Merge pull request #187 from ethereum/cpp

Add C++ wrappers/bindings for VM

examples/example_vm.c

@@ -1,6 +1,6 @@
 /* EVMC: Ethereum Client-VM Connector API.
- * Copyright 2018 The EVMC Authors.
+ * Copyright 2019 The EVMC Authors.
- * Licensed under the Apache License, Version 2.0. See the LICENSE file.
+ * Licensed under the Apache License, Version 2.0.
  */
 
 /// @file
@@ -158,6 +158,7 @@ static void set_tracer(struct evmc_instance* instance,
 
 /// Stringify the argument.
 #define STR(x) #x
+#define XSTR(x) STR(x)
 
 #if !defined(PROJECT_VERSION)
 /// The dummy project version if not provided by the build system.
@@ -171,7 +172,7 @@ struct evmc_instance* evmc_create_example_vm()
     struct evmc_instance init = {
         .abi_version = EVMC_ABI_VERSION,
         .name = "example_vm",
-        .version = STR(PROJECT_VERSION),
+        .version = XSTR(PROJECT_VERSION),
         .destroy = destroy,
         .execute = execute,
         .get_capabilities = get_capabilities,

examples/example_vm.h

@@ -8,7 +8,15 @@
 #include <evmc/evmc.h>
 #include <evmc/utils.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /**
  * Creates EVMC Example VM.
  */
 EVMC_EXPORT struct evmc_instance* evmc_create_example_vm(void);
+
+#ifdef __cplusplus
+}
+#endif

include/evmc/evmc.hpp

@@ -0,0 +1,79 @@
+/* EVMC: Ethereum Client-VM Connector API.
+ * Copyright 2019 The EVMC Authors.
+ * Licensed under the Apache License, Version 2.0.
+ */
+
+/// @file
+/// EVMC C++ API - wrappers and bindings for C++.
+
+#include <evmc/evmc.h>
+#include <evmc/helpers.h>
+
+#include <initializer_list>
+#include <utility>
+
+namespace evmc
+{
+class result : public evmc_result
+{
+public:
+    explicit result(evmc_result const& res) noexcept : evmc_result{res} {}
+
+    ~result() noexcept
+    {
+        if (release)
+            release(this);
+    }
+
+    result(result&& other) noexcept : evmc_result{other}
+    {
+        // Disable releaser of the rvalue object.
+        other.release = nullptr;
+    }
+
+    result(result const&) = delete;
+
+    result& operator=(result other) noexcept
+    {
+        std::swap(*this, other);
+        return *this;
+    }
+};
+
+class vm
+{
+public:
+    explicit vm(evmc_instance* instance) noexcept : m_instance{instance} {}
+    ~vm() noexcept { m_instance->destroy(m_instance); }
+
+    vm(evmc_instance* instance, std::initializer_list<std::pair<const char*, const char*>> options)
+      : m_instance{instance}
+    {
+        for (auto option : options)
+            set_option(option.first, option.second);
+    }
+
+    bool is_abi_compatible() const noexcept { return m_instance->abi_version == EVMC_ABI_VERSION; }
+
+    char const* name() const noexcept { return m_instance->name; }
+
+    char const* version() const noexcept { return m_instance->version; }
+
+    evmc_set_option_result set_option(const char name[], const char value[]) noexcept
+    {
+        return evmc_set_option(m_instance, name, value);
+    }
+
+    result execute(evmc_context& ctx,
+                   evmc_revision rev,
+                   const evmc_message& msg,
+                   const uint8_t* code,
+                   size_t code_size) noexcept
+    {
+        return result{m_instance->execute(m_instance, &ctx, rev, &msg, code, code_size)};
+    }
+
+private:
+    evmc_instance* const m_instance = nullptr;
+};
+}  // namespace evmc

lib/CMakeLists.txt

@@ -1,6 +1,6 @@
 # EVMC: Ethereum Client-VM Connector API.
-# Copyright 2018 The EVMC Authors.
+# Copyright 2019 The EVMC Authors.
-# Licensed under the Apache License, Version 2.0. See the LICENSE file.
+# Licensed under the Apache License, Version 2.0.
 
 add_subdirectory(instructions)
 add_subdirectory(loader)

test/unittests/CMakeLists.txt

@@ -39,11 +39,12 @@ add_custom_command(
 
 add_executable(
     evmc-test
+    test_cpp.cpp
     test_helpers.cpp
     test_instructions.cpp
     test_loader.cpp
 )
 
-target_link_libraries(evmc-test PRIVATE instructions loader GTest::gtest GTest::main)
+target_link_libraries(evmc-test PRIVATE evmc-example-vm instructions loader GTest::gtest GTest::main)
 set_target_properties(evmc-test PROPERTIES RUNTIME_OUTPUT_DIRECTORY ..)
 add_dependencies(evmc-test vm-mock)

test/unittests/test_cpp.cpp

@@ -0,0 +1,63 @@
+// EVMC: Ethereum Client-VM Connector API.
+// Copyright 2019 The EVMC Authors.
+// Licensed under the Apache License, Version 2.0.
+
+#include "../../examples/example_vm.h"
+
+#include <evmc/evmc.hpp>
+
+#include <gtest/gtest.h>
+
+#include <cstring>
+
+TEST(cpp, result)
+{
+    static int release_called = 0;
+    release_called = 0;
+
+    {
+        EXPECT_EQ(release_called, 0);
+        auto raw_result = evmc_result{};
+        raw_result.output_data = static_cast<uint8_t*>(std::malloc(13));
+        raw_result.release = [](const evmc_result* r) {
+            std::free(const_cast<uint8_t*>(r->output_data));
+            ++release_called;
+        };
+
+        auto res1 = evmc::result{raw_result};
+        auto res2 = std::move(res1);
+
+        EXPECT_EQ(release_called, 0);
+
+        [](evmc::result) {}(std::move(res2));
+
+        EXPECT_EQ(release_called, 1);
+    }
+    EXPECT_EQ(release_called, 1);
+}
+
+TEST(cpp, vm)
+{
+    auto vm = evmc::vm{evmc_create_example_vm()};
+    EXPECT_TRUE(vm.is_abi_compatible());
+
+    auto r = vm.set_option("verbose", "3");
+    EXPECT_EQ(r, EVMC_SET_OPTION_SUCCESS);
+
+    EXPECT_EQ(vm.name(), std::string{"example_vm"});
+    EXPECT_NE(vm.version()[0], 0);
+
+    auto ctx = evmc_context{};
+    auto res = vm.execute(ctx, EVMC_MAX_REVISION, {}, nullptr, 0);
+    EXPECT_EQ(res.status_code, EVMC_FAILURE);
+}
+
+TEST(cpp, vm_set_option)
+{
+    evmc_instance raw_instance = {EVMC_ABI_VERSION, "",      "",      nullptr,
+                                  nullptr,          nullptr, nullptr, nullptr};
+    raw_instance.destroy = [](evmc_instance*) {};
+
+    auto vm = evmc::vm{&raw_instance};
+    EXPECT_EQ(vm.set_option("1", "2"), EVMC_SET_OPTION_INVALID_NAME);
+}