https://github.com/pranavk created https://github.com/llvm/llvm-project/pull/217700
Guard the extern "C" declaration and reference to __emutls_get_address in IncrementalExecutor.cpp behind a new CMake option CLANG_ENABLE_EMUTLS_GET_ADDRESS, which is OFF by default. This prevents link errors in environments/runtimes where __emutls_get_address is not available. Replace all other guards with the new cmake option. >From 88e9770f9005c58f23f97c85f56e66c4b973ee2e Mon Sep 17 00:00:00 2001 From: Pranav Kant <[email protected]> Date: Thu, 20 Aug 2026 10:03:36 -0700 Subject: [PATCH] [clang-repl] Add CLANG_ENABLE_EMUTLS_GET_ADDRESS cmake option Guard the extern "C" declaration and reference to __emutls_get_address in IncrementalExecutor.cpp behind a new CMake option CLANG_ENABLE_EMUTLS_GET_ADDRESS, which is OFF by default. This prevents link errors in environments/runtimes where __emutls_get_address is not available. Replace all other guards with the new cmake option. --- clang/CMakeLists.txt | 3 +++ clang/include/clang/Config/config.h.cmake | 3 +++ clang/lib/Interpreter/IncrementalExecutor.cpp | 11 ++++------- .../gn/secondary/clang/include/clang/Config/BUILD.gn | 1 + .../clang/include/clang/Config/config.h | 3 +++ 5 files changed, 14 insertions(+), 7 deletions(-) diff --git a/clang/CMakeLists.txt b/clang/CMakeLists.txt index 89f584c5dceaa..e35f08467cde7 100644 --- a/clang/CMakeLists.txt +++ b/clang/CMakeLists.txt @@ -503,6 +503,9 @@ option(CLANG_ENABLE_PROTO_FUZZER "Build Clang protobuf fuzzer." OFF) option(CLANG_USE_EXPERIMENTAL_CONST_INTERP "Use the new experimental constant interpreter for compile-time evaluation." OFF) +option(CLANG_ENABLE_EMUTLS_GET_ADDRESS + "Enable linking __emutls_get_address into IncrementalExecutor for emulated TLS." OFF) + if (DEFINED CLANG_ENABLE_ARCMT) set(CLANG_ENABLE_OBJC_REWRITER ${CLANG_ENABLE_ARCMT}) message(DEPRECATION "'CLANG_ENABLE_ARCMT' is deprecated as ARCMigrate has been removed from Clang. Please use 'CLANG_ENABLE_OBJC_REWRITER' instead to enable or disable the Objective-C rewriter.") diff --git a/clang/include/clang/Config/config.h.cmake b/clang/include/clang/Config/config.h.cmake index 11b4096726f67..1c62e6fca8824 100644 --- a/clang/include/clang/Config/config.h.cmake +++ b/clang/include/clang/Config/config.h.cmake @@ -95,4 +95,7 @@ /* Enable the experimental new constant interpreter by default */ #cmakedefine01 CLANG_USE_EXPERIMENTAL_CONST_INTERP +/* Enable emutls get address workaround in IncrementalExecutor */ +#cmakedefine01 CLANG_ENABLE_EMUTLS_GET_ADDRESS + #endif diff --git a/clang/lib/Interpreter/IncrementalExecutor.cpp b/clang/lib/Interpreter/IncrementalExecutor.cpp index 6d337e7848699..b07c8f93fd355 100644 --- a/clang/lib/Interpreter/IncrementalExecutor.cpp +++ b/clang/lib/Interpreter/IncrementalExecutor.cpp @@ -17,6 +17,7 @@ #endif // __EMSCRIPTEN__ #include "clang/Basic/TargetInfo.h" +#include "clang/Config/config.h" #include "clang/Driver/Compilation.h" #include "clang/Driver/Driver.h" #include "clang/Driver/ToolChain.h" @@ -70,13 +71,9 @@ // in a static archive and nothing else references it, it is never linked in and // ORC's process-symbol lookup cannot resolve it. Referencing it here // force-links the archive member so it is present regardless of how the host -// provides it. Excluded where an emulated-TLS runtime is not guaranteed on the -// link line, so the reference would fail to link: non-Unix (MSVC has no such -// runtime), Emscripten (the wasm executor below does not use this JIT path), -// and AIX / z/OS (whose runtimes may not provide the symbol). On those hosts -// thread_locals instead rely on process-symbol lookup, unchanged from before. -#if defined(LLVM_ON_UNIX) && !defined(__EMSCRIPTEN__) && !defined(_AIX) && \ - !defined(__MVS__) && !defined(__FreeBSD__) +// provides it. Controlled by the CLANG_ENABLE_EMUTLS_GET_ADDRESS cmake option. +// When disabled, thread_locals instead rely on process-symbol lookup. +#if CLANG_ENABLE_EMUTLS_GET_ADDRESS extern "C" void *__emutls_get_address(void *); static void *getEmuTLSGetAddressPtr() { return reinterpret_cast<void *>(&__emutls_get_address); diff --git a/llvm/utils/gn/secondary/clang/include/clang/Config/BUILD.gn b/llvm/utils/gn/secondary/clang/include/clang/Config/BUILD.gn index f8196d1b248e5..83fd6d6a0f66f 100644 --- a/llvm/utils/gn/secondary/clang/include/clang/Config/BUILD.gn +++ b/llvm/utils/gn/secondary/clang/include/clang/Config/BUILD.gn @@ -32,6 +32,7 @@ write_cmake_config("Config") { "CLANG_SYSTEMZ_DEFAULT_ARCH=z10", "PPC_LINUX_DEFAULT_IEEELONGDOUBLE=", "CLANG_USE_EXPERIMENTAL_CONST_INTERP=", + "CLANG_ENABLE_EMUTLS_GET_ADDRESS=", ] if (clang_enable_static_analyzer) { diff --git a/utils/bazel/llvm-project-overlay/clang/include/clang/Config/config.h b/utils/bazel/llvm-project-overlay/clang/include/clang/Config/config.h index 7f7308f338966..03ef275c4ba39 100644 --- a/utils/bazel/llvm-project-overlay/clang/include/clang/Config/config.h +++ b/utils/bazel/llvm-project-overlay/clang/include/clang/Config/config.h @@ -105,6 +105,9 @@ /* Enable the experimental new constant interpreter by default */ #define CLANG_USE_EXPERIMENTAL_CONST_INTERP 0 +/* Enable emutls get address workaround in IncrementalExecutor */ +#define CLANG_ENABLE_EMUTLS_GET_ADDRESS 0 + /* Directly provide definitions here behind platform preprocessor definitions. * The preprocessor conditions are sufficient to handle all of the configuration * on platforms targeted by Bazel, and defining these here more faithfully _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
