The `MRB_TT_BACKTRACE` object has been added for the purpose.
Previously, "use-after-free" could occur because the reference count in `backtrace_location::irep` was not incremented.
fixed#6160
Use stack variable addresses as identifiers instead of global variable values.
Since the stack variable address is uniquely determined within the call, there is no need to maintain a global variable.
This flag means all the characters in the string can be represented by a
single byte, i.e., the string does not contain any multi-byte character.
Those characters are likely ASCII characters, but may be a part of broken
UTF-8 sequence, so the term 'ASCII' is not sufficient.
If `Class#allocate` is prohibited, subclasses should also be implicitly prohibited.
```ruby
p Class.new(Struct).allocate.class
# => #<Class:0x82362ac00> by #6122
# => allocator undefined for #<Class:0x000000083a983220> (TypeError) by Ruby 3.2
```
Added `MRB_DEFINE_ALLOCATOR()` to allow subclasses to use `Class#allocate`.
Supplement to #6122.
The method introduced by #5979 causes a fault by swapping classes.
```console
% bin/mruby -e 'Method = Proc; p Object.method(:inspect)'
zsh: segmentation fault (core dumped) bin/mruby -e 'Method = Proc; p Object.method(:inspect)'
```
After applying this patch, a `TypeError` exception will be raised.
```console
% bin/mruby -e 'Method = Proc; p Object.method(:inspect)'
trace (most recent call last):
[1] -e:1
-e:1:in method: allocation failure of Proc (TypeError)
```
However, if the `mrb_vtype` is the same object, the same care must still be taken as before.
```console
% bin/mruby -e 'Method = Binding; p method(:puts).eval("12345")'
trace (most recent call last):
[1] -e:1
-e:1:in eval: wrong argument type nil (expected Proc) (TypeError)
```
It is now possible to specify return destination directly.
This allows callinfo to distinguish between calls to the same proc object.
At the same time, the `Kernel#catch` method is adjusted.
By removing the previously required double lambda object, the REnv object is no longer created as well.
Since it is confusing that the term `mrbc` stands for both "mruby
compiler" and "mruby compiler context" in the source code. Instead,
we use `mrb_ccontext` (stands for compiler context) prefix hereafter.
We choose `mrb_ccontext` because we have already used `mrb_context` (for
VM execusion context).
Since `Env` objects are shared by Blocks/Procs in the same context,
making multiple aliases in one context screws up with alias names.
New implementation uses alias bodies (Procs) to refer new names.
As a side effect, `__callee__` stop working correctly for aliases.
To fix this `__callee__` problem, we need to keep alias method names in
`callinfo`, which consumes more memory. We are wondering that is worth
the compatibility.
The function requires the buffer bigger than `mrb_packed_int_len()`
anyway, so we don't need boundary checks for each iteration. Should
makes the function a little bit faster.
Like previous recursive `<=>` check, scan call stack to detect recursive
`inspect` calls. We no longer need incomplete `_inspect` hack to pass
around a hash table to record objects currently inspecting.
Yukihiro "Matz" Matsumoto