File: MCLinkerOptimizationHint.cpp

package info (click to toggle)
swiftlang 6.1.3-2
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid
  • size: 2,791,604 kB
  • sloc: cpp: 9,901,740; ansic: 2,201,431; asm: 1,091,827; python: 308,252; objc: 82,166; f90: 80,126; lisp: 38,358; pascal: 25,559; sh: 20,429; ml: 5,058; perl: 4,745; makefile: 4,484; awk: 3,535; javascript: 3,018; xml: 918; fortran: 664; cs: 573; ruby: 396
file content (59 lines) | stat: -rw-r--r-- 1,994 bytes parent folder | download | duplicates (6)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
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/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(const MCAssembler &Asm, raw_ostream &OutStream,
                               const MachObjectWriter &ObjWriter

) const {
  encodeULEB128(Kind, OutStream);
  encodeULEB128(Args.size(), OutStream);
  for (const MCSymbol *Arg : Args)
    encodeULEB128(ObjWriter.getSymbolAddress(*Arg, Asm), OutStream);
}

void MCLOHDirective::emit(const MCAssembler &Asm,
                          MachObjectWriter &ObjWriter) const {
  raw_ostream &OutStream = ObjWriter.W.OS;
  emit_impl(Asm, OutStream, ObjWriter);
}

uint64_t MCLOHDirective::getEmitSize(const MCAssembler &Asm,
                                     const MachObjectWriter &ObjWriter) 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(Asm, OutStream, ObjWriter);
  return OutStream.tell();
}