codecgen: use fully qualified name even for embedded fields

This allows us support embedded types with similarly named fields.

For example, if a struct T has a field named T, and the type T is
embedded within another type, then previously we used the shorthand
of the fieldname (i.e. instead of x.T.T, we used x.T) which was
resolved to the embedded type not its embedded field.

Now, we always use the fully qualified name.

Fixes #297

codec/gen.go

@@ -658,7 +658,7 @@ func (x *genRunner) registerXtraT(t reflect.Type) {
 // encVar will encode a variable.
 // The parameter, t, is the reflect.Type of the variable itself
 func (x *genRunner) encVar(varname string, t reflect.Type) {
-	// fmt.Printf(">>>>>> varname: %s, t: %v\n", varname, t)
+	// xdebugf("varname: %s, t: %v", varname, t)
 	var checkNil bool
 	switch t.Kind() {
 	case reflect.Ptr, reflect.Interface, reflect.Slice, reflect.Map, reflect.Chan:
@@ -935,6 +935,7 @@ func (x *genRunner) encOmitEmptyLine(t2 reflect.StructField, varname string, buf
 }
 
 func (x *genRunner) encStruct(varname string, rtid uintptr, t reflect.Type) {
+	// xdebug2f("encStruct, varname: %s, t: %s", varname, t)
 	// Use knowledge from structfieldinfo (mbs, encodable fields. Ignore omitempty. )
 	// replicate code in kStruct i.e. for each field, deref type to non-pointer, and call x.enc on it
 
@@ -1020,9 +1021,9 @@ func (x *genRunner) encStruct(varname string, rtid uintptr, t reflect.Type) {
 		isNilVarName := genTempVarPfx + "n" + i
 		var labelUsed bool
 		var t2 reflect.StructField
+		varname3 := varname
 		{
 			t2typ := t
-			varname3 := varname
 			for ij, ix := range si.is {
 				if uint8(ij) == si.nis {
 					break
@@ -1059,7 +1060,8 @@ func (x *genRunner) encStruct(varname string, rtid uintptr, t reflect.Type) {
 		if si.omitEmpty() {
 			x.linef("if %s[%v] {", numfieldsvar, j)
 		}
-		x.encVar(varname+"."+t2.Name, t2.Type)
+		// xdebug2f("varname: %s, t2.Type: %s", varname3, t2.Type)
+		x.encVar(varname3, t2.Type)
 		if si.omitEmpty() {
 			x.linef("} else {")
 			x.encZero(t2.Type)
@@ -1097,10 +1099,10 @@ func (x *genRunner) encStruct(varname string, rtid uintptr, t reflect.Type) {
 		x.line("r.WriteMapElemValue()")
 		if labelUsed {
 			x.line("if " + isNilVarName + " { r.EncodeNil() } else { ")
-			x.encVar(varname+"."+t2.Name, t2.Type)
+			x.encVar(varname3, t2.Type)
 			x.line("}")
 		} else {
-			x.encVar(varname+"."+t2.Name, t2.Type)
+			x.encVar(varname3, t2.Type)
 		}
 		if si.omitEmpty() {
 			x.line("}")
@@ -1175,11 +1177,11 @@ func (x *genRunner) encMapFallback(varname string, t reflect.Type) {
 }
 
 func (x *genRunner) decVarInitPtr(varname, nilvar string, t reflect.Type, si *structFieldInfo,
-	newbuf, nilbuf *genBuf) (t2 reflect.StructField) {
+	newbuf, nilbuf *genBuf) (varname3 string, t2 reflect.StructField) {
 	//we must accommodate anonymous fields, where the embedded field is a nil pointer in the value.
 	// t2 = t.FieldByIndex(si.is)
+	varname3 = varname
 	t2typ := t
-	varname3 := varname
 	t2kind := t2typ.Kind()
 	var nilbufed bool
 	if si != nil {
@@ -1231,7 +1233,7 @@ func (x *genRunner) decVarInitPtr(varname, nilvar string, t reflect.Type, si *st
 			nilbuf.s("}")
 		}
 	}
-	return t2
+	return
 }
 
 // decVar takes a variable called varname, of type t
@@ -1607,9 +1609,9 @@ func (x *genRunner) decStructMapSwitch(kName string, varname string, rtid uintpt
 		x.line("case \"" + si.encName + "\":")
 		newbuf.reset()
 		nilbuf.reset()
-		t2 := x.decVarInitPtr(varname, "", t, si, &newbuf, &nilbuf)
+		varname3, t2 := x.decVarInitPtr(varname, "", t, si, &newbuf, &nilbuf)
 		x.linef("if r.TryDecodeAsNil() { %s } else { %s", nilbuf.buf, newbuf.buf)
-		x.decVarMain(varname+"."+t2.Name, x.varsfx(), t2.Type, false)
+		x.decVarMain(varname3, x.varsfx(), t2.Type, false)
 		x.line("}")
 	}
 	x.line("default:")
@@ -1674,9 +1676,9 @@ func (x *genRunner) decStructArray(varname, lenvarname, breakString string, rtid
 		x.line("r.ReadArrayElem()")
 		newbuf.reset()
 		nilbuf.reset()
-		t2 := x.decVarInitPtr(varname, "", t, si, &newbuf, &nilbuf)
+		varname3, t2 := x.decVarInitPtr(varname, "", t, si, &newbuf, &nilbuf)
 		x.linef("if r.TryDecodeAsNil() { %s } else { %s", nilbuf.buf, newbuf.buf)
-		x.decVarMain(varname+"."+t2.Name, x.varsfx(), t2.Type, false)
+		x.decVarMain(varname3, x.varsfx(), t2.Type, false)
 		x.line("}")
 	}
 	// read remaining values and throw away.