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(StringRef Segment, StringRef Section,
37 unsigned TAA, unsigned reserved2, SectionKind K);
38 friend class MCContext;
41 /// These are the section type and attributes fields. A MachO section can
42 /// have only one Type, but can have any of the attributes specified.
44 // TypeAndAttributes bitmasks.
45 SECTION_TYPE = 0x000000FFU,
46 SECTION_ATTRIBUTES = 0xFFFFFF00U,
48 // Valid section types.
50 /// S_REGULAR - Regular section.
52 /// S_ZEROFILL - Zero fill on demand section.
54 /// S_CSTRING_LITERALS - Section with literal C strings.
55 S_CSTRING_LITERALS = 0x02U,
56 /// S_4BYTE_LITERALS - Section with 4 byte literals.
57 S_4BYTE_LITERALS = 0x03U,
58 /// S_8BYTE_LITERALS - Section with 8 byte literals.
59 S_8BYTE_LITERALS = 0x04U,
60 /// S_LITERAL_POINTERS - Section with pointers to literals.
61 S_LITERAL_POINTERS = 0x05U,
62 /// S_NON_LAZY_SYMBOL_POINTERS - Section with non-lazy symbol pointers.
63 S_NON_LAZY_SYMBOL_POINTERS = 0x06U,
64 /// S_LAZY_SYMBOL_POINTERS - Section with lazy symbol pointers.
65 S_LAZY_SYMBOL_POINTERS = 0x07U,
66 /// S_SYMBOL_STUBS - Section with symbol stubs, byte size of stub in
67 /// the Reserved2 field.
68 S_SYMBOL_STUBS = 0x08U,
69 /// S_SYMBOL_STUBS - Section with only function pointers for
71 S_MOD_INIT_FUNC_POINTERS = 0x09U,
72 /// S_MOD_INIT_FUNC_POINTERS - Section with only function pointers for
74 S_MOD_TERM_FUNC_POINTERS = 0x0AU,
75 /// S_COALESCED - Section contains symbols that are to be coalesced.
77 /// S_GB_ZEROFILL - Zero fill on demand section (that can be larger than 4
79 S_GB_ZEROFILL = 0x0CU,
80 /// S_INTERPOSING - Section with only pairs of function pointers for
82 S_INTERPOSING = 0x0DU,
83 /// S_16BYTE_LITERALS - Section with only 16 byte literals.
84 S_16BYTE_LITERALS = 0x0EU,
85 /// S_DTRACE_DOF - Section contains DTrace Object Format.
87 /// S_LAZY_DYLIB_SYMBOL_POINTERS - Section with lazy symbol pointers to
88 /// lazy loaded dylibs.
89 S_LAZY_DYLIB_SYMBOL_POINTERS = 0x10U,
90 /// S_THREAD_LOCAL_REGULAR - Section with ....
91 S_THREAD_LOCAL_REGULAR = 0x11U,
92 /// S_THREAD_LOCAL_ZEROFILL - Thread local zerofill section.
93 S_THREAD_LOCAL_ZEROFILL = 0x12U,
94 /// S_THREAD_LOCAL_VARIABLES - Section with thread local variable structure
96 S_THREAD_LOCAL_VARIABLES = 0x13U,
97 /// S_THREAD_LOCAL_VARIABLE_POINTERS - Section with ....
98 S_THREAD_LOCAL_VARIABLE_POINTERS = 0x14U,
99 /// S_THREAD_LOCAL_INIT_FUNCTION_POINTERS - Section with thread local
100 /// variable initialization pointers to functions.
101 S_THREAD_LOCAL_INIT_FUNCTION_POINTERS = 0x15U,
103 LAST_KNOWN_SECTION_TYPE = S_THREAD_LOCAL_INIT_FUNCTION_POINTERS,
106 // Valid section attributes.
108 /// S_ATTR_PURE_INSTRUCTIONS - Section contains only true machine
110 S_ATTR_PURE_INSTRUCTIONS = 1U << 31,
111 /// S_ATTR_NO_TOC - Section contains coalesced symbols that are not to be
112 /// in a ranlib table of contents.
113 S_ATTR_NO_TOC = 1U << 30,
114 /// S_ATTR_STRIP_STATIC_SYMS - Ok to strip static symbols in this section
115 /// in files with the MY_DYLDLINK flag.
116 S_ATTR_STRIP_STATIC_SYMS = 1U << 29,
117 /// S_ATTR_NO_DEAD_STRIP - No dead stripping.
118 S_ATTR_NO_DEAD_STRIP = 1U << 28,
119 /// S_ATTR_LIVE_SUPPORT - Blocks are live if they reference live blocks.
120 S_ATTR_LIVE_SUPPORT = 1U << 27,
121 /// S_ATTR_SELF_MODIFYING_CODE - Used with i386 code stubs written on by
123 S_ATTR_SELF_MODIFYING_CODE = 1U << 26,
124 /// S_ATTR_DEBUG - A debug section.
125 S_ATTR_DEBUG = 1U << 25,
126 /// S_ATTR_SOME_INSTRUCTIONS - Section contains some machine instructions.
127 S_ATTR_SOME_INSTRUCTIONS = 1U << 10,
128 /// S_ATTR_EXT_RELOC - Section has external relocation entries.
129 S_ATTR_EXT_RELOC = 1U << 9,
130 /// S_ATTR_LOC_RELOC - Section has local relocation entries.
131 S_ATTR_LOC_RELOC = 1U << 8
134 StringRef getSegmentName() const {
135 // SegmentName is not necessarily null terminated!
137 return StringRef(SegmentName, 16);
138 return StringRef(SegmentName);
140 StringRef getSectionName() const {
141 // SectionName is not necessarily null terminated!
143 return StringRef(SectionName, 16);
144 return StringRef(SectionName);
147 unsigned getTypeAndAttributes() const { return TypeAndAttributes; }
148 unsigned getStubSize() const { return Reserved2; }
150 unsigned getType() const { return TypeAndAttributes & SECTION_TYPE; }
151 bool hasAttribute(unsigned Value) const {
152 return (TypeAndAttributes & Value) != 0;
155 /// ParseSectionSpecifier - Parse the section specifier indicated by "Spec".
156 /// This is a string that can appear after a .section directive in a mach-o
157 /// flavored .s file. If successful, this fills in the specified Out
158 /// parameters and returns an empty string. When an invalid section
159 /// specifier is present, this returns a string indicating the problem.
160 static std::string ParseSectionSpecifier(StringRef Spec, // In.
161 StringRef &Segment, // Out.
162 StringRef &Section, // Out.
163 unsigned &TAA, // Out.
164 unsigned &StubSize); // Out.
166 virtual void PrintSwitchToSection(const MCAsmInfo &MAI,
167 raw_ostream &OS) const;
168 virtual bool UseCodeAlign() const;
170 static bool classof(const MCSection *S) {
171 return S->getVariant() == SV_MachO;
173 static bool classof(const MCSectionMachO *) { return true; }
176 } // end namespace llvm