#include <cstring>
#include <fstream>
#include <iostream>
#include <regex>
#include <sstream>
#include <vector>
#include "store-api.hh"
#include "globals.hh"
#include "derivations.hh"
#include "affinity.hh"
#include "util.hh"
#include "shared.hh"
#include "eval.hh"
#include "eval-inline.hh"
#include "get-drvs.hh"
#include "common-eval-args.hh"
#include "attr-path.hh"
using namespace nix;
using namespace std::string_literals;
extern char * * environ;
/* Recreate the effect of the perl shellwords function, breaking up a
* string into arguments like a shell word, including escapes
*/
std::vector<string> shellwords(const string & s)
{
std::regex whitespace("^(\\s+).*");
auto begin = s.cbegin();
std::vector<string> res;
std::string cur;
enum state {
sBegin,
sQuote
};
state st = sBegin;
auto it = begin;
for (; it != s.cend(); ++it) {
if (st == sBegin) {
std::smatch match;
if (regex_search(it, s.cend(), match, whitespace)) {
cur.append(begin, it);
res.push_back(cur);
cur.clear();
it = match[1].second;
begin = it;
}
}
switch (*it) {
case '"':
cur.append(begin, it);
begin = it + 1;
st = st == sBegin ? sQuote : sBegin;
break;
case '\\':
/* perl shellwords mostly just treats the next char as part of the string with no special processing */
cur.append(begin, it);
begin = ++it;
break;
}
}
cur.append(begin, it);
if (!cur.empty()) res.push_back(cur);
return res;
}
void mainWrapped(int argc, char * * argv)
{
initNix();
initGC();
auto dryRun = false;
auto runEnv = std::regex_search(argv[0], std::regex("nix-shell$"));
auto pure = false;
auto fromArgs = false;
auto packages = false;
// Same condition as bash uses for interactive shells
auto interactive = isatty(STDIN_FILENO) && isatty(STDERR_FILENO);
Strings attrPaths;
Strings left;
RepairFlag repair = NoRepair;
Path gcRoot;
BuildMode buildMode = bmNormal;
bool readStdin = false;
auto shell = getEnv("SHELL", "/bin/sh");
std::string envCommand; // interactive shell
Strings envExclude;
auto myName = runEnv ? "nix-shell" : "nix-build";
auto inShebang = false;
std::string script;
std::vector<string> savedArgs;
AutoDelete tmpDir(createTempDir("", myName));
std::string outLink = "./result";
Strings args;
for (int i = 1; i < argc; ++i)
args.push_back(argv[i]);
// Heuristic to see if we're invoked as a shebang script, namely,
// if we have at least one argument, it's the name of an
// executable file, and it starts with "#!".
if (runEnv && argc > 1 && !std::regex_search(argv[1], std::regex("nix-shell"))) {
script = argv[1];
try {
auto lines = tokenizeString<Strings>(readFile(script), "\n");
if (std::regex_search(lines.front(), std::regex("^#!"))) {
lines.pop_front();
inShebang = true;
for (int i = 2; i < argc; ++i)
savedArgs.push_back(argv[i]);
args.clear();
for (auto line : lines) {
line = chomp(line);
std::smatch match;
if (std::regex_match(line, match, std::regex("^#!\\s*nix-shell (.*)$")))
for (const auto & word : shellwords(match[1].str()))
args.push_back(word);
}
}
} catch (SysError &) { }
}
struct MyArgs : LegacyArgs, MixEvalArgs
{
using LegacyArgs::LegacyArgs;
};
MyArgs myArgs(myName, [&](Strings::iterator & arg, const Strings::iterator & end) {
if (*arg == "--help") {
deletePath(tmpDir);
showManPage(myName);
}
else if (*arg == "--version")
printVersion(myName);
else if (*arg == "--add-drv-link")
; // obsolete
else if (*arg == "--no-out-link" || *arg == "--no-link")
outLink = (Path) tmpDir + "/result";
else if (*arg == "--attr" || *arg == "-A")
attrPaths.push_back(getArg(*arg, arg, end));
else if (*arg == "--drv-link")
getArg(*arg, arg, end); // obsolete
else if (*arg == "--out-link" || *arg == "-o")
outLink = getArg(*arg, arg, end);
else if (*arg == "--add-root")
gcRoot = getArg(*arg, arg, end);
else if (*arg == "--dry-run")
dryRun = true;
else if (*arg == "--repair") {
repair = Repair;
buildMode = bmRepair;
}
else if (*arg == "--run-env") // obsolete
runEnv = true;
else if (*arg == "--command" || *arg == "--run") {
if (*arg == "--run")
interactive = false;
envCommand = getArg(*arg, arg, end) + "\nexit";
}
else if (*arg == "--check")
buildMode = bmCheck;
else if (*arg == "--exclude")
envExclude.push_back(getArg(*arg, arg, end));
else if (*arg == "--expr" || *arg == "-E")
fromArgs = true;
else if (*arg == "--pure") pure = true;
else if (*arg == "--impure") pure = false;
else if (*arg == "--packages" || *arg == "-p")
packages = true;
else if (inShebang && *arg == "-i") {
auto interpreter = getArg(*arg, arg, end);
interactive = false;
auto execArgs = "";
// Überhack to support Perl. Perl examines the shebang and
// executes it unless it contains the string "perl" or "indir",
// or (undocumented) argv[0] does not contain "perl". Exploit
// the latter by doing "exec -a".
if (std::regex_search(interpreter, std::regex("perl")))
execArgs = "-a PERL";
std::ostringstream joined;
for (const auto & i : savedArgs)
joined << shellEscape(i) << ' ';
if (std::regex_search(interpreter, std::regex("ruby"))) {
// Hack for Ruby. Ruby also examines the shebang. It tries to
// read the shebang to understand which packages to read from. Since
// this is handled via nix-shell -p, we wrap our ruby script execution
// in ruby -e 'load' which ignores the shebangs.
envCommand = (format("exec %1% %2% -e 'load(\"%3%\") -- %4%") % execArgs % interpreter % script % joined.str()).str();
} else {
envCommand = (format("exec %1% %2% %3% %4%") % execArgs % interpreter % script % joined.str()).str();
}
}
else if (*arg == "-")
readStdin = true;
else if (*arg != "" && arg->at(0) == '-')
return false;
else
left.push_back(*arg);
return true;
});
myArgs.parseCmdline(args);
if (packages && fromArgs)
throw UsageError("'-p' and '-E' are mutually exclusive");
auto store = openStore();
EvalState state(myArgs.searchPath, store);
state.repair = repair;
Bindings & autoArgs = *myArgs.getAutoArgs(state);
if (packages) {
std::ostringstream joined;
joined << "with import <nixpkgs> { }; (pkgs.runCommandCC or pkgs.runCommand) \"shell\" { buildInputs = [ ";
for (const auto & i : left)
joined << '(' << i << ") ";
joined << "]; } \"\"";
fromArgs = true;
left = {joined.str()};
} else if (!fromArgs) {
if (left.empty() && runEnv && pathExists("shell.nix"))
left = {"shell.nix"};
if (left.empty())
left = {"default.nix"};
}
if (runEnv)
setenv("IN_NIX_SHELL", pure ? "pure" : "impure", 1);
/* Parse the expressions. */
std::vector<Expr *> exprs;
if (readStdin)
exprs = {state.parseStdin()};
else
for (auto i : left) {
if (fromArgs)
exprs.push_back(state.parseExprFromString(i, absPath(".")));
else
/* If we're in a #! script, interpret filenames
relative to the script. */
exprs.push_back(state.parseExprFromFile(resolveExprPath(lookupFileArg(state,
inShebang && !packages ? absPath(i, absPath(dirOf(script))) : i))));
}
/* Evaluate them into derivations. */
DrvInfos drvs;
if (attrPaths.empty()) attrPaths = {""};
for (auto e : exprs) {
Value vRoot;
state.eval(e, vRoot);
for (auto & i : attrPaths) {
Value & v(*findAlongAttrPath(state, i, autoArgs, vRoot));
state.forceValue(v);
getDerivations(state, v, "", autoArgs, drvs, false);
}
}
auto buildPaths = [&](const PathSet & paths) {
/* Note: we do this even when !printMissing to efficiently
fetch binary cache data. */
unsigned long long downloadSize, narSize;
PathSet willBuild, willSubstitute, unknown;
store->queryMissing(paths,
willBuild, willSubstitute, unknown, downloadSize, narSize);
if (settings.printMissing)
printMissing(ref<Store>(store), willBuild, willSubstitute, unknown, downloadSize, narSize);
if (!dryRun)
store->buildPaths(paths, buildMode);
};
if (runEnv) {
if (drvs.size() != 1)
throw UsageError("nix-shell requires a single derivation");
auto & drvInfo = drvs.front();
auto drv = store->derivationFromPath(drvInfo.queryDrvPath());
PathSet pathsToBuild;
/* Figure out what bash shell to use. If $NIX_BUILD_SHELL
is not set, then build bashInteractive from
<nixpkgs>. */
auto shell = getEnv("NIX_BUILD_SHELL", "");
if (shell == "") {
try {
auto expr = state.parseExprFromString("(import <nixpkgs> {}).bashInteractive", absPath("."));
Value v;
state.eval(expr, v);
auto drv = getDerivation(state, v, false);
if (!drv)
throw Error("the 'bashInteractive' attribute in <nixpkgs> did not evaluate to a derivation");
pathsToBuild.insert(drv->queryDrvPath());
shell = drv->queryOutPath() + "/bin/bash";
} catch (Error & e) {
printError("warning: %s; will use bash from your environment", e.what());
shell = "bash";
}
}
// Build or fetch all dependencies of the derivation.
for (const auto & input : drv.inputDrvs)
if (std::all_of(envExclude.cbegin(), envExclude.cend(), [&](const string & exclude) { return !std::regex_search(input.first, std::regex(exclude)); }))
pathsToBuild.insert(input.first);
for (const auto & src : drv.inputSrcs)
pathsToBuild.insert(src);
buildPaths(pathsToBuild);
if (dryRun) return;
// Set the environment.
auto env = getEnv();
auto tmp = getEnv("TMPDIR", getEnv("XDG_RUNTIME_DIR", "/tmp"));
if (pure) {
std::set<string> keepVars{"HOME", "USER", "LOGNAME", "DISPLAY", "PATH", "TERM", "IN_NIX_SHELL", "TZ", "PAGER", "NIX_BUILD_SHELL", "SHLVL"};
decltype(env) newEnv;
for (auto & i : env)
if (keepVars.count(i.first))
newEnv.emplace(i);
env = newEnv;
// NixOS hack: prevent /etc/bashrc from sourcing /etc/profile.
env["__ETC_PROFILE_SOURCED"] = "1";
}
env["NIX_BUILD_TOP"] = env["TMPDIR"] = env["TEMPDIR"] = env["TMP"] = env["TEMP"] = tmp;
env["NIX_STORE"] = store->storeDir;
env["NIX_BUILD_CORES"] = std::to_string(settings.buildCores);
auto passAsFile = tokenizeString<StringSet>(get(drv.env, "passAsFile", ""));
bool keepTmp = false;
int fileNr = 0;
for (auto & var : drv.env)
if (passAsFile.count(var.first)) {
keepTmp = true;
string fn = ".attr-" + std::to_string(fileNr++);
Path p = (Path) tmpDir + "/" + fn;
writeFile(p, var.second);
env[var.first + "Path"] = p;
} else
env[var.first] = var.second;
restoreAffinity();
/* Run a shell using the derivation's environment. For
convenience, source $stdenv/setup to setup additional
environment variables and shell functions. Also don't
lose the current $PATH directories. */
auto rcfile = (Path) tmpDir + "/rc";
writeFile(rcfile, fmt(
(keepTmp ? "" : "rm -rf '%1%'; "s) +
"[ -n \"$PS1\" ] && [ -e ~/.bashrc ] && source ~/.bashrc; "
"%2%"
"dontAddDisableDepTrack=1; "
"[ -e $stdenv/setup ] && source $stdenv/setup; "
"%3%"
"set +e; "
R"s([ -n "$PS1" ] && PS1='\n\[\033[1;32m\][nix-shell:\w]\$\[\033[0m\] '; )s"
"if [ \"$(type -t runHook)\" = function ]; then runHook shellHook; fi; "
"unset NIX_ENFORCE_PURITY; "
"unset NIX_INDENT_MAKE; "
"shopt -u nullglob; "
"unset TZ; %4%"
"%5%",
(Path) tmpDir,
(pure ? "" : "p=$PATH; "),
(pure ? "" : "PATH=$PATH:$p; unset p; "),
(getenv("TZ") ? (string("export TZ='") + getenv("TZ") + "'; ") : ""),
envCommand));
Strings envStrs;
for (auto & i : env)
envStrs.push_back(i.first + "=" + i.second);
auto args = interactive
? Strings{"bash", "--rcfile", rcfile}
: Strings{"bash", rcfile};
auto envPtrs = stringsToCharPtrs(envStrs);
environ = envPtrs.data();
auto argPtrs = stringsToCharPtrs(args);
restoreSignals();
execvp(shell.c_str(), argPtrs.data());
throw SysError("executing shell '%s'", shell);
}
else {
PathSet pathsToBuild;
std::map<Path, Path> drvPrefixes;
std::map<Path, Path> resultSymlinks;
std::vector<Path> outPaths;
for (auto & drvInfo : drvs) {
auto drvPath = drvInfo.queryDrvPath();
auto outPath = drvInfo.queryOutPath();
auto outputName = drvInfo.queryOutputName();
if (outputName == "")
throw Error("derivation '%s' lacks an 'outputName' attribute", drvPath);
pathsToBuild.insert(drvPath + "!" + outputName);
std::string drvPrefix;
auto i = drvPrefixes.find(drvPath);
if (i != drvPrefixes.end())
drvPrefix = i->second;
else {
drvPrefix = outLink;
if (drvPrefixes.size())
drvPrefix += fmt("-%d", drvPrefixes.size() + 1);
drvPrefixes[drvPath] = drvPrefix;
}
std::string symlink = drvPrefix;
if (outputName != "out") symlink += "-" + outputName;
resultSymlinks[symlink] = outPath;
outPaths.push_back(outPath);
}
buildPaths(pathsToBuild);
if (dryRun) return;
for (auto & symlink : resultSymlinks)
if (auto store2 = store.dynamic_pointer_cast<LocalFSStore>())
store2->addPermRoot(symlink.second, absPath(symlink.first), true);
for (auto & path : outPaths)
std::cout << path << '\n';
}
}
int main(int argc, char * * argv)
{
return handleExceptions(argv[0], [&]() {
return mainWrapped(argc, argv);
});
}
