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Diffstat (limited to 'contrib/llvm/lib/CodeGen/AsmPrinter/DebugLocEntry.h')
-rw-r--r-- | contrib/llvm/lib/CodeGen/AsmPrinter/DebugLocEntry.h | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/contrib/llvm/lib/CodeGen/AsmPrinter/DebugLocEntry.h b/contrib/llvm/lib/CodeGen/AsmPrinter/DebugLocEntry.h new file mode 100644 index 0000000..083228b --- /dev/null +++ b/contrib/llvm/lib/CodeGen/AsmPrinter/DebugLocEntry.h @@ -0,0 +1,180 @@ +//===-- llvm/CodeGen/DebugLocEntry.h - Entry in debug_loc list -*- C++ -*--===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DEBUGLOCENTRY_H +#define LLVM_LIB_CODEGEN_ASMPRINTER_DEBUGLOCENTRY_H +#include "llvm/ADT/SmallString.h" +#include "llvm/IR/Constants.h" +#include "llvm/IR/DebugInfo.h" +#include "llvm/MC/MCSymbol.h" +#include "llvm/MC/MachineLocation.h" + +namespace llvm { +class AsmPrinter; +class DebugLocStream; + +/// \brief This struct describes location entries emitted in the .debug_loc +/// section. +class DebugLocEntry { + /// Begin and end symbols for the address range that this location is valid. + const MCSymbol *Begin; + const MCSymbol *End; + +public: + /// \brief A single location or constant. + struct Value { + Value(const DIExpression *Expr, int64_t i) + : Expression(Expr), EntryKind(E_Integer) { + Constant.Int = i; + } + Value(const DIExpression *Expr, const ConstantFP *CFP) + : Expression(Expr), EntryKind(E_ConstantFP) { + Constant.CFP = CFP; + } + Value(const DIExpression *Expr, const ConstantInt *CIP) + : Expression(Expr), EntryKind(E_ConstantInt) { + Constant.CIP = CIP; + } + Value(const DIExpression *Expr, MachineLocation Loc) + : Expression(Expr), EntryKind(E_Location), Loc(Loc) { + assert(cast<DIExpression>(Expr)->isValid()); + } + + /// Any complex address location expression for this Value. + const DIExpression *Expression; + + /// Type of entry that this represents. + enum EntryType { E_Location, E_Integer, E_ConstantFP, E_ConstantInt }; + enum EntryType EntryKind; + + /// Either a constant, + union { + int64_t Int; + const ConstantFP *CFP; + const ConstantInt *CIP; + } Constant; + + // Or a location in the machine frame. + MachineLocation Loc; + + bool isLocation() const { return EntryKind == E_Location; } + bool isInt() const { return EntryKind == E_Integer; } + bool isConstantFP() const { return EntryKind == E_ConstantFP; } + bool isConstantInt() const { return EntryKind == E_ConstantInt; } + int64_t getInt() const { return Constant.Int; } + const ConstantFP *getConstantFP() const { return Constant.CFP; } + const ConstantInt *getConstantInt() const { return Constant.CIP; } + MachineLocation getLoc() const { return Loc; } + bool isBitPiece() const { return getExpression()->isBitPiece(); } + const DIExpression *getExpression() const { return Expression; } + friend bool operator==(const Value &, const Value &); + friend bool operator<(const Value &, const Value &); + }; + +private: + /// A nonempty list of locations/constants belonging to this entry, + /// sorted by offset. + SmallVector<Value, 1> Values; + +public: + DebugLocEntry(const MCSymbol *B, const MCSymbol *E, Value Val) + : Begin(B), End(E) { + Values.push_back(std::move(Val)); + } + + /// \brief If this and Next are describing different pieces of the same + /// variable, merge them by appending Next's values to the current + /// list of values. + /// Return true if the merge was successful. + bool MergeValues(const DebugLocEntry &Next) { + if (Begin == Next.Begin) { + auto *Expr = cast_or_null<DIExpression>(Values[0].Expression); + auto *NextExpr = cast_or_null<DIExpression>(Next.Values[0].Expression); + if (Expr->isBitPiece() && NextExpr->isBitPiece()) { + addValues(Next.Values); + End = Next.End; + return true; + } + } + return false; + } + + /// \brief Attempt to merge this DebugLocEntry with Next and return + /// true if the merge was successful. Entries can be merged if they + /// share the same Loc/Constant and if Next immediately follows this + /// Entry. + bool MergeRanges(const DebugLocEntry &Next) { + // If this and Next are describing the same variable, merge them. + if ((End == Next.Begin && Values == Next.Values)) { + End = Next.End; + return true; + } + return false; + } + + const MCSymbol *getBeginSym() const { return Begin; } + const MCSymbol *getEndSym() const { return End; } + ArrayRef<Value> getValues() const { return Values; } + void addValues(ArrayRef<DebugLocEntry::Value> Vals) { + Values.append(Vals.begin(), Vals.end()); + sortUniqueValues(); + assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value V){ + return V.isBitPiece(); + }) && "value must be a piece"); + } + + // \brief Sort the pieces by offset. + // Remove any duplicate entries by dropping all but the first. + void sortUniqueValues() { + std::sort(Values.begin(), Values.end()); + Values.erase( + std::unique( + Values.begin(), Values.end(), [](const Value &A, const Value &B) { + return A.getExpression() == B.getExpression(); + }), + Values.end()); + } + + /// \brief Lower this entry into a DWARF expression. + void finalize(const AsmPrinter &AP, DebugLocStream &Locs, + const DIBasicType *BT); +}; + +/// \brief Compare two Values for equality. +inline bool operator==(const DebugLocEntry::Value &A, + const DebugLocEntry::Value &B) { + if (A.EntryKind != B.EntryKind) + return false; + + if (A.Expression != B.Expression) + return false; + + switch (A.EntryKind) { + case DebugLocEntry::Value::E_Location: + return A.Loc == B.Loc; + case DebugLocEntry::Value::E_Integer: + return A.Constant.Int == B.Constant.Int; + case DebugLocEntry::Value::E_ConstantFP: + return A.Constant.CFP == B.Constant.CFP; + case DebugLocEntry::Value::E_ConstantInt: + return A.Constant.CIP == B.Constant.CIP; + } + llvm_unreachable("unhandled EntryKind"); +} + +/// \brief Compare two pieces based on their offset. +inline bool operator<(const DebugLocEntry::Value &A, + const DebugLocEntry::Value &B) { + return A.getExpression()->getBitPieceOffset() < + B.getExpression()->getBitPieceOffset(); +} + +} // namespace llvm + +#endif |