WIP fix(gnovm): correct const type deduction

gnovm/pkg/gnolang/gno_test.go

@@ -179,7 +179,7 @@ func BenchmarkIfStatement(b *testing.B) {
 func main() {
 	for i:=0; i<10000; i++ {
 		if i > 10 {
-			
+
 		}
 	}
 }`

gnovm/pkg/gnolang/go2gno.go

@@ -132,6 +132,7 @@ func ParseFile(filename string, body string) (fn *FileNode, err error) {
 	}()
 	// parse with Go2Gno.
 	fn = Go2Gno(fs, f).(*FileNode)
+	//fmt.Println("---fn after transpile: ", fn)
 	fn.Name = Name(filename)
 	return fn, nil
 }
@@ -408,6 +409,7 @@ func Go2Gno(fs *token.FileSet, gon ast.Node) (n Node) {
 				VarName:      toName(as.Lhs[0].(*ast.Ident)),
 			}
 		case *ast.ExprStmt:
+			println("---ExprStmt")
 			return &SwitchStmt{
 				Init:         toStmt(fs, gon.Init),
 				X:            toExpr(fs, as.X.(*ast.TypeAssertExpr).X),
@@ -457,6 +459,7 @@ func Go2Gno(fs *token.FileSet, gon ast.Node) (n Node) {
 	case *ast.GenDecl:
 		panic("unexpected *ast.GenDecl; use toDecls(fs,) instead")
 	case *ast.File:
+		//println("---ast.File")
 		pkgName := Name(gon.Name.Name)
 		decls := make([]Decl, 0, len(gon.Decls))
 		for _, d := range gon.Decls {
@@ -767,14 +770,22 @@ func toDecls(fs *token.FileSet, gd *ast.GenDecl) (ds Decls) {
 				for _, id := range s.Names {
 					names = append(names, *Nx(toName(id)))
 				}
-				if s.Type == nil {
+				if s.Type == nil && s.Values == nil { // inherit declared type
 					tipe = lastType
 				} else {
-					tipe = toExpr(fs, s.Type)
-					lastType = tipe
+					lastType = toExpr(fs, s.Type)
 				}
+
+				if nx, ok := lastType.(*NameExpr); ok {
+					if !isPrimitiveType(string(nx.Name)) {
+						tipe = lastType
+					}
+				}
+
 				if s.Values == nil {
+					// inherit type from last values
 					values = copyExprs(lastValues)
+					// if lastType is declaredType, inherit it
 				} else {
 					values = toExprs(fs, s.Values)
 					lastValues = values
@@ -919,3 +930,19 @@ func toSwitchClauseStmt(fs *token.FileSet, cc *ast.CaseClause) SwitchClauseStmt
 		Body:  toStmts(fs, cc.Body),
 	}
 }
+func isPrimitiveType(typeStr string) bool {
+	// List of primitive type prefixes
+	primitiveTypes := []string{
+		"int", "int8", "int16", "int32", "int64",
+		"uint", "uint8", "uint16", "uint32", "uint64",
+		"float32", "float64", "string", "bool",
+	}
+
+	for _, t := range primitiveTypes {
+		if strings.HasPrefix(typeStr, t) {
+			return true
+		}
+	}
+
+	return false
+}

gnovm/pkg/gnolang/preprocess.go

@@ -2233,7 +2233,7 @@ func Preprocess(store Store, ctx BlockNode, n Node) Node {
 							}
 						}
 					}
-					// evaluate types and convert consts.
+
 					if n.Type != nil {
 						// only a single type can be specified.
 						nt := evalStaticType(store, last, n.Type)
@@ -2245,12 +2245,14 @@ func Preprocess(store Store, ctx BlockNode, n Node) Node {
 							checkOrConvertType(store, last, &n.Values[i], nt, false)
 						}
 					} else if n.Const {
-						// derive static type from values.
-						for i, vx := range n.Values {
-							vt := evalStaticTypeOf(store, last, vx)
-							sts[i] = vt
+						if n.Values != nil {
+							// derive static type from values.
+							for i, vx := range n.Values {
+								vt := evalStaticTypeOf(store, last, vx)
+								sts[i] = vt
+							}
 						}
-					} else {
+					} else { // not const, type is nil
 						// convert n.Value to default type.
 						for i, vx := range n.Values {
 							convertIfConst(store, last, vx)

gnovm/tests/files/const23.gno

@@ -0,0 +1,43 @@
+package main
+
+type Integer int
+
+const (
+	i0 Integer = 0
+
+	i int32 = 1
+	s       = "world"
+	c       = 1 << iota
+
+	s2   = "hey"
+	d, e = 1, "hello"
+
+	m, n
+
+	b    = 1 + 1
+	u    = +1
+	x, y = i0, "hello"
+)
+
+func main() {
+	println(i)
+	println(s)
+	println(c)
+	println(s2)
+	println(d, e)
+	println(m, n)
+	println(b)
+	println(u)
+	println(x, y)
+}
+
+// Output:
+// 1
+// world
+// 8
+// hey
+// 1 hello
+// 1 hello
+// 2
+// 1
+// (0 main.Integer) hello

gnovm/tests/files/const24.gno

@@ -0,0 +1,14 @@
+package main
+
+const (
+	s int = 1
+	g     = "world"
+	c     = 1 << iota
+)
+
+func main() {
+	println(c)
+}
+
+// Output:
+// 4

gnovm/tests/files/const25.gno

@@ -0,0 +1,14 @@
+package main
+
+const (
+	d, e = 1, "hello"
+	m
+)
+
+func main() {
+	println(d, e)
+	println(m)
+}
+
+// Error:
+// main/files/const25.gno:5:2: assignment mismatch: 1 variable(s) but 2 value(s)

gnovm/tests/files/const25a.gno

@@ -0,0 +1,14 @@
+package main
+
+const (
+	d, e = 1, "hello"
+	m, n, l
+)
+
+func main() {
+	println(d, e)
+	println(m)
+}
+
+// Error:
+// main/files/const25a.gno:5:2: assignment mismatch: 3 variable(s) but 2 value(s)

gnovm/tests/files/const26.gno

@@ -0,0 +1,15 @@
+package main
+
+const (
+	d = "hello"
+	m
+)
+
+func main() {
+	println(d)
+	println(m)
+}
+
+// Output:
+// hello
+// hello