timemachine: interactive debugger

go.mod

@@ -3,6 +3,7 @@ module github.com/stealthrocket/timecraft
 go 1.20
 
 require (
+ github.com/fatih/color v1.15.0
  github.com/google/flatbuffers v23.5.26+incompatible
  github.com/google/go-cmp v0.5.9
  github.com/google/pprof v0.0.0-20230510103437-eeec1cb781c3
@@ -16,4 +17,8 @@ require (
  gopkg.in/yaml.v3 v3.0.1
 )
 
-require golang.org/x/sys v0.8.0 // indirect
+require (
+ github.com/mattn/go-colorable v0.1.13 // indirect
+ github.com/mattn/go-isatty v0.0.19 // indirect
+ golang.org/x/sys v0.8.0 // indirect
+)

go.sum

@@ -1,3 +1,5 @@
+github.com/fatih/color v1.15.0 h1:kOqh6YHBtK8aywxGerMG2Eq3H6Qgoqeo13Bk2Mv/nBs=
+github.com/fatih/color v1.15.0/go.mod h1:0h5ZqXfHYED7Bhv2ZJamyIOUej9KtShiJESRwBDUSsw=
 github.com/google/flatbuffers v23.5.26+incompatible h1:M9dgRyhJemaM4Sw8+66GHBu8ioaQmyPLg1b8VwK5WJg=
 github.com/google/flatbuffers v23.5.26+incompatible/go.mod h1:1AeVuKshWv4vARoZatz6mlQ0JxURH0Kv5+zNeJKJCa8=
 github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
@@ -8,6 +10,11 @@ github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
 github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/klauspost/compress v1.16.5 h1:IFV2oUNUzZaz+XyusxpLzpzS8Pt5rh0Z16For/djlyI=
 github.com/klauspost/compress v1.16.5/go.mod h1:ntbaceVETuRiXiv4DpjP66DpAtAGkEQskQzEyD//IeE=
+github.com/mattn/go-colorable v0.1.13 h1:fFA4WZxdEF4tXPZVKMLwD8oUnCTTo08duU7wxecdEvA=
+github.com/mattn/go-colorable v0.1.13/go.mod h1:7S9/ev0klgBDR4GtXTXX8a3vIGJpMovkB8vQcUbaXHg=
+github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
+github.com/mattn/go-isatty v0.0.19 h1:JITubQf0MOLdlGRuRq+jtsDlekdYPia9ZFsB8h/APPA=
+github.com/mattn/go-isatty v0.0.19/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
 github.com/stealthrocket/wasi-go v0.3.0 h1:+L+DfnHkBmOkUmCbsyO9j1KPqsAFu426jD3HH/7BABc=
 github.com/stealthrocket/wasi-go v0.3.0/go.mod h1:LBhZHvAroNNQTejkVTMJZ01ssj3jXF+3Lkbru4cTzGQ=
 github.com/stealthrocket/wazergo v0.19.0 h1:0ZBya2fBURvV+I2hGl0vcuQ8dgoUvllxQ7aYlZSA5nI=
@@ -18,6 +25,8 @@ github.com/tetratelabs/wazero v1.1.1-0.20230522055633-256b7a4bf970 h1:X5OOeHRjoL
 github.com/tetratelabs/wazero v1.1.1-0.20230522055633-256b7a4bf970/go.mod h1:wYx2gNRg8/WihJfSDxA1TIL8H+GkfLYm+bIfbblu9VQ=
 golang.org/x/exp v0.0.0-20230522175609-2e198f4a06a1 h1:k/i9J1pBpvlfR+9QsetwPyERsqu1GIbi967PQMq3Ivc=
 golang.org/x/exp v0.0.0-20230522175609-2e198f4a06a1/go.mod h1:V1LtkGg67GoY2N1AnLN78QLrzxkLyJw7RJb1gzOOz9w=
+golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.8.0 h1:EBmGv8NaZBZTWvrbjNoL6HVt+IVy3QDQpJs7VRIw3tU=
 golang.org/x/sys v0.8.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=

internal/debug/event.go

@@ -0,0 +1,75 @@
+package debug
+
+import (
+ "github.com/stealthrocket/timecraft/internal/timemachine/wasicall"
+ "github.com/tetratelabs/wazero"
+ "github.com/tetratelabs/wazero/api"
+ "github.com/tetratelabs/wazero/experimental"
+)
+
+// Event is an event generated during execution of a WebAssembly module.
+type Event interface {
+ event()
+}
+
+// ModuleBeforeEvent is an event that's triggered before a module is executed.
+type ModuleBeforeEvent struct {
+ Module wazero.CompiledModule
+}
+
+func (*ModuleBeforeEvent) event() {}
+
+// ModuleAfterEvent is an event that's triggered after a module has been
+// executed.
+type ModuleAfterEvent struct {
+ Error any
+}
+
+func (*ModuleAfterEvent) event() {}
+
+// FunctionCallBeforeEvent is an event that's triggered before a function is
+// called in a WebAssembly module.
+type FunctionCallBeforeEvent struct {
+ Module api.Module
+ Function api.FunctionDefinition
+ Params []uint64
+ StackIterator experimental.StackIterator
+}
+
+func (*FunctionCallBeforeEvent) event() {}
+
+// FunctionCallAfterEvent is an event that's triggered after a function is
+// called in a WebAssembly module.
+type FunctionCallAfterEvent struct {
+ Module api.Module
+ Function api.FunctionDefinition
+ Results []uint64
+}
+
+func (*FunctionCallAfterEvent) event() {}
+
+// FunctionCallAbortEvent is an event that's triggered when a function call is
+// aborted in a WebAssembly module.
+type FunctionCallAbortEvent struct {
+ Module api.Module
+ Function api.FunctionDefinition
+ Error error
+}
+
+func (*FunctionCallAbortEvent) event() {}
+
+// SystemCallBeforeEvent is an event that's triggered before a WASI host
+// function is called in a WebAssembly module.
+type SystemCallBeforeEvent struct {
+ wasicall.Syscall
+}
+
+func (*SystemCallBeforeEvent) event() {}
+
+// SystemCallAfterEvent is an event that's triggered before a WASI host
+// function is called in a WebAssembly module.
+type SystemCallAfterEvent struct {
+ wasicall.Syscall
+}
+
+func (*SystemCallAfterEvent) event() {}

internal/debug/listener.go

@@ -0,0 +1,93 @@
+package debug
+
+import (
+ "context"
+
+ "github.com/stealthrocket/timecraft/internal/timemachine/wasicall"
+ "github.com/stealthrocket/wasi-go"
+ "github.com/tetratelabs/wazero/api"
+ "github.com/tetratelabs/wazero/experimental"
+)
+
+// Listener is an Event listener.
+//
+// The Listener exists to bridge the gap between wazero's low-level
+// experimental.FunctionListener and the higher-level wasi.System interface.
+// The Listener can be connected to either or both sources of events and can
+// be used to drive interactive debugging experiences. The design also allows
+// for additional types of Event to be added in future, such as events
+// triggered when doing instruction or line level stepping.
+type Listener interface {
+ // OnEvent is an Event handler.
+ //
+ // The Event and its fields must not be retained across calls.
+ OnEvent(context.Context, Event)
+}
+
+// RegisterFunctionListener registers an experimental.FunctionListener that
+// generates FunctionCallBeforeEvent and FunctionCallAfterEvent events for the provided
+// Listener.
+//
+// The listener must be registered before the WebAssembly module is compiled.
+func RegisterFunctionListener(ctx context.Context, listener Listener) context.Context {
+ return context.WithValue(ctx,
+ experimental.FunctionListenerFactoryKey{},
+ NewFunctionListenerFactory(listener),
+ )
+}
+
+// NewFunctionListenerFactory creates a experimental.FunctionListenerFactory
+// that builds an experimental.FunctionListener that generates
+// FunctionCallBeforeEvent and FunctionCallAfterEvent events for the provided
+// Listener.
+func NewFunctionListenerFactory(listener Listener) experimental.FunctionListenerFactory {
+ return &functionListenerFactory{listener}
+}
+
+type functionListenerFactory struct {
+ Listener
+}
+
+func (c *functionListenerFactory) NewFunctionListener(definition api.FunctionDefinition) experimental.FunctionListener {
+ return &functionListener{Listener: c.Listener}
+}
+
+type functionListener struct {
+ Listener
+
+ // cached events
+ before FunctionCallBeforeEvent
+ after FunctionCallAfterEvent
+ abort FunctionCallAbortEvent
+}
+
+func (l *functionListener) Before(ctx context.Context, mod api.Module, def api.FunctionDefinition, params []uint64, stackIterator experimental.StackIterator) {
+ l.before = FunctionCallBeforeEvent{mod, def, params, stackIterator}
+ l.Listener.OnEvent(ctx, &l.before)
+}
+
+func (l *functionListener) After(ctx context.Context, mod api.Module, def api.FunctionDefinition, results []uint64) {
+ l.after = FunctionCallAfterEvent{mod, def, results}
+ l.Listener.OnEvent(ctx, &l.after)
+}
+
+func (l *functionListener) Abort(ctx context.Context, mod api.Module, def api.FunctionDefinition, err error) {
+ l.abort = FunctionCallAbortEvent{mod, def, err}
+ l.Listener.OnEvent(ctx, &l.abort)
+}
+
+// WASIListener wraps a wasi.System to generate SystemCallBeforeEvent and
+// SystemCallAfterEvent events for the provided Listener.
+func WASIListener(system wasi.System, listener Listener) wasi.System {
+ var before SystemCallBeforeEvent
+ var after SystemCallAfterEvent
+ return wasicall.NewObserver(system,
+ func(ctx context.Context, syscall wasicall.Syscall) {
+ before = SystemCallBeforeEvent{syscall}
+ listener.OnEvent(ctx, &before)
+ },
+ func(ctx context.Context, syscall wasicall.Syscall) {
+ after = SystemCallAfterEvent{syscall}
+ listener.OnEvent(ctx, &after)
+ })
+}