From f8a75ca667a1d27be2a304502edd01d064cce20a Mon Sep 17 00:00:00 2001
From: Jesse Schalken <me@jesseschalken.com>
Date: Wed, 21 Sep 2016 07:43:46 -0700
Subject: [PATCH] Fix "flexible array member in an otherwise empty struct"
 error on GCC 6.2
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Summary:
Fixes the following error on GCC 6.2:

```
In file included from /hphp/runtime/base/rds-header.h:24:0,
                 from /hphp/runtime/base/request-injection-data.h:20,
                 from /hphp/runtime/base/thread-info.h:24,
                 from /hphp/runtime/base/array-init.h:26,
                 from /hphp/system/systemlib.cpp:18:
/hphp/runtime/vm/bytecode.h: At global scope:
/hphp/runtime/vm/bytecode.h:128:26: error: flexible array member ‘HPHP::ExtraArgs::m_extraArgs’ in an otherwise empty ‘struct HPHP::ExtraArgs’
   TypedValue m_extraArgs[];
                          ^
/hphp/runtime/vm/bytecode.h:80:8: note: in the definition of ‘struct HPHP::ExtraArgs’
 struct ExtraArgs {
        ^~~~~~~~~
```

Closes #6933
Closes https://github.com/facebook/hhvm/pull/7374

Differential Revision: D3899402

Pulled By: aorenste

fbshipit-source-id: 9d7c7de1ee9607e50db584ac8a58b8aaa8cdf5fc
---
 hphp/runtime/vm/bytecode.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hphp/runtime/vm/bytecode.h b/hphp/runtime/vm/bytecode.h
index 6897ff2..22a3c5e 100644
--- a/hphp/runtime/vm/bytecode.h
+++ b/hphp/runtime/vm/bytecode.h
@@ -125,7 +125,7 @@ struct ExtraArgs {
   static void* allocMem(unsigned nargs);
 
 private:
-  TypedValue m_extraArgs[];
+  TypedValue m_extraArgs[0];
 };
 
 /*
diff -ur hhvm-HHVM-3.3.7/hphp/hhbbc/interp.cpp hhvm-HHVM-3.3.7-gcc6/hphp/hhbbc/interp.cpp
--- hhvm-HHVM-3.3.7/hphp/hhbbc/interp.cpp	2015-06-30 21:56:17.000000000 +0200
+++ hhvm-HHVM-3.3.7-gcc6/hphp/hhbbc/interp.cpp	2017-03-04 02:27:06.013033366 +0100
@@ -1998,26 +1998,53 @@
   push(env, TInitCell);
 }
 
-template<class Op>
-void floatFnImpl(ISS& env, Op op, Type nonConstType) {
+void in(ISS& env, const bc::Floor&) {
   auto const t1 = popC(env);
   auto const v1 = tv(t1);
   if (v1) {
     if (v1->m_type == KindOfDouble) {
       constprop(env);
-      return push(env, dval(op(v1->m_data.dbl)));
+      return push(env, dval(floor(v1->m_data.dbl)));
     }
     if (v1->m_type == KindOfInt64) {
       constprop(env);
-      return push(env, dval(op(static_cast<double>(v1->m_data.num))));
+      return push(env, dval(floor(static_cast<double>(v1->m_data.num))));
     }
   }
-  push(env, nonConstType);
+  push(env, TDbl);
 }
 
-void in(ISS& env, const bc::Floor&) { floatFnImpl(env, floor, TDbl); }
-void in(ISS& env, const bc::Ceil&)  { floatFnImpl(env, ceil, TDbl); }
-void in(ISS& env, const bc::Sqrt&)  { floatFnImpl(env, sqrt, TInitUnc); }
+void in(ISS& env, const bc::Ceil&)  {
+  auto const t1 = popC(env);
+  auto const v1 = tv(t1);
+  if (v1) {
+    if (v1->m_type == KindOfDouble) {
+      constprop(env);
+      return push(env, dval(ceil(v1->m_data.dbl)));
+    }
+    if (v1->m_type == KindOfInt64) {
+      constprop(env);
+      return push(env, dval(ceil(static_cast<double>(v1->m_data.num))));
+    }
+  }
+  push(env, TDbl);
+}
+
+void in(ISS& env, const bc::Sqrt&)  {
+  auto const t1 = popC(env);
+  auto const v1 = tv(t1);
+  if (v1) {
+    if (v1->m_type == KindOfDouble) {
+      constprop(env);
+      return push(env, dval(sqrt(v1->m_data.dbl)));
+    }
+    if (v1->m_type == KindOfInt64) {
+      constprop(env);
+      return push(env, dval(sqrt(static_cast<double>(v1->m_data.num))));
+    }
+  }
+  push(env, TInitUnc);
+}
 
 void in(ISS& env, const bc::CheckProp&) { push(env, TBool); }
 void in(ISS& env, const bc::InitProp& op) {
diff -ur hhvm-HHVM-3.3.7/hphp/runtime/vm/bytecode.cpp hhvm-HHVM-3.3.7-gcc6/hphp/runtime/vm/bytecode.cpp
--- hhvm-HHVM-3.3.7/hphp/runtime/vm/bytecode.cpp	2015-06-30 21:56:17.000000000 +0200
+++ hhvm-HHVM-3.3.7-gcc6/hphp/runtime/vm/bytecode.cpp	2017-03-04 02:29:34.796789697 +0100
@@ -7211,22 +7211,20 @@
   }
 }
 
-template<class Op>
-OPTBLD_INLINE void ExecutionContext::roundOpImpl(Op op) {
+OPTBLD_INLINE void ExecutionContext::iopFloor(IOP_ARGS) {
+  NEXT();
   TypedValue* val = vmStack().topTV();
 
   tvCastToDoubleInPlace(val);
-  val->m_data.dbl = op(val->m_data.dbl);
-}
-
-OPTBLD_INLINE void ExecutionContext::iopFloor(IOP_ARGS) {
-  NEXT();
-  roundOpImpl(floor);
+  val->m_data.dbl = floor(val->m_data.dbl);
 }
 
 OPTBLD_INLINE void ExecutionContext::iopCeil(IOP_ARGS) {
   NEXT();
-  roundOpImpl(ceil);
+  TypedValue* val = vmStack().topTV();
+
+  tvCastToDoubleInPlace(val);
+  val->m_data.dbl = ceil(val->m_data.dbl);
 }
 
 OPTBLD_INLINE void ExecutionContext::iopCheckProp(IOP_ARGS) {
diff -ur hhvm-HHVM-3.3.7/hphp/runtime/vm/jit/code-gen-x64.cpp hhvm-HHVM-3.3.7.gcc6/hphp/runtime/vm/jit/code-gen-x64.cpp
--- hhvm-HHVM-3.3.7/hphp/runtime/vm/jit/code-gen-x64.cpp	2015-06-30 21:56:17.000000000 +0200
+++ hhvm-HHVM-3.3.7.gcc6/hphp/runtime/vm/jit/code-gen-x64.cpp	2017-03-04 10:55:38.602703009 +0100
@@ -3785,7 +3785,8 @@
                                             : calleeNumParams + 1;
       v << kpcall{extra->knownPrologue, extra->callee, prologIndex};
     } else {
-      v << call{extra->knownPrologue};
+      RegSet argRegs;
+      v << call{extra->knownPrologue, argRegs};
     }
     return;
   }