1 //===- MCSectionMachO.h - MachO Machine Code Sections -----------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file declares the MCSectionMachO class.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_MC_MCSECTIONMACHO_H
15 #define LLVM_MC_MCSECTIONMACHO_H
17 #include "llvm/MC/MCSection.h"
21 /// MCSectionMachO - This represents a section on a Mach-O system (used by
22 /// Mac OS X). On a Mac system, these are also described in
23 /// /usr/include/mach-o/loader.h.
24 class MCSectionMachO : public MCSection {
25 char SegmentName[16]; // Not necessarily null terminated!
26 char SectionName[16]; // Not necessarily null terminated!
28 /// TypeAndAttributes - This is the SECTION_TYPE and SECTION_ATTRIBUTES
29 /// field of a section, drawn from the enums below.
30 unsigned TypeAndAttributes;
32 /// Reserved2 - The 'reserved2' field of a section, used to represent the
33 /// size of stubs, for example.
36 MCSectionMachO(const StringRef &Segment, const StringRef &Section,
37 unsigned TAA, unsigned reserved2, SectionKind K)
38 : MCSection(K), TypeAndAttributes(TAA), Reserved2(reserved2) {
39 assert(Segment.size() <= 16 && Section.size() <= 16 &&
40 "Segment or section string too long");
41 for (unsigned i = 0; i != 16; ++i) {
42 if (i < Segment.size())
43 SegmentName[i] = Segment[i];
47 if (i < Section.size())
48 SectionName[i] = Section[i];
55 static MCSectionMachO *Create(const StringRef &Segment,
56 const StringRef &Section,
57 unsigned TypeAndAttributes,
59 SectionKind K, MCContext &Ctx);
61 /// These are the section type and attributes fields. A MachO section can
62 /// have only one Type, but can have any of the attributes specified.
64 // TypeAndAttributes bitmasks.
65 SECTION_TYPE = 0x000000FFU,
66 SECTION_ATTRIBUTES = 0xFFFFFF00U,
68 // Valid section types.
70 /// S_REGULAR - Regular section.
72 /// S_ZEROFILL - Zero fill on demand section.
74 /// S_CSTRING_LITERALS - Section with literal C strings.
75 S_CSTRING_LITERALS = 0x02U,
76 /// S_4BYTE_LITERALS - Section with 4 byte literals.
77 S_4BYTE_LITERALS = 0x03U,
78 /// S_8BYTE_LITERALS - Section with 8 byte literals.
79 S_8BYTE_LITERALS = 0x04U,
80 /// S_LITERAL_POINTERS - Section with pointers to literals.
81 S_LITERAL_POINTERS = 0x05U,
82 /// S_NON_LAZY_SYMBOL_POINTERS - Section with non-lazy symbol pointers.
83 S_NON_LAZY_SYMBOL_POINTERS = 0x06U,
84 /// S_LAZY_SYMBOL_POINTERS - Section with lazy symbol pointers.
85 S_LAZY_SYMBOL_POINTERS = 0x07U,
86 /// S_SYMBOL_STUBS - Section with symbol stubs, byte size of stub in
87 /// the Reserved2 field.
88 S_SYMBOL_STUBS = 0x08U,
89 /// S_SYMBOL_STUBS - Section with only function pointers for
91 S_MOD_INIT_FUNC_POINTERS = 0x09U,
92 /// S_MOD_INIT_FUNC_POINTERS - Section with only function pointers for
94 S_MOD_TERM_FUNC_POINTERS = 0x0AU,
95 /// S_COALESCED - Section contains symbols that are to be coalesced.
97 /// S_GB_ZEROFILL - Zero fill on demand section (that can be larger than 4
99 S_GB_ZEROFILL = 0x0CU,
100 /// S_INTERPOSING - Section with only pairs of function pointers for
102 S_INTERPOSING = 0x0DU,
103 /// S_16BYTE_LITERALS - Section with only 16 byte literals.
104 S_16BYTE_LITERALS = 0x0EU,
105 /// S_DTRACE_DOF - Section contains DTrace Object Format.
106 S_DTRACE_DOF = 0x0FU,
107 /// S_LAZY_DYLIB_SYMBOL_POINTERS - Section with lazy symbol pointers to
108 /// lazy loaded dylibs.
109 S_LAZY_DYLIB_SYMBOL_POINTERS = 0x10U,
111 LAST_KNOWN_SECTION_TYPE = S_LAZY_DYLIB_SYMBOL_POINTERS,
114 // Valid section attributes.
116 /// S_ATTR_PURE_INSTRUCTIONS - Section contains only true machine
118 S_ATTR_PURE_INSTRUCTIONS = 1U << 31,
119 /// S_ATTR_NO_TOC - Section contains coalesced symbols that are not to be
120 /// in a ranlib table of contents.
121 S_ATTR_NO_TOC = 1U << 30,
122 /// S_ATTR_STRIP_STATIC_SYMS - Ok to strip static symbols in this section
123 /// in files with the MY_DYLDLINK flag.
124 S_ATTR_STRIP_STATIC_SYMS = 1U << 29,
125 /// S_ATTR_NO_DEAD_STRIP - No dead stripping.
126 S_ATTR_NO_DEAD_STRIP = 1U << 28,
127 /// S_ATTR_LIVE_SUPPORT - Blocks are live if they reference live blocks.
128 S_ATTR_LIVE_SUPPORT = 1U << 27,
129 /// S_ATTR_SELF_MODIFYING_CODE - Used with i386 code stubs written on by
131 S_ATTR_SELF_MODIFYING_CODE = 1U << 26,
132 /// S_ATTR_DEBUG - A debug section.
133 S_ATTR_DEBUG = 1U << 25,
134 /// S_ATTR_SOME_INSTRUCTIONS - Section contains some machine instructions.
135 S_ATTR_SOME_INSTRUCTIONS = 1U << 10,
136 /// S_ATTR_EXT_RELOC - Section has external relocation entries.
137 S_ATTR_EXT_RELOC = 1U << 9,
138 /// S_ATTR_LOC_RELOC - Section has local relocation entries.
139 S_ATTR_LOC_RELOC = 1U << 8
142 StringRef getSegmentName() const {
143 // SegmentName is not necessarily null terminated!
145 return StringRef(SegmentName, 16);
146 return StringRef(SegmentName);
148 StringRef getSectionName() const {
149 // SectionName is not necessarily null terminated!
151 return StringRef(SectionName, 16);
152 return StringRef(SectionName);
155 unsigned getTypeAndAttributes() const { return TypeAndAttributes; }
156 unsigned getStubSize() const { return Reserved2; }
158 /// ParseSectionSpecifier - Parse the section specifier indicated by "Spec".
159 /// This is a string that can appear after a .section directive in a mach-o
160 /// flavored .s file. If successful, this fills in the specified Out
161 /// parameters and returns an empty string. When an invalid section
162 /// specifier is present, this returns a string indicating the problem.
163 static std::string ParseSectionSpecifier(StringRef Spec, // In.
164 StringRef &Segment, // Out.
165 StringRef &Section, // Out.
166 unsigned &TAA, // Out.
167 unsigned &StubSize); // Out.
169 virtual void PrintSwitchToSection(const MCAsmInfo &MAI,
170 raw_ostream &OS) const;
173 } // end namespace llvm