Improve expression parsing

Allow ':super' to be used as a member.
Search super types when locating field members.
Fixes #16

src/debugMain.js

@@ -849,7 +849,7 @@ class AndroidDebugSession extends DebugSession {
                     // ignore supertypes of Object
                     x.supertype && x.supertype.signature!=='Ljava/lang/Object;' && fields.unshift({
                         vtype:'super',
-                        name:'super',
+                        name:':super',
                         hasnullvalue:false,
                         type: x.supertype,
                         value: x.varinfo.objvar.value,
@@ -1273,10 +1273,12 @@ class AndroidDebugSession extends DebugSession {
         const resolve_evaluation = (value, variablesReference) => $.Deferred().resolveWith(this, [value, variablesReference]);
 
         // special case for evaluating exception messages
-        // - this is called if the user uses "Copy value" from the locals
+        // - this is called if the user tries to evaluate ':msg' from the locals
         if (expression===this._exmsg_var_name && this._last_exception && this._last_exception.cached) {
             var msglocal = this._last_exception.cached.find(v => v.name===this._exmsg_var_name);
-            if (msglocal) return resolve_evaluation(msglocal.string);
+            if (msglocal) {
+                return resolve_evaluation(this._local_to_variable(msglocal).value);
+            }
         }
 
         const parse_array_or_fncall = function(e) {
@@ -1330,7 +1332,7 @@ class AndroidDebugSession extends DebugSession {
             while (e.expr[0] === '.') {
                 // member expression
                 e.expr = e.expr.slice(1).trim();
-                var m, member_name = e.expr.match(/^[a-zA-Z_$][a-zA-Z0-9_$]*/);
+                var m, member_name = e.expr.match(/^:?[a-zA-Z_$][a-zA-Z0-9_$]*/);   // allow : at start for :super and :msg
                 if (!member_name) return null;
                 res.members.push(m = {member:member_name[0], array_or_fncall:null})
                 e.expr = e.expr.slice(m.member.length).trim();
@@ -1403,23 +1405,32 @@ class AndroidDebugSession extends DebugSession {
         const evaluate_member = (m, obj_local) => {
             if (!JTYPES.isReference(obj_local.type)) return reject_evaluation('TypeError: value is not a reference type');
             if (obj_local.hasnullvalue) return reject_evaluation('NullPointerException');
-            if (m.array_or_fncall.call) return evaluate_methodcall(m, obj_local);
+            var chain;
+            if (m.array_or_fncall.call){
+                chain = evaluate_methodcall(m, obj_local);
+            } 
             // length is a 'fake' field of arrays, so special-case it
-            if (JTYPES.isArray(obj_local.type) && m.member==='length') 
+            else if (JTYPES.isArray(obj_local.type) && m.member==='length') {
-                return evaluate_number(obj_local.arraylen);
+                chain = evaluate_number(obj_local.arraylen);
-            return this.dbgr.getfieldvalues(obj_local, m)
+            }
-                .then((fields,m) => {
+            // we also special-case :super (for object instances)
-                    var field = fields.find(f => f.name === m.member);
+            else if (JTYPES.isObject(obj_local.type) && m.member === ':super') {
-                    if (!field) return reject_evaluation('no such field: '+m.member);
+                chain = this.dbgr.getsuperinstance(obj_local);
+            } 
+            // anything else must be a real field
+            else {
+                chain = this.dbgr.getFieldValue(obj_local, m.member, true)
+            }
+
+            return chain.then(local => {
                 if (m.array_or_fncall.arr.length) {
                     var q = $.Deferred();
                     m.array_or_fncall.arr.reduce((q,index_expr) => {
                         return q.then(function(index_expr,local) { return evaluate_array_element(index_expr,local) }.bind(this,index_expr));
                     }, q);
-                        return q.resolveWith(this, [field]);
+                    return q.resolveWith(this, [local]);
                 }
-                    return field;
+            });
-                })
         }
 
         var e = { expr:expression.trim() };

src/debugger.js

@@ -721,6 +721,15 @@ Debugger.prototype = {
             });
     },
 
+    getsuperinstance: function (local, extra) {
+        return this.getsupertype(local, {local,extra})
+            .then(function (supertypeinfo, x) {
+                var castobj = Object.assign({}, x.local);
+                castobj.type = supertypeinfo;
+                return $.Deferred().resolveWith(this, [castobj, x.extra]);
+            });
+    },
+
     createstring: function (string, extra) {
         return this.ensureconnected({ string: string, extra: extra })
             .then(function (x) {
@@ -838,6 +847,25 @@ Debugger.prototype = {
             });
     },
 
+    getFieldValue: function(objvar, fieldname, includeInherited, extra) {
+        const findfield = x => {
+            return this.getfieldvalues(x.objvar, x)
+                .then((fields, x) => {
+                    var field = fields.find(f => f.name === x.fieldname);
+                    if (field) return $.Deferred().resolveWith(this,[field,x.extra]);
+                    if (!x.includeInherited || x.objvar.type.signature==='Ljava/lang/Object;')
+                        return $.Deferred().rejectWith(this,[new Error('No such field: '+x.fieldname), x.extra]);
+                    // search supertype
+                    return this.getsuperinstance(x.objvar, x)
+                        .then((superobjvar,x) => {
+                            x.objvar = superobjvar;
+                            return x.findfield(x);
+                        });
+                });
+        }
+        return findfield({findfield, objvar, fieldname, includeInherited, extra});
+    },
+
     getExceptionLocal: function (ex_ref_value, extra) {
         var x = {
             ex_ref_value: ex_ref_value,