bug: fix code being shifted when loaded via LDC (#1503)

e2e/Forc.toml

@@ -6,12 +6,12 @@ members = [
   'sway/bindings/simple_contract',
   'sway/bindings/type_paths',
   'sway/contracts/asserts',
-  'sway/contracts/huge_contract',
   'sway/contracts/auth_testing_abi',
   'sway/contracts/auth_testing_contract',
   'sway/contracts/block_timestamp',
   'sway/contracts/configurables',
   'sway/contracts/contract_test',
+  'sway/contracts/huge_contract',
   'sway/contracts/large_return_data',
   'sway/contracts/lib_contract',
   'sway/contracts/lib_contract_abi',
@@ -23,6 +23,7 @@ members = [
   'sway/contracts/multiple_read_calls',
   'sway/contracts/needs_custom_decoder',
   'sway/contracts/payable_annotation',
+  'sway/contracts/proxy',
   'sway/contracts/require',
   'sway/contracts/revert_transaction_error',
   'sway/contracts/storage',

e2e/build.rs

@@ -45,7 +45,12 @@ impl Downloader {
         const LINK_TEMPLATE: &str = "https://github.com/FuelLabs/fuel-core/releases/download/vVERSION/fuel-core-VERSION-x86_64-unknown-linux-gnu.tar.gz";
         let link = LINK_TEMPLATE.replace("VERSION", &SUPPORTED_FUEL_CORE_VERSION.to_string());
 
-        let response = reqwest::blocking::get(link)?;
+        let response = reqwest::blocking::Client::builder()
+            .timeout(std::time::Duration::from_secs(60))
+            .build()?
+            .get(link)
+            .send()?;
+
         if !response.status().is_success() {
             anyhow::bail!("Failed to download wasm executor: {}", response.status());
         }

e2e/sway/contracts/proxy/Forc.toml

@@ -0,0 +1,7 @@
+[project]
+authors = ["Fuel Labs <contact@fuel.sh>"]
+entry = "main.sw"
+license = "Apache-2.0"
+name = "proxy"
+
+[dependencies]

e2e/sway/contracts/proxy/src/main.sw

@@ -0,0 +1,29 @@
+contract;
+
+use std::execution::run_external;
+
+abi Proxy {
+    #[storage(write)]
+    fn set_target_contract(id: ContractId);
+
+    // this targets the method of the `huge_contract` in our e2e sway contracts
+    #[storage(read)]
+    fn something() -> u64;
+}
+
+storage {
+    target_contract: Option<ContractId> = None,
+}
+
+impl Proxy for Contract {
+    #[storage(write)]
+    fn set_target_contract(id: ContractId) {
+        storage.target_contract.write(Some(id));
+    }
+
+    #[storage(read)]
+    fn something() -> u64 {
+        let target = storage.target_contract.read().unwrap();
+        run_external(target)
+    }
+}

e2e/tests/contracts.rs

@@ -2309,3 +2309,53 @@ async fn loader_blob_already_uploaded_not_an_issue() -> Result<()> {
 
     Ok(())
 }
+
+#[tokio::test]
+async fn loader_works_via_proxy() -> Result<()> {
+    let wallet = launch_provider_and_get_wallet().await?;
+
+    abigen!(
+        Contract(
+            name = "MyContract",
+            abi = "e2e/sway/contracts/huge_contract/out/release/huge_contract-abi.json"
+        ),
+        Contract(
+            name = "MyProxy",
+            abi = "e2e/sway/contracts/proxy/out/release/proxy-abi.json"
+        )
+    );
+
+    let contract_binary = "sway/contracts/huge_contract/out/release/huge_contract.bin";
+
+    let contract = Contract::load_from(contract_binary, LoadConfiguration::default())?;
+
+    let contract_id = contract
+        .convert_to_loader(100)?
+        .deploy(&wallet, TxPolicies::default())
+        .await?;
+
+    let contract_binary = "sway/contracts/proxy/out/release/proxy.bin";
+
+    let proxy_id = Contract::load_from(contract_binary, LoadConfiguration::default())?
+        .deploy(&wallet, TxPolicies::default())
+        .await?;
+
+    let proxy = MyProxy::new(proxy_id, wallet.clone());
+    proxy
+        .methods()
+        .set_target_contract(contract_id.clone())
+        .call()
+        .await?;
+
+    let response = proxy
+        .methods()
+        .something()
+        .with_contract_ids(&[contract_id])
+        .call()
+        .await?
+        .value;
+
+    assert_eq!(response, 1001);
+
+    Ok(())
+}

packages/fuels-programs/src/contract/loader.rs

@@ -27,7 +27,7 @@ pub fn loader_contract_asm(blob_ids: &[BlobId]) -> Result<Vec<u8>> {
         [
             // 1. Load the blob contents into memory
             // Find the start of the hardcoded blob IDs, which are located after the code ends.
-            op::move_(0x10, RegId::IS),
+            op::move_(0x10, RegId::PC),
             // 0x10 to hold the address of the current blob ID.
             op::addi(0x10, 0x10, num_of_instructions * Instruction::SIZE as u16),
             // The contract is going to be loaded from the current value of SP onwards, save