#include "libstore/derivations.hh"
#include <absl/strings/match.h>
#include <absl/strings/str_split.h>
#include <absl/strings/string_view.h>
#include "libstore/fs-accessor.hh"
#include "libstore/globals.hh"
#include "libstore/store-api.hh"
#include "libstore/worker-protocol.hh"
#include "libutil/istringstream_nocopy.hh"
#include "libutil/util.hh"
namespace nix {
void DerivationOutput::parseHashInfo(bool& recursive, Hash& hash) const {
recursive = false;
std::string algo = hashAlgo;
if (std::string(algo, 0, 2) == "r:") {
recursive = true;
algo = std::string(algo, 2);
}
HashType hashType = parseHashType(algo);
if (hashType == htUnknown) {
throw Error(format("unknown hash algorithm '%1%'") % algo);
}
hash = Hash(this->hash, hashType);
}
BasicDerivation BasicDerivation::from_proto(
const nix::proto::Derivation* proto_derivation, const nix::Store& store) {
BasicDerivation result;
result.platform = proto_derivation->platform();
result.builder = proto_derivation->builder().path();
store.assertStorePath(result.builder);
result.outputs.insert(proto_derivation->outputs().begin(),
proto_derivation->outputs().end());
result.inputSrcs.insert(proto_derivation->input_sources().paths().begin(),
proto_derivation->input_sources().paths().end());
result.args.insert(result.args.end(), proto_derivation->args().begin(),
proto_derivation->args().end());
result.env.insert(proto_derivation->env().begin(),
proto_derivation->env().end());
return result;
}
Path BasicDerivation::findOutput(const std::string& id) const {
auto i = outputs.find(id);
if (i == outputs.end()) {
throw Error(format("derivation has no output '%1%'") % id);
}
return i->second.path;
}
bool BasicDerivation::isBuiltin() const {
return std::string(builder, 0, 8) == "builtin:";
}
Path writeDerivation(const ref<Store>& store, const Derivation& drv,
const std::string& name, RepairFlag repair) {
PathSet references;
references.insert(drv.inputSrcs.begin(), drv.inputSrcs.end());
for (auto& i : drv.inputDrvs) {
references.insert(i.first);
}
/* Note that the outputs of a derivation are *not* references
(that can be missing (of course) and should not necessarily be
held during a garbage collection). */
std::string suffix = name + drvExtension;
std::string contents = drv.unparse();
return settings.readOnlyMode
? store->computeStorePathForText(suffix, contents, references)
: store->addTextToStore(suffix, contents, references, repair);
}
/* Read string `s' from stream `str'. */
static void expect(std::istream& str, const std::string& s) {
char s2[s.size()];
str.read(s2, s.size());
if (std::string(s2, s.size()) != s) {
throw FormatError(format("expected string '%1%'") % s);
}
}
/* Read a C-style string from stream `str'. */
static std::string parseString(std::istream& str) {
std::string res;
expect(str, "\"");
int c = 0;
while ((c = str.get()) != '"') {
if (c == '\\') {
c = str.get();
if (c == 'n') {
res += '\n';
} else if (c == 'r') {
res += '\r';
} else if (c == 't') {
res += '\t';
} else {
res += std::to_string(c);
}
} else {
res += std::to_string(c);
}
}
return res;
}
static Path parsePath(std::istream& str) {
std::string s = parseString(str);
if (s.empty() || s[0] != '/') {
throw FormatError(format("bad path '%1%' in derivation") % s);
}
return s;
}
static bool endOfList(std::istream& str) {
if (str.peek() == ',') {
str.get();
return false;
}
if (str.peek() == ']') {
str.get();
return true;
}
return false;
}
static StringSet parseStrings(std::istream& str, bool arePaths) {
StringSet res;
while (!endOfList(str)) {
res.insert(arePaths ? parsePath(str) : parseString(str));
}
return res;
}
static Derivation parseDerivation(const std::string& s) {
Derivation drv;
istringstream_nocopy str(s);
expect(str, "Derive([");
/* Parse the list of outputs. */
while (!endOfList(str)) {
DerivationOutput out;
expect(str, "(");
std::string id = parseString(str);
expect(str, ",");
out.path = parsePath(str);
expect(str, ",");
out.hashAlgo = parseString(str);
expect(str, ",");
out.hash = parseString(str);
expect(str, ")");
drv.outputs[id] = out;
}
/* Parse the list of input derivations. */
expect(str, ",[");
while (!endOfList(str)) {
expect(str, "(");
Path drvPath = parsePath(str);
expect(str, ",[");
drv.inputDrvs[drvPath] = parseStrings(str, false);
expect(str, ")");
}
expect(str, ",[");
drv.inputSrcs = parseStrings(str, true);
expect(str, ",");
drv.platform = parseString(str);
expect(str, ",");
drv.builder = parseString(str);
/* Parse the builder arguments. */
expect(str, ",[");
while (!endOfList(str)) {
drv.args.push_back(parseString(str));
}
/* Parse the environment variables. */
expect(str, ",[");
while (!endOfList(str)) {
expect(str, "(");
std::string name = parseString(str);
expect(str, ",");
std::string value = parseString(str);
expect(str, ")");
drv.env[name] = value;
}
expect(str, ")");
return drv;
}
Derivation readDerivation(const Path& drvPath) {
try {
return parseDerivation(readFile(drvPath));
} catch (FormatError& e) {
throw Error(format("error parsing derivation '%1%': %2%") % drvPath %
e.msg());
}
}
Derivation Store::derivationFromPath(const Path& drvPath) {
assertStorePath(drvPath);
ensurePath(drvPath);
auto accessor = getFSAccessor();
try {
return parseDerivation(accessor->readFile(drvPath));
} catch (FormatError& e) {
throw Error(format("error parsing derivation '%1%': %2%") % drvPath %
e.msg());
}
}
const char* findChunk(const char* begin) {
while (*begin != 0 && *begin != '\"' && *begin != '\\' && *begin != '\n' &&
*begin != '\r' && *begin != '\t') {
begin++;
}
return begin;
}
static void printString(std::string& res, const std::string& s) {
res += '"';
const char* it = s.c_str();
while (*it != 0) {
const char* end = findChunk(it);
std::copy(it, end, std::back_inserter(res));
it = end;
switch (*it) {
case '"':
case '\\':
res += "\\";
res += *it;
break;
case '\n':
res += "\\n";
break;
case '\r':
res += "\\r";
break;
case '\t':
res += "\\t";
break;
default:
continue;
}
it++;
}
res += '"';
}
template <class ForwardIterator>
static void printStrings(std::string& res, ForwardIterator i,
ForwardIterator j) {
res += '[';
bool first = true;
for (; i != j; ++i) {
if (first) {
first = false;
} else {
res += ',';
}
printString(res, *i);
}
res += ']';
}
std::string Derivation::unparse() const {
std::string s;
s.reserve(65536);
s += "Derive([";
bool first = true;
for (auto& i : outputs) {
if (first) {
first = false;
} else {
s += ',';
}
s += '(';
printString(s, i.first);
s += ',';
printString(s, i.second.path);
s += ',';
printString(s, i.second.hashAlgo);
s += ',';
printString(s, i.second.hash);
s += ')';
}
s += "],[";
first = true;
for (auto& i : inputDrvs) {
if (first) {
first = false;
} else {
s += ',';
}
s += '(';
printString(s, i.first);
s += ',';
printStrings(s, i.second.begin(), i.second.end());
s += ')';
}
s += "],";
printStrings(s, inputSrcs.begin(), inputSrcs.end());
s += ',';
printString(s, platform);
s += ',';
printString(s, builder);
s += ',';
printStrings(s, args.begin(), args.end());
s += ",[";
first = true;
for (auto& i : env) {
if (first) {
first = false;
} else {
s += ',';
}
s += '(';
printString(s, i.first);
s += ',';
printString(s, i.second);
s += ')';
}
s += "])";
return s;
}
bool isDerivation(const std::string& fileName) {
return absl::EndsWith(fileName, drvExtension);
}
bool BasicDerivation::isFixedOutput() const {
return outputs.size() == 1 && outputs.begin()->first == "out" &&
!outputs.begin()->second.hash.empty();
}
DrvHashes drvHashes;
/* Returns the hash of a derivation modulo fixed-output
subderivations. A fixed-output derivation is a derivation with one
output (`out') for which an expected hash and hash algorithm are
specified (using the `outputHash' and `outputHashAlgo'
attributes). We don't want changes to such derivations to
propagate upwards through the dependency graph, changing output
paths everywhere.
For instance, if we change the url in a call to the `fetchurl'
function, we do not want to rebuild everything depending on it
(after all, (the hash of) the file being downloaded is unchanged).
So the *output paths* should not change. On the other hand, the
*derivation paths* should change to reflect the new dependency
graph.
That's what this function does: it returns a hash which is just the
hash of the derivation ATerm, except that any input derivation
paths have been replaced by the result of a recursive call to this
function, and that for fixed-output derivations we return a hash of
its output path. */
Hash hashDerivationModulo(Store& store, Derivation drv) {
/* Return a fixed hash for fixed-output derivations. */
if (drv.isFixedOutput()) {
auto i = drv.outputs.begin();
return hashString(htSHA256, "fixed:out:" + i->second.hashAlgo + ":" +
i->second.hash + ":" + i->second.path);
}
/* For other derivations, replace the inputs paths with recursive
calls to this function.*/
DerivationInputs inputs2;
for (auto& i : drv.inputDrvs) {
Hash h = drvHashes[i.first];
if (!h) {
assert(store.isValidPath(i.first));
Derivation drv2 = readDerivation(store.toRealPath(i.first));
h = hashDerivationModulo(store, drv2);
drvHashes[i.first] = h;
}
inputs2[h.to_string(Base16, false)] = i.second;
}
drv.inputDrvs = inputs2;
return hashString(htSHA256, drv.unparse());
}
// TODO(tazjin): doc comment?
DrvPathWithOutputs parseDrvPathWithOutputs(absl::string_view path) {
auto pos = path.find('!');
if (pos == absl::string_view::npos) {
return DrvPathWithOutputs(path, std::set<std::string>());
}
return DrvPathWithOutputs(path.substr(pos + 1),
absl::StrSplit(path, absl::ByChar(',')));
}
Path makeDrvPathWithOutputs(const Path& drvPath,
const std::set<std::string>& outputs) {
return outputs.empty() ? drvPath
: drvPath + "!" + concatStringsSep(",", outputs);
}
bool wantOutput(const std::string& output,
const std::set<std::string>& wanted) {
return wanted.empty() || wanted.find(output) != wanted.end();
}
PathSet BasicDerivation::outputPaths() const {
PathSet paths;
for (auto& i : outputs) {
paths.insert(i.second.path);
}
return paths;
}
Source& readDerivation(Source& in, Store& store, BasicDerivation& drv) {
drv.outputs.clear();
auto nr = readNum<size_t>(in);
for (size_t n = 0; n < nr; n++) {
auto name = readString(in);
DerivationOutput o;
in >> o.path >> o.hashAlgo >> o.hash;
store.assertStorePath(o.path);
drv.outputs[name] = o;
}
drv.inputSrcs = readStorePaths<PathSet>(store, in);
in >> drv.platform >> drv.builder;
drv.args = readStrings<Strings>(in);
nr = readNum<size_t>(in);
for (size_t n = 0; n < nr; n++) {
auto key = readString(in);
auto value = readString(in);
drv.env[key] = value;
}
return in;
}
Sink& operator<<(Sink& out, const BasicDerivation& drv) {
out << drv.outputs.size();
for (auto& i : drv.outputs) {
out << i.first << i.second.path << i.second.hashAlgo << i.second.hash;
}
out << drv.inputSrcs << drv.platform << drv.builder << drv.args;
out << drv.env.size();
for (auto& i : drv.env) {
out << i.first << i.second;
}
return out;
}
std::string hashPlaceholder(const std::string& outputName) {
// FIXME: memoize?
return "/" + hashString(htSHA256, "nix-output:" + outputName)
.to_string(Base32, false);
}
} // namespace nix
