feat(gnovm): improved native bindings

gnovm/pkg/gnolang/go2gno.go

@@ -112,9 +112,9 @@ func ParseFile(filename string, body string) (fn *FileNode, err error) {
 	defer func() {
 		if r := recover(); r != nil {
 			if rerr, ok := r.(error); ok {
-				err = rerr
+				err = errors.Wrap(rerr, "parsing file")
 			} else {
-				err = errors.New(fmt.Sprintf("%v", r))
+				err = errors.New(fmt.Sprintf("%v", r)).Stacktrace()
 			}
 			return
 		}
@@ -431,7 +431,16 @@ func Go2Gno(fs *token.FileSet, gon ast.Node) (n Node) {
 		}
 		name := toName(gon.Name)
 		type_ := Go2Gno(fs, gon.Type).(*FuncTypeExpr)
-		body := Go2Gno(fs, gon.Body).(*BlockStmt).Body
+		var body []Stmt
+		if gon.Body != nil {
+			body = Go2Gno(fs, gon.Body).(*BlockStmt).Body
+		} else {
+			/*bd, err := ParseExpr(`panic("call to bodyless/external function is invalid outside of standard library")`)
+			if err != nil {
+				panic(err)
+			}
+			body = []Stmt{&ExprStmt{X: bd}}*/
+		}
 		return &FuncDecl{
 			IsMethod: isMethod,
 			Recv:     recv,

gnovm/pkg/gnolang/nodes.go

@@ -1369,6 +1369,14 @@ func (x *PackageNode) DefineNative(n Name, ps, rs FieldTypeExprs, native func(*M
 	if native == nil {
 		panic("DefineNative expects a function, but got nil")
 	}
+
+	if idx, exists := x.GetLocalIndex(n); exists {
+		// XXX(morgan): trick to look as a new definition to Define2;
+		// if we try to redefine an old value it looks like precompile
+		// is not cooperating well with us...
+		x.Names[idx] = "#uncallable_" + x.Names[idx]
+	}
+
 	fd := FuncD(n, ps, rs, nil)
 	fd = Preprocess(nil, x, fd).(*FuncDecl)
 	ft := evalStaticType(nil, x, &fd.Type).(*FuncType)
@@ -1648,7 +1656,6 @@ func (sb *StaticBlock) GetStaticTypeOfAt(store Store, path ValuePath) Type {
 			path.Depth -= 1
 		}
 	}
-	panic("should not happen")
 }
 
 // Implements BlockNode.

gnovm/stdlibs/context.go

@@ -18,3 +18,6 @@ type ExecContext struct {
 	OrigSendSpent *std.Coins // mutable
 	Banker        Banker
 }
+
+func (e ExecContext) GetTimestamp() int64     { return e.Timestamp }
+func (e ExecContext) GetTimestampNano() int64 { return e.TimestampNano }

gnovm/stdlibs/crypto/sha256/sha256.gno

@@ -1,12 +1,6 @@
 package sha256
 
-import (
-	isha256 "internal/crypto/sha256"
-)
-
 const Size = 32
 
 // Sum returns the SHA-256 checksum of the data.
-func Sum256(data []byte) [Size]byte {
-	return isha256.Sum256(data)
-}
+func Sum256(data []byte) [Size]byte

gnovm/stdlibs/crypto/sha256/sha256.go

@@ -0,0 +1,7 @@
+package sha256
+
+import "crypto/sha256"
+
+func Sum256(data []byte) [32]byte {
+	return sha256.Sum256(data)
+}