https://github.com/aokblast created https://github.com/llvm/llvm-project/pull/210507
MSCV does not support the -fPIC option. When it is passed, Clang falls back to PIC level 2 on x86_64 and to a static binary on AArch64. Without -fPIC, however, PIC is already enabled by default on both targets. As a result, the PCH (built with the default PIC level by toolchain hint) and the clang-repl instance (using the fallback PIC level) end up with different PIC settings, consuming a mismatch. Avoid passing -fPIC when targeting MSVC on Windows. This preserve the existing semantics, since PIC is already enabled by default, while ensuring that both the PCH and clang-repl use the same PIC level. >From 3b3fa1453b0655867ccd354e90d57efb05cf6c24 Mon Sep 17 00:00:00 2001 From: ShengYi Hung <[email protected]> Date: Sat, 18 Jul 2026 20:34:27 +0800 Subject: [PATCH] [Clang][Interpreter] Respect default setting on Windows MSCV does not support the -fPIC option. When it is passed, Clang falls back to PIC level 2 on x86_64 and to a static binary on AArch64. Without -fPIC, however, PIC is already enabled by default on both targets. As a result, the PCH (built with the default PIC level by toolchain hint) and the clang-repl instance (using the fallback PIC level) end up with different PIC settings, consuming a mismatch. Avoid passing -fPIC when targeting MSVC on Windows. This preserve the existing semantics, since PIC is already enabled by default, while ensuring that both the PCH and clang-repl use the same PIC level. --- clang/lib/Interpreter/Interpreter.cpp | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/clang/lib/Interpreter/Interpreter.cpp b/clang/lib/Interpreter/Interpreter.cpp index 933a68b50db41..0536fdcd548a2 100644 --- a/clang/lib/Interpreter/Interpreter.cpp +++ b/clang/lib/Interpreter/Interpreter.cpp @@ -53,6 +53,7 @@ #include "llvm/Support/VirtualFileSystem.h" #include "llvm/Support/raw_ostream.h" #include "llvm/TargetParser/Host.h" +#include "llvm/TargetParser/Triple.h" #include "llvm/Transforms/Utils/Cloning.h" // for CloneModule #define DEBUG_TYPE "clang-repl" @@ -228,8 +229,13 @@ IncrementalCompilerBuilder::create(std::string TT, // host symbol may be out of range when the JIT memory is mapped more than // 2GB away (as on FreeBSD), breaking tests such as // Interpreter/simple-exception.cpp. Insert before user arguments so it can - // still be overridden. - ClangArgv.insert(ClangArgv.begin() + 1, "-fPIC"); + // still be overridden. On Windows (excluding Cygwin/MinGW) an explicit + // -fPIC is an unsupported driver option that would drop non-x86_64 targets + // to PIC level 0; PIC is already the forced default there where relevant, + // so don't inject it. + llvm::Triple TargetTriple(TT); + if (!TargetTriple.isOSWindows() || TargetTriple.isOSCygMing()) + ClangArgv.insert(ClangArgv.begin() + 1, "-fPIC"); // Prepending -c to force the driver to do something if no action was // specified. By prepending we allow users to override the default _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
