From 31bb0f748b805f1e7ff73694fc63ace3e7876e19 Mon Sep 17 00:00:00 2001
From: Paul Bissonnette <paulbiss@fb.com>
Date: Thu, 6 Nov 2014 17:27:03 -0800
Subject: [PATCH] Check return types when returning inside try-finally

Summary: Adds a VerifyRetType{C,V} for finally trampoline.

Fixes #3998

Reviewed By: @JoelMarcey

Differential Revision: D1660033

Signature: t1:1660033:1415294884:3426c5634ca6a09f8fcf74a2b50943ae8e1ac52b
---
 hphp/compiler/analysis/emitter.cpp                         | 11 +++++++++++
 hphp/test/slow/return_statement/finally-typecheck.php      | 14 ++++++++++++++
 .../slow/return_statement/finally-typecheck.php.expectf    |  3 +++
 3 files changed, 28 insertions(+)
 create mode 100644 hphp/test/slow/return_statement/finally-typecheck.php
 create mode 100644 hphp/test/slow/return_statement/finally-typecheck.php.expectf

diff --git a/hphp/compiler/analysis/emitter.cpp b/hphp/compiler/analysis/emitter.cpp
index 303f4d9fea5..7aaa7817361 100644
--- a/hphp/compiler/analysis/emitter.cpp
+++ b/hphp/compiler/analysis/emitter.cpp
@@ -1611,6 +1611,11 @@ void EmitterVisitor::emitReturnTrampoline(Emitter& e,
   auto& t = region->m_returnTargets[sym].target;
   cases[t->m_state]->set(e);
 
+  bool hasConstraint = m_curFunc->retTypeConstraint.hasConstraint();
+  if (m_curFunc->isGenerator) {
+    // Suppress return type checking for generators
+    hasConstraint = false;
+  }
   IterVec iters;
   // We are emitting a case in a finally epilogue, therefore skip
   // the current try region and start from its parent
@@ -1628,10 +1633,16 @@ void EmitterVisitor::emitReturnTrampoline(Emitter& e,
       emitVirtualLocal(retLocal);
       if (sym == StackSym::C) {
         e.CGetL(retLocal);
+        if (hasConstraint) {
+          e.VerifyRetTypeC();
+        }
         e.RetC();
       } else {
         assert(sym == StackSym::V);
         e.VGetL(retLocal);
+        if (hasConstraint) {
+          e.VerifyRetTypeV();
+        }
         e.RetV();
       }
       return;
diff --git a/hphp/test/slow/return_statement/finally-typecheck.php b/hphp/test/slow/return_statement/finally-typecheck.php
new file mode 100644
index 00000000000..04ce28eef1a
--- /dev/null
+++ b/hphp/test/slow/return_statement/finally-typecheck.php
@@ -0,0 +1,14 @@
+<?hh
+
+class A {}
+class B {}
+
+function foo(): A {
+  try {
+    return new B;
+  } finally {
+    echo "finally\n";
+  }
+}
+
+var_dump(foo());
diff --git a/hphp/test/slow/return_statement/finally-typecheck.php.expectf b/hphp/test/slow/return_statement/finally-typecheck.php.expectf
new file mode 100644
index 00000000000..447b7bbdfe7
--- /dev/null
+++ b/hphp/test/slow/return_statement/finally-typecheck.php.expectf
@@ -0,0 +1,3 @@
+finally
+
+Catchable fatal error: Value returned from function foo() must be of type A, B given in %s/finally-typecheck.php on line 11
-- 
2.11.4.GIT