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use super::binary::{operand_contains_null, operand_is_non_bitwise, operand_is_non_numeric};
use super::helpers::{extract_simple_var, infer_int_range_arithmetic};
use super::ExpressionAnalyzer;
use crate::flow_state::FlowState;
use mir_issues::{IssueKind, Severity};
use mir_types::{Atomic, Type};
use php_ast::ast::{BinaryOp, UnaryPostfixOp, UnaryPrefixOp};
use php_ast::owned::{UnaryPostfixExpr, UnaryPrefixExpr};
/// Returns true when every member of `ty` is definitively `true` or `bool`
/// (not `false` — that case is reserved for a future FalseOperand kind).
fn operand_is_definitely_bool(ty: &Type) -> bool {
!ty.types.is_empty()
&& !ty.is_mixed()
&& ty
.types
.iter()
.all(|a| matches!(a, Atomic::TTrue | Atomic::TBool))
}
/// Returns true when `ty` is a non-empty literal string (PHP's string++ is deprecated/invalid).
fn operand_is_non_empty_literal_string(ty: &Type) -> bool {
!ty.types.is_empty()
&& !ty.is_mixed()
&& ty.types.iter().all(|a| match a {
Atomic::TLiteralString(s) => !s.is_empty(),
_ => false,
})
}
impl<'a> ExpressionAnalyzer<'a> {
pub(super) fn analyze_unary_prefix(
&mut self,
u: &UnaryPrefixExpr,
ctx: &mut FlowState,
) -> Type {
let operand_ty = self.analyze(&u.operand, ctx);
match u.op {
UnaryPrefixOp::BooleanNot => Type::single(Atomic::TBool),
UnaryPrefixOp::Negate | UnaryPrefixOp::Plus => {
// Same operand check as binary arithmetic's `+`/`-` — an array,
// object, enum case, or non-numeric string throws a real PHP
// `TypeError`, not the "coerce to 0" fallback `negate_type`'s
// catch-all assumes.
if operand_is_non_numeric(&operand_ty) {
self.emit(
IssueKind::InvalidOperand {
op: if u.op == UnaryPrefixOp::Negate {
"-"
} else {
"+"
}
.to_string(),
left: operand_ty.to_string(),
right: String::new(),
},
Severity::Warning,
u.operand.span,
);
}
if u.op == UnaryPrefixOp::Negate {
negate_type(&operand_ty)
} else {
operand_ty
}
}
UnaryPrefixOp::BitwiseNot => {
if operand_is_non_bitwise(&operand_ty) {
self.emit(
IssueKind::InvalidOperand {
op: "~".to_string(),
left: operand_ty.to_string(),
right: String::new(),
},
Severity::Warning,
u.operand.span,
);
} else if operand_contains_null(&operand_ty) {
self.emit(
IssueKind::PossiblyNullOperand {
op: "~".to_string(),
ty: operand_ty.to_string(),
},
Severity::Info,
u.operand.span,
);
}
Type::single(Atomic::TInt)
}
UnaryPrefixOp::PreIncrement | UnaryPrefixOp::PreDecrement => {
// `++`/`--` on a property/array-index-into-property/static
// property is a write, same as `+=` — route it through the
// shared purity/immutability/readonly gate. Reuses
// `check_byref_arg_purity` (originally for by-ref call
// arguments) since it already covers exactly this same set
// of mutation-target shapes; this arm previously only
// special-cased a direct `PropertyAccess` operand, missing
// an array-index-into-property (`$t->counts['x']++`) or a
// static property (`Frozen::$hits++`) entirely.
self.check_byref_arg_purity(&u.operand, ctx, u.operand.span);
// Same operand check as postfix ++/-- — the same PHP warning/
// deprecation fires for both forms, only postfix was flagged.
if operand_is_definitely_bool(&operand_ty)
|| operand_is_non_empty_literal_string(&operand_ty)
{
self.emit(
IssueKind::InvalidOperand {
op: if u.op == UnaryPrefixOp::PreIncrement {
"++"
} else {
"--"
}
.to_string(),
left: operand_ty.to_string(),
right: String::new(),
},
Severity::Warning,
u.operand.span,
);
}
if let Some(var_name) = extract_simple_var(&u.operand) {
let ty = ctx.get_var(&var_name);
let new_ty = if ty.contains(|t| {
matches!(
t,
Atomic::TFloat | Atomic::TIntegralFloat | Atomic::TLiteralFloat(..)
)
}) {
Type::single(Atomic::TFloat)
} else {
let op = if u.op == UnaryPrefixOp::PreIncrement {
BinaryOp::Add
} else {
BinaryOp::Sub
};
let one = Type::single(Atomic::TLiteralInt(1));
infer_int_range_arithmetic(&ty, &one, op)
.unwrap_or_else(|| Type::single(Atomic::TInt))
};
ctx.set_var(&var_name, new_ty.clone());
let (line, col_start) = self.offset_to_line_col(u.operand.span.start);
let (line_end, col_end) = self.offset_to_line_col(u.operand.span.end);
ctx.record_var_location(&var_name, line, col_start, line_end, col_end);
new_ty
} else {
Type::single(Atomic::TInt)
}
}
}
}
pub(super) fn analyze_unary_postfix(
&mut self,
u: &UnaryPostfixExpr,
ctx: &mut FlowState,
) -> Type {
let operand_ty = self.analyze(&u.operand, ctx);
match u.op {
UnaryPostfixOp::PostIncrement | UnaryPostfixOp::PostDecrement => {
let op_str = if u.op == UnaryPostfixOp::PostIncrement {
"++"
} else {
"--"
};
// See the prefix arm's identical comment: reuses
// `check_byref_arg_purity` to cover property,
// array-index-into-property, and static-property operands
// uniformly, not just a direct `PropertyAccess`.
self.check_byref_arg_purity(&u.operand, ctx, u.operand.span);
// Flag increment/decrement on a definitely-bool operand (PHP
// silently no-ops; TFalse reserved for future FalseOperand kind)
// or on a non-empty literal string (deprecated in PHP 8.3+).
if operand_is_definitely_bool(&operand_ty)
|| operand_is_non_empty_literal_string(&operand_ty)
{
self.emit(
IssueKind::InvalidOperand {
op: op_str.to_string(),
left: operand_ty.to_string(),
right: String::new(),
},
Severity::Warning,
u.operand.span,
);
}
if let Some(var_name) = extract_simple_var(&u.operand) {
let new_ty = if operand_ty.contains(|t| {
matches!(
t,
Atomic::TFloat | Atomic::TIntegralFloat | Atomic::TLiteralFloat(..)
)
}) {
Type::single(Atomic::TFloat)
} else {
let op = if u.op == UnaryPostfixOp::PostIncrement {
BinaryOp::Add
} else {
BinaryOp::Sub
};
let one = Type::single(Atomic::TLiteralInt(1));
infer_int_range_arithmetic(&operand_ty, &one, op)
.unwrap_or_else(|| Type::single(Atomic::TInt))
};
ctx.set_var(&var_name, new_ty);
let (line, col_start) = self.offset_to_line_col(u.operand.span.start);
let (line_end, col_end) = self.offset_to_line_col(u.operand.span.end);
ctx.record_var_location(&var_name, line, col_start, line_end, col_end);
}
operand_ty
}
}
}
}
/// Infer the result type of the unary negation operator (`-$x`).
///
/// Propagates literal and range information through negation so that
/// e.g. `-7` gives `int<-7,-7>` rather than bare `int`, and
/// `-positive-int` gives `negative-int`.
fn negate_type(ty: &Type) -> Type {
if ty.is_mixed() {
return Type::mixed();
}
// Safe negation of an optional bound: None (unbounded) stays None; overflow
// (i64::MIN.checked_neg() == None) falls back to None (unbounded).
let neg_bound = |v: Option<i64>| v.and_then(|n| n.checked_neg());
let mut result = Type::empty();
for a in &ty.types {
let atom = match a {
Atomic::TLiteralInt(n) => {
if let Some(neg) = n.checked_neg() {
Atomic::TLiteralInt(neg)
} else {
// i64::MIN — falls back to bare int.
Atomic::TInt
}
}
Atomic::TPositiveInt => Atomic::TNegativeInt,
Atomic::TNegativeInt => Atomic::TPositiveInt,
// non-negative-int negated is int<-∞, 0> (no named type — use TIntRange).
Atomic::TNonNegativeInt => Atomic::TIntRange {
min: None,
max: Some(0),
},
Atomic::TInt => Atomic::TInt,
Atomic::TIntRange { min, max } => {
let new_min = neg_bound(*max);
let new_max = neg_bound(*min);
match (new_min, new_max) {
(Some(1), None) => Atomic::TPositiveInt,
(Some(0), None) => Atomic::TNonNegativeInt,
(None, Some(-1)) => Atomic::TNegativeInt,
(None, None) => Atomic::TInt,
_ => Atomic::TIntRange {
min: new_min,
max: new_max,
},
}
}
Atomic::TFloat | Atomic::TIntegralFloat | Atomic::TLiteralFloat(..) => Atomic::TFloat,
_ => {
// Non-numeric operands: fallback to int (PHP coerces to 0 then negates).
if ty.contains(|t| t.is_int()) {
Atomic::TInt
} else {
Atomic::TFloat
}
}
};
result.add_type(atom);
}
result
}