ACT.CDT is a toolchain for WebAssembly (WASM) and set of tools to facilitate contract writing for the Achain platform. In addition to being a general purpose WebAssembly toolchain, Achain specific optimizations are available to support building Achain smart contracts. This new toolchain is built around Clang 7, which means that act.CDT has the most currently available optimizations and analyses from LLVM, but as the WASM target is still considered experimental, some optimizations are not available or incomplete.
ACT.CDT currently supports Linux x86_64 RPM / Debian packages.
$ wget https://github.com/Achain-Dev/act.cdt/releases/download/v1.0.0/act.cdt-1.0.0-1.x86_64.rpm
$ sudo yum install ./act.cdt-1.0.0-1.x86_64.rpm$ sudo yum remove act.cdt$ wget https://github.com/Achain-Dev/act.cdt/releases/download/v1.0.0/act.cdt_1.0.0-1_amd64.deb
$ sudo apt install ./act.cdt_1.0.0-1_amd64.deb$ sudo apt remove act.cdt$ git clone --recursive https://github.com/Achain-Dev/act.cdt.git
$ cd act.cdt
$ ./build.sh
$ sudo ./install.sh- Navigate to the hello folder in examples (./examples/hello).
- You should then see the hello.cpp file
- Now run the compiler
$ eosio-cpp -abigen hello.cpp -o hello.wasm- Or with CMake
$ mkdir build
$ cd build
$ cmake ..
$ makeThis will generate two files:
- The compiled binary wasm (hello.wasm)
- The generated ABI file (hello.abi)
To generate an ABI with eosio-abigen, only requires that you give the main '.cpp' file to compile and the output filename --output and generating against the contract name --contract.
Example:
$ eosio-abigen hello.cpp --contract=hello --output=hello.abiThis will generate one file:
- The generated ABI file (hello.abi)
Unlike the old ABI generator tool, the new tool uses C++11 or GNU style attributes to mark actions and tables.
This attribute marks either a struct or a method as an action. Example (four ways to declare an action for ABI generation):
// this is the C++11 and greater style attribute
[[eosio::action]]
void testa( name n ) {
// do something
}
// this is the GNU style attribute, this can be used in C code and prior to C++ 11
__attribute__((eosio_action))
void testa( name n ){
// do something
}
struct [[eosio::action]] testa {
name n;
EOSLIB_SERIALIZE( testa, (n) )
};
struct __attribute__((eosio_action)) testa {
name n;
EOSLIB_SERIALIZE( testa, (n) )
};If your action name is not a valid EOSIO name you can explicitly specify the name in the attribute c++ [[eosio::action("<valid action name>")]]
Example (two ways to declare a table for ABI generation):
struct [[eosio::table]] testtable {
uint64_t owner;
/* all other fields */
};
struct __attribute__((eosio_table)) testtable {
uint64_t owner;
/* all other fields */
};
typedef eosio::multi_index<"tablename"_n, testtable> testtable_t;If you don't want to use the multi-index you can explicitly specify the name in the attribute c++ [[eosio::table("<valid action name>")]].
For an example contract of ABI generation please see the file ./examples/abigen_test/test.cpp. You can generate the ABI for this file with eosio-abigen test.cpp --output=test.abi.
- The sections to the ABI are pretty simple to understand and the syntax is purely JSON, so it is reasonable to write an ABI file manually.
- The ABI generation will never be completely perfect for every contract written. Advanced features of the newest version of the ABI will require manual construction of the ABI, and odd and advanced C++ patterns could capsize the generators type deductions. So having a good knowledge of how to write an ABI should be an essential piece of knowledge of a smart contract writer.
- Please refer to developers.eos.io "How to Write an ABI File" to learn about the different sections of an ABI.
- As of ACTX.CDT v1.4.0 the ABI generator will try to automatically import contracts and clauses into the generated ABI. There are a few caveats to this, one is a strict naming policy of the files and an HTML tag used to mark each Ricardian contract and each clause.
- The Ricardian contracts should be housed in a file with the name .contracts.md and the clauses should be in a file named .clauses.md.
- For each Ricardian contract the header
<h1 class="contract">ActionName</h1>should be used, as this directs the ABI generator to attach this Ricardian contract to the specified action. - For each Ricardian clause the header
<h1 class="clause">ClauseID</h1>should be used, as this directs the ABI generator to the clause id and the subsequent body. - The option
-Rhas been added to eosio-cpp and eosio-abigen to add "resource" paths to search from, so you can place these files in any directory structure you like and use-R<path to file>in the same vein as-Ifor include paths. - To see these in use please see ./examples/hello/hello.contracts.md and ./examples/hello/hello.clauses.md.
- eosio-cpp
- eosio-cc
- eosio-ld
- eosio-abigen
- eosio-pp (post processing pass for WASM, automatically runs with eosio-cpp and eosio-ld)
- eosio-wasm2wast
- eosio-wast2wasm
- eosio-ranlib
- eosio-ar
- eosio-objdump
- eosio-readelf
To compile an ACHAIN smart contract, the preferred method is to use the template CMakeLists.txt in the examples folder.
For example:
In CMakeLists.txt:
cmake_minimum_required(VERSION 3.5)
project(test_example VERSION 1.0.0)
find_package(actx.cdt)
add_contract( test test test.cpp )
In test.cpp:
#include <eosiolib/eosio.hpp>
using namespace eosio;
CONTRACT test : public eosio::contract {
public:
using contract::contract;
ACTION testact( name test ) {
}
};
EOSIO_DISPATCH( test, (testact) )
To manually compile the source code, use eosio-cpp/eosio-cc and eosio-ld as if it were clang and lld. All the includes and options specific to ACHAIN and CDT are baked in.
OVERVIEW: eosio-cpp (Eosio C++ -> WebAssembly compiler)
USAGE: eosio-cpp [options] <input file> ...
OPTIONS:
-C - Include comments in preprocessed output
-CC - Include comments from within macros in preprocessed output
-D=<string> - Define <macro> to <value> (or 1 if <value> omitted)
-E - Only run the preprocessor
-I=<string> - Add directory to include search path
-L=<string> - Add directory to library search path
-O=<string> - Optimization level s, 0-3
-S - Only run preprocess and compilation steps
-U=<string> - Undefine macro <macro>
-W=<string> - Enable the specified warning
-c - Only run preprocess, compile, and assemble steps
-dD - Print macro definitions in -E mode in addition to normal output
-dI - Print include directives in -E mode in addition to normal outpu
-dM - Print macro definitions in -E mode instead to normal output
-emit-ast - Emit Clang AST files for source inputs
-emit-llvm - Use the LLVM representation for assembler and object files
-faligned-allocation - Enable C++17 aligned allocation functions
-fcoroutine-ts - Enable support for the C++ Coroutines TS
-finline-functions - Inline suitable functions
-finline-hint-functions - Inline functions which are (explicitly or implicitly) marked inline
-fmerge-all-constants - Allow merging of constants
-fno-cfl-aa - Disable CFL Alias Analysis
-fno-elide-constructors - Disable C++ copy constructor elision
-fno-lto - Disable LTO
-fstack-protector - Enable stack protectors for functions potentially vulnerable to stack smashing
-fstack-protector-all - Force the usage of stack protectors for all functions
-fstack-protector-strong - Use a strong heuristic to apply stack protectors to functions
-fstrict-enums - Enable optimizations based on the strict definition of an enum's value range
-fstrict-return - Always treat control flow paths that fall off the end of a non-void function as unreachable
-fstrict-vtable-pointers - Enable optimizations based on the strict rules for overwriting polymorphic C++ objects
-include=<string> - Include file before parsing
-isysroot=<string> - Set the system root directory (usually /)
-l=<string> - Root name of library to link
-lto-opt=<string> - LTO Optimization level (O0-O3)
-o=<string> - Write output to <file>
-std=<string> - Language standard to compile for
-v - Show commands to run and use verbose output
-w - Suppress all warnings
Generic Options:
-help - Display available options (-help-hidden for more)
-help-list - Display list of available options (-help-list-hidden for more)
-version - Display the version of this programOVERVIEW: eosio-ld (WebAssembly linker)
USAGE: eosio-ld [options] <input file> ...
OPTIONS:
Generic Options:
-help - Display available options (-help-hidden for more)
-help-list - Display list of available options (-help-list-hidden for more)
-version - Display the version of this program
eosio.ld options:
-L=<string> - Add directory to library search path
-fno-cfl-aa - Disable CFL Alias Analysis
-fno-lto - Disable LTO
-fno-post-pass - Don't run post processing pass
-fno-stack-first - Don't set the stack first in memory
-l=<string> - Root name of library to link
-lto-opt=<string> - LTO Optimization level (O0-O3)
-o=<string> - Write output to <file>USAGE: eosio-abigen [options] <source0> [... <sourceN>]
OPTIONS:
Generic Options:
-help - Display available options (-help-hidden for more)
-help-list - Display list of available options (-help-list-hidden for more)
-version - Display the version of this program
eosio-abigen:
generates an ABI from C++ project input
-extra-arg=<string> - Additional argument to append to the compiler command line
-extra-arg-before=<string> - Additional argument to prepend to the compiler command line
-output=<string> - Set the output filename and fullpath
-p=<string> - Build pathMIT