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#include <sstream>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include "aterm.hh"
#include "parser.hh"
#include "nixexpr-ast.hh"
struct ParseData
{
Expr result;
Path basePath;
Path path;
string error;
};
extern "C" {
#include "parser-tab.h"
#include "lexer-tab.h"
/* Callbacks for getting from C to C++. Due to a (small) bug in the
GLR code of Bison we cannot currently compile the parser as C++
code. */
void setParseResult(ParseData * data, ATerm t)
{
data->result = t;
}
ATerm absParsedPath(ParseData * data, ATerm t)
{
return toATerm(absPath(aterm2String(t), data->basePath));
}
void parseError(ParseData * data, char * error, int line, int column)
{
data->error = (format("%1%, at `%2%':%3%:%4%")
% error % data->path % line % column).str();
}
ATerm fixAttrs(int recursive, ATermList as)
{
ATermList bs = ATempty, cs = ATempty;
ATermList * is = recursive ? &cs : &bs;
for (ATermIterator i(as); i; ++i) {
ATermList names;
Expr src;
ATerm pos;
if (matchInherit(*i, src, names, pos)) {
bool fromScope = matchScope(src);
for (ATermIterator j(names); j; ++j) {
Expr rhs = fromScope ? makeVar(*j) : makeSelect(src, *j);
*is = ATinsert(*is, makeBind(*j, rhs, pos));
}
} else bs = ATinsert(bs, *i);
}
if (recursive)
return makeRec(bs, cs);
else
return makeAttrs(bs);
}
const char * getPath(ParseData * data)
{
return data->path.c_str();
}
Expr unescapeStr(const char * s)
{
string t;
char c;
while (c = *s++) {
if (c == '\\') {
assert(*s);
c = *s++;
if (c == 'n') t += "\n";
else if (c == 'r') t += "\r";
else if (c == 't') t += "\t";
else t += c;
}
else t += c;
}
return makeStr(toATerm(t));
}
int yyparse(yyscan_t scanner, ParseData * data);
} /* end of C functions */
static void checkAttrs(ATermMap & names, ATermList bnds)
{
for (ATermIterator i(bnds); i; ++i) {
ATerm name;
Expr e;
ATerm pos;
if (!matchBind(*i, name, e, pos)) abort(); /* can't happen */
if (names.get(name))
throw EvalError(format("duplicate attribute `%1%' at %2%")
% aterm2String(name) % showPos(pos));
names.set(name, name);
}
}
static void checkAttrSets(ATerm e)
{
ATermList formals;
ATerm body, pos;
if (matchFunction(e, formals, body, pos)) {
ATermMap names(ATgetLength(formals));
for (ATermIterator i(formals); i; ++i) {
ATerm name;
Expr deflt;
if (!matchNoDefFormal(*i, name) &&
!matchDefFormal(*i, name, deflt))
abort();
if (names.get(name))
throw EvalError(format("duplicate formal function argument `%1%' at %2%")
% aterm2String(name) % showPos(pos));
names.set(name, name);
}
}
ATermList bnds;
if (matchAttrs(e, bnds)) {
ATermMap names(ATgetLength(bnds));
checkAttrs(names, bnds);
}
ATermList rbnds, nrbnds;
if (matchRec(e, rbnds, nrbnds)) {
ATermMap names(ATgetLength(rbnds) + ATgetLength(nrbnds));
checkAttrs(names, rbnds);
checkAttrs(names, nrbnds);
}
if (ATgetType(e) == AT_APPL) {
int arity = ATgetArity(ATgetAFun(e));
for (int i = 0; i < arity; ++i)
checkAttrSets(ATgetArgument(e, i));
}
else if (ATgetType(e) == AT_LIST)
for (ATermIterator i((ATermList) e); i; ++i)
checkAttrSets(*i);
}
static Expr parse(EvalState & state,
const char * text, const Path & path,
const Path & basePath)
{
yyscan_t scanner;
ParseData data;
data.basePath = basePath;
data.path = path;
yylex_init(&scanner);
yy_scan_string(text, scanner);
int res = yyparse(scanner, &data);
yylex_destroy(scanner);
if (res) throw EvalError(data.error);
try {
checkVarDefs(state.primOps, data.result);
} catch (Error & e) {
throw EvalError(format("%1%, in `%2%'") % e.msg() % path);
}
checkAttrSets(data.result);
return data.result;
}
Expr parseExprFromFile(EvalState & state, Path path)
{
SwitchToOriginalUser sw;
assert(path[0] == '/');
#if 0
/* Perhaps this is already an imploded parse tree? */
Expr e = ATreadFromNamedFile(path.c_str());
if (e) return e;
#endif
/* If `path' is a symlink, follow it. This is so that relative
path references work. */
struct stat st;
if (lstat(path.c_str(), &st))
throw SysError(format("getting status of `%1%'") % path);
if (S_ISLNK(st.st_mode)) path = absPath(readLink(path), dirOf(path));
/* If `path' refers to a directory, append `/default.nix'. */
if (stat(path.c_str(), &st))
throw SysError(format("getting status of `%1%'") % path);
if (S_ISDIR(st.st_mode))
path = canonPath(path + "/default.nix");
/* Read the input file. We can't use SGparseFile() because it's
broken, so we read the input ourselves and call
SGparseString(). */
AutoCloseFD fd = open(path.c_str(), O_RDONLY);
if (fd == -1) throw SysError(format("opening `%1%'") % path);
if (fstat(fd, &st) == -1)
throw SysError(format("statting `%1%'") % path);
char text[st.st_size + 1];
readFull(fd, (unsigned char *) text, st.st_size);
text[st.st_size] = 0;
return parse(state, text, path, dirOf(path));
}
Expr parseExprFromString(EvalState & state,
const string & s, const Path & basePath)
{
return parse(state, s.c_str(), "(string)", basePath);
}
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