[CodeGen] Sort llvm.global_ctors by lexing order before emission

Fixes https://github.com/llvm/llvm-project/issues/55804

The lexing order is already bookkept in DelayedCXXInitPosition but we
were not using it based on the wrong assumption that inline variable is
unordered. This patch fixes it by ordering entries in llvm.global_ctors
by orders in DelayedCXXInitPosition.

for llvm.global_ctors entries without a lexing order, ordering them by
the insertion order.

(This *mostly* orders the template instantiation in
https://reviews.llvm.org/D126341 intuitively, minus one tweak for which I'll
submit a separate patch.)

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D127233

1 files changed, 7 insertions, 2 deletions

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 9b97e890c352..74c14fed6575 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -47,6 +47,7 @@
 #include "clang/CodeGen/BackendUtil.h"
 #include "clang/CodeGen/ConstantInitBuilder.h"
 #include "clang/Frontend/FrontendDiagnostic.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
@@ -560,6 +561,9 @@ void CodeGenModule::Release() {
     if (PGOStats.hasDiagnostics())
       PGOStats.reportDiagnostics(getDiags(), getCodeGenOpts().MainFileName);
   }
+  llvm::stable_sort(GlobalCtors, [](const Structor &L, const Structor &R) {
+    return L.LexOrder < R.LexOrder;
+  });
   EmitCtorList(GlobalCtors, "llvm.global_ctors");
   EmitCtorList(GlobalDtors, "llvm.global_dtors");
   EmitGlobalAnnotations();
@@ -1579,9 +1583,10 @@ llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) {
 /// AddGlobalCtor - Add a function to the list that will be called before
 /// main() runs.
 void CodeGenModule::AddGlobalCtor(llvm::Function *Ctor, int Priority,
+                                  unsigned LexOrder,
                                   llvm::Constant *AssociatedData) {
   // FIXME: Type coercion of void()* types.
-  GlobalCtors.push_back(Structor(Priority, Ctor, AssociatedData));
+  GlobalCtors.push_back(Structor(Priority, LexOrder, Ctor, AssociatedData));
 }
 
 /// AddGlobalDtor - Add a function to the list that will be called
@@ -1595,7 +1600,7 @@ void CodeGenModule::AddGlobalDtor(llvm::Function *Dtor, int Priority,
   }
 
   // FIXME: Type coercion of void()* types.
-  GlobalDtors.push_back(Structor(Priority, Dtor, nullptr));
+  GlobalDtors.push_back(Structor(Priority, ~0U, Dtor, nullptr));
 }
 
 void CodeGenModule::EmitCtorList(CtorList &Fns, const char *GlobalName) {