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evaluate inherit (from) exprs only once per directive

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desugaring inherit-from to syntactic duplication of the source expr also
duplicates side effects of the source expr (such as trace calls) and
expensive computations (such as derivationStrict).
This commit is contained in:
pennae 2024-01-27 16:33:34 +01:00
parent ecf8b12d60
commit cefd0302b5
9 changed files with 109 additions and 15 deletions
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11
src/libexpr/parser-state.hh
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@ -118,13 +118,24 @@ inline void ParserState::addAttr(ExprAttrs * attrs, AttrPath && attrPath, Expr *
auto ae = dynamic_cast<ExprAttrs *>(e);
auto jAttrs = dynamic_cast<ExprAttrs *>(j->second.e);
if (jAttrs && ae) {
if (ae->inheritFromExprs && !jAttrs->inheritFromExprs)
jAttrs->inheritFromExprs = std::make_unique<std::vector<Expr *>>();
for (auto & ad : ae->attrs) {
auto j2 = jAttrs->attrs.find(ad.first);
if (j2 != jAttrs->attrs.end()) // Attr already defined in iAttrs, error.
dupAttr(ad.first, j2->second.pos, ad.second.pos);
jAttrs->attrs.emplace(ad.first, ad.second);
if (ad.second.kind == ExprAttrs::AttrDef::Kind::InheritedFrom) {
auto & sel = dynamic_cast<ExprSelect &>(*ad.second.e);
auto & from = dynamic_cast<ExprInheritFrom &>(*sel.e);
from.displ += jAttrs->inheritFromExprs->size();
}
}
jAttrs->dynamicAttrs.insert(jAttrs->dynamicAttrs.end(), ae->dynamicAttrs.begin(), ae->dynamicAttrs.end());
if (ae->inheritFromExprs) {
jAttrs->inheritFromExprs->insert(jAttrs->inheritFromExprs->end(),
ae->inheritFromExprs->begin(), ae->inheritFromExprs->end());
}
} else {
dupAttr(attrPath, pos, j->second.pos);
}