environment variables work in a similar way for C++ code.

# Go references to C

Within the Go file, C's struct field names that are keywords in Go
can be accessed by prefixing them with an underscore: if x points at a C
struct with a field named "type", x._type accesses the field.
C struct fields that cannot be expressed in Go, such as bit fields
or misaligned data, are omitted in the Go struct, replaced by

			}
			// Invent new Name for the two-result function.
			n := f.Name["2"+r.Name.Go]
			if n == nil {
				n = new(Name)
				*n = *r.Name
				n.AddError = true
				n.Mangle = "_C2func_" + n.Go
				f.Name["2"+r.Name.Go] = n
			}
			expr = getNewIdent(n.Mangle)
			r.Name = n
			break
		}
	case ctxExpr:
		switch r.Name.Kind {
		case "func":
			if builtinDefs[r.Name.C] != "" {

	entryNames := []string{`/`, `//`, `\`, `/test.txt`}
	var names []string
	for _, f := range r.File {
		names = append(names, f.Name)
		if _, err := f.Open(); err != nil {
			t.Errorf("Error opening %q: %v", f.Name, err)
		}
		if _, err := r.Open(f.Name); err == nil {
			t.Errorf("Opening %q with fs.FS API succeeded", f.Name)
		}
	}
	if !reflect.DeepEqual(names, entryNames) {

		return
	}
	if goname == "malloc" {
		goname = "_CMalloc"
	}
	name := f.Name[goname]
	if name == nil {
		name = &Name{
			Go: goname,
		}
		f.Name[goname] = name
		f.NamePos[name] = sel.Pos()
	}
	f.Ref = append(f.Ref, &Ref{
		Name:    name,
		Expr:    n,
		Context: context,
	})
}

// Save calls to C.xxx for later processing.

struct {
	T1        // field name is T1
	*T2       // field name is T2
	P.T3      // field name is T3
	*P.T4     // field name is T4
	x, y int  // field names are x and y
}
</pre>

<p>
The following declaration is illegal because field names must be unique
in a struct type:
</p>

<pre>
struct {
	T     // conflicts with embedded field *T and *P.T

		return arm.C_SCOND_NONE, true
	}
	names := strings.Split(cond, ".")
	bits := uint8(0)
	for _, name := range names {
		if b, present := ls[name]; present {
			bits |= b
			continue
		}
		if b, present := scond[name]; present {
			bits = (bits &^ arm.C_SCOND) | b
			continue
		}
		return 0, false
	}
	return bits, true
}

func armRegisterNumber(name string, n int16) (int16, bool) {

// RET
//
//	LRETRN	comma // asm doesn't support the trailing comma.
//	{
//		outcode(int($1), &nullgen, 0, &nullgen);
//	}
	SYSCALL
	BEQ	R1, 2(PC)
	RET


// More JMP/JAL cases, and canonical names JMP, CALL.

	JAL	foo(SB) // CALL foo(SB)
	BEQ	R1, 2(PC)
	JMP	foo(SB)
	CALL	foo(SB)
	RET	foo(SB)

	// unary operation
	NEGW	R1, R2 // 00011023
	NEGV	R1, R2 // 0001102f

		w.emitf("type %s = %s", name, w.typeString(typ))
		return
	}
	if tparams := obj.Type().(*types.Named).TypeParams(); tparams != nil {
		var buf bytes.Buffer
		buf.WriteString(name)
		w.writeTypeParams(&buf, tparams, true)
		name = buf.String()
	}
	switch typ := typ.Underlying().(type) {
	case *types.Struct:
		w.emitStructType(name, typ)
	case *types.Interface:
		w.emitIfaceType(name, typ)

	var buf bytes.Buffer
	tw := tar.NewWriter(&buf)
	var files = []struct {
		Name, Body string
	}{
		{"readme.txt", "This archive contains some text files."},
		{"gopher.txt", "Gopher names:\nGeorge\nGeoffrey\nGonzo"},
		{"todo.txt", "Get animal handling license."},
	}
	for _, file := range files {
		hdr := &tar.Header{
			Name: file.Name,
			Mode: 0600,
			Size: int64(len(file.Body)),
		}

		}
		// In module mode, this package has a fully-qualified import path.
		// Remove it if present.
		fname = strings.TrimPrefix(fname, "cmd/cgo/internal/")

		namei := ""
		if i < len(name) {
			namei = name[i]
		}
		if fname != namei {
			t.Errorf("stk[%d] = %q, want %q", i, fname, namei)
		}
	}
}

func testPanicFromC(t *testing.T) {
	defer func() {
		r := recover()