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use itertools::Itertools;
use nom::{
branch::alt,
bytes::complete::tag,
character::complete::char,
sequence::{self, delimited},
IResult,
};
use proc_macro2::{Ident, Span};
use rem_utils::annotation::Annotations;
use rem_utils::labelling::Label;
use syn::{visit_mut::VisitMut, Expr, ExprAssign, FnArg, Stmt, Type};
/// Aliasing Constraints
#[derive(Clone, Debug, PartialEq, Eq, Hash)]
pub enum AliasConstraints {
Ref(Label),
Alias(Label, Label),
Assign(Label, Label),
}
impl std::fmt::Display for AliasConstraints {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
match self {
AliasConstraints::Ref(r) => write!(f, "ref({})", r),
AliasConstraints::Alias(l, r) => write!(f, "alias({}, {})", l, r),
AliasConstraints::Assign(l, r) => write!(f, "assign({}, {})", l, r),
}
}
}
#[allow(suspicious_double_ref_op)]
impl crate::LocalConstraint for AliasConstraints {
const CHR_RULES: &'static str = include_str!("constraint_rules/alias_constraint_rules.pl");
fn parse(s: &str) -> nom::IResult<&str, Self> {
use rem_utils::parser::{label, ws};
fn ref_(s: &str) -> IResult<&str, AliasConstraints> {
let (s, _) = tag("ref")(s)?;
let (s, l1) = delimited(char('('), label, char(')'))(s)?;
Ok((s, AliasConstraints::Ref(l1)))
}
fn alias(s: &str) -> IResult<&str, AliasConstraints> {
let (s, _) = tag("alias")(s)?;
let (s, (l1, l2)) = delimited(
char('('),
sequence::separated_pair(label, ws(char(',')), label),
char(')'),
)(s)?;
Ok((s, AliasConstraints::Alias(l1, l2)))
}
fn assign(s: &str) -> IResult<&str, AliasConstraints> {
let (s, _) = tag("assign")(s)?;
let (s, (l1, l2)) = delimited(
char('('),
sequence::separated_pair(label, ws(char(',')), label),
char(')'),
)(s)?;
Ok((s, AliasConstraints::Assign(l1, l2)))
}
alt((ref_, alias, assign))(s)
}
fn collect<'a>(
(map, fun): &rem_utils::annotation::Annotated<'a, &'a syn::ItemFn>,
) -> Vec<Self> {
use rem_utils::labelling::ASTKey;
struct Traverse<'a> {
ast: &'a Annotations<'a>,
constraints: &'a mut Vec<AliasConstraints>,
}
fn lookup_ast<'a>(ast: &Annotations<'a>, ident: &dyn ASTKey) -> Option<Label> {
ast.get(&ident).map(|v| *v)
}
fn add_constraint(constraints: &mut Vec<AliasConstraints>, constraint: AliasConstraints) {
constraints.push(constraint)
}
struct IdentHelper<'a> {
lhs: &'a Label,
ast: &'a Annotations<'a>,
constraints: &'a mut Vec<AliasConstraints>,
}
impl VisitMut for IdentHelper<'_> {
fn visit_ident_mut(&mut self, i: &mut Ident) {
// println!("in ident: {}", i.clone().to_string());
lookup_ast(self.ast, i).and_then(|rhs| {
if *self.lhs.clone().to_string() != rhs.clone().to_string() {
add_constraint(
self.constraints,
AliasConstraints::Assign(self.lhs.clone(), rhs),
);
}
Some(())
});
syn::visit_mut::visit_ident_mut(self, i)
}
}
struct ExprHelper<'a> {
lhs: &'a Label,
ast: &'a Annotations<'a>,
constraints: &'a mut Vec<AliasConstraints>,
}
impl VisitMut for ExprHelper<'_> {
fn visit_expr_mut(&mut self, i: &mut Expr) {
let mut id_helper = IdentHelper {
lhs: self.lhs,
ast: self.ast,
constraints: self.constraints,
};
id_helper.visit_expr_mut(i);
match &i {
Expr::Reference(_) => {
add_constraint(self.constraints, AliasConstraints::Ref(*self.lhs))
}
_ => (),
}
syn::visit_mut::visit_expr_mut(self, i)
}
}
struct StmtHelper<'a> {
lhs: &'a Label,
ast: &'a Annotations<'a>,
constraints: &'a mut Vec<AliasConstraints>,
}
impl VisitMut for StmtHelper<'_> {
fn visit_stmt_mut(&mut self, i: &mut Stmt) {
match i {
Stmt::Expr(e) => {
let mut ident = Ident::new("__IDENT__", Span::call_site());
let mut rhs_helper = LHSHelper { ident: &mut ident };
rhs_helper.visit_expr_mut(e);
if ident.to_string() != "__IDENT__" {
lookup_ast(self.ast, &ident).and_then(|rhs| {
if *self.lhs.clone().to_string() != rhs.clone().to_string() {
add_constraint(
self.constraints,
AliasConstraints::Assign(*self.lhs, rhs),
);
}
Some(())
});
} else {
lookup_ast(self.ast, e).and_then(|rhs| {
if *self.lhs.clone().to_string() != rhs.clone().to_string() {
add_constraint(
self.constraints,
AliasConstraints::Assign(*self.lhs, rhs),
);
}
Some(())
});
}
match e {
Expr::MethodCall(_) => {} // can ret ref but no idea the ret ty
Expr::Call(_) => {}
Expr::Block(b) => match b.block.stmts.last_mut() {
None => {}
Some(s) => self.visit_stmt_mut(s),
},
Expr::Box(b) => {
let mut expr_helper = ExprHelper {
lhs: self.lhs,
ast: self.ast,
constraints: self.constraints,
};
expr_helper.visit_expr_mut(b.expr.as_mut())
}
Expr::Cast(c) => {
let mut expr_helper = ExprHelper {
lhs: self.lhs,
ast: self.ast,
constraints: self.constraints,
};
match c.ty.as_ref() {
Type::Reference(_) => {
expr_helper.visit_expr_mut(c.expr.as_mut())
}
_ => (),
}
}
Expr::If(i) => {
match i.then_branch.stmts.last_mut() {
None => {}
Some(s) => self.visit_stmt_mut(s),
}
match &mut i.else_branch {
None => {}
Some((_, s)) => {
self.visit_stmt_mut(&mut Stmt::Expr(*s.clone().clone()))
}
}
}
Expr::Match(m) => m.arms.iter_mut().for_each(|arm| {
self.visit_stmt_mut(&mut Stmt::Expr(arm.body.as_mut().clone()))
}),
Expr::Paren(e) => self.visit_stmt_mut(&mut Stmt::Expr(*e.expr.clone())),
Expr::Reference(r) => {
add_constraint(self.constraints, AliasConstraints::Ref(*self.lhs));
let mut expr_helper = ExprHelper {
lhs: self.lhs,
ast: self.ast,
constraints: self.constraints,
};
expr_helper.visit_expr_mut(r.expr.as_mut())
}
_ => syn::visit_mut::visit_stmt_mut(self, i),
}
}
_ => syn::visit_mut::visit_stmt_mut(self, i),
}
}
}
struct LHSHelper<'a> {
ident: &'a mut Ident,
}
impl VisitMut for LHSHelper<'_> {
fn visit_ident_mut(&mut self, i: &mut Ident) {
*self.ident = i.clone()
}
}
impl VisitMut for Traverse<'_> {
fn visit_item_fn_mut(&mut self, f: &mut syn::ItemFn) {
self.visit_block_mut(f.block.as_mut());
for arg in &f.sig.inputs {
match arg {
FnArg::Typed(ty) => match ty.ty.as_ref() {
Type::Reference(_) => {
let mut ident = Ident::new("IDENT", Span::call_site());
let mut ident_helper = LHSHelper { ident: &mut ident };
ident_helper.visit_pat_mut(ty.pat.clone().as_mut());
lookup_ast(self.ast, &ident).and_then(|label| {
add_constraint(self.constraints, AliasConstraints::Ref(label));
Some(())
});
}
_ => (),
},
FnArg::Receiver(_) => (),
}
}
}
fn visit_expr_assign_mut(&mut self, i: &mut ExprAssign) {
let mut ident = Ident::new("IDENT", Span::call_site());
let mut ident_helper = LHSHelper { ident: &mut ident };
ident_helper.visit_expr_mut(i.left.as_mut());
lookup_ast(self.ast, &ident).and_then(|label| {
let lhs = &label;
let mut expr_helper = StmtHelper {
lhs,
ast: self.ast,
constraints: self.constraints,
};
expr_helper.visit_stmt_mut(&mut Stmt::Expr(*i.right.clone()));
Some(())
});
}
fn visit_local_mut(&mut self, i: &mut syn::Local) {
let pat = &i.pat;
// println!("local: {}", i.clone().into_token_stream().to_string());
match &*pat {
// Case of the form `let lhs : T = rhs`
syn::Pat::Type(syn::PatType {
pat: box syn::Pat::Ident(p),
ty: box ty,
..
}) => {
match ty {
Type::Reference(_) => {
let ident = &p.ident;
lookup_ast(self.ast, ident).and_then(|label| {
let lhs = &label;
add_constraint(self.constraints, AliasConstraints::Ref(label));
match i.init.clone() {
None => (),
Some((_, init)) => {
let mut expr_helper = StmtHelper {
lhs,
ast: self.ast,
constraints: self.constraints,
};
expr_helper
.visit_stmt_mut(&mut Stmt::Expr(*init.clone()))
}
};
Some(())
});
}
_ => {}
}
syn::visit_mut::visit_local_mut(self, i);
}
syn::Pat::Ident(syn::PatIdent { ident, .. }) => match i.init.clone() {
None => (),
Some((_, init)) => {
lookup_ast(self.ast, ident).and_then(|label| {
let lhs = &label;
let mut expr_helper = StmtHelper {
lhs,
ast: self.ast,
constraints: self.constraints,
};
expr_helper.visit_stmt_mut(&mut Stmt::Expr(*init.clone()));
Some(())
});
}
},
_ => syn::visit_mut::visit_local_mut(self, i),
}
}
}
let mut constraints = vec![];
let mut collector = Traverse {
ast: map,
constraints: &mut constraints,
};
collector.visit_item_fn_mut(&mut fun.clone().clone());
constraints.into_iter().unique().collect()
}
}