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|
%glr-parser
%locations
%define parse.error verbose
%define api.pure true
%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 {
#define YY_NO_INPUT 1 // disable unused yyinput features
#include "libexpr/parser.hh"
// Allow GC tracing of YY-allocated structures
#define YYMALLOC GC_MALLOC_UNCOLLECTABLE
#define YYFREE GC_FREE
#define YYREALLOC GC_REALLOC
struct YYSTYPE : public gc {
union {
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;
nix::AttrNameVector * attrNames;
nix::VectorExprs * string_parts;
};
};
}
%{
#include "generated/parser-tab.hh"
#include "generated/lexer-tab.hh"
YY_DECL;
using namespace nix;
namespace nix {
static inline Pos makeCurPos(const YYLTYPE& loc, ParseData* data) {
return Pos(data->path, loc.first_line, loc.first_column);
}
void yyerror(YYLTYPE* loc, yyscan_t scanner, ParseData* data,
const char* error) {
data->error = (format("%1%, at %2%") % error % makeCurPos(*loc, data)).str();
}
}
%}
%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
%right IMPL
%left OR
%left AND
%nonassoc EQ NEQ
%nonassoc '<' '>' 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 nix::VectorExprs({$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() + std::string{$1 + 1}); }
| SPATH {
std::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 nix::VectorExprs; $$->push_back($2); }
| STR DOLLAR_CURLY expr '}' {
$$ = new nix::VectorExprs;
$$->push_back($1);
$$->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); }
| { $$ = new nix::VectorExprs; }
;
binds
: binds attrpath '=' expr ';' { $$ = $1; addAttr($$, *$2, $4, makeCurPos(@2, data)); }
| binds INHERIT attrs ';'
{ $$ = $1;
for (auto & i : *$3) {
auto sym = std::get<Symbol>(i);
if ($$->attrs.find(sym) != $$->attrs.end()) {
dupAttr(sym, makeCurPos(@3, data), $$->attrs[sym].pos);
}
Pos pos = makeCurPos(@3, data);
$$->attrs[sym] = ExprAttrs::AttrDef(new ExprVar(CUR_POS, sym), pos, true);
}
}
| binds INHERIT '(' expr ')' attrs ';'
{ $$ = $1;
/* !!! Should ensure sharing of the expression in $4. */
for (auto & i : *$6) {
auto sym = std::get<Symbol>(i);
if ($$->attrs.find(sym) != $$->attrs.end()) {
dupAttr(sym, makeCurPos(@6, data), $$->attrs[sym].pos);
}
$$->attrs[sym] = ExprAttrs::AttrDef(new ExprSelect(CUR_POS, $4, sym), makeCurPos(@6, data));
}
}
| { $$ = 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 { $$ = new nix::AttrNameVector; $$->push_back(AttrName(data->symbols.Create($1))); }
| string_attr
{ $$ = new nix::AttrNameVector;
ExprString *str = dynamic_cast<ExprString *>($1);
if (str) {
$$->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 "libexpr/eval.hh"
#include "libstore/store-api.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) {
throw ParseError(data.error);
}
data.result->bindVars(staticEnv);
return data.result;
}
} // namespace nix
|