e90c43e9dd699978024493e6581447153bc619a6
1 //===-- llvm/CodeGen/DebugLocEntry.h - Entry in debug_loc list -*- C++ -*--===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
10 #ifndef CODEGEN_ASMPRINTER_DEBUGLOCENTRY_H__
11 #define CODEGEN_ASMPRINTER_DEBUGLOCENTRY_H__
12 #include "llvm/IR/Constants.h"
13 #include "llvm/IR/DebugInfo.h"
14 #include "llvm/MC/MachineLocation.h"
15 #include "llvm/MC/MCSymbol.h"
17 namespace llvm {
18 class MDNode;
19 /// \brief This struct describes location entries emitted in the .debug_loc
20 /// section.
21 class DebugLocEntry {
22 // Begin and end symbols for the address range that this location is valid.
23 const MCSymbol *Begin;
24 const MCSymbol *End;
26 public:
27 /// A single location or constant.
28 struct Value {
29 Value(const MDNode *Var, int64_t i)
30 : Variable(Var), EntryKind(E_Integer) {
31 Constant.Int = i;
32 }
33 Value(const MDNode *Var, const ConstantFP *CFP)
34 : Variable(Var), EntryKind(E_ConstantFP) {
35 Constant.CFP = CFP;
36 }
37 Value(const MDNode *Var, const ConstantInt *CIP)
38 : Variable(Var), EntryKind(E_ConstantInt) {
39 Constant.CIP = CIP;
40 }
41 Value(const MDNode *Var, MachineLocation Loc)
42 : Variable(Var), EntryKind(E_Location), Loc(Loc) {
43 }
45 // The variable to which this location entry corresponds.
46 const MDNode *Variable;
48 // Type of entry that this represents.
49 enum EntryType { E_Location, E_Integer, E_ConstantFP, E_ConstantInt };
50 enum EntryType EntryKind;
52 // Either a constant,
53 union {
54 int64_t Int;
55 const ConstantFP *CFP;
56 const ConstantInt *CIP;
57 } Constant;
59 // Or a location in the machine frame.
60 MachineLocation Loc;
62 bool operator==(const Value &other) const {
63 if (EntryKind != other.EntryKind)
64 return false;
66 switch (EntryKind) {
67 case E_Location:
68 return Loc == other.Loc;
69 case E_Integer:
70 return Constant.Int == other.Constant.Int;
71 case E_ConstantFP:
72 return Constant.CFP == other.Constant.CFP;
73 case E_ConstantInt:
74 return Constant.CIP == other.Constant.CIP;
75 }
76 llvm_unreachable("unhandled EntryKind");
77 }
79 // Compare two pieces based on their offset.
80 bool operator<(const Value &other) const {
81 DIVariable Var(Variable);
82 DIVariable OtherVar(other.Variable);
83 return Var.getPieceOffset() < OtherVar.getPieceOffset();
84 }
86 bool isLocation() const { return EntryKind == E_Location; }
87 bool isInt() const { return EntryKind == E_Integer; }
88 bool isConstantFP() const { return EntryKind == E_ConstantFP; }
89 bool isConstantInt() const { return EntryKind == E_ConstantInt; }
90 int64_t getInt() const { return Constant.Int; }
91 const ConstantFP *getConstantFP() const { return Constant.CFP; }
92 const ConstantInt *getConstantInt() const { return Constant.CIP; }
93 MachineLocation getLoc() const { return Loc; }
94 const MDNode *getVariable() const { return Variable; }
95 };
96 private:
97 /// A nonempty list of locations/constants belonging to this entry,
98 /// sorted by offset.
99 SmallVector<Value, 1> Values;
101 public:
102 DebugLocEntry(const MCSymbol *B, const MCSymbol *E, Value Val)
103 : Begin(B), End(E) {
104 Values.push_back(std::move(Val));
105 }
107 /// \brief If this and Next are describing different pieces of the same
108 // variable, merge them by appending Next's values to the current
109 // list of values.
110 // Return true if the merge was successful.
111 bool MergeValues(const DebugLocEntry &Next) {
112 if (Begin == Next.Begin && Values.size() > 0 && Next.Values.size() > 0) {
113 DIVariable Var(Values[0].Variable);
114 DIVariable NextVar(Next.Values[0].Variable);
115 if (Var.getName() == NextVar.getName() &&
116 Var.isVariablePiece() && NextVar.isVariablePiece()) {
117 addValues(Next.Values);
118 End = Next.End;
119 return true;
120 }
121 }
122 return false;
123 }
125 /// \brief Attempt to merge this DebugLocEntry with Next and return
126 /// true if the merge was successful. Entries can be merged if they
127 /// share the same Loc/Constant and if Next immediately follows this
128 /// Entry.
129 bool MergeRanges(const DebugLocEntry &Next) {
130 // If this and Next are describing the same variable, merge them.
131 if ((End == Next.Begin && Values == Next.Values)) {
132 End = Next.End;
133 return true;
134 }
135 return false;
136 }
138 const MCSymbol *getBeginSym() const { return Begin; }
139 const MCSymbol *getEndSym() const { return End; }
140 const ArrayRef<Value> getValues() const { return Values; }
141 void addValues(ArrayRef<DebugLocEntry::Value> Vals) {
142 Values.append(Vals.begin(), Vals.end());
143 sortUniqueValues();
144 assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value V){
145 return DIVariable(V.Variable).isVariablePiece();
146 }) && "value must be a piece");
147 }
149 // Sort the pieces by offset.
150 // Remove any duplicate entries by dropping all but the first.
151 void sortUniqueValues() {
152 std::sort(Values.begin(), Values.end());
153 Values.erase(std::unique(Values.begin(), Values.end()), Values.end());
154 }
155 };
157 }
158 #endif