switch to the new storage API (#396)

This PR switches to the new `get_storage_or_zero` and
`set_storage_or_clear` syscalls which are more tailored towards
Solidity.

Signed-off-by: Cyrill Leutwiler <bigcyrill@hotmail.com>

crates/integration/codesize.json

@@ -2,9 +2,9 @@
   "Baseline": 914,
   "Computation": 2295,
   "DivisionArithmetics": 14510,
-  "ERC20": 17499,
+  "ERC20": 17482,
   "Events": 1674,
   "FibonacciIterative": 1490,
-  "Flipper": 2102,
+  "Flipper": 2086,
   "SHA1": 8158
 }

crates/llvm-context/src/polkavm/context/pointer/storage.rs

@@ -157,6 +157,10 @@ fn emit_load<'ctx>(
     key: BasicValueEnum<'ctx>,
     transient: bool,
 ) -> anyhow::Result<BasicValueEnum<'ctx>> {
+    let is_transient = context.xlen_type().const_int(transient as u64, false);
+    let key_pointer = context.build_alloca_at_entry(context.word_type(), "key_pointer");
+    let value_pointer = context.build_alloca_at_entry(context.word_type(), "value_pointer");
+
     let mut key = context.build_load(
         super::Pointer::new(
             context.word_type(),
@@ -168,33 +172,17 @@ fn emit_load<'ctx>(
     if !transient {
         key = context.build_byte_swap(key)?;
     }
-
-    let key_pointer = context.build_alloca_at_entry(context.word_type(), "key_pointer");
-    let value_pointer = context.build_alloca_at_entry(context.word_type(), "value_pointer");
-    let length_pointer = context.build_alloca_at_entry(context.xlen_type(), "length_pointer");
-
     context.builder().build_store(key_pointer.value, key)?;
-    context.build_store(value_pointer, context.word_const(0))?;
-    context.build_store(
-        length_pointer,
-        context
-            .xlen_type()
-            .const_int(revive_common::BYTE_LENGTH_WORD as u64, false),
-    )?;
-
-    let is_transient = context.xlen_type().const_int(transient as u64, false);
 
     let arguments = [
         is_transient.into(),
         key_pointer.to_int(context).into(),
-        context.xlen_type().const_all_ones().into(),
         value_pointer.to_int(context).into(),
-        length_pointer.to_int(context).into(),
     ];
     context.build_runtime_call(revive_runtime_api::polkavm_imports::GET_STORAGE, &arguments);
 
     // We do not to check the return value: Solidity assumes infallible loads.
-    // If a key doesn't exist the "zero" value is returned (ensured by above write).
+    // If a key doesn't exist the syscall returns zero.
 
     let value = context.build_load(value_pointer, "storage_value")?;
     Ok(if transient {
@@ -210,6 +198,10 @@ fn emit_store<'ctx>(
     value: BasicValueEnum<'ctx>,
     transient: bool,
 ) -> anyhow::Result<()> {
+    let is_transient = context.xlen_type().const_int(transient as u64, false);
+    let key_pointer = context.build_alloca_at_entry(context.word_type(), "key_pointer");
+    let value_pointer = context.build_alloca_at_entry(context.word_type(), "value_pointer");
+
     let mut key = context.build_load(
         super::Pointer::new(
             context.word_type(),
@@ -224,27 +216,20 @@ fn emit_store<'ctx>(
             Default::default(),
             value.into_pointer_value(),
         ),
-        "key",
+        "value",
     )?;
     if !transient {
         key = context.build_byte_swap(key)?;
         value = context.build_byte_swap(value)?;
     }
 
-    let key_pointer = context.build_alloca_at_entry(context.word_type(), "key_pointer");
-    let value_pointer = context.build_alloca_at_entry(context.word_type(), "value_pointer");
-
     context.build_store(key_pointer, key)?;
     context.build_store(value_pointer, value)?;
 
-    let is_transient = context.xlen_type().const_int(transient as u64, false);
-
     let arguments = [
         is_transient.into(),
         key_pointer.to_int(context).into(),
-        context.xlen_type().const_all_ones().into(),
         value_pointer.to_int(context).into(),
-        context.integer_const(crate::polkavm::XLEN, 32).into(),
     ];
     context.build_runtime_call(revive_runtime_api::polkavm_imports::SET_STORAGE, &arguments);
 

crates/runner/src/specs.rs

@@ -510,13 +510,10 @@ impl Specs {
                             expected,
                         } => {
                             let address = contract.to_eth_addr(&results);
-                            let Ok(value) = Contracts::get_storage(address, key) else {
+                            let value = Contracts::get_storage(address, key)
-                                panic!("error reading storage for address {address}");
+                                .unwrap_or_else(|error| panic!("at {address}: {error:?}"))
-                            };
+                                .unwrap_or_else(|| vec![0; 32]);
-                            let Some(value) = value else {
+                            assert_eq!(value, expected, "at {address} key 0x{}", hex::encode(key));
-                                panic!("no value at {address} key 0x{}", hex::encode(key));
-                            };
-                            assert_eq!(value, expected, "at key 0x{}", hex::encode(key));
                         }
                     }
                 }

crates/runtime-api/src/polkavm_imports.c

@@ -79,7 +79,7 @@ POLKAVM_IMPORT(uint64_t, gas_price);
 
 POLKAVM_IMPORT(void, get_immutable_data, uint32_t, uint32_t);
 
-POLKAVM_IMPORT(uint64_t, get_storage, uint32_t, uint32_t, uint32_t, uint32_t, uint32_t)
+POLKAVM_IMPORT(uint64_t, get_storage_or_zero, uint32_t, uint32_t, uint32_t)
 
 POLKAVM_IMPORT(void, hash_keccak_256, uint32_t, uint32_t, uint32_t)
 
@@ -99,7 +99,7 @@ POLKAVM_IMPORT(uint64_t, return_data_size)
 
 POLKAVM_IMPORT(void, set_immutable_data, uint32_t, uint32_t);
 
-POLKAVM_IMPORT(uint64_t, set_storage, uint32_t, uint32_t, uint32_t, uint32_t, uint32_t)
+POLKAVM_IMPORT(uint64_t, set_storage_or_clear, uint32_t, uint32_t, uint32_t)
 
 POLKAVM_IMPORT(void, value_transferred, uint32_t)
 

crates/runtime-api/src/polkavm_imports.rs

@@ -42,7 +42,7 @@ pub static GAS_PRICE: &str = "gas_price";
 
 pub static GET_IMMUTABLE_DATA: &str = "get_immutable_data";
 
-pub static GET_STORAGE: &str = "get_storage";
+pub static GET_STORAGE: &str = "get_storage_or_zero";
 
 pub static HASH_KECCAK_256: &str = "hash_keccak_256";
 
@@ -62,7 +62,7 @@ pub static RETURNDATASIZE: &str = "return_data_size";
 
 pub static SET_IMMUTABLE_DATA: &str = "set_immutable_data";
 
-pub static SET_STORAGE: &str = "set_storage";
+pub static SET_STORAGE: &str = "set_storage_or_clear";
 
 pub static VALUE_TRANSFERRED: &str = "value_transferred";