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aaa741ca88
fixes #25857
## Bug
`typeof(result)` inside the expression that builds `result` gets counted
as a read
of `result` before it's set. On a `{.requiresInit.}` return type that's
a hard error
("'result' requires explicit initialization"). `typeof` never evaluates
its operand,
so it's a false positive. On 2.2.4 it compiles, but the same line still
emits a bogus
`ProveInit` warning, so no released version gets it right.
Regression from #25151. That PR made a used-before-init `requiresInit`
result a hard
error instead of a warning, which is correct on its own. The side effect
was that
this old false-positive warning became a build error.
## Root cause
`track` in `compiler/sempass2.nim` has no arm for `nkTypeOfExpr`, so it
hits the
default that recurses into every child, reaches the `result` `nkSym`
inside the
`typeof`, and calls `useVar`. `sizeof`/`compiles`/`declared` don't hit
this because
they fold to a constant before `track` runs. A `typeof(result)` typedesc
argument
survives into `track`.
## Fix
Skip `nkTypeOfExpr` in `track`. Its operand is never evaluated, so it
isn't a
definite-assignment use. After the patch there's no error and no warning
here, even
with `--warnings:on`. The #25151 check is untouched: a real use of
`result` before
init is a plain `nkSym`, not inside a `typeof`, so it still reaches
`useVar`.
## Test
`tests/init/t25857.nim`, a positive test that compiles and prints `1`.
## Checks
- Repro compiles and runs on patched 2.2.6 and patched devel.
- `tests/errmsgs/t25117.nim` still fails as expected. A real
`xxx(result)` before
init still errors.
- `testament cat init` and `testament cat errmsgs` green on patched
devel (55 tests,
0 failures), including the `--warningAsError:ProveInit` tests.
- Bisect: parent `1ab68797` good, `576c4018` (#25151) bad.
(cherry picked from commit 73986c03a1)
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.