Next sets its temporary breakpoints with the condition that they
must only activate on the current goroutine, and then calls Continue
When Continue encounters a temporary breakpoint it clears all
the breakpoint.
User visible changes: breakpoints that get hit while executing Next
are not ignored.
This commit does not implement full conditional breakpoints
functionality, the only condition that can be set is on the
goroutine id.
Fixes race conditions in Next affecting TestNextConcurrent.
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.
Instead of trying to be clever and make an 'educated guess' as to where
the flow of control may go next, simple do the more naive, yet correct,
approach of setting a breakpoint everywhere we can in the function and
seeing where we end up. On top of this we were already setting a
breakpoint at the return address and deferred functions, so that remains
the same.
This removes a lot of gnarly, hard to maintain code and takes all the
guesswork out of this command.
Fixes#281
Only use software breakpoints for now. The reasoning is because it
complicates the code without justification, and is only supported on
Linux. Eventually, once watchpoints are properly implemented we will
revive some of this code. Also, if it is ever necessary to actually set
a hw breakpoint we can revive that code as well.
All future versions of this code will include support for OSX before
being merged back in.
Support multiple file / directory tables for multiple compilation units.
- added a type DebugLines that can hold number of DebugLineInfo
- added a supporting attribute to DebugLineInfo called 'Lookup' which is to be
used to quickly lookup if file exists in FileNames slice
- added supporting methods to lookup and return corresponding DebugLineInfo
- changed the debug_line parsing behavior to read all the available tables and
push them to DebugLines
- since Process.lineInfo is now a slice, it was breaking AllPCsBetween as well
- updated that function's definition to accept a new filename parameter to be
able to extract related DebugLineInfo
- updated calls to AllPCsBetween
- fixed tests that were broken due to attribute type change in Process
- updated _fixtures/cgotest program to include stdio.h, so that it updates
.debug_line header
- added a test to check 'next' in a cgo binary
- OSX - 1.4 does not support cgo, handle that in new testcase
This patch aims to improve how Delve tracks the current goroutine,
especially in very highly parallel programs. The main spirit of this
patch is to ensure that even in situations where the goroutine we care
about is not executing (common for len(g) > len(m)) we still end up back
on that goroutine as a result of executing the 'next' command.
We accomplish this by tracking our original goroutine id, and any time a
breakpoint is hit or a threads stops, we examine the stopped threads and
see if any are executing the goroutine we care about. If not, we set
'next' breakpoint for them again and continue them. This is done so that
one of those threads can eventually pick up the goroutine we care about
and begin executing it again.
For hardware breakpoints we have to set them on every thread. It could
be the case that another thread is running. Stop it first, set the
breakpoint, then continue it.
