forked from lix-project/lix
Robert Hensing
ad24921de8
It does not operate on a derivation and does not return a derivation path. Instead it works at the language level, where a distinct term "package" is more appropriate to distinguish the parent object of `meta.position`; an attribute which doesn't even make it into the derivation.
135 lines
3.7 KiB
C++
135 lines
3.7 KiB
C++
#include "attr-path.hh"
|
|
#include "eval-inline.hh"
|
|
#include "util.hh"
|
|
|
|
|
|
namespace nix {
|
|
|
|
|
|
static Strings parseAttrPath(std::string_view s)
|
|
{
|
|
Strings res;
|
|
string cur;
|
|
auto i = s.begin();
|
|
while (i != s.end()) {
|
|
if (*i == '.') {
|
|
res.push_back(cur);
|
|
cur.clear();
|
|
} else if (*i == '"') {
|
|
++i;
|
|
while (1) {
|
|
if (i == s.end())
|
|
throw ParseError("missing closing quote in selection path '%1%'", s);
|
|
if (*i == '"') break;
|
|
cur.push_back(*i++);
|
|
}
|
|
} else
|
|
cur.push_back(*i);
|
|
++i;
|
|
}
|
|
if (!cur.empty()) res.push_back(cur);
|
|
return res;
|
|
}
|
|
|
|
|
|
std::vector<Symbol> parseAttrPath(EvalState & state, std::string_view s)
|
|
{
|
|
std::vector<Symbol> res;
|
|
for (auto & a : parseAttrPath(s))
|
|
res.push_back(state.symbols.create(a));
|
|
return res;
|
|
}
|
|
|
|
|
|
std::pair<Value *, Pos> findAlongAttrPath(EvalState & state, const string & attrPath,
|
|
Bindings & autoArgs, Value & vIn)
|
|
{
|
|
Strings tokens = parseAttrPath(attrPath);
|
|
|
|
Value * v = &vIn;
|
|
Pos pos = noPos;
|
|
|
|
for (auto & attr : tokens) {
|
|
|
|
/* Is i an index (integer) or a normal attribute name? */
|
|
auto attrIndex = string2Int<unsigned int>(attr);
|
|
|
|
/* Evaluate the expression. */
|
|
Value * vNew = state.allocValue();
|
|
state.autoCallFunction(autoArgs, *v, *vNew);
|
|
v = vNew;
|
|
state.forceValue(*v);
|
|
|
|
/* It should evaluate to either a set or an expression,
|
|
according to what is specified in the attrPath. */
|
|
|
|
if (!attrIndex) {
|
|
|
|
if (v->type() != nAttrs)
|
|
throw TypeError(
|
|
"the expression selected by the selection path '%1%' should be a set but is %2%",
|
|
attrPath,
|
|
showType(*v));
|
|
if (attr.empty())
|
|
throw Error("empty attribute name in selection path '%1%'", attrPath);
|
|
|
|
Bindings::iterator a = v->attrs->find(state.symbols.create(attr));
|
|
if (a == v->attrs->end())
|
|
throw AttrPathNotFound("attribute '%1%' in selection path '%2%' not found", attr, attrPath);
|
|
v = &*a->value;
|
|
pos = *a->pos;
|
|
}
|
|
|
|
else {
|
|
|
|
if (!v->isList())
|
|
throw TypeError(
|
|
"the expression selected by the selection path '%1%' should be a list but is %2%",
|
|
attrPath,
|
|
showType(*v));
|
|
if (*attrIndex >= v->listSize())
|
|
throw AttrPathNotFound("list index %1% in selection path '%2%' is out of range", *attrIndex, attrPath);
|
|
|
|
v = v->listElems()[*attrIndex];
|
|
pos = noPos;
|
|
}
|
|
|
|
}
|
|
|
|
return {v, pos};
|
|
}
|
|
|
|
|
|
Pos findPackageFilename(EvalState & state, Value & v, std::string what)
|
|
{
|
|
Value * v2;
|
|
try {
|
|
auto dummyArgs = state.allocBindings(0);
|
|
v2 = findAlongAttrPath(state, "meta.position", *dummyArgs, v).first;
|
|
} catch (Error &) {
|
|
throw NoPositionInfo("package '%s' has no source location information", what);
|
|
}
|
|
|
|
// FIXME: is it possible to extract the Pos object instead of doing this
|
|
// toString + parsing?
|
|
auto pos = state.forceString(*v2);
|
|
|
|
auto colon = pos.rfind(':');
|
|
if (colon == std::string::npos)
|
|
throw ParseError("cannot parse meta.position attribute '%s'", pos);
|
|
|
|
std::string filename(pos, 0, colon);
|
|
unsigned int lineno;
|
|
try {
|
|
lineno = std::stoi(std::string(pos, colon + 1));
|
|
} catch (std::invalid_argument & e) {
|
|
throw ParseError("cannot parse line number '%s'", pos);
|
|
}
|
|
|
|
Symbol file = state.symbols.create(filename);
|
|
|
|
return { foFile, file, lineno, 0 };
|
|
}
|
|
|
|
|
|
}
|