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#include "globals.hh"
#include "profiles.hh"
#include "eval.hh"
#include "eval-settings.hh"
namespace nix {
/* Very hacky way to parse $NIX_PATH, which is colon-separated, but
can contain URLs (e.g. "nixpkgs=https://bla...:foo=https://"). */
static Strings parseNixPath(const std::string & s)
{
Strings res;
auto p = s.begin();
while (p != s.end()) {
auto start = p;
auto start2 = p;
while (p != s.end() && *p != ':') {
if (*p == '=') start2 = p + 1;
++p;
}
if (p == s.end()) {
if (p != start) res.push_back(std::string(start, p));
break;
}
if (*p == ':') {
auto prefix = std::string(start2, s.end());
if (EvalSettings::isPseudoUrl(prefix) || hasPrefix(prefix, "flake:")) {
++p;
while (p != s.end() && *p != ':') ++p;
}
res.push_back(std::string(start, p));
if (p == s.end()) break;
}
++p;
}
return res;
}
EvalSettings::EvalSettings()
{
auto var = getEnv("NIX_PATH");
if (var) nixPath = parseNixPath(*var);
}
Strings EvalSettings::getDefaultNixPath()
{
Strings res;
auto add = [&](const Path & p, const std::string & s = std::string()) {
if (pathAccessible(p)) {
if (s.empty()) {
res.push_back(p);
} else {
res.push_back(s + "=" + p);
}
}
};
if (!evalSettings.restrictEval && !evalSettings.pureEval) {
add(getNixDefExpr() + "/channels");
add(rootChannelsDir() + "/nixpkgs", "nixpkgs");
add(rootChannelsDir());
}
return res;
}
bool EvalSettings::isPseudoUrl(std::string_view s)
{
if (s.compare(0, 8, "channel:") == 0) return true;
size_t pos = s.find("://");
if (pos == std::string::npos) return false;
std::string scheme(s, 0, pos);
return scheme == "http" || scheme == "https" || scheme == "file" || scheme == "channel" || scheme == "git" || scheme == "s3" || scheme == "ssh";
}
std::string EvalSettings::resolvePseudoUrl(std::string_view url)
{
if (hasPrefix(url, "channel:"))
return "https://nixos.org/channels/" + std::string(url.substr(8)) + "/nixexprs.tar.xz";
else
return std::string(url);
}
EvalSettings evalSettings;
static GlobalConfig::Register rEvalSettings(&evalSettings);
Path getNixDefExpr()
{
return settings.useXDGBaseDirectories
? getStateDir() + "/nix/defexpr"
: getHome() + "/.nix-defexpr";
}
}
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