595 lines
15 KiB
C++
595 lines
15 KiB
C++
#include <iostream>
|
||
#include <cstdlib>
|
||
|
||
#include <setjmp.h>
|
||
|
||
#include <readline/readline.h>
|
||
#include <readline/history.h>
|
||
|
||
#include "shared.hh"
|
||
#include "eval.hh"
|
||
#include "eval-inline.hh"
|
||
#include "store-api.hh"
|
||
#include "common-opts.hh"
|
||
#include "get-drvs.hh"
|
||
#include "derivations.hh"
|
||
#include "affinity.hh"
|
||
|
||
using namespace std;
|
||
using namespace nix;
|
||
|
||
|
||
string programId = "nix-repl";
|
||
|
||
|
||
struct NixRepl
|
||
{
|
||
string curDir;
|
||
EvalState state;
|
||
|
||
Strings loadedFiles;
|
||
|
||
const static int envSize = 32768;
|
||
StaticEnv staticEnv;
|
||
Env * env;
|
||
int displ;
|
||
StringSet varNames;
|
||
|
||
StringSet completions;
|
||
StringSet::iterator curCompletion;
|
||
|
||
NixRepl();
|
||
void mainLoop(const Strings & args);
|
||
void completePrefix(string prefix);
|
||
bool getLine(string & line);
|
||
bool processLine(string line);
|
||
void loadFile(const Path & path);
|
||
void initEnv();
|
||
void reloadFiles();
|
||
void addAttrsToScope(Value & attrs);
|
||
void addVarToScope(const Symbol & name, Value & v);
|
||
Expr * parseString(string s);
|
||
void evalString(string s, Value & v);
|
||
|
||
typedef set<Value *> ValuesSeen;
|
||
std::ostream & printValue(std::ostream & str, Value & v, unsigned int maxDepth);
|
||
std::ostream & printValue(std::ostream & str, Value & v, unsigned int maxDepth, ValuesSeen & seen);
|
||
};
|
||
|
||
|
||
void printHelp()
|
||
{
|
||
std::cout << "Usage: nix-repl\n";
|
||
}
|
||
|
||
|
||
string removeWhitespace(string s)
|
||
{
|
||
s = chomp(s);
|
||
size_t n = s.find_first_not_of(" \n\r\t");
|
||
if (n != string::npos) s = string(s, n);
|
||
return s;
|
||
}
|
||
|
||
|
||
NixRepl::NixRepl()
|
||
: staticEnv(false, &state.staticBaseEnv)
|
||
{
|
||
curDir = absPath(".");
|
||
|
||
store = openStore();
|
||
}
|
||
|
||
|
||
void NixRepl::mainLoop(const Strings & args)
|
||
{
|
||
std::cout << "Welcome to Nix version " << NIX_VERSION << ". Type :? for help." << std::endl << std::endl;
|
||
|
||
foreach (Strings::const_iterator, i, args)
|
||
loadedFiles.push_back(*i);
|
||
|
||
reloadFiles();
|
||
if (!loadedFiles.empty()) std::cout << std::endl;
|
||
|
||
using_history();
|
||
read_history(0);
|
||
|
||
while (true) {
|
||
string line;
|
||
if (!getLine(line)) {
|
||
std::cout << std::endl;
|
||
break;
|
||
}
|
||
|
||
try {
|
||
if (!processLine(removeWhitespace(line))) return;
|
||
} catch (Error & e) {
|
||
printMsg(lvlError, "error: " + e.msg());
|
||
} catch (Interrupted & e) {
|
||
printMsg(lvlError, "error: " + e.msg());
|
||
}
|
||
|
||
std::cout << std::endl;
|
||
}
|
||
}
|
||
|
||
|
||
/* Apparently, the only way to get readline() to return on Ctrl-C
|
||
(SIGINT) is to use siglongjmp(). That's fucked up... */
|
||
static sigjmp_buf sigintJmpBuf;
|
||
|
||
|
||
static void sigintHandler(int signo)
|
||
{
|
||
siglongjmp(sigintJmpBuf, 1);
|
||
}
|
||
|
||
|
||
/* Oh, if only g++ had nested functions... */
|
||
NixRepl * curRepl;
|
||
|
||
char * completerThunk(const char * s, int state)
|
||
{
|
||
string prefix(s);
|
||
|
||
/* If the prefix has a slash in it, use readline's builtin filename
|
||
completer. */
|
||
if (prefix.find('/') != string::npos)
|
||
return rl_filename_completion_function(s, state);
|
||
|
||
/* Otherwise, return all symbols that start with the prefix. */
|
||
if (state == 0) {
|
||
curRepl->completePrefix(s);
|
||
curRepl->curCompletion = curRepl->completions.begin();
|
||
}
|
||
if (curRepl->curCompletion == curRepl->completions.end()) return 0;
|
||
return strdup((curRepl->curCompletion++)->c_str());
|
||
}
|
||
|
||
|
||
bool NixRepl::getLine(string & line)
|
||
{
|
||
struct sigaction act, old;
|
||
act.sa_handler = sigintHandler;
|
||
sigfillset(&act.sa_mask);
|
||
act.sa_flags = 0;
|
||
if (sigaction(SIGINT, &act, &old))
|
||
throw SysError("installing handler for SIGINT");
|
||
|
||
if (sigsetjmp(sigintJmpBuf, 1))
|
||
line = "";
|
||
else {
|
||
curRepl = this;
|
||
rl_completion_entry_function = completerThunk;
|
||
|
||
char * s = readline("nix-repl> ");
|
||
if (!s) return false;
|
||
line = chomp(string(s));
|
||
free(s);
|
||
if (line != "") {
|
||
add_history(line.c_str());
|
||
append_history(1, 0);
|
||
}
|
||
}
|
||
|
||
_isInterrupted = 0;
|
||
|
||
if (sigaction(SIGINT, &old, 0))
|
||
throw SysError("restoring handler for SIGINT");
|
||
|
||
return true;
|
||
}
|
||
|
||
|
||
void NixRepl::completePrefix(string prefix)
|
||
{
|
||
completions.clear();
|
||
|
||
size_t dot = prefix.rfind('.');
|
||
|
||
if (dot == string::npos) {
|
||
/* This is a variable name; look it up in the current scope. */
|
||
StringSet::iterator i = varNames.lower_bound(prefix);
|
||
while (i != varNames.end()) {
|
||
if (string(*i, 0, prefix.size()) != prefix) break;
|
||
completions.insert(*i);
|
||
i++;
|
||
}
|
||
} else {
|
||
try {
|
||
/* This is an expression that should evaluate to an
|
||
attribute set. Evaluate it to get the names of the
|
||
attributes. */
|
||
string expr(prefix, 0, dot);
|
||
string prefix2 = string(prefix, dot + 1);
|
||
|
||
Expr * e = parseString(expr);
|
||
Value v;
|
||
e->eval(state, *env, v);
|
||
state.forceAttrs(v);
|
||
|
||
foreach (Bindings::iterator, i, *v.attrs) {
|
||
string name = i->name;
|
||
if (string(name, 0, prefix2.size()) != prefix2) continue;
|
||
completions.insert(expr + "." + name);
|
||
}
|
||
|
||
} catch (ParseError & e) {
|
||
// Quietly ignore parse errors.
|
||
} catch (EvalError & e) {
|
||
// Quietly ignore evaluation errors.
|
||
} catch (UndefinedVarError & e) {
|
||
// Quietly ignore undefined variable errors.
|
||
}
|
||
}
|
||
}
|
||
|
||
|
||
static int runProgram(const string & program, const Strings & args)
|
||
{
|
||
std::vector<const char *> cargs; /* careful with c_str()! */
|
||
cargs.push_back(program.c_str());
|
||
for (Strings::const_iterator i = args.begin(); i != args.end(); ++i)
|
||
cargs.push_back(i->c_str());
|
||
cargs.push_back(0);
|
||
|
||
Pid pid;
|
||
pid = fork();
|
||
if (pid == -1) throw SysError("forking");
|
||
if (pid == 0) {
|
||
restoreAffinity();
|
||
execvp(program.c_str(), (char * *) &cargs[0]);
|
||
_exit(1);
|
||
}
|
||
|
||
return pid.wait(true);
|
||
}
|
||
|
||
|
||
bool isVarName(const string & s)
|
||
{
|
||
// FIXME: not quite correct.
|
||
foreach (string::const_iterator, i, s)
|
||
if (!((*i >= 'a' && *i <= 'z') ||
|
||
(*i >= 'A' && *i <= 'Z') ||
|
||
(*i >= '0' && *i <= '9') ||
|
||
*i == '_' || *i == '\''))
|
||
return false;
|
||
return true;
|
||
}
|
||
|
||
|
||
bool NixRepl::processLine(string line)
|
||
{
|
||
if (line == "") return true;
|
||
|
||
string command, arg;
|
||
|
||
if (line[0] == ':') {
|
||
size_t p = line.find(' ');
|
||
command = string(line, 0, p);
|
||
if (p != string::npos) arg = removeWhitespace(string(line, p));
|
||
} else {
|
||
arg = line;
|
||
}
|
||
|
||
if (command == ":?" || command == ":help") {
|
||
cout << "The following commands are available:\n"
|
||
<< "\n"
|
||
<< " <expr> Evaluate and print expression\n"
|
||
<< " <x> = <expr> Bind expression to variable\n"
|
||
<< " :a <expr> Add attributes from resulting set to scope\n"
|
||
<< " :b <expr> Build derivation\n"
|
||
<< " :l <path> Load Nix expression and add it to scope\n"
|
||
<< " :p <expr> Evaluate and print expression recursively\n"
|
||
<< " :q Exit nix-repl\n"
|
||
<< " :r Reload all files\n"
|
||
<< " :s <expr> Build dependencies of derivation, then start nix-shell\n"
|
||
<< " :t <expr> Describe result of evaluation\n";
|
||
}
|
||
|
||
else if (command == ":a" || command == ":add") {
|
||
Value v;
|
||
evalString(arg, v);
|
||
addAttrsToScope(v);
|
||
}
|
||
|
||
else if (command == ":l" || command == ":load") {
|
||
state.resetFileCache();
|
||
loadFile(arg);
|
||
}
|
||
|
||
else if (command == ":r" || command == ":reload") {
|
||
state.resetFileCache();
|
||
reloadFiles();
|
||
}
|
||
|
||
else if (command == ":t") {
|
||
Value v;
|
||
evalString(arg, v);
|
||
std::cout << showType(v) << std::endl;
|
||
}
|
||
|
||
else if (command == ":b" || command == ":s") {
|
||
Value v;
|
||
evalString(arg, v);
|
||
DrvInfo drvInfo(state);
|
||
if (!getDerivation(state, v, drvInfo, false))
|
||
throw Error("expression does not evaluation to a derivation, so I can't build it");
|
||
Path drvPath = drvInfo.queryDrvPath();
|
||
if (drvPath == "" || !store->isValidPath(drvPath))
|
||
throw Error("expression did not evaluate to a valid derivation");
|
||
|
||
if (command == ":b") {
|
||
/* We could do the build in this process using buildPaths(),
|
||
but doing it in a child makes it easier to recover from
|
||
problems / SIGINT. */
|
||
if (runProgram("nix-store", Strings{"-r", drvPath}) == 0) {
|
||
Derivation drv = readDerivation(drvPath);
|
||
std::cout << std::endl << "this derivation produced the following outputs:" << std::endl;
|
||
foreach (DerivationOutputs::iterator, i, drv.outputs)
|
||
std::cout << format(" %1% -> %2%") % i->first % i->second.path << std::endl;
|
||
}
|
||
} else
|
||
runProgram("nix-shell", Strings{drvPath});
|
||
}
|
||
|
||
else if (command == ":p" || command == ":print") {
|
||
Value v;
|
||
evalString(arg, v);
|
||
printValue(std::cout, v, 1000000000) << std::endl;
|
||
}
|
||
|
||
else if (command == ":q" || command == ":quit")
|
||
return false;
|
||
|
||
else if (command != "")
|
||
throw Error(format("unknown command ‘%1%’") % command);
|
||
|
||
else {
|
||
size_t p = line.find('=');
|
||
string name;
|
||
if (p != string::npos &&
|
||
isVarName(name = removeWhitespace(string(line, 0, p))))
|
||
{
|
||
Expr * e = parseString(string(line, p + 1));
|
||
Value & v(*state.allocValue());
|
||
v.type = tThunk;
|
||
v.thunk.env = env;
|
||
v.thunk.expr = e;
|
||
addVarToScope(state.symbols.create(name), v);
|
||
} else {
|
||
Value v;
|
||
evalString(line, v);
|
||
printValue(std::cout, v, 1) << std::endl;
|
||
}
|
||
}
|
||
|
||
return true;
|
||
}
|
||
|
||
|
||
void NixRepl::loadFile(const Path & path)
|
||
{
|
||
loadedFiles.remove(path);
|
||
loadedFiles.push_back(path);
|
||
Value v, v2;
|
||
state.evalFile(lookupFileArg(state, path), v);
|
||
Bindings bindings;
|
||
state.autoCallFunction(bindings, v, v2);
|
||
addAttrsToScope(v2);
|
||
}
|
||
|
||
|
||
void NixRepl::initEnv()
|
||
{
|
||
env = &state.allocEnv(envSize);
|
||
env->up = &state.baseEnv;
|
||
displ = 0;
|
||
staticEnv.vars.clear();
|
||
|
||
varNames.clear();
|
||
foreach (StaticEnv::Vars::iterator, i, state.staticBaseEnv.vars)
|
||
varNames.insert(i->first);
|
||
}
|
||
|
||
|
||
void NixRepl::reloadFiles()
|
||
{
|
||
initEnv();
|
||
|
||
Strings old = loadedFiles;
|
||
loadedFiles.clear();
|
||
|
||
foreach (Strings::iterator, i, old) {
|
||
if (i != old.begin()) std::cout << std::endl;
|
||
std::cout << format("Loading ‘%1%’...") % *i << std::endl;
|
||
loadFile(*i);
|
||
}
|
||
}
|
||
|
||
|
||
void NixRepl::addAttrsToScope(Value & attrs)
|
||
{
|
||
state.forceAttrs(attrs);
|
||
foreach (Bindings::iterator, i, *attrs.attrs)
|
||
addVarToScope(i->name, *i->value);
|
||
std::cout << format("Added %1% variables.") % attrs.attrs->size() << std::endl;
|
||
}
|
||
|
||
|
||
void NixRepl::addVarToScope(const Symbol & name, Value & v)
|
||
{
|
||
if (displ >= envSize)
|
||
throw Error("environment full; cannot add more variables");
|
||
staticEnv.vars[name] = displ;
|
||
env->values[displ++] = &v;
|
||
varNames.insert((string) name);
|
||
}
|
||
|
||
|
||
Expr * NixRepl::parseString(string s)
|
||
{
|
||
Expr * e = state.parseExprFromString(s, curDir, staticEnv);
|
||
return e;
|
||
}
|
||
|
||
|
||
void NixRepl::evalString(string s, Value & v)
|
||
{
|
||
Expr * e = parseString(s);
|
||
e->eval(state, *env, v);
|
||
state.forceValue(v);
|
||
}
|
||
|
||
|
||
std::ostream & NixRepl::printValue(std::ostream & str, Value & v, unsigned int maxDepth)
|
||
{
|
||
ValuesSeen seen;
|
||
return printValue(str, v, maxDepth, seen);
|
||
}
|
||
|
||
|
||
// FIXME: lot of cut&paste from Nix's eval.cc.
|
||
std::ostream & NixRepl::printValue(std::ostream & str, Value & v, unsigned int maxDepth, ValuesSeen & seen)
|
||
{
|
||
str.flush();
|
||
checkInterrupt();
|
||
|
||
state.forceValue(v);
|
||
|
||
switch (v.type) {
|
||
|
||
case tInt:
|
||
str << v.integer;
|
||
break;
|
||
|
||
case tBool:
|
||
str << (v.boolean ? "true" : "false");
|
||
break;
|
||
|
||
case tString:
|
||
str << "\"";
|
||
for (const char * i = v.string.s; *i; i++)
|
||
if (*i == '\"' || *i == '\\') str << "\\" << *i;
|
||
else if (*i == '\n') str << "\\n";
|
||
else if (*i == '\r') str << "\\r";
|
||
else if (*i == '\t') str << "\\t";
|
||
else str << *i;
|
||
str << "\"";
|
||
break;
|
||
|
||
case tPath:
|
||
str << v.path; // !!! escaping?
|
||
break;
|
||
|
||
case tNull:
|
||
str << "null";
|
||
break;
|
||
|
||
case tAttrs: {
|
||
seen.insert(&v);
|
||
|
||
bool isDrv = state.isDerivation(v);
|
||
|
||
if (isDrv) {
|
||
str << "«derivation ";
|
||
Bindings::iterator i = v.attrs->find(state.sDrvPath);
|
||
PathSet context;
|
||
Path drvPath = i != v.attrs->end() ? state.coerceToPath(*i->pos, *i->value, context) : "???";
|
||
str << drvPath << "»";
|
||
}
|
||
|
||
else if (maxDepth > 0) {
|
||
str << "{ ";
|
||
|
||
typedef std::map<string, Value *> Sorted;
|
||
Sorted sorted;
|
||
foreach (Bindings::iterator, i, *v.attrs)
|
||
sorted[i->name] = i->value;
|
||
|
||
/* If this is a derivation, then don't show the
|
||
self-references ("all", "out", etc.). */
|
||
StringSet hidden;
|
||
if (isDrv) {
|
||
hidden.insert("all");
|
||
Bindings::iterator i = v.attrs->find(state.sOutputs);
|
||
if (i == v.attrs->end())
|
||
hidden.insert("out");
|
||
else {
|
||
state.forceList(*i->value);
|
||
for (unsigned int j = 0; j < i->value->list.length; ++j)
|
||
hidden.insert(state.forceStringNoCtx(*i->value->list.elems[j]));
|
||
}
|
||
}
|
||
|
||
foreach (Sorted::iterator, i, sorted) {
|
||
str << i->first << " = ";
|
||
if (hidden.find(i->first) != hidden.end())
|
||
str << "«...»";
|
||
else if (seen.find(i->second) != seen.end())
|
||
str << "«repeated»";
|
||
else
|
||
try {
|
||
printValue(str, *i->second, maxDepth - 1, seen);
|
||
} catch (AssertionError & e) {
|
||
str << "«error: " << e.msg() << "»";
|
||
}
|
||
str << "; ";
|
||
}
|
||
|
||
str << "}";
|
||
} else
|
||
str << "{ ... }";
|
||
|
||
break;
|
||
}
|
||
|
||
case tList:
|
||
seen.insert(&v);
|
||
|
||
str << "[ ";
|
||
if (maxDepth > 0)
|
||
for (unsigned int n = 0; n < v.list.length; ++n) {
|
||
if (seen.find(v.list.elems[n]) != seen.end())
|
||
str << "«repeated»";
|
||
else
|
||
try {
|
||
printValue(str, *v.list.elems[n], maxDepth - 1, seen);
|
||
} catch (AssertionError & e) {
|
||
str << "«error: " << e.msg() << "»";
|
||
}
|
||
str << " ";
|
||
}
|
||
else
|
||
str << "... ";
|
||
str << "]";
|
||
break;
|
||
|
||
case tLambda:
|
||
str << "«lambda»";
|
||
break;
|
||
|
||
case tPrimOp:
|
||
str << "«primop»";
|
||
break;
|
||
|
||
case tPrimOpApp:
|
||
str << "«primop-app»";
|
||
break;
|
||
|
||
default:
|
||
str << "«unknown»";
|
||
break;
|
||
}
|
||
|
||
return str;
|
||
}
|
||
|
||
|
||
void run(Strings args)
|
||
{
|
||
NixRepl repl;
|
||
repl.mainLoop(args);
|
||
}
|