feat: add checkAssignmentMismatch

gnolang · Jun 2, 2024 · bd4b924 · bd4b924
1 parent b436f3a
commit bd4b924
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Showing 4 changed files with 20 additions and 12 deletions.
diff --git a/gnovm/pkg/gnolang/preprocess.go b/gnovm/pkg/gnolang/preprocess.go
@@ -1857,13 +1857,11 @@ func Preprocess(store Store, ctx BlockNode, n Node) Node {
 				tvs := make([]TypedValue, numNames)
 				if numNames > 1 && len(n.Values) == 1 {
 					// special case if `var a, b, c T? = f()` form.
-					cx, ok := n.Values[0].(*CallExpr)
-					if !ok {
-						panic("should not happen")
-					}
+					cx := n.Values[0].(*CallExpr)
 					tt := evalStaticTypeOfRaw(store, last, cx).(*tupleType)
-					if len(tt.Elts) != numNames {
-						panic("should not happen")
+					rLen := len(tt.Elts)
+					if rLen != numNames {
+						panic(fmt.Sprintf("assignment mismatch: %d variable(s) but %s returns %d value(s)", numNames, cx.Func.String(), rLen))
 					}
 					if n.Type != nil {
 						// only a single type can be specified.
@@ -2984,6 +2982,18 @@ func checkIntegerType(xt Type) {
 	}
 }
 
+func checkAssignmentMismatch(d Decl) {
+	if cd, ok := d.(*ValueDecl); ok {
+		numNames := len(cd.NameExprs)
+		numValues := len(cd.Values)
+		if numValues > 0 && numValues != numNames {
+			if _, ok := cd.Values[0].(*CallExpr); !ok {
+				panic(fmt.Sprintf("assignment mismatch: %d variable(s) but %d value(s)", numNames, numValues))
+			}
+		}
+	}
+}
+
 // predefineNow() pre-defines (with empty placeholders) all
 // declaration names, and then preprocesses all type/value decls, and
 // partially processes func decls.
@@ -3016,6 +3026,7 @@ func predefineNow(store Store, last BlockNode, d Decl) (Decl, bool) {
 			}
 		}
 	}()
+	checkAssignmentMismatch(d)
 	m := make(map[Name]struct{})
 	return predefineNow2(store, last, d, m)
 }

diff --git a/gnovm/tests/files/var18.gno b/gnovm/tests/files/var18.gno
@@ -5,7 +5,4 @@ func main() {
 }
 
 // Error:
-// main/files/var18.gno:3: should not happen:
-// --- preprocess stack ---
-// stack 0: func main() { var a<VPBlock(1,0)>, b<VPBlock(1,1)> = (const (1 <untyped> bigint)) }
-// ------------------------
+// main/files/var18.gno:3: assignment mismatch: 2 variable(s) but 1 value(s)
diff --git a/gnovm/tests/files/var19.gno b/gnovm/tests/files/var19.gno
@@ -8,4 +8,4 @@ func main() {
 }
 
 // Error:
-// main/files/var19.gno:3: constant definition loop with a
+// main/files/var19.gno:3: assignment mismatch: 3 variable(s) but 2 value(s)
diff --git a/gnovm/tests/files/var20.gno b/gnovm/tests/files/var20.gno
@@ -9,7 +9,7 @@ func main() {
 }
 
 // Error:
-// main/files/var20.gno:7: should not happen:
+// main/files/var20.gno:7: assignment mismatch: 3 variable(s) but r<VPBlock(3,0)> returns 1 value(s):
 // --- preprocess stack ---
 // stack 0: func main() { var a<VPBlock(1,0)>, b<VPBlock(1,1)>, c<VPBlock(1,2)> = r<VPBlock(3,0)>() }
 // ------------------------