No Compiler Optimization Details for some files

[Kentzo]

What version of Go, VS Code & VS Code Go extension are you using?

Version Information

• Run go version to get version of Go from the VS Code integrated terminal.
  • go version go1.26.1 darwin/arm64
• Run gopls -v version to get version of Gopls from the VS Code integrated terminal.
  • golang.org/x/tools/gopls v0.21.1
• Run code -v or code-insiders -v to get version of VS Code or VS Code Insiders.
  • 1.115.0
• Check your installed extensions to get the version of the VS Code Go extension
  • 0.52.2
• Run Ctrl+Shift+P (Cmd+Shift+P on Mac OS) > Go: Locate Configured Go Tools command.

## Environment

GOBIN: /Users/kentzo/.local/bin
toolsGopath: 
gopath: /Users/kentzo/.local/share/go
GOROOT: /private/var/db/brew/homebrew/Cellar/go/1.26.1/libexec
PATH: /opt/homebrew/bin:/usr/local/bin:/System/Cryptexes/App/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/homebrew/sbin/:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/local/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/appleinternal/bin:/opt/X11/bin:/Library/Apple/usr/bin:/Applications/PyCharm CE.app/Contents/MacOS:/Applications/Sublime Text.app/Contents/SharedSupport/bin:/Applications/VMware Fusion.app/Contents/Public:/usr/local/sbin:/Users/kentzo/.local/bin

## Tools

	go:	/opt/homebrew/bin/go: go version go1.26.1 darwin/arm64

	gotests:	/Users/kentzo/.local/bin/gotests	(version: v1.6.0 built with go: go1.26.1)
	impl:	/Users/kentzo/.local/bin/impl	(version: v1.4.0 built with go: go1.26.1)
	goplay:	/Users/kentzo/.local/bin/goplay	(version: v1.0.0 built with go: go1.26.1)
	dlv:	/Users/kentzo/.local/bin/dlv	(version: v1.26.1 built with go: go1.26.1)
	golangci-lint-v2:	/Users/kentzo/.local/bin/golangci-lint-v2	(version: v2.11.4 built with go: go1.26.1)
	gopls:	/Users/kentzo/.local/bin/gopls	(version: v0.21.1 built with go: go1.26.1)

## Go env

Workspace Folder (CoreDNS): /Users/kentzo/Documents/Hobby/coredns-srp

	AR='ar'
	CC='cc'
	CGO_CFLAGS='-O2 -g'
	CGO_CPPFLAGS=''
	CGO_CXXFLAGS='-O2 -g'
	CGO_ENABLED='1'
	CGO_FFLAGS='-O2 -g'
	CGO_LDFLAGS='-O2 -g'
	CXX='c++'
	GCCGO='gccgo'
	GO111MODULE=''
	GOARCH='arm64'
	GOARM64='v8.0'
	GOAUTH='netrc'
	GOBIN='/Users/kentzo/.local/bin'
	GOCACHE='/Users/kentzo/.cache/go/build'
	GOCACHEPROG=''
	GODEBUG=''
	GOENV='/Users/kentzo/.config/go/env'
	GOEXE=''
	GOEXPERIMENT=''
	GOFIPS140='off'
	GOFLAGS=''
	GOGCCFLAGS='-fPIC -arch arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -ffile-prefix-map=/var/folders/g6/8p_5qmqj14xfwphqsx_6g4mh0000gn/T/go-build2543851414=/tmp/go-build -gno-record-gcc-switches -fno-common'
	GOHOSTARCH='arm64'
	GOHOSTOS='darwin'
	GOINSECURE=''
	GOMOD='/dev/null'
	GOMODCACHE='/Users/kentzo/.cache/go/mod'
	GONOPROXY=''
	GONOSUMDB=''
	GOOS='darwin'
	GOPATH='/Users/kentzo/.local/share/go'
	GOPRIVATE=''
	GOPROXY='https://proxy.golang.org,direct'
	GOROOT='/private/var/db/brew/homebrew/Cellar/go/1.26.1/libexec'
	GOSUMDB='sum.golang.org'
	GOTELEMETRY='local'
	GOTELEMETRYDIR='/Users/kentzo/Library/Application Support/go/telemetry'
	GOTMPDIR=''
	GOTOOLCHAIN='local+path'
	GOTOOLDIR='/private/var/db/brew/homebrew/Cellar/go/1.26.1/libexec/pkg/tool/darwin_arm64'
	GOVCS=''
	GOVERSION='go1.26.1'
	GOWORK=''
	PKG_CONFIG='pkg-config'

Share the Go related settings you have added/edited

User:

{
    "go.survey.prompt": false,
    "go.showWelcome": false,
    "go.inlayHints.ignoredError": true,
    "go.inlayHints.constantValues": true,
    "go.editorContextMenuCommands": {
        "compilerDetails": true
    },
    "go.inlayHints.compositeLiteralFields": true,
    "go.inlayHints.parameterNames": true,
    "go.coverOnSingleTest": true,
    "go.coverOnSingleTestFile": true,
    "go.testExplorer.showDynamicSubtestsInEditor": true,
}

Folder:

{
    "go.buildFlags": [
        "-v"
    ],
    "go.lintOnSave": "package",
    "go.lintTool": "golangci-lint-v2",
    "gopls": {
        "ui.semanticTokens": true,
    },
    "go.lintFlags": [
        "--path-mode=abs",
        "--enable=godox",
        "--enable=nilerr",
        "--enable=nilnil",
        "--enable=prealloc",
        "--enable=wastedassign",
        "--disable=godoclint"
    ],
    "go.toolsEnvVars": {
        "GOTOOLCHAIN": "local+path"
    },
    "go.testFlags": [
        "-race",
        "-shuffle=on"
    ]
}

Describe the bug

When I use "Go: Toggle compiler optimization details", some files in the package get both inline and escape hints while others get nothing.
As long as a given package can be build, I expect optimization details hints to be provided for all its files.

[madelinekalil]

Hello, thank you for the bug report. Will you please inspect/share some of the logs from the gopls trace output? Select the "Output" panel and on the right hand side select gopls. Search for "gopls.gc_details" and see if there's any errors following this command or if it successfully returns gc details. The results should come after "Received notification 'textDocument/publishDiagnostics'".

[Kentzo]

I modified the settings by adding:

"gopls": {
        "verboseOutput": true,
    },

Toggling "Go: Toggle compiler optimization details" does not generate any output in the "gopls" and "gopls (server)" outputs.

Is there a setting I should check to enable trace logging?

[madelinekalil]

Sorry for not specifying this, I believe "go.trace.server": "verbose", is what you need (not the gopls setting)

[Kentzo]

I further followed Collect gopls information and enabled "-rpc.trace" as well as "go.trace.server": "verbose". The output is attached.

Note that it mentions "msg.go" many times. However, VSCode shows none of those hints neither in Editor nor in Problems.

gopls.log

[Kentzo]

For some reason there was no "textDocument/publishDiagnostics" for this file.

[guillemus]

NOTE: I found this with codex. This might be wrong, but the same issue happened to me and it was solved by renaming the file.

The root cause might be a basename collision in compiler -gcflags=-json output.

Compiler code:

• writerForLSP strips directories and writes <basename>.json:
  https://github.com/golang/go/blob/ed1646a8ae43d151c81e144f031b7f37d7947d7d/src/cmd/compile/internal/logopt/log_opts.go#L383-L401
• FlushLoggedOpts switches on full source path, but reopens the JSON file with os.Create each time the file changes:
  https://github.com/golang/go/blob/ed1646a8ae43d151c81e144f031b7f37d7947d7d/src/cmd/compile/internal/logopt/log_opts.go#L432-L505
  So two distinct files like server/markdown.go and .../goldmark/markdown.go can both map to markdown.json, and the later one overwrites the earlier one.
  Then gopls reads the surviving JSON header path and filters diagnostics by requested directory:
• https://github.com/golang/tools/blob/1f392cc2b528d531aef4d3c89cb6fd512fa7c325/gopls/internal/golang/compileropt.go#L26-L82
• https://github.com/golang/tools/blob/1f392cc2b528d531aef4d3c89cb6fd512fa7c325/gopls/internal/golang/compileropt.go#L91-L166
  If the surviving markdown.json points at the dependency file, local markdown.go gets no diagnostics.
  Renaming my local file to a unique basename made the diagnostics appear immediately.

@Kentzo if you rename the file do you get diagnostics?

[madelinekalil]

@guillemus thanks for investigating! I can also reproduce: show compiler optimization details on two distinctly named files in different directories, then rename one to match the other. Compiler optimization details for one file now fail to appear

[Kentzo]

Renaming did not help in my case.

See golang/go#78700 (comment) for code I have this issue with.

[madelinekalil]

@Kentzo did you also toggle the command or restart the language server after renaming?

[Kentzo]

@Kentzo did you also toggle the command or restart the language server after renaming?

Renamed -> Restarted VSCode -> Toggled and re-Toggled.

[hyangah]

cc @dr2chase #4013 (comment)

[dr2chase]

I have not dug into the specific examples, but by default the compiler does not do what is claimed here. If I say (as I just did to verify this):

go build -gcflags=all=-json=0,`pwd`/logopts .

and then in look in directory logopts, I see a bunch of url.Pathescape'd package named directories, like internal%2Fruntime%2Fpprof%2Flabel
and those contain JSON files corresponding to the source files in that directory.

I'm curious what (series of) actual compiler invocations causes this.

Is it possible that we left these outputs out of the Go cache and it is not actually (re)running the compiler?