solidity compiler and contract metadocs integration

* common/compiler: solidity compiler + tests
* rpc: eth_compilers, eth_compileSolidity + tests
* fix natspec test using keystore API, notice exp dynamically changes addr, cleanup
* resolver implements registrars and needs to create reg contract (temp)
* xeth: solidity compiler. expose getter Solc() and paths setter SetSolc(solcPath)
* ethereumApi: implement compiler related RPC calls using XEth - json struct tests
* admin: make use of XEth.SetSolc to allow runtime setting of compiler paths
* cli: command line flags solc to set custom solc bin path
* js admin api with new features debug and contractInfo modules
* wiki is the doc https://github.com/ethereum/go-ethereum/wiki/Contracts-and-Transactions

common/compiler/solidity.go

@@ -0,0 +1,187 @@
+package compiler
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path"
+	"path/filepath"
+	"regexp"
+	"strings"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/logger"
+	"github.com/ethereum/go-ethereum/logger/glog"
+)
+
+const (
+	flair           = "Christian <c@ethdev.com> and Lefteris <lefteris@ethdev.com> (c) 2014-2015"
+	languageVersion = "0"
+)
+
+var (
+	versionRegExp = regexp.MustCompile("[0-9]+.[0-9]+.[0-9]+")
+	params        = []string{
+		"--binary",       // Request to output the contract in binary (hexadecimal).
+		"file",           //
+		"--json-abi",     // Request to output the contract's JSON ABI interface.
+		"file",           //
+		"--natspec-user", // Request to output the contract's Natspec user documentation.
+		"file",           //
+		"--natspec-dev",  // Request to output the contract's Natspec developer documentation.
+		"file",
+	}
+)
+
+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"`
+	AbiDefinition   interface{} `json:"abiDefinition"`
+	UserDoc         interface{} `json:"userDoc"`
+	DeveloperDoc    interface{} `json:"developerDoc"`
+}
+
+type Solidity struct {
+	solcPath string
+	version  string
+}
+
+func New(solcPath string) (sol *Solidity, err error) {
+	// set default solc
+	if len(solcPath) == 0 {
+		solcPath = "solc"
+	}
+	solcPath, err = exec.LookPath(solcPath)
+	if err != nil {
+		return
+	}
+
+	cmd := exec.Command(solcPath, "--version")
+	var out bytes.Buffer
+	cmd.Stdout = &out
+	err = cmd.Run()
+	if err != nil {
+		return
+	}
+
+	version := versionRegExp.FindString(out.String())
+	sol = &Solidity{
+		solcPath: solcPath,
+		version:  version,
+	}
+	glog.V(logger.Info).Infoln(sol.Info())
+	return
+}
+
+func (sol *Solidity) Info() string {
+	return fmt.Sprintf("solc v%s\nSolidity Compiler: %s\n%s", sol.version, sol.solcPath, flair)
+}
+
+func (sol *Solidity) Compile(source string) (contract *Contract, err error) {
+
+	if len(source) == 0 {
+		err = fmt.Errorf("empty source")
+		return
+	}
+
+	wd, err := ioutil.TempDir("", "solc")
+	if err != nil {
+		return
+	}
+	defer os.RemoveAll(wd)
+
+	in := strings.NewReader(source)
+	var out bytes.Buffer
+	// cwd set to temp dir
+	cmd := exec.Command(sol.solcPath, params...)
+	cmd.Dir = wd
+	cmd.Stdin = in
+	cmd.Stdout = &out
+	err = cmd.Run()
+	if err != nil {
+		err = fmt.Errorf("solc error: %v", err)
+		return
+	}
+
+	matches, _ := filepath.Glob(wd + "/*.binary")
+	if len(matches) < 1 {
+		err = fmt.Errorf("solc error: missing code output")
+		return
+	}
+	if len(matches) > 1 {
+		err = fmt.Errorf("multi-contract sources are not supported")
+		return
+	}
+	_, file := filepath.Split(matches[0])
+	base := strings.Split(file, ".")[0]
+
+	codeFile := path.Join(wd, base+".binary")
+	abiDefinitionFile := path.Join(wd, base+".abi")
+	userDocFile := path.Join(wd, base+".docuser")
+	developerDocFile := path.Join(wd, base+".docdev")
+
+	code, err := ioutil.ReadFile(codeFile)
+	if err != nil {
+		err = fmt.Errorf("error reading compiler output for code: %v", err)
+		return
+	}
+	abiDefinitionJson, err := ioutil.ReadFile(abiDefinitionFile)
+	if err != nil {
+		err = fmt.Errorf("error reading compiler output for abiDefinition: %v", err)
+		return
+	}
+	var abiDefinition interface{}
+	err = json.Unmarshal(abiDefinitionJson, &abiDefinition)
+
+	userDocJson, err := ioutil.ReadFile(userDocFile)
+	if err != nil {
+		err = fmt.Errorf("error reading compiler output for userDoc: %v", err)
+		return
+	}
+	var userDoc interface{}
+	err = json.Unmarshal(userDocJson, &userDoc)
+
+	developerDocJson, err := ioutil.ReadFile(developerDocFile)
+	if err != nil {
+		err = fmt.Errorf("error reading compiler output for developerDoc: %v", err)
+		return
+	}
+	var developerDoc interface{}
+	err = json.Unmarshal(developerDocJson, &developerDoc)
+
+	contract = &Contract{
+		Code: string(code),
+		Info: ContractInfo{
+			Source:          source,
+			Language:        "Solidity",
+			LanguageVersion: languageVersion,
+			CompilerVersion: sol.version,
+			AbiDefinition:   abiDefinition,
+			UserDoc:         userDoc,
+			DeveloperDoc:    developerDoc,
+		},
+	}
+
+	return
+}
+
+func ExtractInfo(contract *Contract, filename string) (contenthash common.Hash, err error) {
+	contractInfo, err := json.Marshal(contract.Info)
+	if err != nil {
+		return
+	}
+	contenthash = common.BytesToHash(crypto.Sha3(contractInfo))
+	err = ioutil.WriteFile(filename, contractInfo, 0600)
+	return
+}