CodeQL library for C/C++
codeql/cpp-all 1.1.0 (changelog, source)

Member predicate PhiInstruction::getAnInput

Gets an instruction that defines the input to one of the operands of this instruction. It’s possible for more than one operand to have the same defining instruction, so this predicate will have the same number of results as getAnInputOperand() or fewer.

Instruction getAnInput()