https://github.com/Zhenhang1213 created https://github.com/llvm/llvm-project/pull/190885
Fixes https://github.com/llvm/llvm-project/issues/183916 >From 59e3e17964a88d16ac79222f0ba161fa77e46572 Mon Sep 17 00:00:00 2001 From: Austin <[email protected]> Date: Wed, 8 Apr 2026 10:00:16 +0800 Subject: [PATCH] [arm] using indirection got not pc-relative --- clang/test/Driver/weak-symbol-pic.c | 17 +++++++++++++++++ llvm/lib/Target/TargetMachine.cpp | 9 +++++++++ 2 files changed, 26 insertions(+) create mode 100644 clang/test/Driver/weak-symbol-pic.c diff --git a/clang/test/Driver/weak-symbol-pic.c b/clang/test/Driver/weak-symbol-pic.c new file mode 100644 index 0000000000000..44b8a55f0f0de --- /dev/null +++ b/clang/test/Driver/weak-symbol-pic.c @@ -0,0 +1,17 @@ +// RUN: %clang -fpic -S -target arm-linux-gnueabihf -o - %s | FileCheck %s +// RUN: %clang -fpic -S -target armeb-linux-gnueabihf -o - %s | FileCheck %s + +// Test that weak symbols use GOT relocations in PIC mode on ARM. +// This matches GCC behavior where weak symbols require GOT because they +// can be preempted at runtime. + +// CHECK: xxx(GOT_PREL) + +void __attribute__((__weak__)) xxx(void); + +void call_func(void (*f)(void)); + +int main() { + call_func(xxx); + return 0; +} \ No newline at end of file diff --git a/llvm/lib/Target/TargetMachine.cpp b/llvm/lib/Target/TargetMachine.cpp index 9243cdad43e1e..71602b2a262cd 100644 --- a/llvm/lib/Target/TargetMachine.cpp +++ b/llvm/lib/Target/TargetMachine.cpp @@ -212,6 +212,14 @@ bool TargetMachine::shouldAssumeDSOLocal(const GlobalValue *GV) const { if (!GV) return false; + // Weak symbols can be preempted at runtime, so don't assume they're DSO + // local. This is important for PIC code where we need GOT relocations for + // weak symbols. Only apply this fix for ARM targets to match GCC behavior. + if ((GV->hasWeakLinkage() || GV->hasExternalWeakLinkage()) && + (TT.getArch() == Triple::arm || TT.getArch() == Triple::armeb || + TT.getArch() == Triple::thumb || TT.getArch() == Triple::thumbeb)) + return false; + // If the IR producer requested that this GV be treated as dso local, obey. if (GV->isDSOLocal()) return true; @@ -251,6 +259,7 @@ bool TargetMachine::shouldAssumeDSOLocal(const GlobalValue *GV) const { assert(TT.isOSBinFormatELF() || TT.isOSBinFormatWasm() || TT.isOSBinFormatXCOFF()); + return false; } _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
