rust/crates/hir-def/src/body/pretty.rs
2023-06-11 00:39:28 +03:30

680 lines
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Rust
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//! A pretty-printer for HIR.
use std::fmt::{self, Write};
use hir_expand::db::ExpandDatabase;
use syntax::ast::HasName;
use crate::{
hir::{
Array, BindingAnnotation, BindingId, CaptureBy, ClosureKind, Literal, LiteralOrConst,
Movability, Statement,
},
pretty::{print_generic_args, print_path, print_type_ref},
type_ref::TypeRef,
};
use super::*;
pub(super) fn print_body_hir(db: &dyn DefDatabase, body: &Body, owner: DefWithBodyId) -> String {
let header = match owner {
DefWithBodyId::FunctionId(it) => {
let item_tree_id = it.lookup(db).id;
format!(
"fn {}",
item_tree_id.item_tree(db)[item_tree_id.value].name.display(db.upcast())
)
}
DefWithBodyId::StaticId(it) => {
let item_tree_id = it.lookup(db).id;
format!(
"static {} = ",
item_tree_id.item_tree(db)[item_tree_id.value].name.display(db.upcast())
)
}
DefWithBodyId::ConstId(it) => {
let item_tree_id = it.lookup(db).id;
let name = match &item_tree_id.item_tree(db)[item_tree_id.value].name {
Some(name) => name.display(db.upcast()).to_string(),
None => "_".to_string(),
};
format!("const {name} = ")
}
DefWithBodyId::InTypeConstId(_) => format!("In type const = "),
DefWithBodyId::VariantId(it) => {
let src = it.parent.child_source(db);
let variant = &src.value[it.local_id];
match &variant.name() {
Some(name) => name.to_string(),
None => "_".to_string(),
}
}
};
let mut p =
Printer { db: db.upcast(), body, buf: header, indent_level: 0, needs_indent: false };
if let DefWithBodyId::FunctionId(it) = owner {
p.buf.push('(');
body.params.iter().zip(&db.function_data(it).params).for_each(|(&param, ty)| {
p.print_pat(param);
p.buf.push(':');
p.print_type_ref(ty);
});
p.buf.push(')');
p.buf.push(' ');
}
p.print_expr(body.body_expr);
if matches!(owner, DefWithBodyId::StaticId(_) | DefWithBodyId::ConstId(_)) {
p.buf.push(';');
}
p.buf
}
pub(super) fn print_expr_hir(
db: &dyn DefDatabase,
body: &Body,
_owner: DefWithBodyId,
expr: ExprId,
) -> String {
let mut p =
Printer { db: db.upcast(), body, buf: String::new(), indent_level: 0, needs_indent: false };
p.print_expr(expr);
p.buf
}
macro_rules! w {
($dst:expr, $($arg:tt)*) => {
{ let _ = write!($dst, $($arg)*); }
};
}
macro_rules! wln {
($dst:expr) => {
{ let _ = writeln!($dst); }
};
($dst:expr, $($arg:tt)*) => {
{ let _ = writeln!($dst, $($arg)*); }
};
}
struct Printer<'a> {
db: &'a dyn ExpandDatabase,
body: &'a Body,
buf: String,
indent_level: usize,
needs_indent: bool,
}
impl<'a> Write for Printer<'a> {
fn write_str(&mut self, s: &str) -> fmt::Result {
for line in s.split_inclusive('\n') {
if self.needs_indent {
match self.buf.chars().rev().find(|ch| *ch != ' ') {
Some('\n') | None => {}
_ => self.buf.push('\n'),
}
self.buf.push_str(&" ".repeat(self.indent_level));
self.needs_indent = false;
}
self.buf.push_str(line);
self.needs_indent = line.ends_with('\n');
}
Ok(())
}
}
impl<'a> Printer<'a> {
fn indented(&mut self, f: impl FnOnce(&mut Self)) {
self.indent_level += 1;
wln!(self);
f(self);
self.indent_level -= 1;
self.buf = self.buf.trim_end_matches('\n').to_string();
}
fn whitespace(&mut self) {
match self.buf.chars().next_back() {
None | Some('\n' | ' ') => {}
_ => self.buf.push(' '),
}
}
fn newline(&mut self) {
match self.buf.chars().rev().find(|ch| *ch != ' ') {
Some('\n') | None => {}
_ => writeln!(self).unwrap(),
}
}
fn print_expr(&mut self, expr: ExprId) {
let expr = &self.body[expr];
match expr {
Expr::Missing => w!(self, "<EFBFBD>"),
Expr::Underscore => w!(self, "_"),
Expr::Path(path) => self.print_path(path),
Expr::If { condition, then_branch, else_branch } => {
w!(self, "if ");
self.print_expr(*condition);
w!(self, " ");
self.print_expr(*then_branch);
if let Some(els) = *else_branch {
w!(self, " else ");
self.print_expr(els);
}
}
Expr::Let { pat, expr } => {
w!(self, "let ");
self.print_pat(*pat);
w!(self, " = ");
self.print_expr(*expr);
}
Expr::Loop { body, label } => {
if let Some(lbl) = label {
w!(self, "{}: ", self.body[*lbl].name.display(self.db));
}
w!(self, "loop ");
self.print_expr(*body);
}
Expr::While { condition, body, label } => {
if let Some(lbl) = label {
w!(self, "{}: ", self.body[*lbl].name.display(self.db));
}
w!(self, "while ");
self.print_expr(*condition);
self.print_expr(*body);
}
Expr::Call { callee, args, is_assignee_expr: _ } => {
self.print_expr(*callee);
w!(self, "(");
if !args.is_empty() {
self.indented(|p| {
for arg in &**args {
p.print_expr(*arg);
wln!(p, ",");
}
});
}
w!(self, ")");
}
Expr::MethodCall { receiver, method_name, args, generic_args } => {
self.print_expr(*receiver);
w!(self, ".{}", method_name.display(self.db));
if let Some(args) = generic_args {
w!(self, "::<");
print_generic_args(self.db, args, self).unwrap();
w!(self, ">");
}
w!(self, "(");
if !args.is_empty() {
self.indented(|p| {
for arg in &**args {
p.print_expr(*arg);
wln!(p, ",");
}
});
}
w!(self, ")");
}
Expr::Match { expr, arms } => {
w!(self, "match ");
self.print_expr(*expr);
w!(self, " {{");
self.indented(|p| {
for arm in &**arms {
p.print_pat(arm.pat);
if let Some(guard) = arm.guard {
w!(p, " if ");
p.print_expr(guard);
}
w!(p, " => ");
p.print_expr(arm.expr);
wln!(p, ",");
}
});
wln!(self, "}}");
}
Expr::Continue { label } => {
w!(self, "continue");
if let Some(lbl) = label {
w!(self, " {}", self.body[*lbl].name.display(self.db));
}
}
Expr::Break { expr, label } => {
w!(self, "break");
if let Some(lbl) = label {
w!(self, " {}", self.body[*lbl].name.display(self.db));
}
if let Some(expr) = expr {
self.whitespace();
self.print_expr(*expr);
}
}
Expr::Return { expr } => {
w!(self, "return");
if let Some(expr) = expr {
self.whitespace();
self.print_expr(*expr);
}
}
Expr::Yield { expr } => {
w!(self, "yield");
if let Some(expr) = expr {
self.whitespace();
self.print_expr(*expr);
}
}
Expr::Yeet { expr } => {
w!(self, "do");
self.whitespace();
w!(self, "yeet");
if let Some(expr) = expr {
self.whitespace();
self.print_expr(*expr);
}
}
Expr::RecordLit { path, fields, spread, ellipsis, is_assignee_expr: _ } => {
match path {
Some(path) => self.print_path(path),
None => w!(self, "<EFBFBD>"),
}
w!(self, "{{");
self.indented(|p| {
for field in &**fields {
w!(p, "{}: ", field.name.display(self.db));
p.print_expr(field.expr);
wln!(p, ",");
}
if let Some(spread) = spread {
w!(p, "..");
p.print_expr(*spread);
wln!(p);
}
if *ellipsis {
wln!(p, "..");
}
});
w!(self, "}}");
}
Expr::Field { expr, name } => {
self.print_expr(*expr);
w!(self, ".{}", name.display(self.db));
}
Expr::Await { expr } => {
self.print_expr(*expr);
w!(self, ".await");
}
Expr::Cast { expr, type_ref } => {
self.print_expr(*expr);
w!(self, " as ");
self.print_type_ref(type_ref);
}
Expr::Ref { expr, rawness, mutability } => {
w!(self, "&");
if rawness.is_raw() {
w!(self, "raw ");
}
if mutability.is_mut() {
w!(self, "mut ");
}
self.print_expr(*expr);
}
Expr::Box { expr } => {
w!(self, "box ");
self.print_expr(*expr);
}
Expr::UnaryOp { expr, op } => {
let op = match op {
ast::UnaryOp::Deref => "*",
ast::UnaryOp::Not => "!",
ast::UnaryOp::Neg => "-",
};
w!(self, "{}", op);
self.print_expr(*expr);
}
Expr::BinaryOp { lhs, rhs, op } => {
let (bra, ket) = match op {
None | Some(ast::BinaryOp::Assignment { .. }) => ("", ""),
_ => ("(", ")"),
};
w!(self, "{}", bra);
self.print_expr(*lhs);
w!(self, "{} ", ket);
match op {
Some(op) => w!(self, "{}", op),
None => w!(self, "<EFBFBD>"), // :)
}
w!(self, " {}", bra);
self.print_expr(*rhs);
w!(self, "{}", ket);
}
Expr::Range { lhs, rhs, range_type } => {
if let Some(lhs) = lhs {
w!(self, "(");
self.print_expr(*lhs);
w!(self, ") ");
}
let range = match range_type {
ast::RangeOp::Exclusive => "..",
ast::RangeOp::Inclusive => "..=",
};
w!(self, "{}", range);
if let Some(rhs) = rhs {
w!(self, "(");
self.print_expr(*rhs);
w!(self, ") ");
}
}
Expr::Index { base, index } => {
self.print_expr(*base);
w!(self, "[");
self.print_expr(*index);
w!(self, "]");
}
Expr::Closure { args, arg_types, ret_type, body, closure_kind, capture_by } => {
match closure_kind {
ClosureKind::Generator(Movability::Static) => {
w!(self, "static ");
}
ClosureKind::Async => {
w!(self, "async ");
}
_ => (),
}
match capture_by {
CaptureBy::Value => {
w!(self, "move ");
}
CaptureBy::Ref => (),
}
w!(self, "|");
for (i, (pat, ty)) in args.iter().zip(arg_types.iter()).enumerate() {
if i != 0 {
w!(self, ", ");
}
self.print_pat(*pat);
if let Some(ty) = ty {
w!(self, ": ");
self.print_type_ref(ty);
}
}
w!(self, "|");
if let Some(ret_ty) = ret_type {
w!(self, " -> ");
self.print_type_ref(ret_ty);
}
self.whitespace();
self.print_expr(*body);
}
Expr::Tuple { exprs, is_assignee_expr: _ } => {
w!(self, "(");
for expr in exprs.iter() {
self.print_expr(*expr);
w!(self, ", ");
}
w!(self, ")");
}
Expr::Array(arr) => {
w!(self, "[");
if !matches!(arr, Array::ElementList { elements, .. } if elements.is_empty()) {
self.indented(|p| match arr {
Array::ElementList { elements, is_assignee_expr: _ } => {
for elem in elements.iter() {
p.print_expr(*elem);
w!(p, ", ");
}
}
Array::Repeat { initializer, repeat } => {
p.print_expr(*initializer);
w!(p, "; ");
p.print_expr(*repeat);
}
});
self.newline();
}
w!(self, "]");
}
Expr::Literal(lit) => self.print_literal(lit),
Expr::Block { id: _, statements, tail, label } => {
let label = label.map(|lbl| format!("{}: ", self.body[lbl].name.display(self.db)));
self.print_block(label.as_deref(), statements, tail);
}
Expr::Unsafe { id: _, statements, tail } => {
self.print_block(Some("unsafe "), statements, tail);
}
Expr::Async { id: _, statements, tail } => {
self.print_block(Some("async "), statements, tail);
}
Expr::Const(id) => {
w!(self, "const {{ /* {id:?} */ }}");
}
}
}
fn print_block(
&mut self,
label: Option<&str>,
statements: &[Statement],
tail: &Option<la_arena::Idx<Expr>>,
) {
self.whitespace();
if let Some(lbl) = label {
w!(self, "{}", lbl);
}
w!(self, "{{");
if !statements.is_empty() || tail.is_some() {
self.indented(|p| {
for stmt in statements {
p.print_stmt(stmt);
}
if let Some(tail) = tail {
p.print_expr(*tail);
}
p.newline();
});
}
w!(self, "}}");
}
fn print_pat(&mut self, pat: PatId) {
let pat = &self.body[pat];
match pat {
Pat::Missing => w!(self, "<EFBFBD>"),
Pat::Wild => w!(self, "_"),
Pat::Tuple { args, ellipsis } => {
w!(self, "(");
for (i, pat) in args.iter().enumerate() {
if i != 0 {
w!(self, ", ");
}
if *ellipsis == Some(i) {
w!(self, ".., ");
}
self.print_pat(*pat);
}
w!(self, ")");
}
Pat::Or(pats) => {
for (i, pat) in pats.iter().enumerate() {
if i != 0 {
w!(self, " | ");
}
self.print_pat(*pat);
}
}
Pat::Record { path, args, ellipsis } => {
match path {
Some(path) => self.print_path(path),
None => w!(self, "<EFBFBD>"),
}
w!(self, " {{");
self.indented(|p| {
for arg in args.iter() {
w!(p, "{}: ", arg.name.display(self.db));
p.print_pat(arg.pat);
wln!(p, ",");
}
if *ellipsis {
wln!(p, "..");
}
});
w!(self, "}}");
}
Pat::Range { start, end } => {
if let Some(start) = start {
self.print_literal_or_const(start);
}
w!(self, "..=");
if let Some(end) = end {
self.print_literal_or_const(end);
}
}
Pat::Slice { prefix, slice, suffix } => {
w!(self, "[");
for pat in prefix.iter() {
self.print_pat(*pat);
w!(self, ", ");
}
if let Some(pat) = slice {
self.print_pat(*pat);
w!(self, ", ");
}
for pat in suffix.iter() {
self.print_pat(*pat);
w!(self, ", ");
}
w!(self, "]");
}
Pat::Path(path) => self.print_path(path),
Pat::Lit(expr) => self.print_expr(*expr),
Pat::Bind { id, subpat } => {
self.print_binding(*id);
if let Some(pat) = subpat {
self.whitespace();
self.print_pat(*pat);
}
}
Pat::TupleStruct { path, args, ellipsis } => {
match path {
Some(path) => self.print_path(path),
None => w!(self, "<EFBFBD>"),
}
w!(self, "(");
for (i, arg) in args.iter().enumerate() {
if i != 0 {
w!(self, ", ");
}
if *ellipsis == Some(i) {
w!(self, ", ..");
}
self.print_pat(*arg);
}
w!(self, ")");
}
Pat::Ref { pat, mutability } => {
w!(self, "&");
if mutability.is_mut() {
w!(self, "mut ");
}
self.print_pat(*pat);
}
Pat::Box { inner } => {
w!(self, "box ");
self.print_pat(*inner);
}
Pat::ConstBlock(c) => {
w!(self, "const ");
self.print_expr(*c);
}
}
}
fn print_stmt(&mut self, stmt: &Statement) {
match stmt {
Statement::Let { pat, type_ref, initializer, else_branch } => {
w!(self, "let ");
self.print_pat(*pat);
if let Some(ty) = type_ref {
w!(self, ": ");
self.print_type_ref(ty);
}
if let Some(init) = initializer {
w!(self, " = ");
self.print_expr(*init);
}
if let Some(els) = else_branch {
w!(self, " else ");
self.print_expr(*els);
}
wln!(self, ";");
}
Statement::Expr { expr, has_semi } => {
self.print_expr(*expr);
if *has_semi {
w!(self, ";");
}
wln!(self);
}
}
}
fn print_literal_or_const(&mut self, literal_or_const: &LiteralOrConst) {
match literal_or_const {
LiteralOrConst::Literal(l) => self.print_literal(l),
LiteralOrConst::Const(c) => self.print_path(c),
}
}
fn print_literal(&mut self, literal: &Literal) {
match literal {
Literal::String(it) => w!(self, "{:?}", it),
Literal::ByteString(it) => w!(self, "\"{}\"", it.escape_ascii()),
Literal::CString(it) => w!(self, "\"{}\\0\"", it),
Literal::Char(it) => w!(self, "'{}'", it.escape_debug()),
Literal::Bool(it) => w!(self, "{}", it),
Literal::Int(i, suffix) => {
w!(self, "{}", i);
if let Some(suffix) = suffix {
w!(self, "{}", suffix);
}
}
Literal::Uint(i, suffix) => {
w!(self, "{}", i);
if let Some(suffix) = suffix {
w!(self, "{}", suffix);
}
}
Literal::Float(f, suffix) => {
w!(self, "{}", f);
if let Some(suffix) = suffix {
w!(self, "{}", suffix);
}
}
}
}
fn print_type_ref(&mut self, ty: &TypeRef) {
print_type_ref(self.db, ty, self).unwrap();
}
fn print_path(&mut self, path: &Path) {
print_path(self.db, path, self).unwrap();
}
fn print_binding(&mut self, id: BindingId) {
let Binding { name, mode, .. } = &self.body.bindings[id];
let mode = match mode {
BindingAnnotation::Unannotated => "",
BindingAnnotation::Mutable => "mut ",
BindingAnnotation::Ref => "ref ",
BindingAnnotation::RefMut => "ref mut ",
};
w!(self, "{}{}", mode, name.display(self.db));
}
}