From: "mame (Yusuke Endoh) via ruby-core" <ruby-core@...>
Date: 2024-01-19T05:39:36+00:00
Subject: [ruby-core:116312] [Ruby master Feature#19117] Include the method owner in backtraces, not just the method name

Issue #19117 has been updated by mame (Yusuke Endoh).


I prototyped this proposal: https://github.com/ruby/ruby/pull/9605

Fortunately, this would bring neither perrformance degredation nor extra memory usage when an exception is raised because I just replaced the method id with the method entry object in Thread::Backtrace::Location. (To get the method id, we need to read it via the method entry object, but I believe it is ignorable.)

The notation is as follows.

* Instance methods of named classes are `ClassName#method_name`.
* Class methods for named classes are `ClassName.method_name`.
* Only `method_name` otherwise

I think I properly support `block in ClassName#method_name` and so on.

```
$ cat test.rb
def toplevel = raise

class Foo
  def self.class_meth = toplevel

  def instance_meth = Foo.class_meth
end

obj = Foo.new

def obj.singleton_meth = instance_meth

obj.singleton_meth

$ ./miniruby test.rb
test.rb:1:in 'Object#toplevel': unhandled exception
        from test.rb:4:in 'Foo.class_meth'
        from test.rb:6:in 'Foo#instance_meth'
        from test.rb:11:in 'singleton_meth'
        from test.rb:13:in '<main>'
```

@byroot What do you think?

This causes some tests to fail, but I haven't fixed the test yet.

----------------------------------------
Feature #19117: Include the method owner in backtraces, not just the method name
https://bugs.ruby-lang.org/issues/19117#change-106336

* Author: byroot (Jean Boussier)
* Status: Open
* Priority: Normal
* Target version: 3.4
----------------------------------------
```
module Foo
  class Bar
    def inspect
      1 + '1'
    end
  end
end

p Foo::Bar.new
```

This code produce the following backtrace:


```
/tmp/foo.rb:4:in `+': String can't be coerced into Integer (TypeError)
	from /tmp/foo.rb:4:in `inspect'
	from /tmp/foo.rb:9:in `p'
	from /tmp/foo.rb:9:in `<main>'
```

This works, but on large codebases and large backtraces the method name isn't always all that revealing, most of the time you need to open many of the locations listed in the backtrace to really understand what is going on.

I propose that we also include the owner name:

```
/tmp/foo.rb:4:in `Integer#+': String can't be coerced into Integer (TypeError)
	from /tmp/foo.rb:4:in `Foo::Bar#inspect'
	from /tmp/foo.rb:9:in `Kernel#p'
	from /tmp/foo.rb:9:in `<main>'
```

I believe that in many case it would allow to much better understand the backtrace without having to jump back and forth between it and the source code.

This is inspired by @ivoanjo 's `backtracie` gem: https://github.com/ivoanjo/backtracie



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