1 use errors::Applicability;
2 use rustc_parse::lexer::{StringReader as Lexer};
4 use syntax::sess::ParseSess;
5 use syntax::source_map::FilePathMapping;
6 use syntax_expand::config::process_configure_mod;
7 use syntax_pos::{InnerSpan, FileName};
10 use crate::core::DocContext;
11 use crate::fold::DocFolder;
12 use crate::html::markdown::{self, RustCodeBlock};
13 use crate::passes::Pass;
15 pub const CHECK_CODE_BLOCK_SYNTAX: Pass = Pass {
16 name: "check-code-block-syntax",
17 pass: check_code_block_syntax,
18 description: "validates syntax inside Rust code blocks",
21 pub fn check_code_block_syntax(krate: clean::Crate, cx: &DocContext<'_>) -> clean::Crate {
22 SyntaxChecker { cx }.fold_crate(krate)
25 struct SyntaxChecker<'a, 'tcx> {
26 cx: &'a DocContext<'tcx>,
29 impl<'a, 'tcx> SyntaxChecker<'a, 'tcx> {
30 fn check_rust_syntax(&self, item: &clean::Item, dox: &str, code_block: RustCodeBlock) {
31 let sess = ParseSess::new(FilePathMapping::empty(), process_configure_mod);
32 let source_file = sess.source_map().new_source_file(
33 FileName::Custom(String::from("doctest")),
34 dox[code_block.code].to_owned(),
37 let validation_status = {
38 let mut has_syntax_errors = false;
39 let mut only_whitespace = true;
40 // even if there is a syntax error, we need to run the lexer over the whole file
41 let mut lexer = Lexer::new(&sess, source_file, None);
43 match lexer.next_token().kind {
45 token::Whitespace => (),
46 token::Unknown(..) => has_syntax_errors = true,
47 _ => only_whitespace = false,
51 if has_syntax_errors {
52 Some(CodeBlockInvalid::SyntaxError)
53 } else if only_whitespace {
54 Some(CodeBlockInvalid::Empty)
60 if let Some(code_block_invalid) = validation_status {
61 let mut diag = if let Some(sp) =
62 super::source_span_for_markdown_range(self.cx, &dox, &code_block.range, &item.attrs)
64 let warning_message = match code_block_invalid {
65 CodeBlockInvalid::SyntaxError => "could not parse code block as Rust code",
66 CodeBlockInvalid::Empty => "Rust code block is empty",
69 let mut diag = self.cx.sess().struct_span_warn(sp, warning_message);
71 if code_block.syntax.is_none() && code_block.is_fenced {
72 let sp = sp.from_inner(InnerSpan::new(0, 3));
75 "mark blocks that do not contain Rust code as text",
76 String::from("```text"),
77 Applicability::MachineApplicable,
83 // We couldn't calculate the span of the markdown block that had the error, so our
84 // diagnostics are going to be a bit lacking.
85 let mut diag = self.cx.sess().struct_span_warn(
86 super::span_of_attrs(&item.attrs).unwrap_or(item.source.span()),
87 "doc comment contains an invalid Rust code block",
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)
114 enum CodeBlockInvalid {