1 files changed, 354 insertions, 0 deletions
diff --git a/js/src/vm/BytecodeLocation.h b/js/src/vm/BytecodeLocation.h
new file mode 100644
index 0000000000..e5876ed9d2
--- /dev/null
+++ b/js/src/vm/BytecodeLocation.h
@@ -0,0 +1,354 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef vm_BytecodeLocation_h
+#define vm_BytecodeLocation_h
+
+#include "frontend/NameAnalysisTypes.h"
+#include "js/TypeDecls.h"
+#include "vm/AsyncFunctionResolveKind.h"
+#include "vm/BuiltinObjectKind.h"
+#include "vm/BytecodeUtil.h"
+#include "vm/CheckIsObjectKind.h"   // CheckIsObjectKind
+#include "vm/CompletionKind.h"      // CompletionKind
+#include "vm/FunctionPrefixKind.h"  // FunctionPrefixKind
+#include "vm/GeneratorResumeKind.h"
+
+namespace js {
+
+using RawBytecodeLocationOffset = uint32_t;
+
+class PropertyName;
+class RegExpObject;
+
+class BytecodeLocationOffset {
+  RawBytecodeLocationOffset rawOffset_;
+
+ public:
+  explicit BytecodeLocationOffset(RawBytecodeLocationOffset offset)
+      : rawOffset_(offset) {}
+
+  RawBytecodeLocationOffset rawOffset() const { return rawOffset_; }
+};
+
+using RawBytecode = jsbytecode*;
+
+// A immutable representation of a program location
+//
+class BytecodeLocation {
+  RawBytecode rawBytecode_;
+#ifdef DEBUG
+  const JSScript* debugOnlyScript_;
+#endif
+
+  // Construct a new BytecodeLocation, while borrowing scriptIdentity
+  // from some other BytecodeLocation.
+  BytecodeLocation(const BytecodeLocation& loc, RawBytecode pc)
+      : rawBytecode_(pc)
+#ifdef DEBUG
+        ,
+        debugOnlyScript_(loc.debugOnlyScript_)
+#endif
+  {
+    MOZ_ASSERT(isValid());
+  }
+
+ public:
+  // Disallow the creation of an uninitialized location.
+  BytecodeLocation() = delete;
+
+  BytecodeLocation(const JSScript* script, RawBytecode pc)
+      : rawBytecode_(pc)
+#ifdef DEBUG
+        ,
+        debugOnlyScript_(script)
+#endif
+  {
+    MOZ_ASSERT(isValid());
+  }
+
+  RawBytecode toRawBytecode() const { return rawBytecode_; }
+
+#ifdef DEBUG
+  // Return true if this bytecode location is valid for the given script.
+  // This includes the location 1-past the end of the bytecode.
+  bool isValid(const JSScript* script) const;
+
+  // Return true if this bytecode location is within the bounds of the
+  // bytecode for a given script.
+  bool isInBounds(const JSScript* script) const;
+
+  const JSScript* getDebugOnlyScript() const;
+#endif
+
+  inline uint32_t bytecodeToOffset(const JSScript* script) const;
+
+  inline uint32_t tableSwitchCaseOffset(const JSScript* script,
+                                        uint32_t caseIndex) const;
+
+  inline uint32_t getJumpTargetOffset(const JSScript* script) const;
+
+  inline uint32_t getTableSwitchDefaultOffset(const JSScript* script) const;
+
+  inline BytecodeLocation getTableSwitchDefaultTarget() const;
+  inline BytecodeLocation getTableSwitchCaseTarget(const JSScript* script,
+                                                   uint32_t caseIndex) const;
+
+  inline uint32_t useCount() const;
+  inline uint32_t defCount() const;
+
+  int32_t jumpOffset() const { return GET_JUMP_OFFSET(rawBytecode_); }
+
+  inline JSAtom* getAtom(const JSScript* script) const;
+  inline JSString* getString(const JSScript* script) const;
+  inline PropertyName* getPropertyName(const JSScript* script) const;
+  inline JS::BigInt* getBigInt(const JSScript* script) const;
+  inline JSObject* getObject(const JSScript* script) const;
+  inline JSFunction* getFunction(const JSScript* script) const;
+  inline js::RegExpObject* getRegExp(const JSScript* script) const;
+  inline js::Scope* getScope(const JSScript* script) const;
+
+  uint32_t getSymbolIndex() const {
+    MOZ_ASSERT(is(JSOp::Symbol));
+    return GET_UINT8(rawBytecode_);
+  }
+
+  inline Scope* innermostScope(const JSScript* script) const;
+
+#ifdef DEBUG
+  bool hasSameScript(const BytecodeLocation& other) const {
+    return debugOnlyScript_ == other.debugOnlyScript_;
+  }
+#endif
+
+  // Overloaded operators
+
+  bool operator==(const BytecodeLocation& other) const {
+    MOZ_ASSERT(this->debugOnlyScript_ == other.debugOnlyScript_);
+    return rawBytecode_ == other.rawBytecode_;
+  }
+
+  bool operator!=(const BytecodeLocation& other) const {
+    return !(other == *this);
+  }
+
+  bool operator<(const BytecodeLocation& other) const {
+    MOZ_ASSERT(this->debugOnlyScript_ == other.debugOnlyScript_);
+    return rawBytecode_ < other.rawBytecode_;
+  }
+
+  // It is traditional to represent the rest of the relational operators
+  // using operator<, so we don't need to assert for these.
+  bool operator>(const BytecodeLocation& other) const { return other < *this; }
+
+  bool operator<=(const BytecodeLocation& other) const {
+    return !(other < *this);
+  }
+
+  bool operator>=(const BytecodeLocation& other) const {
+    return !(*this < other);
+  }
+
+  // Return the next bytecode
+  BytecodeLocation next() const {
+    return BytecodeLocation(*this,
+                            rawBytecode_ + GetBytecodeLength(rawBytecode_));
+  }
+
+  // Add an offset.
+  BytecodeLocation operator+(const BytecodeLocationOffset& offset) const {
+    return BytecodeLocation(*this, rawBytecode_ + offset.rawOffset());
+  }
+
+  // Identity Checks
+  bool is(JSOp op) const {
+    MOZ_ASSERT(isInBounds());
+    return getOp() == op;
+  }
+
+  // Accessors:
+
+  uint32_t length() const { return GetBytecodeLength(rawBytecode_); }
+
+  bool isJumpTarget() const { return BytecodeIsJumpTarget(getOp()); }
+
+  bool isJump() const { return IsJumpOpcode(getOp()); }
+
+  bool isBackedge() const { return IsBackedgePC(rawBytecode_); }
+
+  bool isBackedgeForLoophead(BytecodeLocation loopHead) const {
+    return IsBackedgeForLoopHead(rawBytecode_, loopHead.rawBytecode_);
+  }
+
+  bool opHasIC() const { return BytecodeOpHasIC(getOp()); }
+
+  bool fallsThrough() const { return BytecodeFallsThrough(getOp()); }
+
+  uint32_t icIndex() const { return GET_ICINDEX(rawBytecode_); }
+
+  uint32_t local() const { return GET_LOCALNO(rawBytecode_); }
+
+  uint16_t arg() const { return GET_ARGNO(rawBytecode_); }
+
+  bool isEqualityOp() const { return IsEqualityOp(getOp()); }
+
+  bool isStrictEqualityOp() const { return IsStrictEqualityOp(getOp()); }
+
+  bool isStrictSetOp() const { return IsStrictSetPC(rawBytecode_); }
+
+  bool isNameOp() const { return IsNameOp(getOp()); }
+
+  bool isSpreadOp() const { return IsSpreadOp(getOp()); }
+
+  bool isInvokeOp() const { return IsInvokeOp(getOp()); }
+
+  bool isGetPropOp() const { return IsGetPropOp(getOp()); }
+  bool isGetElemOp() const { return IsGetElemOp(getOp()); }
+
+  bool isSetPropOp() const { return IsSetPropOp(getOp()); }
+  bool isSetElemOp() const { return IsSetElemOp(getOp()); }
+
+  AsyncFunctionResolveKind getAsyncFunctionResolveKind() {
+    return AsyncFunctionResolveKind(GET_UINT8(rawBytecode_));
+  }
+
+  bool resultIsPopped() const {
+    MOZ_ASSERT(StackDefs(getOp()) == 1);
+    return BytecodeIsPopped(rawBytecode_);
+  }
+
+  // Accessors:
+  JSOp getOp() const { return JSOp(*rawBytecode_); }
+
+  BytecodeLocation getJumpTarget() const {
+    MOZ_ASSERT(isJump());
+    return BytecodeLocation(*this,
+                            rawBytecode_ + GET_JUMP_OFFSET(rawBytecode_));
+  }
+
+  // Return the 'low' parameter to the tableswitch opcode
+  int32_t getTableSwitchLow() const {
+    MOZ_ASSERT(is(JSOp::TableSwitch));
+    return GET_JUMP_OFFSET(rawBytecode_ + JUMP_OFFSET_LEN);
+  }
+
+  // Return the 'high' parameter to the tableswitch opcode
+  int32_t getTableSwitchHigh() const {
+    MOZ_ASSERT(is(JSOp::TableSwitch));
+    return GET_JUMP_OFFSET(rawBytecode_ + (2 * JUMP_OFFSET_LEN));
+  }
+
+  uint32_t getPopCount() const {
+    MOZ_ASSERT(is(JSOp::PopN));
+    return GET_UINT16(rawBytecode_);
+  }
+
+  uint32_t getDupAtIndex() const {
+    MOZ_ASSERT(is(JSOp::DupAt));
+    return GET_UINT24(rawBytecode_);
+  }
+
+  uint8_t getPickDepth() const {
+    MOZ_ASSERT(is(JSOp::Pick));
+    return GET_UINT8(rawBytecode_);
+  }
+  uint8_t getUnpickDepth() const {
+    MOZ_ASSERT(is(JSOp::Unpick));
+    return GET_UINT8(rawBytecode_);
+  }
+
+  uint32_t getEnvCalleeNumHops() const {
+    MOZ_ASSERT(is(JSOp::EnvCallee));
+    return GET_UINT8(rawBytecode_);
+  }
+
+  EnvironmentCoordinate getEnvironmentCoordinate() const {
+    MOZ_ASSERT(JOF_OPTYPE(getOp()) == JOF_ENVCOORD);
+    return EnvironmentCoordinate(rawBytecode_);
+  }
+
+  uint32_t getCallArgc() const {
+    MOZ_ASSERT(JOF_OPTYPE(getOp()) == JOF_ARGC);
+    return GET_ARGC(rawBytecode_);
+  }
+
+  uint32_t getInitElemArrayIndex() const {
+    MOZ_ASSERT(is(JSOp::InitElemArray));
+    uint32_t index = GET_UINT32(rawBytecode_);
+    MOZ_ASSERT(index <= INT32_MAX,
+               "the bytecode emitter must never generate JSOp::InitElemArray "
+               "with an index exceeding int32_t range");
+    return index;
+  }
+
+  FunctionPrefixKind getFunctionPrefixKind() const {
+    MOZ_ASSERT(is(JSOp::SetFunName));
+    return FunctionPrefixKind(GET_UINT8(rawBytecode_));
+  }
+
+  CheckIsObjectKind getCheckIsObjectKind() const {
+    MOZ_ASSERT(is(JSOp::CheckIsObj));
+    return CheckIsObjectKind(GET_UINT8(rawBytecode_));
+  }
+
+  BuiltinObjectKind getBuiltinObjectKind() const {
+    MOZ_ASSERT(is(JSOp::BuiltinObject));
+    return BuiltinObjectKind(GET_UINT8(rawBytecode_));
+  }
+
+  CompletionKind getCompletionKind() const {
+    MOZ_ASSERT(is(JSOp::CloseIter));
+    return CompletionKind(GET_UINT8(rawBytecode_));
+  }
+
+  uint32_t getNewArrayLength() const {
+    MOZ_ASSERT(is(JSOp::NewArray));
+    return GET_UINT32(rawBytecode_);
+  }
+
+  int8_t getInt8() const {
+    MOZ_ASSERT(is(JSOp::Int8));
+    return GET_INT8(rawBytecode_);
+  }
+  uint16_t getUint16() const {
+    MOZ_ASSERT(is(JSOp::Uint16));
+    return GET_UINT16(rawBytecode_);
+  }
+  uint32_t getUint24() const {
+    MOZ_ASSERT(is(JSOp::Uint24));
+    return GET_UINT24(rawBytecode_);
+  }
+  int32_t getInt32() const {
+    MOZ_ASSERT(is(JSOp::Int32));
+    return GET_INT32(rawBytecode_);
+  }
+  uint32_t getResumeIndex() const {
+    MOZ_ASSERT(is(JSOp::InitialYield) || is(JSOp::Yield) || is(JSOp::Await));
+    return GET_RESUMEINDEX(rawBytecode_);
+  }
+  Value getInlineValue() const {
+    MOZ_ASSERT(is(JSOp::Double));
+    return GET_INLINE_VALUE(rawBytecode_);
+  }
+
+  GeneratorResumeKind resumeKind() { return ResumeKindFromPC(rawBytecode_); }
+
+  ThrowMsgKind throwMsgKind() {
+    MOZ_ASSERT(is(JSOp::ThrowMsg));
+    return static_cast<ThrowMsgKind>(GET_UINT8(rawBytecode_));
+  }
+
+#ifdef DEBUG
+  // To ease writing assertions
+  bool isValid() const { return isValid(debugOnlyScript_); }
+
+  bool isInBounds() const { return isInBounds(debugOnlyScript_); }
+#endif
+};
+
+}  // namespace js
+
+#endif