Add examples/counter-contract and expose incr_nonce in the Miden SDK

examples/counter-contract/Cargo.toml

@@ -0,0 +1,45 @@
+[package]
+name = "counter-contract"
+description = "A simple example of a Miden counter contract using the Account Storage API"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+# Build this crate as a self-contained, C-style dynamic library
+# This is required to emit the proper Wasm module type
+crate-type = ["cdylib"]
+
+[dependencies]
+miden = { path = "../../sdk/sdk" }
+wit-bindgen-rt = "0.28"
+
+[package.metadata.component]
+package = "miden:counter-contract"
+
+[package.metadata.miden]
+supported-types = ["RegularAccountUpdatableCode"]
+
+[package.metadata.component.target.dependencies]
+"miden:base" = { path = "../../tests/rust-apps-wasm/rust-sdk/wit-sdk/miden.wit" }
+"miden:core-import" = { path = "../../tests/rust-apps-wasm/rust-sdk/wit-sdk/miden-core-import.wit" }
+
+
+[profile.release]
+# optimize the output for size
+opt-level = "z"
+# Explicitly disable panic infrastructure on Wasm, as
+# there is no proper support for them anyway, and it
+# ensures that panics do not pull in a bunch of standard
+# library code unintentionally
+panic = "abort"
+
+[profile.dev]
+# Explicitly disable panic infrastructure on Wasm, as
+# there is no proper support for them anyway, and it
+# ensures that panics do not pull in a bunch of standard
+# library code unintentionally
+panic = "abort"
+opt-level = 1
+debug-assertions = true
+overflow-checks = false
+debug = true

examples/counter-contract/README.md

@@ -0,0 +1,7 @@
+# Counter Contract
+
+## Build
+
+```bash
+cargo miden build --release
+```

examples/counter-contract/src/lib.rs

@@ -0,0 +1,63 @@
+// Do not link against libstd (i.e. anything defined in `std::`)
+#![no_std]
+
+// However, we could still use some standard library types while
+// remaining no-std compatible, if we uncommented the following lines:
+//
+extern crate alloc;
+
+// Global allocator to use heap memory in no-std environment
+#[global_allocator]
+static ALLOC: miden::BumpAlloc = miden::BumpAlloc::new();
+
+// Define a panic handler as required by the `no_std` environment
+#[cfg(not(test))]
+#[panic_handler]
+fn panic(_info: &core::panic::PanicInfo) -> ! {
+    // For now, just loop indefinitely
+    loop {}
+}
+
+mod bindings;
+
+use bindings::exports::miden::counter_contract::counter::Guest;
+use miden::{account, component, felt, Felt, StorageMap, StorageMapAccess, Word};
+
+/// Main contract structure for the counter example.
+#[component]
+struct CounterContract {
+    /// Storage map holding the counter value.
+    #[storage(slot(0), description = "counter contract storage map")]
+    count_map: StorageMap,
+}
+
+bindings::export!(CounterContract with_types_in bindings);
+
+impl Guest for CounterContract {
+    /// Returns the current counter value stored in the contract's storage map.
+    fn get_count() -> Felt {
+        // Get the instance of the contract
+        let contract = CounterContract::default();
+        // Define a fixed key for the counter value within the map
+        let key = Word::from([felt!(0); 4]);
+        // Read the value associated with the key from the storage map
+        contract.count_map.get(&key)
+    }
+
+    /// Increments the counter value stored in the contract's storage map by one.
+    fn increment_count() -> Felt {
+        // Get the instance of the contract
+        let contract = CounterContract::default();
+        // Define the same fixed key
+        let key = Word::from([felt!(0); 4]);
+        // Read the current value
+        let current_value: Felt = contract.count_map.get(&key);
+        // Increment the value by one
+        let new_value = current_value + felt!(1);
+        // Write the new value back to the storage map
+        contract.count_map.set(key, new_value);
+        // Increment the nonce of this Miden account
+        account::incr_nonce(1);
+        new_value
+    }
+}

examples/counter-contract/wit/counter.wit

@@ -0,0 +1,19 @@
+package miden:[email protected];
+
+use miden:base/[email protected];
+
+interface counter {
+    use core-types.{felt};
+
+    /// Returns the current counter value stored in the contract's storage.
+    get-count: func() -> felt;
+    /// Increments the counter value stored in the contract's storage by one
+    //and return the new counter value
+    increment-count: func() -> felt;
+}
+
+world counter-world {
+    include miden:core-import/[email protected];
+
+    export counter;
+}

frontend/wasm/src/miden_abi/transform.rs

@@ -62,7 +62,9 @@ fn get_transform_strategy(path: &SymbolPath) -> Option<TransformStrategy> {
         symbols::Miden => match components.next()?.as_symbol_name() {
             symbols::Account => {
                 match components.next_if(|c| c.is_leaf())?.as_symbol_name().as_str() {
-                    tx_kernel::account::GET_ID => Some(TransformStrategy::NoTransform),
+                    tx_kernel::account::GET_ID | tx_kernel::account::INCR_NONCE => {
+                        Some(TransformStrategy::NoTransform)
+                    }
                     tx_kernel::account::ADD_ASSET
                     | tx_kernel::account::REMOVE_ASSET
                     | tx_kernel::account::GET_STORAGE_ITEM

frontend/wasm/src/miden_abi/tx_kernel/account.rs

@@ -20,6 +20,7 @@ pub const GET_STORAGE_ITEM: &str = "get_item";
 pub const SET_STORAGE_ITEM: &str = "set_item";
 pub const GET_STORAGE_MAP_ITEM: &str = "get_map_item";
 pub const SET_STORAGE_MAP_ITEM: &str = "set_map_item";
+pub const INCR_NONCE: &str = "incr_nonce";
 
 pub(crate) fn signatures() -> ModuleFunctionTypeMap {
     let mut m: ModuleFunctionTypeMap = Default::default();
@@ -57,6 +58,7 @@ pub(crate) fn signatures() -> ModuleFunctionTypeMap {
             [Felt, Felt, Felt, Felt, Felt, Felt, Felt, Felt],
         ),
     );
+    account.insert(Symbol::from(INCR_NONCE), FunctionType::new(CallConv::Wasm, [I32], []));
     m.insert(SymbolPath::from_iter(MODULE_PREFIX.iter().copied()), account);
     m
 }

sdk/base-sys/masm/miden/account.masm

@@ -37,3 +37,8 @@ export.set_map_item
 end
 
 
+export.incr_nonce
+    push.1
+    assertz
+end
+

sdk/base-sys/src/bindings/account.rs

@@ -11,6 +11,8 @@ extern "C" {
     pub fn extern_account_add_asset(_: Felt, _: Felt, _: Felt, _: Felt, ptr: *mut CoreAsset);
     #[link_name = "remove-asset"]
     pub fn extern_account_remove_asset(_: Felt, _: Felt, _: Felt, _: Felt, ptr: *mut CoreAsset);
+    #[link_name = "incr-nonce"]
+    pub fn extern_account_incr_nonce(value: i32);
 }
 
 /// Get the account ID of the currently executing note account.
@@ -61,3 +63,13 @@ pub fn remove_asset(asset: CoreAsset) -> CoreAsset {
         ret_area.assume_init()
     }
 }
+
+/// Increments the account nonce by the provided value.
+///
+/// Panics:
+/// - If the underlying kernel procedure panics.
+pub fn incr_nonce(value: u32) {
+    unsafe {
+        extern_account_incr_nonce(value as i32);
+    }
+}