-/// SectionKind - This is a simple POD value that classifies the properties of
-/// a section. A global variable 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 {
-public:
- 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,
-
- /// MergeableCString - This is a special section for nul-terminated
- /// strings. The linker can unique the C strings, knowing their
- /// semantics. Because it uniques based on the nul terminators, the
- /// compiler can't put strings in this section that have embeded nuls
- /// in them.
- MergeableCString,
-
- /// 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,
-
- /// 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
-
- };
-
-private:
- Kind K : 6;
-
- /// Weak - This is true if the referenced symbol is weak (i.e. linkonce,
- /// weak, weak_odr, etc). This is orthogonal from the categorization.
- bool Weak : 1;
-
- /// ExplicitSection - This is true if the global had a section explicitly
- /// specified on it.
- bool ExplicitSection : 1;
-public:
-
- // FIXME: REMOVE.
- Kind getKind() const { return K; }
-
- bool isWeak() const { return Weak; }
- bool hasExplicitSection() const { return ExplicitSection; }
-
-
- bool isMetadata() const { return K == Metadata; }
- bool isText() const { return K == Text; }
-
- bool isReadOnly() const {
- return K == ReadOnly || K == MergeableCString || isMergeableConst();
- }
-
- bool isMergeableCString() const { return K == MergeableCString; }
- 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() || isDataRel() || isReadOnlyWithRel();
- }
-
- bool isBSS() const { return K == BSS; }
-
- 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;
- }
-
- static SectionKind get(Kind K, bool isWeak = false,
- bool hasExplicitSection = false) {
- SectionKind Res;
- Res.K = K;
- Res.Weak = isWeak;
- Res.ExplicitSection = hasExplicitSection;
- return Res;
- }
-};
-
-
-class TargetLoweringObjectFile {