From 24d512c30fe1aa1760516b7043dbbdcd18d21236 Mon Sep 17 00:00:00 2001 From: pca006132 Date: Mon, 4 Jan 2021 14:54:57 +0800 Subject: [PATCH] added expression_inference --- nac3core/src/expression_inference.rs | 370 +++++++++++++++++++++++++++ nac3core/src/lib.rs | 1 + 2 files changed, 371 insertions(+) create mode 100644 nac3core/src/expression_inference.rs diff --git a/nac3core/src/expression_inference.rs b/nac3core/src/expression_inference.rs new file mode 100644 index 00000000..79caffe2 --- /dev/null +++ b/nac3core/src/expression_inference.rs @@ -0,0 +1,370 @@ +use crate::context::InferenceContext; +use crate::inference_core::resolve_call; +use crate::magic_methods::*; +use crate::primitives::*; +use crate::typedef::{Type, TypeEnum::*}; +use rustpython_parser::ast::{ + Comparison, Comprehension, ComprehensionKind, Expression, ExpressionType, Operator, + UnaryOperator, +}; +use std::convert::TryInto; + +type ParserResult = Result, String>; + +pub fn infer_expr<'b: 'a, 'a>( + ctx: &mut InferenceContext<'a>, + expr: &'b Expression, +) -> ParserResult { + match &expr.node { + ExpressionType::Number { value } => infer_constant(ctx, value), + ExpressionType::Identifier { name } => infer_identifier(ctx, name), + ExpressionType::List { elements } => infer_list(ctx, elements), + ExpressionType::Tuple { elements } => infer_tuple(ctx, elements), + ExpressionType::Attribute { value, name } => infer_attribute(ctx, value, name), + ExpressionType::BoolOp { values, .. } => infer_bool_ops(ctx, values), + ExpressionType::Binop { a, b, op } => infer_bin_ops(ctx, op, a, b), + ExpressionType::Unop { op, a } => infer_unary_ops(ctx, op, a), + ExpressionType::Compare { vals, ops } => infer_compare(ctx, vals, ops), + ExpressionType::Call { + args, + function, + keywords, + } => { + if !keywords.is_empty() { + Err("keyword is not supported".into()) + } else { + infer_call(ctx, &args, &function) + } + } + ExpressionType::Subscript { a, b } => infer_subscript(ctx, a, b), + ExpressionType::IfExpression { test, body, orelse } => { + infer_if_expr(ctx, &test, &body, orelse) + } + ExpressionType::Comprehension { kind, generators } => match kind.as_ref() { + ComprehensionKind::List { element } => { + if generators.len() == 1 { + infer_list_comprehension(ctx, element, &generators[0]) + } else { + Err("only 1 generator statement is supported".into()) + } + } + _ => Err("only list comprehension is supported".into()), + }, + ExpressionType::True | ExpressionType::False => Ok(Some(ctx.get_primitive(BOOL_TYPE))), + _ => Err("not supported".into()), + } +} + +fn infer_constant( + ctx: &mut InferenceContext, + value: &rustpython_parser::ast::Number, +) -> ParserResult { + use rustpython_parser::ast::Number; + match value { + Number::Integer { value } => { + let int32: Result = value.try_into(); + if int32.is_ok() { + Ok(Some(ctx.get_primitive(INT32_TYPE))) + } else { + let int64: Result = value.try_into(); + if int64.is_ok() { + Ok(Some(ctx.get_primitive(INT64_TYPE))) + } else { + Err("integer out of range".into()) + } + } + } + Number::Float { .. } => Ok(Some(ctx.get_primitive(FLOAT_TYPE))), + _ => Err("not supported".into()), + } +} + +fn infer_identifier(ctx: &mut InferenceContext, name: &str) -> ParserResult { + Ok(Some(ctx.resolve(name)?)) +} + +fn infer_list<'b: 'a, 'a>( + ctx: &mut InferenceContext<'a>, + elements: &'b [Expression], +) -> ParserResult { + if elements.is_empty() { + return Ok(Some(ParametricType(LIST_TYPE, vec![BotType.into()]).into())); + } + + let mut types = elements.iter().map(|v| infer_expr(ctx, v)); + + let head = types.next().unwrap()?; + if head.is_none() { + return Err("list elements must have some type".into()); + } + for v in types { + if v? != head { + return Err("inhomogeneous list is not allowed".into()); + } + } + Ok(Some(ParametricType(LIST_TYPE, vec![head.unwrap()]).into())) +} + +fn infer_tuple<'b: 'a, 'a>( + ctx: &mut InferenceContext<'a>, + elements: &'b [Expression], +) -> ParserResult { + let types: Result>, String> = + elements.iter().map(|v| infer_expr(ctx, v)).collect(); + if let Some(t) = types? { + Ok(Some(ParametricType(TUPLE_TYPE, t).into())) + } else { + Err("tuple elements must have some type".into()) + } +} + +fn infer_attribute<'a>( + ctx: &mut InferenceContext<'a>, + value: &'a Expression, + name: &str, +) -> ParserResult { + let value = infer_expr(ctx, value)?.ok_or_else(|| "no value".to_string())?; + if let TypeVariable(id) = value.as_ref() { + let v = ctx.get_variable_def(*id); + if v.bound.is_empty() { + return Err("no fields on unbounded type variable".into()); + } + let ty = v.bound[0].get_base(ctx).and_then(|v| v.fields.get(name)); + if ty.is_none() { + return Err("unknown field".into()); + } + for x in v.bound[1..].iter() { + let ty1 = x.get_base(ctx).and_then(|v| v.fields.get(name)); + if ty1 != ty { + return Err("unknown field (type mismatch between variants)".into()); + } + } + return Ok(Some(ty.unwrap().clone())); + } + + match value.get_base(ctx) { + Some(b) => match b.fields.get(name) { + Some(t) => Ok(Some(t.clone())), + None => Err("no such field".into()), + }, + None => Err("this object has no fields".into()), + } +} + +fn infer_bool_ops<'a>(ctx: &mut InferenceContext<'a>, values: &'a [Expression]) -> ParserResult { + assert_eq!(values.len(), 2); + let left = infer_expr(ctx, &values[0])?.ok_or_else(|| "no value".to_string())?; + let right = infer_expr(ctx, &values[1])?.ok_or_else(|| "no value".to_string())?; + + let b = ctx.get_primitive(BOOL_TYPE); + if left == b && right == b { + Ok(Some(b)) + } else { + Err("bool operands must be bool".into()) + } +} + +fn infer_bin_ops<'b: 'a, 'a>( + ctx: &mut InferenceContext<'a>, + op: &Operator, + left: &'b Expression, + right: &'b Expression, +) -> ParserResult { + let left = infer_expr(ctx, left)?.ok_or_else(|| "no value".to_string())?; + let right = infer_expr(ctx, right)?.ok_or_else(|| "no value".to_string())?; + let fun = binop_name(op); + resolve_call(ctx, Some(left), fun, &[right]) +} + +fn infer_unary_ops<'b: 'a, 'a>( + ctx: &mut InferenceContext<'a>, + op: &UnaryOperator, + obj: &'b Expression, +) -> ParserResult { + let ty = infer_expr(ctx, obj)?.ok_or_else(|| "no value".to_string())?; + if let UnaryOperator::Not = op { + if ty == ctx.get_primitive(BOOL_TYPE) { + Ok(Some(ty)) + } else { + Err("logical not must be applied to bool".into()) + } + } else { + resolve_call(ctx, Some(ty), unaryop_name(op), &[]) + } +} + +fn infer_compare<'b: 'a, 'a>( + ctx: &mut InferenceContext<'a>, + vals: &'b [Expression], + ops: &'b [Comparison], +) -> ParserResult { + let types: Result>, _> = vals.iter().map(|v| infer_expr(ctx, v)).collect(); + let types = types?; + if types.is_none() { + return Err("comparison operands must have type".into()); + } + let types = types.unwrap(); + let boolean = ctx.get_primitive(BOOL_TYPE); + let left = &types[..types.len() - 1]; + let right = &types[1..]; + + for ((a, b), op) in left.iter().zip(right.iter()).zip(ops.iter()) { + let fun = comparison_name(op).ok_or_else(|| "unsupported comparison".to_string())?; + let ty = resolve_call(ctx, Some(a.clone()), fun, &[b.clone()])?; + if ty.is_none() || ty.unwrap() != boolean { + return Err("comparison result must be boolean".into()); + } + } + Ok(Some(boolean)) +} + +fn infer_call<'b: 'a, 'a>( + ctx: &mut InferenceContext<'a>, + args: &'b [Expression], + function: &'b Expression, +) -> ParserResult { + let types: Result>, _> = args.iter().map(|v| infer_expr(ctx, v)).collect(); + let types = types?; + if types.is_none() { + return Err("function params must have type".into()); + } + + let (obj, fun) = match &function.node { + ExpressionType::Identifier { name } => (None, name), + ExpressionType::Attribute { value, name } => ( + Some(infer_expr(ctx, &value)?.ok_or_else(|| "no value".to_string())?), + name, + ), + _ => return Err("not supported".into()), + }; + resolve_call(ctx, obj, fun.as_str(), &types.unwrap()) +} + +fn infer_subscript<'b: 'a, 'a>( + ctx: &mut InferenceContext<'a>, + a: &'b Expression, + b: &'b Expression, +) -> ParserResult { + let a = infer_expr(ctx, a)?.ok_or_else(|| "no value".to_string())?; + let t = if let ParametricType(LIST_TYPE, ls) = a.as_ref() { + ls[0].clone() + } else { + return Err("subscript is not supported for types other than list".into()); + }; + + match &b.node { + ExpressionType::Slice { elements } => { + let int32 = ctx.get_primitive(INT32_TYPE); + let types: Result>, _> = elements + .iter() + .map(|v| { + if let ExpressionType::None = v.node { + Ok(Some(int32.clone())) + } else { + infer_expr(ctx, v) + } + }) + .collect(); + let types = types?.ok_or_else(|| "slice must have type".to_string())?; + if types.iter().all(|v| v == &int32) { + Ok(Some(a)) + } else { + Err("slice must be int32 type".into()) + } + } + _ => { + let b = infer_expr(ctx, b)?.ok_or_else(|| "no value".to_string())?; + if b == ctx.get_primitive(INT32_TYPE) { + Ok(Some(t)) + } else { + Err("index must be either slice or int32".into()) + } + } + } +} + +fn infer_if_expr<'b: 'a, 'a>( + ctx: &mut InferenceContext<'a>, + test: &'b Expression, + body: &'b Expression, + orelse: &'b Expression, +) -> ParserResult { + let test = infer_expr(ctx, test)?.ok_or_else(|| "no value".to_string())?; + if test != ctx.get_primitive(BOOL_TYPE) { + return Err("test should be bool".into()); + } + + let body = infer_expr(ctx, body)?; + let orelse = infer_expr(ctx, orelse)?; + if body.as_ref() == orelse.as_ref() { + Ok(body) + } else { + Err("divergent type".into()) + } +} + +fn infer_simple_binding<'a: 'b, 'b>( + ctx: &mut InferenceContext<'b>, + name: &'a Expression, + ty: Type, +) -> Result<(), String> { + match &name.node { + ExpressionType::Identifier { name } => { + if name == "_" { + Ok(()) + } else if ctx.defined(name.as_str()) { + Err("duplicated naming".into()) + } else { + ctx.assign(name.as_str(), ty)?; + Ok(()) + } + } + ExpressionType::Tuple { elements } => { + if let ParametricType(TUPLE_TYPE, ls) = ty.as_ref() { + if elements.len() == ls.len() { + for (a, b) in elements.iter().zip(ls.iter()) { + infer_simple_binding(ctx, a, b.clone())?; + } + Ok(()) + } else { + Err("different length".into()) + } + } else { + Err("not supported".into()) + } + } + _ => Err("not supported".into()), + } +} + +fn infer_list_comprehension<'b: 'a, 'a>( + ctx: &mut InferenceContext<'a>, + element: &'b Expression, + comprehension: &'b Comprehension, +) -> ParserResult { + if comprehension.is_async { + return Err("async is not supported".into()); + } + + let iter = infer_expr(ctx, &comprehension.iter)?.ok_or_else(|| "no value".to_string())?; + if let ParametricType(LIST_TYPE, ls) = iter.as_ref() { + ctx.with_scope(|ctx| { + infer_simple_binding(ctx, &comprehension.target, ls[0].clone())?; + + let boolean = ctx.get_primitive(BOOL_TYPE); + for test in comprehension.ifs.iter() { + let result = + infer_expr(ctx, test)?.ok_or_else(|| "no value in test".to_string())?; + if result != boolean { + return Err("test must be bool".into()); + } + } + let result = infer_expr(ctx, element)?.ok_or_else(|| "no value")?; + Ok(Some(ParametricType(LIST_TYPE, vec![result]).into())) + }) + .1 + } else { + Err("iteration is supported for list only".into()) + } +} + diff --git a/nac3core/src/lib.rs b/nac3core/src/lib.rs index 323dd504..5cc15c3c 100644 --- a/nac3core/src/lib.rs +++ b/nac3core/src/lib.rs @@ -5,6 +5,7 @@ extern crate num_bigint; extern crate inkwell; extern crate rustpython_parser; +pub mod expression_inference; pub mod inference_core; mod magic_methods; pub mod primitives;