Merge pull request #7811 from Et7f3/fix_memory_leaks

Reduce memory leaks

src/libexpr/nixexpr.hh

@@ -186,7 +186,7 @@ struct ExprString : Expr
 {
  std::string s;
  Value v;
- ExprString(std::string s) : s(std::move(s)) { v.mkString(this->s.data()); };
+ ExprString(std::string &&s) : s(std::move(s)) { v.mkString(this->s.data()); };
  Value * maybeThunk(EvalState & state, Env & env) override;
  COMMON_METHODS
 };
@@ -233,7 +233,7 @@ struct ExprSelect : Expr
  PosIdx pos;
  Expr * e, * def;
  AttrPath attrPath;
- ExprSelect(const PosIdx & pos, Expr * e, const AttrPath & attrPath, Expr * def) : pos(pos), e(e), def(def), attrPath(attrPath) { };
+ ExprSelect(const PosIdx & pos, Expr * e, const AttrPath && attrPath, Expr * def) : pos(pos), e(e), def(def), attrPath(std::move(attrPath)) { };
  ExprSelect(const PosIdx & pos, Expr * e, Symbol name) : pos(pos), e(e), def(0) { attrPath.push_back(AttrName(name)); };
  PosIdx getPos() const override { return pos; }
  COMMON_METHODS
@@ -243,7 +243,7 @@ struct ExprOpHasAttr : Expr
 {
  Expr * e;
  AttrPath attrPath;
- ExprOpHasAttr(Expr * e, const AttrPath & attrPath) : e(e), attrPath(attrPath) { };
+ ExprOpHasAttr(Expr * e, const AttrPath && attrPath) : e(e), attrPath(std::move(attrPath)) { };
  PosIdx getPos() const override { return e->getPos(); }
  COMMON_METHODS
 };

src/libexpr/parser.y

@@ -90,7 +90,7 @@ static void dupAttr(const EvalState & state, Symbol attr, const PosIdx pos, cons
 }
 
 
-static void addAttr(ExprAttrs * attrs, AttrPath & attrPath,
+static void addAttr(ExprAttrs * attrs, AttrPath && attrPath,
  Expr * e, const PosIdx pos, const nix::EvalState & state)
 {
  AttrPath::iterator i;
@@ -188,7 +188,7 @@ static Formals * toFormals(ParseData & data, ParserFormals * formals,
 
 
 static Expr * stripIndentation(const PosIdx pos, SymbolTable & symbols,
- std::vector<std::pair<PosIdx, std::variant<Expr *, StringToken>>> & es)
+ std::vector<std::pair<PosIdx, std::variant<Expr *, StringToken>>> && es)
 {
  if (es.empty()) return new ExprString("");
 
@@ -268,7 +268,7 @@ static Expr * stripIndentation(const PosIdx pos, SymbolTable & symbols,
  s2 = std::string(s2, 0, p + 1);
  }
 
- es2->emplace_back(i->first, new ExprString(s2));
+ es2->emplace_back(i->first, new ExprString(std::move(s2)));
  };
  for (; i != es.end(); ++i, --n) {
  std::visit(overloaded { trimExpr, trimString }, i->second);
@@ -408,7 +408,7 @@ expr_op
  | expr_op OR expr_op { $$ = new ExprOpOr(makeCurPos(@2, data), $1, $3); }
  | expr_op IMPL expr_op { $$ = new ExprOpImpl(makeCurPos(@2, data), $1, $3); }
  | expr_op UPDATE expr_op { $$ = new ExprOpUpdate(makeCurPos(@2, data), $1, $3); }
- | expr_op '?' attrpath { $$ = new ExprOpHasAttr($1, *$3); }
+ | expr_op '?' attrpath { $$ = new ExprOpHasAttr($1, std::move(*$3)); delete $3; }
  | expr_op '+' expr_op
  { $$ = new ExprConcatStrings(makeCurPos(@2, data), false, new std::vector<std::pair<PosIdx, Expr *> >({{makeCurPos(@1, data), $1}, {makeCurPos(@3, data), $3}})); }
  | expr_op '-' expr_op { $$ = new ExprCall(makeCurPos(@2, data), new ExprVar(data->symbols.create("__sub")), {$1, $3}); }
@@ -431,14 +431,14 @@ expr_app
 
 expr_select
  : expr_simple '.' attrpath
- { $$ = new ExprSelect(CUR_POS, $1, *$3, 0); }
+ { $$ = new ExprSelect(CUR_POS, $1, std::move(*$3), nullptr); delete $3; }
  | expr_simple '.' attrpath OR_KW expr_select
- { $$ = new ExprSelect(CUR_POS, $1, *$3, $5); }
+ { $$ = new ExprSelect(CUR_POS, $1, std::move(*$3), $5); delete $3; }
  | /* Backwards compatibility: because Nixpkgs has a rarely used
  function named ‘or’, allow stuff like ‘map or [...]’. */
  expr_simple OR_KW
  { $$ = new ExprCall(CUR_POS, $1, {new ExprVar(CUR_POS, data->symbols.create("or"))}); }
- | expr_simple { $$ = $1; }
+ | expr_simple
  ;
 
 expr_simple
@@ -453,9 +453,10 @@ expr_simple
  | FLOAT { $$ = new ExprFloat($1); }
  | '"' string_parts '"' { $$ = $2; }
  | IND_STRING_OPEN ind_string_parts IND_STRING_CLOSE {
- $$ = stripIndentation(CUR_POS, data->symbols, *$2);
+ $$ = stripIndentation(CUR_POS, data->symbols, std::move(*$2));
+ delete $2;
  }
- | path_start PATH_END { $$ = $1; }
+ | path_start PATH_END
  | path_start string_parts_interpolated PATH_END {
  $2->insert($2->begin(), {makeCurPos(@1, data), $1});
  $$ = new ExprConcatStrings(CUR_POS, false, $2);
@@ -465,7 +466,7 @@ expr_simple
  $$ = new ExprCall(CUR_POS,
  new ExprVar(data->symbols.create("__findFile")),
  {new ExprVar(data->symbols.create("__nixPath")),
- new ExprString(path)});
+ new ExprString(std::move(path))});
  }
  | URI {
  static bool noURLLiterals = settings.isExperimentalFeatureEnabled(Xp::NoUrlLiterals);
@@ -533,7 +534,7 @@ ind_string_parts
  ;
 
 binds
- : binds attrpath '=' expr ';' { $$ = $1; addAttr($$, *$2, $4, makeCurPos(@2, data), data->state); }
+ : binds attrpath '=' expr ';' { $$ = $1; addAttr($$, std::move(*$2), $4, makeCurPos(@2, data), data->state); delete $2; }
  | binds INHERIT attrs ';'
  { $$ = $1;
  for (auto & i : *$3) {
@@ -542,6 +543,7 @@ binds
  auto pos = makeCurPos(@3, data);
  $$->attrs.emplace(i.symbol, ExprAttrs::AttrDef(new ExprVar(CUR_POS, i.symbol), pos, true));
  }
+ delete $3;
  }
  | binds INHERIT '(' expr ')' attrs ';'
  { $$ = $1;
@@ -551,6 +553,7 @@ binds
  dupAttr(data->state, i.symbol, makeCurPos(@6, data), $$->attrs[i.symbol].pos);
  $$->attrs.emplace(i.symbol, ExprAttrs::AttrDef(new ExprSelect(CUR_POS, $4, i.symbol), makeCurPos(@6, data)));
  }
+ delete $6;
  }
  | { $$ = new ExprAttrs(makeCurPos(@0, data)); }
  ;
@@ -596,7 +599,7 @@ attrpath
  ;
 
 attr
- : ID { $$ = $1; }
+ : ID
  | OR_KW { $$ = {"or", 2}; }
  ;
 
@@ -612,9 +615,9 @@ expr_list
 
 formals
  : formal ',' formals
- { $$ = $3; $$->formals.push_back(*$1); }
+ { $$ = $3; $$->formals.emplace_back(*$1); delete $1; }
  | formal
- { $$ = new ParserFormals; $$->formals.push_back(*$1); $$->ellipsis = false; }
+ { $$ = new ParserFormals; $$->formals.emplace_back(*$1); $$->ellipsis = false; delete $1; }
  |
  { $$ = new ParserFormals; $$->ellipsis = false; }
  | ELLIPSIS