fixes #25800 closes https://github.com/nim-lang/Nim/pull/25807 ref https://github.com/nim-lang/Nim/issues/25800 This pull request improves the handling of move semantics and the `=wasMoved` hook in the Nim compiler, especially for C++ code generation and user-defined types. It refactors the move operation logic to better support custom hooks, adds new tests for edge cases, and ensures that the `move` operation is safer and more predictable. **Move semantics and `=wasMoved` handling:** * Refactored the move operation in `compiler/ccgexprs.nim` by introducing helper procs (`canGenMoveCall`, `genMoveCall`, `genWasMovedCall`, `genMoveWithWasMoved`) to better handle cases with user-defined `=wasMoved` hooks, especially for generics and C++ interop. The logic now distinguishes between simple assignments and when to call custom hooks, improving correctness and maintainability. [[1]](diffhunk://#diff-4509107d295d7d32b1887c8993cd0f56113ae60f36113e7d8778646dabd92ebcL2818-R2851) [[2]](diffhunk://#diff-4509107d295d7d32b1887c8993cd0f56113ae60f36113e7d8778646dabd92ebcL2841-R2882) * Updated the `move` proc in `lib/system.nim` to include the `nodestroy` pragma, preventing double destruction and making move semantics safer. **Testing and validation:** * Added a new test (`tests/ccgbugs2/t25800.nim`) to ensure that user-defined `=wasMoved` hooks with `{.importcpp.}` are correctly generated and invoked in C++ code, addressing a specific bug with invalid preprocessor directives. * Expanded `tests/destructor/twasmoved.nim` with additional test cases for objects with and without custom `=wasMoved` hooks, including multithreaded scenarios using `threadpool`, to verify correct behavior in a variety of contexts. **Minor cleanup:** * Added a blank line for code style consistency in `compiler/semmagic.nim`.
This directory contains the test cases.
Each test must have a filename of the form: t*.nim
Note: Testament is only aware of tests under a directory (eg tests/foo/) and will ignore
top-level tests like tests/tbar.nim.
Specs
Each test can contain a spec in a discard """ ... """ block.
Check out the parseSpec procedure in the specs module for a full and reliable reference
action
Specifies what action this test should take.
Default: run
Options:
compile- compiles the module and fails the test if compilations fails.run- compiles and runs the module, fails the test if compilation or execution of test code fails.reject- compiles the module and fails the test if compilation succeeds.
There are certain spec keys that imply run, including output and
outputsub.
Categories
Each folder under this directory represents a test category, which can be
tested by running koch tests pcat <category> (or cat to avoid parallel
testing, which is slower).
The folder dll contains simple DLL tests.
The folder realtimeGC contains a test for validating that the realtime GC
can run properly without linking against the nimrtl.dll/so.