cmd/cover: internal error: overlapping blocks for func in for clause

[dvyukov]

I am on commit c754be8.

Add the following file:

$ cat src/cmd/internal/obj/arm64/arm64_test.go

package arm64
import "testing"
func TestTest(t *testing.T) {} 

Then:

$ go test -c -cover cmd/internal/obj/arm64
cover: internal error: block 60 overlaps block 62
    src/cmd/internal/obj/arm64/obj7.go:#8196,#8260 src/cmd/internal/obj/arm64/obj7.go:#8237,#8256

[robpike]

The contents of the added file above is irrelevant. Its only purpose, being the first test file in the directory, is to trigger the coverage rewrite.

Here is a self-contained simple example of the problem

% cat x.go
package x

func x() {
for ; ; (func() {})() {
}
}
% go tool cover -mode=set x.go > /dev/null
cover: internal error: block 0 overlaps block 1
x.go:#20,#45 x.go:#39,#41
%

[robpike]

closed by https://go-review.googlesource.com/8284