diff options
Diffstat (limited to 'src/reflect/type.go')
| -rw-r--r-- | src/reflect/type.go | 82 |
1 files changed, 34 insertions, 48 deletions
diff --git a/src/reflect/type.go b/src/reflect/type.go index d323828c74..dc235ea8f7 100644 --- a/src/reflect/type.go +++ b/src/reflect/type.go @@ -568,12 +568,13 @@ func newName(n, tag string, exported bool) name { // Method represents a single method. type Method struct { // Name is the method name. + Name string + // PkgPath is the package path that qualifies a lower case (unexported) // method name. It is empty for upper case (exported) method names. // The combination of PkgPath and Name uniquely identifies a method // in a method set. // See https://golang.org/ref/spec#Uniqueness_of_identifiers - Name string PkgPath string Type Type // method type @@ -581,6 +582,11 @@ type Method struct { Index int // index for Type.Method } +// IsExported reports whether the method is exported. +func (m Method) IsExported() bool { + return m.PkgPath == "" +} + const ( kindDirectIface = 1 << 5 kindGCProg = 1 << 6 // Type.gc points to GC program @@ -1090,6 +1096,7 @@ func (t *interfaceType) MethodByName(name string) (m Method, ok bool) { type StructField struct { // Name is the field name. Name string + // PkgPath is the package path that qualifies a lower case (unexported) // field name. It is empty for upper case (exported) field names. // See https://golang.org/ref/spec#Uniqueness_of_identifiers @@ -1102,6 +1109,11 @@ type StructField struct { Anonymous bool // is an embedded field } +// IsExported reports whether the field is exported. +func (f StructField) IsExported() bool { + return f.PkgPath == "" +} + // A StructTag is the tag string in a struct field. // // By convention, tag strings are a concatenation of @@ -1723,7 +1735,7 @@ func typesByString(s string) []*rtype { // This is a copy of sort.Search, with f(h) replaced by (*typ[h].String() >= s). i, j := 0, len(offs) for i < j { - h := i + (j-i)/2 // avoid overflow when computing h + h := i + (j-i)>>1 // avoid overflow when computing h // i ≤ h < j if !(rtypeOff(section, offs[h]).String() >= s) { i = h + 1 // preserves f(i-1) == false @@ -2771,8 +2783,7 @@ func runtimeStructField(field StructField) (structField, string) { panic("reflect.StructOf: field \"" + field.Name + "\" is anonymous but has PkgPath set") } - exported := field.PkgPath == "" - if exported { + if field.IsExported() { // Best-effort check for misuse. // Since this field will be treated as exported, not much harm done if Unicode lowercase slips through. c := field.Name[0] @@ -2788,7 +2799,7 @@ func runtimeStructField(field StructField) (structField, string) { resolveReflectType(field.Type.common()) // install in runtime f := structField{ - name: newName(field.Name, string(field.Tag), exported), + name: newName(field.Name, string(field.Tag), field.IsExported()), typ: field.Type.common(), offsetEmbed: offsetEmbed, } @@ -2984,21 +2995,20 @@ type layoutKey struct { type layoutType struct { t *rtype - argSize uintptr // size of arguments - retOffset uintptr // offset of return values. - stack *bitVector framePool *sync.Pool + abi abiDesc } var layoutCache sync.Map // map[layoutKey]layoutType // funcLayout computes a struct type representing the layout of the -// function arguments and return values for the function type t. +// stack-assigned function arguments and return values for the function +// type t. // If rcvr != nil, rcvr specifies the type of the receiver. // The returned type exists only for GC, so we only fill out GC relevant info. // Currently, that's just size and the GC program. We also fill in // the name for possible debugging use. -func funcLayout(t *funcType, rcvr *rtype) (frametype *rtype, argSize, retOffset uintptr, stk *bitVector, framePool *sync.Pool) { +func funcLayout(t *funcType, rcvr *rtype) (frametype *rtype, framePool *sync.Pool, abi abiDesc) { if t.Kind() != Func { panic("reflect: funcLayout of non-func type " + t.String()) } @@ -3008,46 +3018,24 @@ func funcLayout(t *funcType, rcvr *rtype) (frametype *rtype, argSize, retOffset k := layoutKey{t, rcvr} if lti, ok := layoutCache.Load(k); ok { lt := lti.(layoutType) - return lt.t, lt.argSize, lt.retOffset, lt.stack, lt.framePool + return lt.t, lt.framePool, lt.abi } - // compute gc program & stack bitmap for arguments - ptrmap := new(bitVector) - var offset uintptr - if rcvr != nil { - // Reflect uses the "interface" calling convention for - // methods, where receivers take one word of argument - // space no matter how big they actually are. - if ifaceIndir(rcvr) || rcvr.pointers() { - ptrmap.append(1) - } else { - ptrmap.append(0) - } - offset += ptrSize - } - for _, arg := range t.in() { - offset += -offset & uintptr(arg.align-1) - addTypeBits(ptrmap, offset, arg) - offset += arg.size - } - argSize = offset - offset += -offset & (ptrSize - 1) - retOffset = offset - for _, res := range t.out() { - offset += -offset & uintptr(res.align-1) - addTypeBits(ptrmap, offset, res) - offset += res.size - } - offset += -offset & (ptrSize - 1) + // Compute the ABI layout. + abi = newAbiDesc(t, rcvr) // build dummy rtype holding gc program x := &rtype{ - align: ptrSize, - size: offset, - ptrdata: uintptr(ptrmap.n) * ptrSize, + align: ptrSize, + // Don't add spill space here; it's only necessary in + // reflectcall's frame, not in the allocated frame. + // TODO(mknyszek): Remove this comment when register + // spill space in the frame is no longer required. + size: align(abi.retOffset+abi.ret.stackBytes, ptrSize), + ptrdata: uintptr(abi.stackPtrs.n) * ptrSize, } - if ptrmap.n > 0 { - x.gcdata = &ptrmap.data[0] + if abi.stackPtrs.n > 0 { + x.gcdata = &abi.stackPtrs.data[0] } var s string @@ -3064,13 +3052,11 @@ func funcLayout(t *funcType, rcvr *rtype) (frametype *rtype, argSize, retOffset }} lti, _ := layoutCache.LoadOrStore(k, layoutType{ t: x, - argSize: argSize, - retOffset: retOffset, - stack: ptrmap, framePool: framePool, + abi: abi, }) lt := lti.(layoutType) - return lt.t, lt.argSize, lt.retOffset, lt.stack, lt.framePool + return lt.t, lt.framePool, lt.abi } // ifaceIndir reports whether t is stored indirectly in an interface value. |