1//===-- MCAsmInfoDarwin.cpp - Darwin asm properties -------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines target asm properties related what form asm statements
11// should take in general on Darwin-based targets
12//
13//===----------------------------------------------------------------------===//
14
15#include "llvm/MC/MCAsmInfoDarwin.h"
16#include "llvm/MC/MCContext.h"
17#include "llvm/MC/MCExpr.h"
18#include "llvm/MC/MCSectionMachO.h"
19using namespace llvm;
20
21bool MCAsmInfoDarwin::isSectionAtomizableBySymbols(
22    const MCSection &Section) const {
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.getSectionName() == "__cfstring")
33    return false;
34
35  if (SMO.getSegmentName() == "__DATA" &&
36      SMO.getSectionName() == "__objc_classrefs")
37    return false;
38
39  switch (SMO.getType()) {
40  default:
41    return true;
42
43  // These sections are atomized at the element boundaries without using
44  // symbols.
45  case MachO::S_4BYTE_LITERALS:
46  case MachO::S_8BYTE_LITERALS:
47  case MachO::S_16BYTE_LITERALS:
48  case MachO::S_LITERAL_POINTERS:
49  case MachO::S_NON_LAZY_SYMBOL_POINTERS:
50  case MachO::S_LAZY_SYMBOL_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  HasWeakDefDirective = true;
73  HasWeakDefCanBeHiddenDirective = true;
74  WeakRefDirective = "\t.weak_reference ";
75  ZeroDirective = "\t.space\t";  // ".space N" emits N zeros.
76  HasMachoZeroFillDirective = true;  // Uses .zerofill
77  HasMachoTBSSDirective = true; // Uses .tbss
78  HasStaticCtorDtorReferenceInStaticMode = true;
79
80  // FIXME: Change this once MC is the system assembler.
81  HasAggressiveSymbolFolding = false;
82
83  HiddenVisibilityAttr = MCSA_PrivateExtern;
84  HiddenDeclarationVisibilityAttr = MCSA_Invalid;
85
86  // Doesn't support protected visibility.
87  ProtectedVisibilityAttr = MCSA_Invalid;
88
89  HasDotTypeDotSizeDirective = false;
90  HasNoDeadStrip = true;
91
92  DwarfUsesRelocationsAcrossSections = false;
93
94  UseIntegratedAssembler = true;
95  SetDirectiveSuppressesReloc = true;
96}
97