kill nullability of IC

Summary: kill the nullability of the implicit context. In future, if we ever want a null IC, we will implement a separate object representing null IC Reviewed By: jano Differential Revision: D57465829 fbshipit-source-id: ecaca8bfb83b23b66c68352317e689c4536b8889
facebook · May 19, 2024 · 36b218e · 36b218e
1 parent 749b7f5
commit 36b218e
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Showing 12 changed files with 32 additions and 71 deletions.
diff --git a/hphp/doc/bytecode.specification b/hphp/doc/bytecode.specification
@@ -3206,7 +3206,7 @@ RaiseClassStringConversionNotice [] -> []
   Raises a notice indicating an implicit class to string conversion.
   This notice is emitted at a sampled rate through a runtime option.
 
-SetImplicitContextByValue [C:?Obj] -> [C:?Obj]
+SetImplicitContextByValue [C:Obj] -> [C:Obj]
 
   Sets the implicit context to %1 and returns the previous implicit context.
 

diff --git a/hphp/doc/ir.specification b/hphp/doc/ir.specification
@@ -1366,7 +1366,7 @@ To string conversions:
 
   Load the ArrayData* containing the generics attached to the RFuncData in S0
 
-| LdImplicitContext, D(Obj|InitNull), NA, NF
+| LdImplicitContext, D(Obj), NA, NF
 
   Loads implicit context from RDS.
 
@@ -1801,7 +1801,7 @@ ReqBindJmp and CallFuncEntry.
   Store the TypedValue in S0 into the specified RDS handle. Must store the aux
   bits if `includeAux` is true.
 
-| StImplicitContext, ND, S(Obj|InitNull), NF
+| StImplicitContext, ND, S(Obj), NF
 
   Sets the implicit context to S0.
 

diff --git a/hphp/hhbbc/interp.cpp b/hphp/hhbbc/interp.cpp
@@ -5483,7 +5483,7 @@ void in(ISS& env, const bc::AwaitAll& op) {
 
 void in(ISS& env, const bc::SetImplicitContextByValue&) {
   popC(env);
-  push(env, TOptObj);
+  push(env, TObj);
 }
 
 const StaticString

diff --git a/hphp/runtime/base/execution-context.cpp b/hphp/runtime/base/execution-context.cpp
@@ -1745,6 +1745,7 @@ void ExecutionContext::resumeAsyncFunc(Resumable* resumable,
                                        ObjectData* freeObj,
                                        const TypedValue awaitResult) {
   assertx(regState() == VMRegState::CLEAN);
+  assertx(*ImplicitContext::activeCtx);
   SCOPE_EXIT { assertx(regState() == VMRegState::CLEAN); };
 
   auto fp = resumable->actRec();
@@ -1789,6 +1790,7 @@ void ExecutionContext::resumeAsyncFuncThrow(Resumable* resumable,
   assertx(exception);
   assertx(exception->instanceof(SystemLib::getThrowableClass()));
   assertx(regState() == VMRegState::CLEAN);
+  assertx(*ImplicitContext::activeCtx);
   SCOPE_EXIT { assertx(regState() == VMRegState::CLEAN); };
 
   auto fp = resumable->actRec();

diff --git a/hphp/runtime/ext/asio/ext_async-function-wait-handle.cpp b/hphp/runtime/ext/asio/ext_async-function-wait-handle.cpp
@@ -135,6 +135,7 @@ c_AsyncFunctionWaitHandle::Create(const ActRec* fp,
   waitHandle->m_packedTailFrameIds = -1;
   assertx(!waitHandle->hasTailFrames());
   waitHandle->initialize(child);
+  assertx(*ImplicitContext::activeCtx);
   waitHandle->m_implicitContext = *ImplicitContext::activeCtx;
   return waitHandle;
 }
@@ -194,6 +195,7 @@ void c_AsyncFunctionWaitHandle::await(Offset suspendOffset,
                                       req::ptr<c_WaitableWaitHandle>&& child) {
   // Prepare child for establishing dependency. May throw.
   prepareChild(child.get());
+  assertx(*ImplicitContext::activeCtx);
   this->m_implicitContext = *ImplicitContext::activeCtx;
 
   // Suspend the async function.

diff --git a/hphp/runtime/ext/asio/ext_async-generator-wait-handle.cpp b/hphp/runtime/ext/asio/ext_async-generator-wait-handle.cpp
@@ -69,6 +69,7 @@ c_AsyncGeneratorWaitHandle::Create(const ActRec* fp,
   gen->resumable()->setResumeAddr(resumeAddr, suspendOffset);
   gen->attachWaitHandle(req::ptr<c_AsyncGeneratorWaitHandle>(wh));
 
+  assertx(*ImplicitContext::activeCtx);
   wh.get()->m_implicitContext = *ImplicitContext::activeCtx;
   return wh.detach();
 }

diff --git a/hphp/runtime/ext/asio/ext_waitable-wait-handle.cpp b/hphp/runtime/ext/asio/ext_waitable-wait-handle.cpp
@@ -43,6 +43,7 @@ void c_WaitableWaitHandle::join() {
 
   assertx(!isFinished());
 
+  assertx(*ImplicitContext::activeCtx);
   auto const context = *ImplicitContext::activeCtx;
 
   AsioSession* session = AsioSession::Get();
@@ -61,6 +62,7 @@ void c_WaitableWaitHandle::join() {
   // run queues until we are finished
   session->getCurrentContext()->runUntil(this);
   assertx(isFinished());
+  assertx(context);
   *ImplicitContext::activeCtx = context;
 }
 

diff --git a/hphp/runtime/ext/hh/ext_implicit_context.cpp b/hphp/runtime/ext/hh/ext_implicit_context.cpp
@@ -86,9 +86,11 @@ Object create_new_IC() {
 } // namespace
 
 bool HHVM_FUNCTION(is_inaccessible) {
+  assertx(*ImplicitContext::activeCtx);
   auto const obj = *ImplicitContext::activeCtx;
-  if (!obj) return false;
   auto const context = Native::data<ImplicitContext>(obj);
+  // In future, if we add a nullstate, that will be implemented
+  // using an object to represent the null state
   return context->m_state == ImplicitContext::State::Inaccessible;
 }
 
@@ -100,8 +102,8 @@ Object initInaccessibleConext() {
 };
 
 String HHVM_FUNCTION(get_state_unsafe) {
+  assertx(*ImplicitContext::activeCtx);
   auto const obj = *ImplicitContext::activeCtx;
-  if (!obj) return String{s_ICStateNull.get()};
   auto const context = Native::data<ImplicitContext>(obj);
 
   switch (context->m_state) {
@@ -118,8 +120,8 @@ String HHVM_FUNCTION(get_state_unsafe) {
 }
 
 TypedValue HHVM_FUNCTION(get_implicit_context, StringArg key) {
+  assertx(*ImplicitContext::activeCtx);
   auto const obj = *ImplicitContext::activeCtx;
-  if (!obj) return make_tv<KindOfNull>();
   auto const context = Native::data<ImplicitContext>(obj);
 
   switch (context->m_state) {
@@ -141,9 +143,9 @@ TypedValue HHVM_FUNCTION(get_implicit_context, StringArg key) {
   not_reached();
 }
 
-Variant HHVM_FUNCTION(get_whole_implicit_context) {
+ObjectRet HHVM_FUNCTION(get_whole_implicit_context) {
+  assertx(*ImplicitContext::activeCtx);
   auto const obj = *ImplicitContext::activeCtx;
-  if (!obj) return init_null();
   return Object{obj};
 }
 
@@ -153,6 +155,7 @@ Variant HHVM_FUNCTION(get_whole_implicit_context) {
  * the IC should stay alive due to being stored in s_memokey_to_IC
 */
 int64_t HHVM_FUNCTION(get_implicit_context_memo_key) {
+  assertx(*ImplicitContext::activeCtx);
   auto const obj = *ImplicitContext::activeCtx;
   return reinterpret_cast<int64_t>(obj);
 }
@@ -162,8 +165,8 @@ int64_t HHVM_FUNCTION(get_implicit_context_memo_key) {
 * Only to be used for testing
 */
 Array HHVM_FUNCTION(get_implicit_context_debug_info) {
+  assertx(*ImplicitContext::activeCtx);
   auto const obj = *ImplicitContext::activeCtx;
-  if (!obj) return Array{};
   auto const context = Native::data<ImplicitContext>(obj);
 
   if (context->m_state != ImplicitContext::State::Value) {
@@ -195,6 +198,7 @@ Object HHVM_FUNCTION(create_implicit_context, StringArg keyarg,
     throw_implicit_context_exception(
       "Implicit context keys cannot be empty or start with _");
   }
+  assertx(*ImplicitContext::activeCtx);
   auto const prev = *ImplicitContext::activeCtx;
 
   // Compute memory key first

diff --git a/hphp/runtime/ext/hh/ext_implicit_context.php b/hphp/runtime/ext/hh/ext_implicit_context.php
@@ -93,7 +93,7 @@ final class ImplicitContextData {}
 function get_implicit_context(string $key)[zoned]: mixed;
 
 <<__Native>>
-function get_whole_implicit_context()[zoned]: ?ImplicitContextData;
+function get_whole_implicit_context()[zoned]: ImplicitContextData;
 
 /**
  * Creates implicit context $context keyed by $key.

diff --git a/hphp/runtime/vm/bytecode.cpp b/hphp/runtime/vm/bytecode.cpp
@@ -5187,26 +5187,12 @@ OPTBLD_INLINE void iopWHResult() {
 
 OPTBLD_INLINE void iopSetImplicitContextByValue() {
   auto const tv = *vmStack().topC();
-  auto const obj = [&]() -> ObjectData* {
-    if (tvIsNull(tv)) return nullptr;
-    if (UNLIKELY(!tvIsObject(tv))) {
-      SystemLib::throwInvalidArgumentExceptionObject(
-        "Invalid input to SetImplicitContextByValue");
-    }
-    return tv.m_data.pobj;
-  }();
+  assertx(tvIsObject(tv));
+  auto const obj = tv.m_data.pobj;
   auto const prev = *ImplicitContext::activeCtx;
   *ImplicitContext::activeCtx = obj;
   vmStack().discard();
-
-  if (!prev) {
-    vmStack().pushNull();
-  } else {
-    vmStack().pushObject(prev);
-  }
-
-  // Decref after discarding so that if we are pushing the same object back,
-  // avoid refcount going to zero
+  vmStack().pushObject(prev);
   tvDecRefGen(tv);
 }
 

diff --git a/hphp/runtime/vm/jit/irgen-builtin.cpp b/hphp/runtime/vm/jit/irgen-builtin.cpp
@@ -1251,19 +1251,8 @@ SSATmp* opt_meth_caller_get_method(IRGS& env, const ParamPrep& params) {
 
 SSATmp* opt_get_implicit_context_memo_key(IRGS& env, const ParamPrep& params) {
   if (params.size() != 0) return nullptr;
-  return cond(
-    env,
-    [&] (Block* taken) {
-      auto const ctx = gen(env, LdImplicitContext);
-      return gen(env, CheckType, TObj, taken, ctx);
-    },
-    [&] (SSATmp* ctx) {
-      return gen(env, LdImplicitContextMemoKey, ctx);
-    },
-    [&] {
-      return cns(env, 0);
-    }
-  );
+  auto const ctx = gen(env, LdImplicitContext);
+  return gen(env, LdImplicitContextMemoKey, ctx);
 }
 
 SSATmp* opt_class_to_classname(IRGS& env, const ParamPrep& params) {
@@ -2643,7 +2632,7 @@ void emitSilence(IRGS& env, Id localId, SilenceOp subop) {
 
 void emitSetImplicitContextByValue(IRGS& env) {
   auto const tv = topC(env);
-  if (!tv->type().subtypeOfAny(TInitNull, TObj)) return interpOne(env);
+  if(!tv->isA(TObj)) return interpOne(env);
 
   auto const prev = gen(env, LdImplicitContext);
   gen(env, StImplicitContext, tv);

diff --git a/hphp/runtime/vm/jit/irlower-load-store.cpp b/hphp/runtime/vm/jit/irlower-load-store.cpp
@@ -267,19 +267,7 @@ void cgLdImplicitContext(IRLS& env, const IRInstruction* inst) {
   markRDSAccess(v, ImplicitContext::activeCtx.handle());
 
   auto const dst = dstLoc(env, inst, 0);
-  auto const sf = v.makeReg();
-  v << load{
-    rvmtl()[ImplicitContext::activeCtx.handle()],
-    dst.reg(0) /* data */
-  };
-  v << testq{dst.reg(0), dst.reg(0), sf};
-  v << cmovb{
-    CC_Z,
-    sf,
-    v.cns(TObj.toDataType()),
-    v.cns(TInitNull.toDataType()),
-    dst.reg(1) /* type */
-  };
+  v << load{rvmtl()[ImplicitContext::activeCtx.handle()], dst.reg(0)};
 }
 
 void cgLdImplicitContextMemoKey(IRLS& env, const IRInstruction* inst) {
@@ -292,25 +280,12 @@ void cgLdImplicitContextMemoKey(IRLS& env, const IRInstruction* inst) {
 
 void cgStImplicitContext(IRLS& env, const IRInstruction* inst) {
   auto& v = vmain(env);
-  auto const src = inst->src(0);
+  assertx(inst->src(0)->isA(TObj));
+
   auto const data = srcLoc(env, inst, 0).reg(0);
-  auto const type = srcLoc(env, inst, 0).reg(1);
   markRDSAccess(v, ImplicitContext::activeCtx.handle());
 
-  if (src->isA(TInitNull)) {
-    v << store{v.cns(nullptr), rvmtl()[ImplicitContext::activeCtx.handle()]};
-  } else if (src->isA(TObj)) {
-    v << store{data, rvmtl()[ImplicitContext::activeCtx.handle()]};
-  } else {
-    assertx(src->isA(TObj|TInitNull));
-    emitTypeTest(v, env, TInitNull, data, type, v.makeReg(),
-      [&] (ConditionCode cc, Vreg sf) {
-        auto const result = v.makeReg();
-        v << cmovq{cc, sf, v.cns(nullptr), data, result};
-        v << store{result, rvmtl()[ImplicitContext::activeCtx.handle()]};
-      }
-    );
-  }
+  v << store{data, rvmtl()[ImplicitContext::activeCtx.handle()]};
 }
 
 void cgDbgTrashMem(IRLS& env, const IRInstruction* inst) {