Improvements:

• Performance optimizations for template type substitution and FQSEN caching (#5417, #5418)
  • Early-exit checks in Method::cloneWithTemplateParameterTypeMap to avoid unnecessary cloning
  • Optimized CallableParamPlugin for functions with no parameters
  • Two-level cache for FullyQualifiedClassElement::make using object IDs
• Allow Symfony 8.0 compatibility (#5401)
• Fixed composer-patches package location for PHP 8.5 compatibility (#5387)

Nov 20 2025, Phan 6.0.0-beta

Breaking changes:

• Requires PHP 8.1+ to run and minimum target version is now PHP 8.1
• Requires php-ast 1.1.3+ for PHP 8.4+ analysis (AST version 110/120 support)
• The -i CLI option is now an alias of --incremental instead of --ignore-undeclared
• Renamed the PhanPluginCanUsePHP71Void issue to PhanPluginCanUseVoidReturnType
• Dropped the allow_method_param_type_widening config option (contravariance is now always allowed)
• Dropped the backward_compatibility_checks config option, along with its respective --backward-compatibility-checks and -b CLI flags

New features (Analysis):

• Large literal arrays are now summarized to representative samples during parsing, significantly reducing peak memory when analyzing massive datasets.
  • Default limits can be tuned via the new config options ast_trim_max_elements_per_level (default 256) and ast_trim_max_total_elements (default 512).
• Union types are automatically clamped once they exceed max_union_type_set_size (default 1024), preventing runaway growth from deeply nested array merges while keeping type inference useful.
• These trim/clamp thresholds are also exposed as CLI flags (--ast-trim-max-elements-per-level, --ast-trim-max-total-elements, --max-union-type-set-size) for easy experimentation without editing config files.
• Detect implicit float-to-int conversion in modulo operator (deprecated in PHP 8.1)
  • New issue type: PhanTypeInvalidModuloOperand
  • Warns when float types are used with the modulo (%) operator
• Improved analysis of intersection types with unknown classes (#4431)
  • When an intersection type includes both known and unknown classes, Phan now analyzes the known types
  • Method calls and property access are checked against known classes in the intersection
  • Enables type checking even when some dependencies are missing or stubs are incomplete
  • Also improves analysis of catch blocks with mixed known/unknown exception types
• Full support for PHP 8.5 features:
  • #[NoDiscard] attribute support with detection of ignored return values (PhanNoDiscardReturnValueIgnored)
  • #[Override] attribute extended to properties (in addition to methods)
  • Pipe operator (|>) with full type inference through piped call chains
  • (void) cast support for suppressing NoDiscard warnings
  • Updated function signatures for PHP 8.5 standard library changes
• Full support for PHP 8.4 property hooks
  • Parse and validate property hook syntax (get/set hooks)
  • Parameter type checking for set hook parameters
  • Validation of hooks with default values (PhanPropertyHookWithDefaultValue)
  • Validation of readonly properties with set hooks (PhanReadonlyPropertyHasSetHook)
  • Return type compatibility validation (PhanPropertyHookIncompatibleReturnType)
  • Parameter type compatibility validation (PhanPropertyHookIncompatibleParamType)
  • Final hook override detection (PhanPropertyHookFinalOverride)
• Support for PHP 8.4 #[Deprecated] attribute
  • Recognize #[Deprecated] attribute on functions, methods, and class constants
  • Works alongside existing @deprecated PHPDoc comment support
  • Emits PhanDeprecatedFunction and PhanDeprecatedClassConstant warnings when deprecated elements are used
• Support for new PHP 8.4 functions and methods
  • DateTime::createFromTimestamp() / DateTimeImmutable::createFromTimestamp()
  • DOMXPath::registerPHPFunctionNS()
  • All new PHP 8.4 functions: array_find, array_find_key, array_any, array_all, mb_trim, mb_ltrim, mb_rtrim, mb_ucfirst, mb_lcfirst, and more
• Full support for "new without parentheses" syntax (e.g., new MyClass()->method())
  • Type inference works correctly across method chains
  • Property and array access supported
• Multiline doc comments for @param, @var, and @return
  • Doc comment parsing now normalizes multi-line @param, @var, and @return annotations before analysis, allowing nested array/generic syntax to be laid out across several lines without being misinterpreted.
  • Extended multiline support to Phan-specific annotations: @phan-param, @phan-var, @phan-return, @phan-real-return, @phan-property*, @phan-assert, @phan-type, @phan-implements, @phan-extends, @phan-inherits, @phan-use (#4252)
  • PHPDocRedundantPlugin now flags redundant @var annotations on typed properties, matching its existing coverage for functions and methods.
• PreferNamespaceUsePlugin now handles union types
• Improved generics support (#5182)
  • Enhanced template type handling and generic type inference
  • Better resolution of generic types in complex scenarios
• Full support for PHP 8.3 typed class constants (#5140, #5128)
  • Inheritance checking and validation
  • New issue types: PhanTypeMismatchDeclaredConstant, PhanTypeMismatchDeclaredConstantNever, PhanConstantTypeMismatchInheritance
  • Proper type narrowing for class constants in conditions (#5127)
• Literal type exclusion in !in_array() checks (#5185)
  • Type narrowing when checking values against literal arrays (up to 50 elements)
  • Improves precision when checking against known sets of values
• Reference assignment literal type erasure (#5197, #4354)
  • Variables involved in reference assignments ($var2 =& $var1) now have their literal types erased
  • Prevents incorrect literal type tracking when variables are aliased
  • Applies to both sides of reference assignment and persists across subsequent assignments
• Enhanced type inference improvements:
  • array_filter() recognizes null-stripping callbacks and keeps element types non-null (#5100)
  • array_chunk() return type inference based on preserve_keys parameter (#5165)
  • constant() return type inference from Phan's constant table for non-dynamic constants (#5157)
  • stdClass property inference from array shape casts (#5151)
  • Better static return type resolution preserving intersection types and generics (#5126)
  • Improved foreach iterator type inference honoring explicit iterator generics (#5108)
  • Conditional type refinement after array field checks (#5179)
  • Static properties in conditional expressions (#5194)
• New detection capabilities:
  • UncoveredEnumCasesInMatchPlugin (#5164): Detects when match expressions with enum conditions don't cover all enum cases
  • Duplicate static variable detection (#5176): New PhanDuplicateStaticVariable issue (fatal error in PHP 8.3+)
  • Multiple readonly property assignment (#5175): New PhanAccessReadOnlyPropertyMultipleTimes issue
  • Redundant boolean type combinations (#5174): Warns on redundant type combinations
  • Trait constant compatibility (#5119): New PhanIncompatibleCompositionConstant for conflicting trait constants
  • Interface traits and readonly classes (#5118): Warns when interfaces use traits or readonly classes use non-readonly trait properties
  • Improved unused variable detection (#5093): Catches more cases with compound assignment operators (+=, -=, etc.)
  • Redundant property comments (#5107): Warns on redundant docblocks on typed properties

New features (CLI):

• Git-style config discovery (#5092):
  • Searches parent directories for .phan/config.php
  • Filters output when running from subdirectories
  • New --subdirectory-only flag for analyzing specific modules with better performance
• -n/--no-config-file implicitly limits analysis to just the files provided on the command line (e.g. phan -n test1.php test2.php) avoiding analysis of the rest of the project when you only want quick ad-hoc checks.
• Added support for incremental analysis, where only changed files and their dependents will be analyzed on subsequent runs. Significantly speeds up re-analysis.
  • Add the --incremental / -i option that enables incremental analysis.
  • Add the --force-full-analysis flag to force a full re-analysis of all files, ignoring the incremental analysis manifest.
  • Add the --no-incremental / -N option that disables incremental analysis (useful if it was enabled in config.php).

Performance improvements:

• phan_helpers C extension integration (#5096):
  • Optional C extension for 2-3x faster AST hashing and type deduplication
  • Overall analysis speedup: 5-15% for large projects
  • Automatically detected and used when available
• Internal PHP stub definitions are now cached between CodeBase instances, so repeated test runs and daemon/server reloads reuse the previously parsed classes/functions without reparsing dozens of stub files on every initialization.
• Conditional visitor optimization (#5186):
  • Skip visitor creation for ~60-70% of if statements (those without else/elseif)
  • Reduces memory usage and improves analysis speed
• Incremental analysis support (see CLI features above)
• Subdirectory-only mode for faster focused analysis

New features (Tools):

• Add tool/add_suppressions.php to assist in adding @suppress or @phan-suppress annotations to files
  • Useful for batch suppressing specific issue types across the codebase
  • See tool/SuppressionsToolImplementation.md for technical details

Bug fixes:

Type Inference & Analysis:

• Fixed too strict type inference after !empty() condition on arrays (#5295)
• Fixed union types containing both known objects and mixed being checked too strictly (#5292)
• Fixed PhanAccessReadOnlyPropertyMultipleTimes failing to account for mutually exclusive branches (#5285)
• Fixed declare blocks causing Phan to lose track of declared variables (#5284)
• Fixed conditionals causing wrong type inference for static properties (#5283)
• Fixed too strict PhanTemplateTypeConstraintViolation when type can't be resolved (#5282)
• Fixed Phan using unrelated array elements when inferring types (#5281)
• Fixed array shape type inference for is_object and !is_array checks with mixed types (#5277)
• Fixed static property type narrowing with type-check functions like is_null() and !is_null() (#5277)
• Fixed type accumulation for interface-typed properties ensuring method calls are validated against interface contract (#5300)
• Fixed spurious PhanPossiblyUndeclaredVariable with function calls and following usage (#5269)
• Fixed PhanTypeMismatchGeneratorYieldKey false positive when yield has no key (#5258)
• Fixed PhanAccessOwnConstructor incorrectly warning on valid usage of self::__construct (#5257)
• Fixed unnecessary array key aliasing in type narrowing when assignment happens in foreach iteration (#5255)
• Fixed array unions containing mixed types being checked too strictly for array offsets (#5299)
• Fixed condition-based type narrowing using outdated context when variable is modified in conditionals (#5301)
• Fixed isset() and empty() warning on undefined properties (now only warns on direct access and unset) (#5273)
• Fixed property type narrowing scope leaking into unrelated code paths (#5249)
• Fixed ArrayAccess type checking not validating offsetGet signature (#5251)
• Fixed DNF type false positive when using null defaults (#5252)
• Fixed array_combine signature being too strict for null values (#5219)
• Improved type inference for get_class() to return more specific class-string types (#5274)
• Improved handling of getIterator() returning Iterator with explicit generics (#5108)
• Traits can now declare @require-extends / @require-implements (and their Psalm aliases) to ensure consuming classes satisfy those requirements
• Fixed PhanPossiblyInfiniteRecursionSameParams false positive for instance methods that guard recursion with property state (#5371)
• Fixed PhanTypeMismatchDeclaredConstant false positives for enum cases whose values are strings/ints (#5378)
• Improved parameter and property default type representation in error messages (#5271)

Tooling:

• Baselines generated with --save-baseline now store suppressions per symbol (class/method/function) instead of line numbers and normalize anonymous class/closure names, so suppressions remain stable when code moves or hashes change (#5381/#5383)

Plugins:

• Fixed UnusedSuppressionPlugin incorrectly flagging magic method suppressions in class doc comments as unused (#5304)
• Added missing ANSI color mappings for terminal output (#5294)
• Improved confusing PhanSuspiciousValueComparison message when all literal possibilities exhausted (#5276)
• Fixed issue message for PhanCommentAbstractOnInheritance (#5265)

Other Fixes:

• Fixed nested closure scope tracking bug (#5291)
• Fixed multiline PHPDoc comment parsing issues (#5293)
• Fixed private property static/non-static mismatch detection in traits (#5247)
• Fixed internal stubs not being included in releases (#5244)
• Fixed nullsafe property access: No more strict object checking false positives with ?-> (#5112)
• Fixed trait method multi-level inheritance: Track trait methods through multiple inheritance levels (#5120)
• Fixed DNS aliases: Corrected reversed DNS aliases (#5170)
• Fixed private final constructor: Don't warn on private final constructors (exempted in PHP 8.0+) (#5169)
• Fixed float-to-int in modulo: Detect implicit float-to-int conversion in % operator (#5189)
• Fixed sibling type compatibility: Assignment visitor type checking now works correctly (#5168)
• Fixed dynamic array offset constants: Skip premature constant resolution for define() (#5156)
• Fixed unary operator type aggregation: Corrected numeric fallback ordering bug (#5146)
• Fixed xml_parser_create signature: Corrected incorrect signature (#5139)
• Fixed crash with intersection types: No more EmptyFQSENException with --analyze-twice (#5086)
• Fixed class constant regression: Corrected typed constant false positives after #5128 (#5133)
• Fixed intersection types with unknown classes: Proper method resolution when intersection contains both known and unknown classes (#5190)
• Fixed template type compatibility: No more false positive PhanTypeMismatchDeclaredReturn with template types (#5181)
• Fixed readonly property access: No more false positives with isset() on readonly properties in @phan-side-effect-free classes (#5180)
• Fixed switch fall-through variable tracking: Variable definitions now flow correctly through fall-through cases (#5155)
• Fixed try/catch variable scope: Variable definitions in try blocks with finally clauses now track correctly (#5152, #5131)
• Fixed global variable type pollution in daemon mode: Incremental re-analysis no longer pollutes global variable types (#5183)
• Fixed ternary in function arguments: Proper type narrowing for conditional expressions in arguments (#5166)
• Fixed empty array vs non-empty union: Re-checks union arguments mixing empty and non-empty arrays (#5115)
• Fixed array map callback analysis: No more false positive PhanParamTooFewUnpack with array_map (#5114)
• Fixed static call on trait properties: No more false positives after instanceof checks (#5111)
• Fixed never return type inheritance: Proper detection of inherited never methods via parent::/static:: (#5109)
• Fixed nested array shape field refinement: Suppressed property mismatch warnings when refining nested fields (#5106)
• Fixed enums as class constants: Allow enum types as class constant values (#5103)
• Fixed SID constant handling: Special-case handling for dynamically defined SID constant (#5150)
• Fixed reference assignment literal type erasure: Variables involved in reference assignments now correctly erase literal types to prevent false positives (#5197)

PHPDoc & Attributes:

• Fixed @deprecated detection for callable parameters: Emit PhanDeprecatedFunction when deprecated functions are passed as callable string arguments (#4858)
• Fixed @phan-suppress on class constants: Suppression annotations are no longer ignored (#5188)
• Fixed @phan-mandatory-param inheritance: Inherit annotation from interface methods (#5116)
• Fixed @phan-pure inheritance: Exclude __call and __callStatic from automatic inheritance (#5124)
• Fixed internal method purity: ArrayObject->count() now inherits pure flag from Countable (#5122)
• Fixed PHPDoc type inheritance: Proper inheritance of parameter types from interfaces (#5117)

Plugin Fixes:

• Fixed MoreSpecificElementTypePlugin: No more false positives with array{}|non-empty-array<K,V> (#5187)
• Fixed UnknownElementTypePlugin: No more false positives on inherited methods (#5177)
• Fixed RedundantConditionVisitor: No more false positives with static property empty() checks (#5148)
• Fixed CompactPlugin: Added check for possibly undefined variables (#5167)
• Fixed PHPDocRedundantPlugin: Added auto-fixer for redundant property comments (#5178)

Loop & Control Flow:

• Fixed possibly infinite loop detection: No more false positives when loop condition uses array count (#5153)
• Fixed !isset() variable tracking: Possibly-undefined flag preservation now works correctly (#5172)
• Fixed redundant condition after empty(): Proper static property handling (#5148)

AST Compatibility:

• Fixed AST version 110/120 compatibility for PHP 8.4
  • Updated TolerantASTConverter to support AST version 120
  • Fixed AST structural changes: closure 'name' field removal, parameter 'hooks' field addition, property 'hooks' field addition
  • Fixed clone being incorrectly treated as a function call in AST version 110+ (it's now AST_CALL instead of AST_CLONE)