From: Than McIntosh <thanm@google.com>
Date: Mon, 13 Dec 2021 17:03:13 +0000 (-0500)
Subject: cmd/compile/internal/amd64: fix for coverage testing
X-Git-Tag: go1.18beta1~9
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=3e8aa5dd495d30ff29cd4fb78aabe8fc0ebb1eda;p=gostls13.git

cmd/compile/internal/amd64: fix for coverage testing

Fix up a unit test to make it more friendly for coverage runs.
Currently on tip if you do

   cd ${GOROOT}/src ; go test -cover cmd/compile/...

it will cause a failure in the TestGoAMD64v1 testpoint of
cmd/compile/internal/amd64, the reason being that this testpoint
copies and reruns the test executable, expecting the rerun to produce
only the output "PASS", whereas if "-cover" is used, the output will
include percentage of statements covered as well. To fix, rework the
test to tolerate additional output if coverage is enabled.

Change-Id: I2512e06ca06e5f38108f2891ff84276d148c4f9e
Reviewed-on: https://go-review.googlesource.com/c/go/+/371234
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
---

diff --git a/src/cmd/compile/internal/amd64/versions_test.go b/src/cmd/compile/internal/amd64/versions_test.go
index ee1a8ca3aa..7aa697b811 100644
--- a/src/cmd/compile/internal/amd64/versions_test.go
+++ b/src/cmd/compile/internal/amd64/versions_test.go
@@ -74,8 +74,18 @@ func TestGoAMD64v1(t *testing.T) {
 	if err != nil {
 		t.Fatalf("couldn't execute test: %s", err)
 	}
-	if string(out) != "PASS\n" {
-		t.Fatalf("test reported error: %s", string(out))
+	// Expect to see output of the form "PASS\n", unless the test binary
+	// was compiled for coverage (in which case there will be an extra line).
+	success := false
+	lines := strings.Split(string(out), "\n")
+	if len(lines) == 2 {
+		success = lines[0] == "PASS" && lines[1] == ""
+	} else if len(lines) == 3 {
+		success = lines[0] == "PASS" &&
+			strings.HasPrefix(lines[1], "coverage") && lines[2] == ""
+	}
+	if !success {
+		t.Fatalf("test reported error: %s lines=%+v", string(out), lines)
 	}
 }