lix/src/libutil/args.cc
Naïm Favier 711b2e1f48
Fix flake input completion for InstallablesCommands
Defers completion of flake inputs until the whole command line is parsed
so that we know what flakes we need to complete the inputs of.

Previously, `nix build flake --update-input <Tab>` always behaved like
`nix build . --update-input <Tab>`.
2022-07-11 15:13:51 +02:00

392 lines
12 KiB
C++

#include "args.hh"
#include "hash.hh"
#include <glob.h>
#include <nlohmann/json.hpp>
namespace nix {
void Args::addFlag(Flag && flag_)
{
auto flag = std::make_shared<Flag>(std::move(flag_));
if (flag->handler.arity != ArityAny)
assert(flag->handler.arity == flag->labels.size());
assert(flag->longName != "");
longFlags[flag->longName] = flag;
for (auto & alias : flag->aliases)
longFlags[alias] = flag;
if (flag->shortName) shortFlags[flag->shortName] = flag;
}
void Args::removeFlag(const std::string & longName)
{
auto flag = longFlags.find(longName);
assert(flag != longFlags.end());
if (flag->second->shortName) shortFlags.erase(flag->second->shortName);
longFlags.erase(flag);
}
void Completions::add(std::string completion, std::string description)
{
assert(description.find('\n') == std::string::npos);
insert(Completion {
.completion = completion,
.description = description
});
}
bool Completion::operator<(const Completion & other) const
{ return completion < other.completion || (completion == other.completion && description < other.description); }
CompletionType completionType = ctNormal;
std::shared_ptr<Completions> completions;
std::string completionMarker = "___COMPLETE___";
std::optional<std::string> needsCompletion(std::string_view s)
{
if (!completions) return {};
auto i = s.find(completionMarker);
if (i != std::string::npos)
return std::string(s.begin(), i);
return {};
}
void Args::parseCmdline(const Strings & _cmdline)
{
Strings pendingArgs;
bool dashDash = false;
Strings cmdline(_cmdline);
if (auto s = getEnv("NIX_GET_COMPLETIONS")) {
size_t n = std::stoi(*s);
assert(n > 0 && n <= cmdline.size());
*std::next(cmdline.begin(), n - 1) += completionMarker;
completions = std::make_shared<decltype(completions)::element_type>();
verbosity = lvlError;
}
bool argsSeen = false;
for (auto pos = cmdline.begin(); pos != cmdline.end(); ) {
auto arg = *pos;
/* Expand compound dash options (i.e., `-qlf' -> `-q -l -f',
`-j3` -> `-j 3`). */
if (!dashDash && arg.length() > 2 && arg[0] == '-' && arg[1] != '-' && isalpha(arg[1])) {
*pos = (std::string) "-" + arg[1];
auto next = pos; ++next;
for (unsigned int j = 2; j < arg.length(); j++)
if (isalpha(arg[j]))
cmdline.insert(next, (std::string) "-" + arg[j]);
else {
cmdline.insert(next, std::string(arg, j));
break;
}
arg = *pos;
}
if (!dashDash && arg == "--") {
dashDash = true;
++pos;
}
else if (!dashDash && std::string(arg, 0, 1) == "-") {
if (!processFlag(pos, cmdline.end()))
throw UsageError("unrecognised flag '%1%'", arg);
}
else {
if (!argsSeen) {
argsSeen = true;
initialFlagsProcessed();
}
pos = rewriteArgs(cmdline, pos);
pendingArgs.push_back(*pos++);
if (processArgs(pendingArgs, false))
pendingArgs.clear();
}
}
processArgs(pendingArgs, true);
if (!argsSeen)
initialFlagsProcessed();
}
bool Args::processFlag(Strings::iterator & pos, Strings::iterator end)
{
assert(pos != end);
auto process = [&](const std::string & name, const Flag & flag) -> bool {
++pos;
std::vector<std::string> args;
bool anyCompleted = false;
for (size_t n = 0 ; n < flag.handler.arity; ++n) {
if (pos == end) {
if (flag.handler.arity == ArityAny || anyCompleted) break;
throw UsageError("flag '%s' requires %d argument(s)", name, flag.handler.arity);
}
if (auto prefix = needsCompletion(*pos)) {
anyCompleted = true;
if (flag.completer)
flag.completer(n, *prefix);
}
args.push_back(*pos++);
}
if (!anyCompleted)
flag.handler.fun(std::move(args));
return true;
};
if (std::string(*pos, 0, 2) == "--") {
if (auto prefix = needsCompletion(*pos)) {
for (auto & [name, flag] : longFlags) {
if (!hiddenCategories.count(flag->category)
&& hasPrefix(name, std::string(*prefix, 2)))
completions->add("--" + name, flag->description);
}
return false;
}
auto i = longFlags.find(std::string(*pos, 2));
if (i == longFlags.end()) return false;
return process("--" + i->first, *i->second);
}
if (std::string(*pos, 0, 1) == "-" && pos->size() == 2) {
auto c = (*pos)[1];
auto i = shortFlags.find(c);
if (i == shortFlags.end()) return false;
return process(std::string("-") + c, *i->second);
}
if (auto prefix = needsCompletion(*pos)) {
if (prefix == "-") {
completions->add("--");
for (auto & [flagName, flag] : shortFlags)
completions->add(std::string("-") + flagName, flag->description);
}
}
return false;
}
bool Args::processArgs(const Strings & args, bool finish)
{
if (expectedArgs.empty()) {
if (!args.empty())
throw UsageError("unexpected argument '%1%'", args.front());
return true;
}
auto & exp = expectedArgs.front();
bool res = false;
if ((exp.handler.arity == ArityAny && finish) ||
(exp.handler.arity != ArityAny && args.size() == exp.handler.arity))
{
std::vector<std::string> ss;
for (const auto &[n, s] : enumerate(args)) {
if (auto prefix = needsCompletion(s)) {
ss.push_back(*prefix);
if (exp.completer)
exp.completer(n, *prefix);
} else
ss.push_back(s);
}
exp.handler.fun(ss);
expectedArgs.pop_front();
res = true;
}
if (finish && !expectedArgs.empty() && !expectedArgs.front().optional)
throw UsageError("more arguments are required");
return res;
}
nlohmann::json Args::toJSON()
{
auto flags = nlohmann::json::object();
for (auto & [name, flag] : longFlags) {
auto j = nlohmann::json::object();
if (flag->aliases.count(name)) continue;
if (flag->shortName)
j["shortName"] = std::string(1, flag->shortName);
if (flag->description != "")
j["description"] = flag->description;
j["category"] = flag->category;
if (flag->handler.arity != ArityAny)
j["arity"] = flag->handler.arity;
if (!flag->labels.empty())
j["labels"] = flag->labels;
flags[name] = std::move(j);
}
auto args = nlohmann::json::array();
for (auto & arg : expectedArgs) {
auto j = nlohmann::json::object();
j["label"] = arg.label;
j["optional"] = arg.optional;
if (arg.handler.arity != ArityAny)
j["arity"] = arg.handler.arity;
args.push_back(std::move(j));
}
auto res = nlohmann::json::object();
res["description"] = description();
res["flags"] = std::move(flags);
res["args"] = std::move(args);
auto s = doc();
if (s != "") res.emplace("doc", stripIndentation(s));
return res;
}
static void hashTypeCompleter(size_t index, std::string_view prefix)
{
for (auto & type : hashTypes)
if (hasPrefix(type, prefix))
completions->add(type);
}
Args::Flag Args::Flag::mkHashTypeFlag(std::string && longName, HashType * ht)
{
return Flag {
.longName = std::move(longName),
.description = "hash algorithm ('md5', 'sha1', 'sha256', or 'sha512')",
.labels = {"hash-algo"},
.handler = {[ht](std::string s) {
*ht = parseHashType(s);
}},
.completer = hashTypeCompleter
};
}
Args::Flag Args::Flag::mkHashTypeOptFlag(std::string && longName, std::optional<HashType> * oht)
{
return Flag {
.longName = std::move(longName),
.description = "hash algorithm ('md5', 'sha1', 'sha256', or 'sha512'). Optional as can also be gotten from SRI hash itself.",
.labels = {"hash-algo"},
.handler = {[oht](std::string s) {
*oht = std::optional<HashType> { parseHashType(s) };
}},
.completer = hashTypeCompleter
};
}
static void _completePath(std::string_view prefix, bool onlyDirs)
{
completionType = ctFilenames;
glob_t globbuf;
int flags = GLOB_NOESCAPE;
#ifdef GLOB_ONLYDIR
if (onlyDirs)
flags |= GLOB_ONLYDIR;
#endif
// using expandTilde here instead of GLOB_TILDE(_CHECK) so that ~<Tab> expands to /home/user/
if (glob((expandTilde(prefix) + "*").c_str(), flags, nullptr, &globbuf) == 0) {
for (size_t i = 0; i < globbuf.gl_pathc; ++i) {
if (onlyDirs) {
auto st = stat(globbuf.gl_pathv[i]);
if (!S_ISDIR(st.st_mode)) continue;
}
completions->add(globbuf.gl_pathv[i]);
}
}
globfree(&globbuf);
}
void completePath(size_t, std::string_view prefix)
{
_completePath(prefix, false);
}
void completeDir(size_t, std::string_view prefix)
{
_completePath(prefix, true);
}
Strings argvToStrings(int argc, char * * argv)
{
Strings args;
argc--; argv++;
while (argc--) args.push_back(*argv++);
return args;
}
MultiCommand::MultiCommand(const Commands & commands_)
: commands(commands_)
{
expectArgs({
.label = "subcommand",
.optional = true,
.handler = {[=](std::string s) {
assert(!command);
auto i = commands.find(s);
if (i == commands.end()) {
std::set<std::string> commandNames;
for (auto & [name, _] : commands)
commandNames.insert(name);
auto suggestions = Suggestions::bestMatches(commandNames, s);
throw UsageError(suggestions, "'%s' is not a recognised command", s);
}
command = {s, i->second()};
command->second->parent = this;
}},
.completer = {[&](size_t, std::string_view prefix) {
for (auto & [name, command] : commands)
if (hasPrefix(name, prefix))
completions->add(name);
}}
});
categories[Command::catDefault] = "Available commands";
}
bool MultiCommand::processFlag(Strings::iterator & pos, Strings::iterator end)
{
if (Args::processFlag(pos, end)) return true;
if (command && command->second->processFlag(pos, end)) return true;
return false;
}
bool MultiCommand::processArgs(const Strings & args, bool finish)
{
if (command)
return command->second->processArgs(args, finish);
else
return Args::processArgs(args, finish);
}
void MultiCommand::completionHook()
{
if (command)
return command->second->completionHook();
else
return Args::completionHook();
}
nlohmann::json MultiCommand::toJSON()
{
auto cmds = nlohmann::json::object();
for (auto & [name, commandFun] : commands) {
auto command = commandFun();
auto j = command->toJSON();
auto cat = nlohmann::json::object();
cat["id"] = command->category();
cat["description"] = categories[command->category()];
j["category"] = std::move(cat);
cmds[name] = std::move(j);
}
auto res = Args::toJSON();
res["commands"] = std::move(cmds);
return res;
}
}