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-rw-r--r--src/libcmd/repl.cc2
-rw-r--r--src/libexpr/eval-inline.hh2
-rw-r--r--src/libexpr/eval.cc29
-rw-r--r--src/libexpr/eval.hh5
-rw-r--r--src/libexpr/nixexpr.cc18
-rw-r--r--src/libexpr/nixexpr.hh13
-rw-r--r--src/libexpr/primops.cc2
7 files changed, 37 insertions, 34 deletions
diff --git a/src/libcmd/repl.cc b/src/libcmd/repl.cc
index e6f0faa06..d25ad582e 100644
--- a/src/libcmd/repl.cc
+++ b/src/libcmd/repl.cc
@@ -109,7 +109,7 @@ NixRepl::NixRepl(const SearchPath & searchPath, nix::ref<Store> store, ref<EvalS
: AbstractNixRepl(state)
, debugTraceIndex(0)
, getValues(getValues)
- , staticEnv(new StaticEnv(false, state->staticBaseEnv.get()))
+ , staticEnv(new StaticEnv(nullptr, state->staticBaseEnv.get()))
, historyFile(getDataDir() + "/nix/repl-history")
{
}
diff --git a/src/libexpr/eval-inline.hh b/src/libexpr/eval-inline.hh
index 52aa75b5f..f7710f819 100644
--- a/src/libexpr/eval-inline.hh
+++ b/src/libexpr/eval-inline.hh
@@ -73,8 +73,6 @@ Env & EvalState::allocEnv(size_t size)
#endif
env = (Env *) allocBytes(sizeof(Env) + size * sizeof(Value *));
- env->type = Env::Plain;
-
/* We assume that env->values has been cleared by the allocator; maybeThunk() and lookupVar fromWith expect this. */
return *env;
diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc
index deb5ea2b3..0fa686701 100644
--- a/src/libexpr/eval.cc
+++ b/src/libexpr/eval.cc
@@ -519,7 +519,7 @@ EvalState::EvalState(
, env1AllocCache(std::allocate_shared<void *>(traceable_allocator<void *>(), nullptr))
#endif
, baseEnv(allocEnv(128))
- , staticBaseEnv{std::make_shared<StaticEnv>(false, nullptr)}
+ , staticBaseEnv{std::make_shared<StaticEnv>(nullptr, nullptr)}
{
countCalls = getEnv("NIX_COUNT_CALLS").value_or("0") != "0";
@@ -788,7 +788,7 @@ void printStaticEnvBindings(const SymbolTable & st, const StaticEnv & se)
// just for the current level of Env, not the whole chain.
void printWithBindings(const SymbolTable & st, const Env & env)
{
- if (env.type == Env::HasWithAttrs) {
+ if (!env.values[0]->isThunk()) {
std::cout << "with: ";
std::cout << ANSI_MAGENTA;
Bindings::iterator j = env.values[0]->attrs->begin();
@@ -842,7 +842,7 @@ void mapStaticEnvBindings(const SymbolTable & st, const StaticEnv & se, const En
if (env.up && se.up) {
mapStaticEnvBindings(st, *se.up, *env.up, vm);
- if (env.type == Env::HasWithAttrs) {
+ if (!env.values[0]->isThunk()) {
// add 'with' bindings.
Bindings::iterator j = env.values[0]->attrs->begin();
while (j != env.values[0]->attrs->end()) {
@@ -980,22 +980,23 @@ inline Value * EvalState::lookupVar(Env * env, const ExprVar & var, bool noEval)
if (!var.fromWith) return env->values[var.displ];
+ // This early exit defeats the `maybeThunk` optimization for variables from `with`,
+ // The added complexity of handling this appears to be similarly in cost, or
+ // the cases where applicable were insignificant in the first place.
+ if (noEval) return nullptr;
+
+ auto * fromWith = var.fromWith;
while (1) {
- if (env->type == Env::HasWithExpr) {
- if (noEval) return 0;
- Value * v = allocValue();
- evalAttrs(*env->up, (Expr *) env->values[0], *v, noPos, "<borked>");
- env->values[0] = v;
- env->type = Env::HasWithAttrs;
- }
+ forceAttrs(*env->values[0], fromWith->pos, "while evaluating the first subexpression of a with expression");
Bindings::iterator j = env->values[0]->attrs->find(var.name);
if (j != env->values[0]->attrs->end()) {
if (countCalls) attrSelects[j->pos]++;
return j->value;
}
- if (!env->prevWith)
+ if (!fromWith->parentWith)
error("undefined variable '%1%'", symbols[var.name]).atPos(var.pos).withFrame(*env, var).debugThrow<UndefinedVarError>();
- for (size_t l = env->prevWith; l; --l, env = env->up) ;
+ for (size_t l = fromWith->prevWith; l; --l, env = env->up) ;
+ fromWith = fromWith->parentWith;
}
}
@@ -1854,9 +1855,7 @@ void ExprWith::eval(EvalState & state, Env & env, Value & v)
{
Env & env2(state.allocEnv(1));
env2.up = &env;
- env2.prevWith = prevWith;
- env2.type = Env::HasWithExpr;
- env2.values[0] = (Value *) attrs;
+ env2.values[0] = attrs->maybeThunk(state, env);
body->eval(state, env2, v);
}
diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh
index 4cbd45013..6adf6d066 100644
--- a/src/libexpr/eval.hh
+++ b/src/libexpr/eval.hh
@@ -115,11 +115,6 @@ struct Constant
struct Env
{
Env * up;
- /**
- * Number of of levels up to next `with` environment
- */
- unsigned short prevWith:14;
- enum { Plain = 0, HasWithExpr, HasWithAttrs } type:2;
Value * values[0];
};
diff --git a/src/libexpr/nixexpr.cc b/src/libexpr/nixexpr.cc
index 76ce62f6c..edab297f2 100644
--- a/src/libexpr/nixexpr.cc
+++ b/src/libexpr/nixexpr.cc
@@ -333,6 +333,8 @@ void ExprVar::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> &
if (es.debugRepl)
es.exprEnvs.insert(std::make_pair(this, env));
+ fromWith = nullptr;
+
/* Check whether the variable appears in the environment. If so,
set its level and displacement. */
const StaticEnv * curEnv;
@@ -344,7 +346,6 @@ void ExprVar::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> &
} else {
auto i = curEnv->find(name);
if (i != curEnv->vars.end()) {
- fromWith = false;
this->level = level;
displ = i->second;
return;
@@ -360,7 +361,8 @@ void ExprVar::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> &
.msg = hintfmt("undefined variable '%1%'", es.symbols[name]),
.errPos = es.positions[pos]
});
- fromWith = true;
+ for (auto * e = env.get(); e && !fromWith; e = e->up)
+ fromWith = e->isWith;
this->level = withLevel;
}
@@ -393,7 +395,7 @@ void ExprAttrs::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv>
es.exprEnvs.insert(std::make_pair(this, env));
if (recursive) {
- auto newEnv = std::make_shared<StaticEnv>(false, env.get(), recursive ? attrs.size() : 0);
+ auto newEnv = std::make_shared<StaticEnv>(nullptr, env.get(), recursive ? attrs.size() : 0);
Displacement displ = 0;
for (auto & i : attrs)
@@ -435,7 +437,7 @@ void ExprLambda::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv>
es.exprEnvs.insert(std::make_pair(this, env));
auto newEnv = std::make_shared<StaticEnv>(
- false, env.get(),
+ nullptr, env.get(),
(hasFormals() ? formals->formals.size() : 0) +
(!arg ? 0 : 1));
@@ -471,7 +473,7 @@ void ExprLet::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> &
if (es.debugRepl)
es.exprEnvs.insert(std::make_pair(this, env));
- auto newEnv = std::make_shared<StaticEnv>(false, env.get(), attrs->attrs.size());
+ auto newEnv = std::make_shared<StaticEnv>(nullptr, env.get(), attrs->attrs.size());
Displacement displ = 0;
for (auto & i : attrs->attrs)
@@ -490,6 +492,10 @@ void ExprWith::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> &
if (es.debugRepl)
es.exprEnvs.insert(std::make_pair(this, env));
+ parentWith = nullptr;
+ for (auto * e = env.get(); e && !parentWith; e = e->up)
+ parentWith = e->isWith;
+
/* Does this `with' have an enclosing `with'? If so, record its
level so that `lookupVar' can look up variables in the previous
`with' if this one doesn't contain the desired attribute. */
@@ -506,7 +512,7 @@ void ExprWith::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> &
es.exprEnvs.insert(std::make_pair(this, env));
attrs->bindVars(es, env);
- auto newEnv = std::make_shared<StaticEnv>(true, env.get());
+ auto newEnv = std::make_shared<StaticEnv>(this, env.get());
body->bindVars(es, newEnv);
}
diff --git a/src/libexpr/nixexpr.hh b/src/libexpr/nixexpr.hh
index cb952f5bb..2b5b72bc0 100644
--- a/src/libexpr/nixexpr.hh
+++ b/src/libexpr/nixexpr.hh
@@ -139,6 +139,7 @@ std::ostream & operator << (std::ostream & str, const Pos & pos);
struct Env;
struct Value;
class EvalState;
+struct ExprWith;
struct StaticEnv;
@@ -221,8 +222,11 @@ struct ExprVar : Expr
Symbol name;
/* Whether the variable comes from an environment (e.g. a rec, let
- or function argument) or from a "with". */
- bool fromWith;
+ or function argument) or from a "with".
+
+ `nullptr`: Not from a `with`.
+ Valid pointer: the nearest, innermost `with` expression to query first. */
+ ExprWith * fromWith;
/* In the former case, the value is obtained by going `level`
levels up from the current environment and getting the
@@ -380,6 +384,7 @@ struct ExprWith : Expr
PosIdx pos;
Expr * attrs, * body;
size_t prevWith;
+ ExprWith * parentWith;
ExprWith(const PosIdx & pos, Expr * attrs, Expr * body) : pos(pos), attrs(attrs), body(body) { };
PosIdx getPos() const override { return pos; }
COMMON_METHODS
@@ -473,14 +478,14 @@ extern ExprBlackHole eBlackHole;
runtime. */
struct StaticEnv
{
- bool isWith;
+ ExprWith * isWith;
const StaticEnv * up;
// Note: these must be in sorted order.
typedef std::vector<std::pair<Symbol, Displacement>> Vars;
Vars vars;
- StaticEnv(bool isWith, const StaticEnv * up, size_t expectedSize = 0) : isWith(isWith), up(up) {
+ StaticEnv(ExprWith * isWith, const StaticEnv * up, size_t expectedSize = 0) : isWith(isWith), up(up) {
vars.reserve(expectedSize);
};
diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index 6c8a1f5a8..e107db228 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -233,7 +233,7 @@ static void import(EvalState & state, const PosIdx pos, Value & vPath, Value * v
Env * env = &state.allocEnv(vScope->attrs->size());
env->up = &state.baseEnv;
- auto staticEnv = std::make_shared<StaticEnv>(false, state.staticBaseEnv.get(), vScope->attrs->size());
+ auto staticEnv = std::make_shared<StaticEnv>(nullptr, state.staticBaseEnv.get(), vScope->attrs->size());
unsigned int displ = 0;
for (auto & attr : *vScope->attrs) {
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-23 20:21:55 +0000