From 0b4c2cccac30ebcd436e0cfd77b34019c40d4ce3 Mon Sep 17 00:00:00 2001 From: Michael Woerister Date: Fri, 8 Dec 2017 17:07:48 +0100 Subject: [PATCH] incr.comp.: Do less hashing per Span. --- src/librustc/ich/hcx.rs | 15 ++++--- src/librustc/ich/impls_syntax.rs | 2 + src/librustc/ty/maps/on_disk_cache.rs | 2 +- src/librustc_metadata/decoder.rs | 2 + src/libsyntax/codemap.rs | 26 ++----------- src/libsyntax_pos/lib.rs | 56 +++++++++++++++++++++------ 6 files changed, 62 insertions(+), 41 deletions(-) diff --git a/src/librustc/ich/hcx.rs b/src/librustc/ich/hcx.rs index 2d20836814c8f..f9fb668110b10 100644 --- a/src/librustc/ich/hcx.rs +++ b/src/librustc/ich/hcx.rs @@ -338,13 +338,16 @@ impl<'gcx> HashStable> for Span { return std_hash::Hash::hash(&TAG_INVALID_SPAN, hasher); } - let len = span.hi - span.lo; - std_hash::Hash::hash(&TAG_VALID_SPAN, hasher); - std_hash::Hash::hash(&file_lo.name, hasher); - std_hash::Hash::hash(&line_lo, hasher); - std_hash::Hash::hash(&col_lo, hasher); - std_hash::Hash::hash(&len, hasher); + // We truncate the stable_id hash and line and col numbers. The chances + // of causing a collision this way should be minimal. + std_hash::Hash::hash(&(file_lo.stable_id.0 as u64), hasher); + + let col = (col_lo.0 as u64) & 0xFF; + let line = ((line_lo as u64) & 0xFF_FF_FF) << 8; + let len = ((span.hi - span.lo).0 as u64) << 32; + let line_col_len = col | line | len; + std_hash::Hash::hash(&line_col_len, hasher); if span.ctxt == SyntaxContext::empty() { TAG_NO_EXPANSION.hash_stable(hcx, hasher); diff --git a/src/librustc/ich/impls_syntax.rs b/src/librustc/ich/impls_syntax.rs index c25aa10eb1e73..dfb90a5d27feb 100644 --- a/src/librustc/ich/impls_syntax.rs +++ b/src/librustc/ich/impls_syntax.rs @@ -394,6 +394,8 @@ impl<'gcx> HashStable> for FileMap { // Do not hash the source as it is not encoded src: _, src_hash, + // The stable id is just a hash of other fields + stable_id: _, external_src: _, start_pos, end_pos: _, diff --git a/src/librustc/ty/maps/on_disk_cache.rs b/src/librustc/ty/maps/on_disk_cache.rs index 079b518efd898..7d583a3547739 100644 --- a/src/librustc/ty/maps/on_disk_cache.rs +++ b/src/librustc/ty/maps/on_disk_cache.rs @@ -176,7 +176,7 @@ impl<'sess> OnDiskCache<'sess> { let index = FileMapIndex(index as u32); let file_ptr: *const FileMap = &**file as *const _; file_to_file_index.insert(file_ptr, index); - file_index_to_stable_id.insert(index, StableFilemapId::new(&file)); + file_index_to_stable_id.insert(index, file.stable_id); } (file_to_file_index, file_index_to_stable_id) diff --git a/src/librustc_metadata/decoder.rs b/src/librustc_metadata/decoder.rs index 49a017535ffd1..aa7eee366d29b 100644 --- a/src/librustc_metadata/decoder.rs +++ b/src/librustc_metadata/decoder.rs @@ -1124,6 +1124,7 @@ impl<'a, 'tcx> CrateMetadata { let syntax_pos::FileMap { name, name_was_remapped, src_hash, + stable_id, start_pos, end_pos, lines, @@ -1155,6 +1156,7 @@ impl<'a, 'tcx> CrateMetadata { name_was_remapped, self.cnum.as_u32(), src_hash, + stable_id, source_length, lines, multibyte_chars, diff --git a/src/libsyntax/codemap.rs b/src/libsyntax/codemap.rs index 2c91d60ce9d59..07bba29ca4b04 100644 --- a/src/libsyntax/codemap.rs +++ b/src/libsyntax/codemap.rs @@ -23,9 +23,7 @@ pub use syntax_pos::hygiene::{ExpnFormat, ExpnInfo, NameAndSpan}; pub use self::ExpnFormat::*; use rustc_data_structures::fx::FxHashMap; -use rustc_data_structures::stable_hasher::StableHasher; use std::cell::{RefCell, Ref}; -use std::hash::Hash; use std::path::{Path, PathBuf}; use std::rc::Rc; @@ -102,24 +100,6 @@ impl FileLoader for RealFileLoader { } } -// This is a FileMap identifier that is used to correlate FileMaps between -// subsequent compilation sessions (which is something we need to do during -// incremental compilation). -#[derive(Copy, Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Debug)] -pub struct StableFilemapId(u128); - -impl StableFilemapId { - pub fn new(filemap: &FileMap) -> StableFilemapId { - let mut hasher = StableHasher::new(); - - filemap.name.hash(&mut hasher); - filemap.name_was_remapped.hash(&mut hasher); - filemap.unmapped_path.hash(&mut hasher); - - StableFilemapId(hasher.finish()) - } -} - // _____________________________________________________________________________ // CodeMap // @@ -217,7 +197,7 @@ impl CodeMap { self.stable_id_to_filemap .borrow_mut() - .insert(StableFilemapId::new(&filemap), filemap.clone()); + .insert(filemap.stable_id, filemap.clone()); filemap } @@ -246,6 +226,7 @@ impl CodeMap { name_was_remapped: bool, crate_of_origin: u32, src_hash: u128, + stable_id: StableFilemapId, source_len: usize, mut file_local_lines: Vec, mut file_local_multibyte_chars: Vec, @@ -276,6 +257,7 @@ impl CodeMap { crate_of_origin, src: None, src_hash, + stable_id, external_src: RefCell::new(ExternalSource::AbsentOk), start_pos, end_pos, @@ -288,7 +270,7 @@ impl CodeMap { self.stable_id_to_filemap .borrow_mut() - .insert(StableFilemapId::new(&filemap), filemap.clone()); + .insert(stable_id, filemap.clone()); filemap } diff --git a/src/libsyntax_pos/lib.rs b/src/libsyntax_pos/lib.rs index 2a3812516632a..c3d2f0de21dcd 100644 --- a/src/libsyntax_pos/lib.rs +++ b/src/libsyntax_pos/lib.rs @@ -678,6 +678,8 @@ pub struct FileMap { pub src: Option>, /// The source code's hash pub src_hash: u128, + /// The stable id used during incr. comp. + pub stable_id: StableFilemapId, /// The external source code (used for external crates, which will have a `None` /// value as `self.src`. pub external_src: RefCell, @@ -693,15 +695,37 @@ pub struct FileMap { pub non_narrow_chars: RefCell>, } +// This is a FileMap identifier that is used to correlate FileMaps between +// subsequent compilation sessions (which is something we need to do during +// incremental compilation). +#[derive(Copy, Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Debug)] +pub struct StableFilemapId(pub u128); + +impl StableFilemapId { + pub fn new(name: &FileName, + name_was_remapped: bool, + unmapped_path: &FileName) + -> StableFilemapId { + use std::hash::Hash; + + let mut hasher = StableHasher::new(); + name.hash(&mut hasher); + name_was_remapped.hash(&mut hasher); + unmapped_path.hash(&mut hasher); + StableFilemapId(hasher.finish()) + } +} + impl Encodable for FileMap { fn encode(&self, s: &mut S) -> Result<(), S::Error> { s.emit_struct("FileMap", 8, |s| { s.emit_struct_field("name", 0, |s| self.name.encode(s))?; s.emit_struct_field("name_was_remapped", 1, |s| self.name_was_remapped.encode(s))?; - s.emit_struct_field("src_hash", 6, |s| self.src_hash.encode(s))?; - s.emit_struct_field("start_pos", 2, |s| self.start_pos.encode(s))?; - s.emit_struct_field("end_pos", 3, |s| self.end_pos.encode(s))?; - s.emit_struct_field("lines", 4, |s| { + s.emit_struct_field("src_hash", 2, |s| self.src_hash.encode(s))?; + s.emit_struct_field("stable_id", 3, |s| self.stable_id.encode(s))?; + s.emit_struct_field("start_pos", 4, |s| self.start_pos.encode(s))?; + s.emit_struct_field("end_pos", 5, |s| self.end_pos.encode(s))?; + s.emit_struct_field("lines", 6, |s| { let lines = self.lines.borrow(); // store the length s.emit_u32(lines.len() as u32)?; @@ -747,10 +771,10 @@ impl Encodable for FileMap { Ok(()) })?; - s.emit_struct_field("multibyte_chars", 5, |s| { + s.emit_struct_field("multibyte_chars", 7, |s| { (*self.multibyte_chars.borrow()).encode(s) })?; - s.emit_struct_field("non_narrow_chars", 7, |s| { + s.emit_struct_field("non_narrow_chars", 8, |s| { (*self.non_narrow_chars.borrow()).encode(s) }) }) @@ -765,11 +789,13 @@ impl Decodable for FileMap { let name_was_remapped: bool = d.read_struct_field("name_was_remapped", 1, |d| Decodable::decode(d))?; let src_hash: u128 = - d.read_struct_field("src_hash", 6, |d| Decodable::decode(d))?; + d.read_struct_field("src_hash", 2, |d| Decodable::decode(d))?; + let stable_id: StableFilemapId = + d.read_struct_field("stable_id", 3, |d| Decodable::decode(d))?; let start_pos: BytePos = - d.read_struct_field("start_pos", 2, |d| Decodable::decode(d))?; - let end_pos: BytePos = d.read_struct_field("end_pos", 3, |d| Decodable::decode(d))?; - let lines: Vec = d.read_struct_field("lines", 4, |d| { + d.read_struct_field("start_pos", 4, |d| Decodable::decode(d))?; + let end_pos: BytePos = d.read_struct_field("end_pos", 5, |d| Decodable::decode(d))?; + let lines: Vec = d.read_struct_field("lines", 6, |d| { let num_lines: u32 = Decodable::decode(d)?; let mut lines = Vec::with_capacity(num_lines as usize); @@ -798,9 +824,9 @@ impl Decodable for FileMap { Ok(lines) })?; let multibyte_chars: Vec = - d.read_struct_field("multibyte_chars", 5, |d| Decodable::decode(d))?; + d.read_struct_field("multibyte_chars", 7, |d| Decodable::decode(d))?; let non_narrow_chars: Vec = - d.read_struct_field("non_narrow_chars", 7, |d| Decodable::decode(d))?; + d.read_struct_field("non_narrow_chars", 8, |d| Decodable::decode(d))?; Ok(FileMap { name, name_was_remapped, @@ -813,6 +839,7 @@ impl Decodable for FileMap { end_pos, src: None, src_hash, + stable_id, external_src: RefCell::new(ExternalSource::AbsentOk), lines: RefCell::new(lines), multibyte_chars: RefCell::new(multibyte_chars), @@ -840,6 +867,10 @@ impl FileMap { hasher.write(src.as_bytes()); let src_hash = hasher.finish(); + let stable_id = StableFilemapId::new(&name, + name_was_remapped, + &unmapped_path); + let end_pos = start_pos.to_usize() + src.len(); FileMap { @@ -849,6 +880,7 @@ impl FileMap { crate_of_origin: 0, src: Some(Rc::new(src)), src_hash, + stable_id, external_src: RefCell::new(ExternalSource::Unneeded), start_pos, end_pos: Pos::from_usize(end_pos),