path: root/common/compiler/solidity.go

// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

// Package compiler wraps the Solidity compiler executable (solc).
package compiler

import (
    "bytes"
    "encoding/json"
    "errors"
    "fmt"
    "io/ioutil"
    "os/exec"
    "regexp"
    "strconv"
    "strings"
)

var versionRegexp = regexp.MustCompile(`([0-9]+)\.([0-9]+)\.([0-9]+)`)

type Contract struct {
    Code string       `json:"code"`
    Info ContractInfo `json:"info"`
}

type ContractInfo struct {
    Source          string      `json:"source"`
    Language        string      `json:"language"`
    LanguageVersion string      `json:"languageVersion"`
    CompilerVersion string      `json:"compilerVersion"`
    CompilerOptions string      `json:"compilerOptions"`
    AbiDefinition   interface{} `json:"abiDefinition"`
    UserDoc         interface{} `json:"userDoc"`
    DeveloperDoc    interface{} `json:"developerDoc"`
    Metadata        string      `json:"metadata"`
}

// Solidity contains information about the solidity compiler.
type Solidity struct {
    Path, Version, FullVersion string
    Major, Minor, Patch        int
}

// --combined-output format
type solcOutput struct {
    Contracts map[string]struct {
        Bin, Abi, Devdoc, Userdoc, Metadata string
    }
    Version string
}

func (s *Solidity) makeArgs() []string {
    p := []string{
        "--combined-json", "bin,abi,userdoc,devdoc",
        "--add-std",  // include standard lib contracts
        "--optimize", // code optimizer switched on
    }
    if s.Major > 0 || s.Minor > 4 || s.Patch > 6 {
        p[1] += ",metadata"
    }
    return p
}

// SolidityVersion runs solc and parses its version output.
func SolidityVersion(solc string) (*Solidity, error) {
    if solc == "" {
        solc = "solc"
    }
    var out bytes.Buffer
    cmd := exec.Command(solc, "--version")
    cmd.Stdout = &out
    err := cmd.Run()
    if err != nil {
        return nil, err
    }
    matches := versionRegexp.FindStringSubmatch(out.String())
    if len(matches) != 4 {
        return nil, fmt.Errorf("can't parse solc version %q", out.String())
    }
    s := &Solidity{Path: cmd.Path, FullVersion: out.String(), Version: matches[0]}
    if s.Major, err = strconv.Atoi(matches[1]); err != nil {
        return nil, err
    }
    if s.Minor, err = strconv.Atoi(matches[2]); err != nil {
        return nil, err
    }
    if s.Patch, err = strconv.Atoi(matches[3]); err != nil {
        return nil, err
    }
    return s, nil
}

// CompileSolidityString builds and returns all the contracts contained within a source string.
func CompileSolidityString(solc, source string) (map[string]*Contract, error) {
    if len(source) == 0 {
        return nil, errors.New("solc: empty source string")
    }
    s, err := SolidityVersion(solc)
    if err != nil {
        return nil, err
    }
    args := append(s.makeArgs(), "--")
    cmd := exec.Command(s.Path, append(args, "-")...)
    cmd.Stdin = strings.NewReader(source)
    return s.run(cmd, source)
}

// CompileSolidity compiles all given Solidity source files.
func CompileSolidity(solc string, sourcefiles ...string) (map[string]*Contract, error) {
    if len(sourcefiles) == 0 {
        return nil, errors.New("solc: no source files")
    }
    source, err := slurpFiles(sourcefiles)
    if err != nil {
        return nil, err
    }
    s, err := SolidityVersion(solc)
    if err != nil {
        return nil, err
    }
    args := append(s.makeArgs(), "--")
    cmd := exec.Command(s.Path, append(args, sourcefiles...)...)
    return s.run(cmd, source)
}

func (s *Solidity) run(cmd *exec.Cmd, source string) (map[string]*Contract, error) {
    var stderr, stdout bytes.Buffer
    cmd.Stderr = &stderr
    cmd.Stdout = &stdout
    if err := cmd.Run(); err != nil {
        return nil, fmt.Errorf("solc: %v\n%s", err, stderr.Bytes())
    }
    var output solcOutput
    if err := json.Unmarshal(stdout.Bytes(), &output); err != nil {
        return nil, err
    }

    // Compilation succeeded, assemble and return the contracts.
    contracts := make(map[string]*Contract)
    for name, info := range output.Contracts {
        // Parse the individual compilation results.
        var abi interface{}
        if err := json.Unmarshal([]byte(info.Abi), &abi); err != nil {
            return nil, fmt.Errorf("solc: error reading abi definition (%v)", err)
        }
        var userdoc interface{}
        if err := json.Unmarshal([]byte(info.Userdoc), &userdoc); err != nil {
            return nil, fmt.Errorf("solc: error reading user doc: %v", err)
        }
        var devdoc interface{}
        if err := json.Unmarshal([]byte(info.Devdoc), &devdoc); err != nil {
            return nil, fmt.Errorf("solc: error reading dev doc: %v", err)
        }
        contracts[name] = &Contract{
            Code: "0x" + info.Bin,
            Info: ContractInfo{
                Source:          source,
                Language:        "Solidity",
                LanguageVersion: s.Version,
                CompilerVersion: s.Version,
                CompilerOptions: strings.Join(s.makeArgs(), " "),
                AbiDefinition:   abi,
                UserDoc:         userdoc,
                DeveloperDoc:    devdoc,
                Metadata:        info.Metadata,
            },
        }
    }
    return contracts, nil
}

func slurpFiles(files []string) (string, error) {
    var concat bytes.Buffer
    for _, file := range files {
        content, err := ioutil.ReadFile(file)
        if err != nil {
            return "", err
        }
        concat.Write(content)
    }
    return concat.String(), nil
}