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Merged
staabm merged 3 commits into from
Oct 7, 2026
+66 −12
Merged

Read the updated value of consumed prefix mutations #6692

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9f63407
Read the updated value of consumed prefix mutations
drewmt Oct 6, 2026
ad373c1
Bump expected turbo version
drewmt Oct 6, 2026
f4a22bc
Specify integer offsets in prefix mutation regression
drewmt Oct 6, 2026
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6 changes: 5 additions & 1 deletion src/Analyser/ExprHandler/PreDecHandler.php
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Original file line number Diff line number Diff line change
Expand Up @@ -90,7 +90,11 @@ public function processExpr(NodeScopeResolver $nodeScopeResolver, Stmt $stmt, Ex
$assignedScope,
beforeScope: $scope,
expr: $expr,
variableFlow: VariableFlow::sequence($varResult->getVariableFlow(), $valueFlowWrite !== null && $context->isValueConsumed() ? VariableFlow::inputs($valueFlowWrite->getId(), $context->getValueFlowTarget() !== null ? $context->getValueFlowTarget()->getId() : null) : null, VariableFlowBuilder::targetWrite($expr->var, VariableWrite::KIND_PRE_DEC, $assignedScope, $storage)),

@staabm staabm Oct 7, 2026 •
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maybe there is some code-style rule we could enforce so such long expressions will be split over more lines by default - which would ease reading diffs in such lines (separate PR)

@drewmt drewmt Oct 7, 2026

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Thanks for reviewing! Agreed, a separate formatting-rule PR would keep this fix focused and make future diffs easier to read.

variableFlow: VariableFlow::sequence(
$varResult->getVariableFlow(),
VariableFlowBuilder::targetWrite($expr->var, VariableWrite::KIND_PRE_DEC, $assignedScope, $storage),
$valueFlowWrite !== null && $context->isValueConsumed() ? VariableFlowBuilder::targetRead($expr->var, $storage, true, $context->getValueFlowTarget() !== null ? $context->getValueFlowTarget()->getId() : null) : null,
),
hasYield: $varResult->hasYield(),
isAlwaysTerminating: $varResult->isAlwaysTerminating(),
throwPoints: $varResult->getThrowPoints(),
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6 changes: 5 additions & 1 deletion src/Analyser/ExprHandler/PreIncHandler.php
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Original file line number Diff line number Diff line change
Expand Up @@ -90,7 +90,11 @@ public function processExpr(NodeScopeResolver $nodeScopeResolver, Stmt $stmt, Ex
$assignedScope,
beforeScope: $scope,
expr: $expr,
variableFlow: VariableFlow::sequence($varResult->getVariableFlow(), $valueFlowWrite !== null && $context->isValueConsumed() ? VariableFlow::inputs($valueFlowWrite->getId(), $context->getValueFlowTarget() !== null ? $context->getValueFlowTarget()->getId() : null) : null, VariableFlowBuilder::targetWrite($expr->var, VariableWrite::KIND_PRE_INC, $assignedScope, $storage)),
variableFlow: VariableFlow::sequence(
$varResult->getVariableFlow(),
VariableFlowBuilder::targetWrite($expr->var, VariableWrite::KIND_PRE_INC, $assignedScope, $storage),
$valueFlowWrite !== null && $context->isValueConsumed() ? VariableFlowBuilder::targetRead($expr->var, $storage, true, $context->getValueFlowTarget() !== null ? $context->getValueFlowTarget()->getId() : null) : null,
),
hasYield: $varResult->hasYield(),
isAlwaysTerminating: $varResult->isAlwaysTerminating(),
throwPoints: $varResult->getThrowPoints(),
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2 changes: 1 addition & 1 deletion src/Turbo/TurboExtensionEnabler.php
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Expand Up @@ -33,7 +33,7 @@
final class TurboExtensionEnabler
{

public const EXPECTED_EXTENSION_VERSION = '12acf37';
public const EXPECTED_EXTENSION_VERSION = '9f63407';

private static bool $active = false;

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5 changes: 5 additions & 0 deletions tests/PHPStan/Rules/DeadCode/UnusedVariableRuleTest.php
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Expand Up @@ -18,6 +18,11 @@ protected function getRule(): Rule
return new UnusedVariableRule(self::getContainer()->getByType(ExprPrinter::class));
}

public function testBug15411(): void
{
$this->analyse([__DIR__ . '/data/bug-15411.php'], []);
}

public function testThrowableCatchAfterDocumentedException(): void
{
$this->analyse([__DIR__ . '/data/unused-variable-throwable-catch.php'], []);
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41 changes: 41 additions & 0 deletions tests/PHPStan/Rules/DeadCode/data/bug-15411.php
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Original file line number Diff line number Diff line change
@@ -0,0 +1,41 @@
<?php declare(strict_types = 1);

namespace Bug15411;

function nextCookieValue(int $count): string
{
return (string) ++$count;
}

echo nextCookieValue(1);

function previousCookieValue(int $count): string
{
return (string) --$count;
}

echo previousCookieValue(1);

function nextAssignedValue(int $count): int
{
$value = ++$count;
return $value;
}

function previousAssignedValue(int $count): int
{
$value = --$count;
return $value;
}

/** @param array{count: int} $counts */
function nextOffsetValue(array $counts): int
{
return ++$counts['count'];
}

/** @param array{count: int} $counts */
function previousOffsetValue(array $counts): int
{
return --$counts['count'];
}
2 changes: 1 addition & 1 deletion turbo-ext/src/PreDecHandler.cpp
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Expand Up @@ -102,7 +102,7 @@ class PreDecHandler
zv::Val assignedScope = ptse::scopeOf(assignResult.raw());
if (UNEXPECTED(assignedScope.isUndef())) return zv::Val();

zv::Val variableFlow = ptse::incDecFlow(child.variableFlow.raw(), valueFlowWrite.raw(), context, var, pt_pdh_kind, assignedScope.raw(), storage);
zv::Val variableFlow = ptse::incDecFlow(child.variableFlow.raw(), valueFlowWrite.raw(), context, var, pt_pdh_kind, assignedScope.raw(), storage, true);
if (UNEXPECTED(variableFlow.isUndef())) return zv::Val();
zv::Val dependenciesHold;
zval *dependencies = pt_expression_result_dependencies(varResult.raw(), dependenciesHold);
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2 changes: 1 addition & 1 deletion turbo-ext/src/PreIncHandler.cpp
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Expand Up @@ -102,7 +102,7 @@ class PreIncHandler
zv::Val assignedScope = ptse::scopeOf(assignResult.raw());
if (UNEXPECTED(assignedScope.isUndef())) return zv::Val();

zv::Val variableFlow = ptse::incDecFlow(child.variableFlow.raw(), valueFlowWrite.raw(), context, var, pt_pih_kind, assignedScope.raw(), storage);
zv::Val variableFlow = ptse::incDecFlow(child.variableFlow.raw(), valueFlowWrite.raw(), context, var, pt_pih_kind, assignedScope.raw(), storage, true);
if (UNEXPECTED(variableFlow.isUndef())) return zv::Val();
zv::Val dependenciesHold;
zval *dependencies = pt_expression_result_dependencies(varResult.raw(), dependenciesHold);
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14 changes: 7 additions & 7 deletions turbo-ext/src/SimpleExprHandlers.h
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Expand Up @@ -132,11 +132,9 @@ inline zv::Val valueFlowContext(zval *context, zval *valueFlowWrite)
return pt_expression_context_enter_value_flow(deep.raw(), valueFlowWrite, false);
}

/* VariableFlow::sequence($varResult->getVariableFlow(), $valueFlowWrite !==
* null && $context->isValueConsumed() ? VariableFlow::inputs($valueFlowWrite->getId(),
* $context->getValueFlowTarget() !== null ? $context->getValueFlowTarget()->getId() : null)
* : null, VariableFlowBuilder::targetWrite($var, $kind, $assignedScope, $storage)) */
inline zv::Val incDecFlow(zval *varFlow, zval *valueFlowWrite, zval *context, zval *var, zend_long kind, zval *assignedScope, zval *storage)
/* Post-inc/dec consumes the inputs of the write; pre-inc/dec consumes the
* newly written value, so its target read must follow the target write. */
inline zv::Val incDecFlow(zval *varFlow, zval *valueFlowWrite, zval *context, zval *var, zend_long kind, zval *assignedScope, zval *storage, bool readsNewValue = false)
{
zv::Val inputsFlow = zv::Val::null();
if (Z_TYPE_P(valueFlowWrite) != IS_NULL) {
Expand All @@ -154,13 +152,15 @@ inline zv::Val incDecFlow(zval *varFlow, zval *valueFlowWrite, zval *context, zv
targetId = variableWriteId(target.raw());
if (UNEXPECTED(targetId.isUndef())) return zv::Val();
}
inputsFlow = pt_variable_flow_inputs(zval_get_long(writeId.raw()), targetId.raw());
inputsFlow = readsNewValue
? pt_variable_flow_builder_target_read(var, storage, true, targetId.raw())
: pt_variable_flow_inputs(zval_get_long(writeId.raw()), targetId.raw());
if (UNEXPECTED(inputsFlow.isUndef())) return zv::Val();
}
}
zv::Val targetWriteFlow = pt_variable_flow_builder_target_write(var, kind, assignedScope, storage, NULL);
if (UNEXPECTED(targetWriteFlow.isUndef())) return zv::Val();
zv::Args flows{varFlow, inputsFlow.raw(), targetWriteFlow.raw()};
zv::Args flows{varFlow, readsNewValue ? targetWriteFlow.raw() : inputsFlow.raw(), readsNewValue ? inputsFlow.raw() : targetWriteFlow.raw()};
return pt_variable_flow_sequence(3, flows);
}

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