From 9264c94f6bd2b7075f11b32a875dc16234df2003 Mon Sep 17 00:00:00 2001
From: Ian Piumarta <piumarta@gmail.com>
Date: Sun, 26 Jan 2025 11:38:27 +0900
Subject: [PATCH] handle comparison of integer and pointer to variable

---
 demofiles/dangling-pointer.c |  2 +-
 main.leg                     | 35 ++++++++++++++++++++++++-----------
 2 files changed, 25 insertions(+), 12 deletions(-)

diff --git a/demofiles/dangling-pointer.c b/demofiles/dangling-pointer.c
index 8d17ac9..e09c2bb 100644
--- a/demofiles/dangling-pointer.c
+++ b/demofiles/dangling-pointer.c
@@ -11,7 +11,7 @@ int *alloc() {
 
 int main() {
   int *ptr = alloc();
-  assert(ptr);
+  assert(ptr != 0);
   *ptr = 42;
   printf("%d\n", *ptr);
   return 0;
diff --git a/main.leg b/main.leg
index 6fccd94..f8ebe9e 100644
--- a/main.leg
+++ b/main.leg
@@ -1,6 +1,6 @@
 # main.leg -- C parser + interpreter
 #
-# Last edited: 2025-01-25 09:19:51 by piumarta on m1mbp
+# Last edited: 2025-01-26 11:37:20 by piumarta on zora
 
 %{
 ;
@@ -149,6 +149,9 @@ union Object
 # undef _
 };
 
+void println(oop obj);
+char *toString(oop obj);
+
 int opt_O = 0; // optimise (use VM)
 int opt_v = 0; // verbose (print eval output, parser output, compiled code)
 int opt_x = 0; // disable execution
@@ -300,7 +303,7 @@ long integerValue(oop obj)
 	case Float:	return _floatValue(obj);
 	default: 	break;
     }
-    fatal("cannot convert %s to integer", getTypeName(obj));
+    fatal("cannot convert %s to integer: %s", getTypeName(obj), toString(obj));
     return 0;
 }
 
@@ -594,9 +597,6 @@ CTOR1(Return, value);
 CTOR0(Continue);
 CTOR0(Break);
 
-void println(oop obj);
-char *toString(oop obj);
-
 oop newTbase(char *name, int size, base_t type)
 {
     oop obj = new(Tbase);
@@ -1041,6 +1041,11 @@ oop toStringOn(oop obj, oop str)
 	    String_append(str, ')');
 	    break;
 	}
+	case Reference: {
+	    String_append(str, '&');
+	    toStringOn(get(obj, Reference,target), str);
+	    break;
+	}
 	case Variable: {
 	    oop type = get(obj, Variable,type);
 	    oop name = get(obj, Variable,name);
@@ -2008,8 +2013,16 @@ oop eval(oop exp, oop env)
 			    case LE: 	return IRELOP(lhs, <=, rhs);
 			    case GE: 	return IRELOP(lhs, >=, rhs);
 			    case GT: 	return IRELOP(lhs, > , rhs);
-			    case EQ: 	return IRELOP(lhs, == , rhs);
-			    case NE: 	return IRELOP(lhs, !=, rhs);
+			    case EQ: {
+				if (is(Reference,lhs) && is(Integer,rhs) && _integerValue(rhs) == 0) return false;
+				if (is(Reference,rhs) && is(Integer,lhs) && _integerValue(lhs) == 0) return false;
+				return IRELOP(lhs, == , rhs);
+			    }
+			    case NE: {
+				if (is(Reference,lhs) && is(Integer,rhs) && _integerValue(rhs) == 0) return true;
+				if (is(Reference,rhs) && is(Integer,lhs) && _integerValue(lhs) == 0) return true;
+				return IRELOP(lhs, !=, rhs);
+			    }
 			    case BAND: 	return IBINOP(lhs, & , rhs);
 			    case BXOR: 	return IBINOP(lhs, ^ , rhs);
 			    case BOR: 	return IBINOP(lhs, | , rhs);
@@ -2889,7 +2902,7 @@ oop typeCheck(oop exp, oop fntype)
 		case GE: 	assert(!"unimplemented"); 	break;
 		case GT: 	return t_int;
 		case EQ: 	return t_int;
-		case NE: 	assert(!"unimplemented"); 	break;
+		case NE: 	return t_int;
 		case BAND: 	assert(!"unimplemented"); 	break;
 		case BXOR: 	assert(!"unimplemented"); 	break;
 		case BOR: 	assert(!"unimplemented"); 	break;
@@ -2969,7 +2982,7 @@ oop typeCheck(oop exp, oop fntype)
 	    oop parameters = get(exp, Function,parameters);
 	    oop body       = get(exp, Function,body      );
 	    oop ptypes     = newArray();
-	    if (t_etc == Array_last(parameters)) {
+	    if (Array_size(parameters) && t_etc == Array_last(parameters)) {
 		Array_popLast(parameters);
 		set(exp, Function,variadic, 1);
 	    }
@@ -3022,8 +3035,8 @@ oop typeCheck(oop exp, oop fntype)
 		oop arg  = argv[i];
 		oop argt = typeCheck(arg, fntype);
 		if (argt != part)
-		    fatal("cannot pass argument of type '%s' to parameter of type '%s' ",
-			  toString(argt), toString(part));
+		    fatal("cannot pass argument of type '%s' to parameter of type '%s': %s ",
+			  toString(argt), toString(part), toString(exp));
 	    }
 	    return get(tfunc, Tfunction,result);
 	}