diff options
Diffstat (limited to 'contrib/llvm-project/llvm/lib/MC/MCLinkerOptimizationHint.cpp')
-rw-r--r-- | contrib/llvm-project/llvm/lib/MC/MCLinkerOptimizationHint.cpp | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/contrib/llvm-project/llvm/lib/MC/MCLinkerOptimizationHint.cpp b/contrib/llvm-project/llvm/lib/MC/MCLinkerOptimizationHint.cpp new file mode 100644 index 000000000000..9ab321872b11 --- /dev/null +++ b/contrib/llvm-project/llvm/lib/MC/MCLinkerOptimizationHint.cpp @@ -0,0 +1,59 @@ +//===- llvm/MC/MCLinkerOptimizationHint.cpp ----- LOH handling ------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#include "llvm/MC/MCLinkerOptimizationHint.h" +#include "llvm/MC/MCAsmLayout.h" +#include "llvm/MC/MCMachObjectWriter.h" +#include "llvm/Support/LEB128.h" +#include "llvm/Support/raw_ostream.h" +#include <cstddef> +#include <cstdint> + +using namespace llvm; + +// Each LOH is composed by, in this order (each field is encoded using ULEB128): +// - Its kind. +// - Its number of arguments (let say N). +// - Its arg1. +// - ... +// - Its argN. +// <arg1> to <argN> are absolute addresses in the object file, i.e., +// relative addresses from the beginning of the object file. +void MCLOHDirective::emit_impl(raw_ostream &OutStream, + const MachObjectWriter &ObjWriter, + const MCAsmLayout &Layout) const { + encodeULEB128(Kind, OutStream); + encodeULEB128(Args.size(), OutStream); + for (const MCSymbol *Arg : Args) + encodeULEB128(ObjWriter.getSymbolAddress(*Arg, Layout), OutStream); +} + +void MCLOHDirective::emit(MachObjectWriter &ObjWriter, + const MCAsmLayout &Layout) const { + raw_ostream &OutStream = ObjWriter.W.OS; + emit_impl(OutStream, ObjWriter, Layout); +} + +uint64_t MCLOHDirective::getEmitSize(const MachObjectWriter &ObjWriter, + const MCAsmLayout &Layout) const { + class raw_counting_ostream : public raw_ostream { + uint64_t Count = 0; + + void write_impl(const char *, size_t size) override { Count += size; } + + uint64_t current_pos() const override { return Count; } + + public: + raw_counting_ostream() = default; + ~raw_counting_ostream() override { flush(); } + }; + + raw_counting_ostream OutStream; + emit_impl(OutStream, ObjWriter, Layout); + return OutStream.tell(); +} |