//===-- llvm/Target/TargetLoweringObjectFile.h - Object Info ----*- C++ -*-===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file implements classes used to handle lowerings specific to common // object file formats. // //===----------------------------------------------------------------------===// #ifndef LLVM_MC_SECTIONKIND_H #define LLVM_MC_SECTIONKIND_H namespace llvm { /// SectionKind - This is a simple POD value that classifies the properties of /// a section. A section is classified into the deepest possible /// classification, and then the target maps them onto their sections based on /// what capabilities they have. /// /// The comments below describe these as if they were an inheritance hierarchy /// in order to explain the predicates below. /// class SectionKind { enum Kind { /// Metadata - Debug info sections or other metadata. Metadata, /// Text - Text section, used for functions and other executable code. Text, /// ReadOnly - Data that is never written to at program runtime by the /// program or the dynamic linker. Things in the top-level readonly /// SectionKind are not mergeable. ReadOnly, /// MergableCString - Any null-terminated string which allows merging. /// These values are known to end in a nul value of the specified size, /// not otherwise contain a nul value, and be mergable. This allows the /// linker to unique the strings if it so desires. /// Mergeable1ByteCString - 1 byte mergable, null terminated, string. Mergeable1ByteCString, /// Mergeable2ByteCString - 2 byte mergable, null terminated, string. Mergeable2ByteCString, /// Mergeable4ByteCString - 4 byte mergable, null terminated, string. Mergeable4ByteCString, /// MergeableConst - These are sections for merging fixed-length /// constants together. For example, this can be used to unique /// constant pool entries etc. MergeableConst, /// MergeableConst4 - This is a section used by 4-byte constants, /// for example, floats. MergeableConst4, /// MergeableConst8 - This is a section used by 8-byte constants, /// for example, doubles. MergeableConst8, /// MergeableConst16 - This is a section used by 16-byte constants, /// for example, vectors. MergeableConst16, /// Writeable - This is the base of all segments that need to be written /// to during program runtime. /// ThreadLocal - This is the base of all TLS segments. All TLS /// objects must be writeable, otherwise there is no reason for them to /// be thread local! /// ThreadBSS - Zero-initialized TLS data objects. ThreadBSS, /// ThreadData - Initialized TLS data objects. ThreadData, /// GlobalWriteableData - Writeable data that is global (not thread /// local). /// BSS - Zero initialized writeable data. BSS, /// BSSLocal - This is BSS (zero initialized and writable) data /// which has local linkage. BSSLocal, /// BSSExtern - This is BSS data with normal external linkage. BSSExtern, /// Common - Data with common linkage. These represent tentative /// definitions, which always have a zero initializer and are never /// marked 'constant'. Common, /// DataRel - This is the most general form of data that is written /// to by the program, it can have random relocations to arbitrary /// globals. DataRel, /// DataRelLocal - This is writeable data that has a non-zero /// initializer and has relocations in it, but all of the /// relocations are known to be within the final linked image /// the global is linked into. DataRelLocal, /// DataNoRel - This is writeable data that has a non-zero /// initializer, but whose initializer is known to have no /// relocations. DataNoRel, /// ReadOnlyWithRel - These are global variables that are never /// written to by the program, but that have relocations, so they /// must be stuck in a writeable section so that the dynamic linker /// can write to them. If it chooses to, the dynamic linker can /// mark the pages these globals end up on as read-only after it is /// done with its relocation phase. ReadOnlyWithRel, /// ReadOnlyWithRelLocal - This is data that is readonly by the /// program, but must be writeable so that the dynamic linker /// can perform relocations in it. This is used when we know /// that all the relocations are to globals in this final /// linked image. ReadOnlyWithRelLocal } K : 8; public: bool isMetadata() const { return K == Metadata; } bool isText() const { return K == Text; } bool isReadOnly() const { return K == ReadOnly || isMergeableCString() || isMergeableConst(); } bool isMergeableCString() const { return K == Mergeable1ByteCString || K == Mergeable2ByteCString || K == Mergeable4ByteCString; } bool isMergeable1ByteCString() const { return K == Mergeable1ByteCString; } bool isMergeable2ByteCString() const { return K == Mergeable2ByteCString; } bool isMergeable4ByteCString() const { return K == Mergeable4ByteCString; } bool isMergeableConst() const { return K == MergeableConst || K == MergeableConst4 || K == MergeableConst8 || K == MergeableConst16; } bool isMergeableConst4() const { return K == MergeableConst4; } bool isMergeableConst8() const { return K == MergeableConst8; } bool isMergeableConst16() const { return K == MergeableConst16; } bool isWriteable() const { return isThreadLocal() || isGlobalWriteableData(); } bool isThreadLocal() const { return K == ThreadData || K == ThreadBSS; } bool isThreadBSS() const { return K == ThreadBSS; } bool isThreadData() const { return K == ThreadData; } bool isGlobalWriteableData() const { return isBSS() || isCommon() || isDataRel() || isReadOnlyWithRel(); } bool isBSS() const { return K == BSS || K == BSSLocal || K == BSSExtern; } bool isBSSLocal() const { return K == BSSLocal; } bool isBSSExtern() const { return K == BSSExtern; } bool isCommon() const { return K == Common; } bool isDataRel() const { return K == DataRel || K == DataRelLocal || K == DataNoRel; } bool isDataRelLocal() const { return K == DataRelLocal || K == DataNoRel; } bool isDataNoRel() const { return K == DataNoRel; } bool isReadOnlyWithRel() const { return K == ReadOnlyWithRel || K == ReadOnlyWithRelLocal; } bool isReadOnlyWithRelLocal() const { return K == ReadOnlyWithRelLocal; } private: static SectionKind get(Kind K) { SectionKind Res; Res.K = K; return Res; } public: static SectionKind getMetadata() { return get(Metadata); } static SectionKind getText() { return get(Text); } static SectionKind getReadOnly() { return get(ReadOnly); } static SectionKind getMergeable1ByteCString() { return get(Mergeable1ByteCString); } static SectionKind getMergeable2ByteCString() { return get(Mergeable2ByteCString); } static SectionKind getMergeable4ByteCString() { return get(Mergeable4ByteCString); } static SectionKind getMergeableConst() { return get(MergeableConst); } static SectionKind getMergeableConst4() { return get(MergeableConst4); } static SectionKind getMergeableConst8() { return get(MergeableConst8); } static SectionKind getMergeableConst16() { return get(MergeableConst16); } static SectionKind getThreadBSS() { return get(ThreadBSS); } static SectionKind getThreadData() { return get(ThreadData); } static SectionKind getBSS() { return get(BSS); } static SectionKind getBSSLocal() { return get(BSSLocal); } static SectionKind getBSSExtern() { return get(BSSExtern); } static SectionKind getCommon() { return get(Common); } static SectionKind getDataRel() { return get(DataRel); } static SectionKind getDataRelLocal() { return get(DataRelLocal); } static SectionKind getDataNoRel() { return get(DataNoRel); } static SectionKind getReadOnlyWithRel() { return get(ReadOnlyWithRel); } static SectionKind getReadOnlyWithRelLocal(){ return get(ReadOnlyWithRelLocal); } }; } // end namespace llvm #endif