Improve clarity around GoIter creation; bump min Go version to 1.21

.circleci/config.yml

@@ -168,7 +168,7 @@ jobs:
 
   format-go:
     docker:
-      - image: cimg/go:1.19.7
+      - image: cimg/go:1.21.4
     steps:
       - run:
           name: Install gofumpt
@@ -186,7 +186,7 @@ jobs:
   # Build types and cosmwam package without cgo
   wasmvm_no_cgo:
     docker:
-      - image: cimg/go:1.19.7
+      - image: cimg/go:1.21.4
     steps:
       - checkout
       - run:
@@ -204,12 +204,12 @@ jobs:
 
   tidy-go:
     docker:
-      - image: cimg/go:1.19.7
+      - image: cimg/go:1.21.4
     steps:
       - checkout
       - run:
           name: Check go mod tidy
-          # Use --check or --exit-code when available (Go 1.19?)
+          # Use --check or --exit-code when available (Go 1.22?)
           # https://github.com/golang/go/issues/27005
           command: |
             go mod tidy
@@ -222,7 +222,7 @@ jobs:
 
   format-scripts:
     docker:
-      - image: cimg/go:1.21.3
+      - image: cimg/go:1.21.4
     steps:
       - run:
           name: Install shfmt
@@ -279,7 +279,7 @@ jobs:
   # Test the Go project
   wasmvm_test:
     docker:
-      - image: cimg/go:1.19.7
+      - image: cimg/go:1.21.4
     environment:
       GORACE: "halt_on_error=1"
       BUILD_VERSION: $(echo ${CIRCLE_SHA1} | cut -c 1-10)
@@ -458,7 +458,7 @@ workflows:
                 # long living branches
                 - main
                 # Development
-                - no-go-in-builder
+                - GoIter-creation
       # Run only on main, not on tags (auto-build on merge PR)
       - deploy_to_git:
           requires:

Makefile

@@ -63,7 +63,7 @@ test:
 
 test-safety:
 	# Use package list mode to include all subdirectores. The -count=1 turns off caching.
-	GODEBUG=cgocheck=2 go test -race -v -count=1 ./...
+	GOEXPERIMENT=cgocheck2 go test -race -v -count=1 ./...
 
 # Creates a release build in a containerized build environment of the static library for Alpine Linux (.a)
 release-build-alpine:

go.mod

@@ -1,6 +1,6 @@
 module github.com/CosmWasm/wasmvm
 
-go 1.18
+go 1.21
 
 require (
 	github.com/google/btree v1.0.0

internal/api/callbacks.go

@@ -263,8 +263,12 @@ func cScan(ptr *C.db_t, gasMeter *C.gas_meter_t, usedGas *cu64, start C.U8SliceV
 		return C.GoError_User
 	}
 
-	out.state = cIterator
-	out.vtable = iterator_vtable
+	*out = C.GoIter{
+		gas_meter: gasMeter,
+		state:     cIterator,
+		vtable:    iterator_vtable,
+	}
+
 	return C.GoError_None
 }
 

internal/api/lib.go

@@ -181,6 +181,9 @@ func Instantiate(
 	defer runtime.KeepAlive(info)
 	m := makeView(msg)
 	defer runtime.KeepAlive(msg)
+	var pinner runtime.Pinner
+	pinner.Pin(gasMeter)
+	defer pinner.Unpin()
 
 	callID := startCall()
 	defer endCall(callID)
@@ -221,6 +224,9 @@ func Execute(
 	defer runtime.KeepAlive(info)
 	m := makeView(msg)
 	defer runtime.KeepAlive(msg)
+	var pinner runtime.Pinner
+	pinner.Pin(gasMeter)
+	defer pinner.Unpin()
 
 	callID := startCall()
 	defer endCall(callID)
@@ -258,6 +264,9 @@ func Migrate(
 	defer runtime.KeepAlive(env)
 	m := makeView(msg)
 	defer runtime.KeepAlive(msg)
+	var pinner runtime.Pinner
+	pinner.Pin(gasMeter)
+	defer pinner.Unpin()
 
 	callID := startCall()
 	defer endCall(callID)
@@ -295,6 +304,9 @@ func Sudo(
 	defer runtime.KeepAlive(env)
 	m := makeView(msg)
 	defer runtime.KeepAlive(msg)
+	var pinner runtime.Pinner
+	pinner.Pin(gasMeter)
+	defer pinner.Unpin()
 
 	callID := startCall()
 	defer endCall(callID)
@@ -332,6 +344,9 @@ func Reply(
 	defer runtime.KeepAlive(env)
 	r := makeView(reply)
 	defer runtime.KeepAlive(reply)
+	var pinner runtime.Pinner
+	pinner.Pin(gasMeter)
+	defer pinner.Unpin()
 
 	callID := startCall()
 	defer endCall(callID)
@@ -369,6 +384,9 @@ func Query(
 	defer runtime.KeepAlive(env)
 	m := makeView(msg)
 	defer runtime.KeepAlive(msg)
+	var pinner runtime.Pinner
+	pinner.Pin(gasMeter)
+	defer pinner.Unpin()
 
 	callID := startCall()
 	defer endCall(callID)
@@ -406,6 +424,9 @@ func IBCChannelOpen(
 	defer runtime.KeepAlive(env)
 	m := makeView(msg)
 	defer runtime.KeepAlive(msg)
+	var pinner runtime.Pinner
+	pinner.Pin(gasMeter)
+	defer pinner.Unpin()
 
 	callID := startCall()
 	defer endCall(callID)
@@ -443,6 +464,9 @@ func IBCChannelConnect(
 	defer runtime.KeepAlive(env)
 	m := makeView(msg)
 	defer runtime.KeepAlive(msg)
+	var pinner runtime.Pinner
+	pinner.Pin(gasMeter)
+	defer pinner.Unpin()
 
 	callID := startCall()
 	defer endCall(callID)
@@ -480,6 +504,9 @@ func IBCChannelClose(
 	defer runtime.KeepAlive(env)
 	m := makeView(msg)
 	defer runtime.KeepAlive(msg)
+	var pinner runtime.Pinner
+	pinner.Pin(gasMeter)
+	defer pinner.Unpin()
 
 	callID := startCall()
 	defer endCall(callID)
@@ -517,6 +544,9 @@ func IBCPacketReceive(
 	defer runtime.KeepAlive(env)
 	pa := makeView(packet)
 	defer runtime.KeepAlive(packet)
+	var pinner runtime.Pinner
+	pinner.Pin(gasMeter)
+	defer pinner.Unpin()
 
 	callID := startCall()
 	defer endCall(callID)
@@ -554,6 +584,9 @@ func IBCPacketAck(
 	defer runtime.KeepAlive(env)
 	ac := makeView(ack)
 	defer runtime.KeepAlive(ack)
+	var pinner runtime.Pinner
+	pinner.Pin(gasMeter)
+	defer pinner.Unpin()
 
 	callID := startCall()
 	defer endCall(callID)
@@ -591,6 +624,9 @@ func IBCPacketTimeout(
 	defer runtime.KeepAlive(env)
 	pa := makeView(packet)
 	defer runtime.KeepAlive(packet)
+	var pinner runtime.Pinner
+	pinner.Pin(gasMeter)
+	defer pinner.Unpin()
 
 	callID := startCall()
 	defer endCall(callID)

libwasmvm/src/iterator.rs

@@ -60,9 +60,14 @@ pub struct GoIter {
 }
 
 impl GoIter {
-    pub fn new(gas_meter: *mut gas_meter_t) -> Self {
+    /// Creates an incomplete GoIter with unset fields.
+    /// This is not ready to be used until those fields are set.
+    ///
+    /// This is needed to create a correct instance in Rust
+    /// which is then filled in Go (see `fn scan`).
+    pub fn stub() -> Self {
         GoIter {
-            gas_meter,
+            gas_meter: std::ptr::null_mut(),
             state: iterator_t::default(),
             vtable: IteratorVtable::default(),
         }
@@ -170,3 +175,25 @@ impl GoIter {
         (Ok(output), gas_info)
     }
 }
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn goiter_stub_works() {
+        // can be created and dropped
+        {
+            let _iter = GoIter::stub();
+        }
+
+        // creates an all null-instance
+        let iter = GoIter::stub();
+        assert!(iter.gas_meter.is_null());
+        assert_eq!(iter.state.call_id, 0);
+        assert_eq!(iter.state.iterator_index, 0);
+        assert!(iter.vtable.next.is_none());
+        assert!(iter.vtable.next_key.is_none());
+        assert!(iter.vtable.next_value.is_none());
+    }
+}

libwasmvm/src/storage.rs

@@ -70,7 +70,7 @@ impl Storage for GoStorage {
         order: Order,
     ) -> BackendResult<u32> {
         let mut error_msg = UnmanagedVector::default();
-        let mut iter = GoIter::new(self.db.gas_meter);
+        let mut iter = GoIter::stub();
         let mut used_gas = 0_u64;
         let scan_db = self
             .db