wroclaw-git-backups/nix
1
0
Fork 0
mirror of https://github.com/NixOS/nix synced 2025-06-26 03:21:16 +02:00
Code Activity

Force all Pos* to be non-null

Browse source 
This fixes a class of crashes and introduces ptr<T> to make the
code robust against this failure mode going forward.

Thanks regnat for the idea of a ref<T> without overhead!

Closes #4895
Closes #4893
Closes #5127
Closes #5113
This commit is contained in:
Robert Hensing 2021-08-29 18:09:13 +02:00
parent af94b54db3
commit f10465774f
7 changed files with 65 additions and 22 deletions
Download patch file Download diff file Expand all files Collapse all files

24
src/libexpr/eval.cc
View file

@ -770,7 +770,7 @@ inline Value * EvalState::lookupVar(Env * env, const ExprVar & var, bool noEval)
}
Bindings::iterator j = env->values[0]->attrs->find(var.name);
if (j != env->values[0]->attrs->end()) {
if (countCalls && j->pos) attrSelects[*j->pos]++;
if (countCalls) attrSelects[*j->pos]++;
return j->value;
}
if (!env->prevWith)
@ -825,9 +825,9 @@ void EvalState::mkThunk_(Value & v, Expr * expr)
}
void EvalState::mkPos(Value & v, Pos * pos)
void EvalState::mkPos(Value & v, ptr<Pos> pos)
{
if (pos && pos->file.set()) {
if (pos->file.set()) {
mkAttrs(v, 3);
mkString(*allocAttr(v, sFile), pos->file);
mkInt(*allocAttr(v, sLine), pos->line);
@ -1027,7 +1027,7 @@ void ExprAttrs::eval(EvalState & state, Env & env, Value & v)
} else
vAttr = i.second.e->maybeThunk(state, i.second.inherited ? env : env2);
env2.values[displ++] = vAttr;
v.attrs->push_back(Attr(i.first, vAttr, &i.second.pos));
v.attrs->push_back(Attr(i.first, vAttr, ptr(&i.second.pos)));
}
/* If the rec contains an attribute called `__overrides', then
@ -1059,7 +1059,7 @@ void ExprAttrs::eval(EvalState & state, Env & env, Value & v)
else
for (auto & i : attrs)
v.attrs->push_back(Attr(i.first, i.second.e->maybeThunk(state, env), &i.second.pos));
v.attrs->push_back(Attr(i.first, i.second.e->maybeThunk(state, env), ptr(&i.second.pos)));
/* Dynamic attrs apply *after* rec and __overrides. */
for (auto & i : dynamicAttrs) {
@ -1076,11 +1076,11 @@ void ExprAttrs::eval(EvalState & state, Env & env, Value & v)
i.valueExpr->setName(nameSym);
/* Keep sorted order so find can catch duplicates */
v.attrs->push_back(Attr(nameSym, i.valueExpr->maybeThunk(state, *dynamicEnv), &i.pos));
v.attrs->push_back(Attr(nameSym, i.valueExpr->maybeThunk(state, *dynamicEnv), ptr(&i.pos)));
v.attrs->sort(); // FIXME: inefficient
}
v.attrs->pos = &pos;
v.attrs->pos = ptr(&pos);
}
@ -1138,7 +1138,7 @@ static string showAttrPath(EvalState & state, Env & env, const AttrPath & attrPa
void ExprSelect::eval(EvalState & state, Env & env, Value & v)
{
Value vTmp;
Pos * pos2 = 0;
ptr<Pos> pos2(&noPos);
Value * vAttrs = &vTmp;
e->eval(state, env, vTmp);
@ -1164,13 +1164,13 @@ void ExprSelect::eval(EvalState & state, Env & env, Value & v)
}
vAttrs = j->value;
pos2 = j->pos;
if (state.countCalls && pos2) state.attrSelects[*pos2]++;
if (state.countCalls) state.attrSelects[*pos2]++;
}
state.forceValue(*vAttrs, ( pos2 != NULL ? *pos2 : this->pos ) );
state.forceValue(*vAttrs, (*pos2 != noPos ? *pos2 : this->pos ) );
} catch (Error & e) {
if (pos2 && pos2->file != state.sDerivationNix)
if (*pos2 != noPos && pos2->file != state.sDerivationNix)
addErrorTrace(e, *pos2, "while evaluating the attribute '%1%'",
showAttrPath(state, env, attrPath));
throw;
@ -1616,7 +1616,7 @@ void ExprConcatStrings::eval(EvalState & state, Env & env, Value & v)
void ExprPos::eval(EvalState & state, Env & env, Value & v)
{
state.mkPos(v, &pos);
state.mkPos(v, ptr(&pos));
}