[PATCH] D104420: thread_local support for AIX

[Hubert Tong via Phabricator via cfe-commits]

hubert.reinterpretcast added inline comments.


================
Comment at: clang/lib/CodeGen/ItaniumCXXABI.cpp:4790
+    llvm::Value *Arg2 = llvm::ConstantExpr::getBitCast(
+        cast<llvm::Constant>(dtor.getCallee()), FpTy);
+    CGF.EmitNounwindRuntimeCall(AtExit, {Arg1, Arg2});
----------------
The function registered needs to be something more like what `createAtExitStub` stub creates. Otherwise, the destructor will not be able to reference `*this` correctly.

As it is, the registered function is currently just the destructor itself:
```
$ clang++ -target powerpc64-ibm-aix -emit-llvm -S -o - -xc++ -<<<$'struct A { ~A(); }; thread_local A a;' | grep -C2 __pt_atexit_np
define internal void @__cxx_global_var_init() #0 {
entry:
  %0 = call i32 (i32, i32 (i32, ...)*, ...) @__pt_atexit_np(i32 0, i32 (i32, ...)* bitcast (void (%struct.A*)* @_ZN1AD1Ev to i32 (i32, ...)*)) #3
  ret void
}
--
declare void @_ZN1AD1Ev(%struct.A* nonnull align 1 dereferenceable(1)) unnamed_addr #1

declare i32 @__pt_atexit_np(i32, i32 (i32, ...)*, ...)

; Function Attrs: noinline
Return:  0x00:0   Mon Jul 12 15:24:15 2021 EDT
```


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D104420/new/

https://reviews.llvm.org/D104420