%glr-parser %pure-parser %locations %error-verbose %defines /* %no-lines */ %parse-param { void * scanner } %parse-param { nix::ParseData * data } %lex-param { void * scanner } %lex-param { nix::ParseData * data } %expect 1 %expect-rr 1 %code requires { #ifndef BISON_HEADER #define BISON_HEADER #include "util.hh" #include "nixexpr.hh" #include "eval.hh" namespace nix { struct ParseData { EvalState & state; SymbolTable & symbols; Expr * result; Path basePath; Symbol path; string error; bool atEnd; Symbol sLetBody; ParseData(EvalState & state) : state(state) , symbols(state.symbols) , atEnd(false) , sLetBody(symbols.create("<let-body>")) { }; }; } #define YY_DECL int yylex \ (YYSTYPE * yylval_param, YYLTYPE * yylloc_param, yyscan_t yyscanner, nix::ParseData * data) #endif } %{ #include "parser-tab.hh" #include "lexer-tab.hh" YY_DECL; using namespace nix; namespace nix { static void dupAttr(const AttrPath & attrPath, const Pos & pos, const Pos & prevPos) { throw ParseError(format("attribute ‘%1%’ at %2% already defined at %3%") % showAttrPath(attrPath) % pos % prevPos); } static void dupAttr(Symbol attr, const Pos & pos, const Pos & prevPos) { throw ParseError(format("attribute ‘%1%’ at %2% already defined at %3%") % attr % pos % prevPos); } static void addAttr(ExprAttrs * attrs, AttrPath & attrPath, Expr * e, const Pos & pos) { AttrPath::iterator i; // All attrpaths have at least one attr assert(!attrPath.empty()); for (i = attrPath.begin(); i + 1 < attrPath.end(); i++) { if (i->symbol.set()) { ExprAttrs::AttrDefs::iterator j = attrs->attrs.find(i->symbol); if (j != attrs->attrs.end()) { if (!j->second.inherited) { ExprAttrs * attrs2 = dynamic_cast<ExprAttrs *>(j->second.e); if (!attrs2) dupAttr(attrPath, pos, j->second.pos); attrs = attrs2; } else dupAttr(attrPath, pos, j->second.pos); } else { ExprAttrs * nested = new ExprAttrs; attrs->attrs[i->symbol] = ExprAttrs::AttrDef(nested, pos); attrs = nested; } } else { ExprAttrs *nested = new ExprAttrs; attrs->dynamicAttrs.push_back(ExprAttrs::DynamicAttrDef(i->expr, nested, pos)); attrs = nested; } } if (i->symbol.set()) { ExprAttrs::AttrDefs::iterator j = attrs->attrs.find(i->symbol); if (j != attrs->attrs.end()) { dupAttr(attrPath, pos, j->second.pos); } else { attrs->attrs[i->symbol] = ExprAttrs::AttrDef(e, pos); e->setName(i->symbol); } } else { attrs->dynamicAttrs.push_back(ExprAttrs::DynamicAttrDef(i->expr, e, pos)); } } static void addFormal(const Pos & pos, Formals * formals, const Formal & formal) { if (formals->argNames.find(formal.name) != formals->argNames.end()) throw ParseError(format("duplicate formal function argument ‘%1%’ at %2%") % formal.name % pos); formals->formals.push_front(formal); formals->argNames.insert(formal.name); } static Expr * stripIndentation(const Pos & pos, SymbolTable & symbols, vector<Expr *> & es) { if (es.empty()) return new ExprString(symbols.create("")); /* Figure out the minimum indentation. Note that by design whitespace-only final lines are not taken into account. (So the " " in "\n ''" is ignored, but the " " in "\n foo''" is.) */ bool atStartOfLine = true; /* = seen only whitespace in the current line */ unsigned int minIndent = 1000000; unsigned int curIndent = 0; for (auto & i : es) { ExprIndStr * e = dynamic_cast<ExprIndStr *>(i); if (!e) { /* Anti-quotations end the current start-of-line whitespace. */ if (atStartOfLine) { atStartOfLine = false; if (curIndent < minIndent) minIndent = curIndent; } continue; } for (unsigned int j = 0; j < e->s.size(); ++j) { if (atStartOfLine) { if (e->s[j] == ' ') curIndent++; else if (e->s[j] == '\n') { /* Empty line, doesn't influence minimum indentation. */ curIndent = 0; } else { atStartOfLine = false; if (curIndent < minIndent) minIndent = curIndent; } } else if (e->s[j] == '\n') { atStartOfLine = true; curIndent = 0; } } } /* Strip spaces from each line. */ vector<Expr *> * es2 = new vector<Expr *>; atStartOfLine = true; unsigned int curDropped = 0; unsigned int n = es.size(); for (vector<Expr *>::iterator i = es.begin(); i != es.end(); ++i, --n) { ExprIndStr * e = dynamic_cast<ExprIndStr *>(*i); if (!e) { atStartOfLine = false; curDropped = 0; es2->push_back(*i); continue; } string s2; for (unsigned int j = 0; j < e->s.size(); ++j) { if (atStartOfLine) { if (e->s[j] == ' ') { if (curDropped++ >= minIndent) s2 += e->s[j]; } else if (e->s[j] == '\n') { curDropped = 0; s2 += e->s[j]; } else { atStartOfLine = false; curDropped = 0; s2 += e->s[j]; } } else { s2 += e->s[j]; if (e->s[j] == '\n') atStartOfLine = true; } } /* Remove the last line if it is empty and consists only of spaces. */ if (n == 1) { string::size_type p = s2.find_last_of('\n'); if (p != string::npos && s2.find_first_not_of(' ', p + 1) == string::npos) s2 = string(s2, 0, p + 1); } es2->push_back(new ExprString(symbols.create(s2))); } /* If this is a single string, then don't do a concatenation. */ return es2->size() == 1 && dynamic_cast<ExprString *>((*es2)[0]) ? (*es2)[0] : new ExprConcatStrings(pos, true, es2); } static inline Pos makeCurPos(const YYLTYPE & loc, ParseData * data) { return Pos(data->path, loc.first_line, loc.first_column); } #define CUR_POS makeCurPos(*yylocp, data) } void yyerror(YYLTYPE * loc, yyscan_t scanner, ParseData * data, const char * error) { data->error = (format("%1%, at %2%") % error % makeCurPos(*loc, data)).str(); } %} %union { // !!! We're probably leaking stuff here. nix::Expr * e; nix::ExprList * list; nix::ExprAttrs * attrs; nix::Formals * formals; nix::Formal * formal; nix::NixInt n; nix::NixFloat nf; const char * id; // !!! -> Symbol char * path; char * uri; std::vector<nix::AttrName> * attrNames; std::vector<nix::Expr *> * string_parts; } %type <e> start expr expr_function expr_if expr_op %type <e> expr_app expr_select expr_simple %type <list> expr_list %type <attrs> binds %type <formals> formals %type <formal> formal %type <attrNames> attrs attrpath %type <string_parts> string_parts_interpolated ind_string_parts %type <e> string_parts string_attr %type <id> attr %token <id> ID ATTRPATH %token <e> STR IND_STR %token <n> INT %token <nf> FLOAT %token <path> PATH HPATH SPATH %token <uri> URI %token IF THEN ELSE ASSERT WITH LET IN REC INHERIT EQ NEQ AND OR IMPL OR_KW %token DOLLAR_CURLY /* == ${ */ %token IND_STRING_OPEN IND_STRING_CLOSE %token ELLIPSIS %nonassoc IMPL %left OR %left AND %nonassoc EQ NEQ %left '<' '>' LEQ GEQ %right UPDATE %left NOT %left '+' '-' %left '*' '/' %right CONCAT %nonassoc '?' %nonassoc NEGATE %% start: expr { data->result = $1; }; expr: expr_function; expr_function : ID ':' expr_function { $$ = new ExprLambda(CUR_POS, data->symbols.create($1), false, 0, $3); } | '{' formals '}' ':' expr_function { $$ = new ExprLambda(CUR_POS, data->symbols.create(""), true, $2, $5); } | '{' formals '}' '@' ID ':' expr_function { $$ = new ExprLambda(CUR_POS, data->symbols.create($5), true, $2, $7); } | ID '@' '{' formals '}' ':' expr_function { $$ = new ExprLambda(CUR_POS, data->symbols.create($1), true, $4, $7); } | ASSERT expr ';' expr_function { $$ = new ExprAssert(CUR_POS, $2, $4); } | WITH expr ';' expr_function { $$ = new ExprWith(CUR_POS, $2, $4); } | LET binds IN expr_function { if (!$2->dynamicAttrs.empty()) throw ParseError(format("dynamic attributes not allowed in let at %1%") % CUR_POS); $$ = new ExprLet($2, $4); } | expr_if ; expr_if : IF expr THEN expr ELSE expr { $$ = new ExprIf($2, $4, $6); } | expr_op ; expr_op : '!' expr_op %prec NOT { $$ = new ExprOpNot($2); } | '-' expr_op %prec NEGATE { $$ = new ExprApp(CUR_POS, new ExprApp(new ExprVar(data->symbols.create("__sub")), new ExprInt(0)), $2); } | expr_op EQ expr_op { $$ = new ExprOpEq($1, $3); } | expr_op NEQ expr_op { $$ = new ExprOpNEq($1, $3); } | expr_op '<' expr_op { $$ = new ExprApp(CUR_POS, new ExprApp(new ExprVar(data->symbols.create("__lessThan")), $1), $3); } | expr_op LEQ expr_op { $$ = new ExprOpNot(new ExprApp(CUR_POS, new ExprApp(new ExprVar(data->symbols.create("__lessThan")), $3), $1)); } | expr_op '>' expr_op { $$ = new ExprApp(CUR_POS, new ExprApp(new ExprVar(data->symbols.create("__lessThan")), $3), $1); } | expr_op GEQ expr_op { $$ = new ExprOpNot(new ExprApp(CUR_POS, new ExprApp(new ExprVar(data->symbols.create("__lessThan")), $1), $3)); } | expr_op AND expr_op { $$ = new ExprOpAnd(CUR_POS, $1, $3); } | expr_op OR expr_op { $$ = new ExprOpOr(CUR_POS, $1, $3); } | expr_op IMPL expr_op { $$ = new ExprOpImpl(CUR_POS, $1, $3); } | expr_op UPDATE expr_op { $$ = new ExprOpUpdate(CUR_POS, $1, $3); } | expr_op '?' attrpath { $$ = new ExprOpHasAttr($1, *$3); } | expr_op '+' expr_op { $$ = new ExprConcatStrings(CUR_POS, false, new vector<Expr *>({$1, $3})); } | expr_op '-' expr_op { $$ = new ExprApp(CUR_POS, new ExprApp(new ExprVar(data->symbols.create("__sub")), $1), $3); } | expr_op '*' expr_op { $$ = new ExprApp(CUR_POS, new ExprApp(new ExprVar(data->symbols.create("__mul")), $1), $3); } | expr_op '/' expr_op { $$ = new ExprApp(CUR_POS, new ExprApp(new ExprVar(data->symbols.create("__div")), $1), $3); } | expr_op CONCAT expr_op { $$ = new ExprOpConcatLists(CUR_POS, $1, $3); } | expr_app ; expr_app : expr_app expr_select { $$ = new ExprApp(CUR_POS, $1, $2); } | expr_select { $$ = $1; } ; expr_select : expr_simple '.' attrpath { $$ = new ExprSelect(CUR_POS, $1, *$3, 0); } | expr_simple '.' attrpath OR_KW expr_select { $$ = new ExprSelect(CUR_POS, $1, *$3, $5); } | /* Backwards compatibility: because Nixpkgs has a rarely used function named ‘or’, allow stuff like ‘map or [...]’. */ expr_simple OR_KW { $$ = new ExprApp(CUR_POS, $1, new ExprVar(CUR_POS, data->symbols.create("or"))); } | expr_simple { $$ = $1; } ; expr_simple : ID { if (strcmp($1, "__curPos") == 0) $$ = new ExprPos(CUR_POS); else $$ = new ExprVar(CUR_POS, data->symbols.create($1)); } | INT { $$ = new ExprInt($1); } | FLOAT { $$ = new ExprFloat($1); } | '"' string_parts '"' { $$ = $2; } | IND_STRING_OPEN ind_string_parts IND_STRING_CLOSE { $$ = stripIndentation(CUR_POS, data->symbols, *$2); } | PATH { $$ = new ExprPath(absPath($1, data->basePath)); } | HPATH { $$ = new ExprPath(getHome() + string{$1 + 1}); } | SPATH { string path($1 + 1, strlen($1) - 2); $$ = new ExprApp(CUR_POS, new ExprApp(new ExprVar(data->symbols.create("__findFile")), new ExprVar(data->symbols.create("__nixPath"))), new ExprString(data->symbols.create(path))); } | URI { $$ = new ExprString(data->symbols.create($1)); } | '(' expr ')' { $$ = $2; } /* Let expressions `let {..., body = ...}' are just desugared into `(rec {..., body = ...}).body'. */ | LET '{' binds '}' { $3->recursive = true; $$ = new ExprSelect(noPos, $3, data->symbols.create("body")); } | REC '{' binds '}' { $3->recursive = true; $$ = $3; } | '{' binds '}' { $$ = $2; } | '[' expr_list ']' { $$ = $2; } ; string_parts : STR | string_parts_interpolated { $$ = new ExprConcatStrings(CUR_POS, true, $1); } | { $$ = new ExprString(data->symbols.create("")); } ; string_parts_interpolated : string_parts_interpolated STR { $$ = $1; $1->push_back($2); } | string_parts_interpolated DOLLAR_CURLY expr '}' { $$ = $1; $1->push_back($3); } | DOLLAR_CURLY expr '}' { $$ = new vector<Expr *>; $$->push_back($2); } | STR DOLLAR_CURLY expr '}' { $$ = new vector<Expr *>; $$->push_back($1); $$->push_back($3); } ; ind_string_parts : ind_string_parts IND_STR { $$ = $1; $1->push_back($2); } | ind_string_parts DOLLAR_CURLY expr '}' { $$ = $1; $1->push_back($3); } | { $$ = new vector<Expr *>; } ; binds : binds attrpath '=' expr ';' { $$ = $1; addAttr($$, *$2, $4, makeCurPos(@2, data)); } | binds INHERIT attrs ';' { $$ = $1; for (auto & i : *$3) { if ($$->attrs.find(i.symbol) != $$->attrs.end()) dupAttr(i.symbol, makeCurPos(@3, data), $$->attrs[i.symbol].pos); Pos pos = makeCurPos(@3, data); $$->attrs[i.symbol] = ExprAttrs::AttrDef(new ExprVar(CUR_POS, i.symbol), pos, true); } } | binds INHERIT '(' expr ')' attrs ';' { $$ = $1; /* !!! Should ensure sharing of the expression in $4. */ for (auto & i : *$6) { if ($$->attrs.find(i.symbol) != $$->attrs.end()) dupAttr(i.symbol, makeCurPos(@6, data), $$->attrs[i.symbol].pos); $$->attrs[i.symbol] = ExprAttrs::AttrDef(new ExprSelect(CUR_POS, $4, i.symbol), makeCurPos(@6, data)); } } | { $$ = new ExprAttrs; } ; attrs : attrs attr { $$ = $1; $1->push_back(AttrName(data->symbols.create($2))); } | attrs string_attr { $$ = $1; ExprString * str = dynamic_cast<ExprString *>($2); if (str) { $$->push_back(AttrName(str->s)); delete str; } else throw ParseError(format("dynamic attributes not allowed in inherit at %1%") % makeCurPos(@2, data)); } | { $$ = new AttrPath; } ; attrpath : attrpath '.' attr { $$ = $1; $1->push_back(AttrName(data->symbols.create($3))); } | attrpath '.' string_attr { $$ = $1; ExprString * str = dynamic_cast<ExprString *>($3); if (str) { $$->push_back(AttrName(str->s)); delete str; } else $$->push_back(AttrName($3)); } | attr { $$ = new vector<AttrName>; $$->push_back(AttrName(data->symbols.create($1))); } | string_attr { $$ = new vector<AttrName>; ExprString *str = dynamic_cast<ExprString *>($1); if (str) { $$->push_back(AttrName(str->s)); delete str; } else $$->push_back(AttrName($1)); } ; attr : ID { $$ = $1; } | OR_KW { $$ = "or"; } ; string_attr : '"' string_parts '"' { $$ = $2; } | DOLLAR_CURLY expr '}' { $$ = $2; } ; expr_list : expr_list expr_select { $$ = $1; $1->elems.push_back($2); /* !!! dangerous */ } | { $$ = new ExprList; } ; formals : formal ',' formals { $$ = $3; addFormal(CUR_POS, $$, *$1); } | formal { $$ = new Formals; addFormal(CUR_POS, $$, *$1); $$->ellipsis = false; } | { $$ = new Formals; $$->ellipsis = false; } | ELLIPSIS { $$ = new Formals; $$->ellipsis = true; } ; formal : ID { $$ = new Formal(data->symbols.create($1), 0); } | ID '?' expr { $$ = new Formal(data->symbols.create($1), $3); } ; %% #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <unistd.h> #include "eval.hh" #include "download.hh" #include "store-api.hh" #include "primops/fetchgit.hh" namespace nix { Expr * EvalState::parse(const char * text, const Path & path, const Path & basePath, StaticEnv & staticEnv) { yyscan_t scanner; ParseData data(*this); data.basePath = basePath; data.path = data.symbols.create(path); yylex_init(&scanner); yy_scan_string(text, scanner); int res = yyparse(scanner, &data); yylex_destroy(scanner); if (res) { if (data.atEnd) throw IncompleteParseError(data.error); else throw ParseError(data.error); } data.result->bindVars(staticEnv); return data.result; } Path resolveExprPath(Path path) { assert(path[0] == '/'); /* If `path' is a symlink, follow it. This is so that relative path references work. */ struct stat st; while (true) { if (lstat(path.c_str(), &st)) throw SysError(format("getting status of ‘%1%’") % path); if (!S_ISLNK(st.st_mode)) break; path = absPath(readLink(path), dirOf(path)); } /* If `path' refers to a directory, append `/default.nix'. */ if (S_ISDIR(st.st_mode)) path = canonPath(path + "/default.nix"); return path; } Expr * EvalState::parseExprFromFile(const Path & path) { return parseExprFromFile(path, staticBaseEnv); } Expr * EvalState::parseExprFromFile(const Path & path, StaticEnv & staticEnv) { return parse(readFile(path).c_str(), path, dirOf(path), staticEnv); } Expr * EvalState::parseExprFromString(const string & s, const Path & basePath, StaticEnv & staticEnv) { return parse(s.c_str(), "(string)", basePath, staticEnv); } Expr * EvalState::parseExprFromString(const string & s, const Path & basePath) { return parseExprFromString(s, basePath, staticBaseEnv); } Expr * EvalState::parseStdin() { //Activity act(*logger, lvlTalkative, format("parsing standard input")); return parseExprFromString(drainFD(0), absPath(".")); } void EvalState::addToSearchPath(const string & s) { size_t pos = s.find('='); string prefix; Path path; if (pos == string::npos) { path = s; } else { prefix = string(s, 0, pos); path = string(s, pos + 1); } searchPath.emplace_back(prefix, path); } Path EvalState::findFile(const string & path) { return findFile(searchPath, path); } Path EvalState::findFile(SearchPath & searchPath, const string & path, const Pos & pos) { for (auto & i : searchPath) { std::string suffix; if (i.first.empty()) suffix = "/" + path; else { auto s = i.first.size(); if (path.compare(0, s, i.first) != 0 || (path.size() > s && path[s] != '/')) continue; suffix = path.size() == s ? "" : "/" + string(path, s); } auto r = resolveSearchPathElem(i); if (!r.first) continue; Path res = r.second + suffix; if (pathExists(res)) return canonPath(res); } format f = format( "file ‘%1%’ was not found in the Nix search path (add it using $NIX_PATH or -I)" + string(pos ? ", at %2%" : "")); f.exceptions(boost::io::all_error_bits ^ boost::io::too_many_args_bit); throw ThrownError(f % path % pos); } std::pair<bool, std::string> EvalState::resolveSearchPathElem(const SearchPathElem & elem) { auto i = searchPathResolved.find(elem.second); if (i != searchPathResolved.end()) return i->second; std::pair<bool, std::string> res; if (isUri(elem.second)) { try { if (hasPrefix(elem.second, "git://") || hasSuffix(elem.second, ".git")) // FIXME: support specifying revision/branch res = { true, exportGit(store, elem.second, "master") }; else res = { true, getDownloader()->downloadCached(store, elem.second, true) }; } catch (DownloadError & e) { printError(format("warning: Nix search path entry ‘%1%’ cannot be downloaded, ignoring") % elem.second); res = { false, "" }; } } else { auto path = absPath(elem.second); if (pathExists(path)) res = { true, path }; else { printError(format("warning: Nix search path entry ‘%1%’ does not exist, ignoring") % elem.second); res = { false, "" }; } } debug(format("resolved search path element ‘%s’ to ‘%s’") % elem.second % res.second); searchPathResolved[elem.second] = res; return res; } }