1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454
/*
* Copyright 2019 The Starlark in Rust Authors.
* Copyright (c) Facebook, Inc. and its affiliates.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
//! Provides utilities useful for implementation of the debug adapter protocol (DAP, see
//! <https://microsoft.github.io/debug-adapter-protocol/>), primarily the DapAdapter/DapAdapterEvalHook
//! that provide for debugging a starlark Evaluation.
use std::fmt::Debug;
use std::fmt::Display;
use debugserver_types::*;
use dupe::Dupe;
use crate::codemap::FileSpan;
use crate::eval::Evaluator;
use crate::syntax::AstModule;
use crate::values::dict::DictRef;
use crate::values::layout::heap::heap_type::Heap;
use crate::values::layout::value::Value;
mod implementation;
mod tests;
/// The DapAdapterClient is implemented by the user and provides functionality required by the DapAdapter.
pub trait DapAdapterClient: Debug + Send + Sync + 'static {
/// Indicates that the evaluation stopped at a breakpoint.
fn event_stopped(&self);
}
/// Information about the variables scopes
pub struct ScopesInfo {
/// Number of local variables.
pub num_locals: usize,
}
/// Information about a "structural variable" inspected by a debugger
/// this currently has DAP-like semantic meaning that every complex object returned
/// by debugger from the stack or from the heap can be broken down into "variables"
/// this is how structured data is managed by the debugger.
/// Something similar to LLDB's SBValue
pub struct Variable {
/// Name of the variable.
pub name: PathSegment,
/// The value as a String.
pub value: String,
/// The variables type.
pub type_: String,
/// Indicates whether there are children available for a given variable.
pub has_children: bool,
}
/// Represents the scope of a variable.
#[derive(Clone, Debug)]
pub enum Scope {
/// A local variable's scope, identified by its name.
Local(String),
/// A scope determined by a particular expression.
#[allow(dead_code)]
Expr(String),
}
/// Represents a variable's "access path" for a local variable or watch expression.
///
/// # Examples
///
/// - For path `var1.field1[0]`, the scope is `Local("var1")` and the access path is `["field1", 0]`.
/// - For path `someObject.method().something`, the scope is `Expr("someObject.method().something")`. The access path
/// includes segments inside the evaluated result of `someObject.method().something` if it returns a complex object.
#[derive(Clone, Debug)]
pub struct VariablePath {
scope: Scope,
access_path: Vec<PathSegment>,
}
impl VariablePath {
/// creates new instance of VariablePath from a given expression
pub fn new_expression(expr: impl Into<String>) -> VariablePath {
VariablePath {
scope: Scope::Expr(expr.into()),
access_path: vec![],
}
}
/// creates new instance of VariablePath from a given local variable
pub fn new_local(scope: impl Into<String>) -> VariablePath {
VariablePath {
scope: Scope::Local(scope.into()),
access_path: vec![],
}
}
/// creates a child segment of given access path
pub fn make_child(&self, path: PathSegment) -> VariablePath {
// TODO(vmakaev): figure out if need to optimize memory usage and build persistent data structure
let mut access_path = self.access_path.clone();
access_path.push(path);
Self {
scope: self.scope.clone(),
access_path,
}
}
}
/// Represents a segment in an access expression.
///
/// For the given expression `name.field1.array\[0\]`, the segments are "field1", "array", and "0".
#[derive(Clone, Debug)]
pub enum PathSegment {
/// Represents a path segment that accesses array-like types (i.e., types indexable by numbers).
Index(i32),
/// Represents a path segment that accesses object-like types (i.e., types keyed by strings).
Attr(String),
/// Represents a path segment that accesses dict items by key.
Key(String),
}
impl Display for PathSegment {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
match self {
PathSegment::Index(x) => write!(f, "{}", x),
PathSegment::Attr(x) => f.write_str(x),
PathSegment::Key(x) => write!(f, "\"{}\"", x),
}
}
}
impl PathSegment {
fn get<'v>(&self, v: &Value<'v>, heap: &'v Heap) -> crate::Result<Value<'v>> {
match self {
PathSegment::Index(i) => v.at(heap.alloc(*i), heap).map_err(Into::into),
PathSegment::Attr(key) => v.get_attr_error(key.as_str(), heap),
PathSegment::Key(i) => v.at(heap.alloc(i.to_owned()), heap).map_err(Into::into),
}
}
}
impl Variable {
/// Helper to convert to the DAP Variable type.
pub fn to_dap(self) -> debugserver_types::Variable {
debugserver_types::Variable {
name: self.name.to_string(),
value: self.value,
type_: Some(self.type_),
evaluate_name: None,
indexed_variables: None,
named_variables: None,
presentation_hint: None,
variables_reference: 0,
}
}
fn tuple_value_as_str<'v>(v: Value<'v>) -> String {
match v.length() {
Ok(size) if size > 0 => format!("<tuple, size={}>", size),
_ => "()".to_owned(),
}
}
fn list_value_as_str<'v>(v: Value<'v>) -> String {
match v.length() {
Ok(size) if size > 0 => format!("<list, size={}>", size),
_ => "[]".to_owned(),
}
}
fn dict_value_as_str<'v>(v: Value<'v>) -> String {
match v.length() {
Ok(size) if size > 0 => format!("<dict, size={}>", size),
_ => "{}".to_owned(),
}
}
fn struct_like_value_as_str<'v>(v: Value<'v>) -> String {
let attrs = v.dir_attr();
format!("<type:{}, size={}>", v.get_type(), attrs.len())
}
pub(crate) fn truncate_string(mut str_value: String, mut max_len: usize) -> String {
if str_value.len() > max_len {
// Find a valid UTF-8 cut-off point that's within our max length
while max_len > 0 && !str_value.is_char_boundary(max_len) {
max_len -= 1;
}
if max_len > 0 {
str_value.truncate(max_len);
str_value.push_str("...(truncated)");
}
}
str_value
}
pub(crate) fn value_as_str<'v>(v: &Value<'v>) -> String {
if Self::has_children(v) {
match v.get_type() {
"list" => Self::list_value_as_str(*v),
"tuple" => Self::tuple_value_as_str(*v),
"dict" => Self::dict_value_as_str(*v),
_ => Self::struct_like_value_as_str(*v),
}
} else {
match v.get_type() {
"function" => "<function>".to_owned(),
_ => {
const MAX_STR_LEN: usize = 10000;
Self::truncate_string(v.to_str(), MAX_STR_LEN)
}
}
}
}
/// creates a new instance of Variable from a given starlark value
pub fn from_value<'v>(name: PathSegment, v: Value<'v>) -> Self {
Self {
name,
value: Self::value_as_str(&v),
type_: v.get_type().to_owned(),
has_children: Self::has_children(&v),
}
}
pub(crate) fn has_children<'v>(v: &Value<'v>) -> bool {
match v.get_type() {
"function" | "never" | "NoneType" | "bool" | "int" | "float" | "string" => false,
"list" | "tuple" | "dict" => match v.length() {
Ok(length) => length > 0,
_ => false,
},
_ => true,
}
}
}
/// The kind of debugger step, used for next/stepin/stepout requests.
#[derive(Debug, Clone, Dupe, Copy)]
pub enum StepKind {
/// Step "into" the statement. This is generally used on a function call to stop in the
/// function call. In practice, this will stop on the next statement.
Into,
/// Step "over" the statement. This will stop on the next statement in the current function
/// after the current one (so will step "over" a function call).
Over,
/// Step "out" of the current function. This will stop on the next statement after this
/// function returns.
Out,
}
/// Information about variables in scope.
pub struct VariablesInfo {
/// Local variables.
pub locals: Vec<Variable>,
}
/// Information about variable child "sub-values"
#[derive(Default)]
pub struct InspectVariableInfo {
/// Child variables.
pub sub_values: Vec<Variable>,
}
/// Information about expression evaluation result
pub struct EvaluateExprInfo {
/// The value as a String.
pub result: String,
/// The variables type.
pub type_: String,
/// Indicates whether there are children available for a given variable.
pub has_children: bool,
}
impl InspectVariableInfo {
fn try_from_dict<'v>(value_dict: DictRef<'v>) -> crate::Result<Self> {
let key_segments = value_dict
.iter()
.map(|(key, value)| (PathSegment::Key(key.to_str()), value))
.collect::<Vec<_>>();
Ok(Self {
sub_values: key_segments
.into_iter()
.map(|(path_segment, value)| Variable::from_value(path_segment, value))
.collect::<Vec<_>>(),
})
}
fn try_from_struct_like<'v>(v: Value<'v>, heap: &'v Heap) -> crate::Result<Self> {
Ok(Self {
sub_values: v
.dir_attr()
.into_iter()
.map(|child_name| {
let child_value = v.get_attr_error(&child_name, heap)?;
let segment = PathSegment::Attr(child_name);
Ok(Variable::from_value(segment, child_value))
})
.collect::<crate::Result<Vec<_>>>()?,
})
}
fn try_from_array_like<'v>(v: Value<'v>, heap: &'v Heap) -> crate::Result<Self> {
let len = v.length()?;
Ok(Self {
sub_values: (0..len)
.map(|i| {
let index = heap.alloc(i);
v.at(index, heap)
.map(|v| Variable::from_value(PathSegment::Index(i), v))
})
.collect::<crate::Result<Vec<_>>>()?,
})
}
/// Trying to create InspectVariableInfo from a given starlark value
pub fn try_from_value<'v>(v: Value<'v>, heap: &'v Heap) -> crate::Result<Self> {
match v.get_type() {
"dict" => Self::try_from_dict(
DictRef::from_value(v).ok_or(anyhow::Error::msg("not a dictionary"))?,
),
"struct" => Self::try_from_struct_like(v, heap),
"list" | "tuple" => Self::try_from_array_like(v, heap),
"bool" | "int" | "float" | "string" => Ok(Default::default()),
"function" | "never" | "NoneType" => Ok(Default::default()),
// this branch will catch Ty::basic(name)
_ => Self::try_from_struct_like(v, heap),
}
}
}
impl EvaluateExprInfo {
/// Creating EvaluateExprInfo from a given starlark value
pub fn from_value(v: &Value) -> Self {
Self {
result: Variable::value_as_str(v),
type_: v.get_type().to_owned(),
has_children: Variable::has_children(v),
}
}
}
/// The DapAdapter accepts DAP requests and updates the hooks in the running evaluator.
pub trait DapAdapter: Debug + Send + 'static {
/// Sets multiple breakpoints for a file (and clears existing ones).
///
/// See <https://microsoft.github.io/debug-adapter-protocol/specification#Requests_SetBreakpoints>
fn set_breakpoints(
&self,
source: &str,
breakpoints: &ResolvedBreakpoints,
) -> anyhow::Result<()>;
/// Gets the top stack frame, may be None if entered from native.
fn top_frame(&self) -> anyhow::Result<Option<StackFrame>>;
/// Gets a stacktrace from the current execution state.
///
/// See <https://microsoft.github.io/debug-adapter-protocol/specification#Requests_StackTrace>
fn stack_trace(&self, args: StackTraceArguments) -> anyhow::Result<StackTraceResponseBody>;
/// Gets the variables scope for a frame.
///
/// See <https://microsoft.github.io/debug-adapter-protocol/specification#Requests_Scopes>
fn scopes(&self) -> anyhow::Result<ScopesInfo>;
/// Gets variables for the current scope
///
/// See <https://microsoft.github.io/debug-adapter-protocol/specification#Requests_Variables>
fn variables(&self) -> anyhow::Result<VariablesInfo>;
/// Gets all child variables for the given access path
///
/// See <https://microsoft.github.io/debug-adapter-protocol/specification#Requests_Variables>
fn inspect_variable(&self, path: VariablePath) -> anyhow::Result<InspectVariableInfo>;
/// Resumes execution.
///
/// See <https://microsoft.github.io/debug-adapter-protocol/specification#Requests_Continue>
fn continue_(&self) -> anyhow::Result<()>;
/// Continues execution until some condition.
///
/// See <https://microsoft.github.io/debug-adapter-protocol/specification#Requests_Next>
/// <https://microsoft.github.io/debug-adapter-protocol/specification#Requests_StepIn>
/// <https://microsoft.github.io/debug-adapter-protocol/specification#Requests_StepOut>
fn step(&self, kind: StepKind) -> anyhow::Result<()>;
/// Evaluates in expression in the context of the top-most frame.
///
/// See <https://microsoft.github.io/debug-adapter-protocol/specification#Requests_Evaluate>
fn evaluate(&self, expr: &str) -> anyhow::Result<EvaluateExprInfo>;
}
#[derive(Debug, Clone, Hash, Eq, PartialEq)]
pub(crate) struct Breakpoint {
span: FileSpan,
condition: Option<String>,
}
/// Breakpoints resolved to their spans.
#[derive(Debug)]
pub struct ResolvedBreakpoints(Vec<Option<Breakpoint>>);
impl ResolvedBreakpoints {
/// Converts resolved breakpoints to a SetBreakpointsResponseBody. The breakpoints should've been resolved from the corresponding SetBreakpointsRequest.
pub fn to_response(&self) -> SetBreakpointsResponseBody {
implementation::resolved_breakpoints_to_dap(self)
}
}
/// Resolves the breakpoints to their FileSpan if possible.
pub fn resolve_breakpoints(
args: &SetBreakpointsArguments,
ast: &AstModule,
) -> anyhow::Result<ResolvedBreakpoints> {
implementation::resolve_breakpoints(args, ast)
}
/// This is sort of the evaluation side of the DapAdapter. It's expected that these are on different threads
/// (the starlark evaluation is single-threaded, so certainly the DapAdapter itself doesn't do interesting
/// things there).
pub trait DapAdapterEvalHook: Debug + Send + 'static {
/// Hooks the evaluator for this DapAdapter.
fn add_dap_hooks<'v, 'a>(self: Box<Self>, eval: &mut Evaluator<'v, 'a>);
}
/// The DAP capabilities that the adapter supports.
pub fn dap_capabilities() -> Capabilities {
Capabilities {
supports_configuration_done_request: Some(true),
supports_evaluate_for_hovers: Some(true),
supports_set_variable: Some(true),
supports_step_in_targets_request: Some(true),
supports_conditional_breakpoints: Some(true),
..Capabilities::default()
}
}
/// Creates a DapAdapter and corresponding DapAdapterEvalHook.
pub fn prepare_dap_adapter(
client: Box<dyn DapAdapterClient>,
) -> (impl DapAdapter, impl DapAdapterEvalHook) {
implementation::prepare_dap_adapter(client)
}