From c112289ee4141ebc31db50328c355b01278b987b Mon Sep 17 00:00:00 2001
From: David Chase <drchase@google.com>
Date: Fri, 17 Jan 2020 12:03:55 -0500
Subject: [PATCH] cmd/compile: change the "bogus line" to be 1

The previous value was "too bogus" and caused objdump to crash.
Updated infinite loop test results (only run if -args -f) in ssa/debug_test.go
Probably also fixes #36621 but that bug needs more info to tell for certain.

Fixes #36570

Change-Id: I51144641d25d559308a98d726d87806bd340cc5a
Reviewed-on: https://go-review.googlesource.com/c/go/+/215297
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
---
 .../compile/internal/ssa/testdata/infloop.dlv-opt.nexts   | 8 ++++----
 src/cmd/internal/src/pos.go                               | 2 +-
 src/cmd/objdump/testdata/fmthello.go                      | 6 ++++++
 3 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/src/cmd/compile/internal/ssa/testdata/infloop.dlv-opt.nexts b/src/cmd/compile/internal/ssa/testdata/infloop.dlv-opt.nexts
index 19496de660..0b9f06f85d 100644
--- a/src/cmd/compile/internal/ssa/testdata/infloop.dlv-opt.nexts
+++ b/src/cmd/compile/internal/ssa/testdata/infloop.dlv-opt.nexts
@@ -2,11 +2,11 @@
 6:	func test() {
 8:		go func() {}()
 10:		for {
-1048575:
+1:	package main
 10:		for {
-1048575:
+1:	package main
 10:		for {
-1048575:
+1:	package main
 10:		for {
-1048575:
+1:	package main
 10:		for {
diff --git a/src/cmd/internal/src/pos.go b/src/cmd/internal/src/pos.go
index 60c7c91cde..861d9188b1 100644
--- a/src/cmd/internal/src/pos.go
+++ b/src/cmd/internal/src/pos.go
@@ -305,7 +305,7 @@ type lico uint32
 // because they have almost no interaction with other uses of the position.
 const (
 	lineBits, lineMax     = 20, 1<<lineBits - 2
-	bogusLine             = 1<<lineBits - 1 // Not a line number; used to disrupt infinite loops
+	bogusLine             = 1 // Used to disrupt infinite loops to prevent debugger looping
 	isStmtBits, isStmtMax = 2, 1<<isStmtBits - 1
 	xlogueBits, xlogueMax = 2, 1<<xlogueBits - 1
 	colBits, colMax       = 32 - lineBits - xlogueBits - isStmtBits, 1<<colBits - 1
diff --git a/src/cmd/objdump/testdata/fmthello.go b/src/cmd/objdump/testdata/fmthello.go
index e98268199d..fd16ebee1b 100644
--- a/src/cmd/objdump/testdata/fmthello.go
+++ b/src/cmd/objdump/testdata/fmthello.go
@@ -4,9 +4,15 @@ import "fmt"
 
 func main() {
 	Println("hello, world")
+	if flag {
+		for {
+		}
+	}
 }
 
 //go:noinline
 func Println(s string) {
 	fmt.Println(s)
 }
+
+var flag bool
-- 
2.50.0