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::ty::{self, TyCtxt};
18 use rustc_serialize::{
19 opaque::{Decoder, FileEncoder},
22 use rustc_session::getopts;
24 def_id::{CrateNum, DefPathHash, LOCAL_CRATE},
26 BytePos, FileName, SourceFile,
30 use std::path::PathBuf;
32 #[derive(Debug, Clone)]
33 crate struct ScrapeExamplesOptions {
35 target_crates: Vec<String>,
38 impl ScrapeExamplesOptions {
40 matches: &getopts::Matches,
41 diag: &rustc_errors::Handler,
42 ) -> Result<Option<Self>, i32> {
43 let output_path = matches.opt_str("scrape-examples-output-path");
44 let target_crates = matches.opt_strs("scrape-examples-target-crate");
45 match (output_path, !target_crates.is_empty()) {
46 (Some(output_path), true) => Ok(Some(ScrapeExamplesOptions {
47 output_path: PathBuf::from(output_path),
50 (Some(_), false) | (None, true) => {
51 diag.err("must use --scrape-examples-output-path and --scrape-examples-target-crate together");
54 (None, false) => Ok(None),
59 #[derive(Encodable, Decodable, Debug, Clone)]
60 crate struct SyntaxRange {
61 crate byte_span: (u32, u32),
62 crate line_span: (usize, usize),
66 fn new(span: rustc_span::Span, file: &SourceFile) -> Self {
67 let get_pos = |bytepos: BytePos| file.original_relative_byte_pos(bytepos).0;
68 let get_line = |bytepos: BytePos| file.lookup_line(bytepos).unwrap();
71 byte_span: (get_pos(span.lo()), get_pos(span.hi())),
72 line_span: (get_line(span.lo()), get_line(span.hi())),
77 #[derive(Encodable, Decodable, Debug, Clone)]
78 crate struct CallLocation {
79 crate call_expr: SyntaxRange,
80 crate enclosing_item: SyntaxRange,
85 expr_span: rustc_span::Span,
86 enclosing_item_span: rustc_span::Span,
87 source_file: &SourceFile,
90 call_expr: SyntaxRange::new(expr_span, source_file),
91 enclosing_item: SyntaxRange::new(enclosing_item_span, source_file),
96 #[derive(Encodable, Decodable, Debug, Clone)]
97 crate struct CallData {
98 crate locations: Vec<CallLocation>,
100 crate display_name: String,
101 crate edition: Edition,
104 crate type FnCallLocations = FxHashMap<PathBuf, CallData>;
105 crate type AllCallLocations = FxHashMap<DefPathHash, FnCallLocations>;
107 /// Visitor for traversing a crate and finding instances of function calls.
108 struct FindCalls<'a, 'tcx> {
112 target_crates: Vec<CrateNum>,
113 calls: &'a mut AllCallLocations,
116 impl<'a, 'tcx> Visitor<'tcx> for FindCalls<'a, 'tcx>
120 type Map = Map<'tcx>;
122 fn nested_visit_map(&mut self) -> intravisit::NestedVisitorMap<Self::Map> {
123 intravisit::NestedVisitorMap::OnlyBodies(self.map)
126 fn visit_expr(&mut self, ex: &'tcx hir::Expr<'tcx>) {
127 intravisit::walk_expr(self, ex);
131 // If we visit an item that contains an expression outside a function body,
132 // then we need to exit before calling typeck (which will panic). See
133 // test/run-make/rustdoc-scrape-examples-invalid-expr for an example.
135 let owner = hir.local_def_id_to_hir_id(ex.hir_id.owner);
136 if hir.maybe_body_owned_by(owner).is_none() {
140 // Get type of function if expression is a function call
141 let (ty, span) = match ex.kind {
142 hir::ExprKind::Call(f, _) => {
143 let types = tcx.typeck(ex.hir_id.owner);
145 if let Some(ty) = types.node_type_opt(f.hir_id) {
148 trace!("node_type_opt({}) = None", f.hir_id);
152 hir::ExprKind::MethodCall(_, _, _, span) => {
153 let types = tcx.typeck(ex.hir_id.owner);
154 let def_id = if let Some(def_id) = types.type_dependent_def_id(ex.hir_id) {
157 trace!("type_dependent_def_id({}) = None", ex.hir_id);
160 (tcx.type_of(def_id), span)
167 // If this span comes from a macro expansion, then the source code may not actually show
168 // a use of the given item, so it would be a poor example. Hence, we skip all uses in macros.
169 if span.from_expansion() {
170 trace!("Rejecting expr from macro: {:?}", span);
174 // If the enclosing item has a span coming from a proc macro, then we also don't want to include
176 let enclosing_item_span = tcx.hir().span_with_body(tcx.hir().get_parent_item(ex.hir_id));
177 if enclosing_item_span.from_expansion() {
178 trace!("Rejecting expr ({:?}) from macro item: {:?}", span, enclosing_item_span);
183 enclosing_item_span.contains(span),
184 "Attempted to scrape call at [{:?}] whose enclosing item [{:?}] doesn't contain the span of the call.",
189 // Save call site if the function resolves to a concrete definition
190 if let ty::FnDef(def_id, _) = ty.kind() {
191 if self.target_crates.iter().all(|krate| *krate != def_id.krate) {
192 trace!("Rejecting expr from crate not being documented: {:?}", span);
196 let file = tcx.sess.source_map().lookup_char_pos(span.lo()).file;
197 let file_path = match file.name.clone() {
198 FileName::Real(real_filename) => real_filename.into_local_path(),
202 if let Some(file_path) = file_path {
203 let abs_path = fs::canonicalize(file_path.clone()).unwrap();
205 let mk_call_data = || {
206 let clean_span = crate::clean::types::Span::new(span);
207 let url = cx.href_from_span(clean_span, false).unwrap();
208 let display_name = file_path.display().to_string();
209 let edition = span.edition();
210 CallData { locations: Vec::new(), url, display_name, edition }
213 let fn_key = tcx.def_path_hash(*def_id);
214 let fn_entries = self.calls.entry(fn_key).or_default();
216 trace!("Including expr: {:?}", span);
217 let location = CallLocation::new(span, enclosing_item_span, &file);
218 fn_entries.entry(abs_path).or_insert_with(mk_call_data).locations.push(location);
226 renderopts: config::RenderOptions,
227 cache: formats::cache::Cache,
229 options: ScrapeExamplesOptions,
230 ) -> interface::Result<()> {
231 let inner = move || -> Result<(), String> {
232 // Generates source files for examples
233 let (cx, _) = Context::init(krate, renderopts, cache, tcx).map_err(|e| e.to_string())?;
235 // Collect CrateIds corresponding to provided target crates
236 // If two different versions of the crate in the dependency tree, then examples will be collcted from both.
240 .chain([&LOCAL_CRATE])
241 .map(|crate_num| (crate_num, tcx.crate_name(*crate_num)))
242 .collect::<Vec<_>>();
243 let target_crates = options
246 .map(|target| all_crates.iter().filter(move |(_, name)| name.as_str() == target))
248 .map(|(crate_num, _)| **crate_num)
249 .collect::<Vec<_>>();
251 debug!("All crates in TyCtxt: {:?}", all_crates);
252 debug!("Scrape examples target_crates: {:?}", target_crates);
254 // Run call-finder on all items
255 let mut calls = FxHashMap::default();
256 let mut finder = FindCalls { calls: &mut calls, tcx, map: tcx.hir(), cx, target_crates };
257 tcx.hir().visit_all_item_likes(&mut finder.as_deep_visitor());
259 // Sort call locations within a given file in document order
260 for fn_calls in calls.values_mut() {
261 for file_calls in fn_calls.values_mut() {
262 file_calls.locations.sort_by_key(|loc| loc.call_expr.byte_span.0);
266 // Save output to provided path
267 let mut encoder = FileEncoder::new(options.output_path).map_err(|e| e.to_string())?;
268 calls.encode(&mut encoder).map_err(|e| e.to_string())?;
269 encoder.flush().map_err(|e| e.to_string())?;
274 if let Err(e) = inner() {
281 // Note: the Handler must be passed in explicitly because sess isn't available while parsing options
282 crate fn load_call_locations(
283 with_examples: Vec<String>,
284 diag: &rustc_errors::Handler,
285 ) -> Result<AllCallLocations, i32> {
287 let mut all_calls: AllCallLocations = FxHashMap::default();
288 for path in with_examples {
289 let bytes = fs::read(&path).map_err(|e| format!("{} (for path {})", e, path))?;
290 let mut decoder = Decoder::new(&bytes, 0);
291 let calls = AllCallLocations::decode(&mut decoder)?;
293 for (function, fn_calls) in calls.into_iter() {
294 all_calls.entry(function).or_default().extend(fn_calls.into_iter());
301 inner().map_err(|e: String| {
302 diag.err(&format!("failed to load examples: {}", e));