There is already a lock on the actual buffered tracepoints collection
within proc, and this method call doesn't do anything to mutate Target
otherwise so we shouldn't be opening ourselves up for a race condition
error or any other kind of parallelism problem.
Additionally, with this lock we essentially can never get the data until
the process has exited becuase `continue` will lock the target. This
change allows us to get the buffered tracepoint information immediately
and display it as the program is running.
The loop searching for a suitable goroutine is not guaranteed to ever
find it, and failing to find one is not an error.
Changes testStepParkedHelper to match the behavior of TestNextParked in
proc_test.go.
Deletes TestStepInParked because it does not test anything meaningful
beyond what's already tested by TestNextParked.
Returning monotonically increasing totalFrames values for subsequent requests can be used to enforce paging in the client. If we are not at the end of the stackFrames that are returned, we return a higher total frames to suggest to the client that they should request more frames.
To make it more clear that the user can resume the program when they encounter a next while nexting error, make the exception information have instructions for resuming the program. This implements the suggestions outlined by @polinasok in #2443.
* pkg/proc: Prefer throw instead of fatalthrow
Currently there is a breakpoint set at runtime.fatalthrow to catch any
situation where the runtime crashes (e.g. deadlock).
When we do this, we go up a frame in order to parse the crash reason.
The problem is that there is no guarentee the "s" variable we attempt to
parse will still be considered "live".
Since runtime.fatalthrow is never called directly, set a breakpoint on
runtime.throw instead and prevent having
to search up a stack frame in order to
get the throw reason.
Fixes#2602
* service/dap: Fix TestFatalThrowBreakpoint
* Reenable TestFatalThrow DAP test
* service/dap: Don't skip test on < 1.17
* service/dap: Update test constraint for 1.16
* pkg/proc: Reinstate runtime.fatalthrow as switchstack exception
Using issue419.go, I observed that the continue command fails with an error when debugger receives and forwards an interrupt. In spite of the stopped event, vscode still shows the state as RUNNING because the threads request is unable to retrieve any threads, but at least one dummy thread is always expected.
Co-authored-by: Polina Sokolova <polinasok@users.noreply.github.com>
This adds a cap and a log message if there are many goroutines. This will help
prevent the debugger from freezing, but does not yet address making sure the
interesting goroutines are the ones that are returned.
Updates golang/vscode-go#129
Changes Breakpoint to allow multiple overlapping internal breakpoints
on the same instruction address.
This is done by changing the Breakpoint structure to contain a list of
"breaklets", each breaklet has a BreakpointKind and a condition
expression, independent of the other.
A breakpoint is considered active if any of its breaklets are active.
A breakpoint is removed when all its breaklets are removed.
We also change the terminology "internal breakpoint" to "stepping
breakpoint":
HasInternalBreakpoints -> HasSteppingBreakpoints
IsInternal -> IsStepping
etc...
The motivation for this change is implementing watchpoints on stack
variables.
Watching a stack variable requires also setting a special breakpoint to
find out when the variable goes out of scope. These breakpoints can not
be UserBreakpoints because only one user breakpoint is allowed on the
same instruction and they can not be internal breakpoints because they
should not be cleared when a next operation is completed (they should
be cleared when the variable watch is cleared).
Updates #279
This PR aims to add support for rr replay and core actions from the DAP layer. This basically encloses the following:
New launch modes: replay and core
The following modes are added:
replay: Replays an rr trace, allowing backwards flows (reverse continue and stepback). Requires a traceDirPath property on launch.json pointing to a valid rr trace directory.
Equivalent to dlv replay <tracedir> command.
core: Replays a core dump file, showing its callstack and the file matching the callsite. Requires a coreFilePath property on launch.json pointing to a valid coredump file.
Equivalent to dlv core <exe> <corefile> command.
Dependencies
To achieve this the following additional changes were made:
Implement the onStepBackRequest and onReverseContinueRequest methods on service/dap
Adapt onLaunchRequest with the requried validations and logic for these new modes
Use CapabilitiesEvent responses to enable the StepBack controls on the supported scenarios (see dicussion here)
Add the corresponding launch.json support on vs code:
Support for replay and core modes golang/vscode-go#1268
* service/dap: send continued event before step response
Send the continued event before the step response to make sure that there is no time where the client believes that only a single thread is running.
Updates golang/vscode-go#1617
* move to helper
* service/dap: send terminated event when disconnecting
If the program terminates while disconnecting, either because it
was killed or otherwise, send a terminated event.
The slice `out.List` is created with a length of 0 but a capacity of
`len(imgs)`. This causes the line below to panic as we try to index into
the `out.List` slice instead of append to it. This patch resolves the
issue by appending instead of indexing into the slice.
Co-authored-by: Derek Parker <deparker@redhat.com>
* service/dap: add panic and throw text to stopped event
We can add more information to the stopped events on errors using
the `Text` field in the stopped event. We already use this to display
the runtime errors. Adding this information to the stopped reason will
also help to show the user additional info when a stopped event is not
associated with a particular goroutine.
* proc: support new Go 1.17 panic/defer mechanism
Go 1.17 will create wrappers for deferred calls that take arguments.
Change defer reading code so that wrappers are automatically unwrapped.
Also the deferred function is called directly by runtime.gopanic, without going through runtime.callN which means that sometimes when a panic happens the stack is either:
0. deferred function call
1. deferred call wrapper
2. runtime.gopanic
or:
0. deferred function call
1. runtime.gopanic
instead of always being:
0. deferred function call
1. runtime.callN
2. runtime.gopanic
the isPanicCall check is changed accordingly.
* test: miscellaneous minor test fixes for Go 1.17
* proc: resolve inlined calls when stepping out of runtime.breakpoint
Calls to runtime.Breakpoint are inlined in Go 1.17 when inlining is
enabled, resolve inlined calls in stepInstructionOut.
* proc: add support for debugCallV2 with regabi
This change adds support for the new debug call protocol which had to
change for the new register ABI introduced in Go 1.17.
Summary of changes:
- Abstracts over the debug call version depending on the Go version
found in the binary.
- Uses R12 instead of RAX as the debug protocol register when the binary
is from Go 1.17 or later.
- Creates a variable directly from the DWARF entry for function
arguments to support passing arguments however the ABI expects.
- Computes a very conservative stack frame size for the call when
injecting a call into a Go process whose version is >=1.17.
Co-authored-by: Michael Anthony Knyszek <mknyszek@google.com>
Co-authored-by: Alessandro Arzilli <alessandro.arzilli@gmail.com>
* TeamCity: enable tests on go-tip
* goversion: version compatibility bump
* TeamCity: fix go-tip builds on macOS/arm64
Co-authored-by: Michael Anthony Knyszek <mknyszek@google.com>
The code previously expected the server to close when receiving
a message that it could not decode. However, there may be changes to
the spec that make new requests that we have not handled yet. In
that case, it would be preferable to return an error and continue handling
incoming requests.
We told clients that further loading of variables can be done by
specifying a type cast using the address of a variable that we
returned.
This does not work for registerized variables (or, in general,
variables that have a complex location expression) because we don't
give them unique addresses and we throw away the compositeMemory object
we made to read them.
This commit changes proc so that:
1. variables with location expression divided in pieces do get a unique
memory address
2. the compositeMemory object is saved somewhere
3. when an integer is cast back into a pointer type we look through our
saved compositeMemory objects to see if there is one that covers the
specified address and use it.
The unique memory addresses we generate have the MSB set to 1, as
specified by the Intel 86x64 manual addresses in this form are reserved
for kernel memory (which we can not read anyway) so we are guaranteed
to never generate a fake memory address that overlaps a real memory
address of the application.
The unfortunate side effect of this is that it will break clients that
do not deserialize the address to a 64bit integer. This practice is
contrary to how we defined our types and contrary to the specification
of the JSON format, as of json.org, however it is also fairly common,
due to javascript itself having only 53bit integers.
We could come up with a new mechanism but then even more old clients
would have to be changed.
Adds filtering and grouping to the goroutines command.
The current implementation of the goroutines command is modeled after
the threads command of gdb. It works well for programs that have up to
a couple dozen goroutines but becomes unusable quickly after that.
This commit adds the ability to filter and group goroutines by several
different properties, allowing a better debugging experience on
programs that have hundreds or thousands of goroutines.
The existing documentation was a little light on details. This patch
gives more insight into how the argument to this function is used and
interpreted.
* service/rpc2,service/debugger: more doc updates
Combine debugger.CreateBreakpoint documentation with the documentation
that already existed for the rpc2 server CreateBreakpoint method.
Also adds more contextual information for both the server and client
with links to debugger.CreateBreakpoint documentation.
We can get the throw reason by looking at the argument "s" in runtime.throw. This is not currently working in Go 1.16 or Go 1.17 (see golang/go#46425), but does work in Go 1.15 and Go 1.14
Ensure that any command executed after the process we are trying to
debug prints a correct and consistent exit status.
Previously the exit code was being lost after the first time we printed
that a process has exited. Additionally, certain commands would print
the PID of the process and other would not. This change makes everything
more correct and consistent.
Commit 30cdedae6910f5e9af6739845bacfd5b8778e745 introduced a dependency
from service/dap to pkg/terminal to call a stack printing function,
it's weird to have code that implements the DAP protocol depend on the
code for the JSON-RPC client.
Move PrintStack to a different package that can be called by both.
On hovers, including the full value for complex types is unnecessary, since the user will likely need to expand the children to inspect the values. Additionally, this can really slow down getting the hover values. This change will allow truncating the value in hover if the variable has a variables reference.
Updates golang/vscode-go#1435
Apply a presentation hint to the internal runtime stack frames, so that these can be deemphasized in the UI. This should allow
users to more easily inspect their own code, and will keep the option to view those frames if they choose to.
If the client supports paging, we allow them to fetch array and slice items in chunks that we assume will be of a reasonable size. For example, VS Code requests indexed variables in chunks of 100.
Fixesgolang/vscode-go#1518
- add 'clipboard' capability
- apply a larger string limit for 'hover' and 'clipboard' context
- truncate the string representation of compound (or pointer of compound)
type variable
If the base address isn't set then indexing and slicing will not work.
Large floating point registers already had the base set but small
general purpose registers did not.
* pkg/proc: implement support for hit count breakpoints
* update comment
* udpate hitcount comment
* update HitCond description
* add test for hit condition error
* respond to review
* service/dap: add support for hit count breakpoints
* use amendbps to preserve hit counts
* update test health doc
* fix failing test
* simplify hit conditions
* REmove RequestString, use name instead
* update backend_test_health.md
* document hit count cond
* fix tests
If the output binary name does not end with .exe, it can't run on Windows
in noDebug mode. If user-provided output name doesn't have file extension
name (.exe), append it.
Fixesgolang/vscode-go#1473
Adds DWARF register number and support for AVX-512 registers.
Changes proc/gdbserial so that the 'g' and 'G' commands are never used
with debugserver since they seem to corrupt the thread state when used
on AVX-512 capable hardware.
Also changes TestClientServer_FpRegisters to be simpler and more
resilient to changes to the Go runtime.
Fixes#2479
