#ifndef LLVM_MC_MCSYMBOL_H
#define LLVM_MC_MCSYMBOL_H
-#include <string>
#include "llvm/ADT/StringRef.h"
namespace llvm {
+ class MCExpr;
class MCSection;
class MCContext;
class raw_ostream;
/// MCSymbol - Instances of this class represent a symbol name in the MC file,
- /// and MCSymbols are created and unique'd by the MCContext class.
+ /// and MCSymbols are created and unique'd by the MCContext class. MCSymbols
+ /// should only be constructed with valid names for the object file.
///
/// If the symbol is defined/emitted into the current translation unit, the
/// Section member is set to indicate what section it lives in. Otherwise, if
- /// it is a reference to an external entity, it has a null section.
- ///
+ /// it is a reference to an external entity, it has a null section.
class MCSymbol {
- /// Name - The name of the symbol.
- std::string Name;
- /// Section - The section the symbol is defined in, or null if the symbol
- /// has not been defined in the associated translation unit.
+ // Special sentinal value for the absolute pseudo section.
+ //
+ // FIXME: Use a PointerInt wrapper for this?
+ static const MCSection *AbsolutePseudoSection;
+
+ /// Name - The name of the symbol. The referred-to string data is actually
+ /// held by the StringMap that lives in MCContext.
+ StringRef Name;
+
+ /// Section - The section the symbol is defined in. This is null for
+ /// undefined symbols, and the special AbsolutePseudoSection value for
+ /// absolute symbols.
const MCSection *Section;
-
+
+ /// Value - If non-null, the value for a variable symbol.
+ const MCExpr *Value;
+
/// IsTemporary - True if this is an assembler temporary label, which
/// typically does not survive in the .o file's symbol table. Usually
/// "Lfoo" or ".foo".
unsigned IsTemporary : 1;
-
- /// IsExternal - True if this symbol has been implicitly defined as an
- /// external, for example by using it in an expression without ever emitting
- /// it as a label. The @var Section for an external symbol is always null.
- unsigned IsExternal : 1;
+
+ /// IsUsed - True if this symbol has been used.
+ mutable unsigned IsUsed : 1;
private: // MCContext creates and uniques these.
friend class MCContext;
- MCSymbol(const StringRef &_Name, bool _IsTemporary)
- : Name(_Name), Section(0), IsTemporary(_IsTemporary), IsExternal(false) {}
-
+ MCSymbol(StringRef name, bool isTemporary)
+ : Name(name), Section(0), Value(0),
+ IsTemporary(isTemporary), IsUsed(false) {}
+
MCSymbol(const MCSymbol&); // DO NOT IMPLEMENT
void operator=(const MCSymbol&); // DO NOT IMPLEMENT
public:
-
- const MCSection *getSection() const { return Section; }
- void setSection(const MCSection *S) { Section = S; }
+ /// getName - Get the symbol name.
+ StringRef getName() const { return Name; }
+
+ /// @name Accessors
+ /// @{
+
+ /// isTemporary - Check if this is an assembler temporary symbol.
+ bool isTemporary() const { return IsTemporary; }
+
+ /// isUsed - Check if this is used.
+ bool isUsed() const { return IsUsed; }
+ void setUsed(bool Value) const { IsUsed = Value; }
+
+ /// @}
+ /// @name Associated Sections
+ /// @{
+
+ /// isDefined - Check if this symbol is defined (i.e., it has an address).
+ ///
+ /// Defined symbols are either absolute or in some section.
+ bool isDefined() const {
+ return Section != 0;
+ }
+
+ /// isInSection - Check if this symbol is defined in some section (i.e., it
+ /// is defined but not absolute).
+ bool isInSection() const {
+ return isDefined() && !isAbsolute();
+ }
+
+ /// isUndefined - Check if this symbol undefined (i.e., implicitly defined).
+ bool isUndefined() const {
+ return !isDefined();
+ }
+
+ /// isAbsolute - Check if this is an absolute symbol.
+ bool isAbsolute() const {
+ return Section == AbsolutePseudoSection;
+ }
+
+ /// getSection - Get the section associated with a defined, non-absolute
+ /// symbol.
+ const MCSection &getSection() const {
+ assert(isInSection() && "Invalid accessor!");
+ return *Section;
+ }
+
+ /// setSection - Mark the symbol as defined in the section \arg S.
+ void setSection(const MCSection &S) { Section = &S; }
+
+ /// setUndefined - Mark the symbol as undefined.
+ void setUndefined() {
+ Section = 0;
+ }
+
+ /// setAbsolute - Mark the symbol as absolute.
+ void setAbsolute() { Section = AbsolutePseudoSection; }
+
+ /// @}
+ /// @name Variable Symbols
+ /// @{
+
+ /// isVariable - Check if this is a variable symbol.
+ bool isVariable() const {
+ return Value != 0;
+ }
+
+ /// getValue() - Get the value for variable symbols.
+ const MCExpr *getVariableValue() const {
+ assert(isVariable() && "Invalid accessor!");
+ IsUsed = true;
+ return Value;
+ }
+
+ // AliasedSymbol() - If this is an alias (a = b), return the symbol
+ // we ultimately point to. For a non alias, this just returns the symbol
+ // itself.
+ const MCSymbol &AliasedSymbol() const;
- bool isExternal() const { return IsExternal; }
- void setExternal(bool Value) { IsExternal = Value; }
+ void setVariableValue(const MCExpr *Value);
- const std::string &getName() const { return Name; }
+ /// @}
/// print - Print the value to the stream \arg OS.
void print(raw_ostream &OS) const;
void dump() const;
};
+ inline raw_ostream &operator<<(raw_ostream &OS, const MCSymbol &Sym) {
+ Sym.print(OS);
+ return OS;
+ }
} // end namespace llvm
#endif
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