events

Signed-off-by: xermicus <cyrill@parity.io>

crates/differential/src/lib.rs

@@ -10,7 +10,10 @@ use primitive_types::{H160, H256, U256};
 static RUNTIME_ETABLE: Etable<RuntimeState, UnimplementedHandler, CallCreateTrap> =
     Etable::runtime();
 
-pub struct UnimplementedHandler;
+#[derive(Default)]
+pub struct UnimplementedHandler {
+    logs: Vec<Log>,
+}
 
 impl RuntimeEnvironment for UnimplementedHandler {
     fn block_hash(&self, _number: U256) -> H256 {
@@ -87,8 +90,9 @@ impl RuntimeBackend for UnimplementedHandler {
     fn set_storage(&mut self, _address: H160, _index: H256, _value: H256) -> Result<(), ExitError> {
         unimplemented!()
     }
-    fn log(&mut self, _log: Log) -> Result<(), ExitError> {
-        unimplemented!()
+    fn log(&mut self, log: Log) -> Result<(), ExitError> {
+        self.logs.push(log);
+        Ok(())
     }
     fn mark_delete(&mut self, _address: H160) {
         unimplemented!()
@@ -147,12 +151,9 @@ pub fn prepare(code: Vec<u8>, data: Vec<u8>) -> PreparedEvm {
     }
 }
 
-pub fn execute(pre: PreparedEvm) -> Vec<u8> {
+pub fn execute(pre: PreparedEvm) -> (Vec<u8>, Vec<Log>) {
     let mut vm = EtableInterpreter::new_valid(pre.vm, &RUNTIME_ETABLE, pre.valids);
-    vm.run(&mut UnimplementedHandler {})
-        .exit()
-        .unwrap()
-        .unwrap();
-
-    vm.retval.clone()
+    let mut handler = UnimplementedHandler::default();
+    vm.run(&mut handler).exit().unwrap().unwrap();
+    (vm.retval.clone(), handler.logs)
 }

crates/integration/codesize.json

@@ -2,7 +2,8 @@
   "Baseline": 3944,
   "Computation": 7444,
   "DivisionArithmetics": 42784,
-  "ERC20": 53524,
+  "ERC20": 56199,
+  "Events": 4784,
   "FibonacciIterative": 6019,
   "Flipper": 4392,
   "SHA1": 36107

crates/integration/contracts/DivisionArithmetics.sol

@@ -1,3 +1,7 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8;
+
 contract DivisionArithmetics {
     function div(uint n, uint d) public pure returns (uint q) {
         assembly {

crates/integration/contracts/Events.sol

@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8;
+
+contract Events {
+    event A() anonymous;
+    event E(uint, uint indexed, uint indexed, uint indexed);
+
+    function emitEvent(uint topics) public {
+        if (topics == 0) {
+            emit A();
+        } else {
+            emit E(topics, 1, 2, 3);
+        }
+    }
+}

crates/integration/src/cases.rs

@@ -104,6 +104,15 @@ sol!(
     }
 );
 
+sol!(
+    contract Events {
+        event A(uint) anonymous;
+        event E(uint indexed, uint indexed, uint indexed);
+
+        function emitEvent(uint topics) public;
+    }
+);
+
 impl Contract {
     /// Execute the contract.
     ///
@@ -338,6 +347,18 @@ impl Contract {
             calldata: MStore8::mStore8Call::new((value,)).abi_encode(),
         }
     }
+
+    pub fn event(topics: U256) -> Self {
+        let code = include_str!("../contracts/Events.sol");
+        let name = "Events";
+
+        Self {
+            name,
+            evm_runtime: crate::compile_evm_bin_runtime(name, code),
+            pvm_runtime: crate::compile_blob(name, code),
+            calldata: Events::emitEventCall::new((topics,)).abi_encode(),
+        }
+    }
 }
 
 #[cfg(test)]
@@ -389,6 +410,7 @@ mod tests {
             Contract::erc20 as fn() -> Contract,
             (|| Contract::sha1(Vec::new())) as fn() -> Contract,
             (|| Contract::division_arithmetics_div(U256::ZERO, U256::ZERO)) as fn() -> Contract,
+            (|| Contract::event(U256::ZERO)) as fn() -> Contract,
         ]
         .into_par_iter()
         .map(extract_code_size)

crates/integration/src/lib.rs

@@ -1,7 +1,8 @@
+use alloy_primitives::{Address, U256};
 use cases::Contract;
 use mock_runtime::{CallOutput, State};
 
-use crate::mock_runtime::ReturnFlags;
+use crate::mock_runtime::{Event, ReturnFlags};
 
 pub mod cases;
 pub mod mock_runtime;
@@ -82,7 +83,25 @@ pub fn assert_success(contract: &Contract, differential: bool) -> (State, CallOu
     if differential {
         let evm =
             revive_differential::prepare(contract.evm_runtime.clone(), contract.calldata.clone());
-        assert_eq!(output.data.clone(), revive_differential::execute(evm));
+        let (evm_output, evm_log) = revive_differential::execute(evm);
+
+        assert_eq!(output.data.clone(), evm_output);
+        assert_eq!(output.events.len(), evm_log.len());
+        assert_eq!(
+            output.events,
+            evm_log
+                .iter()
+                .map(|log| Event {
+                    address: Address::from_slice(log.address.as_bytes()),
+                    data: log.data.clone(),
+                    topics: log
+                        .topics
+                        .iter()
+                        .map(|topic| U256::from_be_bytes(topic.0))
+                        .collect(),
+                })
+                .collect::<Vec<_>>()
+        );
     }
 
     (state, output)

crates/integration/src/mock_runtime.rs

@@ -17,8 +17,9 @@ struct Account {
 }
 
 /// Emitted event data.
-#[derive(Debug, Default, Clone)]
+#[derive(Debug, Default, Clone, PartialEq)]
 pub struct Event {
+    pub address: Address,
     pub data: Vec<u8>,
     pub topics: Vec<U256>,
 }
@@ -31,7 +32,7 @@ pub struct CallOutput {
     /// The contract call output.
     pub data: Vec<u8>,
     /// The emitted events.
-    pub events: Event,
+    pub events: Vec<Event>,
 }
 
 /// The contract blob export to be called.
@@ -570,6 +571,43 @@ fn link_host_functions(engine: &Engine) -> Linker<Transaction> {
         )
         .unwrap();
 
+    linker
+        .func_wrap(
+            runtime_api::DEPOSIT_EVENT,
+            |caller: Caller<Transaction>,
+             topics_ptr: u32,
+             topics_len: u32,
+             data_ptr: u32,
+             data_len: u32| {
+                let (caller, transaction) = caller.split();
+
+                let address = transaction.top_frame().callee;
+                let data = if data_len != 0 {
+                    caller.read_memory_into_vec(data_ptr, data_len)?
+                } else {
+                    Default::default()
+                };
+                let topics = if topics_len != 0 {
+                    caller
+                        .read_memory_into_vec(topics_ptr, topics_len)?
+                        .chunks(32)
+                        .map(|chunk| U256::from_be_slice(chunk))
+                        .collect()
+                } else {
+                    Default::default()
+                };
+
+                transaction.top_frame_mut().output.events.push(Event {
+                    address,
+                    data,
+                    topics,
+                });
+
+                Ok(())
+            },
+        )
+        .unwrap();
+
     linker
 }
 

crates/integration/src/tests.rs

@@ -415,3 +415,9 @@ fn signed_remainder() {
         assert_eq!(received, expected);
     }
 }
+
+#[test]
+fn events() {
+    assert_success(&Contract::event(U256::ZERO), true);
+    assert_success(&Contract::event(U256::from(123)), true);
+}

crates/llvm-context/src/polkavm/const/runtime_api.rs

@@ -16,6 +16,8 @@ pub static BLOCK_NUMBER: &str = "block_number";
 
 pub static CALLER: &str = "caller";
 
+pub static DEPOSIT_EVENT: &str = "deposit_event";
+
 pub static GET_STORAGE: &str = "get_storage";
 
 pub static HASH_KECCAK_256: &str = "hash_keccak_256";
@@ -32,10 +34,15 @@ pub static VALUE_TRANSFERRED: &str = "value_transferred";
 
 /// All imported runtime API symbols..
 /// Useful for configuring common attributes and linkage.
-pub static IMPORTS: [&str; 6] = [
+pub static IMPORTS: [&str; 11] = [
+    ADDRESS,
+    BLOCK_NUMBER,
+    CALLER,
+    DEPOSIT_EVENT,
     GET_STORAGE,
     HASH_KECCAK_256,
     INPUT,
+    NOW,
     RETURN,
     SET_STORAGE,
     VALUE_TRANSFERRED,

crates/llvm-context/src/polkavm/evm/event.rs

@@ -1,72 +1,80 @@
 //! Translates a log or event call.
 
+use inkwell::values::BasicValue;
+
 use crate::polkavm::context::Context;
 use crate::polkavm::Dependency;
+use crate::polkavm_const::runtime_api;
 
 /// Translates a log or event call.
-/// The decoding logic is implemented in a system contract, which is called from here.
-/// There are several cases of the translation for the sake of efficiency, since the front-end
-/// emits topics and values sequentially by one, but the LLVM intrinsic and bytecode instruction
-/// accept two at once.
+///
+/// TODO: Splitting up into dedicated functions (log0..log4)
+/// could potentially decrease code sizes (LLVM can still decide to inline).
+/// However, passing many i256 parameters could also hurt a bit.
+/// Should be reviewed after 64bit support.
 pub fn log<'ctx, D>(
-    _context: &mut Context<'ctx, D>,
-    _input_offset: inkwell::values::IntValue<'ctx>,
-    _input_length: inkwell::values::IntValue<'ctx>,
-    _topics: Vec<inkwell::values::IntValue<'ctx>>,
+    context: &mut Context<'ctx, D>,
+    input_offset: inkwell::values::IntValue<'ctx>,
+    input_length: inkwell::values::IntValue<'ctx>,
+    topics: Vec<inkwell::values::IntValue<'ctx>>,
 ) -> anyhow::Result<()>
 where
     D: Dependency + Clone,
 {
-    /*
-    let failure_block = context.append_basic_block("event_failure_block");
-    let join_block = context.append_basic_block("event_join_block");
-
-    let gas = crate::polkavm::evm::ether_gas::gas(context)?.into_int_value();
-    let abi_data = crate::polkavm::utils::abi_data(
-        context,
-        input_offset,
-        input_length,
-        Some(gas),
-        AddressSpace::Heap,
-        true,
-    )?;
-    let mut extra_abi_data = Vec::with_capacity(1 + topics.len());
-    extra_abi_data.push(context.field_const(topics.len() as u64));
-    extra_abi_data.extend(topics);
-
-    let result = context
-        .build_call(
-            context.llvm_runtime().far_call,
-            crate::polkavm::utils::external_call_arguments(
-                context,
-                abi_data.as_basic_value_enum(),
-                context.field_const(zkevm_opcode_defs::ADDRESS_EVENT_WRITER as u64),
-                extra_abi_data,
-                None,
-            )
-            .as_slice(),
-            "event_writer_call_external",
-        )
-        .expect("Always returns a value");
-
-    let result_status_code_boolean = context
-        .builder()
-        .build_extract_value(
-            result.into_struct_value(),
-            1,
-            "event_writer_external_result_status_code_boolean",
-        )
-        .expect("Always exists");
-    context.build_conditional_branch(
-        result_status_code_boolean.into_int_value(),
-        join_block,
-        failure_block,
+    let input_offset = context.safe_truncate_int_to_xlen(input_offset)?;
+    let input_length = context.safe_truncate_int_to_xlen(input_length)?;
+    let input_pointer = context.builder().build_ptr_to_int(
+        context.build_heap_gep(input_offset, input_length)?.value,
+        context.xlen_type(),
+        "event_input_offset",
     )?;
 
-    context.set_basic_block(failure_block);
-    crate::polkavm::evm::r#return::revert(context, context.field_const(0), context.field_const(0))?;
+    let arguments = if topics.is_empty() {
+        [
+            context.xlen_type().const_zero().as_basic_value_enum(),
+            context.xlen_type().const_zero().as_basic_value_enum(),
+            input_pointer.as_basic_value_enum(),
+            input_length.as_basic_value_enum(),
+        ]
+    } else {
+        let topics_buffer_size = topics.len() * revive_common::BYTE_LENGTH_WORD;
+        let topics_buffer_pointer = context.build_alloca(
+            context.byte_type().array_type(topics_buffer_size as u32),
+            "topics_buffer",
+        );
+        for (n, topic) in topics.iter().enumerate() {
+            let topic_buffer_offset = context
+                .xlen_type()
+                .const_int((n * revive_common::BYTE_LENGTH_WORD) as u64, false);
+            context.build_store(
+                context.build_gep(
+                    topics_buffer_pointer,
+                    &[context.xlen_type().const_zero(), topic_buffer_offset],
+                    context.byte_type(),
+                    "topic_buffer_gep",
+                ),
+                context.build_byte_swap(topic.as_basic_value_enum())?,
+            )?;
+        }
+        [
+            context
+                .builder()
+                .build_ptr_to_int(
+                    topics_buffer_pointer.value,
+                    context.xlen_type(),
+                    "event_topics_offset",
+                )?
+                .as_basic_value_enum(),
+            context
+                .xlen_type()
+                .const_int(topics_buffer_size as u64, false)
+                .as_basic_value_enum(),
+            input_pointer.as_basic_value_enum(),
+            input_length.as_basic_value_enum(),
+        ]
+    };
+
+    let _ = context.build_runtime_call(runtime_api::DEPOSIT_EVENT, &arguments);
 
-    context.set_basic_block(join_block);
-    */
     Ok(())
 }