1 //! This module analyzes crates to find call sites that can serve as examples in the documentation.
6 use crate::formats::renderer::FormatRenderer;
7 use crate::html::render::Context;
9 use rustc_data_structures::fx::FxHashMap;
12 intravisit::{self, Visitor},
14 use rustc_interface::interface;
15 use rustc_macros::{Decodable, Encodable};
16 use rustc_middle::hir::map::Map;
17 use rustc_middle::hir::nested_filter;
18 use rustc_middle::ty::{self, TyCtxt};
19 use rustc_serialize::{
20 opaque::{Decoder, FileEncoder},
23 use rustc_session::getopts;
25 def_id::{CrateNum, DefPathHash, LOCAL_CRATE},
27 BytePos, FileName, SourceFile,
31 use std::path::PathBuf;
33 #[derive(Debug, Clone)]
34 crate struct ScrapeExamplesOptions {
36 target_crates: Vec<String>,
39 impl ScrapeExamplesOptions {
41 matches: &getopts::Matches,
42 diag: &rustc_errors::Handler,
43 ) -> Result<Option<Self>, i32> {
44 let output_path = matches.opt_str("scrape-examples-output-path");
45 let target_crates = matches.opt_strs("scrape-examples-target-crate");
46 match (output_path, !target_crates.is_empty()) {
47 (Some(output_path), true) => Ok(Some(ScrapeExamplesOptions {
48 output_path: PathBuf::from(output_path),
51 (Some(_), false) | (None, true) => {
52 diag.err("must use --scrape-examples-output-path and --scrape-examples-target-crate together");
55 (None, false) => Ok(None),
60 #[derive(Encodable, Decodable, Debug, Clone)]
61 crate struct SyntaxRange {
62 crate byte_span: (u32, u32),
63 crate line_span: (usize, usize),
67 fn new(span: rustc_span::Span, file: &SourceFile) -> Self {
68 let get_pos = |bytepos: BytePos| file.original_relative_byte_pos(bytepos).0;
69 let get_line = |bytepos: BytePos| file.lookup_line(bytepos).unwrap();
72 byte_span: (get_pos(span.lo()), get_pos(span.hi())),
73 line_span: (get_line(span.lo()), get_line(span.hi())),
78 #[derive(Encodable, Decodable, Debug, Clone)]
79 crate struct CallLocation {
80 crate call_expr: SyntaxRange,
81 crate enclosing_item: SyntaxRange,
86 expr_span: rustc_span::Span,
87 enclosing_item_span: rustc_span::Span,
88 source_file: &SourceFile,
91 call_expr: SyntaxRange::new(expr_span, source_file),
92 enclosing_item: SyntaxRange::new(enclosing_item_span, source_file),
97 #[derive(Encodable, Decodable, Debug, Clone)]
98 crate struct CallData {
99 crate locations: Vec<CallLocation>,
101 crate display_name: String,
102 crate edition: Edition,
105 crate type FnCallLocations = FxHashMap<PathBuf, CallData>;
106 crate type AllCallLocations = FxHashMap<DefPathHash, FnCallLocations>;
108 /// Visitor for traversing a crate and finding instances of function calls.
109 struct FindCalls<'a, 'tcx> {
113 target_crates: Vec<CrateNum>,
114 calls: &'a mut AllCallLocations,
117 impl<'a, 'tcx> Visitor<'tcx> for FindCalls<'a, 'tcx>
121 type NestedFilter = nested_filter::OnlyBodies;
123 fn nested_visit_map(&mut self) -> Self::Map {
127 fn visit_expr(&mut self, ex: &'tcx hir::Expr<'tcx>) {
128 intravisit::walk_expr(self, ex);
132 // If we visit an item that contains an expression outside a function body,
133 // then we need to exit before calling typeck (which will panic). See
134 // test/run-make/rustdoc-scrape-examples-invalid-expr for an example.
136 let owner = hir.local_def_id_to_hir_id(ex.hir_id.owner);
137 if hir.maybe_body_owned_by(owner).is_none() {
141 // Get type of function if expression is a function call
142 let (ty, span) = match ex.kind {
143 hir::ExprKind::Call(f, _) => {
144 let types = tcx.typeck(ex.hir_id.owner);
146 if let Some(ty) = types.node_type_opt(f.hir_id) {
149 trace!("node_type_opt({}) = None", f.hir_id);
153 hir::ExprKind::MethodCall(_, _, span) => {
154 let types = tcx.typeck(ex.hir_id.owner);
155 let def_id = if let Some(def_id) = types.type_dependent_def_id(ex.hir_id) {
158 trace!("type_dependent_def_id({}) = None", ex.hir_id);
161 (tcx.type_of(def_id), span)
168 // If this span comes from a macro expansion, then the source code may not actually show
169 // a use of the given item, so it would be a poor example. Hence, we skip all uses in macros.
170 if span.from_expansion() {
171 trace!("Rejecting expr from macro: {:?}", span);
175 // If the enclosing item has a span coming from a proc macro, then we also don't want to include
177 let enclosing_item_span = tcx
179 .span_with_body(tcx.hir().local_def_id_to_hir_id(tcx.hir().get_parent_item(ex.hir_id)));
180 if enclosing_item_span.from_expansion() {
181 trace!("Rejecting expr ({:?}) from macro item: {:?}", span, enclosing_item_span);
186 enclosing_item_span.contains(span),
187 "Attempted to scrape call at [{:?}] whose enclosing item [{:?}] doesn't contain the span of the call.",
192 // Save call site if the function resolves to a concrete definition
193 if let ty::FnDef(def_id, _) = ty.kind() {
194 if self.target_crates.iter().all(|krate| *krate != def_id.krate) {
195 trace!("Rejecting expr from crate not being documented: {:?}", span);
199 let file = tcx.sess.source_map().lookup_char_pos(span.lo()).file;
200 let file_path = match file.name.clone() {
201 FileName::Real(real_filename) => real_filename.into_local_path(),
205 if let Some(file_path) = file_path {
206 let abs_path = fs::canonicalize(file_path.clone()).unwrap();
208 let mk_call_data = || {
209 let clean_span = crate::clean::types::Span::new(span);
210 let url = cx.href_from_span(clean_span, false).unwrap();
211 let display_name = file_path.display().to_string();
212 let edition = span.edition();
213 CallData { locations: Vec::new(), url, display_name, edition }
216 let fn_key = tcx.def_path_hash(*def_id);
217 let fn_entries = self.calls.entry(fn_key).or_default();
219 trace!("Including expr: {:?}", span);
220 let location = CallLocation::new(span, enclosing_item_span, &file);
221 fn_entries.entry(abs_path).or_insert_with(mk_call_data).locations.push(location);
229 mut renderopts: config::RenderOptions,
230 cache: formats::cache::Cache,
232 options: ScrapeExamplesOptions,
233 ) -> interface::Result<()> {
234 let inner = move || -> Result<(), String> {
235 // Generates source files for examples
236 renderopts.no_emit_shared = true;
237 let (cx, _) = Context::init(krate, renderopts, cache, tcx).map_err(|e| e.to_string())?;
239 // Collect CrateIds corresponding to provided target crates
240 // If two different versions of the crate in the dependency tree, then examples will be collcted from both.
244 .chain([&LOCAL_CRATE])
245 .map(|crate_num| (crate_num, tcx.crate_name(*crate_num)))
246 .collect::<Vec<_>>();
247 let target_crates = options
250 .flat_map(|target| all_crates.iter().filter(move |(_, name)| name.as_str() == target))
251 .map(|(crate_num, _)| **crate_num)
252 .collect::<Vec<_>>();
254 debug!("All crates in TyCtxt: {:?}", all_crates);
255 debug!("Scrape examples target_crates: {:?}", target_crates);
257 // Run call-finder on all items
258 let mut calls = FxHashMap::default();
259 let mut finder = FindCalls { calls: &mut calls, tcx, map: tcx.hir(), cx, target_crates };
260 tcx.hir().visit_all_item_likes(&mut finder.as_deep_visitor());
262 // Sort call locations within a given file in document order
263 for fn_calls in calls.values_mut() {
264 for file_calls in fn_calls.values_mut() {
265 file_calls.locations.sort_by_key(|loc| loc.call_expr.byte_span.0);
269 // Save output to provided path
270 let mut encoder = FileEncoder::new(options.output_path).map_err(|e| e.to_string())?;
271 calls.encode(&mut encoder).map_err(|e| e.to_string())?;
272 encoder.flush().map_err(|e| e.to_string())?;
277 if let Err(e) = inner() {
284 // Note: the Handler must be passed in explicitly because sess isn't available while parsing options
285 crate fn load_call_locations(
286 with_examples: Vec<String>,
287 diag: &rustc_errors::Handler,
288 ) -> Result<AllCallLocations, i32> {
290 let mut all_calls: AllCallLocations = FxHashMap::default();
291 for path in with_examples {
292 let bytes = fs::read(&path).map_err(|e| format!("{} (for path {})", e, path))?;
293 let mut decoder = Decoder::new(&bytes, 0);
294 let calls = AllCallLocations::decode(&mut decoder);
296 for (function, fn_calls) in calls.into_iter() {
297 all_calls.entry(function).or_default().extend(fn_calls.into_iter());
304 inner().map_err(|e: String| {
305 diag.err(&format!("failed to load examples: {}", e));