GP-3161: Some emulation framework improvements.

Ghidra/Features/SystemEmulation/ghidra_scripts/DemoPcodeUseropLibrary.java

@@ -99,7 +99,7 @@ public class DemoPcodeUseropLibrary extends AnnotatedPcodeUseropLibrary<byte[]>
 	 */
 	public class DemoStructuredPart extends StructuredSleigh {
 		final Var RAX = lang("RAX", type("long"));
-		final Var RCX = lang("RAX", type("byte *"));
+		final Var RCX = lang("RCX", type("byte *"));
 		final UseropDecl emu_swi = userop(type("void"), "emu_swi", List.of());
 
 		protected DemoStructuredPart(CompilerSpec cs) {

Ghidra/Features/SystemEmulation/src/main/java/ghidra/pcode/struct/AssignStmt.java

@@ -22,7 +22,7 @@ import ghidra.program.model.data.DataType;
  * An assignment statement
  */
 class AssignStmt extends AbstractStmt implements RValInternal, StmtWithVal {
-	private final LValInternal lhs;
+	final LValInternal lhs;
 	private final RValInternal rhs;
 	private final DataType type;
 
@@ -51,9 +51,9 @@ class AssignStmt extends AbstractStmt implements RValInternal, StmtWithVal {
 	@Override
 	protected StringTree generate(Label next, Label fall) {
 		StringTree st = new StringTree();
-		st.append(lhs.generate());
+		st.append(lhs.generate(this));
 		st.append(" = ");
-		st.append(rhs.generate());
+		st.append(rhs.generate(this));
 		st.append(";\n");
 		st.append(next.genGoto(fall));
 		return st;
@@ -65,7 +65,7 @@ class AssignStmt extends AbstractStmt implements RValInternal, StmtWithVal {
 	}
 
 	@Override
-	public String generate() {
-		return lhs.generate();
+	public StringTree generate(RValInternal parent) {
+		return lhs.generate(this);
 	}
 }

Ghidra/Features/SystemEmulation/src/main/java/ghidra/pcode/struct/BinExpr.java

@@ -41,7 +41,15 @@ class BinExpr extends Expr {
 	}
 
 	@Override
-	public String generate() {
-		return "(" + lhs.generate() + " " + op + " " + rhs.generate() + ")";
+	public StringTree generate(RValInternal parent) {
+		StringTree st = new StringTree();
+		st.append("(");
+		st.append(lhs.generate(this));
+		st.append(" ");
+		st.append(op);
+		st.append(" ");
+		st.append(rhs.generate(this));
+		st.append(")");
+		return st;
 	}
 }

Ghidra/Features/SystemEmulation/src/main/java/ghidra/pcode/struct/CallExpr.java

@@ -64,8 +64,21 @@ public class CallExpr extends Expr {
 	}
 
 	@Override
-	public String generate() {
-		return userop.getName() + "(" +
-			args.stream().map(a -> a.generate()).collect(Collectors.joining(",")) + ")";
+	public StringTree generate(RValInternal parent) {
+		StringTree st = new StringTree();
+		st.append(userop.getName());
+		st.append("(");
+		boolean first = false;
+		for (RValInternal a : args) {
+			if (!first) {
+				first = true;
+			}
+			else {
+				st.append(",");
+			}
+			st.append(a.generate(this));
+		}
+		st.append(")");
+		return st;
 	}
 }

Ghidra/Features/SystemEmulation/src/main/java/ghidra/pcode/struct/DefaultVar.java

@@ -114,7 +114,7 @@ class DefaultVar implements LValInternal, Var {
 	}
 
 	@Override
-	public String generate() {
-		return name;
+	public StringTree generate(RValInternal parent) {
+		return StringTree.single(name);
 	}
 }

Ghidra/Features/SystemEmulation/src/main/java/ghidra/pcode/struct/DerefExpr.java

@@ -45,10 +45,29 @@ class DerefExpr extends Expr implements LValInternal {
 	}
 
 	@Override
-	public String generate() {
-		String spacePiece =
-			ctx.language.getDefaultSpace() == space ? "" : ("[" + space.getName() + "]");
-		String sizePiece = type.getLength() == 0 ? "" : (":" + type.getLength());
-		return "(*" + spacePiece + sizePiece + " " + addr.generate() + ")";
+	public StringTree generate(RValInternal parent) {
+		StringTree st = new StringTree();
+		boolean useParens = !(parent instanceof AssignStmt as && as.lhs == this);
+		if (useParens) {
+			st.append("(*");
+		}
+		else {
+			st.append("*");
+		}
+		if (ctx.language.getDefaultSpace() != space) {
+			st.append("[");
+			st.append(space.getName());
+			st.append("]");
+		}
+		if (type.getLength() != 0) {
+			st.append(":");
+			st.append(Integer.toString(type.getLength()));
+		}
+		st.append(" ");
+		st.append(addr.generate(this));
+		if (useParens) {
+			st.append(")");
+		}
+		return st;
 	}
 }

Ghidra/Features/SystemEmulation/src/main/java/ghidra/pcode/struct/FieldExpr.java

@@ -19,12 +19,12 @@ import ghidra.pcode.struct.StructuredSleigh.LVal;
 import ghidra.program.model.data.*;
 
 class FieldExpr extends Expr implements LValInternal {
-	private final RValInternal parent;
+	private final RValInternal composite;
 	private final int offset;
 
-	private FieldExpr(StructuredSleigh ctx, RValInternal parent, int offset, DataType type) {
+	private FieldExpr(StructuredSleigh ctx, RValInternal composite, int offset, DataType type) {
 		super(ctx, type);
-		this.parent = parent;
+		this.composite = composite;
 		this.offset = offset;
 	}
 
@@ -38,16 +38,22 @@ class FieldExpr extends Expr implements LValInternal {
 
 	@Override
 	public LVal cast(DataType type) {
-		return new FieldExpr(ctx, parent, offset, type);
+		return new FieldExpr(ctx, composite, offset, type);
 	}
 
 	@Override
 	public String toString() {
-		return "<Field " + parent + " + 0x" + Long.toString(offset, 16) + ">";
+		return "<Field " + composite + " + 0x" + Long.toString(offset, 16) + ">";
 	}
 
 	@Override
-	public String generate() {
-		return "(" + parent.generate() + " + " + offset + ")";
+	public StringTree generate(RValInternal parent) {
+		StringTree st = new StringTree();
+		st.append("(");
+		st.append(composite.generate(this));
+		st.append(" + ");
+		st.append(Integer.toString(offset));
+		st.append(")");
+		return st;
 	}
 }

Ghidra/Features/SystemEmulation/src/main/java/ghidra/pcode/struct/GotoStmt.java

@@ -19,7 +19,6 @@ import ghidra.pcode.struct.StructuredSleigh.Label;
 import ghidra.pcode.struct.StructuredSleigh.RVal;
 
 public class GotoStmt extends AbstractStmt {
-
 	private final RValInternal target;
 
 	protected GotoStmt(StructuredSleigh ctx, RVal target) {
@@ -31,9 +30,8 @@ public class GotoStmt extends AbstractStmt {
 	protected StringTree generate(Label next, Label fall) {
 		StringTree st = new StringTree();
 		st.append("goto [");
-		st.append(target.generate());
+		st.append(target.generate(null));
 		st.append("];\n");
 		return st;
 	}
-
 }

Ghidra/Features/SystemEmulation/src/main/java/ghidra/pcode/struct/IndexExpr.java

@@ -46,7 +46,15 @@ class IndexExpr extends Expr implements LValInternal {
 	}
 
 	@Override
-	public String generate() {
-		return "(" + base.generate() + " + (" + index.generate() + "*" + elemLen + "))";
+	public StringTree generate(RValInternal parent) {
+		StringTree st = new StringTree();
+		st.append("(");
+		st.append(base.generate(this));
+		st.append(" + (");
+		st.append(index.generate(this));
+		st.append("*");
+		st.append(Integer.toString(elemLen));
+		st.append("))");
+		return st;
 	}
 }

Ghidra/Features/SystemEmulation/src/main/java/ghidra/pcode/struct/LiteralExpr.java

@@ -39,7 +39,7 @@ class LiteralExpr extends Expr {
 	}
 
 	@Override
-	public String generate() {
-		return "0x" + Long.toHexString(val) + ":" + size;
+	public StringTree generate(RValInternal parent) {
+		return StringTree.single(String.format("0x%x:%d", val, size));
 	}
 }

Ghidra/Features/SystemEmulation/src/main/java/ghidra/pcode/struct/RValInternal.java

@@ -26,7 +26,7 @@ interface RValInternal extends RVal {
 	@Override
 	DataType getType();
 
-	String generate();
+	StringTree generate(RValInternal parent);
 
 	@Override
 	default LVal deref() {

Ghidra/Features/SystemEmulation/src/main/java/ghidra/pcode/struct/RawExpr.java

@@ -37,7 +37,14 @@ public class RawExpr extends Expr {
 	}
 
 	@Override
-	public String generate() {
-		return "(" + expr + ")";
+	public StringTree generate(RValInternal parent) {
+		if (parent instanceof AssignStmt as && as.lhs == this) {
+			return StringTree.single(expr);
+		}
+		StringTree st = new StringTree();
+		st.append("(");
+		st.append(expr);
+		st.append(")");
+		return st;
 	}
 }

Ghidra/Features/SystemEmulation/src/main/java/ghidra/pcode/struct/ResultStmt.java

@@ -40,7 +40,7 @@ class ResultStmt extends AbstractStmt {
 		StringTree st = new StringTree();
 		st.append(SleighPcodeUseropDefinition.OUT_SYMBOL_NAME);
 		st.append(" = ");
-		st.append(result.generate());
+		st.append(result.generate(null));
 		st.append(";\n");
 		st.append(routine.lReturn.genGoto(fall));
 		return st;

Ghidra/Features/SystemEmulation/src/main/java/ghidra/pcode/struct/ReturnStmt.java

@@ -30,7 +30,7 @@ class ReturnStmt extends AbstractStmt {
 	protected StringTree generate(Label next, Label fall) {
 		StringTree st = new StringTree();
 		st.append("return [");
-		st.append(target.generate());
+		st.append(target.generate(null));
 		st.append("];\n");
 		return st;
 	}

Ghidra/Features/SystemEmulation/src/main/java/ghidra/pcode/struct/StructuredSleigh.java

@@ -94,7 +94,7 @@ import utilities.util.AnnotationUtilities;
  * 	}
  * };
  * 
- * SleighPcodeUseropDefinition<Object> myUserop = ss.generate().get("my_userop");
+ * SleighPcodeUseropDefinition&lt;Object&gt; myUserop = ss.generate().get("my_userop");
  * // To print source
  * myUserop.getLines().forEach(System.out::print);
  * 
@@ -1081,7 +1081,7 @@ public class StructuredSleigh {
 			}
 			StringTree st = new StringTree();
 			st.append("if ");
-			st.append(((RValInternal) cond).generate());
+			st.append(((RValInternal) cond).generate(null));
 			st.append(" ");
 			st.append(genGoto(fall));
 			return st;

Ghidra/Features/SystemEmulation/src/main/java/ghidra/pcode/struct/UnExpr.java

@@ -39,7 +39,12 @@ class UnExpr extends Expr {
 	}
 
 	@Override
-	public String generate() {
-		return "(" + op + u.generate() + ")";
+	public StringTree generate(RValInternal parent) {
+		StringTree st = new StringTree();
+		st.append("(");
+		st.append(op);
+		st.append(u.generate(this));
+		st.append(")");
+		return st;
 	}
 }

Ghidra/Features/SystemEmulation/src/main/java/ghidra/pcode/struct/VoidExprStmt.java

@@ -45,7 +45,7 @@ class VoidExprStmt extends AbstractStmt implements RValInternal, StmtWithVal {
 	@Override
 	protected StringTree generate(Label next, Label fall) {
 		StringTree st = new StringTree();
-		st.append(expr.generate());
+		st.append(expr.generate(this));
 		st.append(";\n");
 		st.append(next.genGoto(fall));
 		return st;
@@ -57,7 +57,7 @@ class VoidExprStmt extends AbstractStmt implements RValInternal, StmtWithVal {
 	}
 
 	@Override
-	public String generate() {
-		return ctx.nil.generate();
+	public StringTree generate(RValInternal parent) {
+		return ctx.nil.generate(this);
 	}
 }

Ghidra/Framework/Emulation/src/main/java/ghidra/pcode/emu/DefaultPcodeThread.java

@@ -355,7 +355,10 @@ public class DefaultPcodeThread<T> implements PcodeThread<T> {
 	@Override
 	public void overrideContextWithDefault() {
 		if (contextreg != Register.NO_CONTEXT) {
-			overrideContext(defaultContext.getDefaultValue(contextreg, counter));
+			RegisterValue defaultValue = defaultContext.getDefaultValue(contextreg, counter);
+			if (defaultValue != null) {
+				overrideContext(defaultValue);
+			}
 		}
 	}