nix-super/src/libexpr/get-drvs.hh
Eelco Dolstra c6120352b3 * In nix-instantiate, allow us to specify a "path" to the
derivation(s) we're interested, e.g.,

    $ nix-instantiate ./all-packages.nix --attr xlibs.libX11

  List elements can also be selected:

    $ nix-instantiate ./build-for-release.nix --attr 0.subversion

  This allows a non-ambiguous specification of a derivation.  Of
  course, this should also be added to nix-env and nix-build.
2006-02-10 17:25:59 +00:00

65 lines
1.3 KiB
C++

#ifndef __GET_DRVS_H
#define __GET_DRVS_H
#include <string>
#include <map>
#include "eval.hh"
struct DrvInfo
{
private:
string drvPath;
string outPath;
public:
string name;
string system;
ATermMap attrs;
string queryDrvPath(EvalState & state) const
{
if (drvPath == "") {
Expr a = attrs.get("drvPath");
(string &) drvPath = a ? evalPath(state, a) : "";
}
return drvPath;
}
string queryOutPath(EvalState & state) const
{
if (outPath == "") {
Expr a = attrs.get("outPath");
if (!a) throw Error("output path missing");
(string &) outPath = evalPath(state, a);
}
return outPath;
}
void setDrvPath(const string & s)
{
drvPath = s;
}
void setOutPath(const string & s)
{
outPath = s;
}
};
typedef list<DrvInfo> DrvInfos;
/* Evaluate expression `e'. If it evaluates to a derivation, store
information about the derivation in `drv' and return true.
Otherwise, return false. */
bool getDerivation(EvalState & state, Expr e, DrvInfo & drv);
void getDerivations(EvalState & state, Expr e, DrvInfos & drvs,
const string & attrPath = "");
#endif /* !__GET_DRVS_H */