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/ADT/StringRef.h"
18 #include "llvm/MC/MCSection.h"
22 /// MCSectionMachO - This represents a section on a Mach-O system (used by
23 /// Mac OS X). On a Mac system, these are also described in
24 /// /usr/include/mach-o/loader.h.
25 class MCSectionMachO : public MCSection {
26 char SegmentName[16]; // Not necessarily null terminated!
27 char SectionName[16]; // Not necessarily null terminated!
29 /// TypeAndAttributes - This is the SECTION_TYPE and SECTION_ATTRIBUTES
30 /// field of a section, drawn from the enums below.
31 unsigned TypeAndAttributes;
33 /// Reserved2 - The 'reserved2' field of a section, used to represent the
34 /// size of stubs, for example.
37 MCSectionMachO(StringRef Segment, StringRef Section,
38 unsigned TAA, unsigned reserved2, SectionKind K);
39 friend class MCContext;
42 /// These are the section type and attributes fields. A MachO section can
43 /// have only one Type, but can have any of the attributes specified.
45 // TypeAndAttributes bitmasks.
46 SECTION_TYPE = 0x000000FFU,
47 SECTION_ATTRIBUTES = 0xFFFFFF00U,
49 // Valid section types.
51 /// S_REGULAR - Regular section.
53 /// S_ZEROFILL - Zero fill on demand section.
55 /// S_CSTRING_LITERALS - Section with literal C strings.
56 S_CSTRING_LITERALS = 0x02U,
57 /// S_4BYTE_LITERALS - Section with 4 byte literals.
58 S_4BYTE_LITERALS = 0x03U,
59 /// S_8BYTE_LITERALS - Section with 8 byte literals.
60 S_8BYTE_LITERALS = 0x04U,
61 /// S_LITERAL_POINTERS - Section with pointers to literals.
62 S_LITERAL_POINTERS = 0x05U,
63 /// S_NON_LAZY_SYMBOL_POINTERS - Section with non-lazy symbol pointers.
64 S_NON_LAZY_SYMBOL_POINTERS = 0x06U,
65 /// S_LAZY_SYMBOL_POINTERS - Section with lazy symbol pointers.
66 S_LAZY_SYMBOL_POINTERS = 0x07U,
67 /// S_SYMBOL_STUBS - Section with symbol stubs, byte size of stub in
68 /// the Reserved2 field.
69 S_SYMBOL_STUBS = 0x08U,
70 /// S_MOD_INIT_FUNC_POINTERS - Section with only function pointers for
72 S_MOD_INIT_FUNC_POINTERS = 0x09U,
73 /// S_MOD_TERM_FUNC_POINTERS - Section with only function pointers for
75 S_MOD_TERM_FUNC_POINTERS = 0x0AU,
76 /// S_COALESCED - Section contains symbols that are to be coalesced.
78 /// S_GB_ZEROFILL - Zero fill on demand section (that can be larger than 4
80 S_GB_ZEROFILL = 0x0CU,
81 /// S_INTERPOSING - Section with only pairs of function pointers for
83 S_INTERPOSING = 0x0DU,
84 /// S_16BYTE_LITERALS - Section with only 16 byte literals.
85 S_16BYTE_LITERALS = 0x0EU,
86 /// S_DTRACE_DOF - Section contains DTrace Object Format.
88 /// S_LAZY_DYLIB_SYMBOL_POINTERS - Section with lazy symbol pointers to
89 /// lazy loaded dylibs.
90 S_LAZY_DYLIB_SYMBOL_POINTERS = 0x10U,
91 /// S_THREAD_LOCAL_REGULAR - Section with ....
92 S_THREAD_LOCAL_REGULAR = 0x11U,
93 /// S_THREAD_LOCAL_ZEROFILL - Thread local zerofill section.
94 S_THREAD_LOCAL_ZEROFILL = 0x12U,
95 /// S_THREAD_LOCAL_VARIABLES - Section with thread local variable structure
97 S_THREAD_LOCAL_VARIABLES = 0x13U,
98 /// S_THREAD_LOCAL_VARIABLE_POINTERS - Section with ....
99 S_THREAD_LOCAL_VARIABLE_POINTERS = 0x14U,
100 /// S_THREAD_LOCAL_INIT_FUNCTION_POINTERS - Section with thread local
101 /// variable initialization pointers to functions.
102 S_THREAD_LOCAL_INIT_FUNCTION_POINTERS = 0x15U,
104 LAST_KNOWN_SECTION_TYPE = S_THREAD_LOCAL_INIT_FUNCTION_POINTERS,
107 // Valid section attributes.
109 /// S_ATTR_PURE_INSTRUCTIONS - Section contains only true machine
111 S_ATTR_PURE_INSTRUCTIONS = 1U << 31,
112 /// S_ATTR_NO_TOC - Section contains coalesced symbols that are not to be
113 /// in a ranlib table of contents.
114 S_ATTR_NO_TOC = 1U << 30,
115 /// S_ATTR_STRIP_STATIC_SYMS - Ok to strip static symbols in this section
116 /// in files with the MY_DYLDLINK flag.
117 S_ATTR_STRIP_STATIC_SYMS = 1U << 29,
118 /// S_ATTR_NO_DEAD_STRIP - No dead stripping.
119 S_ATTR_NO_DEAD_STRIP = 1U << 28,
120 /// S_ATTR_LIVE_SUPPORT - Blocks are live if they reference live blocks.
121 S_ATTR_LIVE_SUPPORT = 1U << 27,
122 /// S_ATTR_SELF_MODIFYING_CODE - Used with i386 code stubs written on by
124 S_ATTR_SELF_MODIFYING_CODE = 1U << 26,
125 /// S_ATTR_DEBUG - A debug section.
126 S_ATTR_DEBUG = 1U << 25,
127 /// S_ATTR_SOME_INSTRUCTIONS - Section contains some machine instructions.
128 S_ATTR_SOME_INSTRUCTIONS = 1U << 10,
129 /// S_ATTR_EXT_RELOC - Section has external relocation entries.
130 S_ATTR_EXT_RELOC = 1U << 9,
131 /// S_ATTR_LOC_RELOC - Section has local relocation entries.
132 S_ATTR_LOC_RELOC = 1U << 8
135 StringRef getSegmentName() const {
136 // SegmentName is not necessarily null terminated!
138 return StringRef(SegmentName, 16);
139 return StringRef(SegmentName);
141 StringRef getSectionName() const {
142 // SectionName is not necessarily null terminated!
144 return StringRef(SectionName, 16);
145 return StringRef(SectionName);
148 virtual std::string getLabelBeginName() const {
149 return StringRef(getSegmentName().str() + getSectionName().str() + "_begin");
152 virtual std::string getLabelEndName() const {
153 return StringRef(getSegmentName().str() + getSectionName().str() + "_end");
156 unsigned getTypeAndAttributes() const { return TypeAndAttributes; }
157 unsigned getStubSize() const { return Reserved2; }
159 unsigned getType() const { return TypeAndAttributes & SECTION_TYPE; }
160 bool hasAttribute(unsigned Value) const {
161 return (TypeAndAttributes & Value) != 0;
164 /// ParseSectionSpecifier - Parse the section specifier indicated by "Spec".
165 /// This is a string that can appear after a .section directive in a mach-o
166 /// flavored .s file. If successful, this fills in the specified Out
167 /// parameters and returns an empty string. When an invalid section
168 /// specifier is present, this returns a string indicating the problem.
169 /// If no TAA was parsed, TAA is not altered, and TAAWasSet becomes false.
170 static std::string ParseSectionSpecifier(StringRef Spec, // In.
171 StringRef &Segment, // Out.
172 StringRef &Section, // Out.
173 unsigned &TAA, // Out.
174 bool &TAAParsed, // Out.
175 unsigned &StubSize); // Out.
177 virtual void PrintSwitchToSection(const MCAsmInfo &MAI,
179 const MCExpr *Subsection) const;
180 virtual bool UseCodeAlign() const;
181 virtual bool isVirtualSection() const;
183 static bool classof(const MCSection *S) {
184 return S->getVariant() == SV_MachO;
188 } // end namespace llvm