feat: avoid Instantiation of banker on pure packages

gnovm/stdlibs/std/banker.gno

@@ -65,6 +65,7 @@ func (b BankerType) String() string {
 // GetBanker returns a new Banker, with its capabilities matching the given
 // [BankerType].
 func GetBanker(bt BankerType) Banker {
+	assertCallerIsRealm()
 	if bt >= maxBanker {
 		panic("invalid banker type")
 	}

gnovm/stdlibs/std/native.gno

@@ -65,3 +65,4 @@ func getRealm(height int) (address string, pkgPath string)
 func derivePkgAddr(pkgPath string) string
 func encodeBech32(prefix string, bz [20]byte) string
 func decodeBech32(addr string) (prefix string, bz [20]byte, ok bool)
+func assertCallerIsRealm()

gnovm/stdlibs/std/native.go

@@ -1,7 +1,8 @@
 package std
 
 import (
+	"github.com/gnolang/gno/gnovm/pkg/gnolang"
 	gno "github.com/gnolang/gno/gnovm/pkg/gnolang"
 	"github.com/gnolang/gno/tm2/pkg/bech32"
 	"github.com/gnolang/gno/tm2/pkg/crypto"
 	"github.com/gnolang/gno/tm2/pkg/std"
@@ -158,6 +159,13 @@
 	return prefix, [20]byte(bz), true
 }
 
+func X_assertCallerIsRealm(m *gno.Machine) {
+	frame := m.Frames[m.NumFrames()-2]
+	if path := frame.LastPackage.PkgPath; !gnolang.IsRealmPath(path) {
+		m.Panic(typedString("caller is not a realm"))
+	}
+}
+
 func typedString(s string) gno.TypedValue {
 	tv := gno.TypedValue{T: gno.StringType}
 	tv.SetString(gno.StringValue(s))

gnovm/tests/files/stdbanker_stdlibs.gno

@@ -0,0 +1,13 @@
+package main
+
+import "std"
+
+func main() {
+	defer func() {
+		println(recover())
+	}()
+	std.TestSetRealm(std.NewCodeRealm("gno.land/p/demo/users"))
+}
+
+// Output:
+// should only be called for Realms

gnovm/tests/stdlibs/std/frame_testing.gno

@@ -8,5 +8,8 @@ func NewUserRealm(user Address) Realm {
 // NewCodeRealm creates a new realm for a published code realm with the given
 // pkgPath.
 func NewCodeRealm(pkgPath string) Realm {
+	if !isRealm(pkgPath){
+		panic("should only be called for Realms")
+	}
 	return Realm{pkgPath: pkgPath, addr: DerivePkgAddr(pkgPath)}
 }

gnovm/tests/stdlibs/std/std.gno

@@ -38,3 +38,4 @@ func testSetOrigSend(
 	spentDenom []string, spentAmt []int64)
 func testIssueCoins(addr string, denom []string, amt []int64)
 func getRealm(height int) (address string, pkgPath string)
+func isRealm(pkgPath string) bool

gnovm/tests/stdlibs/std/std.go

@@ -173,6 +173,10 @@ func X_getRealm(m *gno.Machine, height int) (address string, pkgPath string) {
 	return string(ctx.OrigCaller), ""
 }
 
+func X_isRealm(m *gno.Machine, pkgPath string) bool {
+	return gno.IsRealmPath(pkgPath)
+}
+
 func X_testSetOrigSend(m *gno.Machine,
 	sentDenom []string, sentAmt []int64,
 	spentDenom []string, spentAmt []int64,