x/tools/gopls: Rename Symbol incorrectly renames symbols when code contains a syntax error

[renthraysk]

Go version

go version go1.22.5 linux/amd64 & golang.org/x/tools/gopls v0.16.1

Output of go env in your module/workspace:

GO111MODULE=''
GOARCH='amd64'
GOBIN=''
GOCACHE='/home/ren/.cache/go-build'
GOENV='/home/ren/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMODCACHE='/home/ren/go/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/home/ren/go'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/usr/local/go'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.22.5'
GCCGO='gccgo'
GOAMD64='v1'
AR='ar'
CC='gcc'
CXX='g++'
CGO_ENABLED='1'
GOMOD='/home/ren/dev/experiments/http/go.mod'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build1814768367=/tmp/go-build -gno-record-gcc-switches'

What did you do?

Using Rename Symbol on the first attrs to rename to fhAttrs in the function below, results in the other usage of the symbol to be changed to afhAttrs0]

package main

import (
	"log/slog"
)

func Log(log *slog.Logger, buf []byte) {
	attrs := []slog.Attr{
		0:      {Key: "len"},
	}
	if len(buf) < 9 {
		log.
	}
	attrs[0].Value = slog.IntValue(len(buf))
}

What did you see happen?

package main

import (
	"log/slog"
)

func Log(log *slog.Logger, buf []byte) {
	fhAttrs := []slog.Attr{
		0:      {Key: "len"},
	}
	if len(buf) < 9 {
		log.
	}
	afhAttrs0].Value = slog.IntValue(len(buf))
}

What did you expect to see?

Either fail to rename the symbol due to the syntax error, or work as expected.

[gabyhelp]

Related Issues and Documentation

• x/tools/gopls: rename also renames qualified identifiers in a doc comment #44151
• x/tools/gopls: renaming a type is not allowed when it has the same name as a parameter #66150 (closed)
• x/tools/gopls: rename incorrectly renames multiple function definitions #62135
• x/tools/gopls: rename fails on struct method that references bad struct field #32882 (closed)
• x/tools/gopls: rename panics if a test file exists #33664 (closed)
• x/tools/gopls: type alias rename changes aliased type #61625 (closed)
• x/tools/gopls: rename things declared in other package fails #36743 (closed)
• x/tools/gopls: rename fails with "no object found" when the old identifier is missing a declaration #41851
• x/tools/gopls: crash during renaming #53277 (closed)
• x/tools/gopls: panic in textDocument.rename #39614 (closed)

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}

[hyangah]

Thanks for the report with the repro. I could reproduce the issue.
(Personally, I am surprised that rename works on sources in broken state :-))

gopls trace:

[Trace - 15:55:00.783 PM] Sending request 'textDocument/prepareRename - (39)'.
Params: {"textDocument":{"uri":"file:///Users/hakim/xx/main.go"},"position":{"line":7,"character":3}}


[Trace - 15:55:00.784 PM] Received response 'textDocument/prepareRename - (39)' in 0ms.
Result: {"range":{"start":{"line":7,"character":1},"end":{"line":7,"character":6}},"placeholder":"attrs"}
...

[Trace - 15:55:04.343 PM] Sending request 'textDocument/rename - (42)'.
Params: {"textDocument":{"uri":"file:///Users/hakim/xx/main.go"},"position":{"line":7,"character":3},"newName":"fhAttrs"}


[Trace - 15:55:04.344 PM] Received response 'textDocument/rename - (42)' in 0ms.
Result: {"documentChanges":[
{"textDocument":{
  "version":1,"uri":"file:///Users/hakim/xx/main.go"},
  "edits":[
     {"range":{"start":{"line":7,"character":1},"end":{"line":7,"character":6}},"newText":"fhAttrs"},
     {"range":{"start":{"line":13,"character":2},"end":{"line":13,"character":7}},"newText":"fhAttrs"}]}]}

[tttoad]

This is because the rename() function resolves this .

package main

import (
	"log/slog"
)

func Log(log *slog.Logger, buf []byte) {
	attrs := []slog.Attr{
		0:      {Key: "len"},
	}
	if len(buf) < 9 {
		log._   // Notice here. Added a placeholder.
	}
	attrs[0].Value = slog.IntValue(len(buf))
}

The protocol.NewMapper() function reads the original file without placeholders.

package main

import (
	"log/slog"
)

func Log(log *slog.Logger, buf []byte) {
	attrs := []slog.Attr{
		0:      {Key: "len"},
	}
	if len(buf) < 9 {
		log.
	}
	attrs[0].Value = slog.IntValue(len(buf))
}

[gopherbot]

Change https://go.dev/cl/599975 mentions this issue: gopls/rename: Fix rename failure when code contains syntax error.