#include <map> #include <iostream> #include "globals.hh" #include "normalise.hh" #include "shared.hh" typedef ATerm Expr; typedef map<ATerm, ATerm> NormalForms; typedef map<Path, PathSet> PkgPaths; typedef map<Path, Hash> PkgHashes; struct EvalState { Paths searchDirs; NormalForms normalForms; PkgPaths pkgPaths; PkgHashes pkgHashes; /* normalised package hashes */ Expr blackHole; EvalState() { blackHole = ATmake("BlackHole()"); if (!blackHole) throw Error("cannot build black hole"); } }; static Expr evalFile(EvalState & state, const Path & path); static Expr evalExpr(EvalState & state, Expr e); static Path searchPath(const Paths & searchDirs, const Path & relPath) { if (string(relPath, 0, 1) == "/") return relPath; for (Paths::const_iterator i = searchDirs.begin(); i != searchDirs.end(); i++) { Path path = *i + "/" + relPath; if (pathExists(path)) return path; } throw Error( format("path `%1%' not found in any of the search directories") % relPath); } static Expr substExpr(string x, Expr rep, Expr e) { char * s; Expr e2; if (ATmatch(e, "Var(<str>)", &s)) if (x == s) return rep; else return e; ATermList formals; if (ATmatch(e, "Function([<list>], <term>)", &formals, &e2)) { while (!ATisEmpty(formals)) { if (!ATmatch(ATgetFirst(formals), "<str>", &s)) throw badTerm("not a list of formals", (ATerm) formals); if (x == (string) s) return e; formals = ATgetNext(formals); } } /* Generically substitute in subterms. */ if (ATgetType(e) == AT_APPL) { AFun fun = ATgetAFun(e); int arity = ATgetArity(fun); ATermList args = ATempty; for (int i = arity - 1; i >= 0; i--) args = ATinsert(args, substExpr(x, rep, ATgetArgument(e, i))); return (ATerm) ATmakeApplList(fun, args); } if (ATgetType(e) == AT_LIST) { ATermList in = (ATermList) e; ATermList out = ATempty; while (!ATisEmpty(in)) { out = ATinsert(out, substExpr(x, rep, ATgetFirst(in))); in = ATgetNext(in); } return (ATerm) ATreverse(out); } throw badTerm("do not know how to substitute", e); } static Expr substExprMany(ATermList formals, ATermList args, Expr body) { char * s; Expr e; /* !!! check args against formals */ while (!ATisEmpty(args)) { ATerm tup = ATgetFirst(args); if (!ATmatch(tup, "(<str>, <term>)", &s, &e)) throw badTerm("expected an argument tuple", tup); body = substExpr(s, e, body); args = ATgetNext(args); } return body; } static PathSet nixExprRootsCached(EvalState & state, const Path & nePath) { PkgPaths::iterator i = state.pkgPaths.find(nePath); if (i != state.pkgPaths.end()) return i->second; else { PathSet paths = nixExprRoots(nePath); state.pkgPaths[nePath] = paths; return paths; } } static Hash hashPackage(EvalState & state, NixExpr ne) { if (ne.type == NixExpr::neDerivation) { PathSet inputs2; for (PathSet::iterator i = ne.derivation.inputs.begin(); i != ne.derivation.inputs.end(); i++) { PkgHashes::iterator j = state.pkgHashes.find(*i); if (j == state.pkgHashes.end()) throw Error(format("don't know expression `%1%'") % (string) *i); inputs2.insert(j->second); } ne.derivation.inputs = inputs2; } return hashTerm(unparseNixExpr(ne)); } static string processBinding(EvalState & state, Expr e, NixExpr & ne) { char * s1; if (ATmatch(e, "NixExpr(<str>)", &s1)) { Path nePath(s1); PathSet paths = nixExprRootsCached(state, nePath); if (paths.size() != 1) abort(); Path path = *(paths.begin()); ne.derivation.inputs.insert(nePath); return path; } if (ATmatch(e, "<str>", &s1)) return s1; if (ATmatch(e, "True")) return "1"; if (ATmatch(e, "False")) return ""; ATermList l; if (ATmatch(e, "[<list>]", &l)) { string s; bool first = true; while (!ATisEmpty(l)) { if (!first) s = s + " "; else first = false; s += processBinding(state, evalExpr(state, ATgetFirst(l)), ne); l = ATgetNext(l); } return s; } throw badTerm("invalid package binding", e); } static Expr evalExpr2(EvalState & state, Expr e) { char * s1; Expr e1, e2, e3, e4; ATermList bnds; /* Normal forms. */ if (ATmatch(e, "<str>", &s1) || ATmatch(e, "[<list>]", &e1) || ATmatch(e, "True") || ATmatch(e, "False") || ATmatch(e, "Function([<list>], <term>)", &e1, &e2) || ATmatch(e, "NixExpr(<str>)", &s1)) return e; try { Hash pkgHash = hashPackage(state, parseNixExpr(e)); Path pkgPath = writeTerm(e, ""); state.pkgHashes[pkgPath] = pkgHash; return ATmake("NixExpr(<str>)", pkgPath.c_str()); } catch (...) { /* !!! catch parse errors only */ } /* Application. */ if (ATmatch(e, "Call(<term>, [<list>])", &e1, &e2) || ATmatch(e, "App(<term>, [<list>])", &e1, &e2)) { e1 = evalExpr(state, e1); if (!ATmatch(e1, "Function([<list>], <term>)", &e3, &e4)) throw badTerm("expecting a function", e1); return evalExpr(state, substExprMany((ATermList) e3, (ATermList) e2, e4)); } /* Conditional. */ if (ATmatch(e, "If(<term>, <term>, <term>)", &e1, &e2, &e3)) { e1 = evalExpr(state, e1); Expr x; if (ATmatch(e1, "True")) x = e2; else if (ATmatch(e1, "False")) x = e3; else throw badTerm("expecting a boolean", e1); return evalExpr(state, x); } /* Ad-hoc function for string matching. */ if (ATmatch(e, "HasSubstr(<term>, <term>)", &e1, &e2)) { e1 = evalExpr(state, e1); e2 = evalExpr(state, e2); char * s1, * s2; if (!ATmatch(e1, "<str>", &s1)) throw badTerm("expecting a string", e1); if (!ATmatch(e2, "<str>", &s2)) throw badTerm("expecting a string", e2); return string(s1).find(string(s2)) != string::npos ? ATmake("True") : ATmake("False"); } /* Platform constant. */ if (ATmatch(e, "Platform")) { return ATmake("<str>", SYSTEM); } /* Fix inclusion. */ if (ATmatch(e, "IncludeFix(<str>)", &s1)) { Path fileName(s1); return evalFile(state, s1); } /* Relative files. */ if (ATmatch(e, "Relative(<str>)", &s1)) { Path srcPath = searchPath(state.searchDirs, s1); Path dstPath = addToStore(srcPath); ClosureElem elem; NixExpr ne; ne.type = NixExpr::neClosure; ne.closure.roots.insert(dstPath); ne.closure.elems[dstPath] = elem; Hash pkgHash = hashPackage(state, ne); Path pkgPath = writeTerm(unparseNixExpr(ne), ""); state.pkgHashes[pkgPath] = pkgHash; msg(lvlChatty, format("copied `%1%' -> closure `%2%'") % srcPath % pkgPath); return ATmake("NixExpr(<str>)", pkgPath.c_str()); } /* Packages are transformed into Nix derivation expressions. */ if (ATmatch(e, "Package([<list>])", &bnds)) { /* Evaluate the bindings and put them in a map. */ map<string, ATerm> bndMap; bndMap["platform"] = ATmake("<str>", SYSTEM); while (!ATisEmpty(bnds)) { ATerm bnd = ATgetFirst(bnds); if (!ATmatch(bnd, "(<str>, <term>)", &s1, &e1)) throw badTerm("binding expected", bnd); bndMap[s1] = evalExpr(state, e1); bnds = ATgetNext(bnds); } /* Gather information for building the derivation expression. */ NixExpr ne; ne.type = NixExpr::neDerivation; ne.derivation.platform = SYSTEM; string name; Path outPath; Hash outHash; bool outHashGiven = false; bnds = ATempty; for (map<string, ATerm>::iterator it = bndMap.begin(); it != bndMap.end(); it++) { string key = it->first; ATerm value = it->second; if (key == "args") { ATermList args; if (!ATmatch(value, "[<list>]", &args)) throw badTerm("list expected", value); while (!ATisEmpty(args)) { Expr arg = evalExpr(state, ATgetFirst(args)); ne.derivation.args.push_back(processBinding(state, arg, ne)); args = ATgetNext(args); } } else { string s = processBinding(state, value, ne); ne.derivation.env[key] = s; if (key == "build") ne.derivation.builder = s; if (key == "name") name = s; if (key == "outPath") outPath = s; if (key == "id") { outHash = parseHash(s); outHashGiven = true; } } bnds = ATinsert(bnds, ATmake("(<str>, <term>)", key.c_str(), value)); } if (ne.derivation.builder == "") throw badTerm("no builder specified", e); if (name == "") throw badTerm("no package name specified", e); /* Determine the output path. */ if (!outHashGiven) outHash = hashPackage(state, ne); if (outPath == "") /* Hash the Nix expression with no outputs to produce a unique but deterministic path name for this package. */ outPath = canonPath(nixStore + "/" + ((string) outHash).c_str() + "-" + name); ne.derivation.env["out"] = outPath; ne.derivation.outputs.insert(outPath); /* Write the resulting term into the Nix store directory. */ Hash pkgHash = outHashGiven ? hashString((string) outHash + outPath) : hashPackage(state, ne); Path pkgPath = writeTerm(unparseNixExpr(ne), "-d-" + name); state.pkgHashes[pkgPath] = pkgHash; msg(lvlChatty, format("instantiated `%1%' -> `%2%'") % name % pkgPath); return ATmake("NixExpr(<str>)", pkgPath.c_str()); } /* BaseName primitive function. */ if (ATmatch(e, "BaseName(<term>)", &e1)) { e1 = evalExpr(state, e1); if (!ATmatch(e1, "<str>", &s1)) throw badTerm("string expected", e1); return ATmake("<str>", baseNameOf(s1).c_str()); } /* Barf. */ throw badTerm("invalid expression", e); } static Expr evalExpr(EvalState & state, Expr e) { Nest nest(lvlVomit, format("evaluating expression: %1%") % printTerm(e)); /* Consult the memo table to quickly get the normal form of previously evaluated expressions. */ NormalForms::iterator i = state.normalForms.find(e); if (i != state.normalForms.end()) { if (i->second == state.blackHole) throw badTerm("infinite recursion", e); return i->second; } /* Otherwise, evaluate and memoize. */ state.normalForms[e] = state.blackHole; Expr nf = evalExpr2(state, e); state.normalForms[e] = nf; return nf; } static Expr evalFile(EvalState & state, const Path & relPath) { Path path = searchPath(state.searchDirs, relPath); Nest nest(lvlTalkative, format("evaluating file `%1%'") % path); Expr e = ATreadFromNamedFile(path.c_str()); if (!e) throw Error(format("unable to read a term from `%1%'") % path); return evalExpr(state, e); } static Expr evalStdin(EvalState & state) { Nest nest(lvlTalkative, format("evaluating standard input")); Expr e = ATreadFromFile(stdin); if (!e) throw Error(format("unable to read a term from stdin")); return evalExpr(state, e); } static void printNixExpr(EvalState & state, Expr e) { ATermList es; char * s; if (ATmatch(e, "NixExpr(<str>)", &s)) { cout << format("%1%\n") % s; } else if (ATmatch(e, "[<list>]", &es)) { while (!ATisEmpty(es)) { printNixExpr(state, evalExpr(state, ATgetFirst(es))); es = ATgetNext(es); } } else throw badTerm("top level does not evaluate to a (list of) Nix expression(s)", e); } void run(Strings args) { EvalState state; Strings files; bool readStdin = false; state.searchDirs.push_back("."); state.searchDirs.push_back(nixDataDir + "/fix"); for (Strings::iterator it = args.begin(); it != args.end(); ) { string arg = *it++; if (arg == "--includedir" || arg == "-I") { if (it == args.end()) throw UsageError(format("argument required in `%1%'") % arg); state.searchDirs.push_back(*it++); } else if (arg == "--verbose" || arg == "-v") verbosity = (Verbosity) ((int) verbosity + 1); else if (arg == "-") readStdin = true; else if (arg[0] == '-') throw UsageError(format("unknown flag `%1%`") % arg); else files.push_back(arg); } openDB(); if (readStdin) { Expr e = evalStdin(state); printNixExpr(state, e); } for (Strings::iterator it = files.begin(); it != files.end(); it++) { Expr e = evalFile(state, *it); printNixExpr(state, e); } } string programId = "fix";