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use rustc_data_structures::sync::{Lock, Lrc};
use rustc_errors::{
emitter::Emitter, translation::Translate, Applicability, Diagnostic, Handler,
LazyFallbackBundle, LintDiagnosticBuilder,
};
use rustc_parse::parse_stream_from_source_str;
use rustc_session::parse::ParseSess;
use rustc_span::hygiene::{AstPass, ExpnData, ExpnKind, LocalExpnId};
use rustc_span::source_map::{FilePathMapping, SourceMap};
use rustc_span::{FileName, InnerSpan, DUMMY_SP};
use crate::clean;
use crate::core::DocContext;
use crate::html::markdown::{self, RustCodeBlock};
use crate::passes::Pass;
use crate::visit::DocVisitor;
pub(crate) const CHECK_CODE_BLOCK_SYNTAX: Pass = Pass {
name: "check-code-block-syntax",
run: check_code_block_syntax,
description: "validates syntax inside Rust code blocks",
};
pub(crate) fn check_code_block_syntax(
krate: clean::Crate,
cx: &mut DocContext<'_>,
) -> clean::Crate {
SyntaxChecker { cx }.visit_crate(&krate);
krate
}
struct SyntaxChecker<'a, 'tcx> {
cx: &'a DocContext<'tcx>,
}
impl<'a, 'tcx> SyntaxChecker<'a, 'tcx> {
fn check_rust_syntax(&self, item: &clean::Item, dox: &str, code_block: RustCodeBlock) {
let buffer = Lrc::new(Lock::new(Buffer::default()));
let fallback_bundle =
rustc_errors::fallback_fluent_bundle(rustc_errors::DEFAULT_LOCALE_RESOURCES, false);
let emitter = BufferEmitter { buffer: Lrc::clone(&buffer), fallback_bundle };
let sm = Lrc::new(SourceMap::new(FilePathMapping::empty()));
let handler = Handler::with_emitter(false, None, Box::new(emitter));
let source = dox[code_block.code].to_owned();
let sess = ParseSess::with_span_handler(handler, sm);
let edition = code_block.lang_string.edition.unwrap_or_else(|| self.cx.tcx.sess.edition());
let expn_data = ExpnData::default(
ExpnKind::AstPass(AstPass::TestHarness),
DUMMY_SP,
edition,
None,
None,
);
let expn_id =
self.cx.tcx.with_stable_hashing_context(|hcx| LocalExpnId::fresh(expn_data, hcx));
let span = DUMMY_SP.fresh_expansion(expn_id);
let is_empty = rustc_driver::catch_fatal_errors(|| {
parse_stream_from_source_str(
FileName::Custom(String::from("doctest")),
source,
&sess,
Some(span),
)
.is_empty()
})
.unwrap_or(false);
let buffer = buffer.borrow();
if !buffer.has_errors && !is_empty {
return;
}
let Some(local_id) = item.item_id.as_def_id().and_then(|x| x.as_local())
else {
return;
};
let hir_id = self.cx.tcx.hir().local_def_id_to_hir_id(local_id);
let empty_block = code_block.lang_string == Default::default() && code_block.is_fenced;
let is_ignore = code_block.lang_string.ignore != markdown::Ignore::None;
let (sp, precise_span) = match super::source_span_for_markdown_range(
self.cx.tcx,
dox,
&code_block.range,
&item.attrs,
) {
Some(sp) => (sp, true),
None => (item.attr_span(self.cx.tcx), false),
};
let diag_builder = |lint: LintDiagnosticBuilder<'_, ()>| {
let explanation = if is_ignore {
"`ignore` code blocks require valid Rust code for syntax highlighting; \
mark blocks that do not contain Rust code as text"
} else {
"mark blocks that do not contain Rust code as text"
};
let msg = if buffer.has_errors {
"could not parse code block as Rust code"
} else {
"Rust code block is empty"
};
let mut diag = lint.build(msg);
if precise_span {
if is_ignore {
diag.span_help(
sp.from_inner(InnerSpan::new(0, 3)),
&format!("{}: ```text", explanation),
);
} else if empty_block {
diag.span_suggestion(
sp.from_inner(InnerSpan::new(0, 3)).shrink_to_hi(),
explanation,
"text",
Applicability::MachineApplicable,
);
}
} else if empty_block || is_ignore {
diag.help(&format!("{}: ```text", explanation));
}
for message in buffer.messages.iter() {
diag.note(message);
}
diag.emit();
};
self.cx.tcx.struct_span_lint_hir(
crate::lint::INVALID_RUST_CODEBLOCKS,
hir_id,
sp,
diag_builder,
);
}
}
impl<'a, 'tcx> DocVisitor for SyntaxChecker<'a, 'tcx> {
fn visit_item(&mut self, item: &clean::Item) {
if let Some(dox) = &item.attrs.collapsed_doc_value() {
let sp = item.attr_span(self.cx.tcx);
let extra = crate::html::markdown::ExtraInfo::new_did(
self.cx.tcx,
item.item_id.expect_def_id(),
sp,
);
for code_block in markdown::rust_code_blocks(dox, &extra) {
self.check_rust_syntax(item, dox, code_block);
}
}
self.visit_item_recur(item)
}
}
#[derive(Default)]
struct Buffer {
messages: Vec<String>,
has_errors: bool,
}
struct BufferEmitter {
buffer: Lrc<Lock<Buffer>>,
fallback_bundle: LazyFallbackBundle,
}
impl Translate for BufferEmitter {
fn fluent_bundle(&self) -> Option<&Lrc<rustc_errors::FluentBundle>> {
None
}
fn fallback_fluent_bundle(&self) -> &rustc_errors::FluentBundle {
&**self.fallback_bundle
}
}
impl Emitter for BufferEmitter {
fn emit_diagnostic(&mut self, diag: &Diagnostic) {
let mut buffer = self.buffer.borrow_mut();
buffer.messages.push(format!("error from rustc: {}", diag.message[0].0.expect_str()));
if diag.is_error() {
buffer.has_errors = true;
}
}
fn source_map(&self) -> Option<&Lrc<SourceMap>> {
None
}
}