[vm,dyn_modules] Initial support for interpreter frames in debugger

Also, support reading local variables information from bytecode.

TEST=pkg/vm_service

Change-Id: Iab482316891f0e474af0011e9b1765c4e8312bc9
Cq-Include-Trybots: luci.dart.try:vm-aot-dyn-linux-debug-x64-try,vm-aot-dyn-linux-product-x64-try,vm-dyn-linux-debug-x64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/437281
Reviewed-by: Slava Egorov <[email protected]>
Commit-Queue: Alexander Markov <[email protected]>

Author: alexmarkov

pkg/dart2bytecode/bin/kernel_service.dart

@@ -29,7 +29,9 @@ Uint8List _generateBytecode(
       hierarchy: hierarchy,
       target: target,
       options: BytecodeOptions(
-          enableAsserts: enableAsserts, emitSourcePositions: true));
+          enableAsserts: enableAsserts,
+          emitSourcePositions: true,
+          emitLocalVarInfo: true));
   return byteSink.builder.takeBytes();
 }
 

runtime/vm/bytecode_reader.cc

@@ -24,6 +24,7 @@
 #include "vm/object_store.h"
 #include "vm/resolver.h"
 #include "vm/reusable_handles.h"
+#include "vm/scopes.h"
 #include "vm/stack_frame_kbc.h"
 #include "vm/symbols.h"
 #include "vm/timeline.h"
@@ -728,7 +729,13 @@ void BytecodeReaderHelper::ReadLocalVariables(const Bytecode& bytecode,
     return;
   }
 
-  reader_.ReadUInt();  // Skip local variables offset.
+  const intptr_t offset = reader_.ReadUInt();
+#if !defined(PRODUCT) && !defined(DART_PRECOMPILED_RUNTIME)
+  bytecode.set_local_variables_binary_offset(
+      bytecode_component_->GetLocalVariablesOffset() + offset);
+#else
+  USE(offset);
+#endif  // !defined(PRODUCT) && !defined(DART_PRECOMPILED_RUNTIME)
 }
 
 ArrayPtr BytecodeReaderHelper::ReadBytecodeComponent() {
@@ -2664,6 +2671,99 @@ void BytecodeReader::CollectScriptTokenPositionsFromBytecode(
   }
 }
 
+#if !defined(PRODUCT) && !defined(DART_PRECOMPILED_RUNTIME)
+
+LocalVarDescriptorsPtr BytecodeReader::ComputeLocalVarDescriptors(
+    Zone* zone,
+    const Function& function,
+    const Bytecode& bytecode) {
+  ASSERT(function.is_declared_in_bytecode());
+  ASSERT(function.HasBytecode());
+  ASSERT(!bytecode.IsNull());
+  ASSERT(function.GetBytecode() == bytecode.ptr());
+
+  LocalVarDescriptorsBuilder vars;
+
+  if (function.IsLocalFunction()) {
+    const auto& parent = Function::Handle(zone, function.parent_function());
+    ASSERT(parent.is_declared_in_bytecode() && parent.HasBytecode());
+    const auto& parent_bytecode = Bytecode::Handle(zone, parent.GetBytecode());
+    const auto& parent_vars = LocalVarDescriptors::Handle(
+        zone, parent_bytecode.GetLocalVarDescriptors());
+    for (intptr_t i = 0; i < parent_vars.Length(); ++i) {
+      UntaggedLocalVarDescriptors::VarInfo var_info;
+      parent_vars.GetInfo(i, &var_info);
+      // Include parent's context variable if variable's scope
+      // intersects with the local function range.
+      // It is not enough to check if local function is declared within the
+      // scope of variable, because in case of async functions closure has
+      // the same range as original function.
+      if (var_info.kind() == UntaggedLocalVarDescriptors::kContextVar &&
+          ((var_info.begin_pos <= function.token_pos() &&
+            function.token_pos() <= var_info.end_pos) ||
+           (function.token_pos() <= var_info.begin_pos &&
+            var_info.begin_pos <= function.end_token_pos()))) {
+        vars.Add(LocalVarDescriptorsBuilder::VarDesc{
+            &String::Handle(zone, parent_vars.GetName(i)), var_info});
+      }
+    }
+  }
+
+  if (bytecode.HasLocalVariablesInfo()) {
+    intptr_t scope_id = 0;
+    intptr_t context_level = -1;
+    BytecodeLocalVariablesIterator local_vars(zone, bytecode);
+    while (local_vars.MoveNext()) {
+      switch (local_vars.Kind()) {
+        case BytecodeLocalVariablesIterator::kScope: {
+          ++scope_id;
+          context_level = local_vars.ContextLevel();
+        } break;
+        case BytecodeLocalVariablesIterator::kVariableDeclaration: {
+          LocalVarDescriptorsBuilder::VarDesc desc;
+          desc.name = &String::Handle(zone, local_vars.Name());
+          if (local_vars.IsCaptured()) {
+            desc.info.set_kind(UntaggedLocalVarDescriptors::kContextVar);
+            desc.info.scope_id = context_level;
+            desc.info.set_index(local_vars.Index());
+          } else {
+            desc.info.set_kind(UntaggedLocalVarDescriptors::kStackVar);
+            desc.info.scope_id = scope_id;
+            if (local_vars.Index() < 0) {
+              // Parameter
+              ASSERT(local_vars.Index() < -kKBCParamEndSlotFromFp);
+              desc.info.set_index(-local_vars.Index() - kKBCParamEndSlotFromFp);
+            } else {
+              desc.info.set_index(-local_vars.Index());
+            }
+          }
+          desc.info.declaration_pos = local_vars.DeclarationTokenPos();
+          desc.info.begin_pos = local_vars.StartTokenPos();
+          desc.info.end_pos = local_vars.EndTokenPos();
+          vars.Add(desc);
+        } break;
+        case BytecodeLocalVariablesIterator::kContextVariable: {
+          ASSERT(local_vars.Index() >= 0);
+          const intptr_t context_variable_index = -local_vars.Index();
+          LocalVarDescriptorsBuilder::VarDesc desc;
+          desc.name = &Symbols::CurrentContextVar();
+          desc.info.set_kind(UntaggedLocalVarDescriptors::kSavedCurrentContext);
+          desc.info.scope_id = 0;
+          desc.info.declaration_pos = TokenPosition::kMinSource;
+          desc.info.begin_pos = TokenPosition::kMinSource;
+          desc.info.end_pos = TokenPosition::kMinSource;
+          desc.info.set_index(context_variable_index);
+          vars.Add(desc);
+        } break;
+      }
+    }
+  }
+
+  return vars.Done();
+}
+
+#endif  // !defined(PRODUCT) && !defined(DART_PRECOMPILED_RUNTIME)
+
 }  // namespace bytecode
 }  // namespace dart
 

runtime/vm/bytecode_reader.h

@@ -475,6 +475,14 @@ class BytecodeReader : public AllStatic {
   static void CollectScriptTokenPositionsFromBytecode(
       const Script& interesting_script,
       GrowableArray<intptr_t>* token_positions);
+
+#if !defined(PRODUCT) && !defined(DART_PRECOMPILED_RUNTIME)
+  // Compute local variable descriptors for [function] with [bytecode].
+  static LocalVarDescriptorsPtr ComputeLocalVarDescriptors(
+      Zone* zone,
+      const Function& function,
+      const Bytecode& bytecode);
+#endif
 };
 
 class BytecodeSourcePositionsIterator : ValueObject {
@@ -526,6 +534,125 @@ class BytecodeSourcePositionsIterator : ValueObject {
   bool is_yield_point_ = false;
 };
 
+#if !defined(PRODUCT) && !defined(DART_PRECOMPILED_RUNTIME)
+
+class BytecodeLocalVariablesIterator : ValueObject {
+ public:
+  // These constants should match corresponding constants in
+  // pkg/dart2bytecode/lib/local_variable_table.dart.
+  enum {
+    kInvalid,
+    kScope,
+    kVariableDeclaration,
+    kContextVariable,
+  };
+
+  static const intptr_t kKindMask = 0xF;
+  static const intptr_t kIsCapturedFlag = 1 << 4;
+
+  BytecodeLocalVariablesIterator(Zone* zone, const Bytecode& bytecode)
+      : reader_(TypedDataBase::Handle(zone, bytecode.binary())),
+        object_pool_(ObjectPool::Handle(zone, bytecode.object_pool())) {
+    if (bytecode.HasLocalVariablesInfo()) {
+      reader_.set_offset(bytecode.local_variables_binary_offset());
+      entries_remaining_ = reader_.ReadUInt();
+    }
+  }
+
+  bool MoveNext() {
+    if (entries_remaining_ <= 0) {
+      // Finished looking at the last entry, now we're done.
+      entries_remaining_ = -1;
+      return false;
+    }
+    --entries_remaining_;
+    cur_kind_and_flags_ = reader_.ReadByte();
+    cur_start_pc_ += reader_.ReadSLEB128();
+    switch (Kind()) {
+      case kScope:
+        cur_end_pc_ = cur_start_pc_ + reader_.ReadUInt();
+        cur_index_ = reader_.ReadSLEB128();
+        cur_token_pos_ = reader_.ReadPosition();
+        cur_end_token_pos_ = reader_.ReadPosition();
+        break;
+      case kVariableDeclaration:
+        cur_index_ = reader_.ReadSLEB128();
+        cur_name_ = reader_.ReadUInt();
+        cur_type_ = reader_.ReadUInt();
+        cur_declaration_token_pos_ = reader_.ReadPosition();
+        cur_token_pos_ = reader_.ReadPosition();
+        break;
+      case kContextVariable:
+        cur_index_ = reader_.ReadSLEB128();
+        break;
+    }
+    return true;
+  }
+
+  // Returns true after iterator moved past the last entry and
+  // MoveNext() returned false.
+  bool IsDone() const { return entries_remaining_ < 0; }
+
+  intptr_t Kind() const { return cur_kind_and_flags_ & kKindMask; }
+  bool IsScope() const { return Kind() == kScope; }
+  bool IsVariableDeclaration() const { return Kind() == kVariableDeclaration; }
+  bool IsContextVariable() const { return Kind() == kContextVariable; }
+
+  intptr_t StartPC() const { return cur_start_pc_; }
+  intptr_t EndPC() const {
+    ASSERT(IsScope() || IsVariableDeclaration());
+    return cur_end_pc_;
+  }
+  intptr_t ContextLevel() const {
+    ASSERT(IsScope());
+    return cur_index_;
+  }
+  TokenPosition StartTokenPos() const {
+    ASSERT(IsScope() || IsVariableDeclaration());
+    return cur_token_pos_;
+  }
+  TokenPosition EndTokenPos() const {
+    ASSERT(IsScope() || IsVariableDeclaration());
+    return cur_end_token_pos_;
+  }
+  intptr_t Index() const {
+    ASSERT(IsVariableDeclaration() || IsContextVariable());
+    return cur_index_;
+  }
+  StringPtr Name() const {
+    ASSERT(IsVariableDeclaration());
+    return String::RawCast(object_pool_.ObjectAt(cur_name_));
+  }
+  AbstractTypePtr Type() const {
+    ASSERT(IsVariableDeclaration());
+    return AbstractType::RawCast(object_pool_.ObjectAt(cur_type_));
+  }
+  TokenPosition DeclarationTokenPos() const {
+    ASSERT(IsVariableDeclaration());
+    return cur_declaration_token_pos_;
+  }
+  bool IsCaptured() const {
+    ASSERT(IsVariableDeclaration());
+    return (cur_kind_and_flags_ & kIsCapturedFlag) != 0;
+  }
+
+ private:
+  Reader reader_;
+  const ObjectPool& object_pool_;
+  intptr_t entries_remaining_ = 0;
+  intptr_t cur_kind_and_flags_ = 0;
+  intptr_t cur_start_pc_ = 0;
+  intptr_t cur_end_pc_ = 0;
+  intptr_t cur_index_ = -1;
+  intptr_t cur_name_ = -1;
+  intptr_t cur_type_ = -1;
+  TokenPosition cur_token_pos_ = TokenPosition::kNoSource;
+  TokenPosition cur_declaration_token_pos_ = TokenPosition::kNoSource;
+  TokenPosition cur_end_token_pos_ = TokenPosition::kNoSource;
+};
+
+#endif  // !defined(PRODUCT) && !defined(DART_PRECOMPILED_RUNTIME)
+
 }  // namespace bytecode
 }  // namespace dart
 

runtime/vm/compiler/runtime_offsets_extracted.h

@@ -634,7 +634,7 @@ static constexpr dart::compiler::target::word AbstractType_InstanceSize = 0x14;
 static constexpr dart::compiler::target::word ApiError_InstanceSize = 0x8;
 static constexpr dart::compiler::target::word Array_header_size = 0xc;
 static constexpr dart::compiler::target::word Bool_InstanceSize = 0x8;
-static constexpr dart::compiler::target::word Bytecode_InstanceSize = 0x30;
+static constexpr dart::compiler::target::word Bytecode_InstanceSize = 0x38;
 static constexpr dart::compiler::target::word Capability_InstanceSize = 0x10;
 static constexpr dart::compiler::target::word Class_InstanceSize = 0x78;
 static constexpr dart::compiler::target::word Closure_InstanceSize = 0x1c;
@@ -1362,7 +1362,7 @@ static constexpr dart::compiler::target::word AbstractType_InstanceSize = 0x28;
 static constexpr dart::compiler::target::word ApiError_InstanceSize = 0x10;
 static constexpr dart::compiler::target::word Array_header_size = 0x18;
 static constexpr dart::compiler::target::word Bool_InstanceSize = 0x10;
-static constexpr dart::compiler::target::word Bytecode_InstanceSize = 0x58;
+static constexpr dart::compiler::target::word Bytecode_InstanceSize = 0x60;
 static constexpr dart::compiler::target::word Capability_InstanceSize = 0x10;
 static constexpr dart::compiler::target::word Class_InstanceSize = 0xc8;
 static constexpr dart::compiler::target::word Closure_InstanceSize = 0x38;
@@ -2081,7 +2081,7 @@ static constexpr dart::compiler::target::word AbstractType_InstanceSize = 0x14;
 static constexpr dart::compiler::target::word ApiError_InstanceSize = 0x8;
 static constexpr dart::compiler::target::word Array_header_size = 0xc;
 static constexpr dart::compiler::target::word Bool_InstanceSize = 0x8;
-static constexpr dart::compiler::target::word Bytecode_InstanceSize = 0x30;
+static constexpr dart::compiler::target::word Bytecode_InstanceSize = 0x38;
 static constexpr dart::compiler::target::word Capability_InstanceSize = 0x10;
 static constexpr dart::compiler::target::word Class_InstanceSize = 0x78;
 static constexpr dart::compiler::target::word Closure_InstanceSize = 0x1c;
@@ -2811,7 +2811,7 @@ static constexpr dart::compiler::target::word AbstractType_InstanceSize = 0x28;
 static constexpr dart::compiler::target::word ApiError_InstanceSize = 0x10;
 static constexpr dart::compiler::target::word Array_header_size = 0x18;
 static constexpr dart::compiler::target::word Bool_InstanceSize = 0x10;
-static constexpr dart::compiler::target::word Bytecode_InstanceSize = 0x58;
+static constexpr dart::compiler::target::word Bytecode_InstanceSize = 0x60;
 static constexpr dart::compiler::target::word Capability_InstanceSize = 0x10;
 static constexpr dart::compiler::target::word Class_InstanceSize = 0xc8;
 static constexpr dart::compiler::target::word Closure_InstanceSize = 0x38;
@@ -3536,7 +3536,7 @@ static constexpr dart::compiler::target::word AbstractType_InstanceSize = 0x20;
 static constexpr dart::compiler::target::word ApiError_InstanceSize = 0x10;
 static constexpr dart::compiler::target::word Array_header_size = 0x10;
 static constexpr dart::compiler::target::word Bool_InstanceSize = 0x10;
-static constexpr dart::compiler::target::word Bytecode_InstanceSize = 0x40;
+static constexpr dart::compiler::target::word Bytecode_InstanceSize = 0x48;
 static constexpr dart::compiler::target::word Capability_InstanceSize = 0x10;
 static constexpr dart::compiler::target::word Class_InstanceSize = 0x80;
 static constexpr dart::compiler::target::word Closure_InstanceSize = 0x20;
@@ -4263,7 +4263,7 @@ static constexpr dart::compiler::target::word AbstractType_InstanceSize = 0x20;
 static constexpr dart::compiler::target::word ApiError_InstanceSize = 0x10;
 static constexpr dart::compiler::target::word Array_header_size = 0x10;
 static constexpr dart::compiler::target::word Bool_InstanceSize = 0x10;
-static constexpr dart::compiler::target::word Bytecode_InstanceSize = 0x40;
+static constexpr dart::compiler::target::word Bytecode_InstanceSize = 0x48;
 static constexpr dart::compiler::target::word Capability_InstanceSize = 0x10;
 static constexpr dart::compiler::target::word Class_InstanceSize = 0x80;
 static constexpr dart::compiler::target::word Closure_InstanceSize = 0x20;
@@ -4984,7 +4984,7 @@ static constexpr dart::compiler::target::word AbstractType_InstanceSize = 0x14;
 static constexpr dart::compiler::target::word ApiError_InstanceSize = 0x8;
 static constexpr dart::compiler::target::word Array_header_size = 0xc;
 static constexpr dart::compiler::target::word Bool_InstanceSize = 0x8;
-static constexpr dart::compiler::target::word Bytecode_InstanceSize = 0x30;
+static constexpr dart::compiler::target::word Bytecode_InstanceSize = 0x38;
 static constexpr dart::compiler::target::word Capability_InstanceSize = 0x10;
 static constexpr dart::compiler::target::word Class_InstanceSize = 0x78;
 static constexpr dart::compiler::target::word Closure_InstanceSize = 0x1c;
@@ -5713,7 +5713,7 @@ static constexpr dart::compiler::target::word AbstractType_InstanceSize = 0x28;
 static constexpr dart::compiler::target::word ApiError_InstanceSize = 0x10;
 static constexpr dart::compiler::target::word Array_header_size = 0x18;
 static constexpr dart::compiler::target::word Bool_InstanceSize = 0x10;
-static constexpr dart::compiler::target::word Bytecode_InstanceSize = 0x58;
+static constexpr dart::compiler::target::word Bytecode_InstanceSize = 0x60;
 static constexpr dart::compiler::target::word Capability_InstanceSize = 0x10;
 static constexpr dart::compiler::target::word Class_InstanceSize = 0xc8;
 static constexpr dart::compiler::target::word Closure_InstanceSize = 0x38;