cmd/compile: reports wrong line number when calling a method in multiple lines

[yhuang0]

Please answer these questions before submitting your issue. Thanks!

What version of Go are you using (go version)?

go1.9

Does this issue reproduce with the latest release?

Yes

What did you do?

Use method to access array in struct.
https://play.golang.org/p/oJ_Uh9hGN0

What did you expect to see?

I expected the error in the stack trace to point to line 16.

What did you see instead?

Stack trace pointed to line 13 instead, the first invocation of Get()

[mvdan]

Reproduces on master.

Here's an interesting twist: https://play.golang.org/p/8G8BxckMZq

It seems to use the first method call as the position, so in the case above it uses the first GetB call, not the first GetA call. Probably the compiler recording the line number incorrectly, perhaps because it reuses something between these calls?

/cc @mdempsky

[gopherbot]

Change https://golang.org/cl/67470 mentions this issue: cmd/compile: Multiple invocations of an inlined function generate distinct panics

[ianlancetaylor]

An incorrect traceback can be very confusing, so marking this as a 1.9.1 candidate.

[gopherbot]

Change https://golang.org/cl/67632 mentions this issue: cmd/compile: fix merge rules for panic calls

[randall77]

Reopening for 1.9.1 (or 1.9.2?)