Merge pull request #27 from geokoko/26-expressions-in-if-conditions

Fix erroneous rejection of boolean conditions

Author: geokoko

src/frontend/semantic/semantic_pass.cpp

@@ -816,8 +816,14 @@ void SemanticPass::visit(ExprCond& n) {
 	if (auto* expr = n.expression()) {
 		expr->accept(*this);
 	}
-	// Dana does not allow bare expressions as conditions; 
+	// Dana does not allow bare expressions as conditions - except boolean literals; 
 	// conditions must be relational (=, <>, <, >, <=, >=) or logical (and, or, not)
+	// for variables of type byte.
+	if (dynamic_cast<TrueConst*>(n.expression()) ||
+		dynamic_cast<FalseConst*>(n.expression())) {
+		n.setType(makeByteType());
+		return;
+	}
 	context_.diags().report(Diagnostics::Severity::Error, Diagnostics::Phase::Semantic,
 					  n.loc, "bare expression cannot be used as condition");
 	n.setType(makeByteType());

tests/programs/conds.dana

@@ -0,0 +1,24 @@
+def cond
+   var a is byte
+   var x y sum is int
+   x   := 10
+   y   := 0
+   a   := true
+   sum := 0
+   
+   loop:
+      if a = false:
+        break
+      if a = true and x >= y:
+         sum := sum + x * y
+         x := x-1
+      elif true:
+         if y <= 10:
+            x := 10
+         elif not false:
+            a := false
+         y := y + 1
+   if sum = 1705:
+      writeString: "42\n"
+   else:
+     writeString: "wrong!!!\n"

tests/test_compiler.py

@@ -3,6 +3,7 @@
 import subprocess
 import glob
 import difflib
+import warnings
 
 # Paths
 TESTS_ROOT_DIR = os.path.dirname(os.path.abspath(__file__))
@@ -118,7 +119,10 @@ def test_dana_program(compiler, dana_file):
                 diff_text = "\n".join(diff)
                 pytest.fail(f"Output mismatch for {base_name}:\n{diff_text}")
         else:
-            pytest.warns(None, match=f"No .result file for {base_name} — skipping output verification")
+            warnings.warn(
+                f"No .result file for {base_name} — skipping output verification",
+                UserWarning,
+            )
 
     finally:
         # Cleanup a.out