1 //===- MCSectionMachO.h - MachO Machine Code Sections -----------*- 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 declares the MCSectionMachO class. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_MC_MCSECTIONMACHO_H 15 #define LLVM_MC_MCSECTIONMACHO_H 16 17 #include "llvm/MC/MCSection.h" 18 19 namespace llvm { 20 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! 27 28 /// TypeAndAttributes - This is the SECTION_TYPE and SECTION_ATTRIBUTES 29 /// field of a section, drawn from the enums below. 30 unsigned TypeAndAttributes; 31 32 /// Reserved2 - The 'reserved2' field of a section, used to represent the 33 /// size of stubs, for example. 34 unsigned Reserved2; 35 36 MCSectionMachO(StringRef Segment, StringRef Section, 37 unsigned TAA, unsigned reserved2, SectionKind K); 38 friend class MCContext; 39 public: 40 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. 43 enum { 44 // TypeAndAttributes bitmasks. 45 SECTION_TYPE = 0x000000FFU, 46 SECTION_ATTRIBUTES = 0xFFFFFF00U, 47 48 // Valid section types. 49 50 /// S_REGULAR - Regular section. 51 S_REGULAR = 0x00U, 52 /// S_ZEROFILL - Zero fill on demand section. 53 S_ZEROFILL = 0x01U, 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_MOD_INIT_FUNC_POINTERS - Section with only function pointers for 70 /// initialization. 71 S_MOD_INIT_FUNC_POINTERS = 0x09U, 72 /// S_MOD_TERM_FUNC_POINTERS - Section with only function pointers for 73 /// termination. 74 S_MOD_TERM_FUNC_POINTERS = 0x0AU, 75 /// S_COALESCED - Section contains symbols that are to be coalesced. 76 S_COALESCED = 0x0BU, 77 /// S_GB_ZEROFILL - Zero fill on demand section (that can be larger than 4 78 /// gigabytes). 79 S_GB_ZEROFILL = 0x0CU, 80 /// S_INTERPOSING - Section with only pairs of function pointers for 81 /// interposing. 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. 86 S_DTRACE_DOF = 0x0FU, 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 95 /// data. 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, 102 103 LAST_KNOWN_SECTION_TYPE = S_THREAD_LOCAL_INIT_FUNCTION_POINTERS, 104 105 106 // Valid section attributes. 107 108 /// S_ATTR_PURE_INSTRUCTIONS - Section contains only true machine 109 /// instructions. 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 122 /// dyld. 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 << 8 132 }; 133 134 StringRef getSegmentName() const { 135 // SegmentName is not necessarily null terminated! 136 if (SegmentName[15]) 137 return StringRef(SegmentName, 16); 138 return StringRef(SegmentName); 139 } 140 StringRef getSectionName() const { 141 // SectionName is not necessarily null terminated! 142 if (SectionName[15]) 143 return StringRef(SectionName, 16); 144 return StringRef(SectionName); 145 } 146 147 unsigned getTypeAndAttributes() const { return TypeAndAttributes; } 148 unsigned getStubSize() const { return Reserved2; } 149 150 unsigned getType() const { return TypeAndAttributes & SECTION_TYPE; } 151 bool hasAttribute(unsigned Value) const { 152 return (TypeAndAttributes & Value) != 0; 153 } 154 155 /// 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 /// If no TAA was parsed, TAA is not altered, and TAAWasSet becomes false. 161 static std::string ParseSectionSpecifier(StringRef Spec, // In. 162 StringRef &Segment, // Out. 163 StringRef &Section, // Out. 164 unsigned &TAA, // Out. 165 bool &TAAParsed, // Out. 166 unsigned &StubSize); // Out. 167 168 virtual void PrintSwitchToSection(const MCAsmInfo &MAI, 169 raw_ostream &OS) const; 170 virtual bool UseCodeAlign() const; 171 virtual bool isVirtualSection() const; 172 173 static bool classof(const MCSection *S) { 174 return S->getVariant() == SV_MachO; 175 } 176 static bool classof(const MCSectionMachO *) { return true; } 177 }; 178 179 } // end namespace llvm 180 181 #endif 182
