[clang] 172464f - Revert "Reland "[ORC] Track __emutls_t definitions in IRMaterializationUnit" (#207161) (#208413)" (#209260)

[via cfe-commits]

Author: Paul Osmialowski
Date: 2026-07-13T20:07:01+01:00
New Revision: 172464f2b665bd169658fbafb10e61c1882042ff

URL: https://github.com/llvm/llvm-project/commit/172464f2b665bd169658fbafb10e61c1882042ff
DIFF: https://github.com/llvm/llvm-project/commit/172464f2b665bd169658fbafb10e61c1882042ff.diff

LOG: Revert "Reland "[ORC] Track __emutls_t definitions in IRMaterializationUnit" (#207161) (#208413)"  (#209260)

This causes the failures on various CIs with various archs a day before
branching.

Added: 
    

Modified: 
    clang/lib/Interpreter/IncrementalExecutor.cpp
    llvm/lib/ExecutionEngine/Orc/Layer.cpp

Removed: 
    clang/test/Interpreter/emulated-tls.cpp


################################################################################
diff  --git a/clang/lib/Interpreter/IncrementalExecutor.cpp b/clang/lib/Interpreter/IncrementalExecutor.cpp
index 8e64a3d73305e..65cb29a2f441a 100644
--- a/clang/lib/Interpreter/IncrementalExecutor.cpp
+++ b/clang/lib/Interpreter/IncrementalExecutor.cpp
@@ -27,7 +27,6 @@
 #include "llvm/ADT/Twine.h"
 
 #include "llvm/ExecutionEngine/JITLink/JITLinkMemoryManager.h"
-#include "llvm/ExecutionEngine/Orc/AbsoluteSymbols.h"
 #include "llvm/ExecutionEngine/Orc/Debugging/DebuggerSupport.h"
 #include "llvm/ExecutionEngine/Orc/EPCDynamicLibrarySearchGenerator.h"
 #include "llvm/ExecutionEngine/Orc/ExecutionUtils.h"
@@ -61,21 +60,6 @@
 #include <unistd.h>
 #endif
 
-// Address of the host's emulated-TLS runtime entry point, or null if the host
-// cannot provide one. On Darwin, __emutls_get_address lives in the compiler-rt
-// builtins archive; referencing it here force-links the archive member into
-// the binary. The reference must not exist elsewhere: MSVC has no emulated-TLS
-// runtime (the link would fail), and ELF hosts resolve it from libgcc_s /
-// compiler-rt through regular process-symbol lookup.
-#ifdef __APPLE__
-extern "C" void *__emutls_get_address(void *);
-static void *getEmuTLSGetAddressPtr() {
-  return reinterpret_cast<void *>(&__emutls_get_address);
-}
-#else
-static void *getEmuTLSGetAddressPtr() { return nullptr; }
-#endif
-
 namespace clang {
 IncrementalExecutorBuilder::~IncrementalExecutorBuilder() = default;
 
@@ -404,29 +388,6 @@ IncrementalExecutorBuilder::create(llvm::orc::ThreadSafeContext &TSC,
     if (!JB)
       return JB.takeError();
     JITBuilder = std::move(*JB);
-    // TODO: Switch to native TLS on Darwin once clang-repl can adopt the ORC
-    // runtime (which provides __emutls_get_address and supports the full TLS
-    // lifecycle). That will also remove the in-process-only constraint below.
-    //
-    // For MachO targets, thread_locals are lowered to emulated TLS, but the
-    // runtime (__emutls_get_address) lives in the compiler-rt builtins archive
-    // and nothing else in this process references it, so it isn't linked in
-    // and process-symbol lookup cannot find it. Define the force-linked host
-    // symbol (see getEmuTLSGetAddressPtr) as an absolute symbol so it is
-    // visible to JIT'd code. In-process execution only: the address is
-    // meaningless in an out-of-process executor.
-    if (void *EmuTLSGetAddress = getEmuTLSGetAddressPtr();
-        EmuTLSGetAddress && TT.isOSBinFormatMachO())
-      JITBuilder->setNotifyCreatedCallback(
-          [EmuTLSGetAddress](llvm::orc::LLJIT &J) {
-            auto &JD = J.getProcessSymbolsJITDylib()
-                           ? *J.getProcessSymbolsJITDylib()
-                           : J.getMainJITDylib();
-            return JD.define(llvm::orc::absoluteSymbols(
-                {{J.mangleAndIntern("__emutls_get_address"),
-                  {llvm::orc::ExecutorAddr::fromPtr(EmuTLSGetAddress),
-                   llvm::JITSymbolFlags::Exported}}}));
-          });
   }
 
   llvm::Error Err = llvm::Error::success();

diff  --git a/clang/test/Interpreter/emulated-tls.cpp b/clang/test/Interpreter/emulated-tls.cpp
deleted file mode 100644
index bd80b65957ee3..0000000000000
--- a/clang/test/Interpreter/emulated-tls.cpp
+++ /dev/null
@@ -1,28 +0,0 @@
-// REQUIRES: host-supports-jit
-// UNSUPPORTED: system-windows
-//
-// Emulated TLS is not supported by the LoongArch backend.
-// UNSUPPORTED: target=loongarch{{.*}}
-//
-// An inline function that odr-uses a non-zero-initialized thread_local is
-// emitted as a weak (linkonce_odr) definition into every PartialTranslationUnit
-// that references it. With emulated TLS that set includes an __emutls_t.<var>
-// symbol. When a later PTU re-defines the same weak set, ORC's
-// IRMaterializationUnit::discard() must find each duplicated symbol in its
-// SymbolToDefinition map. The emulated-TLS path used to register __emutls_t.<var>
-// in SymbolFlags but not SymbolToDefinition, so discarding it dereferenced
-// end() -- an assertion failure in +Asserts builds and heap corruption
-// otherwise. Two PTUs each pulling in the same inline worker reproduces it.
-//
-// RUN: cat %s | clang-repl | FileCheck %s
-
-extern "C" int printf(const char *, ...);
-template <int Tag> struct HeavyThing { static thread_local int tls; };
-template <int Tag> thread_local int HeavyThing<Tag>::tls = Tag + 1;
-inline int worker() { return HeavyThing<1>::tls; }
-int callA() { return worker(); }
-int callB() { return worker(); }
-auto r = printf("tls = %d, %d\n", callA(), callB());
-// CHECK: tls = 2, 2
-
-%quit

diff  --git a/llvm/lib/ExecutionEngine/Orc/Layer.cpp b/llvm/lib/ExecutionEngine/Orc/Layer.cpp
index 5e95b8c73b482..eb144275da589 100644
--- a/llvm/lib/ExecutionEngine/Orc/Layer.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/Layer.cpp
@@ -70,7 +70,6 @@ IRMaterializationUnit::IRMaterializationUnit(
 
           auto EmuTLST = Mangle(("__emutls_t." + GV.getName()).str());
           SymbolFlags[EmuTLST] = Flags;
-          SymbolToDefinition[EmuTLST] = &GV;
         }
         continue;
       }