From 46d6052cd771f3bd99d3e5a8d259114f1cc5f929 Mon Sep 17 00:00:00 2001
From: Reid Kleckner <rnk@google.com>
Date: Fri, 13 Oct 2017 16:55:14 +0000
Subject: [PATCH] [SEH] Use the SEH personality on frontend-outlined funclets

This allows __try inside __finally to work.

Fixes PR34939

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@315707 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/CGException.cpp        |  7 ++++++-
 test/CodeGenCXX/exceptions-seh.cpp | 21 +++++++++++++++++++++
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/lib/CodeGen/CGException.cpp b/lib/CodeGen/CGException.cpp
index 709ed00264..1bff6490b8 100644
--- a/lib/CodeGen/CGException.cpp
+++ b/lib/CodeGen/CGException.cpp
@@ -225,7 +225,12 @@ const EHPersonality &EHPersonality::get(CodeGenModule &CGM,
 }
 
 const EHPersonality &EHPersonality::get(CodeGenFunction &CGF) {
-  return get(CGF.CGM, dyn_cast_or_null<FunctionDecl>(CGF.CurCodeDecl));
+  const auto *FD = CGF.CurCodeDecl;
+  // For outlined finallys and filters, use the SEH personality in case they
+  // contain more SEH. This mostly only affects finallys. Filters could
+  // hypothetically use gnu statement expressions to sneak in nested SEH.
+  FD = FD ? FD : CGF.CurSEHParent;
+  return get(CGF.CGM, dyn_cast_or_null<FunctionDecl>(FD));
 }
 
 static llvm::Constant *getPersonalityFn(CodeGenModule &CGM,
diff --git a/test/CodeGenCXX/exceptions-seh.cpp b/test/CodeGenCXX/exceptions-seh.cpp
index 4f7eacd667..fa2d834c1e 100644
--- a/test/CodeGenCXX/exceptions-seh.cpp
+++ b/test/CodeGenCXX/exceptions-seh.cpp
@@ -76,6 +76,27 @@ extern "C" void use_seh() {
 // CHECK: [[cont]]
 // CHECK: br label %[[ret]]
 
+extern "C" void nested_finally() {
+  __try {
+    might_throw();
+  } __finally {
+    __try {
+      might_throw();
+    } __finally {
+    }
+  }
+}
+
+// CHECK-LABEL: define void @nested_finally() #{{[0-9]+}}
+// CHECK-SAME:  personality i8* bitcast (i32 (...)* @__C_specific_handler to i8*)
+// CHECK: invoke void @might_throw()
+// CHECK: call void @"\01?fin$0@0@nested_finally@@"(i8 1, i8* {{.*}})
+
+// CHECK-LABEL: define internal void @"\01?fin$0@0@nested_finally@@"
+// CHECK-SAME:  personality i8* bitcast (i32 (...)* @__C_specific_handler to i8*)
+// CHECK: invoke void @might_throw()
+// CHECK: call void @"\01?fin$1@0@nested_finally@@"(i8 1, i8* {{.*}})
+
 void use_seh_in_lambda() {
   ([]() {
     __try {
-- 
2.49.0