Track async causal stack traces

runtime/vm/parser.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/parser.h"
 #include "vm/flags.h"
 
 #ifndef DART_PRECOMPILED_RUNTIME
 
 #include "lib/invocation_mirror.h"
@@ skipping 3450 matching lines @@
     func.set_modifier(func_modifier);
   }
 
   OpenBlock();  // Open a nested scope for the outermost function block.
 
   Function& generated_body_closure = Function::ZoneHandle(Z);
   if (func.IsAsyncFunction()) {
     ASSERT(!func.is_generated_body());
     // The code of an async function is synthesized. Disable debugging.
     func.set_is_debuggable(false);
+    // In order to produce sane asynchronous stacks we rely on this function

[rmacnak, 2017/01/26 18:05:58]

To collect them efficiently.

[Cutch, 2017/01/31 23:45:31]

Done (here and elsewhere).

+    // not being inlined.
+    func.set_is_inlinable(!FLAG_sane_async_stacks);
     generated_body_closure = OpenAsyncFunction(func.token_pos());
   } else if (func.IsAsyncClosure()) {
     // The closure containing the body of an async function is debuggable.
     ASSERT(func.is_debuggable());
+    // In order to produce sane asynchronous stacks we rely on this function
+    // not being inlined.
+    func.set_is_inlinable(!FLAG_sane_async_stacks);
     OpenAsyncClosure();
   } else if (func.IsSyncGenerator()) {
     // The code of a sync generator is synthesized. Disable debugging.
     func.set_is_debuggable(false);
     generated_body_closure = OpenSyncGeneratorFunction(func.token_pos());
   } else if (func.IsSyncGenClosure()) {
     // The closure containing the body of a sync generator is debuggable.
     ASSERT(func.is_debuggable());
     async_temp_scope_ = current_block_->scope;
   } else if (func.IsAsyncGenerator()) {
     func.set_is_debuggable(false);
+    // In order to produce sane asynchronous stacks we rely on this function
+    // not being inlined.
+    func.set_is_inlinable(!FLAG_sane_async_stacks);
     generated_body_closure = OpenAsyncGeneratorFunction(func.token_pos());
   } else if (func.IsAsyncGenClosure()) {
     // The closure containing the body of an async* function is debuggable.
     ASSERT(func.is_debuggable());
+    // In order to produce sane asynchronous stacks we rely on this function
+    // not being inlined.
+    func.set_is_inlinable(!FLAG_sane_async_stacks);
     OpenAsyncGeneratorClosure();
   }
 
   BoolScope allow_await(&this->await_is_keyword_,
                         func.IsAsyncOrGenerator() || func.is_generated_body());
   TokenPosition end_token_pos = TokenPosition::kNoSource;
   if (CurrentToken() == Token::kLBRACE) {
     ConsumeToken();
     if (String::Handle(Z, func.name()).Equals(Symbols::EqualOperator())) {
       const Class& owner = Class::Handle(Z, func.Owner());
@@ skipping 3354 matching lines @@
   current_block_->scope->AddVariable(await_ctx_var);
 }
 
 
 void Parser::AddAsyncClosureVariables() {
   // Add to current block's scope:
   //   var :async_op;
   //   var :async_then_callback;
   //   var :async_catch_error_callback;
   //   var :async_completer;
+  //   var :async_stack_trace;
   LocalVariable* async_op_var =
       new (Z) LocalVariable(TokenPosition::kNoSource, TokenPosition::kNoSource,
                             Symbols::AsyncOperation(), Object::dynamic_type());
   current_block_->scope->AddVariable(async_op_var);
   LocalVariable* async_then_callback_var = new (Z)
       LocalVariable(TokenPosition::kNoSource, TokenPosition::kNoSource,
                     Symbols::AsyncThenCallback(), Object::dynamic_type());
   current_block_->scope->AddVariable(async_then_callback_var);
   LocalVariable* async_catch_error_callback_var = new (Z)
       LocalVariable(TokenPosition::kNoSource, TokenPosition::kNoSource,
                     Symbols::AsyncCatchErrorCallback(), Object::dynamic_type());
   current_block_->scope->AddVariable(async_catch_error_callback_var);
   LocalVariable* async_completer =
       new (Z) LocalVariable(TokenPosition::kNoSource, TokenPosition::kNoSource,
                             Symbols::AsyncCompleter(), Object::dynamic_type());
   current_block_->scope->AddVariable(async_completer);
+  LocalVariable* async_stack_trace = new (Z)
+      LocalVariable(TokenPosition::kNoSource, TokenPosition::kNoSource,
+                    Symbols::AsyncStackTraceVar(), Object::dynamic_type());
+  current_block_->scope->AddVariable(async_stack_trace);
 }
 
 
 void Parser::AddAsyncGeneratorVariables() {
   // Add to current block's scope:
   //   var :controller;
   // The :controller variable is used by the async generator closure to
   // store the StreamController object to which the yielded expressions
   // are added.
   //   var :async_op;
   //   var :async_then_callback;
   //   var :async_catch_error_callback;
+  //   var :async_stack_trace;
   // These variables are used to store the async generator closure containing
   // the body of the async* function. They are used by the await operator.
   LocalVariable* controller_var =
       new (Z) LocalVariable(TokenPosition::kNoSource, TokenPosition::kNoSource,
                             Symbols::Controller(), Object::dynamic_type());
   current_block_->scope->AddVariable(controller_var);
   LocalVariable* async_op_var =
       new (Z) LocalVariable(TokenPosition::kNoSource, TokenPosition::kNoSource,
                             Symbols::AsyncOperation(), Object::dynamic_type());
   current_block_->scope->AddVariable(async_op_var);
   LocalVariable* async_then_callback_var = new (Z)
       LocalVariable(TokenPosition::kNoSource, TokenPosition::kNoSource,
                     Symbols::AsyncThenCallback(), Object::dynamic_type());
   current_block_->scope->AddVariable(async_then_callback_var);
   LocalVariable* async_catch_error_callback_var = new (Z)
       LocalVariable(TokenPosition::kNoSource, TokenPosition::kNoSource,
                     Symbols::AsyncCatchErrorCallback(), Object::dynamic_type());
   current_block_->scope->AddVariable(async_catch_error_callback_var);
+  LocalVariable* async_stack_trace = new (Z)
+      LocalVariable(TokenPosition::kNoSource, TokenPosition::kNoSource,
+                    Symbols::AsyncStackTraceVar(), Object::dynamic_type());
+  current_block_->scope->AddVariable(async_stack_trace);
 }
 
 
 RawFunction* Parser::OpenAsyncGeneratorFunction(TokenPosition async_func_pos) {
   TRACE_PARSER("OpenAsyncGeneratorFunction");
   AddContinuationVariables();
   AddAsyncGeneratorVariables();
 
   Function& closure = Function::Handle(Z);
   bool is_new_closure = false;
@@ skipping 77 matching lines @@
   ASSERT((existing_var != NULL) && existing_var->is_captured());
   existing_var =
       closure_body->scope()->LookupVariable(Symbols::AsyncOperation(), false);
   ASSERT((existing_var != NULL) && existing_var->is_captured());
   existing_var = closure_body->scope()->LookupVariable(
       Symbols::AsyncThenCallback(), false);
   ASSERT((existing_var != NULL) && existing_var->is_captured());
   existing_var = closure_body->scope()->LookupVariable(
       Symbols::AsyncCatchErrorCallback(), false);
   ASSERT((existing_var != NULL) && existing_var->is_captured());
+  existing_var = closure_body->scope()->LookupVariable(
+      Symbols::AsyncStackTraceVar(), false);
+  ASSERT((existing_var != NULL) && existing_var->is_captured());
 
   const Library& async_lib = Library::Handle(Library::AsyncLibrary());
 
   const Class& controller_class = Class::Handle(
       Z,
       async_lib.LookupClassAllowPrivate(Symbols::_AsyncStarStreamController()));
   ASSERT(!controller_class.IsNull());
   const Function& controller_constructor = Function::ZoneHandle(
       Z, controller_class.LookupConstructorAllowPrivate(
              Symbols::_AsyncStarStreamControllerConstructor()));
 
   // :await_jump_var = -1;
   LocalVariable* jump_var =
       current_block_->scope->LookupVariable(Symbols::AwaitJumpVar(), false);
   LiteralNode* init_value = new (Z)
       LiteralNode(TokenPosition::kNoSource, Smi::ZoneHandle(Smi::New(-1)));
   current_block_->statements->Add(
       new (Z) StoreLocalNode(TokenPosition::kNoSource, jump_var, init_value));
 
+  TokenPosition token_pos = TokenPosition::kNoSource;
+
+  // Add to AST:

[rmacnak, 2017/01/26 18:05:58]

if (FLAG_sane_async_stacks)

+  //   :async_stack_trace = _asyncStackTraceHelper();
+  const Function& async_stack_trace_helper = Function::ZoneHandle(
+      Z,
+      async_lib.LookupFunctionAllowPrivate(Symbols::AsyncStackTraceHelper()));
+  ASSERT(!async_stack_trace_helper.IsNull());
+  ArgumentListNode* async_stack_trace_helper_args =
+      new (Z) ArgumentListNode(TokenPosition::kNoSource);
+  StaticCallNode* async_stack_trace_helper_call = new (Z) StaticCallNode(
+      token_pos, async_stack_trace_helper, async_stack_trace_helper_args);
+  LocalVariable* async_stack_trace_var = current_block_->scope->LookupVariable(
+      Symbols::AsyncStackTraceVar(), false);
+  StoreLocalNode* store_async_stack_trace = new (Z) StoreLocalNode(
+      token_pos, async_stack_trace_var, async_stack_trace_helper_call);
+  current_block_->statements->Add(store_async_stack_trace);
+
   // Add to AST:
   //   :async_op = <closure>;  (containing the original body)
   LocalVariable* async_op_var =
       current_block_->scope->LookupVariable(Symbols::AsyncOperation(), false);
   ClosureNode* closure_obj = new (Z) ClosureNode(
       TokenPosition::kNoSource, closure_func, NULL, closure_body->scope());
   StoreLocalNode* store_async_op = new (Z)
       StoreLocalNode(TokenPosition::kNoSource, async_op_var, closure_obj);
 
   current_block_->statements->Add(store_async_op);
@@ skipping 123 matching lines @@
   // closure body in order to mark them as captured.
   LocalVariable* existing_var =
       closure_body->scope()->LookupVariable(Symbols::AwaitJumpVar(), false);
   ASSERT((existing_var != NULL) && existing_var->is_captured());
   existing_var =
       closure_body->scope()->LookupVariable(Symbols::AwaitContextVar(), false);
   ASSERT((existing_var != NULL) && existing_var->is_captured());
   existing_var =
       closure_body->scope()->LookupVariable(Symbols::AsyncCompleter(), false);
   ASSERT((existing_var != NULL) && existing_var->is_captured());
+  existing_var = closure_body->scope()->LookupVariable(
+      Symbols::AsyncStackTraceVar(), false);
+  ASSERT((existing_var != NULL) && existing_var->is_captured());
 
   // Create and return a new future that executes a closure with the current
   // body.
 
   // No need to capture parameters or other variables, since they have already
   // been captured in the corresponding scope as the body has been parsed within
   // a nested block (contained in the async function's block).
   const Class& future = Class::ZoneHandle(Z, I->object_store()->future_class());
   ASSERT(!future.IsNull());
   const Function& constructor = Function::ZoneHandle(
@@ skipping 32 matching lines @@
   //   :async_op = <closure>;  (containing the original body)
   LocalVariable* async_op_var =
       current_block_->scope->LookupVariable(Symbols::AsyncOperation(), false);
   ClosureNode* cn =
       new (Z) ClosureNode(token_pos, closure, NULL, closure_body->scope());
   StoreLocalNode* store_async_op =
       new (Z) StoreLocalNode(token_pos, async_op_var, cn);
   current_block_->statements->Add(store_async_op);
 
   const Library& async_lib = Library::Handle(Library::AsyncLibrary());
+
+  // Add to AST:

[rmacnak, 2017/01/26 18:05:58]

if (FLAG_sane_async_stacks)

[Cutch, 2017/01/31 23:45:31]

Done.

+  //   :async_stack_trace = _asyncStackTraceHelper();
+  const Function& async_stack_trace_helper = Function::ZoneHandle(
+      Z,
+      async_lib.LookupFunctionAllowPrivate(Symbols::AsyncStackTraceHelper()));
+  ASSERT(!async_stack_trace_helper.IsNull());
+  ArgumentListNode* async_stack_trace_helper_args =
+      new (Z) ArgumentListNode(token_pos);
+  StaticCallNode* async_stack_trace_helper_call = new (Z) StaticCallNode(
+      token_pos, async_stack_trace_helper, async_stack_trace_helper_args);
+  LocalVariable* async_stack_trace_var = current_block_->scope->LookupVariable(
+      Symbols::AsyncStackTraceVar(), false);
+  StoreLocalNode* store_async_stack_trace = new (Z) StoreLocalNode(
+      token_pos, async_stack_trace_var, async_stack_trace_helper_call);
+  current_block_->statements->Add(store_async_stack_trace);
+
   // :async_then_callback = _asyncThenWrapperHelper(:async_op)
   const Function& async_then_wrapper_helper = Function::ZoneHandle(
       Z,
       async_lib.LookupFunctionAllowPrivate(Symbols::AsyncThenWrapperHelper()));
   ASSERT(!async_then_wrapper_helper.IsNull());
   ArgumentListNode* async_then_wrapper_helper_args =
       new (Z) ArgumentListNode(token_pos);
   async_then_wrapper_helper_args->Add(
       new (Z) LoadLocalNode(token_pos, async_op_var));
   StaticCallNode* then_wrapper_call = new (Z) StaticCallNode(
@@ skipping 7437 matching lines @@
     const ArgumentListNode& function_args,
     const LocalVariable* temp_for_last_arg,
     bool is_super_invocation) {
   UNREACHABLE();
   return NULL;
 }
 
 }  // namespace dart
 
 #endif  // DART_PRECOMPILED_RUNTIME