Step into and step out are required by the UI for DAP. We don't have a
way to implement these in a logical manner but they need to exist. We'll
discuss in further iterations how these might differ from next and
continue, but for now, we just need some implementation for the UI.
Signed-off-by: Jonathan A. Sternberg <jonathan.sternberg@docker.com>
Implement variable references to inspect the state of a stack frame.
Variable reference ids are composed of two sections. A thread mask that
is the first 8 bytes and the remainder is an increasing number that gets
reset each time a thread is resumed. This allows the adapter to know
which thread to delegate the variables request to and allows the
variable references to still remain confined to each thread. An int32 is
used for this because variable references need to be in the range of
(0, 2^32).
At the moment, only the platform variables and some of the exec
operations for an operation. These are labeled as "arguments" to the
stack frame.
Signed-off-by: Jonathan A. Sternberg <jonathan.sternberg@docker.com>
It is now possible to send next and continue as separate signals. When
executing a build, the debug adapter will divide the LLB graph into
regions. Each region corresponds to an uninterrupted chain of
instructions. It will also record which regions depend on which other
ones.
This determines the execution order and it also determines what the
stack traces look like.
When continue is used, we will attempt to evaluate the last leaf node
(the head). If we push next, we will determine which digest would be the
next one to be processed.
In the future, this will be used to also support breakpoints.
Signed-off-by: Jonathan A. Sternberg <jonathan.sternberg@docker.com>
Adds a simple implementation of the debug adapter that supports the very
basics of a debug adapter.
It supports the launch request, the configuration done request, the
creation of threads, stopping, resuming, and disconnecting from server.
It does not support custom breakpoints, stack traces, or variable
inspection yet. These are planned to be added in the future.
Signed-off-by: Jonathan A. Sternberg <jonathan.sternberg@docker.com>
