From feec92c42341ce45f00e7f45341e12a7fef78e53 Mon Sep 17 00:00:00 2001 From: Keith Randall Date: Mon, 14 Feb 2022 14:57:55 -0800 Subject: [PATCH] [release-branch.go1.17] cmd/compile: drop column info when line number saturates When line number saturates, we can end up getting non-monotonic position info, because the start of the next line after line=lineMax,col=2 is line=lineMax,col=1. Instead, if line==lineMax, make the column always 0 (no column info). If the line number is wrong, having column info probably isn't that helpful. Fixes #52095 Change-Id: If3d90472691b1f6163654f3505e2cb98467f2383 Reviewed-on: https://go-review.googlesource.com/c/go/+/385795 Trust: Keith Randall Reviewed-by: Than McIntosh (cherry picked from commit 1de2344af16125ae2fabed226f2fbb40a150238c) Reviewed-on: https://go-review.googlesource.com/c/go/+/401315 Reviewed-by: Keith Randall Run-TryBot: Keith Randall TryBot-Result: Gopher Robot Reviewed-by: Ian Lance Taylor Reviewed-by: Austin Clements --- src/cmd/internal/src/pos.go | 5 ++++- src/cmd/internal/src/pos_test.go | 14 +++++++------- 2 files changed, 11 insertions(+), 8 deletions(-) diff --git a/src/cmd/internal/src/pos.go b/src/cmd/internal/src/pos.go index b6816a56e0..373a22a7f2 100644 --- a/src/cmd/internal/src/pos.go +++ b/src/cmd/internal/src/pos.go @@ -389,9 +389,12 @@ func makeBogusLico() lico { } func makeLico(line, col uint) lico { - if line > lineMax { + if line >= lineMax { // cannot represent line, use max. line so we have some information line = lineMax + // Drop column information if line number saturates. + // Ensures line+col is monotonic. See issue 51193. + col = 0 } if col > colMax { // cannot represent column, use max. column so we have some information diff --git a/src/cmd/internal/src/pos_test.go b/src/cmd/internal/src/pos_test.go index d4cd0e7ff1..cdf4ab4081 100644 --- a/src/cmd/internal/src/pos_test.go +++ b/src/cmd/internal/src/pos_test.go @@ -140,8 +140,8 @@ func TestLico(t *testing.T) { {makeLico(1, 0), ":1", 1, 0}, {makeLico(1, 1), ":1:1", 1, 1}, {makeLico(2, 3), ":2:3", 2, 3}, - {makeLico(lineMax, 1), fmt.Sprintf(":%d:1", lineMax), lineMax, 1}, - {makeLico(lineMax+1, 1), fmt.Sprintf(":%d:1", lineMax), lineMax, 1}, // line too large, stick with max. line + {makeLico(lineMax, 1), fmt.Sprintf(":%d", lineMax), lineMax, 1}, + {makeLico(lineMax+1, 1), fmt.Sprintf(":%d", lineMax), lineMax, 1}, // line too large, stick with max. line {makeLico(1, colMax), ":1", 1, colMax}, {makeLico(1, colMax+1), ":1", 1, 0}, // column too large {makeLico(lineMax+1, colMax+1), fmt.Sprintf(":%d", lineMax), lineMax, 0}, @@ -170,8 +170,8 @@ func TestIsStmt(t *testing.T) { {makeLico(1, 1), ":1:1" + def, 1, 1}, {makeLico(1, 1).withIsStmt(), ":1:1" + is, 1, 1}, {makeLico(1, 1).withNotStmt(), ":1:1" + not, 1, 1}, - {makeLico(lineMax, 1), fmt.Sprintf(":%d:1", lineMax) + def, lineMax, 1}, - {makeLico(lineMax+1, 1), fmt.Sprintf(":%d:1", lineMax) + def, lineMax, 1}, // line too large, stick with max. line + {makeLico(lineMax, 1), fmt.Sprintf(":%d", lineMax) + def, lineMax, 1}, + {makeLico(lineMax+1, 1), fmt.Sprintf(":%d", lineMax) + def, lineMax, 1}, // line too large, stick with max. line {makeLico(1, colMax), ":1" + def, 1, colMax}, {makeLico(1, colMax+1), ":1" + def, 1, 0}, // column too large {makeLico(lineMax+1, colMax+1), fmt.Sprintf(":%d", lineMax) + def, lineMax, 0}, @@ -214,9 +214,9 @@ func TestLogue(t *testing.T) { {makeLico(1, 1).withXlogue(PosPrologueEnd), ":1:1" + defs + pro, 1, 1}, {makeLico(1, 1).withXlogue(PosEpilogueBegin), ":1:1" + defs + epi, 1, 1}, - {makeLico(lineMax, 1).withXlogue(PosDefaultLogue), fmt.Sprintf(":%d:1", lineMax) + defs + defp, lineMax, 1}, - {makeLico(lineMax, 1).withXlogue(PosPrologueEnd), fmt.Sprintf(":%d:1", lineMax) + defs + pro, lineMax, 1}, - {makeLico(lineMax, 1).withXlogue(PosEpilogueBegin), fmt.Sprintf(":%d:1", lineMax) + defs + epi, lineMax, 1}, + {makeLico(lineMax, 1).withXlogue(PosDefaultLogue), fmt.Sprintf(":%d", lineMax) + defs + defp, lineMax, 1}, + {makeLico(lineMax, 1).withXlogue(PosPrologueEnd), fmt.Sprintf(":%d", lineMax) + defs + pro, lineMax, 1}, + {makeLico(lineMax, 1).withXlogue(PosEpilogueBegin), fmt.Sprintf(":%d", lineMax) + defs + epi, lineMax, 1}, } { x := test.x if got := formatstr("", x.Line(), x.Col(), true) + fmt.Sprintf(":%d:%d", x.IsStmt(), x.Xlogue()); got != test.string {