diff --git a/llvm/lib/Target/AVR/AVRAsmPrinter.cpp b/llvm/lib/Target/AVR/AVRAsmPrinter.cpp --- a/llvm/lib/Target/AVR/AVRAsmPrinter.cpp +++ b/llvm/lib/Target/AVR/AVRAsmPrinter.cpp @@ -24,6 +24,7 @@ #include "llvm/CodeGen/TargetRegisterInfo.h" #include "llvm/CodeGen/TargetSubtargetInfo.h" #include "llvm/IR/Mangler.h" +#include "llvm/MC/MCContext.h" #include "llvm/MC/MCInst.h" #include "llvm/MC/MCStreamer.h" #include "llvm/MC/MCSymbol.h" @@ -56,8 +57,11 @@ const MCExpr *lowerConstant(const Constant *CV) override; + void emitXXStructor(const DataLayout &DL, const Constant *CV) override; + private: const MCRegisterInfo &MRI; + bool EmittedStructorSymbolAttrs = false; }; void AVRAsmPrinter::printOperand(const MachineInstr *MI, unsigned OpNo, @@ -193,6 +197,25 @@ return AsmPrinter::lowerConstant(CV); } +void AVRAsmPrinter::emitXXStructor(const DataLayout &DL, const Constant *CV) { + if (!EmittedStructorSymbolAttrs) { + OutStreamer->emitRawComment( + " Emitting these undefined symbol references causes us to link the" + " libgcc code that runs our constructors/destructors"); + OutStreamer->emitRawComment(" This matches GCC's behavior"); + + MCSymbol *CtorsSym = OutContext.getOrCreateSymbol("__do_global_ctors"); + OutStreamer->emitSymbolAttribute(CtorsSym, MCSA_Global); + + MCSymbol *DtorsSym = OutContext.getOrCreateSymbol("__do_global_dtors"); + OutStreamer->emitSymbolAttribute(DtorsSym, MCSA_Global); + + EmittedStructorSymbolAttrs = true; + } + + AsmPrinter::emitXXStructor(DL, CV); +} + } // end of namespace llvm extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeAVRAsmPrinter() { diff --git a/llvm/test/CodeGen/AVR/ctors.ll b/llvm/test/CodeGen/AVR/ctors.ll new file mode 100644 --- /dev/null +++ b/llvm/test/CodeGen/AVR/ctors.ll @@ -0,0 +1,15 @@ +; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py +; RUN: llc < %s -march=avr | FileCheck %s + +define void @do_nothing() addrspace(1) #0 { +; CHECK-LABEL: do_nothing: +; CHECK: ; %bb.0: +; CHECK-NEXT: ret + ret void +} + +; CHECK: .globl __do_global_ctors +@llvm.global_ctors = appending global [1 x { i32, void () addrspace(1)*, i8* }] [{ i32, void () addrspace(1)*, i8* } { i32 65535, void () addrspace(1)* @do_nothing, i8* null }] + +; CHECK: .globl __do_global_dtors +@llvm.global_dtors = appending global [1 x { i32, void () addrspace(1)*, i8* }] [{ i32, void () addrspace(1)*, i8* } { i32 65535, void () addrspace(1)* @do_nothing, i8* null }]