Add comment for getinvokememberexpressionast method in Helper

Quoc Truong · Quoc Truong · commit 1772ad903355 · 2015-04-06T13:49:09.000-07:00
diff --git a/Engine/Helper.cs b/Engine/Helper.cs
@@ -470,7 +470,7 @@ public string GetTypeFromReturnStatementAst(Ast funcAst, ReturnStatementAst ret,
                         }
                         else if (cmAst.Expression is MemberExpressionAst)
                         {
-                            result = GetTypeFromMemberExpressionAstHelper(cmAst.Expression as MemberExpressionAst, funcAst, classes);
+                            result = GetTypeFromMemberExpressionAst(cmAst.Expression as MemberExpressionAst, funcAst, classes);
                         }
                     }
                 }
@@ -484,7 +484,16 @@ public string GetTypeFromReturnStatementAst(Ast funcAst, ReturnStatementAst ret,
             return result;
         }
 
-        internal string GetTypeFromMemberExpressionAstHelper(MemberExpressionAst memberAst, Ast scopeAst, IEnumerable<TypeDefinitionAst> classes)
+        /// <summary>
+        /// Returns the type from member expression ast, which is inside scopeAst.
+        /// This function assumes that Initialize Variable Analysis is already run on scopeAst.
+        /// Classes represent the list of DSC classes in the script.
+        /// </summary>
+        /// <param name="memberAst"></param>
+        /// <param name="scopeAst"></param>
+        /// <param name="classes"></param>
+        /// <returns></returns>
+        public string GetTypeFromMemberExpressionAst(MemberExpressionAst memberAst, Ast scopeAst, IEnumerable<TypeDefinitionAst> classes)
         {
             if (memberAst == null)
             {
@@ -497,28 +506,33 @@ internal string GetTypeFromMemberExpressionAstHelper(MemberExpressionAst memberA
             if (memberAst.Expression is VariableExpressionAst && VariableAnalysisDictionary.ContainsKey(scopeAst))
             {
                 VariableAnalysis VarTypeAnalysis = VariableAnalysisDictionary[scopeAst];
+                // Get the analysis detail for the variable
                 details = VarTypeAnalysis.GetVariableAnalysis(memberAst.Expression as VariableExpressionAst);
 
                 if (details != null && classes != null)
                 {
+                    // Get the class that corresponds to the name of the type (if possible)
                     psClass = classes.FirstOrDefault(item => String.Equals(item.Name, details.Type.FullName, StringComparison.OrdinalIgnoreCase));
                 }
             }
 
-            return GetTypeFromMemberExpressionAst(memberAst, psClass, details);
+            return GetTypeFromMemberExpressionAstHelper(memberAst, psClass, details);
         }
 
         /// <summary>
-        /// Retrieves the type from member expression ast
+        /// Retrieves the type from member expression ast. psClass is the powershell class
+        /// that represents the type of the object being invoked on (psClass may be null too).
         /// </summary>
         /// <param name="memberAst"></param>
         /// <param name="psClass"></param>
         /// <param name="analysisDetails"></param>
         /// <returns></returns>
-        public string GetTypeFromMemberExpressionAst(MemberExpressionAst memberAst, TypeDefinitionAst psClass, VariableAnalysisDetails analysisDetails)
+        internal string GetTypeFromMemberExpressionAstHelper(MemberExpressionAst memberAst, TypeDefinitionAst psClass, VariableAnalysisDetails analysisDetails)
         {
+            //Try to get the type without using psClass first
             Type result = AssignmentTarget.GetTypeFromMemberExpressionAst(memberAst);
 
+            //If we can't get the type, then it may be that the type of the object being invoked on is a powershell class
             if (result == null && psClass != null && analysisDetails != null)
             {
                 result = AssignmentTarget.GetTypeFromMemberExpressionAst(memberAst, analysisDetails, psClass);
@@ -1131,7 +1145,7 @@ public object VisitReturnStatement(ReturnStatementAst returnStatementAst)
         /// <returns></returns>
         public object VisitMemberExpression(MemberExpressionAst memAst)
         {
-            return Helper.Instance.GetTypeFromMemberExpressionAstHelper(memAst, myFunction, classes);
+            return Helper.Instance.GetTypeFromMemberExpressionAst(memAst, myFunction, classes);
         }
 
         /// <summary>
@@ -1141,7 +1155,7 @@ public object VisitMemberExpression(MemberExpressionAst memAst)
         /// <returns></returns>
         public object VisitInvokeMemberExpression(InvokeMemberExpressionAst invokeAst)
         {
-            return Helper.Instance.GetTypeFromMemberExpressionAstHelper(invokeAst, myFunction, classes);
+            return Helper.Instance.GetTypeFromMemberExpressionAst(invokeAst, myFunction, classes);
         }
 
         /// <summary>
diff --git a/Engine/VariableAnalysisBase.cs b/Engine/VariableAnalysisBase.cs
@@ -1205,7 +1205,7 @@ public AssignmentTarget(AssignmentStatementAst ast)
                     _rightHandSideVariable = new VariableTarget(cmExAst.Expression as VariableExpressionAst);
                     if (String.Equals((exprAst as VariableExpressionAst).VariablePath.UserPath, "this", StringComparison.OrdinalIgnoreCase))
                     {
-
+                        Constant = SpecialVars.ThisVariable;
                     }
                 }
                 //Store the type info for variable assignment from .Net type

Original file line number	Diff line number	Diff line change
`@@ -470,7 +470,7 @@ public string GetTypeFromReturnStatementAst(Ast funcAst, ReturnStatementAst ret,`
`470`	`470`	`}`
`471`	`471`	`else if (cmAst.Expression is MemberExpressionAst)`
`472`	`472`	`{`
`473`		`- result = GetTypeFromMemberExpressionAstHelper(cmAst.Expression as MemberExpressionAst, funcAst, classes);`
	`473`	`+ result = GetTypeFromMemberExpressionAst(cmAst.Expression as MemberExpressionAst, funcAst, classes);`
`474`	`474`	`}`
`475`	`475`	`}`
`476`	`476`	`}`
`@@ -484,7 +484,16 @@ public string GetTypeFromReturnStatementAst(Ast funcAst, ReturnStatementAst ret,`
`484`	`484`	`return result;`
`485`	`485`	`}`
`486`	`486`
`487`		`- internal string GetTypeFromMemberExpressionAstHelper(MemberExpressionAst memberAst, Ast scopeAst, IEnumerable<TypeDefinitionAst> classes)`
	`487`	`+ /// <summary>`
	`488`	`+ /// Returns the type from member expression ast, which is inside scopeAst.`
	`489`	`+ /// This function assumes that Initialize Variable Analysis is already run on scopeAst.`
	`490`	`+ /// Classes represent the list of DSC classes in the script.`
	`491`	`+ /// </summary>`
	`492`	`+ /// <param name="memberAst"></param>`
	`493`	`+ /// <param name="scopeAst"></param>`
	`494`	`+ /// <param name="classes"></param>`
	`495`	`+ /// <returns></returns>`
	`496`	`+ public string GetTypeFromMemberExpressionAst(MemberExpressionAst memberAst, Ast scopeAst, IEnumerable<TypeDefinitionAst> classes)`
`488`	`497`	`{`
`489`	`498`	`if (memberAst == null)`
`490`	`499`	`{`
`@@ -497,28 +506,33 @@ internal string GetTypeFromMemberExpressionAstHelper(MemberExpressionAst memberA`
`497`	`506`	`if (memberAst.Expression is VariableExpressionAst && VariableAnalysisDictionary.ContainsKey(scopeAst))`
`498`	`507`	`{`
`499`	`508`	`VariableAnalysis VarTypeAnalysis = VariableAnalysisDictionary[scopeAst];`
	`509`	`+ // Get the analysis detail for the variable`
`500`	`510`	`details = VarTypeAnalysis.GetVariableAnalysis(memberAst.Expression as VariableExpressionAst);`
`501`	`511`
`502`	`512`	`if (details != null && classes != null)`
`503`	`513`	`{`
	`514`	`+ // Get the class that corresponds to the name of the type (if possible)`
`504`	`515`	`psClass = classes.FirstOrDefault(item => String.Equals(item.Name, details.Type.FullName, StringComparison.OrdinalIgnoreCase));`
`505`	`516`	`}`
`506`	`517`	`}`
`507`	`518`
`508`		`- return GetTypeFromMemberExpressionAst(memberAst, psClass, details);`
	`519`	`+ return GetTypeFromMemberExpressionAstHelper(memberAst, psClass, details);`
`509`	`520`	`}`
`510`	`521`
`511`	`522`	`/// <summary>`
`512`		`- /// Retrieves the type from member expression ast`
	`523`	`+ /// Retrieves the type from member expression ast. psClass is the powershell class`
	`524`	`+ /// that represents the type of the object being invoked on (psClass may be null too).`
`513`	`525`	`/// </summary>`
`514`	`526`	`/// <param name="memberAst"></param>`
`515`	`527`	`/// <param name="psClass"></param>`
`516`	`528`	`/// <param name="analysisDetails"></param>`
`517`	`529`	`/// <returns></returns>`
`518`		`- public string GetTypeFromMemberExpressionAst(MemberExpressionAst memberAst, TypeDefinitionAst psClass, VariableAnalysisDetails analysisDetails)`
	`530`	`+ internal string GetTypeFromMemberExpressionAstHelper(MemberExpressionAst memberAst, TypeDefinitionAst psClass, VariableAnalysisDetails analysisDetails)`
`519`	`531`	`{`
	`532`	`+ //Try to get the type without using psClass first`
`520`	`533`	`Type result = AssignmentTarget.GetTypeFromMemberExpressionAst(memberAst);`
`521`	`534`
	`535`	`+ //If we can't get the type, then it may be that the type of the object being invoked on is a powershell class`
`522`	`536`	`if (result == null && psClass != null && analysisDetails != null)`
`523`	`537`	`{`
`524`	`538`	`result = AssignmentTarget.GetTypeFromMemberExpressionAst(memberAst, analysisDetails, psClass);`
`@@ -1131,7 +1145,7 @@ public object VisitReturnStatement(ReturnStatementAst returnStatementAst)`
`1131`	`1145`	`/// <returns></returns>`
`1132`	`1146`	`public object VisitMemberExpression(MemberExpressionAst memAst)`
`1133`	`1147`	`{`
`1134`		`- return Helper.Instance.GetTypeFromMemberExpressionAstHelper(memAst, myFunction, classes);`
	`1148`	`+ return Helper.Instance.GetTypeFromMemberExpressionAst(memAst, myFunction, classes);`
`1135`	`1149`	`}`
`1136`	`1150`
`1137`	`1151`	`/// <summary>`
`@@ -1141,7 +1155,7 @@ public object VisitMemberExpression(MemberExpressionAst memAst)`
`1141`	`1155`	`/// <returns></returns>`
`1142`	`1156`	`public object VisitInvokeMemberExpression(InvokeMemberExpressionAst invokeAst)`
`1143`	`1157`	`{`
`1144`		`- return Helper.Instance.GetTypeFromMemberExpressionAstHelper(invokeAst, myFunction, classes);`
	`1158`	`+ return Helper.Instance.GetTypeFromMemberExpressionAst(invokeAst, myFunction, classes);`
`1145`	`1159`	`}`
`1146`	`1160`
`1147`	`1161`	`/// <summary>`
Original file line number	Diff line number	Diff line change
`@@ -1205,7 +1205,7 @@ public AssignmentTarget(AssignmentStatementAst ast)`
`1205`	`1205`	`_rightHandSideVariable = new VariableTarget(cmExAst.Expression as VariableExpressionAst);`
`1206`	`1206`	`if (String.Equals((exprAst as VariableExpressionAst).VariablePath.UserPath, "this", StringComparison.OrdinalIgnoreCase))`
`1207`	`1207`	`{`
`1208`		`-`
	`1208`	`+ Constant = SpecialVars.ThisVariable;`
`1209`	`1209`	`}`
`1210`	`1210`	`}`
`1211`	`1211`	`//Store the type info for variable assignment from .Net type`