lix/src/nix-build/nix-build.cc
John Ericson 296831f641 Move enabled experimental feature to libutil struct
This is needed in subsequent commits to allow the settings and CLI args
infrastructure itself to read this setting.
2023-03-20 11:05:22 -04:00

643 lines
22 KiB
C++

#include <cstring>
#include <fstream>
#include <iostream>
#include <filesystem>
#include <regex>
#include <sstream>
#include <vector>
#include <map>
#include <nlohmann/json.hpp>
#include "parsed-derivations.hh"
#include "store-api.hh"
#include "local-fs-store.hh"
#include "globals.hh"
#include "derivations.hh"
#include "util.hh"
#include "shared.hh"
#include "path-with-outputs.hh"
#include "eval.hh"
#include "eval-inline.hh"
#include "get-drvs.hh"
#include "common-eval-args.hh"
#include "attr-path.hh"
#include "legacy.hh"
using namespace nix;
using namespace std::string_literals;
extern char * * environ __attribute__((weak));
/* Recreate the effect of the perl shellwords function, breaking up a
* string into arguments like a shell word, including escapes
*/
static std::vector<std::string> shellwords(const std::string & s)
{
std::regex whitespace("^(\\s+).*");
auto begin = s.cbegin();
std::vector<std::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;
}
static void main_nix_build(int argc, char * * argv)
{
auto dryRun = false;
auto runEnv = std::regex_search(argv[0], std::regex("nix-shell$"));
auto pure = false;
auto fromArgs = false;
auto packages = false;
// Same condition as bash uses for interactive shells
auto interactive = isatty(STDIN_FILENO) && isatty(STDERR_FILENO);
Strings attrPaths;
Strings left;
RepairFlag repair = NoRepair;
BuildMode buildMode = bmNormal;
bool readStdin = false;
std::string envCommand; // interactive shell
Strings envExclude;
auto myName = runEnv ? "nix-shell" : "nix-build";
auto inShebang = false;
std::string script;
std::vector<std::string> savedArgs;
AutoDelete tmpDir(createTempDir("", myName));
std::string outLink = "./result";
// List of environment variables kept for --pure
std::set<std::string> keepVars{
"HOME", "XDG_RUNTIME_DIR", "USER", "LOGNAME", "DISPLAY",
"WAYLAND_DISPLAY", "WAYLAND_SOCKET", "PATH", "TERM", "IN_NIX_SHELL",
"NIX_SHELL_PRESERVE_PROMPT", "TZ", "PAGER", "NIX_BUILD_SHELL", "SHLVL",
"http_proxy", "https_proxy", "ftp_proxy", "all_proxy", "no_proxy"
};
Strings args;
for (int i = 1; i < argc; ++i)
args.push_back(argv[i]);
// Heuristic to see if we're invoked as a shebang script, namely,
// if we have at least one argument, it's the name of an
// executable file, and it starts with "#!".
if (runEnv && argc > 1) {
script = argv[1];
try {
auto lines = tokenizeString<Strings>(readFile(script), "\n");
if (std::regex_search(lines.front(), std::regex("^#!"))) {
lines.pop_front();
inShebang = true;
for (int i = 2; i < argc; ++i)
savedArgs.push_back(argv[i]);
args.clear();
for (auto line : lines) {
line = chomp(line);
std::smatch match;
if (std::regex_match(line, match, std::regex("^#!\\s*nix-shell (.*)$")))
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" || *arg == "--indirect")
; // 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 == "--dry-run")
dryRun = true;
else if (*arg == "--repair") {
repair = Repair;
buildMode = bmRepair;
}
else if (*arg == "--run-env") // obsolete
runEnv = true;
else if (runEnv && (*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 (runEnv && (*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 = fmt("exec %1% %2% -e 'load(ARGV.shift)' -- %3% %4%", execArgs, interpreter, shellEscape(script), joined.str());
} else {
envCommand = fmt("exec %1% %2% %3% %4%", execArgs, interpreter, shellEscape(script), joined.str());
}
}
else if (*arg == "--keep")
keepVars.insert(getArg(*arg, arg, end));
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();
auto evalStore = myArgs.evalStoreUrl ? openStore(*myArgs.evalStoreUrl) : store;
auto state = std::make_unique<EvalState>(myArgs.searchPath, evalStore, store);
state->repair = repair;
auto autoArgs = myArgs.getAutoArgs(*state);
auto autoArgsWithInNixShell = autoArgs;
if (runEnv) {
auto newArgs = state->buildBindings(autoArgsWithInNixShell->size() + 1);
newArgs.alloc("inNixShell").mkBool(true);
for (auto & i : *autoArgs) newArgs.insert(i);
autoArgsWithInNixShell = newArgs.finish();
}
if (packages) {
std::ostringstream joined;
joined << "{...}@args: with import <nixpkgs> args; (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);
DrvInfos drvs;
/* Parse the expressions. */
std::vector<Expr *> exprs;
if (readStdin)
exprs = {state->parseStdin()};
else
for (auto i : left) {
if (fromArgs)
exprs.push_back(state->parseExprFromString(std::move(i), absPath(".")));
else {
auto absolute = i;
try {
absolute = canonPath(absPath(i), true);
} catch (Error & e) {};
auto [path, outputNames] = parsePathWithOutputs(absolute);
if (evalStore->isStorePath(path) && hasSuffix(path, ".drv"))
drvs.push_back(DrvInfo(*state, evalStore, absolute));
else
/* If we're in a #! script, interpret filenames
relative to the script. */
exprs.push_back(state->parseExprFromFile(resolveExprPath(state->checkSourcePath(lookupFileArg(*state,
inShebang && !packages ? absPath(i, absPath(dirOf(script))) : i)))));
}
}
/* Evaluate them into derivations. */
if (attrPaths.empty()) attrPaths = {""};
for (auto e : exprs) {
Value vRoot;
state->eval(e, vRoot);
std::function<bool(const Value & v)> takesNixShellAttr;
takesNixShellAttr = [&](const Value & v) {
if (!runEnv) {
return false;
}
bool add = false;
if (v.type() == nFunction && v.lambda.fun->hasFormals()) {
for (auto & i : v.lambda.fun->formals->formals) {
if (state->symbols[i.name] == "inNixShell") {
add = true;
break;
}
}
}
return add;
};
for (auto & i : attrPaths) {
Value & v(*findAlongAttrPath(
*state,
i,
takesNixShellAttr(vRoot) ? *autoArgsWithInNixShell : *autoArgs,
vRoot
).first);
state->forceValue(v, [&]() { return v.determinePos(noPos); });
getDerivations(
*state,
v,
"",
takesNixShellAttr(v) ? *autoArgsWithInNixShell : *autoArgs,
drvs,
false
);
}
}
state->printStats();
auto buildPaths = [&](const std::vector<DerivedPath> & paths) {
/* Note: we do this even when !printMissing to efficiently
fetch binary cache data. */
uint64_t downloadSize, narSize;
StorePathSet 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, evalStore);
};
if (runEnv) {
if (drvs.size() != 1)
throw UsageError("nix-shell requires a single derivation");
auto & drvInfo = drvs.front();
auto drv = evalStore->derivationFromPath(drvInfo.requireDrvPath());
std::vector<DerivedPath> pathsToBuild;
RealisedPath::Set pathsToCopy;
/* 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");
std::optional<StorePath> shellDrv;
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");
auto bashDrv = drv->requireDrvPath();
pathsToBuild.push_back(DerivedPath::Built {
.drvPath = bashDrv,
.outputs = OutputsSpec::Names {"out"},
});
pathsToCopy.insert(bashDrv);
shellDrv = bashDrv;
} catch (Error & e) {
logError(e.info());
notice("will use bash from your environment");
shell = "bash";
}
}
// Build or fetch all dependencies of the derivation.
for (const auto & [inputDrv0, inputOutputs] : drv.inputDrvs) {
// To get around lambda capturing restrictions in the
// standard.
const auto & inputDrv = inputDrv0;
if (std::all_of(envExclude.cbegin(), envExclude.cend(),
[&](const std::string & exclude) {
return !std::regex_search(store->printStorePath(inputDrv), std::regex(exclude));
}))
{
pathsToBuild.push_back(DerivedPath::Built {
.drvPath = inputDrv,
.outputs = OutputsSpec::Names { inputOutputs },
});
pathsToCopy.insert(inputDrv);
}
}
for (const auto & src : drv.inputSrcs) {
pathsToBuild.push_back(DerivedPath::Opaque{src});
pathsToCopy.insert(src);
}
buildPaths(pathsToBuild);
if (dryRun) return;
if (shellDrv) {
auto shellDrvOutputs = store->queryPartialDerivationOutputMap(shellDrv.value());
shell = store->printStorePath(shellDrvOutputs.at("out").value()) + "/bin/bash";
}
if (experimentalFeatureSettings.isEnabled(Xp::CaDerivations)) {
auto resolvedDrv = drv.tryResolve(*store);
assert(resolvedDrv && "Successfully resolved the derivation");
drv = *resolvedDrv;
}
// Set the environment.
auto env = getEnv();
auto tmp = getEnv("TMPDIR");
if (!tmp) tmp = getEnv("XDG_RUNTIME_DIR").value_or("/tmp");
if (pure) {
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>(getOr(drv.env, "passAsFile", ""));
bool keepTmp = false;
int fileNr = 0;
for (auto & var : drv.env)
if (passAsFile.count(var.first)) {
keepTmp = true;
auto 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;
std::string structuredAttrsRC;
if (env.count("__json")) {
StorePathSet inputs;
for (auto & [depDrvPath, wantedDepOutputs] : drv.inputDrvs) {
auto outputs = evalStore->queryPartialDerivationOutputMap(depDrvPath);
for (auto & i : wantedDepOutputs) {
auto o = outputs.at(i);
store->computeFSClosure(*o, inputs);
}
}
ParsedDerivation parsedDrv(drvInfo.requireDrvPath(), drv);
if (auto structAttrs = parsedDrv.prepareStructuredAttrs(*store, inputs)) {
auto json = structAttrs.value();
structuredAttrsRC = writeStructuredAttrsShell(json);
auto attrsJSON = (Path) tmpDir + "/.attrs.json";
writeFile(attrsJSON, json.dump());
auto attrsSH = (Path) tmpDir + "/.attrs.sh";
writeFile(attrsSH, structuredAttrsRC);
env["NIX_ATTRS_SH_FILE"] = attrsSH;
env["NIX_ATTRS_JSON_FILE"] = attrsJSON;
keepTmp = true;
}
}
/* 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 $PATH directories. */
auto rcfile = (Path) tmpDir + "/rc";
std::string rc = fmt(
R"(_nix_shell_clean_tmpdir() { command rm -rf %1%; }; )"s +
(keepTmp ?
"trap _nix_shell_clean_tmpdir EXIT; "
"exitHooks+=(_nix_shell_clean_tmpdir); "
"failureHooks+=(_nix_shell_clean_tmpdir); ":
"_nix_shell_clean_tmpdir; ") +
(pure ? "" : "[ -n \"$PS1\" ] && [ -e ~/.bashrc ] && source ~/.bashrc;") +
"%2%"
// always clear PATH.
// when nix-shell is run impure, we rehydrate it with the `p=$PATH` above
"unset PATH;"
"dontAddDisableDepTrack=1;\n"
+ structuredAttrsRC +
"\n[ -e $stdenv/setup ] && source $stdenv/setup; "
"%3%"
"PATH=%4%:\"$PATH\"; "
"SHELL=%5%; "
"BASH=%5%; "
"set +e; "
R"s([ -n "$PS1" -a -z "$NIX_SHELL_PRESERVE_PROMPT" ] && )s" +
(getuid() == 0 ? R"s(PS1='\n\[\033[1;31m\][nix-shell:\w]\$\[\033[0m\] '; )s"
: R"s(PS1='\n\[\033[1;32m\][nix-shell:\w]\$\[\033[0m\] '; )s") +
"if [ \"$(type -t runHook)\" = function ]; then runHook shellHook; fi; "
"unset NIX_ENFORCE_PURITY; "
"shopt -u nullglob; "
"unset TZ; %6%"
"shopt -s execfail;"
"%7%",
shellEscape(tmpDir),
(pure ? "" : "p=$PATH; "),
(pure ? "" : "PATH=$PATH:$p; unset p; "),
shellEscape(dirOf(*shell)),
shellEscape(*shell),
(getenv("TZ") ? (std::string("export TZ=") + shellEscape(getenv("TZ")) + "; ") : ""),
envCommand);
vomit("Sourcing nix-shell with file %s and contents:\n%s", rcfile, rc);
writeFile(rcfile, rc);
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);
restoreProcessContext();
logger->stop();
execvp(shell->c_str(), argPtrs.data());
throw SysError("executing shell '%s'", *shell);
}
else {
std::vector<DerivedPath> pathsToBuild;
std::vector<std::pair<StorePath, std::string>> pathsToBuildOrdered;
RealisedPath::Set drvsToCopy;
std::map<StorePath, std::pair<size_t, StringSet>> drvMap;
for (auto & drvInfo : drvs) {
auto drvPath = drvInfo.requireDrvPath();
auto outputName = drvInfo.queryOutputName();
if (outputName == "")
throw Error("derivation '%s' lacks an 'outputName' attribute", store->printStorePath(drvPath));
pathsToBuild.push_back(DerivedPath::Built{drvPath, OutputsSpec::Names{outputName}});
pathsToBuildOrdered.push_back({drvPath, {outputName}});
drvsToCopy.insert(drvPath);
auto i = drvMap.find(drvPath);
if (i != drvMap.end())
i->second.second.insert(outputName);
else
drvMap[drvPath] = {drvMap.size(), {outputName}};
}
buildPaths(pathsToBuild);
if (dryRun) return;
std::vector<StorePath> outPaths;
for (auto & [drvPath, outputName] : pathsToBuildOrdered) {
auto & [counter, _wantedOutputs] = drvMap.at({drvPath});
std::string drvPrefix = outLink;
if (counter)
drvPrefix += fmt("-%d", counter + 1);
auto builtOutputs = evalStore->queryPartialDerivationOutputMap(drvPath);
auto maybeOutputPath = builtOutputs.at(outputName);
assert(maybeOutputPath);
auto outputPath = *maybeOutputPath;
if (auto store2 = store.dynamic_pointer_cast<LocalFSStore>()) {
std::string symlink = drvPrefix;
if (outputName != "out") symlink += "-" + outputName;
store2->addPermRoot(outputPath, absPath(symlink));
}
outPaths.push_back(outputPath);
}
logger->stop();
for (auto & path : outPaths)
std::cout << store->printStorePath(path) << '\n';
}
}
static RegisterLegacyCommand r_nix_build("nix-build", main_nix_build);
static RegisterLegacyCommand r_nix_shell("nix-shell", main_nix_build);