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Diffstat (limited to 'third_party/nix/src/nix/repl.cc')
| -rw-r--r-- | third_party/nix/src/nix/repl.cc | 819 |
1 files changed, 0 insertions, 819 deletions
diff --git a/third_party/nix/src/nix/repl.cc b/third_party/nix/src/nix/repl.cc deleted file mode 100644 index b926d195ae..0000000000 --- a/third_party/nix/src/nix/repl.cc +++ /dev/null @@ -1,819 +0,0 @@ -#include <climits> -#include <csetjmp> -#include <cstdlib> -#include <cstring> -#include <iostream> -#include <utility> - -#include <absl/strings/ascii.h> -#include <absl/strings/match.h> -#include <editline.h> -#include <glog/logging.h> - -#include "libexpr/common-eval-args.hh" -#include "libexpr/eval-inline.hh" -#include "libexpr/eval.hh" -#include "libexpr/get-drvs.hh" -#include "libmain/shared.hh" -#include "libstore/derivations.hh" -#include "libstore/globals.hh" -#include "libstore/store-api.hh" -#include "libutil/affinity.hh" -#include "libutil/finally.hh" -#include "nix/command.hh" - -namespace nix { - -#define ESC_RED "\033[31m" -#define ESC_GRE "\033[32m" -#define ESC_YEL "\033[33m" -#define ESC_BLU "\033[34;1m" -#define ESC_MAG "\033[35m" -#define ESC_CYA "\033[36m" -#define ESC_END "\033[0m" - -struct NixRepl { - std::string curDir; - EvalState state; - std::unique_ptr<Bindings> autoArgs; - - Strings loadedFiles; - - const static int envSize = 32768; - StaticEnv staticEnv; - Env* env; - int displ; - StringSet varNames; - - const Path historyFile; - - NixRepl(const Strings& searchPath, const nix::ref<Store>& store); - ~NixRepl(); - void mainLoop(const std::vector<std::string>& files); - StringSet completePrefix(const std::string& prefix); - static bool getLine(std::string& input, const std::string& prompt); - Path getDerivationPath(Value& v); - bool processLine(std::string line); - void loadFile(const Path& path); - void initEnv(); - void reloadFiles(); - void addAttrsToScope(Value& attrs); - void addVarToScope(const Symbol& name, Value& v); - Expr* parseString(const std::string& s); - void evalString(std::string s, Value& v); - - using ValuesSeen = std::set<Value*>; - 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 [--help] [--version] [-I path] paths...\n" - << "\n" - << "nix-repl is a simple read-eval-print loop (REPL) for the Nix " - "package manager.\n" - << "\n" - << "Options:\n" - << " --help\n" - << " Prints out a summary of the command syntax and exits.\n" - << "\n" - << " --version\n" - << " Prints out the Nix version number on standard output " - "and exits.\n" - << "\n" - << " -I path\n" - << " Add a path to the Nix expression search path. This " - "option may be given\n" - << " multiple times. See the NIX_PATH environment variable " - "for information on\n" - << " the semantics of the Nix search path. Paths added " - "through -I take\n" - << " precedence over NIX_PATH.\n" - << "\n" - << " paths...\n" - << " A list of paths to files containing Nix expressions " - "which nix-repl will\n" - << " load and add to its scope.\n" - << "\n" - << " A path surrounded in < and > will be looked up in the " - "Nix expression search\n" - << " path, as in the Nix language itself.\n" - << "\n" - << " If an element of paths starts with http:// or " - "https://, it is interpreted\n" - << " as the URL of a tarball that will be downloaded and " - "unpacked to a temporary\n" - << " location. The tarball must include a single top-level " - "directory containing\n" - << " at least a file named default.nix.\n"; -} - -std::string removeWhitespace(std::string s) { - s = absl::StripTrailingAsciiWhitespace(s); - size_t n = s.find_first_not_of(" \n\r\t"); - if (n != std::string::npos) { - s = std::string(s, n); - } - return s; -} - -NixRepl::NixRepl(const Strings& searchPath, const nix::ref<Store>& store) - : state(searchPath, store), - staticEnv(false, &state.staticBaseEnv), - historyFile(getDataDir() + "/nix/repl-history") { - curDir = absPath("."); -} - -NixRepl::~NixRepl() { write_history(historyFile.c_str()); } - -static NixRepl* curRepl; // ugly - -static char* completionCallback(char* s, int* match) { - auto possible = curRepl->completePrefix(s); - if (possible.size() == 1) { - *match = 1; - auto* res = strdup(possible.begin()->c_str() + strlen(s)); - if (res == nullptr) { - throw Error("allocation failure"); - } - return res; - } - if (possible.size() > 1) { - auto checkAllHaveSameAt = [&](size_t pos) { - auto& first = *possible.begin(); - for (auto& p : possible) { - if (p.size() <= pos || p[pos] != first[pos]) { - return false; - } - } - return true; - }; - size_t start = strlen(s); - size_t len = 0; - while (checkAllHaveSameAt(start + len)) { - ++len; - } - if (len > 0) { - *match = 1; - auto* res = strdup(std::string(*possible.begin(), start, len).c_str()); - if (res == nullptr) { - throw Error("allocation failure"); - } - return res; - } - } - - *match = 0; - return nullptr; -} - -static int listPossibleCallback(char* s, char*** avp) { - auto possible = curRepl->completePrefix(s); - - if (possible.size() > (INT_MAX / sizeof(char*))) { - throw Error("too many completions"); - } - - int ac = 0; - char** vp = nullptr; - - auto check = [&](auto* p) { - if (!p) { - if (vp) { - while (--ac >= 0) { - free(vp[ac]); - } - free(vp); - } - throw Error("allocation failure"); - } - return p; - }; - - vp = check(static_cast<char**>(malloc(possible.size() * sizeof(char*)))); - - for (auto& p : possible) { - vp[ac++] = check(strdup(p.c_str())); - } - - *avp = vp; - - return ac; -} - -namespace { -// Used to communicate to NixRepl::getLine whether a signal occurred in -// ::readline. -volatile sig_atomic_t g_signal_received = 0; - -void sigintHandler(int signo) { g_signal_received = signo; } -} // namespace - -void NixRepl::mainLoop(const std::vector<std::string>& files) { - std::string error = ANSI_RED "error:" ANSI_NORMAL " "; - std::cout << "Welcome to Nix version " << nixVersion << ". Type :? for help." - << std::endl - << std::endl; - - for (auto& i : files) { - loadedFiles.push_back(i); - } - - reloadFiles(); - if (!loadedFiles.empty()) { - std::cout << std::endl; - } - - // Allow nix-repl specific settings in .inputrc - rl_readline_name = "nix-repl"; - createDirs(dirOf(historyFile)); - el_hist_size = 1000; - read_history(historyFile.c_str()); - curRepl = this; - rl_set_complete_func(completionCallback); - rl_set_list_possib_func(listPossibleCallback); - - std::string input; - - while (true) { - // When continuing input from previous lines, don't print a prompt, just - // align to the same number of chars as the prompt. - if (!getLine(input, input.empty() ? "nix-repl> " : " ")) { - break; - } - - try { - if (!removeWhitespace(input).empty() && !processLine(input)) { - return; - } - } catch (ParseError& e) { - if (e.msg().find("unexpected $end") != std::string::npos) { - // For parse errors on incomplete input, we continue waiting for the - // next line of input without clearing the input so far. - continue; - } - LOG(ERROR) << error << (settings.showTrace ? e.prefix() : "") << e.msg(); - - } catch (Error& e) { - LOG(ERROR) << error << (settings.showTrace ? e.prefix() : "") << e.msg(); - } catch (Interrupted& e) { - LOG(ERROR) << error << (settings.showTrace ? e.prefix() : "") << e.msg(); - } - - // We handled the current input fully, so we should clear it - // and read brand new input. - input.clear(); - std::cout << std::endl; - } -} - -bool NixRepl::getLine(std::string& input, const std::string& prompt) { - struct sigaction act; - struct sigaction old; - sigset_t savedSignalMask; - sigset_t set; - - auto setupSignals = [&]() { - act.sa_handler = sigintHandler; - sigfillset(&act.sa_mask); - act.sa_flags = 0; - if (sigaction(SIGINT, &act, &old) != 0) { - throw SysError("installing handler for SIGINT"); - } - - sigemptyset(&set); - sigaddset(&set, SIGINT); - if (sigprocmask(SIG_UNBLOCK, &set, &savedSignalMask) != 0) { - throw SysError("unblocking SIGINT"); - } - }; - auto restoreSignals = [&]() { - if (sigprocmask(SIG_SETMASK, &savedSignalMask, nullptr) != 0) { - throw SysError("restoring signals"); - } - - if (sigaction(SIGINT, &old, nullptr) != 0) { - throw SysError("restoring handler for SIGINT"); - } - }; - - setupSignals(); - char* s = readline(prompt.c_str()); - Finally doFree([&]() { free(s); }); - restoreSignals(); - - if (g_signal_received != 0) { - g_signal_received = 0; - input.clear(); - return true; - } - - if (s == nullptr) { - return false; - } - input += s; - input += '\n'; - return true; -} - -StringSet NixRepl::completePrefix(const std::string& prefix) { - StringSet completions; - - size_t start = prefix.find_last_of(" \n\r\t(){}[]"); - std::string prev; - std::string cur; - if (start == std::string::npos) { - prev = ""; - cur = prefix; - } else { - prev = std::string(prefix, 0, start + 1); - cur = std::string(prefix, start + 1); - } - - size_t slash; - size_t dot; - - if ((slash = cur.rfind('/')) != std::string::npos) { - try { - auto dir = std::string(cur, 0, slash); - auto prefix2 = std::string(cur, slash + 1); - for (auto& entry : readDirectory(dir.empty() ? "/" : dir)) { - if (entry.name[0] != '.' && absl::StartsWith(entry.name, prefix2)) { - completions.insert(prev + dir + "/" + entry.name); - } - } - } catch (Error&) { - } - } else if ((dot = cur.rfind('.')) == std::string::npos) { - /* This is a variable name; look it up in the current scope. */ - auto i = varNames.lower_bound(cur); - while (i != varNames.end()) { - if (std::string(*i, 0, cur.size()) != cur) { - break; - } - completions.insert(prev + *i); - i++; - } - } else { - try { - /* This is an expression that should evaluate to an - attribute set. Evaluate it to get the names of the - attributes. */ - std::string expr(cur, 0, dot); - std::string cur2 = std::string(cur, dot + 1); - - Expr* e = parseString(expr); - Value v; - e->eval(state, *env, v); - state.forceAttrs(v); - - for (auto& i : *v.attrs) { - std::string name = i.second.name; - if (std::string(name, 0, cur2.size()) != cur2) { - continue; - } - completions.insert(prev + expr + "." + name); - } - - } catch (ParseError& e) { - // Quietly ignore parse errors. - } catch (EvalError& e) { - // Quietly ignore evaluation errors. - } catch (UndefinedVarError& e) { - // Quietly ignore undefined variable errors. - } - } - - return completions; -} - -static int runProgram(const std::string& program, const Strings& args) { - Strings args2(args); - args2.push_front(program); - - Pid pid; - pid = fork(); - if (pid == Pid(-1)) { - throw SysError("forking"); - } - if (pid == Pid(0)) { - restoreAffinity(); - execvp(program.c_str(), stringsToCharPtrs(args2).data()); - _exit(1); - } - - return pid.wait(); -} - -bool isVarName(const std::string& s) { - if (s.empty()) { - return false; - } - char c = s[0]; - if ((c >= '0' && c <= '9') || c == '-' || c == '\'') { - return false; - } - for (auto& i : s) { - if (!((i >= 'a' && i <= 'z') || (i >= 'A' && i <= 'Z') || - (i >= '0' && i <= '9') || i == '_' || i == '-' || i == '\'')) { - return false; - } - } - return true; -} - -Path NixRepl::getDerivationPath(Value& v) { - auto drvInfo = getDerivation(state, v, false); - if (!drvInfo) { - throw Error( - "expression does not evaluate to a derivation, so I can't build it"); - } - Path drvPath = drvInfo->queryDrvPath(); - if (drvPath.empty() || !state.store->isValidPath(drvPath)) { - throw Error("expression did not evaluate to a valid derivation"); - } - return drvPath; -} - -bool NixRepl::processLine(std::string line) { - if (line.empty()) { - return true; - } - - std::string command; - std::string arg; - - if (line[0] == ':') { - size_t p = line.find_first_of(" \n\r\t"); - command = std::string(line, 0, p); - if (p != std::string::npos) { - arg = removeWhitespace(std::string(line, p)); - } - } else { - arg = line; - } - - if (command == ":?" || command == ":help") { - std::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" - << " :i <expr> Build derivation, then install result into " - "current profile\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" - << " :u <expr> Build derivation, then start nix-shell\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 == ":u") { - Value v; - Value f; - Value result; - evalString(arg, v); - evalString( - "drv: (import <nixpkgs> {}).runCommand \"shell\" { buildInputs = [ drv " - "]; } \"\"", - f); - state.callFunction(f, v, result, Pos()); - - Path drvPath = getDerivationPath(result); - runProgram(settings.nixBinDir + "/nix-shell", Strings{drvPath}); - } - - else if (command == ":b" || command == ":i" || command == ":s") { - Value v; - evalString(arg, v); - Path drvPath = getDerivationPath(v); - - 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(settings.nixBinDir + "/nix", - Strings{"build", "--no-link", drvPath}) == 0) { - Derivation drv = readDerivation(drvPath); - std::cout << std::endl - << "this derivation produced the following outputs:" - << std::endl; - for (auto& i : drv.outputs) { - std::cout << format(" %1% -> %2%") % i.first % i.second.path - << std::endl; - } - } - } else if (command == ":i") { - runProgram(settings.nixBinDir + "/nix-env", Strings{"-i", drvPath}); - } else { - runProgram(settings.nixBinDir + "/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.empty()) { - throw Error(format("unknown command '%1%'") % command); - - } else { - size_t p = line.find('='); - std::string name; - if (p != std::string::npos && p < line.size() && line[p + 1] != '=' && - isVarName(name = removeWhitespace(std::string(line, 0, p)))) { - Expr* e = parseString(std::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; - Value v2; - state.evalFile(lookupFileArg(state, path), v); - state.autoCallFunction(autoArgs.get(), v, v2); - addAttrsToScope(v2); -} - -void NixRepl::initEnv() { - env = &state.allocEnv(envSize); - env->up = &state.baseEnv; - displ = 0; - staticEnv.vars.clear(); - - varNames.clear(); - for (auto& i : state.staticBaseEnv.vars) { - varNames.insert(i.first); - } -} - -void NixRepl::reloadFiles() { - initEnv(); - - Strings old = loadedFiles; - loadedFiles.clear(); - - bool first = true; - for (auto& i : old) { - if (!first) { - std::cout << std::endl; - } - first = false; - std::cout << format("Loading '%1%'...") % i << std::endl; - loadFile(i); - } -} - -void NixRepl::addAttrsToScope(Value& attrs) { - state.forceAttrs(attrs); - for (auto& i : *attrs.attrs) { - addVarToScope(i.second.name, *i.second.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(std::string(name)); -} - -Expr* NixRepl::parseString(const std::string& s) { - Expr* e = state.parseExprFromString(s, curDir, staticEnv); - return e; -} - -void NixRepl::evalString(std::string s, Value& v) { - Expr* e = parseString(std::move(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); -} - -std::ostream& printStringValue(std::ostream& str, const char* string) { - str << "\""; - for (const char* i = string; *i != 0; 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 << "\""; - return str; -} - -// 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 << ESC_CYA << v.integer << ESC_END; - break; - - case tBool: - str << ESC_CYA << (v.boolean ? "true" : "false") << ESC_END; - break; - - case tString: - str << ESC_YEL; - printStringValue(str, v.string.s); - str << ESC_END; - break; - - case tPath: - str << ESC_GRE << v.path << ESC_END; // !!! escaping? - break; - - case tNull: - str << ESC_CYA "null" ESC_END; - 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->second.pos, *i->second.value, context) - : "???"; - str << drvPath << "»"; - } - - else if (maxDepth > 0) { - str << "{ "; - - typedef std::map<std::string, Value*> Sorted; - Sorted sorted; - for (auto& i : *v.attrs) { - sorted[i.second.name] = i.second.value; - } - - for (auto& i : sorted) { - if (isVarName(i.first)) { - str << i.first; - } else { - printStringValue(str, i.first.c_str()); - } - str << " = "; - if (seen.find(i.second) != seen.end()) { - str << "«repeated»"; - } else { - try { - printValue(str, *i.second, maxDepth - 1, seen); - } catch (AssertionError& e) { - str << ESC_RED "«error: " << e.msg() << "»" ESC_END; - } - } - str << "; "; - } - - str << "}"; - } else { - str << "{ ... }"; - } - - break; - } - - case tList: - seen.insert(&v); - - str << "[ "; - if (maxDepth > 0) { - for (unsigned int n = 0; n < v.listSize(); ++n) { - if (seen.find((*v.list)[n]) != seen.end()) { - str << "«repeated»"; - } else { - try { - printValue(str, *(*v.list)[n], maxDepth - 1, seen); - } catch (AssertionError& e) { - str << ESC_RED "«error: " << e.msg() << "»" ESC_END; - } - } - str << " "; - } - } else { - str << "... "; - } - - str << "]"; - break; - - case tLambda: { - std::ostringstream s; - s << v.lambda.fun->pos; - str << ESC_BLU "«lambda @ " << filterANSIEscapes(s.str()) << "»" ESC_END; - break; - } - - case tPrimOp: - str << ESC_MAG "«primop»" ESC_END; - break; - - case tPrimOpApp: - str << ESC_BLU "«primop-app»" ESC_END; - break; - - case tFloat: - str << v.fpoint; - break; - - default: - str << ESC_RED "«unknown»" ESC_END; - break; - } - - return str; -} - -struct CmdRepl final : StoreCommand, MixEvalArgs { - std::vector<std::string> files; - - CmdRepl() { expectArgs("files", &files); } - - std::string name() override { return "repl"; } - - std::string description() override { - return "start an interactive environment for evaluating Nix expressions"; - } - - void run(ref<Store> store) override { - auto repl = std::make_unique<NixRepl>(searchPath, openStore()); - repl->autoArgs = getAutoArgs(repl->state); - repl->mainLoop(files); - } -}; - -static RegisterCommand r1(make_ref<CmdRepl>()); - -} // namespace nix |