HighSymbol support for isThis and isHidden properties

Ghidra/Features/Decompiler/src/decompile/cpp/database.cc

@@ -362,6 +362,8 @@ void Symbol::saveXmlHeader(ostream &s) const
     a_v_b(s,"hiddenretparm",true);
   if ((dispflags&isolate)!=0)
     a_v_b(s,"merge",false);
+  if ((dispflags&is_this_ptr)!=0)
+    a_v_b(s,"thisptr",true);
   int4 format = getDisplayFormat();
   if (format != 0) {
     s << " format=\"";
@@ -461,6 +463,10 @@ void Symbol::restoreXmlHeader(const Element *el)
 	  if (xml_readbool(el->getAttributeValue(i)))
 	    flags |= Varnode::typelock;
 	}
+	else if (attName == "thisptr") {
+	  if (xml_readbool(el->getAttributeValue(i)))
+	    dispflags |= is_this_ptr;
+	}
 	break;
       case 'v':
 	if (attName == "volatile") {

Ghidra/Features/Decompiler/src/decompile/cpp/database.hh

@@ -183,7 +183,8 @@ public:
     force_char = 5,		///< Force integer to be printed as a character constant
     size_typelock = 8,	        ///< Only the size of the symbol is typelocked
     isolate = 16,		///< Symbol should not speculatively merge automatically
-    merge_problems = 32		///< Set if some SymbolEntrys did not get merged
+    merge_problems = 32,	///< Set if some SymbolEntrys did not get merged
+    is_this_ptr = 64		///< We are the "this" symbol for a class method
   };
 
   Symbol(Scope *sc,const string &nm,Datatype *ct);	///< Construct given a name and data-type
@@ -198,6 +199,7 @@ public:
   bool isTypeLocked(void) const { return ((flags&Varnode::typelock)!=0); }	///< Is the Symbol type-locked
   bool isNameLocked(void) const { return ((flags&Varnode::namelock)!=0); }	///< Is the Symbol name-locked
   bool isSizeTypeLocked(void) const { return ((dispflags & size_typelock)!=0); }	///< Is the Symbol size type-locked
+  bool isThisPointer(void) const { return ((dispflags & is_this_ptr)!=0); }		///< Is \b this the "this" pointer
   bool isIndirectStorage(void) const { return ((flags&Varnode::indirectstorage)!=0); }	///< Is storage really a pointer to the true Symbol
   bool isHiddenReturn(void) const { return ((flags&Varnode::hiddenretparm)!=0); }	///< Is this a reference to the function return value
   bool isNameUndefined(void) const;				///< Does \b this have an undefined name

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/pcode/HighSymbol.java

@@ -17,10 +17,11 @@ package ghidra.program.model.pcode;
 
 import ghidra.program.model.address.Address;
 import ghidra.program.model.data.DataType;
-import ghidra.program.model.listing.Program;
-import ghidra.program.model.listing.VariableStorage;
+import ghidra.program.model.lang.DynamicVariableStorage;
+import ghidra.program.model.listing.*;
 import ghidra.program.model.symbol.Namespace;
 import ghidra.program.model.symbol.Symbol;
+import ghidra.util.exception.InvalidInputException;
 import ghidra.util.xml.SpecXmlUtils;
 import ghidra.xml.XmlElement;
 import ghidra.xml.XmlPullParser;
@@ -40,6 +41,8 @@ public class HighSymbol {
 	protected int categoryIndex;		// Numbering within the sub-class
 	private boolean namelock;		// Is this variable's name locked
 	private boolean typelock;		// Is this variable's datatype locked
+	private boolean isThis;			// True if we are "this" symbol for function method call
+	private boolean isHidden;		// True if we are hidden symbol containing pointer to where return value is stored
 	private long id;				// Unique id of this symbol
 	protected SymbolEntry[] entryList;	// List of mappings for this symbol
 	
@@ -53,6 +56,8 @@ public class HighSymbol {
 	protected HighSymbol(HighFunction func) {
 		function = func;
 		dtmanage = function.getDataTypeManager();
+		isThis = false;
+		isHidden = false;
 	}
 
 	/**
@@ -69,6 +74,8 @@ public class HighSymbol {
 		type = tp;
 		namelock = false;
 		typelock = false;
+		isThis = false;
+		isHidden = false;
 		id = uniqueId;
 		category = -1;
 		categoryIndex = -1;
@@ -92,6 +99,8 @@ public class HighSymbol {
 		type = tp;
 		namelock = nlock;
 		typelock = tlock;
+		isThis = false;
+		isHidden = false;
 		id = uniqueId;
 		category = -1;
 		categoryIndex = -1;
@@ -101,6 +110,15 @@ public class HighSymbol {
 		if (entryList == null) {
 			entryList = new SymbolEntry[1];
 			entryList[0] = entry;
+			if (entry.getStorage().isAutoStorage()) {
+				AutoParameterType autoType = entry.getStorage().getAutoParameterType();
+				if (autoType == AutoParameterType.THIS) {
+					isThis = true;
+				}
+				else if (autoType == AutoParameterType.RETURN_STORAGE_PTR) {
+					isHidden = true;
+				}
+			}
 		}
 		else {
 			SymbolEntry[] newList = new SymbolEntry[entryList.length + 1];
@@ -316,6 +334,20 @@ public class HighSymbol {
 		return false;
 	}
 
+	/**
+	 * @return true if symbol is a "this" pointer for a class method
+	 */
+	public boolean isThisPointer() {
+		return isThis;
+	}
+
+	/**
+	 * @return true is symbol holds a pointer to where a function's return value should be stored
+	 */
+	public boolean isHiddenReturn() {
+		return isHidden;
+	}
+
 	/**
 	 * @return the first mapping object attached to this symbol
 	 */
@@ -349,6 +381,12 @@ public class HighSymbol {
 		if (isIsolated()) {
 			SpecXmlUtils.encodeBooleanAttribute(buf, "merge", false);
 		}
+		if (isThis) {
+			SpecXmlUtils.encodeBooleanAttribute(buf, "thisptr", true);
+		}
+		if (isHidden) {
+			SpecXmlUtils.encodeBooleanAttribute(buf, "hiddenretparm", true);
+		}
 		SpecXmlUtils.encodeSignedIntegerAttribute(buf, "cat", category);
 		if (categoryIndex >= 0) {
 			SpecXmlUtils.encodeSignedIntegerAttribute(buf, "index", categoryIndex);
@@ -382,6 +420,16 @@ public class HighSymbol {
 		if ((namelockstr != null) && (SpecXmlUtils.decodeBoolean(namelockstr))) {
 			namelock = true;
 		}
+		isThis = false;
+		String thisstring = symel.getAttribute("thisptr");
+		if ((thisstring != null) && (SpecXmlUtils.decodeBoolean(thisstring))) {
+			isThis = true;
+		}
+		isHidden = false;
+		String hiddenstring = symel.getAttribute("hiddenretparm");
+		if ((hiddenstring != null) && (SpecXmlUtils.decodeBoolean(hiddenstring))) {
+			isHidden = true;
+		}
 //		isolate = false;
 //		String isolatestr = symel.getAttribute("merge");
 //		if ((isolatestr != null) && !SpecXmlUtils.decodeBoolean(isolatestr)) {
@@ -431,6 +479,20 @@ public class HighSymbol {
 			entry.restoreXML(parser);
 			addMapEntry(entry);
 		}
+		if ((isThis || isHidden) && entryList != null) {
+			SymbolEntry entry = entryList[0];
+			VariableStorage storage = entry.getStorage();
+			AutoParameterType autoType =
+				isThis ? AutoParameterType.THIS : AutoParameterType.RETURN_STORAGE_PTR;
+			try {
+				VariableStorage newStorage = new DynamicVariableStorage(storage.getProgram(),
+					autoType, storage.getFirstVarnode());
+				entryList[0] = new MappedEntry(this, newStorage, entry.getPCAdress());
+			}
+			catch (InvalidInputException e) {
+				throw new PcodeXMLException("Unable to parse auto-parameter");
+			}
+		}
 	}
 
 	/**