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/ADT/StringRef.h" 18 #include "llvm/MC/MCSection.h" 19 #include "llvm/Support/MachO.h" 20 21 namespace llvm { 22 23 /// MCSectionMachO - This represents a section on a Mach-O system (used by 24 /// Mac OS X). On a Mac system, these are also described in 25 /// /usr/include/mach-o/loader.h. 26 class MCSectionMachO : public MCSection { 27 char SegmentName[16]; // Not necessarily null terminated! 28 char SectionName[16]; // Not necessarily null terminated! 29 30 /// TypeAndAttributes - This is the SECTION_TYPE and SECTION_ATTRIBUTES 31 /// field of a section, drawn from the enums below. 32 unsigned TypeAndAttributes; 33 34 /// Reserved2 - The 'reserved2' field of a section, used to represent the 35 /// size of stubs, for example. 36 unsigned Reserved2; 37 38 MCSectionMachO(StringRef Segment, StringRef Section, 39 unsigned TAA, unsigned reserved2, SectionKind K); 40 friend class MCContext; 41 public: 42 43 StringRef getSegmentName() const { 44 // SegmentName is not necessarily null terminated! 45 if (SegmentName[15]) 46 return StringRef(SegmentName, 16); 47 return StringRef(SegmentName); 48 } 49 StringRef getSectionName() const { 50 // SectionName is not necessarily null terminated! 51 if (SectionName[15]) 52 return StringRef(SectionName, 16); 53 return StringRef(SectionName); 54 } 55 56 std::string getLabelBeginName() const override { 57 return StringRef(getSegmentName().str() + getSectionName().str() + "_begin"); 58 } 59 60 std::string getLabelEndName() const override { 61 return StringRef(getSegmentName().str() + getSectionName().str() + "_end"); 62 } 63 64 unsigned getTypeAndAttributes() const { return TypeAndAttributes; } 65 unsigned getStubSize() const { return Reserved2; } 66 67 MachO::SectionType getType() const { 68 return static_cast<MachO::SectionType>(TypeAndAttributes & 69 MachO::SECTION_TYPE); 70 } 71 bool hasAttribute(unsigned Value) const { 72 return (TypeAndAttributes & Value) != 0; 73 } 74 75 /// ParseSectionSpecifier - Parse the section specifier indicated by "Spec". 76 /// This is a string that can appear after a .section directive in a mach-o 77 /// flavored .s file. If successful, this fills in the specified Out 78 /// parameters and returns an empty string. When an invalid section 79 /// specifier is present, this returns a string indicating the problem. 80 /// If no TAA was parsed, TAA is not altered, and TAAWasSet becomes false. 81 static std::string ParseSectionSpecifier(StringRef Spec, // In. 82 StringRef &Segment, // Out. 83 StringRef &Section, // Out. 84 unsigned &TAA, // Out. 85 bool &TAAParsed, // Out. 86 unsigned &StubSize); // Out. 87 88 void PrintSwitchToSection(const MCAsmInfo &MAI, raw_ostream &OS, 89 const MCExpr *Subsection) const override; 90 bool UseCodeAlign() const override; 91 bool isVirtualSection() const override; 92 93 static bool classof(const MCSection *S) { 94 return S->getVariant() == SV_MachO; 95 } 96 }; 97 98 } // end namespace llvm 99 100 #endif 101
