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environment.cc
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#include "environment.h"
#include "common/formatting.h"
#include "common/sort.h"
#include "common/typecase.h"
#include "core/GlobalState.h"
#include "core/TypeConstraint.h"
#include "core/TypeErrorDiagnostics.h"
#include <algorithm> // find, remove_if
template struct std::pair<sorbet::core::LocalVariable, std::shared_ptr<sorbet::core::Type>>;
using namespace std;
namespace sorbet::infer {
namespace {
core::TypePtr dropConstructor(core::Context ctx, core::Loc loc, core::TypePtr tp) {
if (auto *mt = core::cast_type<core::MetaType>(tp)) {
if (!mt->wrapped.isUntyped()) {
if (auto e = ctx.state.beginError(loc, core::errors::Infer::BareTypeUsage)) {
e.setHeader("Unsupported usage of bare type");
}
}
return core::Types::untypedUntracked();
}
return tp;
}
bool typeTestReferencesVar(const InlinedVector<std::pair<cfg::LocalRef, core::TypePtr>, 1> &typeTest,
cfg::LocalRef var) {
return absl::c_any_of(typeTest, [var](auto &test) { return test.first == var; });
}
} // namespace
void TypeTestReverseIndex::addToIndex(cfg::LocalRef from, cfg::LocalRef to) {
auto &list = index[from];
// Maintain invariant: lists are sorted sets (no duplicate entries)
// lower_bound returns the first location that is >= to's ID, which is where `to` should be inserted if *it != to
// (uses binary search, O(log n))
auto it = absl::c_lower_bound(list, to, [](const auto &a, const auto &b) -> bool { return a.id() < b.id(); });
if (it == list.end() || *it != to) {
list.insert(it, to);
}
}
const InlinedVector<cfg::LocalRef, 1> &TypeTestReverseIndex::get(cfg::LocalRef from) const {
auto it = index.find(from);
if (it == index.end()) {
return empty;
}
return it->second;
}
void TypeTestReverseIndex::replace(cfg::LocalRef from, InlinedVector<cfg::LocalRef, 1> &&list) {
index[from] = std::move(list);
}
void TypeTestReverseIndex::cloneFrom(const TypeTestReverseIndex &index) {
this->index = index.index;
}
const InlinedVector<cfg::LocalRef, 1> TypeTestReverseIndex::empty;
/**
* Encode things that we know hold and don't hold.
*/
struct KnowledgeFact {
bool isDead = false;
/* the following type tests are known to be true */
InlinedVector<std::pair<cfg::LocalRef, core::TypePtr>, 1> yesTypeTests;
/* the following type tests are known to be false */
InlinedVector<std::pair<cfg::LocalRef, core::TypePtr>, 1> noTypeTests;
/* this is a "merge" of two knowledges - computes a "lub" of knowledges */
void min(core::Context ctx, const KnowledgeFact &other);
void sanityCheck() const;
std::string toString(const core::GlobalState &gs, const cfg::CFG &cfg) const;
};
KnowledgeFilter::KnowledgeFilter(core::Context ctx, unique_ptr<cfg::CFG> &cfg) {
used_vars.resize(cfg->numLocalVariables());
for (auto &bb : cfg->basicBlocks) {
ENFORCE(bb->bexit.cond.variable.exists());
if (bb->bexit.cond.variable != cfg::LocalRef::unconditional() &&
bb->bexit.cond.variable != cfg::LocalRef::blockCall()) {
used_vars[bb->bexit.cond.variable.id()] = true;
}
}
bool changed = true;
while (changed) {
changed = false;
for (auto &bb : cfg->forwardsTopoSort) {
for (auto &bind : bb->exprs) {
if (auto *id = cfg::cast_instruction<cfg::Ident>(bind.value)) {
if (isNeeded(bind.bind.variable) && !isNeeded(id->what)) {
used_vars[id->what.id()] = true;
changed = true;
}
} else if (auto *send = cfg::cast_instruction<cfg::Send>(bind.value)) {
if (send->fun == core::Names::bang()) {
if (send->args.empty()) {
if (isNeeded(bind.bind.variable) && !isNeeded(send->recv.variable)) {
used_vars[send->recv.variable.id()] = true;
changed = true;
}
}
} else if (send->fun == core::Names::eqeq()) {
if (send->args.size() == 1) {
if (isNeeded(send->args[0].variable) && !isNeeded(send->recv.variable)) {
used_vars[send->recv.variable.id()] = true;
changed = true;
} else if (isNeeded(send->recv.variable) && !isNeeded(send->args[0].variable)) {
used_vars[send->args[0].variable.id()] = true;
changed = true;
}
}
}
}
}
}
}
}
bool KnowledgeFilter::isNeeded(cfg::LocalRef var) {
return used_vars[var.id()];
}
KnowledgeRef KnowledgeRef::under(core::Context ctx, const Environment &env, cfg::CFG &inWhat, cfg::BasicBlock *bb,
bool isNeeded) const {
if (knowledge->yesTypeTests.empty() && !isNeeded) {
return *this;
}
KnowledgeRef copy = *this;
if (env.isDead) {
copy.markDead();
return copy;
}
bool enteringLoop = (bb->flags & cfg::CFG::LOOP_HEADER) != 0;
for (auto &pair : env.vars()) {
auto local = pair.first;
auto &state = pair.second;
if (enteringLoop && bb->outerLoops <= local.maxLoopWrite(inWhat)) {
continue;
}
auto fnd = absl::c_find_if(copy->yesTypeTests, [&](auto const &e) -> bool { return e.first == local; });
if (fnd == copy->yesTypeTests.end()) {
// add info from env to knowledge
ENFORCE(state.typeAndOrigins.type != nullptr);
// This handles code snippets such as
//
// if (...)
// v = true
// s = 1
// else
// v = false
// s = nil
// end
//
// if (v)
// puts(s + 1)
// end
//
// This pattern is relatively rare in user code, but it ends up
// being important inside the desugaring of `||` and `&&` as well as
// in inferring results from a `hard_assert`
//
// Adding this information makes environments much larger than they
// would be otherwise; Many of the performance optimizations in this
// file effectively exist to support this feature.
auto type = state.typeAndOrigins.type;
if (isNeeded && !type.isUntyped() && !core::isa_type<core::MetaType>(type)) {
// Direct mutation of `yesTypeTests` rather than going through `addYesTypeTest`.
// This is fine since `copy` is unmoored from a particular environment.
copy.mutate().yesTypeTests.emplace_back(local, type);
}
} else {
auto &second = fnd->second;
auto &typeAndOrigin = state.typeAndOrigins;
auto combinedType = core::Types::all(ctx, typeAndOrigin.type, second);
if (combinedType.isBottom()) {
copy.markDead();
break;
}
}
}
return copy;
}
void KnowledgeFact::min(core::Context ctx, const KnowledgeFact &other) {
for (auto it = yesTypeTests.begin(); it != yesTypeTests.end(); /* nothing */) {
auto &entry = *it;
cfg::LocalRef local = entry.first;
auto fnd = absl::c_find_if(other.yesTypeTests, [&](auto const &elem) -> bool { return elem.first == local; });
if (fnd == other.yesTypeTests.end()) {
// Note: No need to update Environment::typeTestsWithVar since it is an overapproximation
it = yesTypeTests.erase(it);
} else {
entry.second = core::Types::any(ctx, fnd->second, entry.second);
it++;
}
}
for (auto it = noTypeTests.begin(); it != noTypeTests.end(); /* nothing */) {
auto &entry = *it;
cfg::LocalRef local = entry.first;
auto fnd = absl::c_find_if(other.noTypeTests, [&](auto const &elem) -> bool { return elem.first == local; });
if (fnd == other.noTypeTests.end()) {
// Note: No need to update Environment::typeTestsWithVar since it is an overapproximation
it = noTypeTests.erase(it);
} else {
entry.second = core::Types::all(ctx, fnd->second, entry.second);
it++;
}
}
}
void KnowledgeFact::sanityCheck() const {
if (!debug_mode) {
return;
}
for (auto &a : yesTypeTests) {
ENFORCE(a.second != nullptr);
ENFORCE(!a.second.isUntyped());
}
for (auto &a : noTypeTests) {
ENFORCE(a.second != nullptr);
ENFORCE(!a.second.isUntyped());
}
}
string KnowledgeFact::toString(const core::GlobalState &gs, const cfg::CFG &cfg) const {
vector<string> buf1, buf2;
for (auto &el : yesTypeTests) {
buf1.emplace_back(
fmt::format(" {} to be {}\n", el.first.showRaw(gs, cfg), el.second.toStringWithTabs(gs, 0)));
}
for (auto &el : noTypeTests) {
buf2.emplace_back(
fmt::format(" {} NOT to be {}\n", el.first.showRaw(gs, cfg), el.second.toStringWithTabs(gs, 0)));
}
fast_sort(buf1);
fast_sort(buf2);
return fmt::format("{}{}", fmt::join(buf1, ""), fmt::join(buf2, ""));
}
KnowledgeRef::KnowledgeRef() : knowledge(std::make_shared<KnowledgeFact>()) {}
const KnowledgeFact &KnowledgeRef::operator*() const {
return *knowledge.get();
}
const KnowledgeFact *KnowledgeRef::operator->() const {
return knowledge.get();
}
KnowledgeFact &KnowledgeRef::mutate() {
if (knowledge.use_count() > 1) {
knowledge = make_shared<KnowledgeFact>(*knowledge);
}
ENFORCE(knowledge.use_count() == 1);
return *knowledge.get();
}
void KnowledgeRef::addYesTypeTest(cfg::LocalRef of, TypeTestReverseIndex &index, cfg::LocalRef ref,
core::TypePtr type) {
index.addToIndex(ref, of);
this->mutate().yesTypeTests.emplace_back(ref, move(type));
}
void KnowledgeRef::addNoTypeTest(cfg::LocalRef of, TypeTestReverseIndex &index, cfg::LocalRef ref, core::TypePtr type) {
index.addToIndex(ref, of);
this->mutate().noTypeTests.emplace_back(ref, move(type));
}
void KnowledgeRef::markDead() {
this->mutate().isDead = true;
}
void KnowledgeRef::min(core::Context ctx, const KnowledgeFact &other) {
this->mutate().min(ctx, other);
}
void KnowledgeRef::removeReferencesToVar(cfg::LocalRef var) {
if (typeTestReferencesVar(knowledge->yesTypeTests, var) || typeTestReferencesVar(knowledge->noTypeTests, var)) {
auto &typeTests = this->mutate();
// No requirement to update Environment::typeTestsWithVar, which is an overapproximation.
typeTests.yesTypeTests.erase(remove_if(typeTests.yesTypeTests.begin(), typeTests.yesTypeTests.end(),
[&](auto const &c) -> bool { return c.first == var; }),
typeTests.yesTypeTests.end());
typeTests.noTypeTests.erase(remove_if(typeTests.noTypeTests.begin(), typeTests.noTypeTests.end(),
[&](auto const &c) -> bool { return c.first == var; }),
typeTests.noTypeTests.end());
}
}
string TestedKnowledge::toString(const core::GlobalState &gs, const cfg::CFG &cfg) const {
fmt::memory_buffer buf;
if (!_truthy->noTypeTests.empty() || !_truthy->yesTypeTests.empty()) {
fmt::format_to(std::back_inserter(buf), " Being truthy entails:\n{}", _truthy->toString(gs, cfg));
}
if (!_falsy->noTypeTests.empty() || !_falsy->yesTypeTests.empty()) {
fmt::format_to(std::back_inserter(buf), " Being falsy entails:\n{}", _falsy->toString(gs, cfg));
}
return to_string(buf);
}
void TestedKnowledge::replaceTruthy(cfg::LocalRef of, TypeTestReverseIndex &index, const KnowledgeRef &newTruthy) {
// Note: No need to remove old items from Environment::typeTestsWithVar since it is an overapproximation
for (auto &entry : newTruthy->yesTypeTests) {
index.addToIndex(entry.first, of);
}
for (auto &entry : newTruthy->noTypeTests) {
index.addToIndex(entry.first, of);
}
_truthy = newTruthy;
}
void TestedKnowledge::replaceFalsy(cfg::LocalRef of, TypeTestReverseIndex &index, const KnowledgeRef &newFalsy) {
// Note: No need to remove old items from Environment::typeTestsWithVar since it is an overapproximation
for (auto &entry : newFalsy->yesTypeTests) {
index.addToIndex(entry.first, of);
}
for (auto &entry : newFalsy->noTypeTests) {
index.addToIndex(entry.first, of);
}
_falsy = newFalsy;
}
void TestedKnowledge::replace(cfg::LocalRef of, TypeTestReverseIndex &index, const TestedKnowledge &knowledge) {
this->seenTruthyOption = knowledge.seenTruthyOption;
this->seenFalsyOption = knowledge.seenFalsyOption;
replaceFalsy(of, index, knowledge.falsy());
replaceTruthy(of, index, knowledge.truthy());
}
void TestedKnowledge::removeReferencesToVar(cfg::LocalRef var) {
this->_truthy.removeReferencesToVar(var);
this->_falsy.removeReferencesToVar(var);
}
void TestedKnowledge::emitKnowledgeSizeMetric() const {
histogramInc("infer.knowledge.truthy.yes.size", _truthy->yesTypeTests.size());
histogramInc("infer.knowledge.truthy.no.size", _truthy->noTypeTests.size());
histogramInc("infer.knowledge.falsy.yes.size", _falsy->yesTypeTests.size());
histogramInc("infer.knowledge.falsy.no.size", _falsy->noTypeTests.size());
}
void TestedKnowledge::sanityCheck() const {
if (!debug_mode) {
return;
}
_truthy->sanityCheck();
_falsy->sanityCheck();
ENFORCE(TestedKnowledge::empty._falsy->yesTypeTests.empty());
ENFORCE(TestedKnowledge::empty._falsy->noTypeTests.empty());
ENFORCE(TestedKnowledge::empty._truthy->noTypeTests.empty());
ENFORCE(TestedKnowledge::empty._truthy->yesTypeTests.empty());
}
string Environment::toString(const core::GlobalState &gs, const cfg::CFG &cfg) const {
fmt::memory_buffer buf;
if (isDead) {
fmt::format_to(std::back_inserter(buf), "dead={:d}\n", isDead);
}
vector<pair<cfg::LocalRef, VariableState>> sorted;
for (const auto &pair : _vars) {
sorted.emplace_back(pair);
}
fast_sort(sorted, [&cfg](const auto &lhs, const auto &rhs) -> bool {
return lhs.first.data(cfg)._name.rawId() < rhs.first.data(cfg)._name.rawId() ||
(lhs.first.data(cfg)._name.rawId() == rhs.first.data(cfg)._name.rawId() &&
lhs.first.data(cfg).unique < rhs.first.data(cfg).unique);
});
for (const auto &pair : sorted) {
auto var = pair.first;
auto &state = pair.second;
if (var.data(cfg)._name == core::Names::debugEnvironmentTemp()) {
continue;
}
fmt::format_to(std::back_inserter(buf), "{}: {}{}\n{}\n", var.showRaw(gs, cfg),
state.typeAndOrigins.type.toStringWithTabs(gs, 0), state.knownTruthy ? " (and truthy)\n" : "",
state.knowledge.toString(gs, cfg));
}
return to_string(buf);
}
bool Environment::hasType(core::Context ctx, cfg::LocalRef symbol) const {
auto fnd = _vars.find(symbol);
if (fnd == _vars.end()) {
return false;
}
// We don't distinguish between nullptr and "not set"
return fnd->second.typeAndOrigins.type != nullptr;
}
const core::TypeAndOrigins &Environment::getTypeAndOrigin(core::Context ctx, cfg::LocalRef symbol) const {
auto fnd = _vars.find(symbol);
if (fnd == _vars.end()) {
return uninitialized;
}
ENFORCE(fnd->second.typeAndOrigins.type != nullptr);
return fnd->second.typeAndOrigins;
}
const core::TypeAndOrigins &Environment::getAndFillTypeAndOrigin(core::Context ctx,
cfg::VariableUseSite &symbol) const {
const auto &ret = getTypeAndOrigin(ctx, symbol.variable);
symbol.type = ret.type;
return ret;
}
bool Environment::getKnownTruthy(cfg::LocalRef var) const {
auto fnd = _vars.find(var);
if (fnd == _vars.end()) {
return false;
}
return fnd->second.knownTruthy;
}
void Environment::propagateKnowledge(core::Context ctx, cfg::LocalRef to, cfg::LocalRef from,
KnowledgeFilter &knowledgeFilter) {
if (knowledgeFilter.isNeeded(to) && knowledgeFilter.isNeeded(from)) {
auto &fromState = _vars[from];
auto &toState = _vars[to];
toState.knownTruthy = fromState.knownTruthy;
auto &toKnowledge = toState.knowledge;
auto &fromKnowledge = fromState.knowledge;
if (fromState.typeAndOrigins.type == nullptr) {
fromState.typeAndOrigins.type = core::Types::nilClass();
}
if (toState.typeAndOrigins.type == nullptr) {
toState.typeAndOrigins.type = core::Types::nilClass();
}
// Copy properties from fromKnowledge to toKnowledge
toKnowledge.replace(to, typeTestsWithVar, fromKnowledge);
toKnowledge.truthy().addNoTypeTest(to, typeTestsWithVar, from, core::Types::falsyTypes());
toKnowledge.falsy().addYesTypeTest(to, typeTestsWithVar, from, core::Types::falsyTypes());
fromKnowledge.truthy().addNoTypeTest(from, typeTestsWithVar, to, core::Types::falsyTypes());
fromKnowledge.falsy().addYesTypeTest(from, typeTestsWithVar, to, core::Types::falsyTypes());
fromKnowledge.sanityCheck();
toKnowledge.sanityCheck();
}
}
void Environment::clearKnowledge(core::Context ctx, cfg::LocalRef reassigned, KnowledgeFilter &knowledgeFilter) {
auto &typesWithReassigned = typeTestsWithVar.get(reassigned);
if (!typesWithReassigned.empty()) {
InlinedVector<cfg::LocalRef, 1> replacement;
for (auto &var : typesWithReassigned) {
if (knowledgeFilter.isNeeded(var)) {
auto &k = getKnowledge(var);
k.removeReferencesToVar(reassigned);
k.sanityCheck();
} else {
replacement.emplace_back(var);
}
}
typeTestsWithVar.replace(reassigned, std::move(replacement));
}
auto fnd = _vars.find(reassigned);
ENFORCE(fnd != _vars.end());
fnd->second.knownTruthy = false;
}
namespace {
// A singleton is a class which is inhabited by a single value.
//
// If a variable != a value whose type is a singleton, then that variable's type must not be that value's type.
//
// This is not the case for most other equality tests. e.g., x != 0 does not imply ¬ x : Integer.
//
// This powers (among other things) exhaustiveness checking for T::Enum.
bool isSingleton(core::Context ctx, core::ClassOrModuleRef sym) {
// Singletons that are built into the Ruby VM
if (sym == core::Symbols::NilClass() || sym == core::Symbols::FalseClass() || sym == core::Symbols::TrueClass()) {
return true;
}
// T::Enum values are modeled as singletons of their own fake class.
if (sym.data(ctx)->name.isTEnumName(ctx)) {
return true;
}
// attachedClass on untyped symbol is defined to return itself
if (sym != core::Symbols::untyped() && sym.data(ctx)->attachedClass(ctx).exists() && sym.data(ctx)->flags.isFinal) {
// This is a Ruby singleton class object
return true;
}
// The Ruby stdlib has a Singleton module which lets people invent their own singletons.
return (sym.data(ctx)->derivesFrom(ctx, core::Symbols::Singleton()) && sym.data(ctx)->flags.isFinal);
}
} // namespace
void Environment::updateKnowledge(core::Context ctx, cfg::LocalRef local, core::Loc loc, const cfg::Send *send,
KnowledgeFilter &knowledgeFilter) {
if (send->fun == core::Names::bang()) {
if (!knowledgeFilter.isNeeded(local)) {
return;
}
auto &whoKnows = getKnowledge(local);
auto fnd = _vars.find(send->recv.variable);
if (fnd != _vars.end()) {
whoKnows.replaceTruthy(local, typeTestsWithVar, fnd->second.knowledge.falsy());
whoKnows.replaceFalsy(local, typeTestsWithVar, fnd->second.knowledge.truthy());
fnd->second.knowledge.truthy().addYesTypeTest(fnd->first, typeTestsWithVar, local,
core::Types::falsyTypes());
fnd->second.knowledge.falsy().addNoTypeTest(fnd->first, typeTestsWithVar, local, core::Types::falsyTypes());
}
whoKnows.truthy().addYesTypeTest(local, typeTestsWithVar, send->recv.variable, core::Types::falsyTypes());
whoKnows.falsy().addNoTypeTest(local, typeTestsWithVar, send->recv.variable, core::Types::falsyTypes());
whoKnows.sanityCheck();
} else if (send->fun == core::Names::nil_p()) {
if (!knowledgeFilter.isNeeded(local)) {
return;
}
auto &whoKnows = getKnowledge(local);
whoKnows.truthy().addYesTypeTest(local, typeTestsWithVar, send->recv.variable, core::Types::nilClass());
whoKnows.falsy().addNoTypeTest(local, typeTestsWithVar, send->recv.variable, core::Types::nilClass());
whoKnows.sanityCheck();
} else if (send->fun == core::Names::blank_p()) {
if (!knowledgeFilter.isNeeded(local)) {
return;
}
// Note that this assumes that .blank? is a rails-compatible monkey patch.
// In other cases this flow analysis might make incorrect assumptions.
auto &originalType = send->recv.type;
auto knowledgeTypeWithoutFalsy = core::Types::approximateSubtract(ctx, originalType, core::Types::falsyTypes());
if (!core::Types::equiv(ctx, knowledgeTypeWithoutFalsy, originalType)) {
auto &whoKnows = getKnowledge(local);
whoKnows.falsy().addYesTypeTest(local, typeTestsWithVar, send->recv.variable, knowledgeTypeWithoutFalsy);
whoKnows.sanityCheck();
}
} else if (send->fun == core::Names::present_p()) {
if (!knowledgeFilter.isNeeded(local)) {
return;
}
// Note that this assumes that .present? is a rails-compatible monkey patch.
// In other cases this flow analysis might make incorrect assumptions.
auto &originalType = send->recv.type;
auto knowledgeTypeWithoutFalsy = core::Types::approximateSubtract(ctx, originalType, core::Types::falsyTypes());
if (!core::Types::equiv(ctx, knowledgeTypeWithoutFalsy, originalType)) {
auto &whoKnows = getKnowledge(local);
whoKnows.truthy().addYesTypeTest(local, typeTestsWithVar, send->recv.variable, knowledgeTypeWithoutFalsy);
whoKnows.sanityCheck();
}
}
if (send->args.empty()) {
return;
}
// TODO(jez) We should probably update this to be aware of T::NonForcingConstants.non_forcing_is_a?
if (send->fun == core::Names::kindOf_p() || send->fun == core::Names::isA_p()) {
if (!knowledgeFilter.isNeeded(local)) {
return;
}
auto &whoKnows = getKnowledge(local);
auto &klassType = send->args[0].type;
core::ClassOrModuleRef klass = core::Types::getRepresentedClass(ctx, klassType);
if (klass.exists()) {
auto ty = klass.data(ctx)->externalType();
if (!ty.isUntyped()) {
whoKnows.truthy().addYesTypeTest(local, typeTestsWithVar, send->recv.variable, ty);
whoKnows.falsy().addNoTypeTest(local, typeTestsWithVar, send->recv.variable, ty);
}
whoKnows.sanityCheck();
}
} else if (send->fun == core::Names::eqeq() || send->fun == core::Names::equal_p() ||
send->fun == core::Names::neq()) {
if (!knowledgeFilter.isNeeded(local)) {
return;
}
auto &whoKnows = getKnowledge(local);
const auto &argType = send->args[0].type;
const auto &recvType = send->recv.type;
auto funIsEq = send->fun == core::Names::eqeq() || send->fun == core::Names::equal_p();
auto &truthy = funIsEq ? whoKnows.truthy() : whoKnows.falsy();
auto &falsy = funIsEq ? whoKnows.falsy() : whoKnows.truthy();
ENFORCE(argType != nullptr);
ENFORCE(recvType != nullptr);
if (!argType.isUntyped()) {
truthy.addYesTypeTest(local, typeTestsWithVar, send->recv.variable, argType);
auto argSymbol = core::Symbols::noClassOrModule();
if (core::isa_type<core::ClassType>(argType)) {
auto c = core::cast_type_nonnull<core::ClassType>(argType);
argSymbol = c.symbol;
} else if (core::isa_type<core::AppliedType>(argType)) {
auto a = core::cast_type_nonnull<core::AppliedType>(argType);
argSymbol = a.klass;
}
if (argSymbol.exists() && isSingleton(ctx, argSymbol)) {
falsy.addNoTypeTest(local, typeTestsWithVar, send->recv.variable, argType);
}
}
if (!recvType.isUntyped()) {
truthy.addYesTypeTest(local, typeTestsWithVar, send->args[0].variable, recvType);
core::ClassOrModuleRef recvSymbol = core::Symbols::noClassOrModule();
if (core::isa_type<core::ClassType>(recvType)) {
auto c = core::cast_type_nonnull<core::ClassType>(recvType);
recvSymbol = c.symbol;
} else if (core::isa_type<core::AppliedType>(recvType)) {
auto a = core::cast_type_nonnull<core::AppliedType>(recvType);
recvSymbol = a.klass;
}
if (recvSymbol.exists() && isSingleton(ctx, recvSymbol)) {
falsy.addNoTypeTest(local, typeTestsWithVar, send->args[0].variable, recvType);
}
}
whoKnows.sanityCheck();
} else if (send->fun == core::Names::tripleEq()) {
if (!knowledgeFilter.isNeeded(local)) {
return;
}
auto &whoKnows = getKnowledge(local);
const auto &recvType = send->recv.type;
// `when` against class literal
core::ClassOrModuleRef representedClass = core::Types::getRepresentedClass(ctx, recvType);
if (representedClass.exists()) {
auto representedType = representedClass.data(ctx)->externalType();
if (!representedType.isUntyped()) {
whoKnows.truthy().addYesTypeTest(local, typeTestsWithVar, send->args[0].variable, representedType);
whoKnows.falsy().addNoTypeTest(local, typeTestsWithVar, send->args[0].variable, representedType);
}
}
// `when` against singleton
if (core::isa_type<core::ClassType>(recvType)) {
auto s = core::cast_type_nonnull<core::ClassType>(recvType);
// check if s is a singleton. in this case we can learn that
// a failed comparison means that type test would also fail
if (isSingleton(ctx, s.symbol)) {
whoKnows.truthy().addYesTypeTest(local, typeTestsWithVar, send->args[0].variable, recvType);
whoKnows.falsy().addNoTypeTest(local, typeTestsWithVar, send->args[0].variable, recvType);
}
}
whoKnows.sanityCheck();
} else if (send->fun == core::Names::lessThan() || send->fun == core::Names::leq()) {
const auto &recvKlass = send->recv.type;
const auto &argType = send->args[0].type;
if (core::isa_type<core::ClassType>(argType)) {
auto argClass = core::cast_type_nonnull<core::ClassType>(argType);
if (!recvKlass.derivesFrom(ctx, core::Symbols::Class()) ||
!argClass.symbol.data(ctx)->derivesFrom(ctx, core::Symbols::Class())) {
return;
}
} else if (auto *argClass = core::cast_type<core::AppliedType>(argType)) {
if (!recvKlass.derivesFrom(ctx, core::Symbols::Class()) ||
!argClass->klass.data(ctx)->derivesFrom(ctx, core::Symbols::Class())) {
return;
}
} else {
return;
}
auto &whoKnows = getKnowledge(local);
whoKnows.truthy().addYesTypeTest(local, typeTestsWithVar, send->recv.variable, argType);
if (send->fun == core::Names::leq()) {
// We only know the NoTypeTest for `<=`, not `<`, because `x < A` being false could mean
// that `x == A`, which would mean `x` still has type `T.class_of(A)`.
whoKnows.falsy().addNoTypeTest(local, typeTestsWithVar, send->recv.variable, argType);
}
whoKnows.sanityCheck();
}
}
void Environment::setTypeAndOrigin(cfg::LocalRef symbol, const core::TypeAndOrigins &typeAndOrigins) {
ENFORCE(typeAndOrigins.type != nullptr);
_vars[symbol].typeAndOrigins = typeAndOrigins;
}
const Environment &Environment::withCond(core::Context ctx, const Environment &env, Environment ©, bool isTrue,
const UnorderedMap<cfg::LocalRef, VariableState> &filter) {
ENFORCE(env.bb->bexit.cond.variable.exists());
if (env.bb->bexit.cond.variable == cfg::LocalRef::unconditional() ||
env.bb->bexit.cond.variable == cfg::LocalRef::blockCall()) {
return env;
}
copy.cloneFrom(env);
copy.assumeKnowledge(ctx, isTrue, env.bb->bexit.cond.variable, ctx.locAt(env.bb->bexit.loc), filter);
return copy;
}
void Environment::assumeKnowledge(core::Context ctx, bool isTrue, cfg::LocalRef cond, core::Loc loc,
const UnorderedMap<cfg::LocalRef, VariableState> &filter) {
const auto &thisKnowledge = getKnowledge(cond, false);
thisKnowledge.sanityCheck();
if (!isTrue) {
if (getKnownTruthy(cond)) {
isDead = true;
return;
}
core::TypeAndOrigins tp = getTypeAndOrigin(ctx, cond);
tp.origins.emplace_back(loc);
if (tp.type.isUntyped()) {
tp.type = core::Types::falsyTypes();
} else {
tp.type = core::Types::all(ctx, tp.type, core::Types::falsyTypes());
if (tp.type.isBottom()) {
isDead = true;
return;
}
}
setTypeAndOrigin(cond, tp);
} else {
core::TypeAndOrigins tp = getTypeAndOrigin(ctx, cond);
tp.origins.emplace_back(loc);
tp.type = core::Types::dropSubtypesOf(ctx, core::Types::dropSubtypesOf(ctx, tp.type, core::Symbols::NilClass()),
core::Symbols::FalseClass());
if (tp.type.isBottom()) {
isDead = true;
return;
}
setTypeAndOrigin(cond, tp);
_vars[cond].knownTruthy = true;
}
if (isDead) {
return;
}
auto &knowledgeToChoose = isTrue ? thisKnowledge.truthy() : thisKnowledge.falsy();
auto &yesTests = knowledgeToChoose->yesTypeTests;
auto &noTests = knowledgeToChoose->noTypeTests;
for (auto &typeTested : yesTests) {
if (!filter.contains(typeTested.first)) {
continue;
}
core::TypeAndOrigins tp = getTypeAndOrigin(ctx, typeTested.first);
auto glbbed = core::Types::all(ctx, tp.type, typeTested.second);
if (tp.type != glbbed) {
tp.origins.emplace_back(loc);
tp.type = glbbed;
}
setTypeAndOrigin(typeTested.first, tp);
if (tp.type.isBottom()) {
isDead = true;
return;
}
}
for (auto &typeTested : noTests) {
if (!filter.contains(typeTested.first)) {
continue;
}
core::TypeAndOrigins tp = getTypeAndOrigin(ctx, typeTested.first);
tp.origins.emplace_back(loc);
if (!tp.type.isUntyped()) {
tp.type = core::Types::approximateSubtract(ctx, tp.type, typeTested.second);
setTypeAndOrigin(typeTested.first, tp);
if (tp.type.isBottom()) {
isDead = true;
return;
}
}
}
}
void Environment::mergeWith(core::Context ctx, const Environment &other, cfg::CFG &inWhat, cfg::BasicBlock *bb,
KnowledgeFilter &knowledgeFilter) {
this->isDead |= other.isDead;
for (auto &pair : _vars) {
auto var = pair.first;
const auto &otherTO = other.getTypeAndOrigin(ctx, var);
auto &thisTO = pair.second.typeAndOrigins;
if (thisTO.type != nullptr) {
thisTO.type = core::Types::any(ctx, thisTO.type, otherTO.type);
thisTO.type.sanityCheck(ctx);
for (auto origin : otherTO.origins) {
if (!absl::c_linear_search(thisTO.origins, origin)) {
thisTO.origins.emplace_back(origin);
}
}
pair.second.knownTruthy = pair.second.knownTruthy && other.getKnownTruthy(var);
} else {
thisTO = otherTO;
pair.second.knownTruthy = other.getKnownTruthy(var);
}
if (((bb->flags & cfg::CFG::LOOP_HEADER) != 0) && bb->outerLoops <= var.maxLoopWrite(inWhat)) {
continue;
}
bool canBeFalsy = core::Types::canBeFalsy(ctx, otherTO.type) && !other.getKnownTruthy(var);
bool canBeTruthy = core::Types::canBeTruthy(ctx, otherTO.type);
if (canBeTruthy) {
auto &thisKnowledge = getKnowledge(var);
auto otherTruthy =
other.getKnowledge(var, false).truthy().under(ctx, other, inWhat, bb, knowledgeFilter.isNeeded(var));
if (!otherTruthy->isDead) {
if (!thisKnowledge.seenTruthyOption) {
thisKnowledge.seenTruthyOption = true;
thisKnowledge.replaceTruthy(var, typeTestsWithVar, otherTruthy);
} else {
thisKnowledge.truthy().min(ctx, *otherTruthy);
}
}
}
if (canBeFalsy) {
auto &thisKnowledge = getKnowledge(var);
auto otherFalsy =
other.getKnowledge(var, false).falsy().under(ctx, other, inWhat, bb, knowledgeFilter.isNeeded(var));
if (!otherFalsy->isDead) {
if (!thisKnowledge.seenFalsyOption) {
thisKnowledge.seenFalsyOption = true;
thisKnowledge.replaceFalsy(var, typeTestsWithVar, otherFalsy);
} else {
thisKnowledge.falsy().min(ctx, *otherFalsy);
}
}
}
}
}
void Environment::computePins(core::Context ctx, const vector<Environment> &envs, const cfg::CFG &inWhat,
const cfg::BasicBlock *bb) {
if (bb->backEdges.empty()) {
return;
}
for (auto &pair : _vars) {
auto var = pair.first;
core::TypeAndOrigins tp;
auto bindMinLoops = var.minLoops(inWhat);
if (bb->outerLoops == bindMinLoops || bindMinLoops == var.maxLoopWrite(inWhat)) {
continue;
}
for (cfg::BasicBlock *parent : bb->backEdges) {
auto &other = envs[parent->id];
auto otherPin = other.pinnedTypes.find(var);
if (otherPin != other.pinnedTypes.end()) {
if (tp.type != nullptr) {
tp.type = core::Types::any(ctx, tp.type, otherPin->second.type);
for (auto origin : otherPin->second.origins) {
if (!absl::c_linear_search(tp.origins, origin)) {
tp.origins.emplace_back(origin);
}
}
tp.type.sanityCheck(ctx);
} else {
tp = otherPin->second;
}
}
}
if (tp.type != nullptr) {
pinnedTypes[var] = tp;
}
}
}
void Environment::populateFrom(core::Context ctx, const Environment &other) {
this->isDead = other.isDead;
for (auto &pair : _vars) {
auto var = pair.first;
pair.second.typeAndOrigins = other.getTypeAndOrigin(ctx, var);
pair.second.knowledge.replace(var, typeTestsWithVar, other.getKnowledge(var, false));
pair.second.knownTruthy = other.getKnownTruthy(var);
}
this->pinnedTypes = other.pinnedTypes;
}
core::TypePtr Environment::getReturnType(core::Context ctx, const core::TypePtr &procType) {
if (!procType.derivesFrom(ctx, core::Symbols::Proc())) {
return core::Types::untypedUntracked();
}
auto *applied = core::cast_type<core::AppliedType>(procType);
if (applied == nullptr || applied->targs.empty()) {
return core::Types::untypedUntracked();
}
// Proc types have their return type as the first targ
return applied->targs.front();
}
core::TypePtr flatmapHack(core::Context ctx, const core::TypePtr &receiver, const core::TypePtr &returnType,
core::NameRef fun, const core::Loc &loc) {
if (fun != core::Names::flatMap()) {
return returnType;
}
if (!receiver.derivesFrom(ctx, core::Symbols::Enumerable())) {
return returnType;
}
if (!receiver.isUntyped() && receiver.derivesFrom(ctx, core::Symbols::Enumerator_Lazy())) {
return returnType;
}
int64_t flattenDepth = 1;
auto mapType = core::Types::arrayOf(ctx, returnType);
const core::TypeAndOrigins recvType = {mapType, {loc}};
core::TypeAndOrigins arg{core::make_type<core::LiteralType>((int64_t)flattenDepth), recvType.origins};
InlinedVector<const core::TypeAndOrigins *, 2> args{&arg};
InlinedVector<core::LocOffsets, 2> argLocs{loc.offsets()};
core::CallLocs locs{
ctx.file, loc.offsets(), loc.offsets(), loc.offsets(), argLocs,
};
core::DispatchArgs dispatchArgs{core::Names::flatten(), locs, 1, args, recvType.type, recvType,
recvType.type, nullptr, loc, true, false};
auto dispatched = recvType.type.dispatchCall(ctx, dispatchArgs);
if (dispatched.main.errors.empty()) {
return std::move(dispatched.returnType);
}
return mapType;
}
core::TypePtr Environment::processBinding(core::Context ctx, const cfg::CFG &inWhat, cfg::Binding &bind, int loopCount,
int bindMinLoops, KnowledgeFilter &knowledgeFilter,
core::TypeConstraint &constr, core::TypePtr &methodReturnType) {
try {
core::TypeAndOrigins tp;
bool noLoopChecking = cfg::isa_instruction<cfg::Alias>(bind.value) ||
cfg::isa_instruction<cfg::LoadArg>(bind.value) ||
bind.bind.variable == cfg::LocalRef::selfVariable();
bool checkFullyDefined = true;
const core::lsp::Query &lspQuery = ctx.state.lspQuery;
bool lspQueryMatch = lspQuery.matchesLoc(ctx.locAt(bind.loc));
typecase(
bind.value,
[&](cfg::Send &send) {
// Overwrite lspQueryMatch for send nodes, so that we only produce a result when
// hovering over the method or arguments (not the block)
auto locWithoutBlock = send.locWithoutBlock(bind.loc);
if (lspQueryMatch && locWithoutBlock.exists() && !locWithoutBlock.empty()) {
lspQueryMatch = lspQuery.matchesLoc(ctx.locAt(locWithoutBlock));
}
InlinedVector<const core::TypeAndOrigins *, 2> args;
args.reserve(send.args.size());
for (cfg::VariableUseSite &arg : send.args) {
args.emplace_back(&getAndFillTypeAndOrigin(ctx, arg));
}
const core::TypeAndOrigins &recvType = getAndFillTypeAndOrigin(ctx, send.recv);
if (send.link) {
checkFullyDefined = false;
}
core::CallLocs locs{
ctx.file, bind.loc, send.receiverLoc, send.funLoc, send.argLocs,
};
// This is the main place where we type check a method, so we default by assuming
// that we want to report all errors (supressing nothing).
auto suppressErrors = false;
core::DispatchArgs dispatchArgs{
send.fun, locs, send.numPosArgs, args, recvType.type, recvType, recvType.type,
send.link, ownerLoc, send.isPrivateOk, suppressErrors};
auto dispatched = recvType.type.dispatchCall(ctx, dispatchArgs);
auto it = &dispatched;
auto multipleComponents = it->secondary != nullptr;
while (it != nullptr) {
for (auto &err : it->main.errors) {
ctx.state._error(std::move(err));
}
// Sometimes we hit a method here where the method symbol is Symbols::noSymbol().
//
// The primary cases for that is:
// - When the receiver is untyped
// - When the receiver is a void type
// - Calling super