From 85b7453a7f2160eb1deeae9ecef5ff795a5f5850 Mon Sep 17 00:00:00 2001 From: Ryan Hendrickson Date: Wed, 14 Aug 2024 00:05:06 -0400 Subject: [PATCH] parser-state: fix attribute merging --- src/libexpr/parser-state.hh | 108 +++++++++++------- .../parse-fail-mixed-nested-attrs1.err.exp | 8 +- .../parse-fail-mixed-nested-attrs2.err.exp | 8 +- tests/unit/libexpr/trivial.cc | 42 +++++++ 4 files changed, 114 insertions(+), 52 deletions(-) diff --git a/src/libexpr/parser-state.hh b/src/libexpr/parser-state.hh index 8ad0d9ad7..21a880e8e 100644 --- a/src/libexpr/parser-state.hh +++ b/src/libexpr/parser-state.hh @@ -88,6 +88,7 @@ struct ParserState void dupAttr(const AttrPath & attrPath, const PosIdx pos, const PosIdx prevPos); void dupAttr(Symbol attr, const PosIdx pos, const PosIdx prevPos); void addAttr(ExprAttrs * attrs, AttrPath && attrPath, const ParserLocation & loc, Expr * e, const ParserLocation & exprLoc); + void addAttr(ExprAttrs * attrs, AttrPath & attrPath, const Symbol & symbol, ExprAttrs::AttrDef && def); Formals * validateFormals(Formals * formals, PosIdx pos = noPos, Symbol arg = {}); Expr * stripIndentation(const PosIdx pos, std::vector>> && es); @@ -120,64 +121,29 @@ inline void ParserState::addAttr(ExprAttrs * attrs, AttrPath && attrPath, const // Checking attrPath validity. // =========================== for (i = attrPath.begin(); i + 1 < attrPath.end(); i++) { + ExprAttrs * nested; if (i->symbol) { ExprAttrs::AttrDefs::iterator j = attrs->attrs.find(i->symbol); if (j != attrs->attrs.end()) { - if (j->second.kind != ExprAttrs::AttrDef::Kind::Inherited) { - ExprAttrs * attrs2 = dynamic_cast(j->second.e); - if (!attrs2) dupAttr(attrPath, pos, j->second.pos); - attrs = attrs2; - } else + nested = dynamic_cast(j->second.e); + if (!nested) { + attrPath.erase(i + 1, attrPath.end()); dupAttr(attrPath, pos, j->second.pos); + } } else { - ExprAttrs * nested = new ExprAttrs; + nested = new ExprAttrs; attrs->attrs[i->symbol] = ExprAttrs::AttrDef(nested, pos); - attrs = nested; } } else { - ExprAttrs *nested = new ExprAttrs; + nested = new ExprAttrs; attrs->dynamicAttrs.push_back(ExprAttrs::DynamicAttrDef(i->expr, nested, pos)); - attrs = nested; } + attrs = nested; } // Expr insertion. // ========================== if (i->symbol) { - ExprAttrs::AttrDefs::iterator j = attrs->attrs.find(i->symbol); - if (j != attrs->attrs.end()) { - // This attr path is already defined. However, if both - // e and the expr pointed by the attr path are two attribute sets, - // we want to merge them. - // Otherwise, throw an error. - auto ae = dynamic_cast(e); - auto jAttrs = dynamic_cast(j->second.e); - if (jAttrs && ae) { - if (ae->inheritFromExprs && !jAttrs->inheritFromExprs) - jAttrs->inheritFromExprs = std::make_unique>(); - 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(*ad.second.e); - auto & from = dynamic_cast(*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); - } - } else { - // This attr path is not defined. Let's create it. - attrs->attrs.emplace(i->symbol, ExprAttrs::AttrDef(e, pos)); - e->setName(i->symbol); - } + addAttr(attrs, attrPath, i->symbol, ExprAttrs::AttrDef(e, pos)); } else { attrs->dynamicAttrs.push_back(ExprAttrs::DynamicAttrDef(i->expr, e, pos)); } @@ -189,6 +155,60 @@ inline void ParserState::addAttr(ExprAttrs * attrs, AttrPath && attrPath, const } } +/** + * Precondition: attrPath is used for error messages and should already contain + * symbol as its last element. + */ +inline void ParserState::addAttr(ExprAttrs * attrs, AttrPath & attrPath, const Symbol & symbol, ExprAttrs::AttrDef && def) +{ + ExprAttrs::AttrDefs::iterator j = attrs->attrs.find(symbol); + if (j != attrs->attrs.end()) { + // This attr path is already defined. However, if both + // e and the expr pointed by the attr path are two attribute sets, + // we want to merge them. + // Otherwise, throw an error. + auto ae = dynamic_cast(def.e); + auto jAttrs = dynamic_cast(j->second.e); + + // N.B. In a world in which we are less bound by our past mistakes, we + // would also test that jAttrs and ae are not recursive. The effect of + // not doing so is that any `rec` marker on ae is discarded, and any + // `rec` marker on jAttrs will apply to the attributes in ae. + // See https://github.com/NixOS/nix/issues/9020. + if (jAttrs && ae) { + if (ae->inheritFromExprs && !jAttrs->inheritFromExprs) + jAttrs->inheritFromExprs = std::make_unique>(); + for (auto & ad : ae->attrs) { + if (ad.second.kind == ExprAttrs::AttrDef::Kind::InheritedFrom) { + auto & sel = dynamic_cast(*ad.second.e); + auto & from = dynamic_cast(*sel.e); + from.displ += jAttrs->inheritFromExprs->size(); + } + attrPath.emplace_back(AttrName(ad.first)); + addAttr(jAttrs, attrPath, ad.first, std::move(ad.second)); + attrPath.pop_back(); + } + ae->attrs.clear(); + jAttrs->dynamicAttrs.insert(jAttrs->dynamicAttrs.end(), + std::make_move_iterator(ae->dynamicAttrs.begin()), + std::make_move_iterator(ae->dynamicAttrs.end())); + ae->dynamicAttrs.clear(); + if (ae->inheritFromExprs) { + jAttrs->inheritFromExprs->insert(jAttrs->inheritFromExprs->end(), + std::make_move_iterator(ae->inheritFromExprs->begin()), + std::make_move_iterator(ae->inheritFromExprs->end())); + ae->inheritFromExprs = nullptr; + } + } else { + dupAttr(attrPath, def.pos, j->second.pos); + } + } else { + // This attr path is not defined. Let's create it. + attrs->attrs.emplace(symbol, def); + def.e->setName(symbol); + } +} + inline Formals * ParserState::validateFormals(Formals * formals, PosIdx pos, Symbol arg) { std::sort(formals->formals.begin(), formals->formals.end(), diff --git a/tests/functional/lang/parse-fail-mixed-nested-attrs1.err.exp b/tests/functional/lang/parse-fail-mixed-nested-attrs1.err.exp index a4472156b..49a07323f 100644 --- a/tests/functional/lang/parse-fail-mixed-nested-attrs1.err.exp +++ b/tests/functional/lang/parse-fail-mixed-nested-attrs1.err.exp @@ -1,6 +1,6 @@ -error: attribute 'z' already defined at «stdin»:3:16 - at «stdin»:2:3: - 1| { +error: attribute 'x.z' already defined at «stdin»:2:3 + at «stdin»:3:16: 2| x.z = 3; - | ^ 3| x = { y = 3; z = 3; }; + | ^ + 4| } diff --git a/tests/functional/lang/parse-fail-mixed-nested-attrs2.err.exp b/tests/functional/lang/parse-fail-mixed-nested-attrs2.err.exp index ead1f0dbd..36fab2fe6 100644 --- a/tests/functional/lang/parse-fail-mixed-nested-attrs2.err.exp +++ b/tests/functional/lang/parse-fail-mixed-nested-attrs2.err.exp @@ -1,6 +1,6 @@ -error: attribute 'y' already defined at «stdin»:3:9 - at «stdin»:2:3: - 1| { +error: attribute 'x.y.y' already defined at «stdin»:2:3 + at «stdin»:3:9: 2| x.y.y = 3; - | ^ 3| x = { y.y= 3; z = 3; }; + | ^ + 4| } diff --git a/tests/unit/libexpr/trivial.cc b/tests/unit/libexpr/trivial.cc index e455a571b..226b75be8 100644 --- a/tests/unit/libexpr/trivial.cc +++ b/tests/unit/libexpr/trivial.cc @@ -177,6 +177,48 @@ namespace nix { ) ); +#define X_EXPAND_IF0(k, v) k "." v +#define X_EXPAND_IF1(k, v) k " = { " v " };" +#define X4(w, x, y, z) \ + TEST_F(TrivialExpressionTest, nestedAttrsetMerge##w##x##y##z) { \ + auto v = eval("{ a.b = { c = 1; d = 2; }; } == { " \ + X_EXPAND_IF##w("a", X_EXPAND_IF##x("b","c = 1;")) " " \ + X_EXPAND_IF##y("a", X_EXPAND_IF##z("b","d = 2;")) " }"); \ + ASSERT_THAT(v, IsTrue()); \ + }; \ + TEST_F(TrivialExpressionTest, nestedAttrsetMergeDup##w##x##y##z) { \ + ASSERT_THROW(eval("{ " \ + X_EXPAND_IF##w("a", X_EXPAND_IF##x("b","c = 1;")) " " \ + X_EXPAND_IF##y("a", X_EXPAND_IF##z("b","c = 2;")) " }"), Error); \ + }; \ + TEST_F(TrivialExpressionTest, nestedAttrsetMergeLet##w##x##y##z) { \ + auto v = eval("{ b = { c = 1; d = 2; }; } == (let " \ + X_EXPAND_IF##w("a", X_EXPAND_IF##x("b","c = 1;")) " " \ + X_EXPAND_IF##y("a", X_EXPAND_IF##z("b","d = 2;")) " in a)"); \ + ASSERT_THAT(v, IsTrue()); \ + }; +#define X3(...) X4(__VA_ARGS__, 0) X4(__VA_ARGS__, 1) +#define X2(...) X3(__VA_ARGS__, 0) X3(__VA_ARGS__, 1) +#define X1(...) X2(__VA_ARGS__, 0) X2(__VA_ARGS__, 1) + X1(0) X1(1) +#undef X_EXPAND_IF0 +#undef X_EXPAND_IF1 +#undef X1 +#undef X2 +#undef X3 +#undef X4 + + // This is for backwards compatibility, not because we like it. + // See https://github.com/NixOS/nix/issues/9020. + TEST_F(TrivialExpressionTest, regrettableRecAttrsetMerge) { + auto v = eval("{ a = rec { b = c + 1; d = 2; }; a.c = d + 3; }.a.b"); + ASSERT_THAT(v, IsIntEq(6)); + } + + TEST_F(TrivialExpressionTest, attrsetMergeDropsLaterRec) { + ASSERT_THROW(eval("{ a.b = 1; a = rec { c = d + 2; d = 3; }; }.c"), Error); + } + TEST_F(TrivialExpressionTest, functor) { auto v = eval("{ __functor = self: arg: self.v + arg; v = 10; } 5"); ASSERT_THAT(v, IsIntEq(15));