================ @@ -1642,6 +1642,101 @@ void AsmPrinter::emitStackUsage(const MachineFunction &MF) { *StackUsageStream << "static\n"; } +/// Extracts a generalized numeric type identifier of a Function's type from +/// type metadata. Returns null if metadata cannot be found. +static ConstantInt *extractNumericCGTypeId(const Function &F) { + SmallVector<MDNode *, 2> Types; + F.getMetadata(LLVMContext::MD_type, Types); + MDString *MDGeneralizedTypeId = nullptr; + for (const auto &Type : Types) { + if (Type->getNumOperands() == 2 && isa<MDString>(Type->getOperand(1))) { + auto *TMDS = cast<MDString>(Type->getOperand(1)); + if (TMDS->getString().ends_with(".generalized")) { + MDGeneralizedTypeId = TMDS; + break; + } + } + } + + if (!MDGeneralizedTypeId) + return nullptr; + + uint64_t TypeIdVal = llvm::MD5Hash(MDGeneralizedTypeId->getString()); + IntegerType *Int64Ty = Type::getInt64Ty(F.getContext()); + return ConstantInt::get(Int64Ty, TypeIdVal); +} + +/// Emits call graph section. +void AsmPrinter::emitCallGraphSection(const MachineFunction &MF, + FunctionInfo &FuncInfo) { + if (!MF.getTarget().Options.EmitCallGraphSection) + return; + + // Switch to the call graph section for the function + MCSection *FuncCGSection = + getObjFileLowering().getCallGraphSection(*getCurrentSection()); + assert(FuncCGSection && "null call graph section"); + OutStreamer->pushSection(); + OutStreamer->switchSection(FuncCGSection); + + // Emit format version number. + OutStreamer->emitInt64(0); + + // Emit function's self information, which is composed of: + // 1) FunctionEntryPc + // 2) FunctionKind: Whether the function is indirect target, and if so, + // whether its type id is known. + // 3) FunctionTypeId: Emit only when the function is an indirect target + // and its type id is known. + + // Emit function entry pc. + const MCSymbol *FunctionSymbol = getFunctionBegin(); + OutStreamer->emitSymbolValue(FunctionSymbol, TM.getProgramPointerSize()); + + // If this function has external linkage or has its address taken and + // it is not a callback, then anything could call it. + const Function &F = MF.getFunction(); + bool IsIndirectTarget = + !F.hasLocalLinkage() || F.hasAddressTaken(nullptr, + /*IgnoreCallbackUses=*/true, + /*IgnoreAssumeLikeCalls=*/true, + /*IgnoreLLVMUsed=*/false); + + // FIXME: FunctionKind takes a few values but emitted as a 64-bit value. + // Can be optimized to occupy 2 bits instead. + // Emit function kind, and type id if available. + if (!IsIndirectTarget) { + OutStreamer->emitInt64( + static_cast<uint64_t>(FunctionInfo::FunctionKind::NOT_INDIRECT_TARGET)); ---------------- ilovepi wrote:
Why leave this for future work? not opposed, but unclear why not now, given this PR has been up for review for ~6 months? https://github.com/llvm/llvm-project/pull/87576 _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits