1 use rustc_data_structures::sync::{Lock, Lrc};
2 use rustc_errors::{emitter::Emitter, Applicability, Diagnostic, Handler};
3 use rustc_middle::lint::LintDiagnosticBuilder;
4 use rustc_parse::parse_stream_from_source_str;
5 use rustc_session::parse::ParseSess;
6 use rustc_span::source_map::{FilePathMapping, SourceMap};
7 use rustc_span::{hygiene::AstPass, ExpnData, ExpnKind, FileName, InnerSpan, DUMMY_SP};
10 use crate::core::DocContext;
11 use crate::html::markdown::{self, RustCodeBlock};
12 use crate::passes::Pass;
13 use crate::visit::DocVisitor;
15 crate const CHECK_CODE_BLOCK_SYNTAX: Pass = Pass {
16 name: "check-code-block-syntax",
17 run: check_code_block_syntax,
18 description: "validates syntax inside Rust code blocks",
21 crate fn check_code_block_syntax(krate: clean::Crate, cx: &mut DocContext<'_>) -> clean::Crate {
22 SyntaxChecker { cx }.visit_crate(&krate);
26 struct SyntaxChecker<'a, 'tcx> {
27 cx: &'a DocContext<'tcx>,
30 impl<'a, 'tcx> SyntaxChecker<'a, 'tcx> {
31 fn check_rust_syntax(&self, item: &clean::Item, dox: &str, code_block: RustCodeBlock) {
32 let buffer = Lrc::new(Lock::new(Buffer::default()));
33 let emitter = BufferEmitter { buffer: Lrc::clone(&buffer) };
35 let sm = Lrc::new(SourceMap::new(FilePathMapping::empty()));
36 let handler = Handler::with_emitter(false, None, Box::new(emitter));
37 let source = dox[code_block.code].to_owned();
38 let sess = ParseSess::with_span_handler(handler, sm);
40 let edition = code_block.lang_string.edition.unwrap_or_else(|| self.cx.tcx.sess.edition());
41 let expn_data = ExpnData::default(
42 ExpnKind::AstPass(AstPass::TestHarness),
48 let span = DUMMY_SP.fresh_expansion(expn_data, self.cx.tcx.create_stable_hashing_context());
50 let is_empty = rustc_driver::catch_fatal_errors(|| {
51 parse_stream_from_source_str(
52 FileName::Custom(String::from("doctest")),
60 let buffer = buffer.borrow();
62 if !buffer.has_errors && !is_empty {
63 // No errors in a non-empty program.
67 let local_id = match item.def_id.as_def_id().and_then(|x| x.as_local()) {
69 // We don't need to check the syntax for other crates so returning
70 // without doing anything should not be a problem.
74 let hir_id = self.cx.tcx.hir().local_def_id_to_hir_id(local_id);
75 let empty_block = code_block.lang_string == Default::default() && code_block.is_fenced;
76 let is_ignore = code_block.lang_string.ignore != markdown::Ignore::None;
78 // The span and whether it is precise or not.
79 let (sp, precise_span) = match super::source_span_for_markdown_range(
85 Some(sp) => (sp, true),
86 None => (item.attr_span(self.cx.tcx), false),
89 // lambda that will use the lint to start a new diagnostic and add
90 // a suggestion to it when needed.
91 let diag_builder = |lint: LintDiagnosticBuilder<'_>| {
92 let explanation = if is_ignore {
93 "`ignore` code blocks require valid Rust code for syntax highlighting; \
94 mark blocks that do not contain Rust code as text"
96 "mark blocks that do not contain Rust code as text"
98 let msg = if buffer.has_errors {
99 "could not parse code block as Rust code"
101 "Rust code block is empty"
103 let mut diag = lint.build(msg);
107 // giving an accurate suggestion is hard because `ignore` might not have come first in the list.
108 // just give a `help` instead.
110 sp.from_inner(InnerSpan::new(0, 3)),
111 &format!("{}: ```text", explanation),
113 } else if empty_block {
114 diag.span_suggestion(
115 sp.from_inner(InnerSpan::new(0, 3)).shrink_to_hi(),
117 String::from("text"),
118 Applicability::MachineApplicable,
121 } else if empty_block || is_ignore {
122 diag.help(&format!("{}: ```text", explanation));
125 // FIXME(#67563): Provide more context for these errors by displaying the spans inline.
126 for message in buffer.messages.iter() {
133 // Finally build and emit the completed diagnostic.
134 // All points of divergence have been handled earlier so this can be
135 // done the same way whether the span is precise or not.
136 self.cx.tcx.struct_span_lint_hir(
137 crate::lint::INVALID_RUST_CODEBLOCKS,
145 impl<'a, 'tcx> DocVisitor for SyntaxChecker<'a, 'tcx> {
146 fn visit_item(&mut self, item: &clean::Item) {
147 if let Some(dox) = &item.attrs.collapsed_doc_value() {
148 let sp = item.attr_span(self.cx.tcx);
149 let extra = crate::html::markdown::ExtraInfo::new_did(
151 item.def_id.expect_def_id(),
154 for code_block in markdown::rust_code_blocks(dox, &extra) {
155 self.check_rust_syntax(&item, dox, code_block);
159 self.visit_item_recur(item)
165 messages: Vec<String>,
169 struct BufferEmitter {
170 buffer: Lrc<Lock<Buffer>>,
173 impl Emitter for BufferEmitter {
174 fn emit_diagnostic(&mut self, diag: &Diagnostic) {
175 let mut buffer = self.buffer.borrow_mut();
176 buffer.messages.push(format!("error from rustc: {}", diag.message[0].0));
178 buffer.has_errors = true;
182 fn source_map(&self) -> Option<&Lrc<SourceMap>> {