internal/refactor/inline: "args/params mismatch" panic (reported by telemetry)

[adonovan]

This stack u0ujVg was reported by telemetry:

gopls/bug
golang.org/x/tools/gopls/internal/bug.report:35
golang.org/x/tools/gopls/internal/bug.Errorf:2
golang.org/x/tools/gopls/internal/lsp/source.inlineCall.func2:2
runtime.gopanic:88
golang.org/x/tools/internal/refactor/inline.assert:?2133
golang.org/x/tools/internal/refactor/inline.createBindingDecl:77
golang.org/x/tools/internal/refactor/inline.inline:345
golang.org/x/tools/internal/refactor/inline.Inline:15
golang.org/x/tools/gopls/internal/lsp/source.inlineCall:64
golang.org/x/tools/gopls/internal/lsp/source.ApplyFix:5
golang.org/x/tools/gopls/internal/lsp.(*commandHandler).ApplyFix.func1:1
golang.org/x/tools/gopls/internal/lsp.(*commandHandler).run.func1:2
golang.org/x/tools/gopls/internal/lsp.(*commandHandler).run:72
golang.org/x/tools/gopls/internal/lsp.(*commandHandler).ApplyFix:1
golang.org/x/tools/gopls/internal/lsp/command.Dispatch:25
golang.org/x/tools/gopls/internal/lsp.(*Server).executeCommand:19

golang.org/x/tools/gopls@v0.14.2 go1.21.3 darwin/arm64 (1)

createBindingDecl:77 is

	assert(len(values) == 0, "args/params mismatch")

The stack indicates that this refactoring was applied to ill-typed code (hence the recover in source.inlineCall), and the inliner is generally not robust against ill-typed inputs. So potentially this is working as intended, though we should investigate first.

Issue created by golang.org/x/tools/gopls/internal/telemetry/cmd/stacks.

[adonovan]

Easily reproduced at master:

xtools$ #go run ./gopls bug  #  fix -a ./a.go:#28 refactor.inline
xtools$ cat a.go
package tools

func f() {
	g(1, 2)
}

func g(x int) {
}

xtools$ go run ./gopls fix -a ./a.go:#28 refactor.inline
Log: Loading packages...
Info: Finished loading packages.
Log: Running...
Info: completed
gopls: inlining failed unexpectedly: args/params mismatch
...huge ugly "stack: [...bytes...]" message redacted...
exit status 2

xtools$ xtools$ go run ./gopls bug
-- 2023-12-11 13:34:42.009829 -0500 EST -- 
/Users/adonovan/w/xtools/gopls/internal/lsp/source/inline.go:101: inlining failed unexpectedly: args/params mismatch
...same huge ugly "stack: [...bytes...]" message redacted
goroutine 1 [running]:
runtime/debug.Stack()
	/Users/adonovan/w/homebrew/Cellar/go/1.21.3/libexec/src/runtime/debug/stack.go:24 +0x64
golang.org/x/tools/gopls/internal/util/bug.report({0x14002ba7800, 0x3547})
	/Users/adonovan/w/xtools/gopls/internal/util/bug/bug.go:88 +0xd4
golang.org/x/tools/gopls/internal/util/bug.Errorf({0x104ee7393?, 0xf3d?}, {0x140039dfbc8?, 0x10460f898?, 0x14002785d90?})
	/Users/adonovan/w/xtools/gopls/internal/util/bug/bug.go:58 +0x3c
golang.org/x/tools/gopls/internal/lsp/source.inlineCall.func2()
	/Users/adonovan/w/xtools/gopls/internal/lsp/source/inline.go:101 +0x84
panic({0x1051d0480?, 0x1400401f340?})
	/Users/adonovan/w/homebrew/Cellar/go/1.21.3/libexec/src/runtime/panic.go:914 +0x218
golang.org/x/tools/internal/refactor/inline.assert(...)
	/Users/adonovan/w/xtools/internal/refactor/inline/inline.go:2133
golang.org/x/tools/internal/refactor/inline.createBindingDecl(0x1053465b0, 0x14004032240, {0x1400401f290?, 0x2, 0x0?}, 0x14004003920, {0x0, 0x0, 0x1400403e050?})
...

[gopherbot]

Change https://go.dev/cl/548736 mentions this issue: gopls/internal/lsp/source: forgive inliner failures in illtyped code