From 1f669d35fc1f93f48fda419801034248c6412205 Mon Sep 17 00:00:00 2001
From: Jonas Hahnfeld <jonas.hahnfeld@cern.ch>
Date: Fri, 28 Jul 2023 15:43:11 +0200
Subject: [PATCH] [CodeGen] Keep track of eagerly emitted globals

An inline virtual function must be emitted, but we need to remember
it and emit the same definition again in the future in case later
LLVM optimizations stripped it from the Module. The added test case
shows the problem; before this patch, it would fail with:
    Symbols not found: [ _ZN1AD0Ev, _ZN1AD1Ev ]

This reapplies commit f8dadefd4a, reverted in commit 0e17372b38, but
disables RTTI in the test to avoid problems on Windows.

Differential Revision: https://reviews.llvm.org/D156537

(cherry picked from commit c861d32d7c2791bdc058d9d9fbaecc1c2f07b8c7)
---
 clang/lib/CodeGen/CodeGenModule.cpp       |  1 +
 clang/test/Interpreter/inline-virtual.cpp | 24 ++++++++++++++++++++++++
 2 files changed, 25 insertions(+)
 create mode 100644 clang/test/Interpreter/inline-virtual.cpp

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 8bb9b45..a3506df 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -3645,6 +3645,7 @@ void CodeGenModule::EmitGlobal(GlobalDecl GD) {
   if (MustBeEmitted(Global) && MayBeEmittedEagerly(Global)) {
     // Emit the definition if it can't be deferred.
     EmitGlobalDefinition(GD);
+    addEmittedDeferredDecl(GD);
     return;
   }
 
diff --git a/clang/test/Interpreter/inline-virtual.cpp b/clang/test/Interpreter/inline-virtual.cpp
new file mode 100644
index 0000000..79ab8ed
--- /dev/null
+++ b/clang/test/Interpreter/inline-virtual.cpp
@@ -0,0 +1,24 @@
+// REQUIRES: host-supports-jit
+// UNSUPPORTED: system-aix
+//
+// We disable RTTI to avoid problems on Windows for non-RTTI builds of LLVM
+// where the JIT cannot find ??_7type_info@@6B@.
+// RUN: cat %s | clang-repl -Xcc -fno-rtti | FileCheck %s
+// RUN: cat %s | clang-repl -Xcc -fno-rtti -Xcc -O2 | FileCheck %s
+
+extern "C" int printf(const char *, ...);
+
+struct A { int a; A(int a) : a(a) {} virtual ~A(); };
+
+// Then define the virtual destructor as inline out-of-line, in a separate
+// PartialTranslationUnit.
+inline A::~A() { printf("~A(%d)\n", a); }
+
+// Create one instance with new and delete it.
+A *a1 = new A(1);
+delete a1;
+// CHECK: ~A(1)
+
+// Also create one global that will be auto-destructed.
+A a2(2);
+// CHECK: ~A(2)
-- 
2.7.4