[API] Fix -Werror=alloc-size-larger-than= warning in runtime_context.h

[marcalff]

Contributes to #2544

Changes

Please provide a brief description of the changes here.

For significant contributions please make sure you have completed the following items:

• CHANGELOG.md updated for non-trivial changes
• Unit tests have been added
• Changes in public API reviewed

[codecov]

Codecov Report

❌ Patch coverage is 44.44444% with 5 lines in your changes missing coverage. Please review.
✅ Project coverage is 89.90%. Comparing base (755411e) to head (5f23f20).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...pi/include/opentelemetry/context/runtime_context.h	44.45%	5 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3709      +/-   ##
==========================================
- Coverage   89.95%   89.90%   -0.05%     
==========================================
  Files         225      225              
  Lines        7273     7281       +8     
==========================================
+ Hits         6542     6545       +3     
- Misses        731      736       +5     

Files with missing lines	Coverage Δ
...pi/include/opentelemetry/context/runtime_context.h	92.31% <44.45%> (-5.28%)	⬇️

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[lalitb]

Just curious - should it return the last valid context, instead of empty one ?

[marcalff]

Good question.

In my understanding, Scope will attach and detach contexts on creation and destruction, adding/removing from the stack.

If the code returns the last valid context, then we will have:

• every scope nested at depth max_capacity_, max_capacity_ + 1, ..., max_capacity_ + N share the same context.
• Scope at max_capacity_ + N will destroy the last valid scope on destruction, causing side effects.

So, I think Top() and Pop() should return an empty context instead, once the stack depth goes beyond the limit.

This is very theoretical, because any process with 1 million nested scopes in the call stack will never reach this point, being long dead, already killed for other reasons (stack overflow, out of memory).

[lalitb]

LGTM. The edge case shouldn’t occur in any normal usage scenario :)

[Reneg973]

@marcalff
Did you see this line?
Resize(size_ * 2);