Merge pull request #313 from ethereum/execute_api

Provide better execute() C++ API

Author: chfast

lib/evmone/analysis.hpp

@@ -55,14 +55,7 @@ struct AdvancedExecutionState : ExecutionState
     /// Pointer to code analysis.
     const AdvancedCodeAnalysis* analysis = nullptr;
 
-    AdvancedExecutionState() = default;
-
-    AdvancedExecutionState(const evmc_message& message, evmc_revision revision,
-        const evmc_host_interface& host_interface, evmc_host_context* host_ctx,
-        const uint8_t* code_ptr, size_t code_size, const AdvancedCodeAnalysis& a) noexcept
-      : ExecutionState{message, revision, host_interface, host_ctx, code_ptr, code_size},
-        analysis{&a}
-    {}
+    using ExecutionState::ExecutionState;
 
     /// Terminates the execution with the given status code.
     const instruction* exit(evmc_status_code status_code) noexcept
@@ -74,11 +67,11 @@ struct AdvancedExecutionState : ExecutionState
     /// Resets the contents of the execution_state so that it could be reused.
     void reset(const evmc_message& message, evmc_revision revision,
         const evmc_host_interface& host_interface, evmc_host_context* host_ctx,
-        const uint8_t* code_ptr, size_t code_size, const AdvancedCodeAnalysis& a) noexcept
+        const uint8_t* code_ptr, size_t code_size) noexcept
     {
         ExecutionState::reset(message, revision, host_interface, host_ctx, code_ptr, code_size);
         current_block_cost = 0;
-        analysis = &a;
+        analysis = nullptr;
     }
 };
 

lib/evmone/execution.cpp

@@ -8,22 +8,26 @@
 
 namespace evmone
 {
-evmc_result execute(evmc_vm* /*unused*/, const evmc_host_interface* host, evmc_host_context* ctx,
-    evmc_revision rev, const evmc_message* msg, const uint8_t* code, size_t code_size) noexcept
+evmc_result execute(AdvancedExecutionState& state, const AdvancedCodeAnalysis& analysis) noexcept
 {
-    const auto analysis = analyze(rev, code, code_size);
+    state.analysis = &analysis;  // Allow accessing the analysis by instructions.
 
-    auto state =
-        std::make_unique<AdvancedExecutionState>(*msg, rev, *host, ctx, code, code_size, analysis);
-
-    const auto* instr = &state->analysis->instrs[0];
+    const auto* instr = &state.analysis->instrs[0];  // Start with the first instruction.
     while (instr != nullptr)
-        instr = instr->fn(instr, *state);
+        instr = instr->fn(instr, state);
 
     const auto gas_left =
-        (state->status == EVMC_SUCCESS || state->status == EVMC_REVERT) ? state->gas_left : 0;
+        (state.status == EVMC_SUCCESS || state.status == EVMC_REVERT) ? state.gas_left : 0;
 
     return evmc::make_result(
-        state->status, gas_left, &state->memory[state->output_offset], state->output_size);
+        state.status, gas_left, &state.memory[state.output_offset], state.output_size);
+}
+
+evmc_result execute(evmc_vm* /*unused*/, const evmc_host_interface* host, evmc_host_context* ctx,
+    evmc_revision rev, const evmc_message* msg, const uint8_t* code, size_t code_size) noexcept
+{
+    const auto analysis = analyze(rev, code, code_size);
+    auto state = std::make_unique<AdvancedExecutionState>(*msg, rev, *host, ctx, code, code_size);
+    return execute(*state, analysis);
 }
 }  // namespace evmone

lib/evmone/execution.hpp

@@ -7,6 +7,13 @@
 
 namespace evmone
 {
+struct AdvancedExecutionState;
+struct AdvancedCodeAnalysis;
+
+/// Execute the already analyzed code using the provided execution state.
+evmc_result execute(AdvancedExecutionState& state, const AdvancedCodeAnalysis& analysis) noexcept;
+
+/// EVMC-compatible execute() function.
 evmc_result execute(evmc_vm* vm, const evmc_host_interface* host, evmc_host_context* ctx,
     evmc_revision rev, const evmc_message* msg, const uint8_t* code, size_t code_size) noexcept;
 }  // namespace evmone

test/unittests/execution_state_test.cpp

@@ -117,10 +117,8 @@ TEST(execution_state, reset_advanced)
         msg2.gas = 13;
         const evmc_host_interface host_interface2{};
         const uint8_t code2[]{0x80, 0x81};
-        evmone::AdvancedCodeAnalysis analysis2;
 
-        st.reset(
-            msg2, EVMC_HOMESTEAD, host_interface2, nullptr, code2, std::size(code2), analysis2);
+        st.reset(msg2, EVMC_HOMESTEAD, host_interface2, nullptr, code2, std::size(code2));
 
         // TODO: We are not able to test HostContext with current API. It may require an execution
         //       test.
@@ -136,7 +134,7 @@ TEST(execution_state, reset_advanced)
         EXPECT_EQ(st.output_offset, 0);
         EXPECT_EQ(st.output_size, 0);
         EXPECT_EQ(st.current_block_cost, 0u);
-        EXPECT_EQ(st.analysis, &analysis2);
+        EXPECT_EQ(st.analysis, nullptr);
     }
 }