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

Fixes #940

Windows doesn't actually have ptrace.

Fixes #778

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

- move native backend to pkg/proc/native
- move gdbserver backend to pkg/proc/gdbserial
- move core dumps backend to pkg/proc/core

* proc: refactor BinaryInfo part of proc.Process to own type

The data structures and associated code used by proc.Process
to implement target.BinaryInfo will also be useful to support a
backend for examining core dumps, split this part of proc.Process
to a different type.

* proc: compile support for all executable formats unconditionally

So far we only compiled in support for loading the executable format
supported by the host operating system.
Once support for core files is introduced it is however useful to
support loading in all executable formats, there is no reason why it
shouldn't be possible to examine a linux coredump on windows, or
viceversa.

* proc: bugfix: do not resume threads on detach if killing

* Replace BinaryInfo interface with BinInfo() method returning proc.BinaryInfo

Detach did not work for processes we attach to via PID.

Linux: we were only detaching from the main thread, all threads are
detached independently

Windows: we must resume all threads before detaching.

macOS: still broken.

Updates #772

Fixes #732

Signed-off-by: NKoichi Shiraishi <zchee.io@gmail.com>

* service/debugger: Restore breakpoints using file:line on restart

Restoring by address can cause the breakpoint to be inserted in the
middle of an instruction if the executable file has changed.

* terminal: Warn of stale executable when printing source

Fixes #645

* proc: Add `wd` to Launch

This change adds the `wd` arg which specify working directory of the
program.

Fixes #295

* service/debugger: Add `Wd` field to debugger.Config

This change adds the `Wd` field which specify working directory of the
program launched by debugger.

Fixes #295

* service: Add `Wd` to service.Config

This change adds the `Wd` field which specify working directory of the
program debugger will launch.

Fixes #295

* cmd/dlv: Add `Wd` flag

This change adds `Wd` flag which specify working directory of the
program which launched by debugger.

Fixes #295

* only set the Linux working directory if it is set,
stub out param in darwin and windows

* set working directory for Windows
https://godoc.org/golang.org/x/sys/windows#CreateProcess
https://msdn.microsoft.com/en-us/library/windows/desktop/ms682425(v=vs.85).aspx

* Windows workingDir must be an *uint16

* attempt to chdir on darwin via @yuntan

* proc/exec_darwin.c: fix working directory for darwin

* Add tests to check if working directory works.
* Fix darwin implementation of fork/exec, which paniced if
  child fork returned.

* cmd, service: rename Wd to WorkingDir

Patch https://go-review.googlesource.com/23085 has been merged so we
can go back to using golang.org/x/debug/.

This provides a better error message when the user tries to run dlv
debug on a directory that does not contain a main package, when `dlv
exec` is used with a source file.

Additionally the architecture of the executable is checked as suggested
by @alexbrainman in #443.

Fixes #509

* tests: update to cope with go1.7 SSA compiler

* de-vendored golang.org/x/debug/dwarf

We need our own tweaked version

* dwarf/debug/dwarf: always use the entry's name attribute

Using the name attribute leads to better type names as well as fixes
inconsistencies between 1.5, 1.6 and 1.7.

* proc: Updated loadInterface to work with go1.7

go1.7 changed the internal representation of types, removing the string
field from runtime._type.
Updated loadInterface to use the new str field.

This patch modifies the `step` command to step to the next source line,
stepping into any function encountered along the way.

Fixes #360

Typedefs that resolve to slices are not recorded in DWARF as typedefs
but instead as structs in a way that there is no way to know they
are really slices using debug/dwarf.
Using golang.org/x/debug/dwarf instead this problem is solved and
as a bonus some types are printed with a nicer names: (struct string
→ string, struct []int → []int, etc)

 Fixes #356 and #293

Fixes #198.

resume loops in continueOnce moved to a OS specific resume function,
this makes the problem easier to deal with and seems to be more
appropriate to a windows port given what transpired from discussion
of Pull Request #276

Fixes #262

Breakpoints are skipped either because:
1. when multiple breakpoints are hit simultaneously only one is
processed
2. a thread hits a breakpoint while another thread is being
singlestepped over the breakpoint.

Additionally fixed a race condition between Continue and tracee
termination.

Prevents a lot of goroutines hanging around, especially when running
tests.

/proc/pid/stat needs more complex parsing

Fixes #239

Fixes a bug on OSX where, if the debugged process spawned a child, when
that process received a SIGCHLD it would cause Delve to hang.

Fixes #197