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`.
TODO:
- [ ] test writing of .nif files
- [x] implement loading of fields in PType/PSym that might not have been
loaded
- [ ] implement interface logic
- [ ] implement pragma "replays"
- [ ] implement special logic for `converter`
- [ ] implement special logic for `method`
- [ ] test the logic holds up for `export`
- [ ] implement logic to free the memory of PSym/PType if memory
pressure is high
- [ ] implement logic to close memory mapped files if too many are open.
---------
Co-authored-by: demotomohiro <gpuppur@gmail.com>
Co-authored-by: ringabout <43030857+ringabout@users.noreply.github.com>
Co-authored-by: Jacek Sieka <arnetheduck@gmail.com>
* refactoring in preparation for better, simpler name mangling that works with IC flawlessly
* use new disamb field
* see if this makes tests green
* make tests green again
* Fix bug in freshVarForClosureIter. Fixes#18474.
freshVarForClosureIter was returning non-fresh symbols sometimes.
Fixed by making addField return the generated PSym.
* remove discardable
Co-authored-by: Nick Smallbone <nick@smallbone.se>
* IC: renamed to_packed_ast module to ic module
* IC: don't store the --forceBuild flag, makes it easier to test
* IC: enable hello world test
* Codegen: refactorings for IC; changed the name mangling algorithm
* fixed the HCR regressions
* life is too short for HCR
* tconvexhull is now allowed to use deepCopy
* IC exposed a stdlib bug, required a refactoring
* codegen: code cleanups
* IC: even if a module is outdated, its dependencies might come from disk
* IC: progress
* IC: better name mangling, module IDs are not stable
* IC: another refactoring helping with --ic:on --gc:arc
* disable arraymancer on Windows for the time being
* disable arraymancer altogether
* IC: make basic test work with 'nim cpp'
* IC: progress on --ic:on --gc:arc
* wip; name mangling for type info
* reworked ID handling
* the packed AST now has its own ID mechanism
* basic serialization code works
* extract rodfiles to its own module
* rodfiles: store and compare configs
* rodfiles: store dependencies
* store config at the end
* precise dependency tracking
* dependency tracking for rodfiles
* completed loading of PSym, PType, etc
* removed dead code
* bugfix: do not realloc seqs when taking addr into an element
* make IC opt-in for now
* makes tcompilerapi green again
* final cleanups
Co-authored-by: Andy Davidoff <github@andy.disruptek.com>
* refactoring: idents don't need inheritance
* refactoring: adding an IdGenerator (part 1)
* refactoring: adding an IdGenerator (part 2)
* refactoring: adding an IdGenerator (part 3)
* refactoring: adding an IdGenerator (part 4)
* refactoring: adding an IdGenerator (part 5)
* refactoring: adding an IdGenerator (part 5)
* IdGenerator must be a ref type; hello world works again
* make bootstrapping work again
* progress: add back the 'exactReplica' ideas
* added back the missing exactReplica hacks
* make tcompilerapi work again
* make important packages green
* attempt to fix the build for 32 bit machines (probably need a better solution here)
* I don't care about observable stores
* enforce explicit initializations
* cleaner code for the stdlib
* stdlib: use explicit initializations
* make tests green
* algorithm.nim: set result explicitly
* remove out parameters and bring the PR into a mergable state
* updated the changelog
* drnim: tiny progress
* refactoring complete
* drnim: prove .ensures annotations
* Moved code around to avoid code duplication
* drnim: first implementation of the 'old' property
* drnim: be precise about the assignment statement
* first implementation of --assumeUnique
* progress on forall/exists handling
