Index: lib/CodeGen/CGDecl.cpp
===================================================================
--- lib/CodeGen/CGDecl.cpp
+++ lib/CodeGen/CGDecl.cpp
@@ -26,6 +26,7 @@
 #include "clang/AST/Decl.h"
 #include "clang/AST/DeclObjC.h"
 #include "clang/AST/DeclOpenMP.h"
+#include "clang/AST/RecursiveASTVisitor.h"
 #include "clang/Basic/SourceManager.h"
 #include "clang/Basic/TargetInfo.h"
 #include "clang/CodeGen/CGFunctionInfo.h"
@@ -1244,53 +1245,65 @@
   return emission;
 }
 
-/// Determines whether the given __block variable is potentially
-/// captured by the given expression.
-static bool isCapturedBy(const VarDecl &var, const Expr *e) {
-  // Skip the most common kinds of expressions that make
-  // hierarchy-walking expensive.
-  e = e->IgnoreParenCasts();
+static bool isCapturedBy(const VarDecl &, const Expr *);
 
-  if (const BlockExpr *be = dyn_cast<BlockExpr>(e)) {
-    const BlockDecl *block = be->getBlockDecl();
-    for (const auto &I : block->captures()) {
-      if (I.getVariable() == &var)
-        return true;
-    }
+class IsCapturedBy : public RecursiveASTVisitor<IsCapturedBy> {
+  bool IsCaptured = false;
+  const VarDecl &Var;
+  bool setCaptured() {
+    IsCaptured = true;
+    // End visitation early, we know it's captured.
+    return false;
+  }
 
+public:
+  IsCapturedBy(const VarDecl &Var) : Var(Var) {}
+  bool isCaptured() const { return IsCaptured; }
+
+  bool TraverseBlockExpr(BlockExpr *BE) {
+    const BlockDecl *Block = BE->getBlockDecl();
+    for (const auto &I : Block->captures())
+      if (I.getVariable() == &Var)
+        return setCaptured();
     // No need to walk into the subexpressions.
     return false;
   }
 
-  if (const StmtExpr *SE = dyn_cast<StmtExpr>(e)) {
+  bool TraverseStmtExpr(StmtExpr *SE) {
     const CompoundStmt *CS = SE->getSubStmt();
     for (const auto *BI : CS->body())
       if (const auto *E = dyn_cast<Expr>(BI)) {
-        if (isCapturedBy(var, E))
-            return true;
-      }
-      else if (const auto *DS = dyn_cast<DeclStmt>(BI)) {
-          // special case declarations
-          for (const auto *I : DS->decls()) {
-              if (const auto *VD = dyn_cast<VarDecl>((I))) {
-                const Expr *Init = VD->getInit();
-                if (Init && isCapturedBy(var, Init))
-                  return true;
-              }
+        if (isCapturedBy(Var, E))
+          return setCaptured();
+      } else if (const auto *DS = dyn_cast<DeclStmt>(BI)) {
+        // special case declarations
+        for (const auto *I : DS->decls()) {
+          if (const auto *VD = dyn_cast<VarDecl>((I))) {
+            const Expr *Init = VD->getInit();
+            if (Init && isCapturedBy(Var, Init))
+              return setCaptured();
           }
+        }
       }
       else
-        // FIXME. Make safe assumption assuming arbitrary statements cause capturing.
-        // Later, provide code to poke into statements for capture analysis.
-        return true;
-    return false;
+        // FIXME. Make safe assumption assuming arbitrary statements cause
+        // capturing. Later, provide code to poke into statements for capture
+        // analysis.
+        return setCaptured();
+    return true;
   }
+};
 
-  for (const Stmt *SubStmt : e->children())
-    if (isCapturedBy(var, cast<Expr>(SubStmt)))
-      return true;
+/// Determines whether the given __block variable is potentially
+/// captured by the given expression.
+static bool isCapturedBy(const VarDecl &Var, const Expr *E) {
+  // Skip the most common kinds of expressions that make
+  // hierarchy-walking expensive.
+  E = E->IgnoreParenCasts();
 
-  return false;
+  IsCapturedBy Visitor(Var);
+  Visitor.TraverseStmt(const_cast<Expr *>(E));
+  return Visitor.isCaptured();
 }
 
 /// Determine whether the given initializer is trivial in the sense
Index: test/CodeGen/block-capture.cpp
===================================================================
--- /dev/null
+++ test/CodeGen/block-capture.cpp
@@ -0,0 +1,13 @@
+// RUN: %clang_cc1 -x c++ -std=c++11 -fblocks -emit-llvm %s -o - | FileCheck %s
+
+// CHECK: %struct.__block_byref_baz = type { i8*, %struct.__block_byref_baz*, i32, i32, i32 }
+// CHECK: [[baz:%[0-9a-z_]*]] = alloca %struct.__block_byref_baz
+// CHECK: [[bazref:%[0-9a-z_\.]*]] = getelementptr inbounds %struct.__block_byref_baz, %struct.__block_byref_baz* [[baz]], i32 0, i32 1
+// CHECK: store %struct.__block_byref_baz* [[baz]], %struct.__block_byref_baz** [[bazref]]
+// CHECK: [[disposable:%[0-9a-z_]*]] = bitcast %struct.__block_byref_baz* [[baz]] to i8*
+// CHECK: call void @_Block_object_dispose(i8* [[disposable]]
+
+int main() {
+  __block int baz = [&]() { return 0; }();
+  return 0;
+}