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Rework error throwing, and test it

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This commit is contained in:
Guillaume Maudoux 2022-10-25 01:46:10 +02:00
parent 8bd8583bc7
commit e93bf69b44
8 changed files with 190 additions and 102 deletions
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16
src/libexpr/eval-cache.cc
View file

@ -571,14 +571,14 @@ std::string AttrCursor::getString()
debug("using cached string attribute '%s'", getAttrPathStr()); debug("using cached string attribute '%s'", getAttrPathStr());
return s->first; return s->first;
} else } else
root->state.error<TypeError>("'%s' is not a string", getAttrPathStr()).debugThrow(); root->state.error("'%s' is not a string", getAttrPathStr()).debugThrow<TypeError>();
} }
} }
auto & v = forceValue(); auto & v = forceValue();
if (v.type() != nString && v.type() != nPath) if (v.type() != nString && v.type() != nPath)
root->state.error<TypeError>("'%s' is not a string but %s", getAttrPathStr()).debugThrow(); root->state.error("'%s' is not a string but %s", getAttrPathStr()).debugThrow<TypeError>();
return v.type() == nString ? v.string.s : v.path; return v.type() == nString ? v.string.s : v.path;
} }
@ -602,7 +602,7 @@ string_t AttrCursor::getStringWithContext()
return *s; return *s;
} }
} else } else
root->state.error<TypeError>("'%s' is not a string", getAttrPathStr()).debugThrow(); root->state.error("'%s' is not a string", getAttrPathStr()).debugThrow<TypeError>();
} }
} }
@ -613,7 +613,7 @@ string_t AttrCursor::getStringWithContext()
else if (v.type() == nPath) else if (v.type() == nPath)
return {v.path, {}}; return {v.path, {}};
else else
root->state.error<TypeError>("'%s' is not a string but %s", getAttrPathStr()).debugThrow(); root->state.error("'%s' is not a string but %s", getAttrPathStr()).debugThrow<TypeError>();
} }
bool AttrCursor::getBool() bool AttrCursor::getBool()
@ -626,14 +626,14 @@ bool AttrCursor::getBool()
debug("using cached Boolean attribute '%s'", getAttrPathStr()); debug("using cached Boolean attribute '%s'", getAttrPathStr());
return *b; return *b;
} else } else
root->state.error<TypeError>("'%s' is not a Boolean", getAttrPathStr()).debugThrow(); root->state.error("'%s' is not a Boolean", getAttrPathStr()).debugThrow<TypeError>();
} }
} }
auto & v = forceValue(); auto & v = forceValue();
if (v.type() != nBool) if (v.type() != nBool)
root->state.error<TypeError>("'%s' is not a Boolean", getAttrPathStr()).debugThrow(); root->state.error("'%s' is not a Boolean", getAttrPathStr()).debugThrow<TypeError>();
return v.boolean; return v.boolean;
} }
@ -703,14 +703,14 @@ std::vector<Symbol> AttrCursor::getAttrs()
debug("using cached attrset attribute '%s'", getAttrPathStr()); debug("using cached attrset attribute '%s'", getAttrPathStr());
return *attrs; return *attrs;
} else } else
root->state.error<TypeError>("'%s' is not an attribute set", getAttrPathStr()).debugThrow(); root->state.error("'%s' is not an attribute set", getAttrPathStr()).debugThrow<TypeError>();
} }
} }
auto & v = forceValue(); auto & v = forceValue();
if (v.type() != nAttrs) if (v.type() != nAttrs)
root->state.error<TypeError>("'%s' is not an attribute set", getAttrPathStr()).debugThrow(); root->state.error("'%s' is not an attribute set", getAttrPathStr()).debugThrow<TypeError>();
std::vector<Symbol> attrs; std::vector<Symbol> attrs;
for (auto & attr : *getValue().attrs) for (auto & attr : *getValue().attrs)

6
src/libexpr/eval-inline.hh
View file

@ -103,7 +103,7 @@ void EvalState::forceValue(Value & v, Callable getPos)
else if (v.isApp()) else if (v.isApp())
callFunction(*v.app.left, *v.app.right, v, noPos); callFunction(*v.app.left, *v.app.right, v, noPos);
else if (v.isBlackhole()) else if (v.isBlackhole())
error<EvalError>("infinite recursion encountered").atPos(getPos()).debugThrow(); error("infinite recursion encountered").atPos(getPos()).template debugThrow<EvalError>();
} }
@ -121,7 +121,7 @@ inline void EvalState::forceAttrs(Value & v, Callable getPos, std::string_view e
forceValue(v, noPos); forceValue(v, noPos);
if (v.type() != nAttrs) { if (v.type() != nAttrs) {
PosIdx pos = getPos(); PosIdx pos = getPos();
this->error<TypeError>("value is %1% while a set was expected", showType(v)).withTrace(pos, errorCtx).debugThrow(); error("value is %1% while a set was expected", showType(v)).withTrace(pos, errorCtx).debugThrow<TypeError>();
} }
} }
@ -131,7 +131,7 @@ inline void EvalState::forceList(Value & v, const PosIdx pos, std::string_view e
{ {
forceValue(v, noPos); forceValue(v, noPos);
if (!v.isList()) { if (!v.isList()) {
this->error<TypeError>("value is %1% while a list was expected", showType(v)).withTrace(pos, errorCtx).debugThrow(); error("value is %1% while a list was expected", showType(v)).withTrace(pos, errorCtx).debugThrow<TypeError>();
} }
} }

87
src/libexpr/eval.cc
View file

@ -418,41 +418,30 @@ static Strings parseNixPath(const std::string & s)
return res; return res;
} }
template<class ErrorType> ErrorBuilder & ErrorBuilder::atPos(PosIdx pos)
ErrorBuilder<ErrorType>::ErrorBuilder(EvalState & s):
state(s),
info(ErrorInfo { .msg = hintformat(""), .errPos = std::nullopt, })
{}
template<class ErrorType>
ErrorBuilder<ErrorType> & ErrorBuilder<ErrorType>::atPos(PosIdx pos)
{ {
info.errPos = state.positions[pos]; info.errPos = state.positions[pos];
return *this; return *this;
} }
template<class ErrorType> ErrorBuilder & ErrorBuilder::withTrace(PosIdx pos, const std::string_view text)
ErrorBuilder<ErrorType> & ErrorBuilder<ErrorType>::withTrace(PosIdx pos, const std::string_view text)
{ {
info.traces.push_back(Trace{ .pos = state.positions[pos], .hint = hintformat(std::string(text)), .frame = false }); info.traces.push_front(Trace{ .pos = state.positions[pos], .hint = hintformat(std::string(text)), .frame = false });
return *this; return *this;
} }
template<class ErrorType> ErrorBuilder & ErrorBuilder::withFrameTrace(PosIdx pos, const std::string_view text)
ErrorBuilder<ErrorType> & ErrorBuilder<ErrorType>::withFrameTrace(PosIdx pos, const std::string_view text)
{ {
info.traces.push_back(Trace{ .pos = state.positions[pos], .hint = hintformat(std::string(text)), .frame = true }); info.traces.push_front(Trace{ .pos = state.positions[pos], .hint = hintformat(std::string(text)), .frame = true });
return *this; return *this;
} }
template<class ErrorType> ErrorBuilder & ErrorBuilder::withSuggestions(Suggestions & s) {
ErrorBuilder<ErrorType> & ErrorBuilder<ErrorType>::suggestions(Suggestions & s) {
info.suggestions = s; info.suggestions = s;
return *this; return *this;
} }
template<class ErrorType> ErrorBuilder & ErrorBuilder::withFrame(const Env & env, const Expr & expr) {
ErrorBuilder<ErrorType> & ErrorBuilder<ErrorType>::withFrame(const Env & env, const Expr & expr) {
// NOTE: This is abusing side-effects. // NOTE: This is abusing side-effects.
// TODO: check compatibility with nested debugger calls. // TODO: check compatibility with nested debugger calls.
state.debugTraces.push_front(DebugTrace { state.debugTraces.push_front(DebugTrace {
@ -972,7 +961,7 @@ inline Value * EvalState::lookupVar(Env * env, const ExprVar & var, bool noEval)
return j->value; return j->value;
} }
if (!env->prevWith) if (!env->prevWith)
error<UndefinedVarError>("undefined variable '%1%'", symbols[var.name]).atPos(var.pos).withFrame(*env, var).debugThrow(); 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 = env->prevWith; l; --l, env = env->up) ;
} }
} }
@ -1122,7 +1111,7 @@ void EvalState::cacheFile(
// computation. // computation.
if (mustBeTrivial && if (mustBeTrivial &&
!(dynamic_cast<ExprAttrs *>(e))) !(dynamic_cast<ExprAttrs *>(e)))
error<EvalError>("file '%s' must be an attribute set", path).debugThrow(); error("file '%s' must be an attribute set", path).debugThrow<EvalError>();
eval(e, v); eval(e, v);
} catch (Error & e) { } catch (Error & e) {
addErrorTrace(e, "while evaluating the file '%1%':", resolvedPath); addErrorTrace(e, "while evaluating the file '%1%':", resolvedPath);
@ -1146,7 +1135,7 @@ inline bool EvalState::evalBool(Env & env, Expr * e, const PosIdx pos, std::stri
Value v; Value v;
e->eval(*this, env, v); e->eval(*this, env, v);
if (v.type() != nBool) if (v.type() != nBool)
error<TypeError>("value is %1% while a Boolean was expected", showType(v)).withFrame(env, *e).debugThrow(); error("value is %1% while a Boolean was expected", showType(v)).withFrame(env, *e).debugThrow<TypeError>();
return v.boolean; return v.boolean;
} catch (Error & e) { } catch (Error & e) {
e.addTrace(positions[pos], errorCtx); e.addTrace(positions[pos], errorCtx);
@ -1160,7 +1149,7 @@ inline void EvalState::evalAttrs(Env & env, Expr * e, Value & v, const PosIdx po
try { try {
e->eval(*this, env, v); e->eval(*this, env, v);
if (v.type() != nAttrs) if (v.type() != nAttrs)
error<TypeError>("value is %1% while a set was expected", showType(v)).withFrame(env, *e).debugThrow(); error("value is %1% while a set was expected", showType(v)).withFrame(env, *e).debugThrow<TypeError>();
} catch (Error & e) { } catch (Error & e) {
e.addTrace(positions[pos], errorCtx); e.addTrace(positions[pos], errorCtx);
throw; throw;
@ -1269,7 +1258,7 @@ void ExprAttrs::eval(EvalState & state, Env & env, Value & v)
auto nameSym = state.symbols.create(nameVal.string.s); auto nameSym = state.symbols.create(nameVal.string.s);
Bindings::iterator j = v.attrs->find(nameSym); Bindings::iterator j = v.attrs->find(nameSym);
if (j != v.attrs->end()) if (j != v.attrs->end())
state.error<EvalError>("dynamic attribute '%1%' already defined at %2%", state.symbols[nameSym], state.positions[j->pos]).atPos(i.pos).withFrame(env, *this).debugThrow(); state.error("dynamic attribute '%1%' already defined at %2%", state.symbols[nameSym], state.positions[j->pos]).atPos(i.pos).withFrame(env, *this).debugThrow<EvalError>();
i.valueExpr->setName(nameSym); i.valueExpr->setName(nameSym);
/* Keep sorted order so find can catch duplicates */ /* Keep sorted order so find can catch duplicates */
@ -1372,8 +1361,8 @@ void ExprSelect::eval(EvalState & state, Env & env, Value & v)
for (auto & attr : *vAttrs->attrs) for (auto & attr : *vAttrs->attrs)
allAttrNames.insert(state.symbols[attr.name]); allAttrNames.insert(state.symbols[attr.name]);
auto suggestions = Suggestions::bestMatches(allAttrNames, state.symbols[name]); auto suggestions = Suggestions::bestMatches(allAttrNames, state.symbols[name]);
state.error<EvalError>("attribute '%1%' missing", state.symbols[name]) state.error("attribute '%1%' missing", state.symbols[name])
.atPos(pos).suggestions(suggestions).withFrame(env, *this).debugThrow(); .atPos(pos).withSuggestions(suggestions).withFrame(env, *this).debugThrow<EvalError>();
} }
} }
vAttrs = j->value; vAttrs = j->value;
@ -1483,13 +1472,13 @@ void EvalState::callFunction(Value & fun, size_t nrArgs, Value * * args, Value &
auto j = args[0]->attrs->get(i.name); auto j = args[0]->attrs->get(i.name);
if (!j) { if (!j) {
if (!i.def) { if (!i.def) {
error<TypeError>("function '%1%' called without required argument '%2%'", error("function '%1%' called without required argument '%2%'",
(lambda.name ? std::string(symbols[lambda.name]) : "anonymous lambda"), (lambda.name ? std::string(symbols[lambda.name]) : "anonymous lambda"),
symbols[i.name]) symbols[i.name])
.atPos(lambda.pos) .atPos(lambda.pos)
.withTrace(pos, "from call site") .withTrace(pos, "from call site")
.withFrame(*fun.lambda.env, lambda) .withFrame(*fun.lambda.env, lambda)
.debugThrow(); .debugThrow<TypeError>();
} }
env2.values[displ++] = i.def->maybeThunk(*this, env2); env2.values[displ++] = i.def->maybeThunk(*this, env2);
} else { } else {
@ -1509,14 +1498,14 @@ void EvalState::callFunction(Value & fun, size_t nrArgs, Value * * args, Value &
for (auto & formal : lambda.formals->formals) for (auto & formal : lambda.formals->formals)
formalNames.insert(symbols[formal.name]); formalNames.insert(symbols[formal.name]);
auto suggestions = Suggestions::bestMatches(formalNames, symbols[i.name]); auto suggestions = Suggestions::bestMatches(formalNames, symbols[i.name]);
error<TypeError>("function '%1%' called with unexpected argument '%2%'", error("function '%1%' called with unexpected argument '%2%'",
(lambda.name ? std::string(symbols[lambda.name]) : "anonymous lambda"), (lambda.name ? std::string(symbols[lambda.name]) : "anonymous lambda"),
symbols[i.name]) symbols[i.name])
.atPos(lambda.pos) .atPos(lambda.pos)
.withTrace(pos, "from call site") .withTrace(pos, "from call site")
.suggestions(suggestions) .withSuggestions(suggestions)
.withFrame(*fun.lambda.env, lambda) .withFrame(*fun.lambda.env, lambda)
.debugThrow(); .debugThrow<TypeError>();
} }
abort(); // can't happen abort(); // can't happen
} }
@ -1647,7 +1636,7 @@ void EvalState::callFunction(Value & fun, size_t nrArgs, Value * * args, Value &
} }
else else
error<TypeError>("attempt to call something which is not a function but %1%", showType(vCur)).atPos(pos).debugThrow(); error("attempt to call something which is not a function but %1%", showType(vCur)).atPos(pos).debugThrow<TypeError>();
} }
vRes = vCur; vRes = vCur;
@ -1711,12 +1700,12 @@ void EvalState::autoCallFunction(Bindings & args, Value & fun, Value & res)
if (j != args.end()) { if (j != args.end()) {
attrs.insert(*j); attrs.insert(*j);
} else if (!i.def) { } else if (!i.def) {
error<MissingArgumentError>(R"(cannot evaluate a function that has an argument without a value ('%1%') error(R"(cannot evaluate a function that has an argument without a value ('%1%')
Nix attempted to evaluate a function as a top level expression; in Nix attempted to evaluate a function as a top level expression; in
this case it must have its arguments supplied either by default this case it must have its arguments supplied either by default
values, or passed explicitly with '--arg' or '--argstr'. See values, or passed explicitly with '--arg' or '--argstr'. See
https://nixos.org/manual/nix/stable/expressions/language-constructs.html#functions.)", symbols[i.name]) https://nixos.org/manual/nix/stable/expressions/language-constructs.html#functions.)", symbols[i.name])
.atPos(i.pos).withFrame(*fun.lambda.env, *fun.lambda.fun).debugThrow(); .atPos(i.pos).withFrame(*fun.lambda.env, *fun.lambda.fun).debugThrow<MissingArgumentError>();
} }
} }
} }
@ -1749,7 +1738,7 @@ void ExprAssert::eval(EvalState & state, Env & env, Value & v)
if (!state.evalBool(env, cond, pos, "in the condition of the assert statement")) { if (!state.evalBool(env, cond, pos, "in the condition of the assert statement")) {
std::ostringstream out; std::ostringstream out;
cond->show(state.symbols, out); cond->show(state.symbols, out);
state.error<AssertionError>("assertion '%1%' failed", out.str()).atPos(pos).withFrame(env, *this).debugThrow(); state.error("assertion '%1%' failed", out.str()).atPos(pos).withFrame(env, *this).debugThrow<AssertionError>();
} }
body->eval(state, env, v); body->eval(state, env, v);
} }
@ -1926,14 +1915,14 @@ void ExprConcatStrings::eval(EvalState & state, Env & env, Value & v)
nf = n; nf = n;
nf += vTmp.fpoint; nf += vTmp.fpoint;
} else } else
state.error<EvalError>("cannot add %1% to an integer", showType(vTmp)).atPos(i_pos).withFrame(env, *this).debugThrow(); state.error("cannot add %1% to an integer", showType(vTmp)).atPos(i_pos).withFrame(env, *this).debugThrow<EvalError>();
} else if (firstType == nFloat) { } else if (firstType == nFloat) {
if (vTmp.type() == nInt) { if (vTmp.type() == nInt) {
nf += vTmp.integer; nf += vTmp.integer;
} else if (vTmp.type() == nFloat) { } else if (vTmp.type() == nFloat) {
nf += vTmp.fpoint; nf += vTmp.fpoint;
} else } else
state.error<EvalError>("cannot add %1% to a float", showType(vTmp)).atPos(i_pos).withFrame(env, *this).debugThrow(); state.error("cannot add %1% to a float", showType(vTmp)).atPos(i_pos).withFrame(env, *this).debugThrow<EvalError>();
} else { } else {
if (s.empty()) s.reserve(es->size()); if (s.empty()) s.reserve(es->size());
/* skip canonization of first path, which would only be not /* skip canonization of first path, which would only be not
@ -1953,7 +1942,7 @@ void ExprConcatStrings::eval(EvalState & state, Env & env, Value & v)
v.mkFloat(nf); v.mkFloat(nf);
else if (firstType == nPath) { else if (firstType == nPath) {
if (!context.empty()) if (!context.empty())
state.error<EvalError>("a string that refers to a store path cannot be appended to a path").atPos(pos).withFrame(env, *this).debugThrow(); state.error("a string that refers to a store path cannot be appended to a path").atPos(pos).withFrame(env, *this).debugThrow<EvalError>();
v.mkPath(canonPath(str())); v.mkPath(canonPath(str()));
} else } else
v.mkStringMove(c_str(), context); v.mkStringMove(c_str(), context);
@ -2008,7 +1997,7 @@ NixInt EvalState::forceInt(Value & v, const PosIdx pos, std::string_view errorCt
try { try {
forceValue(v, pos); forceValue(v, pos);
if (v.type() != nInt) if (v.type() != nInt)
error<TypeError>("value is %1% while an integer was expected", showType(v)).debugThrow(); error("value is %1% while an integer was expected", showType(v)).debugThrow<TypeError>();
return v.integer; return v.integer;
} catch (Error & e) { } catch (Error & e) {
e.addTrace(positions[pos], errorCtx); e.addTrace(positions[pos], errorCtx);
@ -2024,7 +2013,7 @@ NixFloat EvalState::forceFloat(Value & v, const PosIdx pos, std::string_view err
if (v.type() == nInt) if (v.type() == nInt)
return v.integer; return v.integer;
else if (v.type() != nFloat) else if (v.type() != nFloat)
error<TypeError>("value is %1% while a float was expected", showType(v)).debugThrow(); error("value is %1% while a float was expected", showType(v)).debugThrow<TypeError>();
return v.fpoint; return v.fpoint;
} catch (Error & e) { } catch (Error & e) {
e.addTrace(positions[pos], errorCtx); e.addTrace(positions[pos], errorCtx);
@ -2038,7 +2027,7 @@ bool EvalState::forceBool(Value & v, const PosIdx pos, std::string_view errorCtx
try { try {
forceValue(v, pos); forceValue(v, pos);
if (v.type() != nBool) if (v.type() != nBool)
error<TypeError>("value is %1% while a Boolean was expected", showType(v)).debugThrow(); error("value is %1% while a Boolean was expected", showType(v)).debugThrow<TypeError>();
return v.boolean; return v.boolean;
} catch (Error & e) { } catch (Error & e) {
e.addTrace(positions[pos], errorCtx); e.addTrace(positions[pos], errorCtx);
@ -2058,7 +2047,7 @@ void EvalState::forceFunction(Value & v, const PosIdx pos, std::string_view erro
try { try {
forceValue(v, pos); forceValue(v, pos);
if (v.type() != nFunction && !isFunctor(v)) if (v.type() != nFunction && !isFunctor(v))
error<TypeError>("value is %1% while a function was expected", showType(v)).debugThrow(); error("value is %1% while a function was expected", showType(v)).debugThrow<TypeError>();
} catch (Error & e) { } catch (Error & e) {
e.addTrace(positions[pos], errorCtx); e.addTrace(positions[pos], errorCtx);
throw; throw;
@ -2071,7 +2060,7 @@ std::string_view EvalState::forceString(Value & v, const PosIdx pos, std::string
try { try {
forceValue(v, pos); forceValue(v, pos);
if (v.type() != nString) if (v.type() != nString)
error<TypeError>("value is %1% while a string was expected", showType(v)).debugThrow(); error("value is %1% while a string was expected", showType(v)).debugThrow<TypeError>();
return v.string.s; return v.string.s;
} catch (Error & e) { } catch (Error & e) {
e.addTrace(positions[pos], errorCtx); e.addTrace(positions[pos], errorCtx);
@ -2132,7 +2121,7 @@ std::string_view EvalState::forceStringNoCtx(Value & v, const PosIdx pos, std::s
{ {
auto s = forceString(v, pos, errorCtx); auto s = forceString(v, pos, errorCtx);
if (v.string.context) { if (v.string.context) {
error<EvalError>("the string '%1%' is not allowed to refer to a store path (such as '%2%')", v.string.s, v.string.context[0]).withTrace(pos, errorCtx).debugThrow(); error("the string '%1%' is not allowed to refer to a store path (such as '%2%')", v.string.s, v.string.context[0]).withTrace(pos, errorCtx).debugThrow<EvalError>();
} }
return s; return s;
} }
@ -2188,7 +2177,7 @@ BackedStringView EvalState::coerceToString(const PosIdx pos, Value & v, PathSet
return std::move(*maybeString); return std::move(*maybeString);
auto i = v.attrs->find(sOutPath); auto i = v.attrs->find(sOutPath);
if (i == v.attrs->end()) if (i == v.attrs->end())
error<TypeError>("cannot coerce a set to a string", showType(v)).withTrace(pos, errorCtx).debugThrow(); error("cannot coerce a set to a string", showType(v)).withTrace(pos, errorCtx).debugThrow<TypeError>();
return coerceToString(pos, *i->value, context, coerceMore, copyToStore, canonicalizePath, errorCtx); return coerceToString(pos, *i->value, context, coerceMore, copyToStore, canonicalizePath, errorCtx);
} }
@ -2223,14 +2212,14 @@ BackedStringView EvalState::coerceToString(const PosIdx pos, Value & v, PathSet
} }
} }
error<TypeError>("cannot coerce %1% to a string", showType(v)).withTrace(pos, errorCtx).debugThrow(); error("cannot coerce %1% to a string", showType(v)).withTrace(pos, errorCtx).debugThrow<TypeError>();
} }
std::string EvalState::copyPathToStore(PathSet & context, const Path & path) std::string EvalState::copyPathToStore(PathSet & context, const Path & path)
{ {
if (nix::isDerivation(path)) if (nix::isDerivation(path))
error<EvalError>("file names are not allowed to end in '%1%'", drvExtension).debugThrow(); error("file names are not allowed to end in '%1%'", drvExtension).debugThrow<EvalError>();
Path dstPath; Path dstPath;
auto i = srcToStore.find(path); auto i = srcToStore.find(path);
@ -2255,7 +2244,7 @@ Path EvalState::coerceToPath(const PosIdx pos, Value & v, PathSet & context, std
{ {
auto path = coerceToString(pos, v, context, false, false, true, errorCtx).toOwned(); auto path = coerceToString(pos, v, context, false, false, true, errorCtx).toOwned();
if (path == "" || path[0] != '/') if (path == "" || path[0] != '/')
error<EvalError>("string '%1%' doesn't represent an absolute path", path).withTrace(pos, errorCtx).debugThrow(); error("string '%1%' doesn't represent an absolute path", path).withTrace(pos, errorCtx).debugThrow<EvalError>();
return path; return path;
} }
@ -2265,7 +2254,7 @@ StorePath EvalState::coerceToStorePath(const PosIdx pos, Value & v, PathSet & co
auto path = coerceToString(pos, v, context, false, false, true, errorCtx).toOwned(); auto path = coerceToString(pos, v, context, false, false, true, errorCtx).toOwned();
if (auto storePath = store->maybeParseStorePath(path)) if (auto storePath = store->maybeParseStorePath(path))
return *storePath; return *storePath;
error<EvalError>("path '%1%' is not in the Nix store", path).withTrace(pos, errorCtx).debugThrow(); error("path '%1%' is not in the Nix store", path).withTrace(pos, errorCtx).debugThrow<EvalError>();
} }
@ -2342,7 +2331,7 @@ bool EvalState::eqValues(Value & v1, Value & v2, const PosIdx pos, std::string_v
return v1.fpoint == v2.fpoint; return v1.fpoint == v2.fpoint;
default: default:
error<EvalError>("cannot compare %1% with %2%", showType(v1), showType(v2)).withTrace(pos, errorCtx).debugThrow(); error("cannot compare %1% with %2%", showType(v1), showType(v2)).withTrace(pos, errorCtx).debugThrow<EvalError>();
} }
} }

63
src/libexpr/eval.hh
View file

@ -87,48 +87,40 @@ struct DebugTrace {
void debugError(Error * e, Env & env, Expr & expr); void debugError(Error * e, Env & env, Expr & expr);
template<class ErrorType>
class ErrorBuilder class ErrorBuilder
{ {
private:
EvalState & state; EvalState & state;
ErrorInfo info; ErrorInfo info;
ErrorBuilder(EvalState & s, ErrorInfo && i): state(s), info(i) { }
public: public:
[[gnu::noinline]]
ErrorBuilder(EvalState & s);
[[gnu::noinline]]
ErrorBuilder<ErrorType> & atPos(PosIdx pos);
template<typename... Args> template<typename... Args>
[[gnu::noinline]] [[nodiscard, gnu::noinline]]
ErrorBuilder<ErrorType> & msg(const std::string & fs, const Args & ... args) static ErrorBuilder * create(EvalState & s, const Args & ... args)
{ {
hintformat f(fs); return new ErrorBuilder(s, ErrorInfo { .msg = hintfmt(args...) });
formatHelper(f, args...);
info.msg = f;
return *this;
} }
[[gnu::noinline]] [[nodiscard, gnu::noinline]]
ErrorBuilder<ErrorType> & withTrace(PosIdx pos, const std::string_view text); ErrorBuilder & atPos(PosIdx pos);
[[gnu::noinline]] [[nodiscard, gnu::noinline]]
ErrorBuilder<ErrorType> & withFrameTrace(PosIdx pos, const std::string_view text); ErrorBuilder & withTrace(PosIdx pos, const std::string_view text);
[[gnu::noinline]] [[nodiscard, gnu::noinline]]
ErrorBuilder<ErrorType> & suggestions(Suggestions & s); ErrorBuilder & withFrameTrace(PosIdx pos, const std::string_view text);
[[gnu::noinline]] [[nodiscard, gnu::noinline]]
ErrorBuilder<ErrorType> & withFrame(const Env & e, const Expr & ex); ErrorBuilder & withSuggestions(Suggestions & s);
[[nodiscard, gnu::noinline]]
ErrorBuilder & withFrame(const Env & e, const Expr & ex);
template<class ErrorType>
[[gnu::noinline, gnu::noreturn]] [[gnu::noinline, gnu::noreturn]]
void ErrorBuilder<ErrorType>::debugThrow() { void debugThrow();
// NOTE: We always use the -LastTrace version as we push the new trace in withFrame()
state.debugThrowLastTrace(ErrorType(info));
}
}; };
@ -212,10 +204,12 @@ public:
throw std::move(error); throw std::move(error);
} }
template<class E, typename... Args> ErrorBuilder * errorBuilder;
ErrorBuilder<E> & error(const std::string & fs, const Args & ... args) {
ErrorBuilder<E> * errorBuilder = new ErrorBuilder<E>(*this); template<typename... Args>
errorBuilder->msg(fs, args ...); [[nodiscard, gnu::noinline]]
ErrorBuilder & error(const Args & ... args) {
errorBuilder = ErrorBuilder::create(*this, args...);
return *errorBuilder; return *errorBuilder;
} }
@ -648,6 +642,13 @@ extern EvalSettings evalSettings;
static const std::string corepkgsPrefix{"/__corepkgs__/"}; static const std::string corepkgsPrefix{"/__corepkgs__/"};
template<class ErrorType>
void ErrorBuilder::debugThrow()
{
// NOTE: We always use the -LastTrace version as we push the new trace in withFrame()
state.debugThrowLastTrace(ErrorType(info));
}
} }
#include "eval-inline.hh" #include "eval-inline.hh"

16
src/libexpr/primops.cc
View file

@ -560,10 +560,7 @@ struct CompareValues
if (v1->type() == nInt && v2->type() == nFloat) if (v1->type() == nInt && v2->type() == nFloat)
return v1->integer < v2->fpoint; return v1->integer < v2->fpoint;
if (v1->type() != v2->type()) if (v1->type() != v2->type())
state.debugThrowLastTrace(EvalError({ state.error("cannot compare %s with %s", showType(*v1), showType(*v2)).debugThrow<EvalError>();
.msg = hintfmt("%scannot compare %s with %s", errorCtx, showType(*v1), showType(*v2)),
.errPos = std::nullopt,
}));
switch (v1->type()) { switch (v1->type()) {
case nInt: case nInt:
return v1->integer < v2->integer; return v1->integer < v2->integer;
@ -581,14 +578,11 @@ struct CompareValues
} else if (i == v1->listSize()) { } else if (i == v1->listSize()) {
return true; return true;
} else if (!state.eqValues(*v1->listElems()[i], *v2->listElems()[i], pos, errorCtx)) { } else if (!state.eqValues(*v1->listElems()[i], *v2->listElems()[i], pos, errorCtx)) {
return (*this)(v1->listElems()[i], v2->listElems()[i], "while comparing two lists"); return (*this)(v1->listElems()[i], v2->listElems()[i], "while comparing two list elements");
} }
} }
default: default:
state.debugThrowLastTrace(EvalError({ state.error("cannot compare %s with %s; values of that type are incomparable", showType(*v1), showType(*v2)).debugThrow<EvalError>();
.msg = hintfmt("%scannot compare %s with %s; values of that type are incomparable", errorCtx, showType(*v1), showType(*v2)),
.errPos = std::nullopt,
}));
} }
} catch (Error & e) { } catch (Error & e) {
e.addTrace(std::nullopt, errorCtx); e.addTrace(std::nullopt, errorCtx);
@ -614,7 +608,7 @@ static Bindings::iterator getAttr(
Bindings::iterator value = attrSet->find(attrSym); Bindings::iterator value = attrSet->find(attrSym);
if (value == attrSet->end()) { if (value == attrSet->end()) {
throw TypeError({ throw TypeError({
.msg = hintfmt("attribute '%s' missing %s", state.symbols[attrSym], errorCtx), .msg = hintfmt("attribute '%s' missing %s", state.symbols[attrSym], normaltxt(errorCtx)),
.errPos = state.positions[attrSet->pos], .errPos = state.positions[attrSet->pos],
}); });
// TODO XXX // TODO XXX
@ -628,7 +622,7 @@ static Bindings::iterator getAttr(
static void prim_genericClosure(EvalState & state, const PosIdx pos, Value * * args, Value & v) static void prim_genericClosure(EvalState & state, const PosIdx pos, Value * * args, Value & v)
{ {
state.forceAttrs(*args[0], noPos, "while evaluating the first argument pased to builtins.genericClosure"); state.forceAttrs(*args[0], noPos, "while evaluating the first argument passed to builtins.genericClosure");
/* Get the start set. */ /* Get the start set. */
Bindings::iterator startSet = getAttr(state, state.sStartSet, args[0]->attrs, "in the attrset passed as argument to builtins.genericClosure"); Bindings::iterator startSet = getAttr(state, state.sStartSet, args[0]->attrs, "in the attrset passed as argument to builtins.genericClosure");

96
src/libexpr/tests/error_traces.cc Normal file
View file

@ -0,0 +1,96 @@
#include <gmock/gmock.h>
#include <gtest/gtest.h>
#include "libexprtests.hh"
namespace nix {
using namespace testing;
// Testing eval of PrimOp's
class ErrorTraceTest : public LibExprTest { };
#define ASSERT_TRACE1(args, type, message) \
ASSERT_THROW( \
try { \
eval("builtins." args); \
} catch (BaseError & e) { \
ASSERT_EQ(PrintToString(e.info().msg), \
PrintToString(message)); \
auto trace = e.info().traces.rbegin(); \
ASSERT_EQ(PrintToString(trace->hint), \
PrintToString(hintfmt("while calling the '%s' builtin", "genericClosure"))); \
throw; \
} \
, type \
)
#define ASSERT_TRACE2(args, type, message, context) \
ASSERT_THROW( \
try { \
eval("builtins." args); \
} catch (BaseError & e) { \
ASSERT_EQ(PrintToString(e.info().msg), \
PrintToString(message)); \
auto trace = e.info().traces.rbegin(); \
ASSERT_EQ(PrintToString(trace->hint), \
PrintToString(context)); \
++trace; \
ASSERT_EQ(PrintToString(trace->hint), \
PrintToString(hintfmt("while calling the '%s' builtin", "genericClosure"))); \
throw; \
} \
, type \
)
//TEST_F(ErrorTraceTest, genericClosure) {
//ASSERT_THROW(
//try {
//eval("builtins.genericClosure 1 1");
//} catch (BaseError & e) {
//ASSERT_EQ(PrintToString(e.info().msg), PrintToString(hintfmt("value is %s while a set was expected", "an integer")));
//throw;
//}, TypeError);
//}
TEST_F(ErrorTraceTest, genericClosure) { \
ASSERT_TRACE2("genericClosure 1",
TypeError,
hintfmt("value is %s while a set was expected", "an integer"),
hintfmt("while evaluating the first argument passed to builtins.genericClosure"));
ASSERT_TRACE1("genericClosure {}",
TypeError,
hintfmt("attribute '%s' missing %s", "startSet", normaltxt("in the attrset passed as argument to builtins.genericClosure")));
ASSERT_TRACE2("genericClosure { startSet = 1; }",
TypeError,
hintfmt("value is %s while a list was expected", "an integer"),
hintfmt("while evaluating the 'startSet' attribute passed as argument to builtins.genericClosure"));
// Okay: "genericClosure { startSet = []; }"
ASSERT_TRACE2("genericClosure { startSet = [{ key = 1;}]; operator = true; }",
TypeError,
hintfmt("value is %s while a function was expected", "a Boolean"),
hintfmt("while evaluating the 'operator' attribute passed as argument to builtins.genericClosure"));
ASSERT_TRACE2("genericClosure { startSet = [{ key = 1;}]; operator = item: true; }",
TypeError,
hintfmt("value is %s while a list was expected", "a Boolean"),
hintfmt("while evaluating the return value of the `operator` passed to builtins.genericClosure")); // TODO: inconsistent naming
ASSERT_TRACE2("genericClosure { startSet = [{ key = 1;}]; operator = item: [ true ]; }",
TypeError,
hintfmt("value is %s while a set was expected", "a Boolean"),
hintfmt("while evaluating one of the elements generated by (or initially passed to) builtins.genericClosure"));
ASSERT_TRACE1("genericClosure { startSet = [{ key = 1;}]; operator = item: [ {} ]; }",
TypeError,
hintfmt("attribute '%s' missing %s", "key", normaltxt("in one of the attrsets generated by (or initially passed to) builtins.genericClosure")));
ASSERT_TRACE2("genericClosure { startSet = [{ key = 1;}]; operator = item: [{ key = ''a''; }]; }",
EvalError,
hintfmt("cannot compare %s with %s", "a string", "an integer"),
hintfmt("while comparing the `key` attributes of two genericClosure elements"));
}
} /* namespace nix */

6
src/libexpr/tests/primops.cc
View file

@ -836,4 +836,10 @@ namespace nix {
for (const auto [n, elem] : enumerate(v.listItems())) for (const auto [n, elem] : enumerate(v.listItems()))
ASSERT_THAT(*elem, IsStringEq(expected[n])); ASSERT_THAT(*elem, IsStringEq(expected[n]));
} }
TEST_F(PrimOpTest, genericClosure_not_strict) {
// Operator should not be used when startSet is empty
auto v = eval("builtins.genericClosure { startSet = []; }");
ASSERT_THAT(v, IsListOfSize(0));
}
} /* namespace nix */ } /* namespace nix */

2
src/libutil/error.hh
View file

@ -192,6 +192,8 @@ public:
void addTrace(std::optional<ErrPos> e, hintformat hint, bool frame = false); void addTrace(std::optional<ErrPos> e, hintformat hint, bool frame = false);
bool hasTrace() const { return !err.traces.empty(); } bool hasTrace() const { return !err.traces.empty(); }
const ErrorInfo & info() { return err; };
}; };
#define MakeError(newClass, superClass) \ #define MakeError(newClass, superClass) \