x/tools/internal/refactor/inline: nil deref in (*freeVisitor).declare

[adonovan]

@mknyszek encountered this while running our benchmarks.

panic: runtime error: invalid memory address or nil pointer dereference [recovered, reraised]
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x8c5fa5]

goroutine 2256 [running]:
golang.org/x/tools/gopls/internal/cache.(*action).exec.func7.1()
    /home/swarming/.swarming/w/ir/repos/tools/gopls/internal/cache/analysis.go:1200 +0x233
panic({0x10ba780?, 0x1d283b0?})
    /home/swarming/.swarming/w/ir/go/src/runtime/panic.go:783 +0x132
golang.org/x/tools/internal/refactor/inline.(*freeVisitor).declare(...)
    /home/swarming/.swarming/w/ir/repos/tools/internal/refactor/inline/free.go:373
golang.org/x/tools/internal/refactor/inline.(*freeVisitor).shortVarDecl(...)
    /home/swarming/.swarming/w/ir/repos/tools/internal/refactor/inline/free.go:327
golang.org/x/tools/internal/refactor/inline.(*freeVisitor).Visit(0xc00ad45db8, {0x1553808?, 0xc00ad1b240})
    /home/swarming/.swarming/w/ir/repos/tools/internal/refactor/inline/free.go:126 +0x20a5
go/ast.Walk({0x1551320?, 0xc00ad45db8?}, {0x1553808, 0xc00ad1b240})
    /home/swarming/.swarming/w/ir/go/src/go/ast/walk.go:34 +0x4c
golang.org/x/tools/internal/refactor/inline.freeishNames(0xc00ad57bc0, {0x1553808, 0xc00ad1b240}, 0x0)
    /home/swarming/.swarming/w/ir/repos/tools/internal/refactor/inline/free.go:38 +0x79
golang.org/x/tools/internal/refactor/inline.trimNewImports({0x0, 0x0, 0x9?}, {0x1553808, 0xc00ad1b240})
    /home/swarming/.swarming/w/ir/repos/tools/internal/refactor/inline/inline.go:564 +0x5b
golang.org/x/tools/internal/refactor/inline.(*state).inline(0xc009d95860)
    /home/swarming/.swarming/w/ir/repos/tools/internal/refactor/inline/inline.go:275 +0x82c
golang.org/x/tools/internal/refactor/inline.Inline(0xc009d0e300, 0xc00a650280, 0xc008a5cf30)
    /home/swarming/.swarming/w/ir/repos/tools/internal/refactor/inline/inline.go:84 +0x96
golang.org/x/tools/internal/gofix.(*analyzer).inlineCall(0xc00ad16340, 0xc00a9f3f40, {0xc0002f3a88?, 0x1164500?})
    /home/swarming/.swarming/w/ir/repos/tools/internal/gofix/gofix.go:273 +0x30d
golang.org/x/tools/internal/gofix.(*analyzer).inline-range1({0xc0002f3a88?, 0x798185?})
    /home/swarming/.swarming/w/ir/repos/tools/internal/gofix/gofix.go:229 +0x167
golang.org/x/tools/internal/astutil/cursor.Cursor.Preorder.func1(0xc00ad090b0)
    /home/swarming/.swarming/w/ir/repos/tools/internal/astutil/cursor/cursor.go:129 +0xaf
golang.org/x/tools/internal/gofix.(*analyzer).inline(0xc00ad16340)
    /home/swarming/.swarming/w/ir/repos/tools/internal/gofix/gofix.go:226 +0xe2
golang.org/x/tools/internal/gofix.run(0xc0096a69a0, 0x1)
    /home/swarming/.swarming/w/ir/repos/tools/internal/gofix/gofix.go:84 +0x127
golang.org/x/tools/internal/gofix.init.func1(0x4792d9?)
    /home/swarming/.swarming/w/ir/repos/tools/internal/gofix/gofix.go:38 +0x18
golang.org/x/tools/gopls/internal/cache.(*action).exec.func7(0x1d49de0, 0xc009d95d48, 0xc0096a69a0, 0xc009d95d10)
    /home/swarming/.swarming/w/ir/repos/tools/gopls/internal/cache/analysis.go:1213 +0x97
golang.org/x/tools/gopls/internal/cache.(*action).exec(0xc008f70870, {0x15587e0, 0xc008345350})
    /home/swarming/.swarming/w/ir/repos/tools/gopls/internal/cache/analysis.go:1214 +0xb34
golang.org/x/tools/gopls/internal/cache.execActions.func1.1()
    /home/swarming/.swarming/w/ir/repos/tools/gopls/internal/cache/analysis.go:908 +0x52
sync.(*Once).doSlow(0x0?, 0xc346c0?)
    /home/swarming/.swarming/w/ir/go/src/sync/once.go:78 +0xab
sync.(*Once).Do(...)
    /home/swarming/.swarming/w/ir/go/src/sync/once.go:69
golang.org/x/tools/gopls/internal/cache.execActions.func1()
    /home/swarming/.swarming/w/ir/repos/tools/gopls/internal/cache/analysis.go:906 +0x85
created by golang.org/x/tools/gopls/internal/cache.execActions in goroutine 1740
    /home/swarming/.swarming/w/ir/repos/tools/gopls/internal/cache/analysis.go:904 +0x55
2025/04/10 20:03:51 gopls invocation failed with error: exit status 2
exit status 1
FAIL    golang.org/x/tools/gopls/internal/test/integration/bench    1.267s
FAIL

[gabyhelp]

Related Issues

• x/tools/internal/analysisinternal: panic in IsTypeNamed #71456 (closed)
• go/types: SIGSEGV in (*Checker).exprInternal #37602
• x/tools/gopls: Highlight: nil deref panic on CompositeLiteral with no type #68918 (closed)
• x/tools/gopls: InlayHint: nil panic due to ast.CallExpr.Fun with no type #67142 (closed)
• x/tools/gopls: invalid memory address or nil pointer dereference on highlight #68927 (closed)
• x/tools/go/packages: nil pointer dereference #69524 (closed)
• x/tools/gopls: crash in testFuncs with *error argument #70927 (closed)
• x/tools/gopls/internal/regtest/workspace: unrecognized failures #59080 (closed)
• x/tools/gopls: panic because of nil pointer in cache.fileWasSaved #37687 (closed)
• x/tools/internal/imports: invalid memory address or nil pointer dereference (crash) #57622 (closed)

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

[gopherbot]

Change https://go.dev/cl/665776 mentions this issue: internal/refactor/inline: freeishNames initial scope