How to debug V8 with source code view using WinDbg?
I was looking into learning more about V8 internals and I have tired to set up a debug environment to help me with that, but I'm relatively new to all that so I'm not sure if I'm doing it right.
I have compiled V8 with the debug flag set to true and have run D8 to test the build out. After attaching WinDbg to the D8 process, I have set a breakpoints on Math.hypot (v8!Builtins_MathHypot) function to try to see how it works:
My question is: the source code for most of the functions in the call stack is linked and I can debug them by navigating through either assembly or source code (you can also see the path to the source code in the call stack next to the function). But for v8!Builtins_*, there is no source code displayed. Am I doing something wrong or is that intended? Is there a way to make the source code view work for these functions too?
V8 developer here. There are different kinds of builtins: some of them are handwritten assembly, or generated at compile time using the "CodeStubAssembler" infrastructure; others are implemented in C++. For the latter, you should be able to see the source. MathHypot is among them, so I don't know why that isn't working (I don't use WinDbg). Maybe it's because the function entry is generated from a macro; try setting your breakpoint to a line of actual C++ source code, in this case builtins-math.cc:18.
For JSEntry, JSEntryTrampoline, and InterpreterEntryTrampoline, it's expected that there is no source.
You can see the list of builtins, including their type, in src/builtins/builtins-definitions.h.
- How to force JavaScript to deep copy a string?
- chrome javascript optimization deep magic
- Why this huge performance difference for an encapsulated Javascript function?
- Can you check if a JavaScript number is 32 bits?
- V8 vs NativeClient
- v8::internal::Isolate::Exit() Segfault when compiling with clang
- Generated code performing with simulator mode and without in V8
- How does FunctionTemplate::GetFunction may return something?
- Access JavaScript array in v8 C++ function handler
- How does the parameter const v8::FunctionCallbackInfo<v8::Value>& args get its value at the C++ level?
- Where primitives inside objects are actually stored
- can a js URL object be a long number?
- What's the maximum size of a Node.js Buffer
- How do I extract the URL element from V8 script object
- Why is an inline cache for retrieving property from an object invalidated whenever someone changes any prototype above it, not below it?
- what functions will be called in v8 source code when run JavaScript code?
- Why is JavaScript executing callbacks in a for-loop so fast the first time?
- Running V8 Javascript Engine Standalone
- Is it possible to build Google V8 engine using Microsoft VC++ compiler?
- JS string concatenation optimization
- OptimizeFunctionOnNextCall() and PrepareFunctionForOptimization() + OptimizeFunctionOnNextCall()
- Control optimization in V8's TurboFan
- Why Does Stack Size Vary By Function (V8 Engine)?
- Why is pre-allocation of arrays slower than dynamic pushing in JavaScript?
- rusty_v8 TryCatch not catching heap limit
- Why are random integers generated by multiplying by MAX_SAFE_INTEGER not evenly distributed between odd and even?
- How to embed V8 in a Java application?
- Nodejs - Increase heap size in express.js project
- Are there any precompiled binaries for V8?
- how nodejs actually interacts with the v8 engine