llvm/lld/ELF/LinkerScript.h

//===- LinkerScript.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_ELF_LINKER_SCRIPT_H
#define LLD_ELF_LINKER_SCRIPT_H

#include "Config.h"
#include "InputSection.h"
#include "Writer.h"
#include "lld/Common/LLVM.h"
#include "lld/Common/Strings.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/MapVector.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Compiler.h"
#include <cstddef>
#include <cstdint>
#include <functional>
#include <memory>

namespace lld::elf {

class Defined;
class InputFile;
class InputSection;
class InputSectionBase;
class OutputSection;
class SectionBase;
class ThunkSection;
struct OutputDesc;
struct SectionClass;
struct SectionClassDesc;

// This represents an r-value in the linker script.
struct ExprValue { … };

// This represents an expression in the linker script.
// ScriptParser::readExpr reads an expression and returns an Expr.
// Later, we evaluate the expression by calling the function.
Expr;

// This enum is used to implement linker script SECTIONS command.
// https://sourceware.org/binutils/docs/ld/SECTIONS.html#SECTIONS
enum SectionsCommandKind { … };

struct SectionCommand { … };

// This represents ". = <expr>" or "<symbol> = <expr>".
struct SymbolAssignment : SectionCommand { … };

// Linker scripts allow additional constraints to be put on output sections.
// If an output section is marked as ONLY_IF_RO, the section is created
// only if its input sections are read-only. Likewise, an output section
// with ONLY_IF_RW is created if all input sections are RW.
enum class ConstraintKind { … };

// This struct is used to represent the location and size of regions of
// target memory. Instances of the struct are created by parsing the
// MEMORY command.
struct MemoryRegion { … };

// This struct represents one section match pattern in SECTIONS() command.
// It can optionally have negative match pattern for EXCLUDED_FILE command.
// Also it may be surrounded with SORT() command, so contains sorting rules.
class SectionPattern { … };

class InputSectionDescription : public SectionCommand { … };

// Represents BYTE(), SHORT(), LONG(), or QUAD().
struct ByteCommand : SectionCommand { … };

struct InsertCommand { … };

// A NOCROSSREFS/NOCROSSREFS_TO command that prohibits references between
// certain output sections.
struct NoCrossRefCommand { … };

struct PhdrsCommand { … };

class LinkerScript final { … };

} // end namespace lld::elf

#endif // LLD_ELF_LINKER_SCRIPT_H