Skip to content

/ go

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

cmd/compile: struct literals with dot-imported key identifiers mishandled #43164

Open
mdempsky opened this issue Dec 13, 2020 · 1 comment
Open

cmd/compile: struct literals with dot-imported key identifiers mishandled #43164

mdempsky opened this issue Dec 13, 2020 · 1 comment
Assignees
@mdempsky
Labels
NeedsFix
Milestone
Go1.17

Comments

@mdempsky
Copy link
Member

@mdempsky mdempsky commented Dec 13, 2020

In type-check, we have code that tries to recognize when a bare identifier was rewritten due to a dot-imported package, but it fails when the same symbol is dot-imported as two different in packages in separate compilation units.

This program should compile successfully, and is accepted by go/types and gccgo, but not cmd/compile: https://play.golang.org/p/to-v3A3bFt-
@mdempsky mdempsky added the NeedsFix label Dec 13, 2020
@mdempsky mdempsky added this to the Go1.17 milestone Dec 13, 2020
@mdempsky mdempsky self-assigned this Dec 13, 2020
@gopherbot
Copy link

@gopherbot gopherbot commented Dec 14, 2020

Change https://golang.org/cl/277713 mentions this issue: [dev.regabi] cmd/compile: use ir.Ident for imported identifiers
gopherbot pushed a commit that referenced this issue Dec 15, 2020
@mdempsky
[dev.regabi] cmd/compile: use ir.Ident for imported identifiers
4c2d66f 
This CL substantially reworks how imported declarations are handled,
and fixes a number of issues with dot imports. In particular:

1. It eliminates the stub ir.Name declarations that are created
upfront during import-declaration processing, allowing this to be
deferred to when the declarations are actually needed. (Eventually,
this can be deferred even further so we never have to create ir.Names
w/ ONONAME, but this CL is already invasive/subtle enough.)

2. During noding, we now use ir.Idents to represent uses of imported
declarations, including of dot-imported declarations.

3. Unused dot imports are now reported after type checking, so that we
can correctly distinguish whether composite literal keys are a simple
identifier (struct literals) or expressions (array/slice/map literals)
and whether it might be a use of a dot-imported declaration.

4. It changes the "redeclared" error messages to report the previous
position information in the same style as other compiler error
messages that reference other source lines.

Passes buildall w/ toolstash -cmp.

Fixes #6428.
Fixes #43164.
Fixes #43167.
Updates #42990.

Change-Id: I40a0a780ec40daf5700fbc3cfeeb7300e1055981
Reviewed-on: https://go-review.googlesource.com/c/go/+/277713
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Trust: Matthew Dempsky <mdempsky@google.com>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees

@mdempsky mdempsky

Labels
NeedsFix
Projects
None yet
Milestone
Go1.17
Linked pull requests

Successfully merging a pull request may close this issue.

None yet
2 participants
@mdempsky @gopherbot
You can’t perform that action at this time.