451: More type inference for more binary expressions r=flodiebold a=marcusklaas

Implements more of https://github.com/rust-analyzer/rust-analyzer/issues/390. Just works for primitive (numeric) types for now.

Found an issue where `let x: Ty = expr;` doesn't actually propagate the type information unless `Ty` is primitive and numeric. I'll open an issue for this.

Co-authored-by: Marcus Klaas de Vries <mail@marcusklaas.nl>
This commit is contained in:
bors[bot] 2019-01-07 20:05:44 +00:00
commit 812e47785b
7 changed files with 199 additions and 49 deletions

View File

@ -527,9 +527,7 @@ struct InferenceContext<'a, D: HirDatabase> {
return_ty: Ty,
}
// helper function that determines whether a binary operator
// always returns a boolean
fn is_boolean_operator(op: BinaryOp) -> bool {
fn binary_op_return_ty(op: BinaryOp, rhs_ty: Ty) -> Ty {
match op {
BinaryOp::BooleanOr
| BinaryOp::BooleanAnd
@ -537,7 +535,70 @@ fn is_boolean_operator(op: BinaryOp) -> bool {
| BinaryOp::LesserEqualTest
| BinaryOp::GreaterEqualTest
| BinaryOp::LesserTest
| BinaryOp::GreaterTest => true,
| BinaryOp::GreaterTest => Ty::Bool,
BinaryOp::Assignment
| BinaryOp::AddAssign
| BinaryOp::SubAssign
| BinaryOp::DivAssign
| BinaryOp::MulAssign
| BinaryOp::RemAssign
| BinaryOp::ShrAssign
| BinaryOp::ShlAssign
| BinaryOp::BitAndAssign
| BinaryOp::BitOrAssign
| BinaryOp::BitXorAssign => Ty::unit(),
BinaryOp::Addition
| BinaryOp::Subtraction
| BinaryOp::Multiplication
| BinaryOp::Division
| BinaryOp::Remainder
| BinaryOp::LeftShift
| BinaryOp::RightShift
| BinaryOp::BitwiseAnd
| BinaryOp::BitwiseOr
| BinaryOp::BitwiseXor => match rhs_ty {
Ty::Uint(..) | Ty::Int(..) | Ty::Float(..) => rhs_ty,
_ => Ty::Unknown,
},
BinaryOp::RangeRightOpen | BinaryOp::RangeRightClosed => Ty::Unknown,
}
}
fn binary_op_rhs_expectation(op: BinaryOp, lhs_ty: Ty) -> Ty {
match op {
BinaryOp::BooleanAnd | BinaryOp::BooleanOr => Ty::Bool,
BinaryOp::Assignment | BinaryOp::EqualityTest => match lhs_ty {
Ty::Uint(..) | Ty::Int(..) | Ty::Float(..) | Ty::Str | Ty::Char | Ty::Bool => lhs_ty,
_ => Ty::Unknown,
},
BinaryOp::LesserEqualTest
| BinaryOp::GreaterEqualTest
| BinaryOp::LesserTest
| BinaryOp::GreaterTest
| BinaryOp::AddAssign
| BinaryOp::SubAssign
| BinaryOp::DivAssign
| BinaryOp::MulAssign
| BinaryOp::RemAssign
| BinaryOp::ShrAssign
| BinaryOp::ShlAssign
| BinaryOp::BitAndAssign
| BinaryOp::BitOrAssign
| BinaryOp::BitXorAssign
| BinaryOp::Addition
| BinaryOp::Subtraction
| BinaryOp::Multiplication
| BinaryOp::Division
| BinaryOp::Remainder
| BinaryOp::LeftShift
| BinaryOp::RightShift
| BinaryOp::BitwiseAnd
| BinaryOp::BitwiseOr
| BinaryOp::BitwiseXor => match lhs_ty {
Ty::Uint(..) | Ty::Int(..) | Ty::Float(..) => lhs_ty,
_ => Ty::Unknown,
},
_ => Ty::Unknown,
}
}
@ -889,20 +950,20 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
}
Expr::BinaryOp { lhs, rhs, op } => match op {
Some(op) => {
let subtype_expectation = match op {
let lhs_expectation = match op {
BinaryOp::BooleanAnd | BinaryOp::BooleanOr => {
Expectation::has_type(Ty::Bool)
}
_ => Expectation::none(),
};
let _lhs_ty = self.infer_expr(*lhs, &subtype_expectation)?;
let _rhs_ty = self.infer_expr(*rhs, &subtype_expectation)?;
let lhs_ty = self.infer_expr(*lhs, &lhs_expectation)?;
// TODO: find implementation of trait corresponding to operation
// symbol and resolve associated `Output` type
let rhs_expectation = binary_op_rhs_expectation(*op, lhs_ty);
let rhs_ty = self.infer_expr(*rhs, &Expectation::has_type(rhs_expectation))?;
if is_boolean_operator(*op) {
Ty::Bool
} else {
Ty::Unknown
}
// TODO: similar as above, return ty is often associated trait type
binary_op_return_ty(*op, rhs_ty)
}
_ => Ty::Unknown,
},

View File

@ -157,7 +157,7 @@ impl S {
}
#[test]
fn infer_boolean_op() {
fn infer_binary_op() {
check_inference(
r#"
fn f(x: bool) -> i32 {
@ -168,15 +168,18 @@ fn test() {
let x = a && b;
let y = true || false;
let z = x == y;
let h = CONST_1 <= CONST_2;
let minus_forty: isize = -40isize;
let h = minus_forty <= CONST_2;
let c = f(z || y) + 5;
let d = b;
let e = 3i32 && "hello world";
let g = minus_forty ^= i;
let ten: usize = 10;
let ten_is_eleven = ten == some_num;
10 < 3
ten < 3
}
"#,
"boolean_op.txt",
"binary_op.txt",
);
}

View File

@ -0,0 +1,46 @@
[6; 7) 'x': [unknown]
[22; 34) '{ 0i32 }': i32
[28; 32) '0i32': i32
[46; 342) '{ ... < 3 }': bool
[56; 57) 'x': bool
[60; 61) 'a': bool
[60; 66) 'a && b': bool
[65; 66) 'b': bool
[76; 77) 'y': bool
[80; 84) 'true': bool
[80; 93) 'true || false': bool
[88; 93) 'false': bool
[103; 104) 'z': bool
[107; 108) 'x': bool
[107; 113) 'x == y': bool
[112; 113) 'y': bool
[123; 134) 'minus_forty': isize
[144; 152) '-40isize': isize
[145; 152) '40isize': [unknown]
[162; 163) 'h': bool
[166; 177) 'minus_forty': isize
[166; 188) 'minus_...ONST_2': bool
[181; 188) 'CONST_2': isize
[198; 199) 'c': i32
[202; 203) 'f': fn([unknown],) -> i32
[202; 211) 'f(z || y)': i32
[202; 215) 'f(z || y) + 5': i32
[204; 205) 'z': bool
[204; 210) 'z || y': bool
[209; 210) 'y': bool
[214; 215) '5': i32
[225; 226) 'd': [unknown]
[229; 230) 'b': [unknown]
[240; 241) 'g': ()
[244; 255) 'minus_forty': isize
[244; 260) 'minus_...y ^= i': ()
[259; 260) 'i': isize
[270; 273) 'ten': usize
[283; 285) '10': usize
[295; 308) 'ten_is_eleven': bool
[311; 314) 'ten': usize
[311; 326) 'ten == some_num': bool
[318; 326) 'some_num': usize
[333; 336) 'ten': usize
[333; 340) 'ten < 3': bool
[339; 340) '3': usize

View File

@ -1,31 +0,0 @@
[6; 7) 'x': [unknown]
[22; 34) '{ 0i32 }': i32
[28; 32) '0i32': i32
[46; 237) '{ ... < 3 }': bool
[56; 57) 'x': bool
[60; 61) 'a': bool
[60; 66) 'a && b': bool
[65; 66) 'b': bool
[76; 77) 'y': bool
[80; 84) 'true': bool
[80; 93) 'true || false': bool
[88; 93) 'false': bool
[103; 104) 'z': bool
[107; 108) 'x': bool
[107; 113) 'x == y': bool
[112; 113) 'y': bool
[123; 124) 'h': bool
[127; 134) 'CONST_1': [unknown]
[127; 145) 'CONST_...ONST_2': bool
[138; 145) 'CONST_2': [unknown]
[155; 156) 'c': [unknown]
[159; 172) 'f(z || y) + 5': [unknown]
[182; 183) 'd': [unknown]
[186; 187) 'b': [unknown]
[197; 198) 'e': bool
[201; 205) '3i32': bool
[201; 222) '3i32 &...world"': bool
[209; 222) '"hello world"': bool
[229; 231) '10': [unknown]
[229; 235) '10 < 3': bool
[234; 235) '3': [unknown]

View File

@ -504,7 +504,52 @@ pub enum BinOp {
LesserTest,
/// The `>` operator for comparison
GreaterTest,
// TODO: lots of others
/// The `+` operator for addition
Addition,
/// The `*` operator for multiplication
Multiplication,
/// The `-` operator for subtraction
Subtraction,
/// The `/` operator for division
Division,
/// The `%` operator for remainder after division
Remainder,
/// The `<<` operator for left shift
LeftShift,
/// The `>>` operator for right shift
RightShift,
/// The `^` operator for bitwise XOR
BitwiseXor,
/// The `|` operator for bitwise OR
BitwiseOr,
/// The `&` operator for bitwise AND
BitwiseAnd,
/// The `..` operator for right-open ranges
RangeRightOpen,
/// The `..=` operator for right-closed ranges
RangeRightClosed,
/// The `=` operator for assignment
Assignment,
/// The `+=` operator for assignment after additon
AddAssign,
/// The `/=` operator for assignment after division
DivAssign,
/// The `*=` operator for assignment after multiplication
MulAssign,
/// The `%=` operator for assignment after remainders
RemAssign,
/// The `>>=` operator for assignment after shifting right
ShrAssign,
/// The `<<=` operator for assignment after shifting left
ShlAssign,
/// The `-=` operator for assignment after subtraction
SubAssign,
/// The `|=` operator for assignment after bitwise OR
BitOrAssign,
/// The `&=` operator for assignment after bitwise AND
BitAndAssign,
/// The `^=` operator for assignment after bitwise XOR
BitXorAssign,
}
impl<'a> BinExpr<'a> {
@ -519,6 +564,29 @@ impl<'a> BinExpr<'a> {
GTEQ => Some(BinOp::GreaterEqualTest),
L_ANGLE => Some(BinOp::LesserTest),
R_ANGLE => Some(BinOp::GreaterTest),
PLUS => Some(BinOp::Addition),
STAR => Some(BinOp::Multiplication),
MINUS => Some(BinOp::Subtraction),
SLASH => Some(BinOp::Division),
PERCENT => Some(BinOp::Remainder),
SHL => Some(BinOp::LeftShift),
SHR => Some(BinOp::RightShift),
CARET => Some(BinOp::BitwiseXor),
PIPE => Some(BinOp::BitwiseOr),
AMP => Some(BinOp::BitwiseAnd),
DOTDOT => Some(BinOp::RangeRightOpen),
DOTDOTEQ => Some(BinOp::RangeRightClosed),
EQ => Some(BinOp::Assignment),
PLUSEQ => Some(BinOp::AddAssign),
SLASHEQ => Some(BinOp::DivAssign),
STAREQ => Some(BinOp::MulAssign),
PERCENTEQ => Some(BinOp::RemAssign),
SHREQ => Some(BinOp::ShrAssign),
SHLEQ => Some(BinOp::ShlAssign),
MINUSEQ => Some(BinOp::SubAssign),
PIPEEQ => Some(BinOp::BitOrAssign),
AMPEQ => Some(BinOp::BitAndAssign),
CARETEQ => Some(BinOp::BitXorAssign),
_ => None,
})
.next()

View File

@ -49,6 +49,7 @@ Grammar(
["^=", "CARETEQ"],
["/=", "SLASHEQ"],
["*=", "STAREQ"],
["%=", "PERCENTEQ"],
["&&", "AMPAMP"],
["||", "PIPEPIPE"],
["<<", "SHL"],

View File

@ -58,6 +58,7 @@ pub enum SyntaxKind {
CARETEQ,
SLASHEQ,
STAREQ,
PERCENTEQ,
AMPAMP,
PIPEPIPE,
SHL,
@ -319,6 +320,7 @@ impl SyntaxKind {
CARETEQ => &SyntaxInfo { name: "CARETEQ" },
SLASHEQ => &SyntaxInfo { name: "SLASHEQ" },
STAREQ => &SyntaxInfo { name: "STAREQ" },
PERCENTEQ => &SyntaxInfo { name: "PERCENTEQ" },
AMPAMP => &SyntaxInfo { name: "AMPAMP" },
PIPEPIPE => &SyntaxInfo { name: "PIPEPIPE" },
SHL => &SyntaxInfo { name: "SHL" },