Save last element in stackframes for stacktraces (#1133)

Author: Frotty

de.peeeq.wurstscript/src/main/java/de/peeeq/wurstscript/intermediatelang/interpreter/EvaluateExpr.java

@@ -22,6 +22,10 @@
 
 public class EvaluateExpr {
 
+    private static void mark(Element e, ProgramState globalState) {
+        globalState.setLastElement(e);
+    }
+
     public static ILconst eval(ImBoolVal e, ProgramState globalState, LocalState localState) {
         return ILconstBool.instance(e.getValB());
     }
@@ -31,6 +35,8 @@ public static ILconst eval(ImFuncRef e, ProgramState globalState, LocalState loc
     }
 
     public static @Nullable ILconst eval(ImFunctionCall e, ProgramState globalState, LocalState localState) {
+        mark(e, globalState);
+
         ImFunction f = e.getFunc();
         ImExprs arguments = e.getArguments();
 
@@ -191,6 +197,7 @@ public static ILconst eval(ImVarArrayAccess e, ProgramState globalState, LocalSt
                                          ProgramState globalState, LocalState localState) {
         ILconstObject receiver = globalState.toObject(mc.getReceiver().evaluate(globalState, localState));
         globalState.assertAllocated(receiver, mc.attrTrace());
+        mark(mc, globalState);
 
         List<ImExpr> args = mc.getArguments();
 

de.peeeq.wurstscript/src/main/java/de/peeeq/wurstscript/intermediatelang/interpreter/ILInterpreter.java

@@ -97,6 +97,9 @@ public static LocalState runFunc(ProgramState globalState, ImFunction f, @Nullab
                 if (args.length > 0 && args[0] instanceof ILconstObject) {
                     receiverObj = (ILconstObject) args[0];
                 }
+                if (caller != null) {
+                    globalState.setLastElement(caller);
+                }
                 WPos pos = (caller != null) ? caller.attrTrace().attrErrorPos() : f.attrTrace().attrErrorPos();
                 globalState.pushStackframeWithTypes(f, receiverObj, args, pos, normalized);
                 try {
@@ -174,7 +177,9 @@ public static LocalState runFunc(ProgramState globalState, ImFunction f, @Nullab
                 normalized.put(e.getKey(), rhs);
             }
 
-            // --- single push/pop responsibility ---
+            if (caller != null) {
+                globalState.setLastElement(caller);
+            }
             WPos pos = (caller != null) ? caller.attrTrace().attrErrorPos() : f.attrTrace().attrErrorPos();
             globalState.pushStackframeWithTypes(f, receiverObj, args, pos, normalized);
 
@@ -226,16 +231,36 @@ public static de.peeeq.wurstscript.ast.Element getTrace(ProgramState globalState
 
     public static String buildStacktrace(ProgramState globalState, Throwable e) {
         StringBuilder err = new StringBuilder();
+
         try {
-            WPos src = globalState.getLastStatement().attrTrace().attrSource();
-            err.append("Trace : ").append(new File(src.getFile()).getName()).append(":").append(src.getLine()).append("\n");
-        } catch (Exception _e) {
+            ILStackFrame top = globalState.getStackFrames().getStackFrames().isEmpty()
+                ? null
+                : globalState.getStackFrames().getStackFrames().get(0);
+
+            WPos src = null;
+            if (top != null) {
+                src = top.getCurrentSourcePos();
+            }
+            if (src == null && globalState.getLastStatement() != null) {
+                src = globalState.getLastStatement().attrTrace().attrSource();
+            }
+
+            if (src != null) {
+                err.append("Trace : ")
+                    .append(new File(src.getFile()).getName())
+                    .append(":")
+                    .append(src.getLine())
+                    .append("\n");
+            }
+        } catch (Exception ignored) {
             // ignore
         }
+
         globalState.getStackFrames().appendTo(err);
         return err.toString();
     }
 
+
     @SuppressWarnings("null")
     private static ILconst adjustTypeOfConstant(@Nullable ILconst retVal, ImType expectedType) {
         if (retVal instanceof ILconstInt && isTypeReal(expectedType)) {

de.peeeq.wurstscript/src/main/java/de/peeeq/wurstscript/intermediatelang/interpreter/ILStackFrame.java

@@ -13,14 +13,17 @@
 import java.util.Map;
 
 public class ILStackFrame {
-
     public final Either<ImFunction, ImCompiletimeExpr> f;
     public final ILconst[] args;
     public final WPos trace;
     public final @Nullable ILconstObject receiver;
     public final Map<ImTypeVar, ImType> typeSubstitutions;
 
-    public ILStackFrame(ImFunction f, @Nullable ILconstObject receiver, ILconst[] args2, WPos trace, Map<ImTypeVar, ImType> typeSubstitutions) {
+    // last executed element *within this frame*
+    public @Nullable de.peeeq.wurstscript.jassIm.Element currentElement;
+
+    public ILStackFrame(ImFunction f, @Nullable ILconstObject receiver, ILconst[] args2, WPos trace,
+                        Map<ImTypeVar, ImType> typeSubstitutions) {
         this.f = Either.left(f);
         this.receiver = receiver;
         this.args = args2;
@@ -36,35 +39,40 @@ public ILStackFrame(ImCompiletimeExpr f, WPos trace) {
         this.typeSubstitutions = Collections.emptyMap();
     }
 
+    public @Nullable WPos getCurrentSourcePos() {
+        if (currentElement != null) {
+            try {
+                return currentElement.attrTrace().attrSource();
+            } catch (Exception ignored) {}
+        }
+        return trace;
+    }
+
     public String getMessage() {
         StringBuilder sb = new StringBuilder();
-        if (trace != null && !trace.isArtificial()) {
-            String file = new File(trace.getFile()).getName();
-            sb.append("    ╚ ").append(file).append(":").append(trace.getLine());
+
+        WPos pos = getCurrentSourcePos();
+        if (pos != null && !pos.isArtificial()) {
+            String file = new File(pos.getFile()).getName();
+            sb.append("    ╚ ").append(file).append(":").append(pos.getLine());
         }
+
         if (f.isLeft()) {
-            sb.append(" calling ").append(f.getLeft().getName()).append("(");
-            boolean first = true;
-            for (ILconst arg : args) {
-                if (!first) {
-                    sb.append(", ");
-                }
-                sb.append(arg);
-                first = false;
+            sb.append(" inside call ").append(f.getLeft().getName()).append("(");
+            for (int i = 0; i < args.length; i++) {
+                if (i > 0) sb.append(", ");
+                sb.append(args[i]);
             }
             sb.append(")");
         } else {
             sb.append("... when executing compiletime expression ");
         }
-
         return sb.toString();
     }
 
     public CompileError makeCompileError() {
-        return new CompileError(trace, getMessage());
-    }
-
-    public WPos getTrace() {
-        return trace;
+        // Use current element position if available:
+        WPos pos = getCurrentSourcePos();
+        return new CompileError(pos != null ? pos : trace, getMessage());
     }
 }

de.peeeq.wurstscript/src/main/java/de/peeeq/wurstscript/intermediatelang/interpreter/ProgramState.java

@@ -118,8 +118,18 @@ private void identifyGenericStaticGlobals() {
         }
     }
 
+    public void setLastElement(de.peeeq.wurstscript.jassIm.Element e) {
+        lastStatement = e;
+
+        ILStackFrame top = stackFrames.peek();
+        if (top != null) {
+            top.currentElement = e;
+        }
+    }
+
+    // keep old API, delegate:
     public void setLastStatement(ImStmt s) {
-        lastStatement = s;
+        setLastElement(s);
     }
 
     public de.peeeq.wurstscript.jassIm.Element getLastStatement() {