1 use errors::Applicability;
2 use syntax::parse::lexer::{StringReader as Lexer};
4 use syntax::sess::ParseSess;
5 use syntax::source_map::FilePathMapping;
6 use syntax_pos::{InnerSpan, FileName};
9 use crate::core::DocContext;
10 use crate::fold::DocFolder;
11 use crate::html::markdown::{self, RustCodeBlock};
12 use crate::passes::Pass;
14 pub const CHECK_CODE_BLOCK_SYNTAX: Pass = Pass {
15 name: "check-code-block-syntax",
16 pass: check_code_block_syntax,
17 description: "validates syntax inside Rust code blocks",
20 pub fn check_code_block_syntax(krate: clean::Crate, cx: &DocContext<'_>) -> clean::Crate {
21 SyntaxChecker { cx }.fold_crate(krate)
24 struct SyntaxChecker<'a, 'tcx> {
25 cx: &'a DocContext<'tcx>,
28 impl<'a, 'tcx> SyntaxChecker<'a, 'tcx> {
29 fn check_rust_syntax(&self, item: &clean::Item, dox: &str, code_block: RustCodeBlock) {
30 let sess = ParseSess::new(FilePathMapping::empty());
31 let source_file = sess.source_map().new_source_file(
32 FileName::Custom(String::from("doctest")),
33 dox[code_block.code].to_owned(),
36 let validation_status = {
37 let mut has_syntax_errors = false;
38 let mut only_whitespace = true;
39 // even if there is a syntax error, we need to run the lexer over the whole file
40 let mut lexer = Lexer::new(&sess, source_file, None);
42 match lexer.next_token().kind {
44 token::Whitespace => (),
45 token::Unknown(..) => has_syntax_errors = true,
46 _ => only_whitespace = false,
50 if has_syntax_errors {
51 Some(CodeBlockInvalid::SyntaxError)
52 } else if only_whitespace {
53 Some(CodeBlockInvalid::Empty)
59 if let Some(code_block_invalid) = validation_status {
60 let mut diag = if let Some(sp) =
61 super::source_span_for_markdown_range(self.cx, &dox, &code_block.range, &item.attrs)
63 let warning_message = match code_block_invalid {
64 CodeBlockInvalid::SyntaxError => "could not parse code block as Rust code",
65 CodeBlockInvalid::Empty => "Rust code block is empty",
68 let mut diag = self.cx.sess().struct_span_warn(sp, warning_message);
70 if code_block.syntax.is_none() && code_block.is_fenced {
71 let sp = sp.from_inner(InnerSpan::new(0, 3));
74 "mark blocks that do not contain Rust code as text",
75 String::from("```text"),
76 Applicability::MachineApplicable,
82 // We couldn't calculate the span of the markdown block that had the error, so our
83 // diagnostics are going to be a bit lacking.
84 let mut diag = self.cx.sess().struct_span_warn(
85 super::span_of_attrs(&item.attrs).unwrap_or(item.source.span()),
86 "doc comment contains an invalid Rust code block",
89 if code_block.syntax.is_none() && code_block.is_fenced {
90 diag.help("mark blocks that do not contain Rust code as text: ```text");
101 impl<'a, 'tcx> DocFolder for SyntaxChecker<'a, 'tcx> {
102 fn fold_item(&mut self, item: clean::Item) -> Option<clean::Item> {
103 if let Some(dox) = &item.attrs.collapsed_doc_value() {
104 for code_block in markdown::rust_code_blocks(&dox) {
105 self.check_rust_syntax(&item, &dox, code_block);
109 self.fold_item_recur(item)
113 enum CodeBlockInvalid {