HHVM 4.155 is released! This release marks the end of support of 4.148; 4.149 - 4.154 remain supported, as does the 4.128 LTS release.

Highlights

• Added HHVM_COMPILER_TIMESTAMP constant to hhi for type checker, which contains the timestamp to build hhvm.
• Added narrower or pure capability declarations to the following builtin APIs:
  • create_opaque_value and unwrap_opaque_value
  • HH\Lib\Math\to_base
  • hash_*
• Permitted generic methods to override their own instantiations. e.g. function foo(int):int in a super class can be overridden as function foo<T>(T):T in a subclass.
• Allowed multiple --single options in hh_client invocations.
• Added a quickfix for missing awaitable type.
• Added hover docs for type aliases and contexts.
• Correctly handle negative and large integers passed to array_fill (See CVE-2022-27809).

Breaking Changes

• Enum class label expressions now requires defaults capability.
• Fixed an unsoundness allowing arithmetic expressions to be typed as int when one of the operands is an unsolved type.
• Moved all PERDIR ini settings to be SYSTEM settings.
• Deleted the runtime option Eval.EnableZendIniCompat.
• Removed the following options from HPHPc:
  • --force
  • --gen-stats
  • --sync-dir
  • --target
  • --program
  • --args
  • --include-path
  • --branch
  • --revision
  • --config-dir
• HPHPc now requires a --output-dir argument:
• Fixed an unsoundness due to type parameter name clash. e.g. given interface A<T> { function f<T1>(T $a): T1; }, if A is implemented in a class introducing type parameter name clash as class B<T1> extends A<T1> { function f<T1>(T1 $a): T1 { return $a; } }, when upcasting B to A, /*A<int>*/ $a = new B<int>();, it would allow for arbitrary type convention like Str\length($a->f(1));.