GP-5189 Add range attributes to VarargsFilter

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

@@ -3433,6 +3433,10 @@ void ProtoStoreInternal::decode(Decoder &decoder,ProtoModel *model)
     addressesdetermined = false;
 
   uint4 elemId = decoder.openElement(ELEM_INTERNALLIST);
+  uint4 firstId = decoder.getNextAttributeId();
+  if (firstId == ATTRIB_FIRST) {
+    proto.firstVarArgSlot = decoder.readSignedInteger();
+  }
   for(;;) { // This is only the input params
     uint4 subId = decoder.openElement();		// <retparam> or <param>
     if (subId == 0) break;

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

@@ -412,13 +412,22 @@ bool VarargsFilter::filter(const PrototypePieces &proto,int4 pos) const
 
 {
   if (proto.firstVarArgSlot < 0) return false;
-  return (pos >= proto.firstVarArgSlot);
+  pos -= proto.firstVarArgSlot;
+  return (pos >= firstPos && pos <= lastPos);
 }
 
 void VarargsFilter::decode(Decoder &decoder)
 
 {
   uint4 elemId = decoder.openElement(ELEM_VARARGS);
+  for(;;) {
+    uint4 attribId = decoder.getNextAttributeId();
+    if (attribId == 0) break;
+    if (attribId == ATTRIB_FIRST)
+      firstPos = decoder.readSignedInteger();
+    else if (attribId == ATTRIB_LAST)
+      lastPos = decoder.readSignedInteger();
+  }
   decoder.closeElement(elemId);
 }
 

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

@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *      http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -190,15 +190,24 @@ public:
   virtual void decode(Decoder &decoder) {}
 };
 
-/// \brief A filter that selects function parameters that are considered optional
+/// \brief A filter that selects a range of function parameters that are considered optional.
 ///
 /// If the underlying function prototype is considered to take variable arguments, the first
-/// \e n parameters (as determined by PrototypePieces.firstVarArgSlot) are considered non-optional.
-/// If additional data-types are provided beyond the initial \e n, these are considered optional.
-/// This filter returns \b true for these optional parameters
+/// n parameters (as determined by PrototypePieces.firstVarArgSlot) are considered non-optional.
+///\e  If additional data-types are provided beyond the initial \e n, these are considered optional.
+/// By default this filter matches on any parameter in a prototype with variable arguments.
+/// Optionally, it can filter on a range of parameters that are specified relative to the
+/// first variable argument.
+///   - \<varargs first="0"/>   - matches optional arguments but not non-optional ones.
+///   - \<varargs first="0" last="0"/>  -  matches the first optional argument.
+///   - \<varargs first="-1"/> - matches the last non-optional argument and all optional ones.
 class VarargsFilter : public QualifierFilter {
+  int4 firstPos;			///< Start of range to match (offset relative to first variable arg)
+  int4 lastPos;				///< End of range to match
 public:
-  virtual QualifierFilter *clone(void) const { return new VarargsFilter(); }
+  VarargsFilter(void) { firstPos = 0x80000000; lastPos = 0x7fffffff; }
+  VarargsFilter(int4 first,int4 last) { firstPos = first; lastPos = last; }
+  virtual QualifierFilter *clone(void) const { return new VarargsFilter(firstPos,lastPos); }
   virtual bool filter(const PrototypePieces &proto,int4 pos) const;
   virtual void decode(Decoder &decoder);
 };

Ghidra/Framework/SoftwareModeling/data/languages/compiler_spec.rxg

@@ -355,7 +355,12 @@
     <interleave>
       <optional>
         <element name="varargs">
-          <empty/>
+          <optional>
+            <attribute name="first"/>
+          </optional>
+          <optional>
+            <attribute name="last"/>
+          </optional>
         </element>
       </optional>
       <optional>

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/lang/protorules/VarargsFilter.java

@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *      http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -15,30 +15,54 @@
  */
 package ghidra.program.model.lang.protorules;
 
+import static ghidra.program.model.pcode.AttributeId.*;
 import static ghidra.program.model.pcode.ElementId.*;
 
 import java.io.IOException;
 
 import ghidra.program.model.lang.PrototypePieces;
 import ghidra.program.model.pcode.Encoder;
+import ghidra.util.xml.SpecXmlUtils;
 import ghidra.xml.*;
 
 /**
- * A filter that selects function parameters that are considered optional.
- * If the underlying function prototype is considered to take variable arguments, the first
- * n parameters (as determined by PrototypePieces.firstVarArgSlot) are considered non-optional.
+ * A filter that selects a range of function parameters that are considered optional.
+ * If the underlying function prototype takes variable arguments, the first n
+ * parameters (as determined by PrototypePieces.firstVarArgSlot) are considered non-optional.
  * If additional data-types are provided beyond the initial n, these are considered optional.
- * This filter returns true for these optional parameters
+ * By default this filter matches on all parameters in a prototype with variable arguments.
+ * Optionally, it can filter on a range of parameters that are specified relative to the
+ * first variable argument.
+ *    {@code <varargs first="0"/>}   - matches optional arguments but not non-optional ones.
+ *    {@code <varargs first="0" last="0"/>}  -  matches the first optional argument.
+ *    {@code <varargs first="-1"/>} - matches the last non-optional argument and all optional ones.
  */
 public class VarargsFilter implements QualifierFilter {
+	private int firstPos;		// Range of params to match (relative to first variable arg)
+	private int lastPos;
+
+	public VarargsFilter() {
+		firstPos = Integer.MIN_VALUE;
+		lastPos = Integer.MAX_VALUE;
+	}
+
+	public VarargsFilter(int first, int last) {
+		firstPos = first;
+		lastPos = last;
+	}
+
 	@Override
 	public QualifierFilter clone() {
-		return new VarargsFilter();
+		return new VarargsFilter(firstPos, lastPos);
 	}
 
 	@Override
 	public boolean isEquivalent(QualifierFilter op) {
-		return (this.getClass() == op.getClass());
+		if (this.getClass() != op.getClass()) {
+			return false;
+		}
+		VarargsFilter otherFilter = (VarargsFilter) op;
+		return (firstPos == otherFilter.firstPos && lastPos == otherFilter.lastPos);
 	}
 
 	@Override
@@ -46,18 +70,33 @@ public class VarargsFilter implements QualifierFilter {
 		if (proto.firstVarArgSlot < 0) {
 			return false;
 		}
-		return (pos >= proto.firstVarArgSlot);
+		pos -= proto.firstVarArgSlot;
+		return (pos >= firstPos && pos <= lastPos);
 	}
 
 	@Override
 	public void encode(Encoder encoder) throws IOException {
 		encoder.openElement(ELEM_VARARGS);
+		if (firstPos != Integer.MIN_VALUE) {
+			encoder.writeSignedInteger(ATTRIB_FIRST, firstPos);
+		}
+		if (lastPos != Integer.MAX_VALUE) {
+			encoder.writeSignedInteger(ATTRIB_LAST, lastPos);
+		}
 		encoder.closeElement(ELEM_VARARGS);
 	}
 
 	@Override
 	public void restoreXml(XmlPullParser parser) throws XmlParseException {
 		XmlElement elem = parser.start(ELEM_VARARGS.name());
+		String firstPosString = elem.getAttribute(ATTRIB_FIRST.name());
+		if (firstPosString != null) {
+			firstPos = SpecXmlUtils.decodeInt(firstPosString);
+		}
+		String lastPosString = elem.getAttribute(ATTRIB_LAST.name());
+		if (lastPosString != null) {
+			lastPos = SpecXmlUtils.decodeInt(lastPosString);
+		}
 		parser.end(elem);
 	}
 }

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

@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *      http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -311,9 +311,11 @@ public class FunctionPrototype {
 	 * Encode this function prototype to a stream.
 	 * @param encoder is the stream encoder
 	 * @param dtmanage is the DataTypeManager for building type reference tags
+	 * @param firstVarArg is index of first variable argument or -1
 	 * @throws IOException for errors in the underlying stream
 	 */
-	public void encodePrototype(Encoder encoder, PcodeDataTypeManager dtmanage) throws IOException {
+	public void encodePrototype(Encoder encoder, PcodeDataTypeManager dtmanage, int firstVarArg)
+			throws IOException {
 		encoder.openElement(ELEM_PROTOTYPE);
 		if (extrapop == PrototypeModel.UNKNOWN_EXTRAPOP) {
 			encoder.writeString(ATTRIB_EXTRAPOP, "unknown");
@@ -378,6 +380,10 @@ public class FunctionPrototype {
 		}
 		if (params != null) {
 			encoder.openElement(ELEM_INTERNALLIST);
+			if (firstVarArg >= 0) {
+				// Encoding detail because we are not sending the storage address
+				encoder.writeSignedInteger(ATTRIB_FIRST, firstVarArg);
+			}
 			for (ParameterDefinition param : params) {
 				encoder.openElement(ELEM_PARAM);
 				String name = param.getName();

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

@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *      http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -454,7 +454,7 @@ public class HighFunction extends PcodeSyntaxTree {
 			AddressXML.encode(encoder, entryPoint);		// Address is forced on XML
 		}
 		localSymbols.encodeLocalDb(encoder, namespace, getDataTypeManager().getNameTransformer());
-		proto.encodePrototype(encoder, getDataTypeManager());
+		proto.encodePrototype(encoder, getDataTypeManager(), -1);
 		if ((jumpTables != null) && (jumpTables.size() > 0)) {
 			encoder.openElement(ELEM_JUMPTABLELIST);
 			for (JumpTable jumpTable : jumpTables) {
@@ -466,13 +466,15 @@ public class HighFunction extends PcodeSyntaxTree {
 		if (hasOverrideTag) {
 			encoder.openElement(ELEM_OVERRIDE);
 			PcodeDataTypeManager dtmanage = getDataTypeManager();
+			Program prog = func.getProgram();
 			for (DataTypeSymbol sym : protoOverrides) {
 				Address addr = sym.getAddress();
+				int firstVarArg = HighFunctionDBUtil.getFirstVarArg(prog, addr);
 				FunctionPrototype fproto = new FunctionPrototype(
 					(FunctionSignature) sym.getDataType(), compilerSpec, false);
 				encoder.openElement(ELEM_PROTOOVERRIDE);
 				AddressXML.encode(encoder, addr);
-				fproto.encodePrototype(encoder, dtmanage);
+				fproto.encodePrototype(encoder, dtmanage, firstVarArg);
 				encoder.closeElement(ELEM_PROTOOVERRIDE);
 			}
 			encoder.closeElement(ELEM_OVERRIDE);

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

@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *      http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -739,6 +739,27 @@ public class HighFunctionDBUtil {
 		return datsym;
 	}
 
+	/**
+	 * If there is a call to a function at the given address, and the function takes variable arguments,
+	 * return the index of the first variable argument. Return -1 otherwise.
+	 * @param program is the Program
+	 * @param addr is the given address of the call
+	 * @return the index of the first variable argument or -1
+	 */
+	public static int getFirstVarArg(Program program, Address addr) {
+		for (Reference ref : program.getReferenceManager().getReferencesFrom(addr)) {
+			if (ref.isPrimary() && ref.getReferenceType().isCall()) {
+				Address callDestAddr = ref.getToAddress();
+				Function func = program.getFunctionManager().getFunctionAt(callDestAddr);
+				if (func != null && func.hasVarArgs()) {
+					return func.getParameterCount();
+				}
+				break;
+			}
+		}
+		return -1;
+	}
+
 	/**
 	 * Get the Address referred to by a spacebase reference. Address-of references are encoded in
 	 * the p-code syntax tree as: {@code vn = PTRSUB(<spacebase>, #const)}.  This decodes the reference and

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

@@ -681,7 +681,7 @@ public class PcodeDataTypeManager {
 		encoder.writeSignedInteger(ATTRIB_SIZE, 1);		// Force size of 1
 		CompilerSpec cspec = program.getCompilerSpec();
 		FunctionPrototype fproto = new FunctionPrototype(type, cspec, voidInputIsVarargs);
-		fproto.encodePrototype(encoder, this);
+		fproto.encodePrototype(encoder, this, -1);
 		encoder.closeElement(ELEM_TYPE);
 	}
 

Ghidra/Processors/TI_MSP430/data/languages/TI_MSP430.cspec

@@ -43,6 +43,11 @@
         <pentry maxsize="500" minsize="1" align="1">
           <addr space="stack" offset="2"/>
         </pentry>
+        <rule>
+          <datatype name="any"/>
+          <varargs first="-1"/>
+          <goto_stack/>
+        </rule>
         <rule>
           <datatype name="struct" minsize="1"/>
           <convert_to_ptr/>