From 3ada42ffedf61343cc8a7cd7d6293bd646ecf3a6 Mon Sep 17 00:00:00 2001 From: Robert Griesemer Date: Thu, 20 Mar 2025 16:12:15 -0700 Subject: [PATCH] go/types, types2: align trace output a bit better for easier debugging Compute alignment padding rather than using a tab in trace output. This aligns the ":" after the file position in typical cases (files shorter than 1000 lines, lines shorter than 100 columns), resulting in nicer trace output for easier debugging. Before this CL (example trace): x.go:8:2: -- checking type A (white, objPath = ) x.go:8:11: . -- type B x.go:9:2: . . -- checking type B (white, objPath = A) x.go:9:14: . . . -- type C[D] x.go:9:13: . . . . -- instantiating type C with [D] x.go:9:13: . . . . . -- type C x.go:10:2: . . . . . . -- checking type C (white, objPath = A->B) x.go:10:6: . . . . . . . -- type any x.go:10:6: . . . . . . . => any (under = any) // *Alias x.go:10:11: . . . . . . . -- type struct{} x.go:10:11: . . . . . . . => struct{} // *Struct x.go:10:2: . . . . . . => type C[_ any] struct{} (black) With this CL: x.go:8:2 : -- checking type A (white, objPath = ) x.go:8:11 : . -- type B x.go:9:2 : . . -- checking type B (white, objPath = A) x.go:9:14 : . . . -- type C[D] x.go:9:13 : . . . . -- instantiating type C with [D] x.go:9:13 : . . . . . -- type C x.go:10:2 : . . . . . . -- checking type C (white, objPath = A->B) x.go:10:6 : . . . . . . . -- type any x.go:10:6 : . . . . . . . => any (under = any) // *Alias x.go:10:11 : . . . . . . . -- type struct{} x.go:10:11 : . . . . . . . => struct{} // *Struct x.go:10:2 : . . . . . . => type C[_ any] struct{} (black) Change-Id: Ibcf346737f57ec5351d1e1e65178e2c3c155d766 Reviewed-on: https://go-review.googlesource.com/c/go/+/659755 Auto-Submit: Robert Griesemer Reviewed-by: Robert Findley Reviewed-by: Robert Griesemer LUCI-TryBot-Result: Go LUCI --- src/cmd/compile/internal/types2/format.go | 21 ++++++++++++++++++- src/go/types/format.go | 25 +++++++++++++++++++++-- 2 files changed, 43 insertions(+), 3 deletions(-) diff --git a/src/cmd/compile/internal/types2/format.go b/src/cmd/compile/internal/types2/format.go index 442d219d1a..b61dfda1c8 100644 --- a/src/cmd/compile/internal/types2/format.go +++ b/src/cmd/compile/internal/types2/format.go @@ -88,13 +88,32 @@ func (check *Checker) sprintf(format string, args ...any) string { } func (check *Checker) trace(pos syntax.Pos, format string, args ...any) { - fmt.Printf("%s:\t%s%s\n", + // Use the width of line and pos values to align the ":" by adding padding before it. + // Cap padding at 5: 3 digits for the line, 2 digits for the column number, which is + // ok for most cases. + w := ndigits(pos.Line()) + ndigits(pos.Col()) + pad := " "[:max(5-w, 0)] + fmt.Printf("%s%s: %s%s\n", pos, + pad, strings.Repeat(". ", check.indent), sprintf(check.qualifier, true, format, args...), ) } +// ndigits returns the number of decimal digits in x. +// For x > 100, the result is always 3. +func ndigits(x uint) int { + switch { + case x < 10: + return 1 + case x < 100: + return 2 + default: + return 3 + } +} + // dump is only needed for debugging func (check *Checker) dump(format string, args ...any) { fmt.Println(sprintf(check.qualifier, true, format, args...)) diff --git a/src/go/types/format.go b/src/go/types/format.go index 09e599c3c3..550d22f5ae 100644 --- a/src/go/types/format.go +++ b/src/go/types/format.go @@ -88,13 +88,34 @@ func (check *Checker) sprintf(format string, args ...any) string { } func (check *Checker) trace(pos token.Pos, format string, args ...any) { - fmt.Printf("%s:\t%s%s\n", - check.fset.Position(pos), + pos1 := check.fset.Position(pos) + // Use the width of line and pos values to align the ":" by adding padding before it. + // Cap padding at 5: 3 digits for the line, 2 digits for the column number, which is + // ok for most cases. + w := ndigits(pos1.Line) + ndigits(pos1.Column) + pad := " "[:max(5-w, 0)] + fmt.Printf("%s%s: %s%s\n", + pos1, + pad, strings.Repeat(". ", check.indent), sprintf(check.fset, check.qualifier, true, format, args...), ) } +// ndigits returns the number of decimal digits in x. +// For x < 10, the result is always 1. +// For x > 100, the result is always 3. +func ndigits(x int) int { + switch { + case x < 10: + return 1 + case x < 100: + return 2 + default: + return 3 + } +} + // dump is only needed for debugging func (check *Checker) dump(format string, args ...any) { fmt.Println(sprintf(check.fset, check.qualifier, true, format, args...)) -- 2.50.0