2019-01-25 hera在windows下的编译

hera工程在linux下比较好编译，但是在windows下如果使用cmake生成vc的工程编译就各种错误，因此采用cygwin来编译

1、去除cmake，make的环境变量

由于开始为了在vc下编译，分别下载了cmake-3.13.3-win64-x64.msi 和 gnuwin32
去除path里面的：
C:\Program Files\CMake\bin
C:\Program Files (x86)\GnuWin32\bin
因为这些如果存在，cmake出来的一定还是vc版本

2、安装cygwin

参考文章 如何在Windows中编译Linux Unix的代码（采用cygwin）
这里有几个错误，

2.1、设置163镜像的地址不对，应该是：http://mirrors.163.com/cygwin/

2.2、库名称有点问题

Devel 选项下的gcc-core,gcc-g++,make 以及Lib选项卡下的libglib2,libglib2-devel

2.3 另外需要安装的库

增加安装cmake

3、下载编译hera

启动cygwin，执行

cd /cygdrive/d/temp/
git clone https://github.com/ewasm/hera
cd hera
git submodule update --init

mkdir build
cd build
cmake ..
make

如果出现下面的错误：

CMake Error at CMakeLists.txt:1 (cmake_minimum_required):
  CMake 3.8 or higher is required.  You are running version 3.6.2

需要升级cygwin的cmake版本，否则后续代码编译会出错
编译成功后会在build\src\生成文件cyghera.dll

4、调用测试

4.1、修改hera\evmc\examples\CMakeLists.txt

内容为：

# EVMC: Ethereum Client-VM Connector API.
# Copyright 2018 The EVMC Authors.
# Licensed under the Apache License, Version 2.0. See the LICENSE file.
cmake_minimum_required(VERSION 3.8)

include(GNUInstallDirs)

if(NOT CMAKE_CXX_STANDARD)
    set(CMAKE_CXX_STANDARD 11)
    set(CMAKE_CXX_EXTENSIONS OFF)
endif()
set(CMAKE_DEBUG_POSTFIX "")

include_directories(../include
../../include
)

add_library(evmc-example-host STATIC example_host.cpp)
target_link_libraries(evmc-example-host PRIVATE)


add_library(evmc-example-vm example_vm.c)
target_link_libraries(evmc-example-vm PRIVATE)
set_source_files_properties(example_vm.c PROPERTIES COMPILE_DEFINITIONS PROJECT_VERSION=${PROJECT_VERSION})


#add_executable(evmc-example example.c)
#target_link_libraries(evmc-example PRIVATE evmc-example-host evmc-example-vm)

add_executable(evmc-example example.c loader.c)
target_link_libraries(evmc-example PRIVATE evmc-example-host evmc-example-vm)

install(TARGETS evmc-example-vm
    ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
)

4.2、复制loader.c

cd /cygdrive/d/temp/hera/evmc/examples
cp ../lib/loader/loader.c .

4.3、修改example.c

/* EVMC: Ethereum Client-VM Connector API.
 * Copyright 2018 The EVMC Authors.
 * Licensed under the Apache License, Version 2.0. See the LICENSE file.
 */

#include "example_host.h"
#include "example_vm.h"

#include <evmc/helpers.h>

#include <inttypes.h>
#include <stdio.h>
#include <string.h>
#include <evmc/loader.h>

int main()
{
      enum evmc_loader_error_code ec;
    evmc_create_fn create_fn = evmc_load("libhera.dll", &ec);
    if(ec != EVMC_LOADER_SUCCESS) 
    {
        printf("load libhera.dll error,err=%d",ec);
    }

    struct evmc_instance* vm = create_fn();
    if (!evmc_is_abi_compatible(vm))
        return 1;
    // EVM bytecode goes here. This is one of the examples.
    const uint8_t code[] = "\x30\x60\x00\x52\x59\x60\x00\xf3";
    const size_t code_size = strlen((char*)code);
    const uint8_t input[] = "Hello World!";
    const evmc_uint256be value = {{1, 0}};
    const evmc_address addr = {{0, 1, 2}};
    const int64_t gas = 200000;
    struct evmc_context* ctx = example_host_create_context();
    struct evmc_message msg;
    msg.sender = addr;
    msg.destination = addr;
    msg.value = value;
    msg.input_data = input;
    msg.input_size = sizeof(input);
    msg.gas = gas;
    msg.depth = 0;
    struct evmc_result result = evmc_execute(vm, ctx, EVMC_HOMESTEAD, &msg, code, code_size);
    printf("Execution result:\n");
    if (result.status_code != EVMC_SUCCESS)
    {
        printf("  EVM execution failure: %d\n", result.status_code);
    }
    else
    {
        printf("  Gas used: %" PRId64 "\n", gas - result.gas_left);
        printf("  Gas left: %" PRId64 "\n", result.gas_left);
        printf("  Output size: %zd\n", result.output_size);
        printf("  Output: ");
        size_t i = 0;
        for (i = 0; i < result.output_size; i++)
            printf("%02x ", result.output_data[i]);
        printf("\n");
    }
    evmc_release_result(&result);
    example_host_destroy_context(ctx);
    evmc_destroy(vm);
    return 0;
}

4.4、编译

mkdir build
cd build
cmake ..
make

4.5、复制cyghera.dll，并改名

cp ../../../build/src/cyghera.dll libhera.dll

4.6、执行

 ./evmc-example.exe
Executing message in Hera
InternalError: Only Byzantium supported.
Execution result:
  EVM execution failure: -1
Segmentation fault (核心已转储)

目前存在的问题：
java调用这个dll一定crash，依赖的dll都能够找到，但是加载失败