compile: symtable: global and nonlocal

Author: ncw

compile/make_symtable_test.py

@@ -22,6 +22,26 @@ def fn(a:"a",*arg:"arg",b:"b"=1,c:"c"=2,**kwargs:"kw") -> "ret":
     def fn(A,b):
         e=1
         return a*arg*b*c*kwargs*A*e*glob''', "exec"),
+    ('''\
+def fn(a):
+    global b
+    b = a''', "exec"),
+    ('''\
+def fn(a):
+    b = 6
+    global b
+    b = a''', "exec"),
+    ('''\
+def outer():
+   x = 1
+   def inner():
+       nonlocal x
+       x = 2''', "exec"),
+    ('''\
+def outer():
+   def inner():
+       nonlocal x
+       x = 2''', "exec", SyntaxError),
     # FIXME need with x as y
 ]
 
@@ -149,14 +169,15 @@ def main():
                 error = e.msg
             else:
                 raise ValueError("Expecting exception %s" % exc)
-            table = "nil"
+            dumped_symtable = "nil"
             gostring = "nil"
             exc_name = "py.%s" % exc.__name__
         else:
             table = symtable(source, "<string>", mode)
             exc_name = "nil"
             error = ""
-        out.append('{"%s", "%s", %s, %s, "%s"},' % (escape(source), mode, dump_symtable(table), exc_name, escape(error)))
+            dumped_symtable = dump_symtable(table)
+        out.append('{"%s", "%s", %s, %s, "%s"},' % (escape(source), mode, dumped_symtable, exc_name, escape(error)))
     out.append("}\n")
     print("Writing %s" % path)
     with open(path, "w") as f:

compile/symtable.go

@@ -10,6 +10,7 @@
 package compile
 
 import (
+	"log"
 	"strings"
 
 	"github.com/ncw/gpython/ast"
@@ -153,10 +154,34 @@ func (st *SymTable) Parse(Ast ast.Ast) {
 		switch node := Ast.(type) {
 		case *ast.Nonlocal:
 			for _, name := range node.Names {
+				cur, ok := st.Symbols[string(name)]
+				if ok {
+					if (cur.Flags & defLocal) != 0 {
+						// FIXME this should be a warning
+						log.Printf("name '%s' is assigned to before nonlocal declaration", name)
+
+					}
+					if (cur.Flags & defUse) != 0 {
+						// FIXME this should be a warning
+						log.Printf("name '%s' is used prior to nonlocal declaration", name)
+					}
+				}
 				st.AddDef(name, defNonlocal)
 			}
 		case *ast.Global:
 			for _, name := range node.Names {
+				cur, ok := st.Symbols[string(name)]
+				if ok {
+					if (cur.Flags & defLocal) != 0 {
+						// FIXME this should be a warning
+						log.Printf("name '%s' is assigned to before global declaration", name)
+
+					}
+					if (cur.Flags & defUse) != 0 {
+						// FIXME this should be a warning
+						log.Printf("name '%s' is used prior to global declaration", name)
+					}
+				}
 				st.AddDef(name, defGlobal)
 			}
 		case *ast.Name:
@@ -449,7 +474,7 @@ func (st *SymTable) AnalyzeName(scopes Scopes, name string, flags DefUse, bound,
 		if bound == nil {
 			panic(py.ExceptionNewf(py.SyntaxError, "nonlocal declaration not allowed at module level"))
 		}
-		if bound.Contains(name) {
+		if !bound.Contains(name) {
 			panic(py.ExceptionNewf(py.SyntaxError, "no binding for nonlocal '%s' found", name))
 		}
 		scopes[name] = scopeFree