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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"
struct ParseData
{
Expr result;
string basePath;
string location;
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 string2ATerm(absPath(aterm2String(t), data->basePath).c_str());
}
void parseError(ParseData * data, char * error, int line, int column)
{
data->error = (format("%1%, at line %2%, column %3%, of %4%")
% error % line % column % data->location).str();
}
int yyparse(yyscan_t scanner, ParseData * data);
}
static Expr parse(const char * text, const string & location,
const Path & basePath)
{
yyscan_t scanner;
ParseData data;
data.basePath = basePath;
data.location = location;
yylex_init(&scanner);
yy_scan_string(text, scanner);
int res = yyparse(scanner, &data);
yylex_destroy(scanner);
if (res) throw Error(data.error);
return data.result;
}
Expr parseExprFromFile(Path path)
{
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(text, "`" + path + "'", dirOf(path));
}
Expr parseExprFromString(const string & s, const Path & basePath)
{
return parse(s.c_str(), "(string)", basePath);
}
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