llvm-project/llvm/lib/CodeGen/AsmPrinter/DebugLocEntry.h

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//===-- 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 CODEGEN_ASMPRINTER_DEBUGLOCENTRY_H__
#define CODEGEN_ASMPRINTER_DEBUGLOCENTRY_H__
#include "llvm/IR/Constants.h"
#include "llvm/IR/DebugInfo.h"
#include "llvm/MC/MachineLocation.h"
#include "llvm/MC/MCSymbol.h"
namespace llvm {
class MDNode;
/// \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:
/// A single location or constant.
struct Value {
Value(const MDNode *Var, int64_t i)
: Variable(Var), EntryKind(E_Integer) {
Constant.Int = i;
}
Value(const MDNode *Var, const ConstantFP *CFP)
: Variable(Var), EntryKind(E_ConstantFP) {
Constant.CFP = CFP;
}
Value(const MDNode *Var, const ConstantInt *CIP)
: Variable(Var), EntryKind(E_ConstantInt) {
Constant.CIP = CIP;
}
Value(const MDNode *Var, MachineLocation Loc)
: Variable(Var), EntryKind(E_Location), Loc(Loc) {
}
// The variable to which this location entry corresponds.
const MDNode *Variable;
// 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; }
const MDNode *getVariableNode() const { return Variable; }
DIVariable getVariable() const { return DIVariable(Variable); }
bool isVariablePiece() const { return getVariable().isVariablePiece(); }
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 && Values.size() > 0 && Next.Values.size() > 0) {
DIVariable Var(Values[0].Variable);
DIVariable NextVar(Next.Values[0].Variable);
if (Var.getName() == NextVar.getName() &&
Var.isVariablePiece() && NextVar.isVariablePiece()) {
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; }
const 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.isVariablePiece();
}) && "value must be a piece");
}
// 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.getVariable() == B.getVariable();
}), Values.end());
}
};
/// 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.getVariable() != B.getVariable())
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");
}
/// Compare two pieces based on their offset.
inline bool operator<(const DebugLocEntry::Value &A,
const DebugLocEntry::Value &B) {
return A.getVariable().getPieceOffset() < B.getVariable().getPieceOffset();
}
}
#endif