Miscellaneous non-functional changes to prepare for adding support for
follow-exec mode on Windows:
- removed (*nativeProcess).wait function from Windows backend (unused).
- move close of ptraceDoneChan from release to handlePtraceFuncs, this
makes postExit callable by a function executed by execPtraceFunc.
- change addTarget to detach before creating the target object if we
don't actually want to attach to the child process, also moved the
detach call to (*processGroup).add instead of having one in addTarget
and one in the code that calls (*processGroup).add.
- changed Detach to be a method of TargetGroup/ProcessGroup, the
Windows backend will need access to the process group to call
WaitForDebugEvent.
- moved resume method to processGroup. First all threads stopped at a
breakpoint need to be stepped, then all other threads can be resumed.
This is true also for linux even though it didn't cause the current
tests to fail.
Adds a waitfor option to 'dlv attach' that waits for a process with a
name starting with a given prefix to appear before attaching to it.
Debugserver on macOS does not support follow-fork mode, but has this
feature instead which is not the same thing but still helps with
multiprocess debugging somewhat.
Read the command line of the main target process as well as any other
process Delve attaches to in follow exec mode.
The command line can be viewed using the 'target list' command.
In follow exec mode this command line is used to match the follow exec
regex to decide whether or not to attach to a child process.
On macOS or when using rr the list of arguments is not available for
attached processes since there is no way to use the gdb serial protocol
to read it.
Fixes#2242
Adds the ability to automatically debug child processes executed by the
target to the linux native backend.
This commit does not contain user interface or API to access this
functionality.
Updates #2551
* made Pid a method of Target instead of a method of Process
* changed argument of NewTarget to ProcessInternal, since that's the
interface that backends have to implement
* removed warnings about ProcessInternal since there is no way for
users of pkg/proc to access those methods anyway
* made RecordingManipulation an optional interface for backends, Target
supplies its own dummy implementation when the backend doesn't
* inlined small interfaces that only existed to be inlined in
proc.Process anyway
* removed unused function findExecutable in the Windows and no-native
darwin backends
* removed (*EvalScope).EvalVariable, an old synonym for EvalExpression
This patch enables the eBPF tracer backend to parse the ID of the
Goroutine which hit the uprobe. This implementation is specific to AMD64
and will have to be generalized further in order to be used on other
architectures.
We have some places where we use proc.ErrProcessExited and some places
that use &proc.ErrProcessExited, resulting in checks for process exited
errors occasionally failing on some architectures.
Uniform use of ErrProcessExited to the non-pointer version.
Fixes intermittent failure of TestStepOutPreservesGoroutine.
On linux we can not read memory if the thread we use to do it is
occupied doing certain system calls. The exact conditions when this
happens have never been clear.
This problem was worked around by using the Blocked method which
recognized the most common circumstances where this would happen.
However this is a hack: Blocked returning true doesn't mean that the
problem will manifest and Blocked returning false doesn't necessarily
mean the problem will not manifest. A side effect of this is issue
#2151 where sometimes we can't read the memory of a thread and find its
associated goroutine.
This commit fixes this problem by always reading memory using a thread
we know to be good for this, specifically the one returned by
ContinueOnce. In particular the changes are as follows:
1. Remove (ProcessInternal).CurrentThread and
(ProcessInternal).SetCurrentThread, the "current thread" becomes a
field of Target, CurrentThread becomes a (*Target) method and
(*Target).SwitchThread basically just sets a field Target.
2. The backends keep track of their own internal idea of what the
current thread is, to use it to read memory, this is the thread they
return from ContinueOnce as trapthread
3. The current thread in the backend and the current thread in Target
only ever get synchronized in two places: when the backend creates a
Target object the currentThread field of Target is initialized with the
backend's current thread and when (*Target).Restart gets called (when a
recording is rewound the currentThread used by Target might not exist
anymore).
4. We remove the MemoryReadWriter interface embedded in Thread and
instead add a Memory method to Process that returns a MemoryReadWriter.
The backends will return something here that will read memory using
the current thread saved by the backend.
5. The Thread.Blocked method is removed
One possible problem with this change is processes that have threads
with different memory maps. As far as I can determine this could happen
on old versions of linux but this option was removed in linux 2.5.
Fixes#2151
TestStepConcurrentDirect will occasionally fail (7% of the time on my
setup) by either causing the target processs to execute an invalid
instruction or (more infrequently) by switching to the wrong thread.
Both of those are caused by receiving SIGTRAPs for threads hitting a
breakpoint after it has been removed (the thread hits the breakpoint,
we stop everything and remove the breakpoint and only after we receive
the signal).
Change native.(*nativeProcess).stop to handle SIGTRAPs that can't be
attributed to a breakpoint, a hardcoded breakpoint in the program's
text, or manual stops (and therefore are likely caused by phantom
breakpoint hits).
Co-authored-by: a <a@kra>
Adds features to support default file descriptor redirects for the
target process:
1. A new command line flag '--redirect' and '-r' are added to specify
file redirects for the target process
2. New syntax is added to the 'restart' command to specify file
redirects.
3. Interactive instances will check if stdin/stdout and stderr are
terminals and print a helpful error message if they aren't.
This flag allows users on UNIX systems to set the tty for the program
being debugged by Delve. This is useful for debugging command line
applications which need access to their own TTY, and also for
controlling the output of the debugged programs so that IDEs may open a
dedicated terminal to show the output for the process.
* proc,proc/*: move SelectedGoroutine to proc.Target, remove PostInitializationSetup
moves SelectedGoroutine, SwitchThread and SwitchGoroutine to
proc.Target, merges PostInitializationSetup with NewTarget.
* proc,proc/*: add StopReason field to Target
Adds a StopReason field to the Target object describing why the target
process is currently stopped. This will be useful for the DAP server
(which needs to report this reason in one of its requests) as well as
making pull request #1785 (reverse step) conformant to the new
architecture.
* proc: collect NewTarget arguments into a struct
* tests: misc test fixes for go1.14
- math.go is now ambiguous due to changes to the go runtime so specify
that we mean our own math.go in _fixtures
- go list -m requires vendor-mode to be disabled so pass '-mod=' to it
in case user has GOFLAGS=-mod=vendor
- update version of go/packages, required to work with go 1.14 (and
executed go mod vendor)
- Increased goroutine migration in one development version of Go 1.14
revealed a problem with TestCheckpoints in command_test.go and
rr_test.go. The tests were always wrong because Restart(checkpoint)
doesn't change the current thread but we can't assume that when the
checkpoint was taken the current goroutine was running on the same
thread.
* goversion: update maximum supported version
* Makefile: disable testing lldb-server backend on linux with Go 1.14
There seems to be some incompatibility with lldb-server version 6.0.0
on linux and Go 1.14.
* proc/gdbserial: better handling of signals
- if multiple signals are received simultaneously propagate all of them to the
target threads instead of only one.
- debugserver will drop an interrupt request if a target thread simultaneously
receives a signal, handle this situation.
* dwarf/line: normalize backslashes for windows executables
Starting with Go 1.14 the compiler sometimes emits backslashes as well
as forward slashes in debug_line, normalize everything to / for
conformity with the behavior of previous versions.
* proc/native: partial support for Windows async preempt mechanism
See https://github.com/golang/go/issues/36494 for a description of why
full support for 1.14 under windows is problematic.
* proc/native: disable Go 1.14 async preemption on Windows
See https://github.com/golang/go/issues/36494
* pkg/proc: Introduce Target
* pkg/proc: Remove Common.fncallEnabled
Realistically we only block it on recorded backends.
* pkg/proc: Move fncallForG to Target
* pkg/proc: Remove CommonProcess
Remove final bit of functionality stored in CommonProcess and move it to
*Target.
* pkg/proc: Add SupportsFunctionCall to Target
proc.Next and proc.Step will call, after setting their temp
breakpoints, curthread.SetCurrentBreakpoint. This is intended to find
if one of the newly created breakpoints happens to be at the same
instruction that curthread is stopped at.
However SetCurrentBreakpoint is intended to be called after a Continue
and StepInstruction operation so it will also detect if curthread is
stopped one byte after a breakpoint.
If the instruction immediately preceeding the current instruction of
curthread happens to:
1. have one of the newly created temp breakpoints
2. be one byte long
SetCurrentBreakpoint will believe that we just hit that breakpoint and
therefore the instruction should be repeated, and thus rewind the PC of
curthread by 1.
We should distinguish between the two uses of SetCurrentBreakpoint and
disable the check for "just hit" breakpoints when inappropriate.
Fixes#1656
The repository is being switched from the personal account
github.com/derekparker/delve to the organization account
github.com/go-delve/delve. This patch updates imports and docs, while
preserving things which should not be changed such as my name in the
CHANGELOG and in TODO comments.
This patch is a slight refactor to share more code used for genericprocess initialization. There will always be OS/backend specificinitialization, but as much as can be shared should be to preventduplicating of any logic (setting internal breakpoints, loading bininfo,etc).
Support for position independent executables (PIE) on the native linux
backend, the gdbserver backend on linux and the core backend.
Also implemented in the windows native backend, but it can't be tested
because go doesn't support PIE on windows yet.
On macOS 10.14 Apple changed the command line tools so that system
headers now need to be manually installed.
Instead of adding one extra install step to the install procedure add a
build tag to allow compilation of delve without the native backend on
macOS. By default (i.e. when using `go get`) this is how delve will be
compiled on macOS, the make script is changed to enable compiling the
native backend if the required dependencies have been installed.
Insure that both configuration still build correctly on Travis CI and
change the documentation to describe how to compile the native backend
and that it isn't normally needed.
Fixes#1359
Displays the return values of the current function when we step out of
it after executing a step, next or stepout command.
Implementation of this feature is tricky: when the function has
returned the return variables are not in scope anymore. Implementing
this feature requires evaluating variables that are out of scope, using
a stack frame that doesn't exist anymore.
We can't calculate the address of these variables when the
next/step/stepout command is initiated either, because between that
point and the time where the stepout breakpoint is actually hit the
goroutine stack could grow and be moved to a different memory address.
Change the linux verison of proc/native and proc/gdbserial (with
debugserver) so that they let the target process use the terminal when
delve is launched in headless mode.
Windows already worked, proc/gdbserial (with rr) already worked.
I couldn't find a way to make proc/gdbserial (with lldb-server) work.
No tests are added because I can't think of a way to test for
foregroundness of a process.
Fixes#65
* Handle race between fork and task_for_pid
On macOS a call to fork and a subsequent call to task_for_pid will race each other. This is because the macOS kernel assigns a new proc_t structure early but the new task, thread and uthread come much later. The function exec_mach_imgact in the XNU sources contains this logic.
In a system under load or one with delays in fork processing (i.e. various security software), task_for_pid as currently called by Delve often returns the parent task. This can be seen by printing out the task number around line 86. In a normal system we would see three calls:
-> ~/go/bin/dlv --listen=localhost:59115 --headless=true --api-version=2 --backend=native exec ./___main_go --
Task: 9731
Task: 9731
Task: 9731
API server listening at: 127.0.0.1:59115
This is the result on a system where the race is lost:
-> ~/go/bin/dlv --listen=localhost:59115 --headless=true --api-version=2 --backend=native exec ./___main_go --
Task: 8707
Task: 10499
Task: 10499
could not launch process: could not get thread count
In this latter case, task 8707 is the parent task. The child task of 10499 was desired and hence the error.
This code change checks to make sure the returned task is not that of the parent. If it is, it retries. It's possible other macOS reported Delve issues are the result of this failed race.
* proc: correct formatting
Conditional breakpoints with unmet conditions would cause next and step
to skip the line.
This breakpoint changes the Kind field of proc.Breakpoint from a single
value to a bit field, each breakpoint object can represent
simultaneously a user breakpoint and one internal breakpoint (of which
we have several different kinds).
The breakpoint condition for internal breakpoints is stored in the new
internalCond field of proc.Breakpoint so that it will not conflict with
user specified conditions.
The breakpoint setting code is changed to allow overlapping one
internal breakpoint on a user breakpoint, or a user breakpoint on an
existing internal breakpoint. All other combinations are rejected. The
breakpoint clearing code is changed to clear the UserBreakpoint bit and
only remove the phisical breakpoint if no other bits are set in the
Kind field. ClearInternalBreakpoints does the same thing but clearing
all bits that aren't the UserBreakpoint bit.
Fixes#844
RequestManualStop will run concurrently with trapWait, since one writes
dbp.halt and the other reads it dbp.halt should be protected by a
mutex.
Updates #830
While implementing the gdbserial backend everything was changed to call
Detach to "close" a process so that gdbserial could do its clean up in
a single place. However the native implementation of Detach does not
actually kill processes we launched.
Fixes#821
