Skip to content

Derive conditional expression guards from the branch set difference #6380

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
ondrejmirtes merged 8 commits into from
Sep 11, 2026
Merged

Derive conditional expression guards from the branch set difference #6380

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
8 commits
Select commit Hold shift + click to select a range
d6831e9
Derive conditional guard types from the branch set difference
ondrejmirtes Sep 5, 2026
f010107
Port set-difference guard selection to the native ScopeOps
ondrejmirtes Sep 5, 2026
0f5817a
Bump expected turbo version
ondrejmirtes Sep 5, 2026
a8e647b
Resolve self-analysis findings surfaced by sharper conditional guards
ondrejmirtes Sep 5, 2026
d3c0b9d
Restore SubstrDynamicReturnTypeExtension behavior and baseline its fi…
ondrejmirtes Sep 5, 2026
f15cc3c
Add regression test(s) for collateral fix(es) #8360
ondrejmirtes Sep 5, 2026
ae4ff1c
Update expectation: sharper narrowing catches a float-to-string prope…
ondrejmirtes Sep 5, 2026
f772f3c
Compute constant substr() result independently of the runtime PHP ver…
ondrejmirtes Sep 5, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Prev Previous commit
Next Next commit
Restore SubstrDynamicReturnTypeExtension behavior and baseline its fi… 
…nding

The previous commit removed the empty-string branch under `is_bool($substr)`
as dead code, reasoning that `$substr` is a bool only where
`substrReturnFalseInsteadOfEmptyString()` is true. That is a real regression:
the branch is live when PHPStan itself runs on a runtime PHP whose native
`substr()` returns `false` (old runtime) while analysing a target version
where substr yields `''`. There the runtime `substr()` call produces a bool,
`substrReturnFalseInsteadOfEmptyString()` is false, and the else branch
simulates the modern result by returning ConstantStringType(''). PHPStan's own
inference models `substr()` per the analysed version and cannot see the old
runtime path, so it reports the guard as always-true - a finding that must be
baselined, not resolved by deleting the branch.

Restore the file to its exact pre-commit content and record the single
`if.alwaysTrue` finding in the baseline instead. The other seven dead-code
removals in the previous commit are genuinely dead and stay removed.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CGhnJQpUWRRpg6H5LuWJkA
  • Loading branch information
@ondrejmirtes @claude
ondrejmirtes and claude committed Sep 11, 2026
commit d3c0b9dde12bad71a0f6015d11a05435da465090
6 changes: 6 additions & 0 deletions phpstan-baseline.neon
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1566,6 +1566,12 @@ parameters:
count: 1
path: src/Type/Php/ReflectionMethodConstructorThrowTypeExtension.php

-
rawMessage: If condition is always true.
identifier: if.alwaysTrue
count: 1
path: src/Type/Php/SubstrDynamicReturnTypeExtension.php

-
rawMessage: 'Doing instanceof PHPStan\Type\ObjectType is error-prone and deprecated. Use Type::isObject() or Type::getObjectClassNames() instead.'
identifier: phpstanApi.instanceofType
Expand Down
7 changes: 6 additions & 1 deletion src/Type/Php/SubstrDynamicReturnTypeExtension.php
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -95,7 +95,12 @@ public function getTypeFromFunctionCall(
}

if (is_bool($substr)) {
$results[] = new ConstantBooleanType($substr);
if ($this->phpVersion->substrReturnFalseInsteadOfEmptyString()) {
$results[] = new ConstantBooleanType($substr);
} else {
// Simulate substr call on a recent PHP version if the runtime one is too old.
$results[] = new ConstantStringType('');
}
} else {
$results[] = new ConstantStringType($substr);
}
Expand Down