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|
use rustc_hir::def_id::DefId;
use rustc_middle::hir;
use rustc_middle::mir::*;
use rustc_middle::ty::TyCtxt;
use rustc_session::config::MirSpanview;
use rustc_span::{BytePos, Pos, Span};
use std::cmp;
use std::io::{self, Write};
pub const TOOLTIP_INDENT: &str = " ";
const CARET: char = '\u{2038}'; // Unicode `CARET`
const ANNOTATION_LEFT_BRACKET: char = '\u{298a}'; // Unicode `Z NOTATION RIGHT BINDING BRACKET`
const ANNOTATION_RIGHT_BRACKET: char = '\u{2989}'; // Unicode `Z NOTATION LEFT BINDING BRACKET`
const NEW_LINE_SPAN: &str = "</span>\n<span class=\"line\">";
const HEADER: &str = r#"<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">"#;
const START_BODY: &str = r#"</head>
<body>"#;
const FOOTER: &str = r#"</body>
</html>"#;
const STYLE_SECTION: &str = r#"<style>
.line {
counter-increment: line;
}
.line:before {
content: counter(line) ": ";
font-family: Menlo, Monaco, monospace;
font-style: italic;
width: 3.8em;
display: inline-block;
text-align: right;
filter: opacity(50%);
-webkit-user-select: none;
}
.code {
color: #dddddd;
background-color: #222222;
font-family: Menlo, Monaco, monospace;
line-height: 1.4em;
border-bottom: 2px solid #222222;
white-space: pre;
display: inline-block;
}
.odd {
background-color: #55bbff;
color: #223311;
}
.even {
background-color: #ee7756;
color: #551133;
}
.code {
--index: calc(var(--layer) - 1);
padding-top: calc(var(--index) * 0.15em);
filter:
hue-rotate(calc(var(--index) * 25deg))
saturate(calc(100% - (var(--index) * 2%)))
brightness(calc(100% - (var(--index) * 1.5%)));
}
.annotation {
color: #4444ff;
font-family: monospace;
font-style: italic;
display: none;
-webkit-user-select: none;
}
body:active .annotation {
/* requires holding mouse down anywhere on the page */
display: inline-block;
}
span:hover .annotation {
/* requires hover over a span ONLY on its first line */
display: inline-block;
}
</style>"#;
/// Metadata to highlight the span of a MIR BasicBlock, Statement, or Terminator.
#[derive(Clone, Debug)]
pub struct SpanViewable {
pub bb: BasicBlock,
pub span: Span,
pub id: String,
pub tooltip: String,
}
/// Write a spanview HTML+CSS file to analyze MIR element spans.
pub fn write_mir_fn_spanview<'tcx, W>(
tcx: TyCtxt<'tcx>,
body: &Body<'tcx>,
spanview: MirSpanview,
title: &str,
w: &mut W,
) -> io::Result<()>
where
W: Write,
{
let def_id = body.source.def_id();
let hir_body = hir_body(tcx, def_id);
if hir_body.is_none() {
return Ok(());
}
let body_span = hir_body.unwrap().value.span;
let mut span_viewables = Vec::new();
for (bb, data) in body.basic_blocks.iter_enumerated() {
match spanview {
MirSpanview::Statement => {
for (i, statement) in data.statements.iter().enumerate() {
if let Some(span_viewable) =
statement_span_viewable(tcx, body_span, bb, i, statement)
{
span_viewables.push(span_viewable);
}
}
if let Some(span_viewable) = terminator_span_viewable(tcx, body_span, bb, data) {
span_viewables.push(span_viewable);
}
}
MirSpanview::Terminator => {
if let Some(span_viewable) = terminator_span_viewable(tcx, body_span, bb, data) {
span_viewables.push(span_viewable);
}
}
MirSpanview::Block => {
if let Some(span_viewable) = block_span_viewable(tcx, body_span, bb, data) {
span_viewables.push(span_viewable);
}
}
}
}
write_document(tcx, fn_span(tcx, def_id), span_viewables, title, w)?;
Ok(())
}
/// Generate a spanview HTML+CSS document for the given local function `def_id`, and a pre-generated
/// list `SpanViewable`s.
pub fn write_document<'tcx, W>(
tcx: TyCtxt<'tcx>,
spanview_span: Span,
mut span_viewables: Vec<SpanViewable>,
title: &str,
w: &mut W,
) -> io::Result<()>
where
W: Write,
{
let mut from_pos = spanview_span.lo();
let end_pos = spanview_span.hi();
let source_map = tcx.sess.source_map();
let start = source_map.lookup_char_pos(from_pos);
let indent_to_initial_start_col = " ".repeat(start.col.to_usize());
debug!(
"spanview_span={:?}; source is:\n{}{}",
spanview_span,
indent_to_initial_start_col,
source_map.span_to_snippet(spanview_span).expect("function should have printable source")
);
writeln!(w, "{HEADER}")?;
writeln!(w, "<title>{title}</title>")?;
writeln!(w, "{STYLE_SECTION}")?;
writeln!(w, "{START_BODY}")?;
write!(
w,
r#"<div class="code" style="counter-reset: line {}"><span class="line">{}"#,
start.line - 1,
indent_to_initial_start_col,
)?;
span_viewables.sort_unstable_by(|a, b| {
let a = a.span;
let b = b.span;
if a.lo() == b.lo() {
// Sort hi() in reverse order so shorter spans are attempted after longer spans.
// This should give shorter spans a higher "layer", so they are not covered by
// the longer spans.
b.hi().partial_cmp(&a.hi())
} else {
a.lo().partial_cmp(&b.lo())
}
.unwrap()
});
let mut ordered_viewables = &span_viewables[..];
const LOWEST_VIEWABLE_LAYER: usize = 1;
let mut alt = false;
while ordered_viewables.len() > 0 {
debug!(
"calling write_next_viewable with from_pos={}, end_pos={}, and viewables len={}",
from_pos.to_usize(),
end_pos.to_usize(),
ordered_viewables.len()
);
let curr_id = &ordered_viewables[0].id;
let (next_from_pos, next_ordered_viewables) = write_next_viewable_with_overlaps(
tcx,
from_pos,
end_pos,
ordered_viewables,
alt,
LOWEST_VIEWABLE_LAYER,
w,
)?;
debug!(
"DONE calling write_next_viewable, with new from_pos={}, \
and remaining viewables len={}",
next_from_pos.to_usize(),
next_ordered_viewables.len()
);
assert!(
from_pos != next_from_pos || ordered_viewables.len() != next_ordered_viewables.len(),
"write_next_viewable_with_overlaps() must make a state change"
);
from_pos = next_from_pos;
if next_ordered_viewables.len() != ordered_viewables.len() {
ordered_viewables = next_ordered_viewables;
if let Some(next_ordered_viewable) = ordered_viewables.first() {
if &next_ordered_viewable.id != curr_id {
alt = !alt;
}
}
}
}
if from_pos < end_pos {
write_coverage_gap(tcx, from_pos, end_pos, w)?;
}
writeln!(w, r#"</span></div>"#)?;
writeln!(w, "{FOOTER}")?;
Ok(())
}
/// Format a string showing the start line and column, and end line and column within a file.
pub fn source_range_no_file(tcx: TyCtxt<'_>, span: Span) -> String {
let source_map = tcx.sess.source_map();
let start = source_map.lookup_char_pos(span.lo());
let end = source_map.lookup_char_pos(span.hi());
format!("{}:{}-{}:{}", start.line, start.col.to_usize() + 1, end.line, end.col.to_usize() + 1)
}
fn statement_span_viewable<'tcx>(
tcx: TyCtxt<'tcx>,
body_span: Span,
bb: BasicBlock,
i: usize,
statement: &Statement<'tcx>,
) -> Option<SpanViewable> {
let span = statement.source_info.span;
if !body_span.contains(span) {
return None;
}
let id = format!("{}[{}]", bb.index(), i);
let tooltip = tooltip(tcx, &id, span, vec![statement.clone()], &None);
Some(SpanViewable { bb, span, id, tooltip })
}
fn terminator_span_viewable<'tcx>(
tcx: TyCtxt<'tcx>,
body_span: Span,
bb: BasicBlock,
data: &BasicBlockData<'tcx>,
) -> Option<SpanViewable> {
let term = data.terminator();
let span = term.source_info.span;
if !body_span.contains(span) {
return None;
}
let id = format!("{}:{}", bb.index(), term.kind.name());
let tooltip = tooltip(tcx, &id, span, vec![], &data.terminator);
Some(SpanViewable { bb, span, id, tooltip })
}
fn block_span_viewable<'tcx>(
tcx: TyCtxt<'tcx>,
body_span: Span,
bb: BasicBlock,
data: &BasicBlockData<'tcx>,
) -> Option<SpanViewable> {
let span = compute_block_span(data, body_span);
if !body_span.contains(span) {
return None;
}
let id = format!("{}", bb.index());
let tooltip = tooltip(tcx, &id, span, data.statements.clone(), &data.terminator);
Some(SpanViewable { bb, span, id, tooltip })
}
fn compute_block_span(data: &BasicBlockData<'_>, body_span: Span) -> Span {
let mut span = data.terminator().source_info.span;
for statement_span in data.statements.iter().map(|statement| statement.source_info.span) {
// Only combine Spans from the root context, and within the function's body_span.
if statement_span.ctxt().is_root() && body_span.contains(statement_span) {
span = span.to(statement_span);
}
}
span
}
/// Recursively process each ordered span. Spans that overlap will have progressively varying
/// styles, such as increased padding for each overlap. Non-overlapping adjacent spans will
/// have alternating style choices, to help distinguish between them if, visually adjacent.
/// The `layer` is incremented for each overlap, and the `alt` bool alternates between true
/// and false, for each adjacent non-overlapping span. Source code between the spans (code
/// that is not in any coverage region) has neutral styling.
fn write_next_viewable_with_overlaps<'tcx, 'b, W>(
tcx: TyCtxt<'tcx>,
mut from_pos: BytePos,
mut to_pos: BytePos,
ordered_viewables: &'b [SpanViewable],
alt: bool,
layer: usize,
w: &mut W,
) -> io::Result<(BytePos, &'b [SpanViewable])>
where
W: Write,
{
let debug_indent = " ".repeat(layer);
let (viewable, mut remaining_viewables) =
ordered_viewables.split_first().expect("ordered_viewables should have some");
if from_pos < viewable.span.lo() {
debug!(
"{}advance from_pos to next SpanViewable (from from_pos={} to viewable.span.lo()={} \
of {:?}), with to_pos={}",
debug_indent,
from_pos.to_usize(),
viewable.span.lo().to_usize(),
viewable.span,
to_pos.to_usize()
);
let hi = cmp::min(viewable.span.lo(), to_pos);
write_coverage_gap(tcx, from_pos, hi, w)?;
from_pos = hi;
if from_pos < viewable.span.lo() {
debug!(
"{}EARLY RETURN: stopped before getting to next SpanViewable, at {}",
debug_indent,
from_pos.to_usize()
);
return Ok((from_pos, ordered_viewables));
}
}
if from_pos < viewable.span.hi() {
// Set to_pos to the end of this `viewable` to ensure the recursive calls stop writing
// with room to print the tail.
to_pos = cmp::min(viewable.span.hi(), to_pos);
debug!(
"{}update to_pos (if not closer) to viewable.span.hi()={}; to_pos is now {}",
debug_indent,
viewable.span.hi().to_usize(),
to_pos.to_usize()
);
}
let mut subalt = false;
while remaining_viewables.len() > 0 && remaining_viewables[0].span.overlaps(viewable.span) {
let overlapping_viewable = &remaining_viewables[0];
debug!("{}overlapping_viewable.span={:?}", debug_indent, overlapping_viewable.span);
let span =
trim_span(viewable.span, from_pos, cmp::min(overlapping_viewable.span.lo(), to_pos));
let mut some_html_snippet = if from_pos <= viewable.span.hi() || viewable.span.is_empty() {
// `viewable` is not yet fully rendered, so start writing the span, up to either the
// `to_pos` or the next `overlapping_viewable`, whichever comes first.
debug!(
"{}make html_snippet (may not write it if early exit) for partial span {:?} \
of viewable.span {:?}",
debug_indent, span, viewable.span
);
from_pos = span.hi();
make_html_snippet(tcx, span, Some(&viewable))
} else {
None
};
// Defer writing the HTML snippet (until after early return checks) ONLY for empty spans.
// An empty Span with Some(html_snippet) is probably a tail marker. If there is an early
// exit, there should be another opportunity to write the tail marker.
if !span.is_empty() {
if let Some(ref html_snippet) = some_html_snippet {
debug!(
"{}write html_snippet for that partial span of viewable.span {:?}",
debug_indent, viewable.span
);
write_span(html_snippet, &viewable.tooltip, alt, layer, w)?;
}
some_html_snippet = None;
}
if from_pos < overlapping_viewable.span.lo() {
debug!(
"{}EARLY RETURN: from_pos={} has not yet reached the \
overlapping_viewable.span {:?}",
debug_indent,
from_pos.to_usize(),
overlapping_viewable.span
);
// must have reached `to_pos` before reaching the start of the
// `overlapping_viewable.span`
return Ok((from_pos, ordered_viewables));
}
if from_pos == to_pos
&& !(from_pos == overlapping_viewable.span.lo() && overlapping_viewable.span.is_empty())
{
debug!(
"{}EARLY RETURN: from_pos=to_pos={} and overlapping_viewable.span {:?} is not \
empty, or not from_pos",
debug_indent,
to_pos.to_usize(),
overlapping_viewable.span
);
// `to_pos` must have occurred before the overlapping viewable. Return
// `ordered_viewables` so we can continue rendering the `viewable`, from after the
// `to_pos`.
return Ok((from_pos, ordered_viewables));
}
if let Some(ref html_snippet) = some_html_snippet {
debug!(
"{}write html_snippet for that partial span of viewable.span {:?}",
debug_indent, viewable.span
);
write_span(html_snippet, &viewable.tooltip, alt, layer, w)?;
}
debug!(
"{}recursively calling write_next_viewable with from_pos={}, to_pos={}, \
and viewables len={}",
debug_indent,
from_pos.to_usize(),
to_pos.to_usize(),
remaining_viewables.len()
);
// Write the overlaps (and the overlaps' overlaps, if any) up to `to_pos`.
let curr_id = &remaining_viewables[0].id;
let (next_from_pos, next_remaining_viewables) = write_next_viewable_with_overlaps(
tcx,
from_pos,
to_pos,
&remaining_viewables,
subalt,
layer + 1,
w,
)?;
debug!(
"{}DONE recursively calling write_next_viewable, with new from_pos={}, and remaining \
viewables len={}",
debug_indent,
next_from_pos.to_usize(),
next_remaining_viewables.len()
);
assert!(
from_pos != next_from_pos
|| remaining_viewables.len() != next_remaining_viewables.len(),
"write_next_viewable_with_overlaps() must make a state change"
);
from_pos = next_from_pos;
if next_remaining_viewables.len() != remaining_viewables.len() {
remaining_viewables = next_remaining_viewables;
if let Some(next_ordered_viewable) = remaining_viewables.first() {
if &next_ordered_viewable.id != curr_id {
subalt = !subalt;
}
}
}
}
if from_pos <= viewable.span.hi() {
let span = trim_span(viewable.span, from_pos, to_pos);
debug!(
"{}After overlaps, writing (end span?) {:?} of viewable.span {:?}",
debug_indent, span, viewable.span
);
if let Some(ref html_snippet) = make_html_snippet(tcx, span, Some(&viewable)) {
from_pos = span.hi();
write_span(html_snippet, &viewable.tooltip, alt, layer, w)?;
}
}
debug!("{}RETURN: No more overlap", debug_indent);
Ok((
from_pos,
if from_pos < viewable.span.hi() { ordered_viewables } else { remaining_viewables },
))
}
#[inline(always)]
fn write_coverage_gap<W>(tcx: TyCtxt<'_>, lo: BytePos, hi: BytePos, w: &mut W) -> io::Result<()>
where
W: Write,
{
let span = Span::with_root_ctxt(lo, hi);
if let Some(ref html_snippet) = make_html_snippet(tcx, span, None) {
write_span(html_snippet, "", false, 0, w)
} else {
Ok(())
}
}
fn write_span<W>(
html_snippet: &str,
tooltip: &str,
alt: bool,
layer: usize,
w: &mut W,
) -> io::Result<()>
where
W: Write,
{
let maybe_alt_class = if layer > 0 {
if alt { " odd" } else { " even" }
} else {
""
};
let maybe_title_attr = if !tooltip.is_empty() {
format!(" title=\"{}\"", escape_attr(tooltip))
} else {
"".to_owned()
};
if layer == 1 {
write!(w, "<span>")?;
}
for (i, line) in html_snippet.lines().enumerate() {
if i > 0 {
write!(w, "{NEW_LINE_SPAN}")?;
}
write!(
w,
r#"<span class="code{maybe_alt_class}" style="--layer: {layer}"{maybe_title_attr}>{line}</span>"#
)?;
}
// Check for and translate trailing newlines, because `str::lines()` ignores them
if html_snippet.ends_with('\n') {
write!(w, "{NEW_LINE_SPAN}")?;
}
if layer == 1 {
write!(w, "</span>")?;
}
Ok(())
}
fn make_html_snippet(
tcx: TyCtxt<'_>,
span: Span,
some_viewable: Option<&SpanViewable>,
) -> Option<String> {
let source_map = tcx.sess.source_map();
let snippet = source_map
.span_to_snippet(span)
.unwrap_or_else(|err| bug!("span_to_snippet error for span {:?}: {:?}", span, err));
let html_snippet = if let Some(viewable) = some_viewable {
let is_head = span.lo() == viewable.span.lo();
let is_tail = span.hi() == viewable.span.hi();
let mut labeled_snippet = if is_head {
format!(r#"<span class="annotation">{}{}</span>"#, viewable.id, ANNOTATION_LEFT_BRACKET)
} else {
"".to_owned()
};
if span.is_empty() {
if is_head && is_tail {
labeled_snippet.push(CARET);
}
} else {
labeled_snippet.push_str(&escape_html(&snippet));
};
if is_tail {
labeled_snippet.push_str(&format!(
r#"<span class="annotation">{}{}</span>"#,
ANNOTATION_RIGHT_BRACKET, viewable.id
));
}
labeled_snippet
} else {
escape_html(&snippet)
};
if html_snippet.is_empty() { None } else { Some(html_snippet) }
}
fn tooltip<'tcx>(
tcx: TyCtxt<'tcx>,
spanview_id: &str,
span: Span,
statements: Vec<Statement<'tcx>>,
terminator: &Option<Terminator<'tcx>>,
) -> String {
let source_map = tcx.sess.source_map();
let mut text = Vec::new();
text.push(format!("{}: {}:", spanview_id, &source_map.span_to_embeddable_string(span)));
for statement in statements {
let source_range = source_range_no_file(tcx, statement.source_info.span);
text.push(format!(
"\n{}{}: {}: {:?}",
TOOLTIP_INDENT,
source_range,
statement.kind.name(),
statement
));
}
if let Some(term) = terminator {
let source_range = source_range_no_file(tcx, term.source_info.span);
text.push(format!(
"\n{}{}: {}: {:?}",
TOOLTIP_INDENT,
source_range,
term.kind.name(),
term.kind
));
}
text.join("")
}
fn trim_span(span: Span, from_pos: BytePos, to_pos: BytePos) -> Span {
trim_span_hi(trim_span_lo(span, from_pos), to_pos)
}
fn trim_span_lo(span: Span, from_pos: BytePos) -> Span {
if from_pos <= span.lo() { span } else { span.with_lo(cmp::min(span.hi(), from_pos)) }
}
fn trim_span_hi(span: Span, to_pos: BytePos) -> Span {
if to_pos >= span.hi() { span } else { span.with_hi(cmp::max(span.lo(), to_pos)) }
}
fn fn_span(tcx: TyCtxt<'_>, def_id: DefId) -> Span {
let fn_decl_span = tcx.def_span(def_id);
if let Some(body_span) = hir_body(tcx, def_id).map(|hir_body| hir_body.value.span) {
if fn_decl_span.eq_ctxt(body_span) { fn_decl_span.to(body_span) } else { body_span }
} else {
fn_decl_span
}
}
fn hir_body(tcx: TyCtxt<'_>, def_id: DefId) -> Option<&rustc_hir::Body<'_>> {
let hir_node = tcx.hir().get_if_local(def_id).expect("expected DefId is local");
hir::map::associated_body(hir_node).map(|(_, fn_body_id)| tcx.hir().body(fn_body_id))
}
fn escape_html(s: &str) -> String {
s.replace('&', "&").replace('<', "<").replace('>', ">")
}
fn escape_attr(s: &str) -> String {
s.replace('&', "&")
.replace('\"', """)
.replace('\'', "'")
.replace('<', "<")
.replace('>', ">")
}
|
