Auto merge of #143882 - cjgillot:relative-span-file, r=<try>

Also hash spans inside the same file as relative.

r? `@ghost` for perf

Author: bors

compiler/rustc_query_system/src/ich/hcx.rs

@@ -5,9 +5,7 @@ use rustc_hir::definitions::DefPathHash;
 use rustc_session::Session;
 use rustc_session::cstore::Untracked;
 use rustc_span::source_map::SourceMap;
-use rustc_span::{
-    BytePos, CachingSourceMapView, DUMMY_SP, Span, SpanData, StableSourceFileId, Symbol,
-};
+use rustc_span::{BytePos, CachingSourceMapView, DUMMY_SP, SourceFile, Span, SpanData, Symbol};
 
 use crate::ich;
 
@@ -118,7 +116,7 @@ impl<'a> rustc_span::HashStableContext for StableHashingContext<'a> {
     fn span_data_to_lines_and_cols(
         &mut self,
         span: &SpanData,
-    ) -> Option<(StableSourceFileId, usize, BytePos, usize, BytePos)> {
+    ) -> Option<(&SourceFile, usize, BytePos, usize, BytePos)> {
         self.source_map().span_data_to_lines_and_cols(span)
     }
 

compiler/rustc_span/src/caching_source_map_view.rs

@@ -2,7 +2,7 @@ use std::ops::Range;
 use std::sync::Arc;
 
 use crate::source_map::SourceMap;
-use crate::{BytePos, Pos, RelativeBytePos, SourceFile, SpanData, StableSourceFileId};
+use crate::{BytePos, Pos, RelativeBytePos, SourceFile, SpanData};
 
 #[derive(Clone)]
 struct CacheEntry {
@@ -114,7 +114,7 @@ impl<'sm> CachingSourceMapView<'sm> {
     pub fn span_data_to_lines_and_cols(
         &mut self,
         span_data: &SpanData,
-    ) -> Option<(StableSourceFileId, usize, BytePos, usize, BytePos)> {
+    ) -> Option<(&SourceFile, usize, BytePos, usize, BytePos)> {
         self.time_stamp += 1;
 
         // Check if lo and hi are in the cached lines.
@@ -123,27 +123,25 @@ impl<'sm> CachingSourceMapView<'sm> {
 
         if lo_cache_idx != -1 && hi_cache_idx != -1 {
             // Cache hit for span lo and hi. Check if they belong to the same file.
-            let result = {
-                let lo = &self.line_cache[lo_cache_idx as usize];
-                let hi = &self.line_cache[hi_cache_idx as usize];
+            let lo_file_index = self.line_cache[lo_cache_idx as usize].file_index;
+            let hi_file_index = self.line_cache[hi_cache_idx as usize].file_index;
 
-                if lo.file_index != hi.file_index {
-                    return None;
-                }
-
-                (
-                    lo.file.stable_id,
-                    lo.line_number,
-                    span_data.lo - lo.line.start,
-                    hi.line_number,
-                    span_data.hi - hi.line.start,
-                )
-            };
+            if lo_file_index != hi_file_index {
+                return None;
+            }
 
             self.line_cache[lo_cache_idx as usize].touch(self.time_stamp);
             self.line_cache[hi_cache_idx as usize].touch(self.time_stamp);
 
-            return Some(result);
+            let lo = &self.line_cache[lo_cache_idx as usize];
+            let hi = &self.line_cache[hi_cache_idx as usize];
+            return Some((
+                &*lo.file,
+                lo.line_number,
+                span_data.lo - lo.line.start,
+                hi.line_number,
+                span_data.hi - hi.line.start,
+            ));
         }
 
         // No cache hit or cache hit for only one of span lo and hi.
@@ -226,7 +224,7 @@ impl<'sm> CachingSourceMapView<'sm> {
         assert_eq!(lo.file_index, hi.file_index);
 
         Some((
-            lo.file.stable_id,
+            &*lo.file,
             lo.line_number,
             span_data.lo - lo.line.start,
             hi.line_number,

compiler/rustc_span/src/lib.rs

@@ -2623,7 +2623,7 @@ pub trait HashStableContext {
     fn span_data_to_lines_and_cols(
         &mut self,
         span: &SpanData,
-    ) -> Option<(StableSourceFileId, usize, BytePos, usize, BytePos)>;
+    ) -> Option<(&SourceFile, usize, BytePos, usize, BytePos)>;
     fn hashing_controls(&self) -> HashingControls;
 }
 
@@ -2659,15 +2659,15 @@ where
             return;
         }
 
-        if let Some(parent) = span.parent {
-            let def_span = ctx.def_span(parent).data_untracked();
-            if def_span.contains(span) {
-                // This span is enclosed in a definition: only hash the relative position.
-                Hash::hash(&TAG_RELATIVE_SPAN, hasher);
-                (span.lo - def_span.lo).to_u32().hash_stable(ctx, hasher);
-                (span.hi - def_span.lo).to_u32().hash_stable(ctx, hasher);
-                return;
-            }
+        let parent = span.parent.map(|parent| ctx.def_span(parent).data_untracked());
+        if let Some(parent) = parent
+            && parent.contains(span)
+        {
+            // This span is enclosed in a definition: only hash the relative position.
+            Hash::hash(&TAG_RELATIVE_SPAN, hasher);
+            Hash::hash(&(span.lo - parent.lo), hasher);
+            Hash::hash(&(span.hi - parent.lo), hasher);
+            return;
         }
 
         // If this is not an empty or invalid span, we want to hash the last
@@ -2680,7 +2680,20 @@ where
         };
 
         Hash::hash(&TAG_VALID_SPAN, hasher);
-        Hash::hash(&file, hasher);
+        Hash::hash(&file.stable_id, hasher);
+
+        if let Some(parent) = parent
+            && file.contains(parent.lo)
+        {
+            // This span is relative to another span in the same file,
+            // only hash the relative position.
+            Hash::hash(&TAG_RELATIVE_SPAN, hasher);
+            // Use signed difference as `span` may start before `parent`,
+            // for instance attributes start before their item's span.
+            Hash::hash(&(span.lo.to_u32() as isize - parent.lo.to_u32() as isize), hasher);
+            Hash::hash(&(span.hi.to_u32() as isize - parent.lo.to_u32() as isize), hasher);
+            return;
+        }
 
         // Hash both the length and the end location (line/column) of a span. If we
         // hash only the length, for example, then two otherwise equal spans with