Support for EIP-1344 CHAINID opcode

CHANGELOG.md

@@ -5,6 +5,13 @@ Documentation of all notable changes to the **EVMC** project.
 The format is based on [Keep a Changelog],
 and this project adheres to [Semantic Versioning].
 
+## [7.0.0] - unreleased
+
+### Added
+
+- Support for Istanbul CHAINID opcode. `chain_id` added to `evmc_tx_context` struct.
+  [[#375](https://github.com/ethereum/evmc/pull/375)]
+
 ## [6.3.1] - 2019-08-19
 
 ### Added
@@ -340,6 +347,7 @@ and this project adheres to [Semantic Versioning].
   [[#52](https://github.com/ethereum/evmc/pull/52)]
 
 
+[7.0.0]: https://github.com/ethereum/evmc/compare/v6.3.1...master
 [6.3.1]: https://github.com/ethereum/evmc/releases/tag/v6.3.1
 [6.3.0]: https://github.com/ethereum/evmc/releases/tag/v6.3.0
 [6.2.2]: https://github.com/ethereum/evmc/releases/tag/v6.2.2

bindings/go/evmc/host.go

@@ -77,6 +77,7 @@ type TxContext struct {
 	Timestamp  int64
 	GasLimit   int64
 	Difficulty common.Hash
+	ChainID    common.Hash
 }
 
 type HostContext interface {
@@ -181,6 +182,7 @@ func getTxContext(pCtx unsafe.Pointer) C.struct_evmc_tx_context {
 		C.int64_t(txContext.Timestamp),
 		C.int64_t(txContext.GasLimit),
 		evmcBytes32(txContext.Difficulty),
+		evmcBytes32(txContext.ChainID),
 	}
 }
 

bindings/rust/evmc-vm/src/container.rs

@@ -85,6 +85,7 @@ mod tests {
             block_timestamp: 0,
             block_gas_limit: 0,
             block_difficulty: Uint256::default(),
+            chain_id: Uint256::default(),
         }
     }
 

bindings/rust/evmc-vm/src/lib.rs

@@ -759,6 +759,7 @@ mod tests {
             block_timestamp: 235117,
             block_gas_limit: 105023,
             block_difficulty: Uint256 { bytes: [0xaa; 32] },
+            chain_id: Uint256::default(),
         }
     }
 

include/evmc/evmc.h

@@ -153,6 +153,7 @@ struct evmc_tx_context
     int64_t block_timestamp;         /**< The block timestamp. */
     int64_t block_gas_limit;         /**< The block gas limit. */
     evmc_uint256be block_difficulty; /**< The block difficulty. */
+    evmc_uint256be chain_id;         /**< The blockchain's ChainID. */
 };
 
 struct evmc_context;

include/evmc/evmc.hpp

@@ -640,8 +640,7 @@ inline void emit_log(evmc_context* h,
 
 constexpr evmc_host_interface interface{
     account_exists, get_storage,  set_storage, get_balance,    get_code_size,  get_code_hash,
-    copy_code,      selfdestruct, call,        get_tx_context, get_block_hash, emit_log,
-};
+    copy_code,      selfdestruct, call,        get_tx_context, get_block_hash, emit_log};
 }  // namespace internal
 
 inline Host::Host() noexcept : evmc_context{&evmc::internal::interface} {}

include/evmc/instructions.h

@@ -78,6 +78,7 @@ enum evmc_opcode
     OP_NUMBER = 0x43,
     OP_DIFFICULTY = 0x44,
     OP_GASLIMIT = 0x45,
+    OP_CHAINID = 0x46,
 
     OP_POP = 0x50,
     OP_MLOAD = 0x51,

lib/instructions/instruction_metrics.c

@@ -92,7 +92,7 @@ static struct evmc_instruction_metrics istanbul_metrics[256] = {
     /*         NUMBER = 0x43 */ {BASE, 0, 1},
     /*     DIFFICULTY = 0x44 */ {BASE, 0, 1},
     /*       GASLIMIT = 0x45 */ {BASE, 0, 1},
-    /*                = 0x46 */ {UNDEFINED, 0, 0},
+    /*       CHAINID  = 0x46 */ {BASE, 0, 1},
     /*                = 0x47 */ {UNDEFINED, 0, 0},
     /*                = 0x48 */ {UNDEFINED, 0, 0},
     /*                = 0x49 */ {UNDEFINED, 0, 0},

lib/instructions/instruction_names.c

@@ -76,7 +76,7 @@ static const char* istanbul_names[256] = {
     /* 0x43 */ "NUMBER",
     /* 0x44 */ "DIFFICULTY",
     /* 0x45 */ "GASLIMIT",
-    /* 0x46 */ NULL,
+    /* 0x46 */ "CHAINID",
     /* 0x47 */ NULL,
     /* 0x48 */ NULL,
     /* 0x49 */ NULL,

test/unittests/test_instructions.cpp

@@ -251,7 +251,21 @@ TEST(instructions, istanbul_hard_fork)
 
     for (int op{OP_STOP}; op <= OP_SELFDESTRUCT; ++op)
     {
-        EXPECT_EQ(i[op], p[op]) << op;
-        EXPECT_STREQ(in[op], pn[op]) << op;
+        switch (op)
+        {
+        case OP_CHAINID:
+            continue;
+        default:
+            EXPECT_EQ(i[op], p[op]) << op;
+            EXPECT_STREQ(in[op], pn[op]) << op;
+            break;
+        }
     }
+
+    EXPECT_EQ(i[OP_CHAINID].gas_cost, 2);
+    EXPECT_EQ(i[OP_CHAINID].num_stack_arguments, 0);
+    EXPECT_EQ(i[OP_CHAINID].num_stack_returned_items, 1);
+    EXPECT_EQ(p[OP_CHAINID].gas_cost, -1);
+    EXPECT_EQ(in[OP_CHAINID], std::string{"CHAINID"});
+    EXPECT_TRUE(pn[OP_CHAINID] == nullptr);
 }