v8/include/v8-debug.h

// Copyright 2021 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef INCLUDE_V8_DEBUG_H_
#define INCLUDE_V8_DEBUG_H_

#include <stdint.h>

#include <span>

#include "v8-script.h"  // NOLINT(build/include_directory)
#include "v8config.h"   // NOLINT(build/include_directory)

namespace v8 {

class Isolate;
class String;

/**
 * A single JavaScript stack frame.
 */
class V8_EXPORT StackFrame {
 public:
  /**
   * Returns the source location, 0-based, for the associated function call.
   */
  Location GetLocation() const;

  /**
   * Returns the number, 1-based, of the line for the associate function call.
   * This method will return Message::kNoLineNumberInfo if it is unable to
   * retrieve the line number, or if kLineNumber was not passed as an option
   * when capturing the StackTrace.
   */
  int GetLineNumber() const { return GetLocation().GetLineNumber() + 1; }

  /**
   * Returns the 1-based column offset on the line for the associated function
   * call.
   * This method will return Message::kNoColumnInfo if it is unable to retrieve
   * the column number, or if kColumnOffset was not passed as an option when
   * capturing the StackTrace.
   */
  int GetColumn() const { return GetLocation().GetColumnNumber() + 1; }

  /**
   * Returns zero based source position (character offset) for the associated
   * function.
   */
  int GetSourcePosition() const;

  /**
   * Returns the id of the script for the function for this StackFrame.
   * This method will return Message::kNoScriptIdInfo if it is unable to
   * retrieve the script id, or if kScriptId was not passed as an option when
   * capturing the StackTrace.
   */
  int GetScriptId() const;

  /**
   * Returns the name of the resource that contains the script for the
   * function for this StackFrame.
   */
  Local<String> GetScriptName() const;

  /**
   * Returns the name of the resource that contains the script for the
   * function for this StackFrame or sourceURL value if the script name
   * is undefined and its source ends with //# sourceURL=... string or
   * deprecated //@ sourceURL=... string.
   */
  Local<String> GetScriptNameOrSourceURL() const;

  /**
   * Returns the source of the script for the function for this StackFrame.
   */
  Local<String> GetScriptSource() const;

  /**
   * Returns the source mapping URL (if one is present) of the script for
   * the function for this StackFrame.
   */
  Local<String> GetScriptSourceMappingURL() const;

  /**
   * Returns the name of the function associated with this stack frame.
   */
  Local<String> GetFunctionName() const;

  /**
   * Returns whether or not the associated function is compiled via a call to
   * eval().
   */
  bool IsEval() const;

  /**
   * Returns whether or not the associated function is called as a
   * constructor via "new".
   */
  bool IsConstructor() const;

  /**
   * Returns whether or not the associated functions is defined in wasm.
   */
  bool IsWasm() const;

  /**
   * Returns whether or not the associated function is defined by the user.
   */
  bool IsUserJavaScript() const;

  /**
   * Returns whether the script was compiled with resource_is_opaque set in its
   * ScriptOrigin.
   */
  bool IsScriptOpaque() const;
};

/**
 * Representation of a JavaScript stack trace. The information collected is a
 * snapshot of the execution stack and the information remains valid after
 * execution continues.
 */
class V8_EXPORT StackTrace {
 public:
  /**
   * Flags that determine what information is placed captured for each
   * StackFrame when grabbing the current stack trace.
   * Note: these options are deprecated and we always collect all available
   * information (kDetailed).
   */
  enum StackTraceOptions {
    kLineNumber = 1,
    kColumnOffset = 1 << 1 | kLineNumber,
    kScriptName = 1 << 2,
    kFunctionName = 1 << 3,
    kIsEval = 1 << 4,
    kIsConstructor = 1 << 5,
    kScriptNameOrSourceURL = 1 << 6,
    kScriptId = 1 << 7,
    kExposeFramesAcrossSecurityOrigins = 1 << 8,
    kOverview = kLineNumber | kColumnOffset | kScriptName | kFunctionName,
    kDetailed = kOverview | kIsEval | kIsConstructor | kScriptNameOrSourceURL
  };

  struct ScriptIdAndContext {
    int id;
    v8::Local<v8::Context> context;
  };

  struct ScriptData {
    int id;
    v8::Local<v8::Function> function;
    v8::Local<v8::Context> context;
  };

  /**
   * Returns the (unique) ID of this stack trace.
   */
  int GetID() const;

  /**
   * Returns a StackFrame at a particular index.
   */
  Local<StackFrame> GetFrame(Isolate* isolate, uint32_t index) const;

  /**
   * Returns the number of StackFrames.
   */
  int GetFrameCount() const;

  /**
   * Grab a snapshot of the current JavaScript execution stack.
   *
   * \param frame_limit The maximum number of stack frames we want to capture.
   * \param options Enumerates the set of things we will capture for each
   *   StackFrame.
   */
  static Local<StackTrace> CurrentStackTrace(
      Isolate* isolate, int frame_limit, StackTraceOptions options = kDetailed);

  /**
   * Returns the first valid script name or source URL starting at the top of
   * the JS stack. The returned string is either an empty handle if no script
   * name/url was found or a non-zero-length string.
   *
   * This method is equivalent to calling StackTrace::CurrentStackTrace and
   * walking the resulting frames from the beginning until a non-empty script
   * name/url is found. The difference is that this method won't allocate
   * a stack trace.
   */
  static Local<String> CurrentScriptNameOrSourceURL(Isolate* isolate);

  /**
   * Returns the first valid script id at the top of the JS stack. The returned
   * value is Message::kNoScriptIdInfo if no id was found.
   *
   * This method is equivalent to calling StackTrace::CurrentStackTrace and
   * walking the resulting frames from the beginning until a non-empty id is
   * found. The difference is that this method won't allocate a stack trace.
   */
  static int CurrentScriptId(Isolate* isolate);

  /**
   * Writes up to the first `frame_data.size()` valid script ids and function
   * contexts at the top of the JS stack into the given span. Returns a span
   * sized to the number of frames worth of data written. It's similar to the
   * CurrentStackTrace method but doesn't allocate a stack trace. Further, it
   * skips frames that don't have valid script ids or function contexts. The
   * final difference is that the script id written for evals or regexp is that
   * of the script that ran eval() or regexp, not the current context.
   *
   */
  V8_DEPRECATE_SOON("Use CurrentScriptData instead")
  static std::span<v8::StackTrace::ScriptIdAndContext>
  CurrentScriptIdsAndContexts(Isolate* isolate,
                              std::span<ScriptIdAndContext> frame_data);

  /**
   * Writes up to the first `frame_data.size()` valid script ids, functions, and
   * contexts at the top of the JS stack into the given span. Returns a span
   * sized to the number of frames worth of data written. It's similar to the
   * CurrentStackTrace method but doesn't allocate a stack trace. Further, it
   * skips non-js frames and frames that don't have valid script ids or function
   * contexts. The final difference is that the script id written for evals or
   * regexp is that of the script that ran eval() or regexp, not the current
   * context.
   *
   * WARNING: This is an unfinished experimental feature. Semantics and
   * implementation may change frequently.
   */
  static std::span<v8::StackTrace::ScriptData> CurrentScriptData(
      Isolate* isolate, std::span<ScriptData> frame_data);
};

}  // namespace v8

#endif  // INCLUDE_V8_DEBUG_H_