferior_event): Adjust. Switch to representative inferior. Pass target down. (set_last_target_status): Add process_stratum_target parameter. Save target in global. (get_last_target_status): Add process_stratum_target parameter and handle it. (nullify_last_target_wait_ptid): Clear 'target_last_proc_target'. (context_switch): Check inferior_ptid == null_ptid before calling inferior_thread(). (get_inferior_stop_soon): Pass down target. (wait_one): Rename to ... (poll_one_curr_target): ... this. (struct wait_one_event): New. (wait_one): New. (stop_all_threads): Adjust. (handle_no_resumed, handle_inferior_event): Adjust to consider the event's target. (switch_back_to_stepped_thread): Also consider target. (print_stop_event): Update. (normal_stop): Update. Also consider the resume target. * infrun.h (wait_for_inferior): Remove declaration. (user_visible_resume_target): New declaration. (get_last_target_status, set_last_target_status): New process_stratum_target parameter. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter, and use it. (clear_inline_frame_state (thread_info*)): New. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter. (clear_inline_frame_state (thread_info*)): Declare. * linux-fork.c (delete_checkpoint_command): Pass target down to find_thread_ptid. (checkpoint_command): Adjust. * linux-nat.c (linux_nat_target::follow_fork): Switch to thread instead of just tweaking inferior_ptid. (linux_nat_switch_fork): Pass target down to thread_change_ptid. (exit_lwp): Pass target down to find_thread_ptid. (attach_proc_task_lwp_callback): Pass target down to add_thread/set_running/set_executing. (linux_nat_target::attach): Pass target down to thread_change_ptid. (get_detach_signal): Pass target down to find_thread_ptid. Consider last target status's target. (linux_resume_one_lwp_throw, resume_lwp) (linux_handle_syscall_trap, linux_handle_extended_wait, wait_lwp) (stop_wait_callback, save_stop_reason, linux_nat_filter_event) (linux_nat_wait_1, resume_stopped_resumed_lwps): Pass target down. (linux_nat_target::async_wait_fd): New. (linux_nat_stop_lwp, linux_nat_target::thread_address_space): Pass target down. * linux-nat.h (linux_nat_target::async_wait_fd): Declare. * linux-tdep.c (get_thread_arch_regcache): Pass target down. * linux-thread-db.c (struct thread_db_info::process_target): New field. (add_thread_db_info): Save target. (get_thread_db_info): New process_stratum_target parameter. Also match target. (delete_thread_db_info): New process_stratum_target parameter. Also match target. (thread_from_lwp): Adjust to pass down target. (thread_db_notice_clone): Pass down target. (check_thread_db_callback): Pass down target. (try_thread_db_load_1): Always push the thread_db target. (try_thread_db_load, record_thread): Pass target down. (thread_db_target::detach): Pass target down. Always unpush the thread_db target. (thread_db_target::wait, thread_db_target::mourn_inferior): Pass target down. Always unpush the thread_db target. (find_new_threads_callback, thread_db_find_new_threads_2) (thread_db_target::update_thread_list): Pass target down. (thread_db_target::pid_to_str): Pass current inferior down. (thread_db_target::get_thread_local_address): Pass target down. (thread_db_target::resume, maintenance_check_libthread_db): Pass target down. * nto-procfs.c (nto_procfs_target::update_thread_list): Adjust. * procfs.c (procfs_target::procfs_init_inferior): Declare. (proc_set_current_signal, do_attach, procfs_target::wait): Adjust. (procfs_init_inferior): Rename to ... (procfs_target::procfs_init_inferior): ... this and adjust. (procfs_target::create_inferior, procfs_notice_thread) (procfs_do_thread_registers): Adjust. * ppc-fbsd-tdep.c: Include "inferior.h". (ppcfbsd_get_thread_local_address): Pass down target. * proc-service.c (ps_xfer_memory): Switch current inferior and program space as well. (get_ps_regcache): Pass target down. * process-stratum-target.c (process_stratum_target::thread_address_space) (process_stratum_target::thread_architecture): Pass target down. * process-stratum-target.h (process_stratum_target::threads_executing): New field. (as_process_stratum_target): New. * ravenscar-thread.c (ravenscar_thread_target::update_inferior_ptid): Pass target down. (ravenscar_thread_target::wait, ravenscar_add_thread): Pass target down. * record-btrace.c (record_btrace_target::info_record): Adjust. (record_btrace_target::record_method) (record_btrace_target::record_is_replaying) (record_btrace_target::fetch_registers) (get_thread_current_frame_id, record_btrace_target::resume) (record_btrace_target::wait, record_btrace_target::stop): Pass target down. * record-full.c (record_full_wait_1): Switch to event thread. Pass target down. * regcache.c (regcache::regcache) (get_thread_arch_aspace_regcache, get_thread_arch_regcache): Add process_stratum_target parameter and handle it. (current_thread_target): New global. (get_thread_regcache): Add process_stratum_target parameter and handle it. Switch inferior before calling target method. (get_thread_regcache): Pass target down. (get_thread_regcache_for_ptid): Pass target down. (registers_changed_ptid): Add process_stratum_target parameter and handle it. (registers_changed_thread, registers_changed): Pass target down. (test_get_thread_arch_aspace_regcache): New. (current_regcache_test): Define a couple local test_target_ops instances and use them for testing. (readwrite_regcache): Pass process_stratum_target parameter. (cooked_read_test, cooked_write_test): Pass mock_target down. * regcache.h (get_thread_regcache, get_thread_arch_regcache) (get_thread_arch_aspace_regcache): Add process_stratum_target parameter. (regcache::target): New method. (regcache::regcache, regcache::get_thread_arch_aspace_regcache) (regcache::registers_changed_ptid): Add process_stratum_target parameter. (regcache::m_target): New field. (registers_changed_ptid): Add process_stratum_target parameter. * remote.c (remote_state::supports_vCont_probed): New field. (remote_target::async_wait_fd): New method. (remote_unpush_and_throw): Add remote_target parameter. (get_current_remote_target): Adjust. (remote_target::remote_add_inferior): Push target. (remote_target::remote_add_thread) (remote_target::remote_notice_new_inferior) (get_remote_thread_info): Pass target down. (remote_target::update_thread_list): Skip threads of inferiors bound to other targets. (remote_target::close): Don't discard inferiors. (remote_target::add_current_inferior_and_thread) (remote_target::process_initial_stop_replies) (remote_target::start_remote) (remote_target::remote_serial_quit_handler): Pass down target. (remote_target::remote_unpush_target): New remote_target parameter. Unpush the target from all inferiors. (remote_target::remote_unpush_and_throw): New remote_target parameter. Pass it down. (remote_target::open_1): Check whether the current inferior has execution instead of checking whether any inferior is live. Pass target down. (remote_target::remote_detach_1): Pass down target. Use remote_unpush_target. (extended_remote_target::attach): Pass down target. (remote_target::remote_vcont_probe): Set supports_vCont_probed. (remote_target::append_resumption): Pass down target. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc, remote_target::resume) (remote_target::commit_resume): Pass down target. (remote_target::remote_stop_ns): Check supports_vCont_probed. (remote_target::interrupt_query) (remote_target::remove_new_fork_children) (remote_target::check_pending_events_prevent_wildcard_vcont) (remote_target::remote_parse_stop_reply) (remote_target::process_stop_reply): Pass down target. (first_remote_resumed_thread): New remote_target parameter. Pass it down. (remote_target::wait_as): Pass down target. (unpush_and_perror): New remote_target parameter. Pass it down. (remote_target::readchar, remote_target::remote_serial_write) (remote_target::getpkt_or_notif_sane_1) (remote_target::kill_new_fork_children, remote_target::kill): Pass down target. (remote_target::mourn_inferior): Pass down target. Use remote_unpush_target. (remote_target::core_of_thread) (remote_target::remote_btrace_maybe_reopen): Pass down target. (remote_target::pid_to_exec_file) (remote_target::thread_handle_to_thread_info): Pass down target. (remote_target::async_wait_fd): New. * riscv-fbsd-tdep.c: Include "inferior.h". (riscv_fbsd_get_thread_local_address): Pass down target. * sol2-tdep.c (sol2_core_pid_to_str): Pass down target. * sol-thread.c (sol_thread_target::wait, ps_lgetregs, ps_lsetregs) (ps_lgetfpregs, ps_lsetfpregs, sol_update_thread_list_callback): Adjust. * solib-spu.c (spu_skip_standalone_loader): Pass down target. * solib-svr4.c (enable_break): Pass down target. * spu-multiarch.c (parse_spufs_run): Pass down target. * spu-tdep.c (spu2ppu_sniffer): Pass down target. * target-delegates.c: Regenerate. * target.c (g_target_stack): Delete. (current_top_target): Return the current inferior's top target. (target_has_execution_1): Refer to the passed-in inferior's top target. (target_supports_terminal_ours): Check whether the initial inferior was already created. (decref_target): New. (target_stack::push): Incref/decref the target. (push_target, push_target, unpush_target): Adjust. (target_stack::unpush): Defref target. (target_is_pushed): Return bool. Adjust to refer to the current inferior's target stack. (dispose_inferior): Delete, and inline parts ... (target_preopen): ... here. Only dispose of the current inferior. (target_detach): Hold strong target reference while detaching. Pass target down. (target_thread_name): Add assertion. (target_resume): Pass down target. (target_ops::beneath, find_target_at): Adjust to refer to the current inferior's target stack. (get_dummy_target): New. (target_pass_ctrlc): Pass the Ctrl-C to the first inferior that has a thread running. (initialize_targets): Rename to ... (_initialize_target): ... this. * target.h: Include "gdbsupport/refcounted-object.h". (struct target_ops): Inherit refcounted_object. (target_ops::shortname, target_ops::longname): Make const. (target_ops::async_wait_fd): New method. (decref_target): Declare. (struct target_ops_ref_policy): New. (target_ops_ref): New typedef. (get_dummy_target): Declare function. (target_is_pushed): Return bool. * thread-iter.c (all_matching_threads_iterator::m_inf_matches) (all_matching_threads_iterator::all_matching_threads_iterator): Handle filter target. * thread-iter.h (struct all_matching_threads_iterator, struct all_matching_threads_range, class all_non_exited_threads_range): Filter by target too. Remove explicit. * thread.c (threads_executing): Delete. (inferior_thread): Pass down current inferior. (clear_thread_inferior_resources): Pass down thread pointer instead of ptid_t. (add_thread_silent, add_thread_with_info, add_thread): Add process_stratum_target parameter. Use it for thread and inferior searches. (is_current_thread): New. (thread_info::deletable): Use it. (find_thread_ptid, thread_count, in_thread_list) (thread_change_ptid, set_resumed, set_running): New process_stratum_target parameter. Pass it down. (set_executing): New process_stratum_target parameter. Pass it down. Adjust reference to 'threads_executing'. (threads_are_executing): New process_stratum_target parameter. Adjust reference to 'threads_executing'. (set_stop_requested, finish_thread_state): New process_stratum_target parameter. Pass it down. (switch_to_thread): Also match inferior. (switch_to_thread): New process_stratum_target parameter. Pass it down. (update_threads_executing): Reimplement. * top.c (quit_force): Pop targets from all inferior. (gdb_init): Don't call initialize_targets. * windows-nat.c (windows_nat_target) <get_windows_debug_event>: Declare. (windows_add_thread, windows_delete_thread): Adjust. (get_windows_debug_event): Rename to ... (windows_nat_target::get_windows_debug_event): ... this. Adjust. * tracefile-tfile.c (tfile_target_open): Pass down target. * gdbsupport/common-gdbthread.h (struct process_stratum_target): Forward declare. (switch_to_thread): Add process_stratum_target parameter. * mi/mi-interp.c (mi_on_resume_1): Add process_stratum_target parameter. Use it. (mi_on_resume): Pass target down. * nat/fork-inferior.c (startup_inferior): Add process_stratum_target parameter. Pass it down. * nat/fork-inferior.h (startup_inferior): Add process_stratum_target parameter. * python/py-threadevent.c (py_get_event_thread): Pass target down. gdb/gdbserver/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> * fork-child.c (post_fork_inferior): Pass target down to startup_inferior. * inferiors.c (switch_to_thread): Add process_stratum_target parameter. * lynx-low.c (lynx_target_ops): Now a process_stratum_target. * nto-low.c (nto_target_ops): Now a process_stratum_target. * linux-low.c (linux_target_ops): Now a process_stratum_target. * remote-utils.c (prepare_resume_reply): Pass the target to switch_to_thread. * target.c (the_target): Now a process_stratum_target. (done_accessing_memory): Pass the target to switch_to_thread. (set_target_ops): Ajust to use process_stratum_target. * target.h (struct target_ops): Rename to ... (struct process_stratum_target): ... this. (the_target, set_target_ops): Adjust. (prepare_to_access_memory): Adjust comment. * win32-low.c (child_xfer_memory): Adjust to use process_stratum_target. (win32_target_ops): Now a process_stratum_target.
2020-01-10Make target_ops::has_execution take an 'inferior *' instead of a ptid_tPedro Alves1-3/+4
With the multi-target work, each inferior will have its own target stack, so to call a target method, we'll need to make sure that the inferior in question is the current one, otherwise target->beneath() calls will find the target beneath in the wrong inferior. In some places, it's much more convenient to be able to check whether an inferior has execution without having to switch to it in order to call target_has_execution on the right inferior/target stack, to avoid side effects with switching inferior/thread/program space. The current target_ops::has_execution method takes a ptid_t as parameter, which, in a multi-target world, isn't sufficient to identify the target. This patch prepares to address that, by changing the parameter to an inferior pointer instead. From the inferior, we'll be able to query its target stack to tell which target is beneath. Also adds a new inferior::has_execution() method to make callers a bit more natural to read. gdb/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> * corelow.c (core_target::has_execution): Change parameter type to inferior pointer. * inferior.c (number_of_live_inferiors): Use inferior::has_execution instead of target_has_execution_1. * inferior.h (inferior::has_execution): New. * linux-thread-db.c (thread_db_target::update_thread_list): Use inferior::has_execution instead of target_has_execution_1. * process-stratum-target.c (process_stratum_target::has_execution): Change parameter type to inferior pointer. Check the inferior's PID instead of inferior_ptid. * process-stratum-target.h (process_stratum_target::has_execution): Change parameter type to inferior pointer. * record-full.c (record_full_core_target::has_execution): Change parameter type to inferior pointer. * target.c (target_has_execution_1): Change parameter type to inferior pointer. (target_has_execution_current): Adjust. * target.h (target_ops::has_execution): Change parameter type to inferior pointer. (target_has_execution_1): Change parameter type to inferior pointer. Change return type to bool. * tracefile.h (tracefile_target::has_execution): Change parameter type to inferior pointer.
2020-01-10Don't rely on inferior_ptid in record_full_waitPedro Alves1-0/+7
The multi-target patch sets inferior_ptid to null_ptid before handling a target event, and thus before calling target_wait, in order to catch places in target_ops::wait implementations that are incorrectly relying on inferior_ptid (which could otherwise be a ptid of a different target, for example). That caught this instance in record-full.c. Fix it by saving the last resumed ptid, and then using it in record_full_wait_1, just like how the last "step" argument passed to record_full_target::resume is handled too. gdb/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> * record-full.c (record_full_resume_ptid): New global. (record_full_target::resume): Set it. (record_full_wait_1): Use record_full_resume_ptid instead of inferior_ptid.
2020-01-02Remove stale references to Cell BELuis Machado1-5/+4
While reading some code i noticed we're still referencing Cell BE in a couple parts. This patch removes those. v2: Update comment in gdb/target.h. gdb/ChangeLog: 2020-01-02 Luis Machado <luis.machado@linaro.org> * proc-service.c (get_ps_regcache): Remove reference to obsolete Cell BE architecture. * target.h (struct target_ops) <thread_architecture>: Likewise. Change-Id: I7a9ccc603b00db22a6275bc5ab69e1417148cb72
2020-01-01Update copyright year range in all GDB files.Joel Brobecker1-1/+1
gdb/ChangeLog: Update copyright year range in all GDB files.
2019-10-15gdb: Update comments that reference VEC or vec.hAndrew Burgess1-1/+1
With the removal of the old VEC mechanism from the code base, update comments that still make reference to VECs. There should be no user visible changes after this commit. gdb/ChangeLog: * linespec.c (decode_digits_ordinary): Update comment. * make-target-delegates: No longer need to handle VEC case. * memrange.c (normalize_mem_ranges): Update comment. * namespace.c (add_using_directive): Update comment. * objc-lang.c (uniquify_strings): Update comment. * ppc-linux-nat.c (struct thread_points): Update comment. * probe.h (find_probes_in_objfile): Update comment. * target.h (enum flash_preserve_mode): Update comment. * varobj.c (varobj_restrict_range): Update comment. * varobj.h (varobj_list_children): Update comment. Change-Id: Iefd2e903705c3e79cd13b43395c7a1c167f9a088
2019-10-15gdb: Remove vec.{c,h} and update code to not include vec.hAndrew Burgess1-1/+0
Removes vec.c and vec.h from the source tree, and remove all the remaining includes of vec.h. There should be no user visible changes after this commit. I did have a few issues rebuilding GDB after applying this patch due to cached dependencies, I found that running this command in the build directory resolved my build issues without requiring a 'make clean': rm -fr gdb/gdbserver/gdbsupport/.deps/ gdb/ChangeLog: * Makefile.in: Remove references to vec.h and vec.c. * aarch64-tdep.c: No longer include vec.h. * ada-lang.c: Likewise. * ada-lang.h: Likewise. * arm-tdep.c: Likewise. * ax.h: Likewise. * breakpoint.h: Likewise. * charset.c: Likewise. * cp-support.h: Likewise. * dtrace-probe.c: Likewise. * dwarf2read.c: Likewise. * extension.h: Likewise. * gdb_bfd.c: Likewise. * gdbsupport/gdb_vecs.h: Likewise. * gdbsupport/vec.c: Remove. * gdbsupport/vec.h: Remove. * gdbthread.h: Likewise. * guile/scm-type.c: Likewise. * inline-frame.c: Likewise. * machoread.c: Likewise. * memattr.c: Likewise. * memrange.h: Likewise. * namespace.h: Likewise. * nat/linux-btrace.h: Likewise. * osdata.c: Likewise. * parser-defs.h: Likewise. * progspace.h: Likewise. * python/py-type.c: Likewise. * record-btrace.c: Likewise. * rust-exp.y: Likewise. * solib-target.c: Likewise. * stap-probe.c: Likewise. * target-descriptions.c: Likewise. * target-memory.c: Likewise. * target.h: Likewise. * varobj.c: Likewise. * varobj.h: Likewise. * xml-support.h: Likewise. gdb/gdbserver/ChangeLog: * Makefile.in: Remove references to vec.c. Change-Id: I0c91d7170bf1b5e992a387fcd9fe4f2abe343bb5