diff options
| -rw-r--r-- | src/libstore/build.cc | 78 |
1 files changed, 67 insertions, 11 deletions
diff --git a/src/libstore/build.cc b/src/libstore/build.cc index 4be46cfd34fc..93dfd21ccec2 100644 --- a/src/libstore/build.cc +++ b/src/libstore/build.cc @@ -731,6 +731,26 @@ HookInstance::~HookInstance() ////////////////////////////////////////////////////////////////////// +typedef map<string, string> HashRewrites; + + +string rewriteHashes(string s, const HashRewrites & rewrites) +{ + foreach (HashRewrites::const_iterator, i, rewrites) { + assert(i->first.size() == i->second.size()); + size_t j = 0; + while ((j = s.find(i->first, j)) != string::npos) { + debug(format("rewriting @ %1%") % j); + s.replace(j, i->second.size(), i->second); + } + } + return s; +} + + +////////////////////////////////////////////////////////////////////// + + typedef enum {rpAccept, rpDecline, rpPostpone} HookReply; class SubstitutionGoal; @@ -801,6 +821,10 @@ private: typedef map<string, string> Environment; Environment env; + /* Hash rewriting. */ + HashRewrites rewritesToTmp, rewritesFromTmp; + PathSet redirectedOutputs; + public: DerivationGoal(const Path & drvPath, Worker & worker); ~DerivationGoal(); @@ -1277,14 +1301,13 @@ void DerivationGoal::buildDone() foreach (DerivationOutputs::iterator, i, drv.outputs) { Path path = i->second.path; - if (useChroot && pathExists(chrootRootDir + path)) { - /* Move output paths from the chroot to the Nix store. - If the output was already valid, just skip - (discard) it. */ - if (validPaths.find(path) != validPaths.end()) continue; + /* If the output was already valid, just skip (discard) it. */ + if (validPaths.find(path) != validPaths.end()) continue; + + if (useChroot && pathExists(chrootRootDir + path)) + /* Move output paths from the chroot to the Nix store. */ if (rename((chrootRootDir + path).c_str(), path.c_str()) == -1) throw SysError(format("moving build output `%1%' from the chroot to the Nix store") % path); - } if (!pathExists(path)) continue; @@ -1302,6 +1325,17 @@ void DerivationGoal::buildDone() throw BuildError(format("suspicious ownership or permission on `%1%'; rejecting this build output") % path); #endif + /* Apply hash rewriting if necessary. */ + if (!rewritesFromTmp.empty()) { + printMsg(lvlError, format("warning: rewriting hashes in `%1%'; cross fingers") % path); + /* FIXME: this is in-memory. */ + StringSink sink; + dumpPath(path, sink); + deletePath(path); + StringSource source(rewriteHashes(sink.s, rewritesFromTmp)); + restorePath(path, source); + } + /* Gain ownership of the build result using the setuid wrapper if we're not root. If we *are* root, then canonicalisePathMetaData() will take care of this later @@ -1327,6 +1361,10 @@ void DerivationGoal::buildDone() foreach (PathSet::iterator, i, regularInputPaths) makeImmutable(*i); + /* Delete redirected outputs (when doing hash rewriting). */ + foreach (PathSet::iterator, i, redirectedOutputs) + deletePath(*i); + /* Compute the FS closure of the outputs and register them as being valid. */ computeClosure(); @@ -1746,9 +1784,27 @@ void DerivationGoal::startBuilder() #else throw Error("chroot builds are not supported on this platform"); #endif - } else { // !useChroot - if (validPaths.size() > 0) - throw Error(format("derivation `%1%' is blocked by its output path(s) %2%") % drvPath % showPaths(validPaths)); + } + + /* We're not doing a chroot build, but we have some valid output + paths. Since we can't just overwrite or delete them, we have + to do hash rewriting: i.e. in the environment/arguments passed + to the build, we replace the hashes of the valid outputs with + unique dummy strings; after the build, we discard the + redirected outputs corresponding to the valid outputs, and + rewrite the contents of the new outputs to replace the dummy + strings with the actual hashes. */ + else if (validPaths.size() > 0) { + //throw Error(format("derivation `%1%' is blocked by its output path(s) %2%") % drvPath % showPaths(validPaths)); + foreach (PathSet::iterator, i, validPaths) { + string h1 = string(*i, settings.nixStore.size() + 1, 32); + string h2 = string(printHash32(hashString(htSHA256, "rewrite:" + drvPath + ":" + *i)), 0, 32); + Path p = settings.nixStore + "/" + h2 + string(*i, settings.nixStore.size() + 33); + assert(i->size() == p.size()); + rewritesToTmp[h1] = h2; + rewritesFromTmp[h2] = h1; + redirectedOutputs.insert(p); + } } @@ -1925,7 +1981,7 @@ void DerivationGoal::initChild() /* Fill in the environment. */ Strings envStrs; foreach (Environment::const_iterator, i, env) - envStrs.push_back(i->first + "=" + i->second); + envStrs.push_back(rewriteHashes(i->first + "=" + i->second, rewritesToTmp)); const char * * envArr = strings2CharPtrs(envStrs); Path program = drv.builder.c_str(); @@ -1971,7 +2027,7 @@ void DerivationGoal::initChild() string builderBasename = baseNameOf(drv.builder); args.push_back(builderBasename.c_str()); foreach (Strings::iterator, i, drv.args) - args.push_back(i->c_str()); + args.push_back(rewriteHashes(*i, rewritesToTmp).c_str()); args.push_back(0); restoreSIGPIPE(); |