[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, 3 deletions

diff --git a/clang/lib/CodeGen/CodeGenModule.h b/clang/lib/CodeGen/CodeGenModule.h
index 14c791f..f57afdc 100644
--- a/clang/lib/CodeGen/CodeGenModule.h
+++ b/clang/lib/CodeGen/CodeGenModule.h
@@ -282,12 +282,15 @@ class CodeGenModule : public CodeGenTypeCache {
 
 public:
   struct Structor {
-    Structor() : Priority(0), Initializer(nullptr), AssociatedData(nullptr) {}
-    Structor(int Priority, llvm::Constant *Initializer,
+    Structor()
+        : Priority(0), LexOrder(~0u), Initializer(nullptr),
+          AssociatedData(nullptr) {}
+    Structor(int Priority, unsigned LexOrder, llvm::Constant *Initializer,
              llvm::Constant *AssociatedData)
-        : Priority(Priority), Initializer(Initializer),
+        : Priority(Priority), LexOrder(LexOrder), Initializer(Initializer),
           AssociatedData(AssociatedData) {}
     int Priority;
+    unsigned LexOrder;
     llvm::Constant *Initializer;
     llvm::Constant *AssociatedData;
   };
@@ -1602,6 +1605,7 @@ private:
 
   // FIXME: Hardcoding priority here is gross.
   void AddGlobalCtor(llvm::Function *Ctor, int Priority = 65535,
+                     unsigned LexOrder = ~0U,
                      llvm::Constant *AssociatedData = nullptr);
   void AddGlobalDtor(llvm::Function *Dtor, int Priority = 65535,
                      bool IsDtorAttrFunc = false);