Improve creation of local vars. Change handling package state and metadata (in progress)

_test/provider/foo.go

@@ -5,3 +5,7 @@ import "fmt"
 func Foo() {
 	fmt.Println("Hello from Foo")
 }
+
+func F1() {
+	fmt.Println("SomeString:", SomeString)
+}

_test/provider/provider.go

@@ -2,6 +2,10 @@ package provider
 
 import "fmt"
 
+const (
+	SomeString = "constant string"
+)
+
 type T1 struct {
 	Name string
 }

_test/src4.go

@@ -0,0 +1,10 @@
+package main
+
+import "github.com/containous/gi/_test/provider"
+
+func main() {
+	provider.F1()
+}
+
+// Output:
+// Hello from Foo

interp/ast.go

@@ -262,13 +262,8 @@ func (a Action) String() string {
 
 // Ast parses src string containing Go code and generates the corresponding AST.
 // The AST root node is returned.
-func (interp *Interpreter) Ast(src string, pre *NodeMap) (*Node, *NodeMap) {
-	var def NodeMap
-	if pre == nil {
-		def = make(map[string]*Node)
-	} else {
-		def = *pre
-	}
+func (interp *Interpreter) Ast(src string) (*Node, *NodeMap) {
+	def := NodeMap{}
 	fset := token.NewFileSet() // positions are relative to fset
 	f, err := parser.ParseFile(fset, "sample.go", src, 0)
 	if err != nil {
@@ -280,6 +275,7 @@ func (interp *Interpreter) Ast(src string, pre *NodeMap) (*Node, *NodeMap) {
 	var st nodestack
 	var nbAssign int
 	var typeSpec bool
+	var pkgName string
 
 	addChild := func(root **Node, anc *Node, index *int, kind Kind, action Action) *Node {
 		*index++
@@ -467,6 +463,7 @@ func (interp *Interpreter) Ast(src string, pre *NodeMap) (*Node, *NodeMap) {
 			st.push(addChild(&root, anc, &index, FieldList, Nop))
 
 		case *ast.File:
+			pkgName = a.Name.Name
 			st.push(addChild(&root, anc, &index, File, Nop))
 
 		case *ast.ForStmt:

interp/cfg.go

@@ -41,12 +41,18 @@ func (s *Scope) lookup(ident string) (*Symbol, int, bool) {
 	return nil, 0, false
 }
 
-// FrameIndex type defines metadata for Tracking frame index for variables in function context
+// FrameIndex type stores informations to allocate frame space for variables
 type FrameIndex struct {
 	anc *FrameIndex // Ancestor upper frame
 	max int         // The highest index in frame
 }
 
+// PkgContext type stores current state of a package during compiling
+type PkgContext struct {
+	frameIndex *FrameIndex
+	nodeMap    *NodeMap
+}
+
 // Cfg generates a control flow graph (CFG) from AST (wiring successors in AST)
 // and pre-compute frame sizes and indexes for all un-named (temporary) and named
 // variables. A list of nodes of init functions is returned.
@@ -66,6 +72,7 @@ func (interp *Interpreter) Cfg(root *Node, sdef *NodeMap) []*Node {
 	for name, node := range *sdef {
 		scope.sym[name] = &Symbol{node: node, index: -1}
 	}
+	log.Println(interp.srcPkg["provider"])
 
 	root.Walk(func(n *Node) bool {
 		// Pre-order processing
@@ -600,6 +607,8 @@ func (interp *Interpreter) Cfg(root *Node, sdef *NodeMap) []*Node {
 		case Ident:
 			if n.anc.kind == File || (n.anc.kind == SelectorExpr && n.anc.child[0] != n) {
 				// skip symbol creation/lookup for idents used as key
+			} else if n.ident == "nil" {
+				n.kind = BasicLit
 			} else if n.ident == "false" {
 				n.val = false
 				n.typ = defaultTypes["bool"]
@@ -630,10 +639,28 @@ func (interp *Interpreter) Cfg(root *Node, sdef *NodeMap) []*Node {
 				n.kind = node.kind
 				n.findex = node.findex
 			} else {
-				//log.Println(n.index, n.ident, n.anc.kind, "unresolved, create new")
-				frameIndex.max++
-				scope.sym[n.ident] = &Symbol{index: frameIndex.max}
-				n.findex = frameIndex.max
+				if n.ident == "_" || n.anc.kind == Define || n.anc.kind == DefineX || n.anc.kind == Field || n.anc.kind == RangeStmt || n.anc.kind == ValueSpec {
+					// Create a new local symbol for func argument or local var definition
+					frameIndex.max++
+					scope.sym[n.ident] = &Symbol{index: frameIndex.max}
+					n.findex = frameIndex.max
+				} else {
+					// symbol may be defined globally elsewhere later, add an entry at pkg level
+					symFrameIndex := frameIndex
+					symScope := scope
+					level := 0
+					for symFrameIndex.anc != nil {
+						level++
+						symScope = symScope.anc
+						symFrameIndex = symFrameIndex.anc
+					}
+					symFrameIndex.max++
+					symScope.sym[n.ident] = &Symbol{index: symFrameIndex.max}
+					(*sdef)[n.ident] = n
+					n.findex = symFrameIndex.max
+					n.level = level
+					log.Println(n.index, n.ident, n.anc.kind, "unresolved, create new at pkg level", n.findex, level)
+				}
 			}
 
 		case If0: // if cond {}
@@ -869,6 +896,7 @@ func (interp *Interpreter) Cfg(root *Node, sdef *NodeMap) []*Node {
 			}
 		}
 	})
+	log.Println(sdef)
 	return initNodes
 }
 

interp/interp.go

@@ -118,7 +118,7 @@ func (i *Interpreter) ImportBin(pkg *map[string]*map[string]interface{}) {
 // current interpreted package exported symbols
 func (i *Interpreter) Eval(src string) (string, *NodeMap) {
 	// Parse source to AST
-	root, sdef := i.Ast(src, nil)
+	root, sdef := i.Ast(src)
 	if i.AstDot {
 		root.AstDot(DotX())
 	}

interp/run.go

@@ -2,6 +2,7 @@ package interp
 
 import (
 	"fmt"
+	"log"
 	"reflect"
 	"time"
 )
@@ -127,7 +128,7 @@ func value(n *Node, f *Frame) interface{} {
 	case Rvalue:
 		return n.rval
 	default:
-		//log.Println(n.index, n.findex, n.level, f)
+		//log.Println(n.index, n.ident, n.findex, n.level, f)
 		for level := n.level; level > 0; level-- {
 			f = f.anc
 		}
@@ -139,6 +140,7 @@ func value(n *Node, f *Frame) interface{} {
 }
 
 func addrValue(n *Node, f *Frame) *interface{} {
+	log.Println(n.index, n.ident, n.kind, n.level, n.findex)
 	switch n.kind {
 	case BasicLit, FuncDecl, Rvalue:
 		return &n.val
@@ -392,6 +394,7 @@ func callBin(n *Node, f *Frame) {
 		}
 	}
 	fun := value(n.child[0], f).(reflect.Value)
+	log.Println("in:", in)
 	v := fun.Call(in)
 	for i := 0; i < n.fsize; i++ {
 		f.data[n.findex+i] = v[i].Interface()
@@ -717,6 +720,7 @@ func slice(n *Node, f *Frame) {
 
 // slice expression, no low value
 func slice0(n *Node, f *Frame) {
+	log.Println(n.index, n.child[0].ident, value(n.child[0], f))
 	a := value(n.child[0], f).([]interface{})
 	switch len(n.child) {
 	case 1: