Merge remote-tracking branch 'origin/GT-3145_OverrideExternalRef' into Ghidra_9.1

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

@@ -4470,6 +4470,8 @@ void FuncCallSpecs::deindirect(Funcdata &data,Funcdata *newfd)
   Varnode *vn = data.newVarnodeCallSpecs(this);
   data.opSetInput(op,vn,0);
   data.opSetOpcode(op,CPUI_CALL);
+  if (isOverride())	// If we are overridden at the call-site
+    return;		// Don't use the discovered function prototype
 
   // Try our best to merge existing prototype
   // with the one we have just been handed

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

@@ -1158,7 +1158,8 @@ class FuncProto {
     unknown_model = 512,	///< Set if the PrototypeModel isn't known
     is_constructor = 0x400,	///< Function is an (object-oriented) constructor
     is_destructor = 0x800,	///< Function is an (object-oriented) destructor
-    has_thisptr= 0x1000		///< Function is a method with a 'this' pointer as an argument
+    has_thisptr= 0x1000,	///< Function is a method with a 'this' pointer as an argument
+    is_override = 0x2000	///< Set if \b this prototype is created to override a single call site
   };
   ProtoModel *model;		///< Model of for \b this prototype
   ProtoStore *store;		///< Storage interface for parameters
@@ -1332,6 +1333,8 @@ public:
   bool isStackGrowsNegative(void) const { return model->isStackGrowsNegative(); }	///< Return \b true if the stack grows toward smaller addresses
   bool isDotdotdot(void) const { return ((flags&dotdotdot)!=0); }	///< Return \b true if \b this takes a variable number of arguments
   void setDotdotdot(bool val) { flags = val ? (flags|dotdotdot) : (flags & ~((uint4)dotdotdot)); }	///< Toggle whether \b this takes variable arguments
+  bool isOverride(void) const { return ((flags&is_override)!=0); }	///< Return \b true if \b this is a call site override
+  void setOverride(bool val) { flags = val ? (flags|is_override) : (flags & ~((uint4)is_override)); }	///< Toggle whether \b this is a call site override
   uint4 hasEffect(const Address &addr,int4 size) const;
   vector<EffectRecord>::const_iterator effectBegin(void) const;	///< Get iterator to front of EffectRecord list
   vector<EffectRecord>::const_iterator effectEnd(void) const;	///< Get iterator to end of EffectRecord list

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

@@ -117,7 +117,8 @@ void Override::insertProtoOverride(const Address &callpoint,FuncProto *p)
   if (iter != protoover.end())	// Check for pre-existing override
     delete (*iter).second;	// and delete it
 
-  protoover[callpoint] = p;
+  p->setOverride(true);		// Mark this as an override
+  protoover[callpoint] = p;	// Take ownership of the object
 }
 
 /// \brief Flag an indirect jump for multistage analysis

Ghidra/Features/Decompiler/src/main/java/ghidra/app/plugin/core/decompile/actions/OverridePrototypeAction.java

@@ -29,6 +29,7 @@ import ghidra.program.model.address.Address;
 import ghidra.program.model.data.*;
 import ghidra.program.model.listing.*;
 import ghidra.program.model.pcode.*;
+import ghidra.program.model.symbol.Reference;
 import ghidra.util.Msg;
 import ghidra.util.UndefinedFunction;
 import ghidra.util.exception.CancelledException;
@@ -140,7 +141,22 @@ public class OverridePrototypeAction extends AbstractDecompilerAction {
 		}
 		Address addr = op.getInput(0).getAddress();
 		Program program = controller.getProgram();
-		return program.getFunctionManager().getFunctionAt(addr);
+		FunctionManager functionManager = program.getFunctionManager();
+		Function function = functionManager.getFunctionAt(addr);
+		if (function != null) {
+			return function;
+		}
+		Address opAddr = op.getSeqnum().getTarget();
+		Reference[] references = program.getReferenceManager().getFlowReferencesFrom(opAddr);
+		for (Reference ref : references) {
+			if (ref.getReferenceType().isCall()) {
+				function = functionManager.getFunctionAt(ref.getToAddress());
+				if (function != null) {
+					return function;
+				}
+			}
+		}
+		return null;
 	}
 
 	private String generateSignature(PcodeOp op, String name) {