diff options
Diffstat (limited to 'third_party/nix/src/libstore/derivations.cc')
| -rw-r--r-- | third_party/nix/src/libstore/derivations.cc | 416 |
1 files changed, 416 insertions, 0 deletions
diff --git a/third_party/nix/src/libstore/derivations.cc b/third_party/nix/src/libstore/derivations.cc new file mode 100644 index 0000000000..23fcfb281a --- /dev/null +++ b/third_party/nix/src/libstore/derivations.cc @@ -0,0 +1,416 @@ +#include "derivations.hh" +#include "store-api.hh" +#include "globals.hh" +#include "util.hh" +#include "worker-protocol.hh" +#include "fs-accessor.hh" +#include "istringstream_nocopy.hh" + +namespace nix { + + +void DerivationOutput::parseHashInfo(bool & recursive, Hash & hash) const +{ + recursive = false; + string algo = hashAlgo; + + if (string(algo, 0, 2) == "r:") { + recursive = true; + algo = string(algo, 2); + } + + HashType hashType = parseHashType(algo); + if (hashType == htUnknown) + throw Error(format("unknown hash algorithm '%1%'") % algo); + + hash = Hash(this->hash, hashType); +} + + +Path BasicDerivation::findOutput(const 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 string(builder, 0, 8) == "builtin:"; +} + + +Path writeDerivation(ref<Store> store, + const Derivation & drv, const 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). */ + string suffix = name + drvExtension; + 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 string & s) +{ + char s2[s.size()]; + str.read(s2, s.size()); + if (string(s2, s.size()) != s) + throw FormatError(format("expected string '%1%'") % s); +} + + +/* Read a C-style string from stream `str'. */ +static string parseString(std::istream & str) +{ + string res; + expect(str, "\""); + int c; + 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 += c; + } + else res += c; + return res; +} + + +static Path parsePath(std::istream & str) +{ + string s = parseString(str); + if (s.size() == 0 || 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 string & s) +{ + Derivation drv; + istringstream_nocopy str(s); + expect(str, "Derive(["); + + /* Parse the list of outputs. */ + while (!endOfList(str)) { + DerivationOutput out; + expect(str, "("); 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, "("); string name = parseString(str); + expect(str, ","); 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()); + } +} + + +static void printString(string & res, const string & s) +{ + res += '"'; + for (const char * i = s.c_str(); *i; i++) + if (*i == '\"' || *i == '\\') { res += "\\"; res += *i; } + else if (*i == '\n') res += "\\n"; + else if (*i == '\r') res += "\\r"; + else if (*i == '\t') res += "\\t"; + else res += *i; + res += '"'; +} + + +template<class ForwardIterator> +static void printStrings(string & res, ForwardIterator i, ForwardIterator j) +{ + res += '['; + bool first = true; + for ( ; i != j; ++i) { + if (first) first = false; else res += ','; + printString(res, *i); + } + res += ']'; +} + + +string Derivation::unparse() const +{ + 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 string & fileName) +{ + return hasSuffix(fileName, drvExtension); +} + + +bool BasicDerivation::isFixedOutput() const +{ + return outputs.size() == 1 && + outputs.begin()->first == "out" && + outputs.begin()->second.hash != ""; +} + + +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()) { + DerivationOutputs::const_iterator 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()); +} + + +DrvPathWithOutputs parseDrvPathWithOutputs(const string & s) +{ + size_t n = s.find("!"); + return n == s.npos + ? DrvPathWithOutputs(s, std::set<string>()) + : DrvPathWithOutputs(string(s, 0, n), tokenizeString<std::set<string> >(string(s, n + 1), ",")); +} + + +Path makeDrvPathWithOutputs(const Path & drvPath, const std::set<string> & outputs) +{ + return outputs.empty() + ? drvPath + : drvPath + "!" + concatStringsSep(",", outputs); +} + + +bool wantOutput(const string & output, const std::set<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); +} + + +} |