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#include "flakeref.hh"
#include <regex>
namespace nix {
// A Git ref (i.e. branch or tag name).
const static std::string refRegex = "[a-zA-Z0-9][a-zA-Z0-9_.-]*"; // FIXME: check
// A Git revision (a SHA-1 commit hash).
const static std::string revRegexS = "[0-9a-fA-F]{40}";
std::regex revRegex(revRegexS, std::regex::ECMAScript);
// A Git ref or revision.
const static std::string revOrRefRegex = "(?:(" + revRegexS + ")|(" + refRegex + "))";
// A rev ("e72daba8250068216d79d2aeef40d4d95aff6666"), or a ref
// optionally followed by a rev (e.g. "master" or
// "master/e72daba8250068216d79d2aeef40d4d95aff6666").
const static std::string refAndOrRevRegex = "(?:(" + revRegexS + ")|(?:(" + refRegex + ")(?:/(" + revRegexS + "))?))";
const static std::string flakeAlias = "[a-zA-Z][a-zA-Z0-9_-]*";
// GitHub references.
const static std::string ownerRegex = "[a-zA-Z][a-zA-Z0-9_-]*";
const static std::string repoRegex = "[a-zA-Z][a-zA-Z0-9_-]*";
// URI stuff.
const static std::string schemeRegex = "(?:http|https|ssh|git|file)";
const static std::string authorityRegex = "[a-zA-Z0-9._~-]*";
const static std::string segmentRegex = "[a-zA-Z0-9._~-]+";
const static std::string pathRegex = "/?" + segmentRegex + "(?:/" + segmentRegex + ")*";
// FIXME: support escaping in query string.
// Note: '/' is not a valid query parameter, but so what...
const static std::string paramRegex = "[a-z]+=[/a-zA-Z0-9._-]*";
const static std::string paramsRegex = "(?:[?](" + paramRegex + "(?:&" + paramRegex + ")*))";
// 'dir' path elements cannot start with a '.'. We also reject
// potentially dangerous characters like ';'.
const static std::string subDirElemRegex = "(?:[a-zA-Z0-9_-]+[a-zA-Z0-9._-]*)";
const static std::string subDirRegex = subDirElemRegex + "(?:/" + subDirElemRegex + ")*";
FlakeRef::FlakeRef(const std::string & uri, bool allowRelative)
{
// FIXME: could combine this into one regex.
static std::regex flakeRegex(
"(?:flake:)?(" + flakeAlias + ")(?:/(?:" + refAndOrRevRegex + "))?",
std::regex::ECMAScript);
static std::regex githubRegex(
"github:(" + ownerRegex + ")/(" + repoRegex + ")(?:/" + revOrRefRegex + ")?"
+ paramsRegex + "?",
std::regex::ECMAScript);
static std::regex uriRegex(
"((" + schemeRegex + "):" +
"(?://(" + authorityRegex + "))?" +
"(" + pathRegex + "))" +
paramsRegex + "?",
std::regex::ECMAScript);
static std::regex refRegex2(refRegex, std::regex::ECMAScript);
static std::regex subDirRegex2(subDirRegex, std::regex::ECMAScript);
std::cmatch match;
if (std::regex_match(uri.c_str(), match, flakeRegex)) {
IsAlias d;
d.alias = match[1];
if (match[2].matched)
rev = Hash(match[2], htSHA1);
else if (match[3].matched) {
ref = match[3];
if (match[4].matched)
rev = Hash(match[4], htSHA1);
}
data = d;
}
else if (std::regex_match(uri.c_str(), match, githubRegex)) {
IsGitHub d;
d.owner = match[1];
d.repo = match[2];
if (match[3].matched)
rev = Hash(match[3], htSHA1);
else if (match[4].matched) {
ref = match[4];
}
for (auto & param : tokenizeString<Strings>(match[5], "&")) {
auto n = param.find('=');
assert(n != param.npos);
std::string name(param, 0, n);
std::string value(param, n + 1);
if (name == "dir") {
if (value != "" && !std::regex_match(value, subDirRegex2))
throw Error("flake '%s' has invalid subdirectory '%s'", uri, value);
subdir = value;
} else
throw Error("invalid Git flake reference parameter '%s', in '%s'", name, uri);
}
data = d;
}
else if (std::regex_match(uri.c_str(), match, uriRegex)
&& (match[2] == "file" || hasSuffix(match[4], ".git")))
{
IsGit d;
d.uri = match[1];
for (auto & param : tokenizeString<Strings>(match[5], "&")) {
auto n = param.find('=');
assert(n != param.npos);
std::string name(param, 0, n);
std::string value(param, n + 1);
if (name == "rev") {
if (!std::regex_match(value, revRegex))
throw Error("invalid Git revision '%s'", value);
rev = Hash(value, htSHA1);
} else if (name == "ref") {
if (!std::regex_match(value, refRegex2))
throw Error("invalid Git ref '%s'", value);
ref = value;
} else if (name == "dir") {
if (value != "" && !std::regex_match(value, subDirRegex2))
throw Error("flake '%s' has invalid subdirectory '%s'", uri, value);
subdir = value;
} else
// FIXME: should probably pass through unknown parameters
throw Error("invalid Git flake reference parameter '%s', in '%s'", name, uri);
}
if (rev && !ref)
throw Error("flake URI '%s' lacks a Git ref", uri);
data = d;
}
else if (hasPrefix(uri, "/") || (allowRelative && (hasPrefix(uri, "./") || uri == "."))) {
IsPath d;
d.path = allowRelative ? absPath(uri) : canonPath(uri);
data = d;
}
else
throw Error("'%s' is not a valid flake reference", uri);
}
std::string FlakeRef::to_string() const
{
std::string string;
bool first = true;
auto addParam =
[&](const std::string & name, std::string value) {
string += first ? '?' : '&';
first = false;
string += name;
string += '=';
string += value; // FIXME: escaping
};
if (auto refData = std::get_if<FlakeRef::IsAlias>(&data)) {
string = refData->alias;
if (ref) string += '/' + *ref;
if (rev) string += '/' + rev->to_string(Base16, false);
}
else if (auto refData = std::get_if<FlakeRef::IsPath>(&data)) {
assert(subdir == "");
assert(!rev);
assert(!ref);
return refData->path;
}
else if (auto refData = std::get_if<FlakeRef::IsGitHub>(&data)) {
assert(!(ref && rev));
string = "github:" + refData->owner + "/" + refData->repo;
if (ref) { string += '/'; string += *ref; }
if (rev) { string += '/'; string += rev->to_string(Base16, false); }
if (subdir != "") addParam("dir", subdir);
}
else if (auto refData = std::get_if<FlakeRef::IsGit>(&data)) {
assert(!rev || ref);
string = refData->uri;
if (ref) {
addParam("ref", *ref);
if (rev)
addParam("rev", rev->to_string(Base16, false));
}
if (subdir != "") addParam("dir", subdir);
}
else abort();
return string;
}
std::ostream & operator << (std::ostream & str, const FlakeRef & flakeRef)
{
str << flakeRef.to_string();
return str;
}
bool FlakeRef::isImmutable() const
{
return (bool) rev;
}
FlakeRef FlakeRef::baseRef() const // Removes the ref and rev from a FlakeRef.
{
FlakeRef result(*this);
result.ref = std::nullopt;
result.rev = std::nullopt;
return result;
}
}
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