incr. comp.: Take spans into account for ICH

src/librustc/session/config.rs

@@ -908,6 +908,8 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
           "dump MIR state at various points in translation"),
     dump_mir_dir: Option<String> = (None, parse_opt_string, [UNTRACKED],
           "the directory the MIR is dumped into"),
+    perf_stats: bool = (false, parse_bool, [UNTRACKED],
+          "print some performance-related statistics"),
 }
 
 pub fn default_lib_output() -> CrateType {

src/librustc/session/mod.rs

@@ -18,6 +18,7 @@ use session::search_paths::PathKind;
 use session::config::{DebugInfoLevel, PanicStrategy};
 use ty::tls;
 use util::nodemap::{NodeMap, FnvHashMap};
+use util::common::duration_to_secs_str;
 use mir::transform as mir_pass;
 
 use syntax::ast::{NodeId, Name};
@@ -43,6 +44,7 @@ use std::env;
 use std::ffi::CString;
 use std::rc::Rc;
 use std::fmt;
+use std::time::Duration;
 use libc::c_int;
 
 pub mod config;
@@ -104,9 +106,23 @@ pub struct Session {
 
     incr_comp_session: RefCell<IncrCompSession>,
 
+    /// Some measurements that are being gathered during compilation.
+    pub perf_stats: PerfStats,
+
     next_node_id: Cell<ast::NodeId>,
 }
 
+pub struct PerfStats {
+    // The accumulated time needed for computing the SVH of the crate
+    pub svh_time: Cell<Duration>,
+    // The accumulated time spent on computing incr. comp. hashes
+    pub incr_comp_hashes_time: Cell<Duration>,
+    // The number of incr. comp. hash computations performed
+    pub incr_comp_hashes_count: Cell<u64>,
+    // The accumulated time spent on computing symbol hashes
+    pub symbol_hash_time: Cell<Duration>,
+}
+
 impl Session {
     pub fn local_crate_disambiguator(&self) -> token::InternedString {
         self.crate_disambiguator.borrow().clone()
@@ -404,6 +420,17 @@ impl Session {
             None
         }
     }
+
+    pub fn print_perf_stats(&self) {
+        println!("Total time spent computing SVHs:               {}",
+                 duration_to_secs_str(self.perf_stats.svh_time.get()));
+        println!("Total time spent computing incr. comp. hashes: {}",
+                 duration_to_secs_str(self.perf_stats.incr_comp_hashes_time.get()));
+        println!("Total number of incr. comp. hashes computed:   {}",
+                 self.perf_stats.incr_comp_hashes_count.get());
+        println!("Total time spent computing symbol hashes:      {}",
+                 duration_to_secs_str(self.perf_stats.symbol_hash_time.get()));
+    }
 }
 
 pub fn build_session(sopts: config::Options,
@@ -520,6 +547,12 @@ pub fn build_session_(sopts: config::Options,
         available_macros: RefCell::new(HashSet::new()),
         imported_macro_spans: RefCell::new(HashMap::new()),
         incr_comp_session: RefCell::new(IncrCompSession::NotInitialized),
+        perf_stats: PerfStats {
+            svh_time: Cell::new(Duration::from_secs(0)),
+            incr_comp_hashes_time: Cell::new(Duration::from_secs(0)),
+            incr_comp_hashes_count: Cell::new(0),
+            symbol_hash_time: Cell::new(Duration::from_secs(0)),
+        }
     };
 
     init_llvm(&sess);

src/librustc/util/common.rs

@@ -17,7 +17,7 @@ use std::fmt::Debug;
 use std::hash::{Hash, BuildHasher};
 use std::iter::repeat;
 use std::path::Path;
-use std::time::Instant;
+use std::time::{Duration, Instant};
 
 use hir;
 use hir::intravisit;
@@ -47,27 +47,44 @@ pub fn time<T, F>(do_it: bool, what: &str, f: F) -> T where
     let rv = f();
     let dur = start.elapsed();
 
-    // Hack up our own formatting for the duration to make it easier for scripts
-    // to parse (always use the same number of decimal places and the same unit).
-    const NANOS_PER_SEC: f64 = 1_000_000_000.0;
-    let secs = dur.as_secs() as f64;
-    let secs = secs + dur.subsec_nanos() as f64 / NANOS_PER_SEC;
-
     let mem_string = match get_resident() {
         Some(n) => {
             let mb = n as f64 / 1_000_000.0;
             format!("; rss: {}MB", mb.round() as usize)
         }
         None => "".to_owned(),
     };
-    println!("{}time: {:.3}{}\t{}", repeat("  ").take(old).collect::<String>(),
-             secs, mem_string, what);
+    println!("{}time: {}{}\t{}",
+             repeat("  ").take(old).collect::<String>(),
+             duration_to_secs_str(dur),
+             mem_string,
+             what);
 
     DEPTH.with(|slot| slot.set(old));
 
     rv
 }
 
+// Hack up our own formatting for the duration to make it easier for scripts
+// to parse (always use the same number of decimal places and the same unit).
+pub fn duration_to_secs_str(dur: Duration) -> String {
+    const NANOS_PER_SEC: f64 = 1_000_000_000.0;
+    let secs = dur.as_secs() as f64 +
+               dur.subsec_nanos() as f64 / NANOS_PER_SEC;
+
+    format!("{:.3}", secs)
+}
+
+pub fn record_time<T, F>(accu: &Cell<Duration>, f: F) -> T where
+    F: FnOnce() -> T,
+{
+    let start = Instant::now();
+    let rv = f();
+    let duration = start.elapsed();
+    accu.set(duration + accu.get());
+    rv
+}
+
 // Like std::macros::try!, but for Option<>.
 macro_rules! option_try(
     ($e:expr) => (match $e { Some(e) => e, None => return None })

src/librustc_data_structures/fnv.rs

@@ -57,3 +57,9 @@ impl Hasher for FnvHasher {
         self.0
     }
 }
+
+pub fn hash<T: Hash>(v: &T) -> u64 {
+    let mut state = FnvHasher::default();
+    v.hash(&mut state);
+    state.finish()
+}

src/librustc_driver/driver.rs

@@ -233,6 +233,10 @@ pub fn compile_input(sess: &Session,
     // any more, we can finalize it (which involves renaming it)
     rustc_incremental::finalize_session_directory(sess, trans.link.crate_hash);
 
+    if sess.opts.debugging_opts.perf_stats {
+        sess.print_perf_stats();
+    }
+
     controller_entry_point!(compilation_done,
                             sess,
                             CompileState::state_when_compilation_done(input, sess, outdir, output),

src/librustc_incremental/calculate_svh/caching_codemap_view.rs

@@ -0,0 +1,115 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use rustc::ty::TyCtxt;
+use std::rc::Rc;
+use syntax::codemap::CodeMap;
+use syntax_pos::{BytePos, FileMap};
+
+#[derive(Clone)]
+struct CacheEntry {
+    time_stamp: usize,
+    line_number: usize,
+    line_start: BytePos,
+    line_end: BytePos,
+    file: Rc<FileMap>,
+}
+
+pub struct CachingCodemapView<'tcx> {
+    codemap: &'tcx CodeMap,
+    line_cache: [CacheEntry; 3],
+    time_stamp: usize,
+}
+
+impl<'tcx> CachingCodemapView<'tcx> {
+    pub fn new<'a>(tcx: TyCtxt<'a, 'tcx, 'tcx>) -> CachingCodemapView<'tcx> {
+        let codemap = tcx.sess.codemap();
+        let first_file = codemap.files.borrow()[0].clone();
+        let entry = CacheEntry {
+            time_stamp: 0,
+            line_number: 0,
+            line_start: BytePos(0),
+            line_end: BytePos(0),
+            file: first_file,
+        };
+
+        CachingCodemapView {
+            codemap: codemap,
+            line_cache: [entry.clone(), entry.clone(), entry.clone()],
+            time_stamp: 0,
+        }
+    }
+
+    pub fn codemap(&self) -> &'tcx CodeMap {
+        self.codemap
+    }
+
+    pub fn byte_pos_to_line_and_col(&mut self,
+                                    pos: BytePos)
+                                    -> Option<(Rc<FileMap>, usize, BytePos)> {
+        self.time_stamp += 1;
+
+        // Check if the position is in one of the cached lines
+        for cache_entry in self.line_cache.iter_mut() {
+            if pos >= cache_entry.line_start && pos < cache_entry.line_end {
+                cache_entry.time_stamp = self.time_stamp;
+                return Some((cache_entry.file.clone(),
+                             cache_entry.line_number,
+                             pos - cache_entry.line_start));
+            }
+        }
+
+        // No cache hit ...
+        let mut oldest = 0;
+        for index in 1 .. self.line_cache.len() {
+            if self.line_cache[index].time_stamp < self.line_cache[oldest].time_stamp {
+                oldest = index;
+            }
+        }
+
+        let cache_entry = &mut self.line_cache[oldest];
+
+        // If the entry doesn't point to the correct file, fix it up
+        if pos < cache_entry.file.start_pos || pos >= cache_entry.file.end_pos {
+            let file_valid;
+            let files = self.codemap.files.borrow();
+
+            if files.len() > 0 {
+                let file_index = self.codemap.lookup_filemap_idx(pos);
+                let file = files[file_index].clone();
+
+                if pos >= file.start_pos && pos < file.end_pos {
+                    cache_entry.file = file;
+                    file_valid = true;
+                } else {
+                    file_valid = false;
+                }
+            } else {
+                file_valid = false;
+            }
+
+            if !file_valid {
+                return None;
+            }
+        }
+
+        let line_index = cache_entry.file.lookup_line(pos).unwrap();
+        let line_bounds = cache_entry.file.line_bounds(line_index);
+
+        cache_entry.line_number = line_index + 1;
+        cache_entry.line_start = line_bounds.0;
+        cache_entry.line_end = line_bounds.1;
+        cache_entry.time_stamp = self.time_stamp;
+
+        return Some((cache_entry.file.clone(),
+                     cache_entry.line_number,
+                     pos - cache_entry.line_start));
+    }
+}

src/librustc_incremental/calculate_svh/mod.rs

@@ -35,32 +35,46 @@ use rustc::hir::def_id::{CRATE_DEF_INDEX, DefId};
 use rustc::hir::intravisit as visit;
 use rustc::ty::TyCtxt;
 use rustc_data_structures::fnv::FnvHashMap;
+use rustc::util::common::record_time;
+use rustc::session::config::DebugInfoLevel::NoDebugInfo;
 
 use self::def_path_hash::DefPathHashes;
 use self::svh_visitor::StrictVersionHashVisitor;
+use self::caching_codemap_view::CachingCodemapView;
 
 mod def_path_hash;
 mod svh_visitor;
+mod caching_codemap_view;
 
 pub type IncrementalHashesMap = FnvHashMap<DepNode<DefId>, u64>;
 
 pub fn compute_incremental_hashes_map<'a, 'tcx: 'a>(tcx: TyCtxt<'a, 'tcx, 'tcx>)
                                                     -> IncrementalHashesMap {
     let _ignore = tcx.dep_graph.in_ignore();
     let krate = tcx.map.krate();
-    let mut visitor = HashItemsVisitor { tcx: tcx,
-                                         hashes: FnvHashMap(),
-                                         def_path_hashes: DefPathHashes::new(tcx) };
-    visitor.calculate_def_id(DefId::local(CRATE_DEF_INDEX), |v| visit::walk_crate(v, krate));
-    krate.visit_all_items(&mut visitor);
-    visitor.compute_crate_hash();
+    let hash_spans = tcx.sess.opts.debuginfo != NoDebugInfo;
+    let mut visitor = HashItemsVisitor {
+        tcx: tcx,
+        hashes: FnvHashMap(),
+        def_path_hashes: DefPathHashes::new(tcx),
+        codemap: CachingCodemapView::new(tcx),
+        hash_spans: hash_spans,
+    };
+    record_time(&tcx.sess.perf_stats.incr_comp_hashes_time, || {
+        visitor.calculate_def_id(DefId::local(CRATE_DEF_INDEX),
+                                 |v| visit::walk_crate(v, krate));
+        krate.visit_all_items(&mut visitor);
+    });
+    record_time(&tcx.sess.perf_stats.svh_time, || visitor.compute_crate_hash());
     visitor.hashes
 }
 
 struct HashItemsVisitor<'a, 'tcx: 'a> {
     tcx: TyCtxt<'a, 'tcx, 'tcx>,
     def_path_hashes: DefPathHashes<'a, 'tcx>,
+    codemap: CachingCodemapView<'tcx>,
     hashes: IncrementalHashesMap,
+    hash_spans: bool,
 }
 
 impl<'a, 'tcx> HashItemsVisitor<'a, 'tcx> {
@@ -81,7 +95,9 @@ impl<'a, 'tcx> HashItemsVisitor<'a, 'tcx> {
         let mut state = SipHasher::new();
         walk_op(&mut StrictVersionHashVisitor::new(&mut state,
                                                    self.tcx,
-                                                   &mut self.def_path_hashes));
+                                                   &mut self.def_path_hashes,
+                                                   &mut self.codemap,
+                                                   self.hash_spans));
         let item_hash = state.finish();
         self.hashes.insert(DepNode::Hir(def_id), item_hash);
         debug!("calculate_item_hash: def_id={:?} hash={:?}", def_id, item_hash);
@@ -117,9 +133,13 @@ impl<'a, 'tcx> HashItemsVisitor<'a, 'tcx> {
             item_hashes.hash(&mut crate_state);
         }
 
-        for attr in &krate.attrs {
-            debug!("krate attr {:?}", attr);
-            attr.meta().hash(&mut crate_state);
+        {
+            let mut visitor = StrictVersionHashVisitor::new(&mut crate_state,
+                                                            self.tcx,
+                                                            &mut self.def_path_hashes,
+                                                            &mut self.codemap,
+                                                            self.hash_spans);
+            visitor.hash_attributes(&krate.attrs);
         }
 
         let crate_hash = crate_state.finish();