diff --git a/compiler/rustc_span/src/lib.rs b/compiler/rustc_span/src/lib.rs index d036c078049..480c08291b4 100644 --- a/compiler/rustc_span/src/lib.rs +++ b/compiler/rustc_span/src/lib.rs @@ -1878,16 +1878,37 @@ where return; } + let (_, line_hi, col_hi) = match ctx.byte_pos_to_line_and_col(span.hi) { + Some(pos) => pos, + None => { + Hash::hash(&TAG_INVALID_SPAN, hasher); + span.ctxt.hash_stable(ctx, hasher); + return; + } + }; + Hash::hash(&TAG_VALID_SPAN, hasher); // We truncate the stable ID hash and line and column numbers. The chances // of causing a collision this way should be minimal. Hash::hash(&(file_lo.name_hash 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; - Hash::hash(&line_col_len, hasher); + // 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 + // different end locations will have the same hash. This can cause a problem + // during incremental compilation wherein a previous result for a query that + // depends on the end location of a span will be incorrectly reused when the + // end location of the span it depends on has changed (see issue #74890). A + // similar analysis applies if some query depends specifically on the length + // of the span, but we only hash the end location. So hash both. + + let col_lo_trunc = (col_lo.0 as u64) & 0xFF; + let line_lo_trunc = ((line_lo as u64) & 0xFF_FF_FF) << 8; + let col_hi_trunc = (col_hi.0 as u64) & 0xFF << 32; + let line_hi_trunc = ((line_hi as u64) & 0xFF_FF_FF) << 40; + let col_line = col_lo_trunc | line_lo_trunc | col_hi_trunc | line_hi_trunc; + let len = (span.hi - span.lo).0; + Hash::hash(&col_line, hasher); + Hash::hash(&len, hasher); span.ctxt.hash_stable(ctx, hasher); } } diff --git a/src/test/run-make/incr-prev-body-beyond-eof/Makefile b/src/test/run-make/incr-prev-body-beyond-eof/Makefile new file mode 100644 index 00000000000..428f5f17f91 --- /dev/null +++ b/src/test/run-make/incr-prev-body-beyond-eof/Makefile @@ -0,0 +1,16 @@ +-include ../../run-make-fulldeps/tools.mk + +# Tests that we don't ICE during incremental compilation after modifying a +# function span such that its previous end line exceeds the number of lines +# in the new file, but its start line/column and length remain the same. + +SRC=$(TMPDIR)/src +INCR=$(TMPDIR)/incr + +all: + mkdir $(SRC) + mkdir $(INCR) + cp a.rs $(SRC)/main.rs + $(RUSTC) -C incremental=$(INCR) $(SRC)/main.rs + cp b.rs $(SRC)/main.rs + $(RUSTC) -C incremental=$(INCR) $(SRC)/main.rs diff --git a/src/test/run-make/incr-prev-body-beyond-eof/a.rs b/src/test/run-make/incr-prev-body-beyond-eof/a.rs new file mode 100644 index 00000000000..a12bb96ba5a --- /dev/null +++ b/src/test/run-make/incr-prev-body-beyond-eof/a.rs @@ -0,0 +1,14 @@ +fn main() { + // foo must be used. + foo(); +} + +fn foo() { + // foo's span in a.rs and b.rs must be identical + // with respect to start line/column and length. + assert_eq!(1, 1); + + + + +} diff --git a/src/test/run-make/incr-prev-body-beyond-eof/b.rs b/src/test/run-make/incr-prev-body-beyond-eof/b.rs new file mode 100644 index 00000000000..23e007d0f1c --- /dev/null +++ b/src/test/run-make/incr-prev-body-beyond-eof/b.rs @@ -0,0 +1,10 @@ +fn main() { + // foo must be used. + foo(); +} + +fn foo() { + // foo's span in a.rs and b.rs must be identical + // with respect to start line/column and length. + assert_eq!(1, 1);//// +}