cmd/compile: incorrect abstract origin assigned to param of inlined subroutine

[thanm]

Please answer these questions before submitting your issue. Thanks!

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

tip
go version devel +70f441bc49 Wed Dec 6 19:27:26 2017 +0000 linux/amd64

Does this issue reproduce with the latest release?

yes

What operating system and processor architecture are you using (go env)?

GOHOSTARCH="amd64"
GOHOSTOS="linux"

What did you do?

Compile this program:

Examine the generated DWARF for the inlined routine "cand". Both parameters share the same abstract origin, which should never happen.

 <3><3232c>: Abbrev Number: 17 (DW_TAG_formal_parameter)
    <3232d>   DW_AT_abstract_origin: <0x3229b>
    <32331>   DW_AT_location    : 2 byte block: 91 60 	(DW_OP_fbreg: -32)
 <3><32334>: Abbrev Number: 17 (DW_TAG_formal_parameter)
    <32335>   DW_AT_abstract_origin: <0x3229b>
    <32339>   DW_AT_location    : 2 byte block: 91 68 	(DW_OP_fbreg: -24)

A complete runnable program is good.
A link on play.golang.org is best.

What did you expect to see?

Different abstract origins.

What did you see instead?

Both params have abstract originl 0x3229b. The code that assigns it is buggy.

[thanm]

FYI, this bug will impact user experience in GDB, but will not cause any crashes or other unpleasant runtime behavior, just to be clear.

[gopherbot]

Change https://golang.org/cl/82396 mentions this issue: cmd/compile: fix bug in logic for computing var abstract origins

[cherrymui]

Compile this program:

The program seems missing...

[thanm]

Apologies-- "paste" apparently didn't go through. Here is the playground link:

https://play.golang.org/p/BIf78rGlOI