Issue #17762 has been updated by Eregon (Benoit Daloze).


byroot (Jean Boussier) wrote in #note-11:
> Even though a the name is very slightly weird when put in context with `Method#source_location`, as `source` have a different meaning in both of these. But `allocation_location` would be even weirder I think.

I've thought about this too, but indeed `allocation_source_location` seems bad.

I guess if we do have a method on Object/Kernel it could simply be `Object#source_location` for consistency with Proc/Method/UnboundMethod/Module.
We could even have that method always defined potentially, and just return `nil` when no information is available.

----------------------------------------
Feature #17762: A simple way to trace object allocation
https://bugs.ruby-lang.org/issues/17762#change-91204

* Author: mame (Yusuke Endoh)
* Status: Open
* Priority: Normal
----------------------------------------
How about having a short hand to `ObjectSpace.trace_object_allocations_start`, `ObjectSpace.allocation_sourcefile` and `ObjectSpace.allocation_sourceline`?

They are a very powerful tool for debugging and code-reading which allows us to identify an allocation site of an object.
Though they are never lightweight, they are the last resort when you try debugging code written by someone else.

However, the names are too long for me to remember and to type. Whenever I want to use them, I have to google, copy and paste the names.

## Proposal

To enable trace allocations:

```
require "objspace/trace" #=> objspace/trace is enabled
```

To show the allocation site of an object:

```
p obj #=> #<Object:0x...> @ (file.rb):(lineno)
```

## Example

```
require "objspace/trace"
require "active_support/all"

p ActiveSupport::VERSION::STRING
  #=> "6.1.3.1" @ /home/mame/work/ruby/local/lib/ruby/gems/3.1.0/gems/activesupport-6.1.3.1/lib/active_support/gem_version.rb:15
```

## Discussion

I've attached a simple patch that is originally authored by @ko1 .

* Is the message `objspace/trace is enabled` needed or not?
* To stop the trace, you need to use `ObjectSpace.trace_object_allocations_stop`. But, I guess that it is rare that we need to stop it during debugging.
* Is it too radical to redefine `Kernel#p`? I think that it is good enough for many cases. When it matters, the original APIs (`ObjectSpace.trace_object_allocations_start`, ...) can be used.

---Files--------------------------------
objspace-trace.patch (631 Bytes)


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