Merge remote-tracking branch 'origin/GT-3647-dragonmacher-find-datatypes-fix'

Ghidra/Features/Decompiler/src/main/java/ghidra/app/decompiler/ClangVariableDecl.java

@@ -27,6 +27,7 @@ import ghidra.util.Msg;
 import ghidra.util.xml.SpecXmlUtils;
 import ghidra.xml.XmlElement;
 import ghidra.xml.XmlPullParser;
+
 /**
  * 
  *
@@ -45,21 +46,21 @@ public class ClangVariableDecl extends ClangTokenGroup {
 	}
 
 	public DataType getDataType() {
-		return datatype;	
+		return datatype;
 	}
-	
+
 	public HighVariable getHighVariable() {
 		return typevar;
 	}
-	
+
 	@Override
-    public void restoreFromXML(XmlPullParser parser,PcodeFactory pfactory) {
-	    XmlElement node = parser.peek();
-		super.restoreFromXML(parser,pfactory);
+	public void restoreFromXML(XmlPullParser parser, PcodeFactory pfactory) {
+		XmlElement node = parser.peek();
+		super.restoreFromXML(parser, pfactory);
 		long symref = SpecXmlUtils.decodeLong(node.getAttribute(ClangXML.SYMREF));
 		HighSymbol sym = pfactory.getSymbol(symref);
 		if (sym == null) {
-			Msg.error(this, "Invalid symbol reference: " + symref);
+			Msg.error(this, "Invalid symbol reference: " + symref + " in " + Parent());
 			return;
 		}
 		typevar = sym.getHighVariable();

Ghidra/Features/DecompilerDependent/src/main/java/ghidra/app/extension/datatype/finder/AnonymousVariableAccessDR.java

@@ -45,7 +45,7 @@ import ghidra.program.model.data.DataType;
  * being accessed anonymously, since there is no variable of <code>Foo</code> declared 
  * in the current function. 
  */
-public class AnonymousVariableAccessDR extends DecompilerReference {
+public class AnonymousVariableAccessDR extends VariableAccessDR {
 
 	protected AnonymousVariableAccessDR(ClangLine line, ClangFieldToken token) {
 		super(line, token);
@@ -54,16 +54,40 @@ public class AnonymousVariableAccessDR extends DecompilerReference {
 	@Override
 	public void accumulateMatches(DataType dt, String fieldName, List<DataTypeReference> results) {
 
+		//
+		// This class is backed by a ClangFieldToken.  That class's data type is the composite 
+		// that contains the field being accessed.   A variable being accessed has 2 types being
+		// touched: the aforementioned composite and the type of the field itself.
+		//
+		// This can match in one of two cases:
+		// 1) the client seeks to match a given field inside of the containing composite, or
+		// 2) the client seeks to match only the type, which means that the field type itself must match
+		//
+
 		ClangFieldToken field = (ClangFieldToken) sourceToken;
-		DataType fieldDt = field.getDataType();
-		if (!isEqual(dt, fieldDt)) {
+		DataType compositeType = field.getDataType();
+		DataType fieldDt = DecompilerReference.getFieldDataType(field);
+
+		boolean matchesComposite = isEqual(dt, compositeType);
+		boolean matchesField = isEqual(dt, fieldDt);
+		boolean noMatch = !(matchesComposite || matchesField);
+		if (noMatch) {
 			return;
 		}
 
-		if (field.getText().equals(fieldName)) {
-			results.add(new DataTypeReference(fieldDt, fieldName, getFunction(), getAddress(),
-				getContext()));
+		if (fieldName == null) {
+			// case 2; no field name to check
+			if (matchesField) {
+				results.add(createReference(variable));
+			}
+			return;
+		}
+
+		// case 1; check the field name and the composite type
+		if (matchesComposite && field.getText().equals(fieldName)) {
+			results.add(
+				new DataTypeReference(compositeType, fieldName, getFunction(), getAddress(),
+					getContext()));
 		}
 	}
-
 }

Ghidra/Features/DecompilerDependent/src/main/java/ghidra/app/extension/datatype/finder/DecompilerDataTypeReferenceFinder.java

@@ -461,8 +461,14 @@ public class DecompilerDataTypeReferenceFinder implements DataTypeReferenceFinde
 				return false; // should not happen
 			}
 
+			// Note: the field's type is that of the parent structure, not the field.  We want the
+			//       field's type, so we must retrieve that.
+			DataType fieldDt = DecompilerReference.getFieldDataType(field);
+
+			// unusual code: getDataType() on the variable may return the type of the field being
+			//               accessed.  Contrastingly, getDataType() on the field may return the
+			//               type of the parent structure.
 			DataType variableDt = variable.getDataType();
-			DataType fieldDt = field.getDataType();
 			return !DecompilerReference.isEqual(variableDt, fieldDt);
 		}
 

Ghidra/Features/DecompilerDependent/src/main/java/ghidra/app/extension/datatype/finder/DecompilerReference.java

@@ -18,8 +18,7 @@ package ghidra.app.extension.datatype.finder;
 import java.util.Arrays;
 import java.util.List;
 
-import ghidra.app.decompiler.ClangLine;
-import ghidra.app.decompiler.ClangToken;
+import ghidra.app.decompiler.*;
 import ghidra.app.plugin.core.navigation.locationreferences.ReferenceUtils;
 import ghidra.app.services.DataTypeReference;
 import ghidra.program.model.address.Address;
@@ -103,12 +102,26 @@ public abstract class DecompilerReference {
 	public static boolean isEquivalent(DataType dt1, DataType dt2) {
 		DataType base1 = getBaseType(dt1);
 		DataType base2 = getBaseType(dt2);
+
+		if (base1 == null || base2 == null) {
+			// this should not happen, but we have seen sometimes that ClangVariableDecl
+			// cannot find its HighSymbol from which to get a datatype
+			return false;
+		}
+
 		return base1.isEquivalent(base2);
 	}
 
 	public static boolean isEqual(DataType dt1, DataType dt2) {
 		DataType base1 = getBaseType(dt1);
 		DataType base2 = getBaseType(dt2);
+
+		if (base1 == null || base2 == null) {
+			// this should not happen, but we have seen sometimes that ClangVariableDecl
+			// cannot find its HighSymbol from which to get a datatype
+			return false;
+		}
+
 		return base1.equals(base2);
 	}
 
@@ -129,6 +142,21 @@ public abstract class DecompilerReference {
 		return dt;
 	}
 
+	public static DataType getFieldDataType(ClangFieldToken field) {
+		DataType fieldDt = field.getDataType();
+		fieldDt = DecompilerReference.getBaseType(fieldDt);
+		if (fieldDt instanceof Structure) {
+			Structure parent = (Structure) fieldDt;
+			int offset = field.getOffset();
+			int n = parent.getLength();
+			if (offset >= 0 && offset < n) {
+				DataTypeComponent dtc = parent.getComponentAt(field.getOffset());
+				fieldDt = dtc.getDataType();
+			}
+		}
+		return fieldDt;
+	}
+
 	@Override
 	public String toString() {
 

Ghidra/Features/DecompilerDependent/src/main/java/ghidra/app/extension/datatype/finder/DecompilerVariable.java

@@ -51,6 +51,12 @@ public abstract class DecompilerVariable {
 			return ((ClangTypeToken) variable).getDataType();
 		}
 
+// not sure if we need this; the type returned here is the structure and not the 
+// field's type
+//		if (variable instanceof ClangFieldToken) {
+//			return ((ClangFieldToken) variable).getDataType();
+//		}
+
 		// Note: this is the icky part of the API.  How to know from where to get the data type?
 		HighVariable highVariable = variable.getHighVariable();
 		if (highVariable != null) {

Ghidra/Features/DecompilerDependent/src/main/java/ghidra/app/extension/datatype/finder/VariableAccessDR.java

@@ -39,6 +39,10 @@ public class VariableAccessDR extends DecompilerReference {
 		super(line, null /* This class does not always have a 'type' token */);
 	}
 
+	protected VariableAccessDR(ClangLine line, ClangFieldToken token) {
+		super(line, token);
+	}
+
 	void setVariable(ClangVariableToken token, List<DecompilerVariable> casts) {
 		if (variable != null) {
 			throw new AssertException("Decompiler variable is already set for this access");
@@ -184,7 +188,7 @@ public class VariableAccessDR extends DecompilerReference {
 		return matches;
 	}
 
-	private DataTypeReference createReference(DecompilerVariable var) {
+	protected DataTypeReference createReference(DecompilerVariable var) {
 
 		DataType dataType = var.getDataType();
 		String context = getContext(var);
@@ -263,11 +267,11 @@ public class VariableAccessDR extends DecompilerReference {
 
 		//@formatter:off
 		return "{\n" +
+			"\tline " + getContext() + ",\n" +
+			"\tfunction: " + getFunction() + "\n" +
 			"\tvariable: " + StringUtilities.toStringWithIndent(variable) + ",\n" +
 			"\tdata type: " + getDataType() + ",\n"+ 
 			subFieldsString +
-			"\tline " + getContext() + ",\n" +
-			"\tfunction: " + getFunction() + "\n" +
 		"}";
 		//@formatter:on
 	}