1//===- MCAsmInfoDarwin.cpp - Darwin asm properties ------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file defines target asm properties related what form asm statements
10// should take in general on Darwin-based targets
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/MC/MCAsmInfoDarwin.h"
15#include "llvm/BinaryFormat/MachO.h"
16#include "llvm/MC/MCDirectives.h"
17#include "llvm/MC/MCSectionMachO.h"
18
19using namespace llvm;
20
21bool MCAsmInfoDarwin::isSectionAtomizableBySymbols(
22 const MCSection &Section) {
23 const MCSectionMachO &SMO = static_cast<const MCSectionMachO &>(Section);
24
25 // Sections holding 1 byte strings are atomized based on the data they
26 // contain.
27 // Sections holding 2 byte strings require symbols in order to be atomized.
28 // There is no dedicated section for 4 byte strings.
29 if (SMO.getType() == MachO::S_CSTRING_LITERALS)
30 return false;
31
32 if (SMO.getSegmentName() == "__DATA" && SMO.getName() == "__cfstring")
33 return false;
34
35 if (SMO.getSegmentName() == "__DATA" && SMO.getName() == "__objc_classrefs")
36 return false;
37
38 switch (SMO.getType()) {
39 default:
40 return true;
41
42 // These sections are atomized at the element boundaries without using
43 // symbols.
44 case MachO::S_4BYTE_LITERALS:
45 case MachO::S_8BYTE_LITERALS:
46 case MachO::S_16BYTE_LITERALS:
47 case MachO::S_LITERAL_POINTERS:
48 case MachO::S_NON_LAZY_SYMBOL_POINTERS:
49 case MachO::S_LAZY_SYMBOL_POINTERS:
50 case MachO::S_THREAD_LOCAL_VARIABLE_POINTERS:
51 case MachO::S_MOD_INIT_FUNC_POINTERS:
52 case MachO::S_MOD_TERM_FUNC_POINTERS:
53 case MachO::S_INTERPOSING:
54 return false;
55 }
56}
57
58MCAsmInfoDarwin::MCAsmInfoDarwin() {
59 // Common settings for all Darwin targets.
60 // Syntax:
61 LinkerPrivateGlobalPrefix = "l";
62 HasSingleParameterDotFile = false;
63 HasSubsectionsViaSymbols = true;
64
65 AlignmentIsInBytes = false;
66 COMMDirectiveAlignmentIsInBytes = false;
67 LCOMMDirectiveAlignmentType = LCOMM::Log2Alignment;
68 InlineAsmStart = " InlineAsm Start";
69 InlineAsmEnd = " InlineAsm End";
70
71 // Directives:
72 HasWeakDefCanBeHiddenDirective = true;
73 WeakRefDirective = "\t.weak_reference ";
74 ZeroDirective = "\t.space\t"; // ".space N" emits N zeros.
75
76 HiddenVisibilityAttr = MCSA_PrivateExtern;
77 HiddenDeclarationVisibilityAttr = MCSA_Invalid;
78
79 // Doesn't support protected visibility.
80 ProtectedVisibilityAttr = MCSA_Invalid;
81
82 HasDotTypeDotSizeDirective = false;
83 HasNoDeadStrip = true;
84
85 DwarfUsesRelocationsAcrossSections = false;
86 SetDirectiveSuppressesReloc = true;
87}
88