forked from OSchip/llvm-project
89 lines
2.9 KiB
C++
89 lines
2.9 KiB
C++
//===- ConcatOutputSection.h ------------------------------------*- C++ -*-===//
|
|
//
|
|
// 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
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLD_MACHO_MERGED_OUTPUT_SECTION_H
|
|
#define LLD_MACHO_MERGED_OUTPUT_SECTION_H
|
|
|
|
#include "InputSection.h"
|
|
#include "OutputSection.h"
|
|
#include "lld/Common/LLVM.h"
|
|
#include "llvm/ADT/DenseMap.h"
|
|
#include "llvm/ADT/MapVector.h"
|
|
|
|
namespace lld {
|
|
namespace macho {
|
|
|
|
class Defined;
|
|
|
|
// Linking multiple files will inevitably mean resolving sections in different
|
|
// files that are labeled with the same segment and section name. This class
|
|
// contains all such sections and writes the data from each section sequentially
|
|
// in the final binary.
|
|
class ConcatOutputSection final : public OutputSection {
|
|
public:
|
|
explicit ConcatOutputSection(StringRef name)
|
|
: OutputSection(ConcatKind, name) {}
|
|
|
|
const ConcatInputSection *firstSection() const { return inputs.front(); }
|
|
const ConcatInputSection *lastSection() const { return inputs.back(); }
|
|
|
|
// These accessors will only be valid after finalizing the section
|
|
uint64_t getSize() const override { return size; }
|
|
uint64_t getFileSize() const override { return fileSize; }
|
|
|
|
void addInput(ConcatInputSection *input);
|
|
void finalize() override;
|
|
bool needsThunks() const;
|
|
uint64_t estimateStubsInRangeVA(size_t callIdx) const;
|
|
void eraseOmittedInputSections();
|
|
|
|
void writeTo(uint8_t *buf) const override;
|
|
|
|
std::vector<ConcatInputSection *> inputs;
|
|
std::vector<ConcatInputSection *> thunks;
|
|
|
|
static bool classof(const OutputSection *sec) {
|
|
return sec->kind() == ConcatKind;
|
|
}
|
|
|
|
private:
|
|
void finalizeFlags(InputSection *input);
|
|
|
|
size_t size = 0;
|
|
uint64_t fileSize = 0;
|
|
};
|
|
|
|
// We maintain one ThunkInfo per real function.
|
|
//
|
|
// The "active thunk" is represented by the sym/isec pair that
|
|
// turns-over during finalize(): as the call-site address advances,
|
|
// the active thunk goes out of branch-range, and we create a new
|
|
// thunk to take its place.
|
|
//
|
|
// The remaining members -- bools and counters -- apply to the
|
|
// collection of thunks associated with the real function.
|
|
|
|
struct ThunkInfo {
|
|
// These denote the active thunk:
|
|
Defined *sym = nullptr; // private-extern symbol for active thunk
|
|
ConcatInputSection *isec = nullptr; // input section for active thunk
|
|
|
|
// The following values are cumulative across all thunks on this function
|
|
uint32_t callSiteCount = 0; // how many calls to the real function?
|
|
uint32_t callSitesUsed = 0; // how many call sites processed so-far?
|
|
uint32_t thunkCallCount = 0; // how many call sites went to thunk?
|
|
uint8_t sequence = 0; // how many thunks created so-far?
|
|
};
|
|
|
|
extern llvm::DenseMap<Symbol *, ThunkInfo> thunkMap;
|
|
|
|
} // namespace macho
|
|
} // namespace lld
|
|
|
|
#endif
|