From a0fcc6d4cf52cd8e803c12e6d0acffde2c3641fe Mon Sep 17 00:00:00 2001
From: Michael Colavita <mcolavita@fb.com>
Date: Mon, 26 Oct 2020 18:19:20 -0700
Subject: [PATCH] Bespoke implementation of ClassGetTS

Summary: Implement ClassGetTS for bespokes.

Differential Revision: D24512398

fbshipit-source-id: f519cde6e972e5208cf16d7a83f10211f79cac47
---
 hphp/doc/ir.specification                       |  2 +-
 hphp/runtime/base/type-structure-helpers-defs.h |  7 +++
 hphp/runtime/vm/jit/irgen-basic.cpp             |  9 ----
 hphp/runtime/vm/jit/irgen-bespoke.cpp           | 59 ++++++++++++++++++++++++-
 4 files changed, 66 insertions(+), 11 deletions(-)

diff --git a/hphp/doc/ir.specification b/hphp/doc/ir.specification
index b36a4a5a73b..75e51261b19 100644
--- a/hphp/doc/ir.specification
+++ b/hphp/doc/ir.specification
@@ -3115,7 +3115,7 @@ fields of that struct for holding intermediate values.
 
   Throws an OutOfBoundsException if S0 is an undefined index for an array.
 
-| ThrowArrayKeyException, ND, S(DArr,Dict) S(Str), T
+| ThrowArrayKeyException, ND, S(DArr,Dict) S(Str), T|LA
 
   Throws an OutOfBoundsException if S0 is an undefined key for a darray or dict.
 
diff --git a/hphp/runtime/base/type-structure-helpers-defs.h b/hphp/runtime/base/type-structure-helpers-defs.h
index c6a4949cad9..e0eb5c0c2ec 100644
--- a/hphp/runtime/base/type-structure-helpers-defs.h
+++ b/hphp/runtime/base/type-structure-helpers-defs.h
@@ -42,6 +42,13 @@ const StaticString s_root_name("root_name");
 const StaticString s_alias("alias");
 const StaticString s_hh_this("HH\\this");
 
+// Fixed error messages
+const StaticString s_reified_type_must_be_ts(
+  "Reified type must be a type structure");
+const StaticString s_new_instance_of_not_string(
+  "You cannot create a new instance of this type as it is not a string");
+
+
 ///////////////////////////////////////////////////////////////////////////////
 
 namespace detail {
diff --git a/hphp/runtime/vm/jit/irgen-basic.cpp b/hphp/runtime/vm/jit/irgen-basic.cpp
index 7c4a7f1dced..3c8d724ef17 100644
--- a/hphp/runtime/vm/jit/irgen-basic.cpp
+++ b/hphp/runtime/vm/jit/irgen-basic.cpp
@@ -31,15 +31,6 @@
 
 namespace HPHP { namespace jit { namespace irgen {
 
-namespace {
-
-const StaticString s_reified_type_must_be_ts(
-  "Reified type must be a type structure");
-const StaticString s_new_instance_of_not_string(
-  "You cannot create a new instance of this type as it is not a string");
-
-} // namespace
-
 void emitClassGetC(IRGS& env) {
   auto const name = topC(env);
   if (!name->type().subtypeOfAny(TObj, TCls, TStr, TLazyCls)) {
diff --git a/hphp/runtime/vm/jit/irgen-bespoke.cpp b/hphp/runtime/vm/jit/irgen-bespoke.cpp
index a77328e6b69..256ccb7b728 100644
--- a/hphp/runtime/vm/jit/irgen-bespoke.cpp
+++ b/hphp/runtime/vm/jit/irgen-bespoke.cpp
@@ -18,6 +18,7 @@
 #include "hphp/runtime/base/bespoke-array.h"
 #include "hphp/runtime/base/bespoke/logging-array.h"
 #include "hphp/runtime/base/bespoke/logging-profile.h"
+#include "hphp/runtime/base/type-structure-helpers-defs.h"
 
 #include "hphp/runtime/vm/jit/analysis.h"
 #include "hphp/runtime/vm/jit/irgen-builtin.h"
@@ -458,6 +459,60 @@ void emitBespokeColFromArray(IRGS& env, CollectionType type) {
   push(env, col);
 }
 
+void emitBespokeClassGetTS(IRGS& env) {
+  auto const reqType = RO::EvalHackArrDVArrs ? TDict : TDArr;
+  auto const arr = topC(env);
+  auto const arrType = arr->type();
+  if (!(arrType <= reqType)) {
+    if (arrType.maybe(reqType)) {
+      PUNT(Bespoke-ClassGetTS-UnguardedTS);
+    } else {
+      gen(env, RaiseError, cns(env, s_reified_type_must_be_ts.get()));
+      return;
+    }
+  }
+
+  auto const layout = arrType.arrSpec().bespokeLayout();
+  ifElse(
+    env,
+    [&](Block* taken) {
+      layout->emitGet(env, arr, cns(env, s_generic_types.get()), taken);
+    },
+    [&] { gen(env, Jmp, makeExitSlow(env)); }
+  );
+
+  auto const classKey = cns(env, s_classname.get());
+  auto const classVal = cond(
+    env,
+    [&](Block* taken) {
+      return layout->emitGet(env, arr, classKey, taken);
+    },
+    [&] (SSATmp* val) { return val; },
+    [&] {
+      gen(env, ThrowArrayKeyException, arr, classKey);
+      return cns(env, TBottom);
+    }
+  );
+
+  auto const className = cond(
+    env,
+    [&] (Block* taken) {
+      return gen(env, CheckType, TStr, taken, classVal);
+    },
+    [&] (SSATmp* val) { return val; },
+    [&] {
+      hint(env, Block::Hint::Unlikely);
+      gen(env, RaiseError, cns(env, s_new_instance_of_not_string.get()));
+      return cns(env, TBottom);
+    }
+  );
+
+  auto const cls = ldCls(env, className);
+  popDecRef(env);
+  push(env, cls);
+  push(env, cns(env, TInitNull));
+}
+
 void translateDispatchBespoke(IRGS& env,
                               const NormalizedInstruction& ni) {
   auto const DEBUG_ONLY sk = ni.source;
@@ -490,8 +545,10 @@ void translateDispatchBespoke(IRGS& env,
     case Op::ColFromArray:
       emitBespokeColFromArray(env, (CollectionType) ni.imm[0].u_OA);
       return;
-    case Op::FCallBuiltin:
     case Op::ClassGetTS:
+      emitBespokeClassGetTS(env);
+      return;
+    case Op::FCallBuiltin:
       interpOne(env);
       return;
     case Op::IterInit:
-- 
2.11.4.GIT