fix: dont allow calling init

_test/init1.go

@@ -0,0 +1,12 @@
+package main
+
+func init() {
+	println("here")
+}
+
+func main() {
+	init()
+}
+
+// Error:
+// _test/init1.go:8:2: undefined: init

interp/cfg.go

@@ -1153,11 +1153,11 @@ func (interp *Interpreter) cfg(root *node, pkgID string) ([]*node, error) {
 			n.types = sc.types
 			sc = sc.pop()
 			funcName := n.child[1].ident
-			if !isMethod(n) {
-				interp.scopes[pkgID].sym[funcName].index = -1 // to force value to n.val
-				interp.scopes[pkgID].sym[funcName].typ = n.typ
-				interp.scopes[pkgID].sym[funcName].kind = funcSym
-				interp.scopes[pkgID].sym[funcName].node = n
+			if sym := sc.sym[funcName]; !isMethod(n) && sym != nil {
+				sym.index = -1 // to force value to n.val
+				sym.typ = n.typ
+				sym.kind = funcSym
+				sym.node = n
 			}
 
 		case funcLit:
@@ -1172,6 +1172,10 @@ func (interp *Interpreter) cfg(root *node, pkgID string) ([]*node, error) {
 			if isKey(n) || isNewDefine(n, sc) {
 				break
 			}
+			if n.anc.kind == funcDecl && n.anc.child[1] == n {
+				// Dont process a function name identExpr.
+				break
+			}
 
 			sym, level, found := sc.lookup(n.ident)
 			if !found {

interp/gta.go

@@ -138,11 +138,13 @@ func (interp *Interpreter) gta(root *node, rpath, pkgID string) ([]*node, error)
 			if n.typ, err = nodeType(interp, sc, n.child[2]); err != nil {
 				return false
 			}
-			if isMethod(n) {
+			ident := n.child[1].ident
+			switch {
+			case isMethod(n):
 				// TODO(mpl): redeclaration detection
 				// Add a method symbol in the receiver type name space
 				var rcvrtype *itype
-				n.ident = n.child[1].ident
+				n.ident = ident
 				rcvr := n.child[0].child[0]
 				rtn := rcvr.lastChild()
 				typeName := rtn.ident
@@ -167,33 +169,32 @@ func (interp *Interpreter) gta(root *node, rpath, pkgID string) ([]*node, error)
 				}
 				rcvrtype.method = append(rcvrtype.method, n)
 				n.child[0].child[0].lastChild().typ = rcvrtype
-			} else {
-				ident := n.child[1].ident
+			case ident == "init":
 				// TODO(mpl): use constant instead of hardcoded string?
-				if ident != "init" {
-					asImportName := filepath.Join(ident, baseName)
-					if _, exists := sc.sym[asImportName]; exists {
-						// redeclaration error
-						// TODO(mpl): improve error with position of previous declaration.
-						err = n.cfgErrorf("%s redeclared in this block", ident)
-						return false
-					}
-					sym, exists := sc.sym[ident]
-					if exists {
-						// Make sure the symbol we found seems to be about another node, before calling
-						// it a redeclaration.
-						if sym.typ.isComplete() {
-							// TODO(mpl): this check might be too permissive?
-							if sym.kind != funcSym || sym.typ.cat != n.typ.cat || sym.node != n || sym.index != -1 {
-								// redeclaration error
-								// TODO(mpl): improve error with position of previous declaration.
-								err = n.cfgErrorf("%s redeclared in this block", ident)
-								return false
-							}
+				// init functions do not get declared as per the Go spec.
+			default:
+				asImportName := filepath.Join(ident, baseName)
+				if _, exists := sc.sym[asImportName]; exists {
+					// redeclaration error
+					// TODO(mpl): improve error with position of previous declaration.
+					err = n.cfgErrorf("%s redeclared in this block", ident)
+					return false
+				}
+				sym, exists := sc.sym[ident]
+				if exists {
+					// Make sure the symbol we found seems to be about another node, before calling
+					// it a redeclaration.
+					if sym.typ.isComplete() {
+						// TODO(mpl): this check might be too permissive?
+						if sym.kind != funcSym || sym.typ.cat != n.typ.cat || sym.node != n || sym.index != -1 {
+							// redeclaration error
+							// TODO(mpl): improve error with position of previous declaration.
+							err = n.cfgErrorf("%s redeclared in this block", ident)
+							return false
 						}
 					}
 				}
-				// Add a function symbol in the package name space
+				// Add a function symbol in the package name space except for init
 				sc.sym[n.child[1].ident] = &symbol{kind: funcSym, typ: n.typ, node: n, index: -1}
 			}
 			if !n.typ.isComplete() {

interp/interp_consistent_test.go

@@ -45,6 +45,7 @@ func TestInterpConsistencyBuild(t *testing.T) {
 			file.Name() == "fun22.go" || // expect error
 			file.Name() == "if2.go" || // expect error
 			file.Name() == "import6.go" || // expect error
+			file.Name() == "init1.go" || // expect error
 			file.Name() == "io0.go" || // use random number
 			file.Name() == "op1.go" || // expect error
 			file.Name() == "op7.go" || // expect error