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Merge pull request #9582 from pennae/misc-opts

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a packet of small optimizations
This commit is contained in:
Robert Hensing 2023-12-22 17:00:59 +01:00 • committed by GitHub
commit ee439734e9
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20 changed files with 148 additions and 76 deletions
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14
src/libexpr/eval-inline.hh
View file

@ -83,13 +83,6 @@ Env & EvalState::allocEnv(size_t size)
[[gnu::always_inline]]
void EvalState::forceValue(Value & v, const PosIdx pos)
{
forceValue(v, [&]() { return pos; });
}
template<typename Callable>
void EvalState::forceValue(Value & v, Callable getPos)
{
if (v.isThunk()) {
Env * env = v.thunk.env;
@ -100,15 +93,12 @@ void EvalState::forceValue(Value & v, Callable getPos)
expr->eval(*this, *env, v);
} catch (...) {
v.mkThunk(env, expr);
tryFixupBlackHolePos(v, pos);
throw;
}
}
else if (v.isApp()) {
PosIdx pos = getPos();
else if (v.isApp())
callFunction(*v.app.left, *v.app.right, v, pos);
}
else if (v.isBlackhole())
error("infinite recursion encountered").atPos(getPos()).template debugThrow<EvalError>();
}

67
src/libexpr/eval.cc
View file

@ -163,7 +163,17 @@ void Value::print(const SymbolTable &symbols, std::ostream &str,
break;
case tThunk:
case tApp:
str << "<CODE>";
if (!isBlackhole()) {
str << "<CODE>";
} else {
// Although we know for sure that it's going to be an infinite recursion
// when this value is accessed _in the current context_, it's likely
// that the user will misinterpret a simpler «infinite recursion» output
// as a definitive statement about the value, while in fact it may be
// a valid value after `builtins.trace` and perhaps some other steps
// have completed.
str << "«potential infinite recursion»";
}
break;
case tLambda:
str << "<LAMBDA>";
@ -180,15 +190,6 @@ void Value::print(const SymbolTable &symbols, std::ostream &str,
case tFloat:
str << fpoint;
break;
case tBlackhole:
// Although we know for sure that it's going to be an infinite recursion
// when this value is accessed _in the current context_, it's likely
// that the user will misinterpret a simpler «infinite recursion» output
// as a definitive statement about the value, while in fact it may be
// a valid value after `builtins.trace` and perhaps some other steps
// have completed.
str << "«potential infinite recursion»";
break;
default:
printError("Nix evaluator internal error: Value::print(): invalid value type %1%", internalType);
abort();
@ -256,9 +257,8 @@ std::string showType(const Value & v)
case tPrimOpApp:
return fmt("the partially applied built-in function '%s'", std::string(getPrimOp(v)->primOp->name));
case tExternal: return v.external->showType();
case tThunk: return "a thunk";
case tThunk: return v.isBlackhole() ? "a black hole" : "a thunk";
case tApp: return "a function application";
case tBlackhole: return "a black hole";
default:
return std::string(showType(v.type()));
}
@ -1646,15 +1646,15 @@ void EvalState::callFunction(Value & fun, size_t nrArgs, Value * * args, Value &
return;
} else {
/* We have all the arguments, so call the primop. */
auto name = vCur.primOp->name;
auto * fn = vCur.primOp;
nrPrimOpCalls++;
if (countCalls) primOpCalls[name]++;
if (countCalls) primOpCalls[fn->name]++;
try {
vCur.primOp->fun(*this, vCur.determinePos(noPos), args, vCur);
fn->fun(*this, vCur.determinePos(noPos), args, vCur);
} catch (Error & e) {
addErrorTrace(e, pos, "while calling the '%1%' builtin", name);
addErrorTrace(e, pos, "while calling the '%1%' builtin", fn->name);
throw;
}
@ -1691,18 +1691,18 @@ void EvalState::callFunction(Value & fun, size_t nrArgs, Value * * args, Value &
for (size_t i = 0; i < argsLeft; ++i)
vArgs[argsDone + i] = args[i];
auto name = primOp->primOp->name;
auto fn = primOp->primOp;
nrPrimOpCalls++;
if (countCalls) primOpCalls[name]++;
if (countCalls) primOpCalls[fn->name]++;
try {
// TODO:
// 1. Unify this and above code. Heavily redundant.
// 2. Create a fake env (arg1, arg2, etc.) and a fake expr (arg1: arg2: etc: builtins.name arg1 arg2 etc)
// so the debugger allows to inspect the wrong parameters passed to the builtin.
primOp->primOp->fun(*this, vCur.determinePos(noPos), vArgs, vCur);
fn->fun(*this, vCur.determinePos(noPos), vArgs, vCur);
} catch (Error & e) {
addErrorTrace(e, pos, "while calling the '%1%' builtin", name);
addErrorTrace(e, pos, "while calling the '%1%' builtin", fn->name);
throw;
}
@ -2056,6 +2056,29 @@ void ExprPos::eval(EvalState & state, Env & env, Value & v)
}
void ExprBlackHole::eval(EvalState & state, Env & env, Value & v)
{
state.error("infinite recursion encountered")
.debugThrow<InfiniteRecursionError>();
}
// always force this to be separate, otherwise forceValue may inline it and take
// a massive perf hit
[[gnu::noinline]]
void EvalState::tryFixupBlackHolePos(Value & v, PosIdx pos)
{
if (!v.isBlackhole())
return;
auto e = std::current_exception();
try {
std::rethrow_exception(e);
} catch (InfiniteRecursionError & e) {
e.err.errPos = positions[pos];
} catch (...) {
}
}
void EvalState::forceValueDeep(Value & v)
{
std::set<const Value *> seen;
@ -2065,7 +2088,7 @@ void EvalState::forceValueDeep(Value & v)
recurse = [&](Value & v) {
if (!seen.insert(&v).second) return;
forceValue(v, [&]() { return v.determinePos(noPos); });
forceValue(v, v.determinePos(noPos));
if (v.type() == nAttrs) {
for (auto & i : *v.attrs)
@ -2457,7 +2480,7 @@ bool EvalState::eqValues(Value & v1, Value & v2, const PosIdx pos, std::string_v
return v1.boolean == v2.boolean;
case nString:
return v1.string_view().compare(v2.string_view()) == 0;
return strcmp(v1.c_str(), v2.c_str()) == 0;
case nPath:
return

3
src/libexpr/eval.hh
View file

@ -460,8 +460,7 @@ public:
*/
inline void forceValue(Value & v, const PosIdx pos);
template <typename Callable>
inline void forceValue(Value & v, Callable getPos);
void tryFixupBlackHolePos(Value & v, PosIdx pos);
/**
* Force a value, then recursively force list elements and

4
src/libexpr/get-drvs.cc
View file

@ -198,7 +198,7 @@ StringSet DrvInfo::queryMetaNames()
bool DrvInfo::checkMeta(Value & v)
{
state->forceValue(v, [&]() { return v.determinePos(noPos); });
state->forceValue(v, v.determinePos(noPos));
if (v.type() == nList) {
for (auto elem : v.listItems())
if (!checkMeta(*elem)) return false;
@ -304,7 +304,7 @@ static bool getDerivation(EvalState & state, Value & v,
bool ignoreAssertionFailures)
{
try {
state.forceValue(v, [&]() { return v.determinePos(noPos); });
state.forceValue(v, v.determinePos(noPos));
if (!state.isDerivation(v)) return true;
/* Remove spurious duplicates (e.g., a set like `rec { x =

10
src/libexpr/lexer.l
View file

@ -1,4 +1,5 @@
%option reentrant bison-bridge bison-locations
%option align
%option noyywrap
%option never-interactive
%option stack
@ -35,9 +36,6 @@ static inline PosIdx makeCurPos(const YYLTYPE & loc, ParseData * data)
#define CUR_POS makeCurPos(*yylloc, data)
// backup to recover from yyless(0)
thread_local YYLTYPE prev_yylloc;
static void initLoc(YYLTYPE * loc)
{
loc->first_line = loc->last_line = 1;
@ -46,7 +44,7 @@ static void initLoc(YYLTYPE * loc)
static void adjustLoc(YYLTYPE * loc, const char * s, size_t len)
{
prev_yylloc = *loc;
loc->stash();
loc->first_line = loc->last_line;
loc->first_column = loc->last_column;
@ -230,7 +228,7 @@ or { return OR_KW; }
{HPATH_START}\$\{ {
PUSH_STATE(PATH_START);
yyless(0);
*yylloc = prev_yylloc;
yylloc->unstash();
}
<PATH_START>{PATH_SEG} {
@ -286,7 +284,7 @@ or { return OR_KW; }
context (it may be ')', ';', or something of that sort) */
POP_STATE();
yyless(0);
*yylloc = prev_yylloc;
yylloc->unstash();
return PATH_END;
}

2
src/libexpr/nixexpr.cc
View file

@ -9,6 +9,8 @@
namespace nix {
ExprBlackHole eBlackHole;
struct PosAdapter : AbstractPos
{
Pos::Origin origin;

17
src/libexpr/nixexpr.hh
View file

@ -21,6 +21,13 @@ MakeError(TypeError, EvalError);
MakeError(UndefinedVarError, Error);
MakeError(MissingArgumentError, EvalError);
class InfiniteRecursionError : public EvalError
{
friend class EvalState;
public:
using EvalError::EvalError;
};
/**
* Position objects.
*/
@ -455,6 +462,16 @@ struct ExprPos : Expr
COMMON_METHODS
};
/* only used to mark thunks as black holes. */
struct ExprBlackHole : Expr
{
void show(const SymbolTable & symbols, std::ostream & str) const override {}
void eval(EvalState & state, Env & env, Value & v) override;
void bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env) override {}
};
extern ExprBlackHole eBlackHole;
/* Static environments are used to map variable names onto (level,
displacement) pairs used to obtain the value of the variable at

25
src/libexpr/parser.y
View file

@ -28,6 +28,31 @@
namespace nix {
#define YYLTYPE ::nix::ParserLocation
struct ParserLocation
{
int first_line, first_column;
int last_line, last_column;
// backup to recover from yyless(0)
int stashed_first_line, stashed_first_column;
int stashed_last_line, stashed_last_column;
void stash() {
stashed_first_line = first_line;
stashed_first_column = first_column;
stashed_last_line = last_line;
stashed_last_column = last_column;
}
void unstash() {
first_line = stashed_first_line;
first_column = stashed_first_column;
last_line = stashed_last_line;
last_column = stashed_last_column;
}
};
struct ParseData
{
EvalState & state;

4
src/libexpr/primops.cc
View file

@ -584,7 +584,7 @@ struct CompareValues
case nFloat:
return v1->fpoint < v2->fpoint;
case nString:
return v1->string_view().compare(v2->string_view()) < 0;
return strcmp(v1->c_str(), v2->c_str()) < 0;
case nPath:
// Note: we don't take the accessor into account
// since it's not obvious how to compare them in a
@ -2405,7 +2405,7 @@ static void prim_attrNames(EvalState & state, const PosIdx pos, Value * * args,
(v.listElems()[n++] = state.allocValue())->mkString(state.symbols[i.name]);
std::sort(v.listElems(), v.listElems() + n,
[](Value * v1, Value * v2) { return v1->string_view().compare(v2->string_view()) < 0; });
[](Value * v1, Value * v2) { return strcmp(v1->c_str(), v2->c_str()) < 0; });
}
static RegisterPrimOp primop_attrNames({

26
src/libexpr/value.hh
View file

@ -32,7 +32,6 @@ typedef enum {
tThunk,
tApp,
tLambda,
tBlackhole,
tPrimOp,
tPrimOpApp,
tExternal,
@ -62,6 +61,7 @@ class Bindings;
struct Env;
struct Expr;
struct ExprLambda;
struct ExprBlackHole;
struct PrimOp;
class Symbol;
class PosIdx;
@ -151,7 +151,7 @@ public:
// type() == nThunk
inline bool isThunk() const { return internalType == tThunk; };
inline bool isApp() const { return internalType == tApp; };
inline bool isBlackhole() const { return internalType == tBlackhole; };
inline bool isBlackhole() const;
// type() == nFunction
inline bool isLambda() const { return internalType == tLambda; };
@ -248,7 +248,7 @@ public:
case tLambda: case tPrimOp: case tPrimOpApp: return nFunction;
case tExternal: return nExternal;
case tFloat: return nFloat;
case tThunk: case tApp: case tBlackhole: return nThunk;
case tThunk: case tApp: return nThunk;
}
if (invalidIsThunk)
return nThunk;
@ -356,11 +356,7 @@ public:
lambda.fun = f;
}
inline void mkBlackhole()
{
internalType = tBlackhole;
// Value will be overridden anyways
}
inline void mkBlackhole();
void mkPrimOp(PrimOp * p);
@ -447,6 +443,20 @@ public:
};
extern ExprBlackHole eBlackHole;
bool Value::isBlackhole() const
{
return internalType == tThunk && thunk.expr == (Expr*) &eBlackHole;
}
void Value::mkBlackhole()
{
internalType = tThunk;
thunk.expr = (Expr*) &eBlackHole;
}
#if HAVE_BOEHMGC
typedef std::vector<Value *, traceable_allocator<Value *>> ValueVector;
typedef std::map<Symbol, Value *, std::less<Symbol>, traceable_allocator<std::pair<const Symbol, Value *>>> ValueMap;