Co-authored-by: NPolina Sokolova <polinasok@users.noreply.github.com>

Since the install instructions are more or less the same on all four
operating systems, remove individual install instruction links from
readme.

* service/dap: add test verifying handling of relative program path

* Add exec test, log build dir and document in --help
Co-authored-by: NPolina Sokolova <polinasok@users.noreply.github.com>

* terminal,service: add way to see internal breakpoints

Now that Delve has internal breakpoints that survive for long periods
of time it will be useful to have an option to display them.

* proc,terminal,service: support stack watchpoints

Adds support for watchpoints on stack allocated variables.

When a stack variable is watched, in addition to the normal watchpoint
some support breakpoints are created:

- one breakpoint inside runtime.copystack, used to adjust the address
  of the watchpoint when the stack is resized
- one or more breakpoints used to detect when the stack variable goes
  out of scope, those are similar to the breakpoints set by StepOut.

Implements #279

Before this change when you typed `help` at the Delve prompt you would
only see the following:

```
examinemem (alias: x)  Examine memory:
```

Now with this patch the output is more descriptive:

```
examinemem (alias: x)  Examine raw memory at the given address.
```

* cmd/dlv: dlv version --verbose

That prints out runtime/debug.BuildInfo read from the dlv binary.
Users can retrieve the same info using `go version -m <path_to_dlv>`
but I think it is convenient to have.

If dlv was built from cloned delve repo:

```
$ ./dlv version -v
Delve Debugger
Version: 1.7.0
Build: $Id: e353a65161e6ed74952b96bbb62ebfc56090832b $
Build Details: go1.16.5
 mod    github.com/go-delve/delve       (devel)
 dep    github.com/cosiner/argv v0.1.0  h1:BVDiEL32lwHukgJKP87btEPenzrrHUjajs/8yzaqcXg=
...
```

If dlv was built with `go install github.com/go-delve/delve@latest`
with go1.16+, or
`GO111MODULE=on go get github.com/go-delve/delve@latest`
from a clean main module:

```
$ ./dlv version -v
Delve Debugger
Version: 1.7.0
Build: $Id: e353a65161e6ed74952b96bbb62ebfc56090832b $
Build Details: go1.16.5
 mod    github.com/go-delve/delve       v1.7.0
 dep    github.com/cosiner/argv v0.1.0  h1:BVDiEL32lwHukgJKP87btEPenzrrHUjajs/8yzaqcXg=
...
```

* remove an accidentally added bogus test

This removes indirect dependencies from go.mod, and
includes the fix for the missing -help flag info.

The latest cobra release is v1.2.1. Given that there were
minor security-related dependency cleanup during v1.2 release,
I was tempted to pick up the latest version, but that caused
dependency updates in golang.org/x/sys and golang.org/x/tools
which may be too recent (golang.org/x/* follow the go's release
support policy, so recent versions may not be compatible with
go versions beyond go's official version support policy).

Verified that dlv still builds with go1.12.x.
(go1.12 is the oldest version of go that can build the latest delve already).

$ go get -d github.com/spf13/cobra@v1.1.3
$ go mod tidy
$ go mod vendor
$ go run _scripts/gen-usage-docs.go

* terminal: improve 'on' command

Adds the ability to edit the list of commands executed after stopping
on a breakpoint, as well as converting a breakpoint into a tracepoint
and vice versa.

Prior to this it was possible to add commands to a breakpoint but
removing commands or changing a breakpoint into a tracepoint, or vice
versa, could only be done by removing and recreating the breakpoint.

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

Co-authored-by: NPolina Sokolova <polinasok@users.noreply.github.com>

ConvertEvalScope() attempts to find the scope for the specified
goroutine id and frame index. If the goroutine that is found is nil,
then it falls back to the threads stack trace to find the scope.
This fix makes sure that the frame id is taken into account for
thread strack traces as well.

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.

Co-authored-by: NPolina Sokolova <polinasok@users.noreply.github.com>

Adds a -hitcount argument to condition that sets a hitcount condition
on breakpoints.

Change gen-backend_test_health.go so that it only prints the number of
tests skipped and not the total or the percentage.
As it is it causes too many merge conflicts.

Adds API calls and terminal commands to set watchpoints.

A RequestManualStop received while the target program is stopped can
induce a crash when the target is restarted.
This is caused by the phantom breakpoint detection that was introduced
in PR #2179 / commit e69d536e.
Instead of always interpreting an unexplained SIGTRAP as a phantom
breakpoint memorize all possible unreported breakpoint hits and only
act on it when the thread hasn't moved from one.

Also clarifies the behavior of the halt command when it is received
while the target is stopped or in the process of stopping.

Adds the low-level support for watchpoints (aka data breakpoints) to
the native linux/amd64 backend.

Does not add user interface or functioning support for watchpoints
on stack variables.

Updates #279

Changes the expression evaluation code so that register names, when not
shadowed by local or global variables, will evaluate to the current
value of the corresponding CPU register.

This allows a greater flexibility with displaying CPU registers than is
possible with using the ListRegisters API call. Also it allows
debuggers users to view register values even if the frontend they are
using does not implement a register view.

Add documentation on how to pass arguments to the program generated by
`dlv test`.

Fixes #2458

The documentation mentions flags that do not exist. Replace them with
the existing, --log-dest flag.

* examinememory: evaluate addr as expression

This makes it easy to read memory locations at an offset of a known
address, e.g.:

x 0xc000046800 + 32

* use feedback from @aarzilli

- expression mode is now enabled via -x flag
- support "-x var", "-x &var" in addition to "-x <addr expr>"
- some refactoring

* add test cases

* deal with double spaces

* update docs

* add new failing test

* fix docs

* simplify implementation, update test & docs

* Fix docs

Delete tests for old versions of Go that are no longer run, remove skip
from tests that seemingly work.

Some users seem to need to do this in order to use a debugger.

Changes print so a format argument can be specified by using '%' as
prefix. For example:

    print %x d

will print variable 'd' in hexadecimal. The interpretarion of the
format argument is the same as that of fmt's package.

Fixes #1038
Fixes #1800
Fixes #2159

* Adds toggle command

Also adds two rpc2 tests for testing the new functionality

* Removes Debuggers' ToggleBreakpoint method

rpc2's ToggleBreakpoint now calls AmendBreakpoint
Refactors the ClearBreakpoint to avoid a lock.

* fix spelling error

* Revert "fix spelling error"

This reverts commit 08058c9efbcee5d86ef429be5bd66f8307fb02d8.

* update doc source and doc/fix spelling error

This change allows specifying an optional linespec after the 'continue'
command which sets a temporary breakpoint.

Fixes #2373

This adds a workaround for the bug described at:

https://github.com/golang/go/issues/25841

Because dsymutil running on PIE does not adjust the address of
debug_frame entries (but adjusts debug_info entries) we try to do the
adjustment ourselves.

Updates #2346

- remove github workflow for testing macOS/amd64 that is now covered by
  TeamCity
- fix DeepSource glob patterns to actually match what they are intended
  to match (did the interpretation change?)
- disable some cgo tests on darwin/arm64

Delve represents registerized variables (fully or partially) using
compositeMemory, implementing proc.(*compositeMemory).WriteMemory is
necessary to make SetVariable and function calls work when Go will
switch to using the register calling convention in 1.17.

This commit also makes some refactoring by moving the code that
converts between register numbers and register names out of pkg/proc
into a different package.

* TeamCity: add linux/arm64/tip configuration

So that it can be tested when we make the next-version-support-branch.

* tests: disable failing cgo tests on arm64

Remove OS specific install instructions that all repeat the same thing.
Since `go get ...` is being deprecated (to install executables)
recommend an install procedure that works on all supported versions of
go (`git clone && go install`) but also mention the new `go install`
mode in 1.16.