support the origin opcode (#103)

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

crates/integration/contracts/Transaction.sol

@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+/* runner.json
+{
+    "differential": true,
+    "actions": [
+        {
+            "Upload": {
+                "code": {
+                    "Solidity": {
+                        "contract": "TransactionOrigin"
+                    }
+                }
+            }
+        },
+        {
+            "Instantiate": {
+                "code": {
+                    "Solidity": {
+                        "contract": "TransactionTester"
+                    }
+                }
+            }
+        },
+        {
+            "Call": {
+                "dest": {
+                    "Instantiated": 0
+                },
+                "data": "f8a8fd6d"
+            }
+        }
+    ]
+}
+*/
+
+contract TransactionTester {
+    constructor() payable {
+        assert(tx.origin == new TransactionOrigin().test());
+    }
+
+    function test() public payable returns (address ret) {
+        ret = tx.origin;
+    }
+}
+
+contract TransactionOrigin {
+    function test() public payable returns (address ret) {
+        assert(msg.sender != tx.origin);
+
+        ret = tx.origin;
+    }
+}

crates/integration/src/tests.rs

@@ -43,6 +43,7 @@ test_spec!(call, "Caller", "Call.sol");
 test_spec!(transfer, "Transfer", "Transfer.sol");
 test_spec!(return_data_oob, "ReturnDataOob", "ReturnDataOob.sol");
 test_spec!(immutables, "Immutables", "Immutables.sol");
+test_spec!(transaction, "Transaction", "Transaction.sol");
 
 fn instantiate(path: &str, contract: &str) -> Vec<SpecsAction> {
     vec![Instantiate {

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

@@ -27,12 +27,19 @@ where
 
 /// Translates the `tx.origin` instruction.
 pub fn origin<'ctx, D>(
-    _context: &mut Context<'ctx, D>,
+    context: &mut Context<'ctx, D>,
 ) -> anyhow::Result<inkwell::values::BasicValueEnum<'ctx>>
 where
     D: Dependency + Clone,
 {
-    todo!()
+    let address_type = context.integer_type(revive_common::BIT_LENGTH_ETH_ADDRESS);
+    let address_pointer = context.build_alloca_at_entry(address_type, "origin_address");
+    context.build_store(address_pointer, address_type.const_zero())?;
+    context.build_runtime_call(
+        revive_runtime_api::polkavm_imports::ORIGIN,
+        &[address_pointer.to_int(context).into()],
+    );
+    context.build_load_address(address_pointer)
 }
 
 /// Translates the `chain_id` instruction.

crates/runtime-api/src/polkavm_imports.c

@@ -96,6 +96,8 @@ POLKAVM_IMPORT(uint32_t, instantiate, uint32_t)
 
 POLKAVM_IMPORT(void, now, uint32_t)
 
+POLKAVM_IMPORT(void, origin, uint32_t)
+
 POLKAVM_IMPORT(void, seal_return, uint32_t, uint32_t, uint32_t)
 
 POLKAVM_IMPORT(uint32_t, set_storage, uint32_t, uint32_t, uint32_t, uint32_t, uint32_t)

crates/runtime-api/src/polkavm_imports.rs

@@ -46,6 +46,8 @@ pub static INSTANTIATE: &str = "instantiate";
 
 pub static NOW: &str = "now";
 
+pub static ORIGIN: &str = "origin";
+
 pub static RETURN: &str = "seal_return";
 
 pub static SET_STORAGE: &str = "set_storage";
@@ -60,7 +62,7 @@ pub static VALUE_TRANSFERRED: &str = "value_transferred";
 
 /// All imported runtime API symbols.
 /// Useful for configuring common attributes and linkage.
-pub static IMPORTS: [&str; 24] = [
+pub static IMPORTS: [&str; 25] = [
     SBRK,
     MEMORY_SIZE,
     ADDRESS,
@@ -79,6 +81,7 @@ pub static IMPORTS: [&str; 24] = [
     INPUT,
     INSTANTIATE,
     NOW,
+    ORIGIN,
     RETURN,
     RETURNDATACOPY,
     RETURNDATASIZE,