1 //===-- llvm/CodeGen/DebugLocEntry.h - Entry in debug_loc list -*- C++ -*--===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DEBUGLOCENTRY_H
11 #define LLVM_LIB_CODEGEN_ASMPRINTER_DEBUGLOCENTRY_H
12 #include "llvm/ADT/SmallString.h"
13 #include "llvm/IR/Constants.h"
14 #include "llvm/IR/DebugInfo.h"
15 #include "llvm/MC/MCSymbol.h"
16 #include "llvm/MC/MachineLocation.h"
21 /// \brief This struct describes location entries emitted in the .debug_loc
24 /// Begin and end symbols for the address range that this location is valid.
25 const MCSymbol *Begin;
29 /// \brief A single location or constant.
31 Value(const MDNode *Var, const MDNode *Expr, int64_t i)
32 : Variable(Var), Expression(Expr), EntryKind(E_Integer) {
35 Value(const MDNode *Var, const MDNode *Expr, const ConstantFP *CFP)
36 : Variable(Var), Expression(Expr), EntryKind(E_ConstantFP) {
39 Value(const MDNode *Var, const MDNode *Expr, const ConstantInt *CIP)
40 : Variable(Var), Expression(Expr), EntryKind(E_ConstantInt) {
43 Value(const MDNode *Var, const MDNode *Expr, MachineLocation Loc)
44 : Variable(Var), Expression(Expr), EntryKind(E_Location), Loc(Loc) {
45 assert(isa<MDLocalVariable>(Var));
46 assert(cast<MDExpression>(Expr)->isValid());
49 /// The variable to which this location entry corresponds.
50 const MDNode *Variable;
52 /// Any complex address location expression for this Value.
53 const MDNode *Expression;
55 /// Type of entry that this represents.
56 enum EntryType { E_Location, E_Integer, E_ConstantFP, E_ConstantInt };
57 enum EntryType EntryKind;
59 /// Either a constant,
62 const ConstantFP *CFP;
63 const ConstantInt *CIP;
66 // Or a location in the machine frame.
69 bool isLocation() const { return EntryKind == E_Location; }
70 bool isInt() const { return EntryKind == E_Integer; }
71 bool isConstantFP() const { return EntryKind == E_ConstantFP; }
72 bool isConstantInt() const { return EntryKind == E_ConstantInt; }
73 int64_t getInt() const { return Constant.Int; }
74 const ConstantFP *getConstantFP() const { return Constant.CFP; }
75 const ConstantInt *getConstantInt() const { return Constant.CIP; }
76 MachineLocation getLoc() const { return Loc; }
77 DIVariable getVariable() const { return cast<MDLocalVariable>(Variable); }
78 bool isBitPiece() const { return getExpression()->isBitPiece(); }
79 DIExpression getExpression() const {
80 return cast_or_null<MDExpression>(Expression);
82 friend bool operator==(const Value &, const Value &);
83 friend bool operator<(const Value &, const Value &);
87 /// A nonempty list of locations/constants belonging to this entry,
89 SmallVector<Value, 1> Values;
90 SmallString<8> DWARFBytes;
91 SmallVector<std::string, 1> Comments;
94 DebugLocEntry(const MCSymbol *B, const MCSymbol *E, Value Val)
96 Values.push_back(std::move(Val));
99 /// \brief If this and Next are describing different pieces of the same
100 /// variable, merge them by appending Next's values to the current
102 /// Return true if the merge was successful.
103 bool MergeValues(const DebugLocEntry &Next) {
104 if (Begin == Next.Begin) {
105 DIExpression Expr = cast_or_null<MDExpression>(Values[0].Expression);
106 DIVariable Var = cast_or_null<MDLocalVariable>(Values[0].Variable);
107 DIExpression NextExpr =
108 cast_or_null<MDExpression>(Next.Values[0].Expression);
109 DIVariable NextVar = cast_or_null<MDLocalVariable>(Next.Values[0].Variable);
110 if (Var == NextVar && Expr->isBitPiece() && NextExpr->isBitPiece()) {
111 addValues(Next.Values);
119 /// \brief Attempt to merge this DebugLocEntry with Next and return
120 /// true if the merge was successful. Entries can be merged if they
121 /// share the same Loc/Constant and if Next immediately follows this
123 bool MergeRanges(const DebugLocEntry &Next) {
124 // If this and Next are describing the same variable, merge them.
125 if ((End == Next.Begin && Values == Next.Values)) {
132 const MCSymbol *getBeginSym() const { return Begin; }
133 const MCSymbol *getEndSym() const { return End; }
134 ArrayRef<Value> getValues() const { return Values; }
135 void addValues(ArrayRef<DebugLocEntry::Value> Vals) {
136 Values.append(Vals.begin(), Vals.end());
138 assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value V){
139 return V.isBitPiece();
140 }) && "value must be a piece");
143 // \brief Sort the pieces by offset.
144 // Remove any duplicate entries by dropping all but the first.
145 void sortUniqueValues() {
146 std::sort(Values.begin(), Values.end());
147 Values.erase(std::unique(Values.begin(), Values.end(),
148 [](const Value &A, const Value &B) {
149 return A.getVariable() == B.getVariable() &&
150 A.getExpression() == B.getExpression();
155 /// \brief Lower this entry into a DWARF expression.
156 void finalize(const AsmPrinter &AP,
157 const DITypeIdentifierMap &TypeIdentifierMap);
159 /// \brief Return the lowered DWARF expression.
160 StringRef getDWARFBytes() const { return DWARFBytes; }
161 /// \brief Return the assembler comments for the lowered DWARF expression.
162 const SmallVectorImpl<std::string> &getComments() const { return Comments; }
165 /// \brief Compare two Values for equality.
166 inline bool operator==(const DebugLocEntry::Value &A,
167 const DebugLocEntry::Value &B) {
168 if (A.EntryKind != B.EntryKind)
171 if (A.Expression != B.Expression)
174 if (A.Variable != B.Variable)
177 switch (A.EntryKind) {
178 case DebugLocEntry::Value::E_Location:
179 return A.Loc == B.Loc;
180 case DebugLocEntry::Value::E_Integer:
181 return A.Constant.Int == B.Constant.Int;
182 case DebugLocEntry::Value::E_ConstantFP:
183 return A.Constant.CFP == B.Constant.CFP;
184 case DebugLocEntry::Value::E_ConstantInt:
185 return A.Constant.CIP == B.Constant.CIP;
187 llvm_unreachable("unhandled EntryKind");
190 /// \brief Compare two pieces based on their offset.
191 inline bool operator<(const DebugLocEntry::Value &A,
192 const DebugLocEntry::Value &B) {
193 return A.getExpression()->getBitPieceOffset() <
194 B.getExpression()->getBitPieceOffset();