rust/src/rewrite.rs

99 lines
2.9 KiB
Rust

// A generic trait to abstract the rewriting of an element (of the AST).
use std::cell::{Cell, RefCell};
use std::rc::Rc;
use rustc_ast::ptr;
use rustc_span::Span;
use crate::config::{Config, IndentStyle};
use crate::parse::session::ParseSess;
use crate::shape::Shape;
use crate::skip::SkipContext;
use crate::visitor::SnippetProvider;
use crate::FormatReport;
pub(crate) trait Rewrite {
/// Rewrite self into shape.
fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String>;
}
impl<T: Rewrite> Rewrite for ptr::P<T> {
fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> {
(**self).rewrite(context, shape)
}
}
#[derive(Clone)]
pub(crate) struct RewriteContext<'a> {
pub(crate) parse_sess: &'a ParseSess,
pub(crate) config: &'a Config,
pub(crate) inside_macro: Rc<Cell<bool>>,
// Force block indent style even if we are using visual indent style.
pub(crate) use_block: Cell<bool>,
// When `is_if_else_block` is true, unindent the comment on top
// of the `else` or `else if`.
pub(crate) is_if_else_block: Cell<bool>,
// When rewriting chain, veto going multi line except the last element
pub(crate) force_one_line_chain: Cell<bool>,
pub(crate) snippet_provider: &'a SnippetProvider,
// Used for `format_snippet`
pub(crate) macro_rewrite_failure: Cell<bool>,
pub(crate) is_macro_def: bool,
pub(crate) report: FormatReport,
pub(crate) skip_context: SkipContext,
pub(crate) skipped_range: Rc<RefCell<Vec<(usize, usize)>>>,
}
pub(crate) struct InsideMacroGuard {
is_nested_macro_context: bool,
inside_macro_ref: Rc<Cell<bool>>,
}
impl InsideMacroGuard {
pub(crate) fn is_nested(&self) -> bool {
self.is_nested_macro_context
}
}
impl Drop for InsideMacroGuard {
fn drop(&mut self) {
self.inside_macro_ref.replace(self.is_nested_macro_context);
}
}
impl<'a> RewriteContext<'a> {
pub(crate) fn snippet(&self, span: Span) -> &str {
self.snippet_provider.span_to_snippet(span).unwrap()
}
/// Returns `true` if we should use block indent style for rewriting function call.
pub(crate) fn use_block_indent(&self) -> bool {
self.config.indent_style() == IndentStyle::Block || self.use_block.get()
}
pub(crate) fn budget(&self, used_width: usize) -> usize {
self.config.max_width().saturating_sub(used_width)
}
pub(crate) fn inside_macro(&self) -> bool {
self.inside_macro.get()
}
pub(crate) fn enter_macro(&self) -> InsideMacroGuard {
let is_nested_macro_context = self.inside_macro.replace(true);
InsideMacroGuard {
is_nested_macro_context,
inside_macro_ref: self.inside_macro.clone(),
}
}
pub(crate) fn leave_macro(&self) {
self.inside_macro.replace(false);
}
pub(crate) fn is_if_else_block(&self) -> bool {
self.is_if_else_block.get()
}
}