Allow storage access in fallback only contracts (#6031)

## Description

Contract that do not implement any ABI (and therefore have no methods)
do not always properly set the storage annotations of the entry function
because the fallback function's storage annotations are not taken into
account. This changes makes sure that the storage function's storage
permissions are also considered.

We also change the code generation for the method selector to make
selection optional, such as for full passthrough proxies.


## Checklist

- [x] I have linked to any relevant issues.
- [x] I have commented my code, particularly in hard-to-understand
areas.
- [x] I have updated the documentation where relevant (API docs, the
reference, and the Sway book).
- [x] If my change requires substantial documentation changes, I have
[requested support from the DevRel
team](https://github.com/FuelLabs/devrel-requests/issues/new/choose)
- [x] I have added tests that prove my fix is effective or that my
feature works.
- [x] I have added (or requested a maintainer to add) the necessary
`Breaking*` or `New Feature` labels where relevant.
- [x] I have done my best to ensure that my PR adheres to [the Fuel Labs
Code Review
Standards](https://github.com/FuelLabs/rfcs/blob/master/text/code-standards/external-contributors.md).
- [x] I have requested a review from the relevant team or maintainers.

Co-authored-by: Joshua Batty <joshpbatty@gmail.com>

sway-core/src/semantic_analysis/ast_node/declaration/auto_impl.rs

@@ -628,27 +628,19 @@ where
             let method_name = decl.name.as_str();
 
             if args_types == "()" {
-                code.push_str(&format!("if method_name == \"{method_name}\" {{
+                code.push_str(&format!("if _method_name == \"{method_name}\" {{
                     let result_{method_name}: raw_slice = encode::<{return_type}>(__contract_entry_{method_name}());
                     __contract_ret(result_{method_name}.ptr(), result_{method_name}.len::<u8>());
                 }}\n"));
             } else {
-                code.push_str(&format!("if method_name == \"{method_name}\" {{
+                code.push_str(&format!("if _method_name == \"{method_name}\" {{
                     let args: {args_types} = decode_second_param::<{args_types}>();
                     let result_{method_name}: raw_slice = encode::<{return_type}>(__contract_entry_{method_name}({expanded_args}));
                     __contract_ret(result_{method_name}.ptr(), result_{method_name}.len::<u8>());
                 }}\n"));
             }
         }
 
-        let att: String = match (reads, writes) {
-            (true, true) => "#[storage(read, write)]",
-            (true, false) => "#[storage(read)]",
-            (false, true) => "#[storage(write)]",
-            (false, false) => "",
-        }
-        .into();
-
         let fallback = if let Some(fallback_fn) = fallback_fn {
             let fallback_fn = engines.de().get(&fallback_fn);
             let Some(return_type) = Self::generate_type(engines, fallback_fn.return_type.type_id)
@@ -659,16 +651,32 @@ where
                 return Err(err);
             };
             let method_name = fallback_fn.name.as_str();
-
+            match fallback_fn.purity {
+                Purity::Pure => {}
+                Purity::Reads => reads = true,
+                Purity::Writes => writes = true,
+                Purity::ReadsWrites => {
+                    reads = true;
+                    writes = true;
+                }
+            }
             format!("let result: raw_slice = encode::<{return_type}>({method_name}()); __contract_ret(result.ptr(), result.len::<u8>());")
         } else {
             // as the old encoding does
             format!("__revert({});", MISMATCHED_SELECTOR_REVERT_CODE)
         };
 
+        let att: String = match (reads, writes) {
+            (true, true) => "#[storage(read, write)]",
+            (true, false) => "#[storage(read)]",
+            (false, true) => "#[storage(write)]",
+            (false, false) => "",
+        }
+        .into();
+
         let code = format!(
             "{att} pub fn __entry() {{
-            let method_name = decode_first_param::<str>();
+            let _method_name = decode_first_param::<str>();
             {code}
             {fallback}
         }}"

test/src/e2e_vm_tests/test_programs/should_pass/language/fallback_only/Forc.lock

@@ -0,0 +1,16 @@
+[[package]]
+name = "core"
+source = "path+from-root-542D0E8F1D1E5950"
+
+[[package]]
+name = "fallback_only"
+source = "member"
+dependencies = [
+    "core",
+    "std",
+]
+
+[[package]]
+name = "std"
+source = "path+from-root-542D0E8F1D1E5950"
+dependencies = ["core"]

test/src/e2e_vm_tests/test_programs/should_pass/language/fallback_only/Forc.toml

@@ -0,0 +1,10 @@
+[project]
+authors = ["Fuel Labs <contact@fuel.sh>"]
+entry = "main.sw"
+license = "Apache-2.0"
+name = "fallback_only"
+implicit-std = false
+
+[dependencies]
+core = { path = "../../../../../../../sway-lib-core" }
+std = { path = "../../../../../../../sway-lib-std" }

test/src/e2e_vm_tests/test_programs/should_pass/language/fallback_only/json_abi_oracle.json

@@ -0,0 +1,8 @@
+{
+  "configurables": [],
+  "encoding": "1",
+  "functions": [],
+  "loggedTypes": [],
+  "messagesTypes": [],
+  "types": []
+}

test/src/e2e_vm_tests/test_programs/should_pass/language/fallback_only/json_abi_oracle_new_encoding.json

@@ -0,0 +1,8 @@
+{
+  "configurables": [],
+  "encoding": "1",
+  "functions": [],
+  "loggedTypes": [],
+  "messagesTypes": [],
+  "types": []
+}

test/src/e2e_vm_tests/test_programs/should_pass/language/fallback_only/src/main.sw

@@ -0,0 +1,15 @@
+contract;
+
+use std::execution::run_external;
+use std::constants::ZERO_B256;
+
+#[namespace(SRC1822)]
+storage {
+    target: ContractId = ContractId::from(ZERO_B256),
+}
+
+#[fallback]
+#[storage(read)]
+fn fallback() {
+    run_external(storage.target.read())
+}

test/src/e2e_vm_tests/test_programs/should_pass/language/fallback_only/test.toml

@@ -0,0 +1,3 @@
+category = "compile"
+validate_abi = true
+expected_warnings = 0

test/src/e2e_vm_tests/test_programs/should_pass/require_contract_deployment/array_of_structs_caller/src/main.sw

@@ -4,9 +4,9 @@ use array_of_structs_abi::{Id, TestContract, Wrapper};
 use std::hash::*;
 
 #[cfg(experimental_new_encoding = false)]
-const CONTRACT_ID = 0x7fae96947a8cad59cc2a25239f9f80897955d4c1b10d31510681f15842b93265;
+const CONTRACT_ID = 0x14ed3cd06c2947248f69d54bfa681fe40d26267be84df7e19e253622b7921bbe;
 #[cfg(experimental_new_encoding = true)]
-const CONTRACT_ID = 0xe47e8943692557f67104afff960cb54e2d6d74b24aeefd8c2efeccad4e093bc0;
+const CONTRACT_ID = 0xa5c32c71e9e1ecb39b04182b4e8b0582d1685dea7accbee94dc3be867a68c93f;
 
 fn main() -> u64 {
     let addr = abi(TestContract, CONTRACT_ID);

test/src/e2e_vm_tests/test_programs/should_pass/require_contract_deployment/asset_ops_test/src/main.sw

@@ -7,14 +7,14 @@ use std::constants::DEFAULT_SUB_ID;
 use test_fuel_coin_abi::*;
 
 #[cfg(experimental_new_encoding = false)]
-const FUEL_COIN_CONTRACT_ID = 0x9e84e7e3006c94d5e23545829dbc926f50f90c6809c6e599ecddbf9a119e8104;
+const FUEL_COIN_CONTRACT_ID = 0x4c7b43ef5a097d7cfb87600a4234e33311eeeeb8081e5ea7bb6d9a1f8555c9c4;
 #[cfg(experimental_new_encoding = true)]
-const FUEL_COIN_CONTRACT_ID = 0x47844008800c6f17ae24a30425094d733ca7a767cf2a915c8d5f73e3ff8f952b;
+const FUEL_COIN_CONTRACT_ID = 0x5ad3dfd3def1db21312d64d274ec34924fc62b8126be51b8000b0c20a953c27a;
 
 #[cfg(experimental_new_encoding = false)]
-const BALANCE_CONTRACT_ID = 0x3b8cb681056f61a41e138b8884d7e3bb9332fbd7a8e38e3e0b0ada766cabfa4e;
+const BALANCE_CONTRACT_ID = 0x3120fdd1b99c0c611308aff43a99746cc2c661c69c22aa56331d5f3ce5534ee9;
 #[cfg(experimental_new_encoding = true)]
-const BALANCE_CONTRACT_ID = 0xd354c2c31bb641863d03eaf320488ae276386ce60ef2e561258efef617dab462;
+const BALANCE_CONTRACT_ID = 0x2393ab4d437acea9f3e916ddd728218ac2dca45dcfabe3b2fe83926a4dc0e737;
 
 fn main() -> bool {
     let default_gas = 1_000_000_000_000;
@@ -65,4 +65,4 @@ fn main() -> bool {
     assert(balance_test_contract_balance == 3);
 
     true
-}
+}

test/src/e2e_vm_tests/test_programs/should_pass/require_contract_deployment/bal_opcode/src/main.sw

@@ -3,9 +3,9 @@ script;
 use balance_test_abi::BalanceTest;
 
 #[cfg(experimental_new_encoding = false)]
-const CONTRACT_ID = 0x3b8cb681056f61a41e138b8884d7e3bb9332fbd7a8e38e3e0b0ada766cabfa4e;
+const CONTRACT_ID = 0x3120fdd1b99c0c611308aff43a99746cc2c661c69c22aa56331d5f3ce5534ee9;
 #[cfg(experimental_new_encoding = true)]
-const CONTRACT_ID = 0xd354c2c31bb641863d03eaf320488ae276386ce60ef2e561258efef617dab462;
+const CONTRACT_ID = 0x2393ab4d437acea9f3e916ddd728218ac2dca45dcfabe3b2fe83926a4dc0e737;
 
 fn main() -> bool {
     let balance_test_contract = abi(BalanceTest, CONTRACT_ID);

test/src/e2e_vm_tests/test_programs/should_pass/require_contract_deployment/call_basic_storage/src/main.sw

@@ -2,9 +2,9 @@ script;
 use basic_storage_abi::{BasicStorage, Quad};
 
 #[cfg(experimental_new_encoding = false)]
-const CONTRACT_ID = 0x5c0aef0c1af7601aa6b9fa0fc9efff0e956dcb93f855788222e172e67e717072;
+const CONTRACT_ID = 0x044ab65bcabeebb73c88d8625ce392224c613cb1dae21ebedaa36bf6db1f5f4e;
 #[cfg(experimental_new_encoding = true)]
-const CONTRACT_ID = 0x37cdef21aab78b40f27486172cd39a320539de08b625e22d877e2bed6b826250;
+const CONTRACT_ID = 0x70ea1e451bfa81030215e245f8644aef00043b50c16da4c5ab91fd32ff89a9d1;
 
 fn main() -> u64 {
     let addr = abi(BasicStorage, CONTRACT_ID);

test/src/e2e_vm_tests/test_programs/should_pass/require_contract_deployment/call_contract_with_type_aliases/src/main.sw

@@ -3,9 +3,9 @@ script;
 use contract_with_type_aliases_abi::*;
 
 #[cfg(experimental_new_encoding = false)]
-const CONTRACT_ID = 0x9d76ecbf446c30ef659efd1157d67d156de02b1e6c2ac2f9c744125571efa229;
+const CONTRACT_ID = 0x0cbeb6efe3104b460be769bdc4ea101ebf16ccc16f2d7b667ec3e1c7f5ce35b5;
 #[cfg(experimental_new_encoding = true)]
-const CONTRACT_ID = 0x4c4bd277507ce1d47cbe793a8db2255ed44da30acacedb5e6aa565f7417ad3c8;
+const CONTRACT_ID = 0x9e03072a3f094ed4b5af0ca6e1c244bafe8ded847d2c04aab331a9236ae7166a;
 
 fn main() {
     let caller = abi(MyContract, CONTRACT_ID);

test/src/e2e_vm_tests/test_programs/should_pass/require_contract_deployment/call_storage_enum/src/main.sw

@@ -3,9 +3,9 @@ script;
 use storage_enum_abi::*;
 
 #[cfg(experimental_new_encoding = false)]
-const CONTRACT_ID = 0x0436d54f976e2dee0d77c81abc0d32cc7be985d8e0c97eeba27acd1caffdcea1;
+const CONTRACT_ID = 0x0d2d9546e833c166b64a340f5694fa01ca6bb53c3ec681d6c1ade1b9c0a2bf46;
 #[cfg(experimental_new_encoding = true)]
-const CONTRACT_ID = 0xb19179a1379ccc402a3913d5cbaffd13ce7599218b6010b54ffaf22bca68fcf1;
+const CONTRACT_ID = 0x53d4ee67238f0fbbcd2cdf1eff3115da320f3e893c70925d0f05b8cac72dd987;
 
 fn main() -> u64 {
     let caller = abi(StorageEnum, CONTRACT_ID);

test/src/e2e_vm_tests/test_programs/should_pass/require_contract_deployment/caller_auth_test/src/main.sw

@@ -3,9 +3,9 @@ script;
 use auth_testing_abi::AuthTesting;
 
 #[cfg(experimental_new_encoding = false)]
-const CONTRACT_ID = 0xd7ef57c654a7e52ee8b85f34c64fa2f8e1a250eceb446cfe9805b175a0a7680f;
+const CONTRACT_ID = 0xc2eec20491b53aab7232cbd27c31d15417b4e9daf0b89c74cc242ef1295f681f;
 #[cfg(experimental_new_encoding = true)]
-const CONTRACT_ID = 0xe453d2444c24bc0972b7a9cd25bdaaacc501bc2cef9e0aa577fffb5984e068f5;
+const CONTRACT_ID = 0xd0b3be215b9f4f9a49af510c8a4f0b1f43ba640a73c6b6ea8a68a37fe71a27af;
 
 // should be false in the case of a script
 fn main() -> bool {

test/src/e2e_vm_tests/test_programs/should_pass/require_contract_deployment/caller_context_test/src/main.sw

@@ -4,9 +4,9 @@ use core::codec::*;
 use context_testing_abi::*;
 
 #[cfg(experimental_new_encoding = false)]
-const CONTRACT_ID = 0xe83ed45906627117f00f60e47140c6100b4b69133389a2dafd35bc3282329385;
+const CONTRACT_ID = 0xc2ec2a4a1b20475700e6793c7f20ad8082294894242b17cf08b5fd7c0d3968ad;
 #[cfg(experimental_new_encoding = true)]
-const CONTRACT_ID = 0xf94d4eb2fb56ff3a5b85d6b853a6ea874846b22d71005611b95ed9aefc65b160;
+const CONTRACT_ID = 0xc3ad47dc59ab201f60a87428fbcecdde4f33b0b31eb3aee6670ea924c6fd82fa;
 
 fn main() -> bool {
     let gas: u64 = u64::max();

test/src/e2e_vm_tests/test_programs/should_pass/require_contract_deployment/nested_struct_args_caller/src/main.sw

@@ -3,9 +3,9 @@ script;
 use nested_struct_args_abi::*;
 
 #[cfg(experimental_new_encoding = false)]
-const CONTRACT_ID = 0xc615be7b48402210cbec3bc1667ab5a8093d449d5d8d1fdcc26e6f18e7942ea9;
+const CONTRACT_ID = 0x64390eb0cac08d41b6476ad57d711b88846ea35ac800d4fc3c95a551e4039432;
 #[cfg(experimental_new_encoding = true)]
-const CONTRACT_ID = 0x8341183f70e4b6a4750b2e5806c2146e4b78d6873fed172767718deb206e3d24;
+const CONTRACT_ID = 0xf12a88781f67f3ce2cdb4994e3571a6b42176c9ce63e3fdeb0247b1f319a8d83;
 
 fn main() -> bool {
     let caller = abi(NestedStructArgs, CONTRACT_ID);

test/src/e2e_vm_tests/test_programs/should_pass/require_contract_deployment/storage_access_caller/src/main.sw

@@ -4,9 +4,9 @@ use storage_access_abi::*;
 use std::hash::*;
 
 #[cfg(experimental_new_encoding = false)]
-const CONTRACT_ID = 0x0a58692bee60559887f0ac181c8a3b14ffb7a3a66256eec3f08e3135bfbecac9;
+const CONTRACT_ID = 0x88732a14508defea37a44d0b0ae9af5c776253215180a1c3288f8d504ebb84db;
 #[cfg(experimental_new_encoding = true)]
-const CONTRACT_ID = 0x8ae216e6df492a4a983c34c5871bbe84c6aafa70fa25f1d76b771d8c8a72a1d7;
+const CONTRACT_ID = 0xdebe2a83a36d9201ec836181ee0e013d6279a1a96dd039f7f701940d83b728e9;
 
 fn main() -> bool {
     let caller = abi(StorageAccess, CONTRACT_ID);

test/src/e2e_vm_tests/test_programs/should_pass/unit_tests/workspace_test/contract_multi_test/src/main.sw

@@ -17,15 +17,15 @@ fn test_foo() {
 
 #[test(should_revert)]
 fn test_fail() {
-    let contract_id = 0x535d1bbf19a6c7e5e2e2906d09b8c959bd211391e7a3c7602c5dab0455f78305;
+    let contract_id = 0xed94087f1dea86a4590624880f80e97522daedb48a2398a37f6aa039599715ef;
     let caller = abi(MyContract, contract_id);
     let result = caller.test_function {}();
     assert(result == false)
 }
 
 #[test]
 fn test_success() {
-    let contract_id = 0x535d1bbf19a6c7e5e2e2906d09b8c959bd211391e7a3c7602c5dab0455f78305;
+    let contract_id = 0xed94087f1dea86a4590624880f80e97522daedb48a2398a37f6aa039599715ef;
     let caller = abi(MyContract, contract_id);
     let result = caller.test_function {}();
     assert(result == true)