mirror of
https://github.com/golang/go
synced 2024-11-22 10:14:40 -07:00
go/types, types2: factor out code for type checking composite literals
Move code into separate function in separate file. Replace "goto Error" statements with "x.mode = invalid; return". No other semantic changes. Change-Id: I2d5e858e8df3dc1011fa79cdac3db9d3e7b1dfe5 Reviewed-on: https://go-review.googlesource.com/c/go/+/610556 Reviewed-by: Tim King <taking@google.com> Reviewed-by: Robert Griesemer <gri@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Auto-Submit: Robert Griesemer <gri@google.com>
This commit is contained in:
Robert Griesemer
Gopher Robot
parent
1e2114349d
commit
0fb35efe5b
@ -1150,235 +1150,11 @@ func (check *Checker) exprInternal(T *target, x *operand, e syntax.Expr, hint Ty
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}
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case *syntax.CompositeLit:
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var typ, base Type
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var isElem bool // true if composite literal is an element of an enclosing composite literal
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switch {
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case e.Type != nil:
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// composite literal type present - use it
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// [...]T array types may only appear with composite literals.
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// Check for them here so we don't have to handle ... in general.
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if atyp, _ := e.Type.(*syntax.ArrayType); atyp != nil && atyp.Len == nil {
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// We have an "open" [...]T array type.
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// Create a new ArrayType with unknown length (-1)
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// and finish setting it up after analyzing the literal.
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typ = &Array{len: -1, elem: check.varType(atyp.Elem)}
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base = typ
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break
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}
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typ = check.typ(e.Type)
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base = typ
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case hint != nil:
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// no composite literal type present - use hint (element type of enclosing type)
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typ = hint
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base = typ
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// *T implies &T{}
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if b, ok := deref(coreType(base)); ok {
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base = b
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}
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isElem = true
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default:
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// TODO(gri) provide better error messages depending on context
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check.error(e, UntypedLit, "missing type in composite literal")
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check.compositeLit(T, x, e, hint)
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if x.mode == invalid {
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goto Error
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}
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switch utyp := coreType(base).(type) {
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case *Struct:
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// Prevent crash if the struct referred to is not yet set up.
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// See analogous comment for *Array.
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if utyp.fields == nil {
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check.error(e, InvalidTypeCycle, "invalid recursive type")
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goto Error
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}
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if len(e.ElemList) == 0 {
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break
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}
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// Convention for error messages on invalid struct literals:
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// we mention the struct type only if it clarifies the error
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// (e.g., a duplicate field error doesn't need the struct type).
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fields := utyp.fields
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if _, ok := e.ElemList[0].(*syntax.KeyValueExpr); ok {
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// all elements must have keys
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visited := make([]bool, len(fields))
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for _, e := range e.ElemList {
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kv, _ := e.(*syntax.KeyValueExpr)
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if kv == nil {
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check.error(e, MixedStructLit, "mixture of field:value and value elements in struct literal")
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continue
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}
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key, _ := kv.Key.(*syntax.Name)
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// do all possible checks early (before exiting due to errors)
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// so we don't drop information on the floor
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check.expr(nil, x, kv.Value)
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if key == nil {
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check.errorf(kv, InvalidLitField, "invalid field name %s in struct literal", kv.Key)
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continue
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}
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i := fieldIndex(fields, check.pkg, key.Value, false)
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if i < 0 {
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var alt Object
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if j := fieldIndex(fields, check.pkg, key.Value, true); j >= 0 {
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alt = fields[j]
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}
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msg := check.lookupError(base, key.Value, alt, true)
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check.error(kv.Key, MissingLitField, msg)
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continue
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}
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fld := fields[i]
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check.recordUse(key, fld)
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etyp := fld.typ
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check.assignment(x, etyp, "struct literal")
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// 0 <= i < len(fields)
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if visited[i] {
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check.errorf(kv, DuplicateLitField, "duplicate field name %s in struct literal", key.Value)
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continue
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}
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visited[i] = true
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}
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} else {
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// no element must have a key
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for i, e := range e.ElemList {
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if kv, _ := e.(*syntax.KeyValueExpr); kv != nil {
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check.error(kv, MixedStructLit, "mixture of field:value and value elements in struct literal")
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continue
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}
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check.expr(nil, x, e)
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if i >= len(fields) {
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check.errorf(x, InvalidStructLit, "too many values in struct literal of type %s", base)
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break // cannot continue
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}
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// i < len(fields)
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fld := fields[i]
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if !fld.Exported() && fld.pkg != check.pkg {
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check.errorf(x, UnexportedLitField, "implicit assignment to unexported field %s in struct literal of type %s", fld.name, base)
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continue
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}
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etyp := fld.typ
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check.assignment(x, etyp, "struct literal")
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}
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if len(e.ElemList) < len(fields) {
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check.errorf(e.Rbrace, InvalidStructLit, "too few values in struct literal of type %s", base)
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// ok to continue
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}
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}
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case *Array:
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// Prevent crash if the array referred to is not yet set up. Was go.dev/issue/18643.
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// This is a stop-gap solution. Should use Checker.objPath to report entire
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// path starting with earliest declaration in the source. TODO(gri) fix this.
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if utyp.elem == nil {
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check.error(e, InvalidTypeCycle, "invalid recursive type")
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goto Error
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}
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n := check.indexedElts(e.ElemList, utyp.elem, utyp.len)
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// If we have an array of unknown length (usually [...]T arrays, but also
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// arrays [n]T where n is invalid) set the length now that we know it and
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// record the type for the array (usually done by check.typ which is not
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// called for [...]T). We handle [...]T arrays and arrays with invalid
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// length the same here because it makes sense to "guess" the length for
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// the latter if we have a composite literal; e.g. for [n]int{1, 2, 3}
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// where n is invalid for some reason, it seems fair to assume it should
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// be 3 (see also Checked.arrayLength and go.dev/issue/27346).
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if utyp.len < 0 {
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utyp.len = n
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// e.Type is missing if we have a composite literal element
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// that is itself a composite literal with omitted type. In
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// that case there is nothing to record (there is no type in
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// the source at that point).
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if e.Type != nil {
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check.recordTypeAndValue(e.Type, typexpr, utyp, nil)
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}
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}
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case *Slice:
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// Prevent crash if the slice referred to is not yet set up.
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// See analogous comment for *Array.
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if utyp.elem == nil {
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check.error(e, InvalidTypeCycle, "invalid recursive type")
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goto Error
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}
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check.indexedElts(e.ElemList, utyp.elem, -1)
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case *Map:
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// Prevent crash if the map referred to is not yet set up.
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// See analogous comment for *Array.
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if utyp.key == nil || utyp.elem == nil {
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check.error(e, InvalidTypeCycle, "invalid recursive type")
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goto Error
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}
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// If the map key type is an interface (but not a type parameter),
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// the type of a constant key must be considered when checking for
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// duplicates.
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keyIsInterface := isNonTypeParamInterface(utyp.key)
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visited := make(map[interface{}][]Type, len(e.ElemList))
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for _, e := range e.ElemList {
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kv, _ := e.(*syntax.KeyValueExpr)
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if kv == nil {
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check.error(e, MissingLitKey, "missing key in map literal")
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continue
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}
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check.exprWithHint(x, kv.Key, utyp.key)
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check.assignment(x, utyp.key, "map literal")
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if x.mode == invalid {
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continue
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}
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if x.mode == constant_ {
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duplicate := false
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xkey := keyVal(x.val)
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if keyIsInterface {
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for _, vtyp := range visited[xkey] {
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if Identical(vtyp, x.typ) {
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duplicate = true
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break
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}
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}
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visited[xkey] = append(visited[xkey], x.typ)
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} else {
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_, duplicate = visited[xkey]
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visited[xkey] = nil
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}
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if duplicate {
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check.errorf(x, DuplicateLitKey, "duplicate key %s in map literal", x.val)
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continue
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}
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}
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check.exprWithHint(x, kv.Value, utyp.elem)
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check.assignment(x, utyp.elem, "map literal")
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}
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default:
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// when "using" all elements unpack KeyValueExpr
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// explicitly because check.use doesn't accept them
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for _, e := range e.ElemList {
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if kv, _ := e.(*syntax.KeyValueExpr); kv != nil {
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// Ideally, we should also "use" kv.Key but we can't know
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// if it's an externally defined struct key or not. Going
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// forward anyway can lead to other errors. Give up instead.
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e = kv.Value
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}
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check.use(e)
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}
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// if utyp is invalid, an error was reported before
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if isValid(utyp) {
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var qualifier string
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if isElem {
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qualifier = " element"
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}
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var cause string
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if utyp == nil {
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cause = " (no core type)"
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}
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check.errorf(e, InvalidLit, "invalid composite literal%s type %s%s", qualifier, typ, cause)
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goto Error
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}
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}
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x.mode = value
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x.typ = typ
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case *syntax.ParenExpr:
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// type inference doesn't go past parentheses (target type T = nil)
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kind := check.rawExpr(nil, x, e.X, nil, false)
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249
src/cmd/compile/internal/types2/literals.go
Normal file
249
src/cmd/compile/internal/types2/literals.go
Normal file
@ -0,0 +1,249 @@
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// Copyright 2024 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// This file implements typechecking of composite literals.
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package types2
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import (
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"cmd/compile/internal/syntax"
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. "internal/types/errors"
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)
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func (check *Checker) compositeLit(T *target, x *operand, e *syntax.CompositeLit, hint Type) {
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var typ, base Type
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var isElem bool // true if composite literal is an element of an enclosing composite literal
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switch {
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case e.Type != nil:
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// composite literal type present - use it
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// [...]T array types may only appear with composite literals.
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// Check for them here so we don't have to handle ... in general.
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if atyp, _ := e.Type.(*syntax.ArrayType); atyp != nil && atyp.Len == nil {
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// We have an "open" [...]T array type.
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// Create a new ArrayType with unknown length (-1)
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// and finish setting it up after analyzing the literal.
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typ = &Array{len: -1, elem: check.varType(atyp.Elem)}
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base = typ
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break
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}
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typ = check.typ(e.Type)
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base = typ
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case hint != nil:
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// no composite literal type present - use hint (element type of enclosing type)
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typ = hint
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base = typ
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// *T implies &T{}
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if b, ok := deref(coreType(base)); ok {
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base = b
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}
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isElem = true
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default:
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// TODO(gri) provide better error messages depending on context
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check.error(e, UntypedLit, "missing type in composite literal")
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x.mode = invalid
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return
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}
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switch utyp := coreType(base).(type) {
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case *Struct:
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// Prevent crash if the struct referred to is not yet set up.
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// See analogous comment for *Array.
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if utyp.fields == nil {
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check.error(e, InvalidTypeCycle, "invalid recursive type")
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x.mode = invalid
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return
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}
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if len(e.ElemList) == 0 {
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break
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}
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// Convention for error messages on invalid struct literals:
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// we mention the struct type only if it clarifies the error
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// (e.g., a duplicate field error doesn't need the struct type).
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fields := utyp.fields
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if _, ok := e.ElemList[0].(*syntax.KeyValueExpr); ok {
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// all elements must have keys
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visited := make([]bool, len(fields))
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for _, e := range e.ElemList {
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kv, _ := e.(*syntax.KeyValueExpr)
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if kv == nil {
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check.error(e, MixedStructLit, "mixture of field:value and value elements in struct literal")
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continue
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}
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key, _ := kv.Key.(*syntax.Name)
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// do all possible checks early (before exiting due to errors)
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// so we don't drop information on the floor
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check.expr(nil, x, kv.Value)
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if key == nil {
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check.errorf(kv, InvalidLitField, "invalid field name %s in struct literal", kv.Key)
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continue
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}
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i := fieldIndex(fields, check.pkg, key.Value, false)
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if i < 0 {
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var alt Object
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if j := fieldIndex(fields, check.pkg, key.Value, true); j >= 0 {
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alt = fields[j]
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}
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msg := check.lookupError(base, key.Value, alt, true)
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check.error(kv.Key, MissingLitField, msg)
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continue
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}
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fld := fields[i]
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check.recordUse(key, fld)
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etyp := fld.typ
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check.assignment(x, etyp, "struct literal")
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// 0 <= i < len(fields)
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if visited[i] {
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check.errorf(kv, DuplicateLitField, "duplicate field name %s in struct literal", key.Value)
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continue
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}
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visited[i] = true
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}
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} else {
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// no element must have a key
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for i, e := range e.ElemList {
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if kv, _ := e.(*syntax.KeyValueExpr); kv != nil {
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check.error(kv, MixedStructLit, "mixture of field:value and value elements in struct literal")
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continue
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}
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check.expr(nil, x, e)
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if i >= len(fields) {
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check.errorf(x, InvalidStructLit, "too many values in struct literal of type %s", base)
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break // cannot continue
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}
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// i < len(fields)
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fld := fields[i]
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if !fld.Exported() && fld.pkg != check.pkg {
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check.errorf(x, UnexportedLitField, "implicit assignment to unexported field %s in struct literal of type %s", fld.name, base)
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continue
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}
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etyp := fld.typ
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check.assignment(x, etyp, "struct literal")
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}
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if len(e.ElemList) < len(fields) {
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check.errorf(e.Rbrace, InvalidStructLit, "too few values in struct literal of type %s", base)
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// ok to continue
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}
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}
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|
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case *Array:
|
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// Prevent crash if the array referred to is not yet set up. Was go.dev/issue/18643.
|
||||
// This is a stop-gap solution. Should use Checker.objPath to report entire
|
||||
// path starting with earliest declaration in the source. TODO(gri) fix this.
|
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if utyp.elem == nil {
|
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check.error(e, InvalidTypeCycle, "invalid recursive type")
|
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x.mode = invalid
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return
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}
|
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n := check.indexedElts(e.ElemList, utyp.elem, utyp.len)
|
||||
// If we have an array of unknown length (usually [...]T arrays, but also
|
||||
// arrays [n]T where n is invalid) set the length now that we know it and
|
||||
// record the type for the array (usually done by check.typ which is not
|
||||
// called for [...]T). We handle [...]T arrays and arrays with invalid
|
||||
// length the same here because it makes sense to "guess" the length for
|
||||
// the latter if we have a composite literal; e.g. for [n]int{1, 2, 3}
|
||||
// where n is invalid for some reason, it seems fair to assume it should
|
||||
// be 3 (see also Checked.arrayLength and go.dev/issue/27346).
|
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if utyp.len < 0 {
|
||||
utyp.len = n
|
||||
// e.Type is missing if we have a composite literal element
|
||||
// that is itself a composite literal with omitted type. In
|
||||
// that case there is nothing to record (there is no type in
|
||||
// the source at that point).
|
||||
if e.Type != nil {
|
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check.recordTypeAndValue(e.Type, typexpr, utyp, nil)
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}
|
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}
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|
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case *Slice:
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// Prevent crash if the slice referred to is not yet set up.
|
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// See analogous comment for *Array.
|
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if utyp.elem == nil {
|
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check.error(e, InvalidTypeCycle, "invalid recursive type")
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x.mode = invalid
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return
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}
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check.indexedElts(e.ElemList, utyp.elem, -1)
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|
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case *Map:
|
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// Prevent crash if the map referred to is not yet set up.
|
||||
// See analogous comment for *Array.
|
||||
if utyp.key == nil || utyp.elem == nil {
|
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check.error(e, InvalidTypeCycle, "invalid recursive type")
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x.mode = invalid
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return
|
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}
|
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// If the map key type is an interface (but not a type parameter),
|
||||
// the type of a constant key must be considered when checking for
|
||||
// duplicates.
|
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keyIsInterface := isNonTypeParamInterface(utyp.key)
|
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visited := make(map[any][]Type, len(e.ElemList))
|
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for _, e := range e.ElemList {
|
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kv, _ := e.(*syntax.KeyValueExpr)
|
||||
if kv == nil {
|
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check.error(e, MissingLitKey, "missing key in map literal")
|
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continue
|
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}
|
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check.exprWithHint(x, kv.Key, utyp.key)
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check.assignment(x, utyp.key, "map literal")
|
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if x.mode == invalid {
|
||||
continue
|
||||
}
|
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if x.mode == constant_ {
|
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duplicate := false
|
||||
xkey := keyVal(x.val)
|
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if keyIsInterface {
|
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for _, vtyp := range visited[xkey] {
|
||||
if Identical(vtyp, x.typ) {
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duplicate = true
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break
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}
|
||||
}
|
||||
visited[xkey] = append(visited[xkey], x.typ)
|
||||
} else {
|
||||
_, duplicate = visited[xkey]
|
||||
visited[xkey] = nil
|
||||
}
|
||||
if duplicate {
|
||||
check.errorf(x, DuplicateLitKey, "duplicate key %s in map literal", x.val)
|
||||
continue
|
||||
}
|
||||
}
|
||||
check.exprWithHint(x, kv.Value, utyp.elem)
|
||||
check.assignment(x, utyp.elem, "map literal")
|
||||
}
|
||||
|
||||
default:
|
||||
// when "using" all elements unpack KeyValueExpr
|
||||
// explicitly because check.use doesn't accept them
|
||||
for _, e := range e.ElemList {
|
||||
if kv, _ := e.(*syntax.KeyValueExpr); kv != nil {
|
||||
// Ideally, we should also "use" kv.Key but we can't know
|
||||
// if it's an externally defined struct key or not. Going
|
||||
// forward anyway can lead to other errors. Give up instead.
|
||||
e = kv.Value
|
||||
}
|
||||
check.use(e)
|
||||
}
|
||||
// if utyp is invalid, an error was reported before
|
||||
if isValid(utyp) {
|
||||
var qualifier string
|
||||
if isElem {
|
||||
qualifier = " element"
|
||||
}
|
||||
var cause string
|
||||
if utyp == nil {
|
||||
cause = " (no core type)"
|
||||
}
|
||||
check.errorf(e, InvalidLit, "invalid composite literal%s type %s%s", qualifier, typ, cause)
|
||||
x.mode = invalid
|
||||
return
|
||||
}
|
||||
}
|
||||
|
||||
x.mode = value
|
||||
x.typ = typ
|
||||
}
|
||||
@ -1128,239 +1128,11 @@ func (check *Checker) exprInternal(T *target, x *operand, e ast.Expr, hint Type)
|
||||
}
|
||||
|
||||
case *ast.CompositeLit:
|
||||
var typ, base Type
|
||||
var isElem bool // true if composite literal is an element of an enclosing composite literal
|
||||
|
||||
switch {
|
||||
case e.Type != nil:
|
||||
// composite literal type present - use it
|
||||
// [...]T array types may only appear with composite literals.
|
||||
// Check for them here so we don't have to handle ... in general.
|
||||
if atyp, _ := e.Type.(*ast.ArrayType); atyp != nil && atyp.Len != nil {
|
||||
if ellip, _ := atyp.Len.(*ast.Ellipsis); ellip != nil && ellip.Elt == nil {
|
||||
// We have an "open" [...]T array type.
|
||||
// Create a new ArrayType with unknown length (-1)
|
||||
// and finish setting it up after analyzing the literal.
|
||||
typ = &Array{len: -1, elem: check.varType(atyp.Elt)}
|
||||
base = typ
|
||||
break
|
||||
}
|
||||
}
|
||||
typ = check.typ(e.Type)
|
||||
base = typ
|
||||
|
||||
case hint != nil:
|
||||
// no composite literal type present - use hint (element type of enclosing type)
|
||||
typ = hint
|
||||
base = typ
|
||||
// *T implies &T{}
|
||||
if b, ok := deref(coreType(base)); ok {
|
||||
base = b
|
||||
}
|
||||
isElem = true
|
||||
|
||||
default:
|
||||
// TODO(gri) provide better error messages depending on context
|
||||
check.error(e, UntypedLit, "missing type in composite literal")
|
||||
check.compositeLit(T, x, e, hint)
|
||||
if x.mode == invalid {
|
||||
goto Error
|
||||
}
|
||||
|
||||
switch utyp := coreType(base).(type) {
|
||||
case *Struct:
|
||||
// Prevent crash if the struct referred to is not yet set up.
|
||||
// See analogous comment for *Array.
|
||||
if utyp.fields == nil {
|
||||
check.error(e, InvalidTypeCycle, "invalid recursive type")
|
||||
goto Error
|
||||
}
|
||||
if len(e.Elts) == 0 {
|
||||
break
|
||||
}
|
||||
// Convention for error messages on invalid struct literals:
|
||||
// we mention the struct type only if it clarifies the error
|
||||
// (e.g., a duplicate field error doesn't need the struct type).
|
||||
fields := utyp.fields
|
||||
if _, ok := e.Elts[0].(*ast.KeyValueExpr); ok {
|
||||
// all elements must have keys
|
||||
visited := make([]bool, len(fields))
|
||||
for _, e := range e.Elts {
|
||||
kv, _ := e.(*ast.KeyValueExpr)
|
||||
if kv == nil {
|
||||
check.error(e, MixedStructLit, "mixture of field:value and value elements in struct literal")
|
||||
continue
|
||||
}
|
||||
key, _ := kv.Key.(*ast.Ident)
|
||||
// do all possible checks early (before exiting due to errors)
|
||||
// so we don't drop information on the floor
|
||||
check.expr(nil, x, kv.Value)
|
||||
if key == nil {
|
||||
check.errorf(kv, InvalidLitField, "invalid field name %s in struct literal", kv.Key)
|
||||
continue
|
||||
}
|
||||
i := fieldIndex(utyp.fields, check.pkg, key.Name, false)
|
||||
if i < 0 {
|
||||
var alt Object
|
||||
if j := fieldIndex(fields, check.pkg, key.Name, true); j >= 0 {
|
||||
alt = fields[j]
|
||||
}
|
||||
msg := check.lookupError(base, key.Name, alt, true)
|
||||
check.error(kv.Key, MissingLitField, msg)
|
||||
continue
|
||||
}
|
||||
fld := fields[i]
|
||||
check.recordUse(key, fld)
|
||||
etyp := fld.typ
|
||||
check.assignment(x, etyp, "struct literal")
|
||||
// 0 <= i < len(fields)
|
||||
if visited[i] {
|
||||
check.errorf(kv, DuplicateLitField, "duplicate field name %s in struct literal", key.Name)
|
||||
continue
|
||||
}
|
||||
visited[i] = true
|
||||
}
|
||||
} else {
|
||||
// no element must have a key
|
||||
for i, e := range e.Elts {
|
||||
if kv, _ := e.(*ast.KeyValueExpr); kv != nil {
|
||||
check.error(kv, MixedStructLit, "mixture of field:value and value elements in struct literal")
|
||||
continue
|
||||
}
|
||||
check.expr(nil, x, e)
|
||||
if i >= len(fields) {
|
||||
check.errorf(x, InvalidStructLit, "too many values in struct literal of type %s", base)
|
||||
break // cannot continue
|
||||
}
|
||||
// i < len(fields)
|
||||
fld := fields[i]
|
||||
if !fld.Exported() && fld.pkg != check.pkg {
|
||||
check.errorf(x,
|
||||
UnexportedLitField,
|
||||
"implicit assignment to unexported field %s in struct literal of type %s", fld.name, base)
|
||||
continue
|
||||
}
|
||||
etyp := fld.typ
|
||||
check.assignment(x, etyp, "struct literal")
|
||||
}
|
||||
if len(e.Elts) < len(fields) {
|
||||
check.errorf(inNode(e, e.Rbrace), InvalidStructLit, "too few values in struct literal of type %s", base)
|
||||
// ok to continue
|
||||
}
|
||||
}
|
||||
|
||||
case *Array:
|
||||
// Prevent crash if the array referred to is not yet set up. Was go.dev/issue/18643.
|
||||
// This is a stop-gap solution. Should use Checker.objPath to report entire
|
||||
// path starting with earliest declaration in the source. TODO(gri) fix this.
|
||||
if utyp.elem == nil {
|
||||
check.error(e, InvalidTypeCycle, "invalid recursive type")
|
||||
goto Error
|
||||
}
|
||||
n := check.indexedElts(e.Elts, utyp.elem, utyp.len)
|
||||
// If we have an array of unknown length (usually [...]T arrays, but also
|
||||
// arrays [n]T where n is invalid) set the length now that we know it and
|
||||
// record the type for the array (usually done by check.typ which is not
|
||||
// called for [...]T). We handle [...]T arrays and arrays with invalid
|
||||
// length the same here because it makes sense to "guess" the length for
|
||||
// the latter if we have a composite literal; e.g. for [n]int{1, 2, 3}
|
||||
// where n is invalid for some reason, it seems fair to assume it should
|
||||
// be 3 (see also Checked.arrayLength and go.dev/issue/27346).
|
||||
if utyp.len < 0 {
|
||||
utyp.len = n
|
||||
// e.Type is missing if we have a composite literal element
|
||||
// that is itself a composite literal with omitted type. In
|
||||
// that case there is nothing to record (there is no type in
|
||||
// the source at that point).
|
||||
if e.Type != nil {
|
||||
check.recordTypeAndValue(e.Type, typexpr, utyp, nil)
|
||||
}
|
||||
}
|
||||
|
||||
case *Slice:
|
||||
// Prevent crash if the slice referred to is not yet set up.
|
||||
// See analogous comment for *Array.
|
||||
if utyp.elem == nil {
|
||||
check.error(e, InvalidTypeCycle, "invalid recursive type")
|
||||
goto Error
|
||||
}
|
||||
check.indexedElts(e.Elts, utyp.elem, -1)
|
||||
|
||||
case *Map:
|
||||
// Prevent crash if the map referred to is not yet set up.
|
||||
// See analogous comment for *Array.
|
||||
if utyp.key == nil || utyp.elem == nil {
|
||||
check.error(e, InvalidTypeCycle, "invalid recursive type")
|
||||
goto Error
|
||||
}
|
||||
// If the map key type is an interface (but not a type parameter),
|
||||
// the type of a constant key must be considered when checking for
|
||||
// duplicates.
|
||||
keyIsInterface := isNonTypeParamInterface(utyp.key)
|
||||
visited := make(map[any][]Type, len(e.Elts))
|
||||
for _, e := range e.Elts {
|
||||
kv, _ := e.(*ast.KeyValueExpr)
|
||||
if kv == nil {
|
||||
check.error(e, MissingLitKey, "missing key in map literal")
|
||||
continue
|
||||
}
|
||||
check.exprWithHint(x, kv.Key, utyp.key)
|
||||
check.assignment(x, utyp.key, "map literal")
|
||||
if x.mode == invalid {
|
||||
continue
|
||||
}
|
||||
if x.mode == constant_ {
|
||||
duplicate := false
|
||||
xkey := keyVal(x.val)
|
||||
if keyIsInterface {
|
||||
for _, vtyp := range visited[xkey] {
|
||||
if Identical(vtyp, x.typ) {
|
||||
duplicate = true
|
||||
break
|
||||
}
|
||||
}
|
||||
visited[xkey] = append(visited[xkey], x.typ)
|
||||
} else {
|
||||
_, duplicate = visited[xkey]
|
||||
visited[xkey] = nil
|
||||
}
|
||||
if duplicate {
|
||||
check.errorf(x, DuplicateLitKey, "duplicate key %s in map literal", x.val)
|
||||
continue
|
||||
}
|
||||
}
|
||||
check.exprWithHint(x, kv.Value, utyp.elem)
|
||||
check.assignment(x, utyp.elem, "map literal")
|
||||
}
|
||||
|
||||
default:
|
||||
// when "using" all elements unpack KeyValueExpr
|
||||
// explicitly because check.use doesn't accept them
|
||||
for _, e := range e.Elts {
|
||||
if kv, _ := e.(*ast.KeyValueExpr); kv != nil {
|
||||
// Ideally, we should also "use" kv.Key but we can't know
|
||||
// if it's an externally defined struct key or not. Going
|
||||
// forward anyway can lead to other errors. Give up instead.
|
||||
e = kv.Value
|
||||
}
|
||||
check.use(e)
|
||||
}
|
||||
// if utyp is invalid, an error was reported before
|
||||
if isValid(utyp) {
|
||||
var qualifier string
|
||||
if isElem {
|
||||
qualifier = " element"
|
||||
}
|
||||
var cause string
|
||||
if utyp == nil {
|
||||
cause = " (no core type)"
|
||||
}
|
||||
check.errorf(e, InvalidLit, "invalid composite literal%s type %s%s", qualifier, typ, cause)
|
||||
goto Error
|
||||
}
|
||||
}
|
||||
|
||||
x.mode = value
|
||||
x.typ = typ
|
||||
|
||||
case *ast.ParenExpr:
|
||||
// type inference doesn't go past parentheses (target type T = nil)
|
||||
kind := check.rawExpr(nil, x, e.X, nil, false)
|
||||
|
||||
253
src/go/types/literals.go
Normal file
253
src/go/types/literals.go
Normal file
@ -0,0 +1,253 @@
|
||||
// Copyright 2024 The Go Authors. All rights reserved.
|
||||
// Use of this source code is governed by a BSD-style
|
||||
// license that can be found in the LICENSE file.
|
||||
|
||||
// This file implements typechecking of composite literals.
|
||||
|
||||
package types
|
||||
|
||||
import (
|
||||
"go/ast"
|
||||
. "internal/types/errors"
|
||||
)
|
||||
|
||||
func (check *Checker) compositeLit(T *target, x *operand, e *ast.CompositeLit, hint Type) {
|
||||
var typ, base Type
|
||||
var isElem bool // true if composite literal is an element of an enclosing composite literal
|
||||
|
||||
switch {
|
||||
case e.Type != nil:
|
||||
// composite literal type present - use it
|
||||
// [...]T array types may only appear with composite literals.
|
||||
// Check for them here so we don't have to handle ... in general.
|
||||
if atyp, _ := e.Type.(*ast.ArrayType); atyp != nil && atyp.Len != nil {
|
||||
if ellip, _ := atyp.Len.(*ast.Ellipsis); ellip != nil && ellip.Elt == nil {
|
||||
// We have an "open" [...]T array type.
|
||||
// Create a new ArrayType with unknown length (-1)
|
||||
// and finish setting it up after analyzing the literal.
|
||||
typ = &Array{len: -1, elem: check.varType(atyp.Elt)}
|
||||
base = typ
|
||||
break
|
||||
}
|
||||
}
|
||||
typ = check.typ(e.Type)
|
||||
base = typ
|
||||
|
||||
case hint != nil:
|
||||
// no composite literal type present - use hint (element type of enclosing type)
|
||||
typ = hint
|
||||
base = typ
|
||||
// *T implies &T{}
|
||||
if b, ok := deref(coreType(base)); ok {
|
||||
base = b
|
||||
}
|
||||
isElem = true
|
||||
|
||||
default:
|
||||
// TODO(gri) provide better error messages depending on context
|
||||
check.error(e, UntypedLit, "missing type in composite literal")
|
||||
x.mode = invalid
|
||||
return
|
||||
}
|
||||
|
||||
switch utyp := coreType(base).(type) {
|
||||
case *Struct:
|
||||
// Prevent crash if the struct referred to is not yet set up.
|
||||
// See analogous comment for *Array.
|
||||
if utyp.fields == nil {
|
||||
check.error(e, InvalidTypeCycle, "invalid recursive type")
|
||||
x.mode = invalid
|
||||
return
|
||||
}
|
||||
if len(e.Elts) == 0 {
|
||||
break
|
||||
}
|
||||
// Convention for error messages on invalid struct literals:
|
||||
// we mention the struct type only if it clarifies the error
|
||||
// (e.g., a duplicate field error doesn't need the struct type).
|
||||
fields := utyp.fields
|
||||
if _, ok := e.Elts[0].(*ast.KeyValueExpr); ok {
|
||||
// all elements must have keys
|
||||
visited := make([]bool, len(fields))
|
||||
for _, e := range e.Elts {
|
||||
kv, _ := e.(*ast.KeyValueExpr)
|
||||
if kv == nil {
|
||||
check.error(e, MixedStructLit, "mixture of field:value and value elements in struct literal")
|
||||
continue
|
||||
}
|
||||
key, _ := kv.Key.(*ast.Ident)
|
||||
// do all possible checks early (before exiting due to errors)
|
||||
// so we don't drop information on the floor
|
||||
check.expr(nil, x, kv.Value)
|
||||
if key == nil {
|
||||
check.errorf(kv, InvalidLitField, "invalid field name %s in struct literal", kv.Key)
|
||||
continue
|
||||
}
|
||||
i := fieldIndex(utyp.fields, check.pkg, key.Name, false)
|
||||
if i < 0 {
|
||||
var alt Object
|
||||
if j := fieldIndex(fields, check.pkg, key.Name, true); j >= 0 {
|
||||
alt = fields[j]
|
||||
}
|
||||
msg := check.lookupError(base, key.Name, alt, true)
|
||||
check.error(kv.Key, MissingLitField, msg)
|
||||
continue
|
||||
}
|
||||
fld := fields[i]
|
||||
check.recordUse(key, fld)
|
||||
etyp := fld.typ
|
||||
check.assignment(x, etyp, "struct literal")
|
||||
// 0 <= i < len(fields)
|
||||
if visited[i] {
|
||||
check.errorf(kv, DuplicateLitField, "duplicate field name %s in struct literal", key.Name)
|
||||
continue
|
||||
}
|
||||
visited[i] = true
|
||||
}
|
||||
} else {
|
||||
// no element must have a key
|
||||
for i, e := range e.Elts {
|
||||
if kv, _ := e.(*ast.KeyValueExpr); kv != nil {
|
||||
check.error(kv, MixedStructLit, "mixture of field:value and value elements in struct literal")
|
||||
continue
|
||||
}
|
||||
check.expr(nil, x, e)
|
||||
if i >= len(fields) {
|
||||
check.errorf(x, InvalidStructLit, "too many values in struct literal of type %s", base)
|
||||
break // cannot continue
|
||||
}
|
||||
// i < len(fields)
|
||||
fld := fields[i]
|
||||
if !fld.Exported() && fld.pkg != check.pkg {
|
||||
check.errorf(x,
|
||||
UnexportedLitField,
|
||||
"implicit assignment to unexported field %s in struct literal of type %s", fld.name, base)
|
||||
continue
|
||||
}
|
||||
etyp := fld.typ
|
||||
check.assignment(x, etyp, "struct literal")
|
||||
}
|
||||
if len(e.Elts) < len(fields) {
|
||||
check.errorf(inNode(e, e.Rbrace), InvalidStructLit, "too few values in struct literal of type %s", base)
|
||||
// ok to continue
|
||||
}
|
||||
}
|
||||
|
||||
case *Array:
|
||||
// Prevent crash if the array referred to is not yet set up. Was go.dev/issue/18643.
|
||||
// This is a stop-gap solution. Should use Checker.objPath to report entire
|
||||
// path starting with earliest declaration in the source. TODO(gri) fix this.
|
||||
if utyp.elem == nil {
|
||||
check.error(e, InvalidTypeCycle, "invalid recursive type")
|
||||
x.mode = invalid
|
||||
return
|
||||
}
|
||||
n := check.indexedElts(e.Elts, utyp.elem, utyp.len)
|
||||
// If we have an array of unknown length (usually [...]T arrays, but also
|
||||
// arrays [n]T where n is invalid) set the length now that we know it and
|
||||
// record the type for the array (usually done by check.typ which is not
|
||||
// called for [...]T). We handle [...]T arrays and arrays with invalid
|
||||
// length the same here because it makes sense to "guess" the length for
|
||||
// the latter if we have a composite literal; e.g. for [n]int{1, 2, 3}
|
||||
// where n is invalid for some reason, it seems fair to assume it should
|
||||
// be 3 (see also Checked.arrayLength and go.dev/issue/27346).
|
||||
if utyp.len < 0 {
|
||||
utyp.len = n
|
||||
// e.Type is missing if we have a composite literal element
|
||||
// that is itself a composite literal with omitted type. In
|
||||
// that case there is nothing to record (there is no type in
|
||||
// the source at that point).
|
||||
if e.Type != nil {
|
||||
check.recordTypeAndValue(e.Type, typexpr, utyp, nil)
|
||||
}
|
||||
}
|
||||
|
||||
case *Slice:
|
||||
// Prevent crash if the slice referred to is not yet set up.
|
||||
// See analogous comment for *Array.
|
||||
if utyp.elem == nil {
|
||||
check.error(e, InvalidTypeCycle, "invalid recursive type")
|
||||
x.mode = invalid
|
||||
return
|
||||
}
|
||||
check.indexedElts(e.Elts, utyp.elem, -1)
|
||||
|
||||
case *Map:
|
||||
// Prevent crash if the map referred to is not yet set up.
|
||||
// See analogous comment for *Array.
|
||||
if utyp.key == nil || utyp.elem == nil {
|
||||
check.error(e, InvalidTypeCycle, "invalid recursive type")
|
||||
x.mode = invalid
|
||||
return
|
||||
}
|
||||
// If the map key type is an interface (but not a type parameter),
|
||||
// the type of a constant key must be considered when checking for
|
||||
// duplicates.
|
||||
keyIsInterface := isNonTypeParamInterface(utyp.key)
|
||||
visited := make(map[any][]Type, len(e.Elts))
|
||||
for _, e := range e.Elts {
|
||||
kv, _ := e.(*ast.KeyValueExpr)
|
||||
if kv == nil {
|
||||
check.error(e, MissingLitKey, "missing key in map literal")
|
||||
continue
|
||||
}
|
||||
check.exprWithHint(x, kv.Key, utyp.key)
|
||||
check.assignment(x, utyp.key, "map literal")
|
||||
if x.mode == invalid {
|
||||
continue
|
||||
}
|
||||
if x.mode == constant_ {
|
||||
duplicate := false
|
||||
xkey := keyVal(x.val)
|
||||
if keyIsInterface {
|
||||
for _, vtyp := range visited[xkey] {
|
||||
if Identical(vtyp, x.typ) {
|
||||
duplicate = true
|
||||
break
|
||||
}
|
||||
}
|
||||
visited[xkey] = append(visited[xkey], x.typ)
|
||||
} else {
|
||||
_, duplicate = visited[xkey]
|
||||
visited[xkey] = nil
|
||||
}
|
||||
if duplicate {
|
||||
check.errorf(x, DuplicateLitKey, "duplicate key %s in map literal", x.val)
|
||||
continue
|
||||
}
|
||||
}
|
||||
check.exprWithHint(x, kv.Value, utyp.elem)
|
||||
check.assignment(x, utyp.elem, "map literal")
|
||||
}
|
||||
|
||||
default:
|
||||
// when "using" all elements unpack KeyValueExpr
|
||||
// explicitly because check.use doesn't accept them
|
||||
for _, e := range e.Elts {
|
||||
if kv, _ := e.(*ast.KeyValueExpr); kv != nil {
|
||||
// Ideally, we should also "use" kv.Key but we can't know
|
||||
// if it's an externally defined struct key or not. Going
|
||||
// forward anyway can lead to other errors. Give up instead.
|
||||
e = kv.Value
|
||||
}
|
||||
check.use(e)
|
||||
}
|
||||
// if utyp is invalid, an error was reported before
|
||||
if isValid(utyp) {
|
||||
var qualifier string
|
||||
if isElem {
|
||||
qualifier = " element"
|
||||
}
|
||||
var cause string
|
||||
if utyp == nil {
|
||||
cause = " (no core type)"
|
||||
}
|
||||
check.errorf(e, InvalidLit, "invalid composite literal%s type %s%s", qualifier, typ, cause)
|
||||
x.mode = invalid
|
||||
return
|
||||
}
|
||||
}
|
||||
|
||||
x.mode = value
|
||||
x.typ = typ
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user