go/types: Config.FakeImportC leaves gaps in type information but reports no error #76765
Description
This program (thanks to @znkr) reproduces a crash (see below) in the satisfy pass used by the printf analyzer. (Googlers: see b/466322822 for the internal bug report.) The failing syntax is the C.intFunc selector.
package printf_test
import (
"go/ast"
"go/importer"
"go/parser"
"go/token"
"go/types"
"testing"
"golang.org/x/tools/go/analysis"
"golang.org/x/tools/go/analysis/passes/inspect"
"golang.org/x/tools/go/analysis/passes/printf"
"golang.org/x/tools/go/ast/inspector"
)
func TestFakeCgoCrash(t *testing.T) {
const src = `package a
// typedef int (*intFunc) ();
//
// int
// bridge_int_func(intFunc f)
// {
// return f();
// }
//
// int fortytwo()
// {
// return 42;
// }
import "C"
import "fmt"
type Formatter struct {
Prefix string
}
func Foo(fo Formatter) {
f := C.intFunc(C.fortytwo)
fmt.Printf("%d %s\n", fo.Prefix, int(C.bridge_int_func(f)))
}
`
fset := token.NewFileSet()
f, err := parser.ParseFile(fset, "a.go", src, parser.Mode(0))
if err != nil {
t.Fatal(err)
}
info := types.Info{
Types: make(map[ast.Expr]types.TypeAndValue),
Defs: make(map[*ast.Ident]types.Object),
Uses: make(map[*ast.Ident]types.Object),
Implicits: make(map[ast.Node]types.Object),
Selections: make(map[*ast.SelectorExpr]*types.Selection),
Scopes: make(map[ast.Node]*types.Scope),
}
conf := types.Config{
Importer: importer.Default(),
FakeImportC: true,
}
pkg, err := conf.Check("a", fset, []*ast.File{f}, &info)
if err != nil {
t.Fatal(err)
}
inspectRes := inspector.New([]*ast.File{f})
pass := &analysis.Pass{
Analyzer: printf.Analyzer,
Fset: fset,
Files: []*ast.File{f},
Pkg: pkg,
TypesInfo: &info,
ResultOf: map[*analysis.Analyzer]interface{}{
inspect.Analyzer: inspectRes,
},
Report: func(d analysis.Diagnostic) {
// ignore reports
},
}
_, err = printf.Analyzer.Run(pass)
if err != nil {
t.Fatalf("Analyzer.Run failed: %v", err)
}
}goroutine 5 [running]:
testing.tRunner.func1.2({0x102a3e660, 0x102ada330})
/Users/adonovan/w/goroot/src/testing/testing.go:1967 +0x1a0
testing.tRunner.func1()
/Users/adonovan/w/goroot/src/testing/testing.go:1970 +0x318
panic({0x102a3e660?, 0x102ada330?})
/Users/adonovan/w/goroot/src/runtime/panic.go:860 +0x12c
golang.org/x/tools/refactor/satisfy.(*Finder).expr(0x68359b1ec030, {0x102aaf628, 0x68359af130f8})
/Users/adonovan/x/tools/refactor/satisfy/find.go:401 +0x3fc
golang.org/x/tools/refactor/satisfy.(*Finder).expr(0x68359b1ec030, {0x102aaf748, 0x68359b084080})
/Users/adonovan/x/tools/refactor/satisfy/find.go:464 +0x96c
golang.org/x/tools/refactor/satisfy.(*Finder).stmt(0x68359b1ec030, {0x102aafce8?, 0x68359b0840c0})
/Users/adonovan/x/tools/refactor/satisfy/find.go:540 +0xc30
golang.org/x/tools/refactor/satisfy.(*Finder).stmt(0x68359b1ec030, {0x102aafe08?, 0x68359b03af90})
/Users/adonovan/x/tools/refactor/satisfy/find.go:590 +0x7e4
golang.org/x/tools/refactor/satisfy.(*Finder).Find(0x68359b1ec030, 0x68359af16a80?, {0x68359af82bc8, 0x1, 0x68359afadec0?})
/Users/adonovan/x/tools/refactor/satisfy/find.go:106 +0x190
golang.org/x/tools/go/analysis/passes/printf.methodImplementations(0x68359b1ea000)
case *ast.SelectorExpr:
if _, ok := f.info.Selections[e]; ok {
f.expr(e.X) // selection
} else {
return f.info.Uses[e.Sel].Type() // qualified identifier <--------- SEGV calling nil.Type
}