1 use errors::Applicability;
2 use syntax::parse::lexer::{StringReader as Lexer};
3 use syntax::parse::{ParseSess, token};
4 use syntax::source_map::FilePathMapping;
5 use syntax_pos::{InnerSpan, FileName};
8 use crate::core::DocContext;
9 use crate::fold::DocFolder;
10 use crate::html::markdown::{self, RustCodeBlock};
11 use crate::passes::Pass;
13 pub const CHECK_CODE_BLOCK_SYNTAX: Pass = Pass {
14 name: "check-code-block-syntax",
15 pass: check_code_block_syntax,
16 description: "validates syntax inside Rust code blocks",
19 pub fn check_code_block_syntax(krate: clean::Crate, cx: &DocContext<'_>) -> clean::Crate {
20 SyntaxChecker { cx }.fold_crate(krate)
23 struct SyntaxChecker<'a, 'tcx> {
24 cx: &'a DocContext<'tcx>,
27 impl<'a, 'tcx> SyntaxChecker<'a, 'tcx> {
28 fn check_rust_syntax(&self, item: &clean::Item, dox: &str, code_block: RustCodeBlock) {
29 let sess = ParseSess::new(FilePathMapping::empty());
30 let source_file = sess.source_map().new_source_file(
31 FileName::Custom(String::from("doctest")),
32 dox[code_block.code].to_owned(),
36 let mut lexer = Lexer::new(&sess, source_file, None);
37 while let Ok(token::Token { kind, .. }) = lexer.try_next_token() {
38 if kind == token::Eof {
43 let errors = lexer.buffer_fatal_errors();
45 if !errors.is_empty() {
52 if let Err(errors) = errors {
53 let mut diag = if let Some(sp) =
54 super::source_span_for_markdown_range(self.cx, &dox, &code_block.range, &item.attrs)
59 .struct_span_warn(sp, "could not parse code block as Rust code");
61 for mut err in errors {
62 diag.note(&format!("error from rustc: {}", err.message()));
66 if code_block.syntax.is_none() && code_block.is_fenced {
67 let sp = sp.from_inner(InnerSpan::new(0, 3));
70 "mark blocks that do not contain Rust code as text",
71 String::from("```text"),
72 Applicability::MachineApplicable,
78 // We couldn't calculate the span of the markdown block that had the error, so our
79 // diagnostics are going to be a bit lacking.
80 let mut diag = self.cx.sess().struct_span_warn(
81 super::span_of_attrs(&item.attrs),
82 "doc comment contains an invalid Rust code block",
85 for mut err in errors {
86 // Don't bother reporting the error, because we can't show where it happened.
90 if code_block.syntax.is_none() && code_block.is_fenced {
91 diag.help("mark blocks that do not contain Rust code as text: ```text");
102 impl<'a, 'tcx> DocFolder for SyntaxChecker<'a, 'tcx> {
103 fn fold_item(&mut self, item: clean::Item) -> Option<clean::Item> {
104 if let Some(dox) = &item.attrs.collapsed_doc_value() {
105 for code_block in markdown::rust_code_blocks(&dox) {
106 self.check_rust_syntax(&item, &dox, code_block);
110 self.fold_item_recur(item)