From f0aa361c37b10a84983f63adf9a88f66f9efee57 Mon Sep 17 00:00:00 2001
From: Oguz Ulgen <oulgen@fb.com>
Date: Sun, 13 Dec 2020 14:50:23 -0800
Subject: [PATCH] Kill inout and provenance things in fcallbuiltin

Summary: The remaining FCallBuiltins do not use inout and dont have array provenance skip frame effects. Lets kill this code to make it easier to port this behavior to FCallFuncD.

Reviewed By: ricklavoie

Differential Revision: D25254447

fbshipit-source-id: f88fab83685c838079cb19c633d2f9a81e22fadf
---
 hphp/hhbbc/interp-builtin.cpp | 81 ++++---------------------------------------
 1 file changed, 6 insertions(+), 75 deletions(-)

diff --git a/hphp/hhbbc/interp-builtin.cpp b/hphp/hhbbc/interp-builtin.cpp
index 4f551b0c016..dddab490855 100644
--- a/hphp/hhbbc/interp-builtin.cpp
+++ b/hphp/hhbbc/interp-builtin.cpp
@@ -505,6 +505,7 @@ bool is_optimizable_builtin(const php::Func* func) {
 namespace interp_step {
 
 void in(ISS& env, const bc::FCallBuiltin& op) {
+  always_assert(op.arg2 == 0);
   auto const name = op.str3;
   auto const func = env.index.resolve_func(env.ctx, name);
   auto const exactFunc = func.exactFunc();
@@ -514,70 +515,10 @@ void in(ISS& env, const bc::FCallBuiltin& op) {
     if (auto val = const_fold(env, op.arg1, 0, *exactFunc, true)) {
       constprop(env);
 
-      auto const needsRuntimeProvenance =
-        RO::EvalArrayProvenance &&
-        exactFunc->attrs & AttrProvenanceSkipFrame;
-
-      auto const popInArgs = [&](BytecodeVec& bcs) {
-        for (uint32_t i = 0; i < op.arg1; ++i) {
-          // FCallBuiltin has CU flavored args, so we need to check the
-          // type to know how to pop them.
-          auto const& popped = topT(env, i);
-          if (popped.subtypeOf(BUninit)) {
-            bcs.push_back(bc::PopU {});
-          } else {
-            assertx(popped.subtypeOf(BInitCell));
-            bcs.push_back(bc::PopC {});
-          }
-        }
-      };
-
-      // If there's no in-out parameters, we're done and can just push
-      // the result.
-      if (!op.arg2) {
-        if (needsRuntimeProvenance) {
-          BytecodeVec repl;
-          popInArgs(repl);
-          repl.push_back(gen_constant(*tv(*val)));
-          repl.push_back(bc::Int { 0 });
-          repl.push_back(bc::TagProvenanceHere {});
-          return reduce(env, std::move(repl));
-        }
-        discard(env, op.arg1);
-        return push(env, std::move(*val));
-      }
-
-      // Otherwise what we got from evaluating the function is
-      // actually a tuple of all the results. We need to extract the
-      // values out of the tuple and push them onto the stack in their
-      // proper order.
-      auto const v = tv(*val);
-      assertx(v);
-
-      assertx(tvIsHAMSafeVArray(*v));
-      auto const ad = v->m_data.parr;
-      assertx(ad->isStatic());
-      assertx(ad->size() == op.arg2 + 1);
-
-      BytecodeVec repl;
-      popInArgs(repl);
-
-      // Pop the placeholder uninit values
-      for (uint32_t i = 0; i < op.arg2; ++i) {
-        repl.push_back(bc::PopU {});
-      }
-      // Push the in-out returns
-      for (uint32_t i = 0; i < op.arg2; ++i) {
-        repl.push_back(gen_constant(ad->nvGetVal(op.arg2 - i)));
-      }
-      // Push the actual result, tagging it in ProvenanceSkipFrame functions.
-      repl.push_back(gen_constant(ad->nvGetVal(0)));
-      if (needsRuntimeProvenance) {
-        repl.push_back(bc::Int { 0 });
-        repl.push_back(bc::TagProvenanceHere {});
-      }
-
-      return reduce(env, std::move(repl));
+      always_assert(!RO::EvalArrayProvenance ||
+                    !(exactFunc->attrs & AttrProvenanceSkipFrame));
+      discard(env, op.arg1);
+      return push(env, std::move(*val));
     }
   }
 
@@ -614,17 +555,7 @@ void in(ISS& env, const bc::FCallBuiltin& op) {
     return *precise_ty;
   }();
 
-  auto const num_out = op.arg2;
-  for (auto i = uint32_t{0}; i < num_args + num_out; ++i) popT(env);
-
-  for (auto i = num_out; i > 0; --i) {
-    if (exactFunc) {
-      push(env, native_function_out_type(exactFunc, i - 1));
-    } else {
-      push(env, TInitCell);
-    }
-  }
-
+  for (auto i = uint32_t{0}; i < num_args; ++i) popT(env);
   push(env, rt);
 }
 
-- 
2.11.4.GIT