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-rw-r--r--src/tools/rustfmt/src/chains.rs124
1 files changed, 90 insertions, 34 deletions
diff --git a/src/tools/rustfmt/src/chains.rs b/src/tools/rustfmt/src/chains.rs
index a1a73cf4b..cbe523c6c 100644
--- a/src/tools/rustfmt/src/chains.rs
+++ b/src/tools/rustfmt/src/chains.rs
@@ -70,10 +70,66 @@ use crate::rewrite::{Rewrite, RewriteContext};
use crate::shape::Shape;
use crate::source_map::SpanUtils;
use crate::utils::{
- self, first_line_width, last_line_extendable, last_line_width, mk_sp, rewrite_ident,
- trimmed_last_line_width, wrap_str,
+ self, filtered_str_fits, first_line_width, last_line_extendable, last_line_width, mk_sp,
+ rewrite_ident, trimmed_last_line_width, wrap_str,
};
+use thin_vec::ThinVec;
+
+/// Provides the original input contents from the span
+/// of a chain element with trailing spaces trimmed.
+fn format_overflow_style(span: Span, context: &RewriteContext<'_>) -> Option<String> {
+ context.snippet_provider.span_to_snippet(span).map(|s| {
+ s.lines()
+ .map(|l| l.trim_end())
+ .collect::<Vec<_>>()
+ .join("\n")
+ })
+}
+
+fn format_chain_item(
+ item: &ChainItem,
+ context: &RewriteContext<'_>,
+ rewrite_shape: Shape,
+ allow_overflow: bool,
+) -> Option<String> {
+ if allow_overflow {
+ item.rewrite(context, rewrite_shape)
+ .or_else(|| format_overflow_style(item.span, context))
+ } else {
+ item.rewrite(context, rewrite_shape)
+ }
+}
+
+fn get_block_child_shape(
+ prev_ends_with_block: bool,
+ context: &RewriteContext<'_>,
+ shape: Shape,
+) -> Shape {
+ if prev_ends_with_block {
+ shape.block_indent(0)
+ } else {
+ shape.block_indent(context.config.tab_spaces())
+ }
+ .with_max_width(context.config)
+}
+
+fn get_visual_style_child_shape(
+ context: &RewriteContext<'_>,
+ shape: Shape,
+ offset: usize,
+ parent_overflowing: bool,
+) -> Option<Shape> {
+ if !parent_overflowing {
+ shape
+ .with_max_width(context.config)
+ .offset_left(offset)
+ .map(|s| s.visual_indent(0))
+ } else {
+ Some(shape.visual_indent(offset))
+ }
+}
+
pub(crate) fn rewrite_chain(
expr: &ast::Expr,
context: &RewriteContext<'_>,
@@ -114,7 +170,7 @@ enum ChainItemKind {
MethodCall(
ast::PathSegment,
Vec<ast::GenericArg>,
- Vec<ptr::P<ast::Expr>>,
+ ThinVec<ptr::P<ast::Expr>>,
),
StructField(symbol::Ident),
TupleField(symbol::Ident, bool),
@@ -496,6 +552,8 @@ struct ChainFormatterShared<'a> {
// The number of children in the chain. This is not equal to `self.children.len()`
// because `self.children` will change size as we process the chain.
child_count: usize,
+ // Whether elements are allowed to overflow past the max_width limit
+ allow_overflow: bool,
}
impl<'a> ChainFormatterShared<'a> {
@@ -505,6 +563,8 @@ impl<'a> ChainFormatterShared<'a> {
rewrites: Vec::with_capacity(chain.children.len() + 1),
fits_single_line: false,
child_count: chain.children.len(),
+ // TODO(calebcartwright)
+ allow_overflow: false,
}
}
@@ -517,6 +577,14 @@ impl<'a> ChainFormatterShared<'a> {
}
}
+ fn format_children(&mut self, context: &RewriteContext<'_>, child_shape: Shape) -> Option<()> {
+ for item in &self.children[..self.children.len() - 1] {
+ let rewrite = format_chain_item(item, context, child_shape, self.allow_overflow)?;
+ self.rewrites.push(rewrite);
+ }
+ Some(())
+ }
+
// Rewrite the last child. The last child of a chain requires special treatment. We need to
// know whether 'overflowing' the last child make a better formatting:
//
@@ -729,22 +797,12 @@ impl<'a> ChainFormatter for ChainFormatterBlock<'a> {
}
fn child_shape(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<Shape> {
- Some(
- if self.root_ends_with_block {
- shape.block_indent(0)
- } else {
- shape.block_indent(context.config.tab_spaces())
- }
- .with_max_width(context.config),
- )
+ let block_end = self.root_ends_with_block;
+ Some(get_block_child_shape(block_end, context, shape))
}
fn format_children(&mut self, context: &RewriteContext<'_>, child_shape: Shape) -> Option<()> {
- for item in &self.shared.children[..self.shared.children.len() - 1] {
- let rewrite = item.rewrite(context, child_shape)?;
- self.shared.rewrites.push(rewrite);
- }
- Some(())
+ self.shared.format_children(context, child_shape)
}
fn format_last_child(
@@ -808,15 +866,14 @@ impl<'a> ChainFormatter for ChainFormatterVisual<'a> {
.visual_indent(self.offset)
.sub_width(self.offset)?;
let rewrite = item.rewrite(context, child_shape)?;
- match wrap_str(rewrite, context.config.max_width(), shape) {
- Some(rewrite) => root_rewrite.push_str(&rewrite),
- None => {
- // We couldn't fit in at the visual indent, try the last
- // indent.
- let rewrite = item.rewrite(context, parent_shape)?;
- root_rewrite.push_str(&rewrite);
- self.offset = 0;
- }
+ if filtered_str_fits(&rewrite, context.config.max_width(), shape) {
+ root_rewrite.push_str(&rewrite);
+ } else {
+ // We couldn't fit in at the visual indent, try the last
+ // indent.
+ let rewrite = item.rewrite(context, parent_shape)?;
+ root_rewrite.push_str(&rewrite);
+ self.offset = 0;
}
self.shared.children = &self.shared.children[1..];
@@ -827,18 +884,17 @@ impl<'a> ChainFormatter for ChainFormatterVisual<'a> {
}
fn child_shape(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<Shape> {
- shape
- .with_max_width(context.config)
- .offset_left(self.offset)
- .map(|s| s.visual_indent(0))
+ get_visual_style_child_shape(
+ context,
+ shape,
+ self.offset,
+ // TODO(calebcartwright): self.shared.permissibly_overflowing_parent,
+ false,
+ )
}
fn format_children(&mut self, context: &RewriteContext<'_>, child_shape: Shape) -> Option<()> {
- for item in &self.shared.children[..self.shared.children.len() - 1] {
- let rewrite = item.rewrite(context, child_shape)?;
- self.shared.rewrites.push(rewrite);
- }
- Some(())
+ self.shared.format_children(context, child_shape)
}
fn format_last_child(