LLVM  9.0.0svn
DebugLocEntry.h
Go to the documentation of this file.
1 //===-- llvm/CodeGen/DebugLocEntry.h - Entry in debug_loc list -*- C++ -*--===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DEBUGLOCENTRY_H
10 #define LLVM_LIB_CODEGEN_ASMPRINTER_DEBUGLOCENTRY_H
11 
12 #include "DebugLocStream.h"
13 #include "llvm/Config/llvm-config.h"
14 #include "llvm/IR/Constants.h"
15 #include "llvm/IR/DebugInfo.h"
16 #include "llvm/MC/MCSymbol.h"
18 #include "llvm/Support/Debug.h"
19 
20 namespace llvm {
21 class AsmPrinter;
22 
23 /// This struct describes location entries emitted in the .debug_loc
24 /// section.
26  /// Begin and end symbols for the address range that this location is valid.
27  const MCSymbol *Begin;
28  const MCSymbol *End;
29 
30 public:
31  /// A single location or constant.
32  struct Value {
33  Value(const DIExpression *Expr, int64_t i)
34  : Expression(Expr), EntryKind(E_Integer) {
35  Constant.Int = i;
36  }
37  Value(const DIExpression *Expr, const ConstantFP *CFP)
39  Constant.CFP = CFP;
40  }
41  Value(const DIExpression *Expr, const ConstantInt *CIP)
43  Constant.CIP = CIP;
44  }
46  : Expression(Expr), EntryKind(E_Location), Loc(Loc) {
47  assert(cast<DIExpression>(Expr)->isValid());
48  }
49 
50  /// Any complex address location expression for this Value.
52 
53  /// Type of entry that this represents.
56 
57  /// Either a constant,
58  union {
59  int64_t Int;
60  const ConstantFP *CFP;
61  const ConstantInt *CIP;
62  } Constant;
63 
64  // Or a location in the machine frame.
66 
67  bool isLocation() const { return EntryKind == E_Location; }
68  bool isInt() const { return EntryKind == E_Integer; }
69  bool isConstantFP() const { return EntryKind == E_ConstantFP; }
70  bool isConstantInt() const { return EntryKind == E_ConstantInt; }
71  int64_t getInt() const { return Constant.Int; }
72  const ConstantFP *getConstantFP() const { return Constant.CFP; }
73  const ConstantInt *getConstantInt() const { return Constant.CIP; }
74  MachineLocation getLoc() const { return Loc; }
75  bool isFragment() const { return getExpression()->isFragment(); }
76  const DIExpression *getExpression() const { return Expression; }
77  friend bool operator==(const Value &, const Value &);
78  friend bool operator<(const Value &, const Value &);
79 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
80  LLVM_DUMP_METHOD void dump() const {
81  if (isLocation()) {
82  llvm::dbgs() << "Loc = { reg=" << Loc.getReg() << " ";
83  if (Loc.isIndirect())
84  llvm::dbgs() << "+0";
85  llvm::dbgs() << "} ";
86  }
87  else if (isConstantInt())
88  Constant.CIP->dump();
89  else if (isConstantFP())
90  Constant.CFP->dump();
91  if (Expression)
92  Expression->dump();
93  }
94 #endif
95  };
96 
97 private:
98  /// A nonempty list of locations/constants belonging to this entry,
99  /// sorted by offset.
100  SmallVector<Value, 1> Values;
101 
102 public:
103  /// Create a location list entry for the range [\p Begin, \p End).
104  ///
105  /// \param Vals One or more values describing (parts of) the variable.
106  DebugLocEntry(const MCSymbol *Begin, const MCSymbol *End,
107  ArrayRef<Value> Vals)
108  : Begin(Begin), End(End) {
109  addValues(Vals);
110  }
111 
112  /// Attempt to merge this DebugLocEntry with Next and return
113  /// true if the merge was successful. Entries can be merged if they
114  /// share the same Loc/Constant and if Next immediately follows this
115  /// Entry.
116  bool MergeRanges(const DebugLocEntry &Next) {
117  // If this and Next are describing the same variable, merge them.
118  if ((End == Next.Begin && Values == Next.Values)) {
119  End = Next.End;
120  return true;
121  }
122  return false;
123  }
124 
125  const MCSymbol *getBeginSym() const { return Begin; }
126  const MCSymbol *getEndSym() const { return End; }
127  ArrayRef<Value> getValues() const { return Values; }
129  Values.append(Vals.begin(), Vals.end());
131  assert((Values.size() == 1 ||
132  all_of(Values,
133  [](DebugLocEntry::Value V) { return V.isFragment(); })) &&
134  "must either have a single value or multiple pieces");
135  }
136 
137  // Sort the pieces by offset.
138  // Remove any duplicate entries by dropping all but the first.
140  llvm::sort(Values);
141  Values.erase(
142  std::unique(
143  Values.begin(), Values.end(), [](const Value &A, const Value &B) {
144  return A.getExpression() == B.getExpression();
145  }),
146  Values.end());
147  }
148 
149  /// Lower this entry into a DWARF expression.
150  void finalize(const AsmPrinter &AP,
152  const DIBasicType *BT,
153  DwarfCompileUnit &TheCU);
154 };
155 
156 /// Compare two Values for equality.
157 inline bool operator==(const DebugLocEntry::Value &A,
158  const DebugLocEntry::Value &B) {
159  if (A.EntryKind != B.EntryKind)
160  return false;
161 
162  if (A.Expression != B.Expression)
163  return false;
164 
165  switch (A.EntryKind) {
167  return A.Loc == B.Loc;
169  return A.Constant.Int == B.Constant.Int;
171  return A.Constant.CFP == B.Constant.CFP;
173  return A.Constant.CIP == B.Constant.CIP;
174  }
175  llvm_unreachable("unhandled EntryKind");
176 }
177 
178 /// Compare two fragments based on their offset.
179 inline bool operator<(const DebugLocEntry::Value &A,
180  const DebugLocEntry::Value &B) {
181  return A.getExpression()->getFragmentInfo()->OffsetInBits <
182  B.getExpression()->getFragmentInfo()->OffsetInBits;
183 }
184 
185 }
186 
187 #endif
bool MergeRanges(const DebugLocEntry &Next)
Attempt to merge this DebugLocEntry with Next and return true if the merge was successful.
ArrayRef< Value > getValues() const
Builder for DebugLocStream lists.
friend bool operator==(const Value &, const Value &)
Compare two Values for equality.
This struct describes location entries emitted in the .debug_loc section.
Definition: DebugLocEntry.h:25
This class represents lattice values for constants.
Definition: AllocatorList.h:23
#define LLVM_DUMP_METHOD
Mark debug helper function definitions like dump() that should not be stripped from debug builds...
Definition: Compiler.h:473
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:41
iterator begin() const
Definition: ArrayRef.h:136
unsigned getReg() const
Value(const DIExpression *Expr, int64_t i)
Definition: DebugLocEntry.h:33
const DIExpression * Expression
Any complex address location expression for this Value.
Definition: DebugLocEntry.h:51
Value(const DIExpression *Expr, const ConstantFP *CFP)
Definition: DebugLocEntry.h:37
bool all_of(R &&range, UnaryPredicate P)
Provide wrappers to std::all_of which take ranges instead of having to pass begin/end explicitly...
Definition: STLExtras.h:1185
EntryType
Type of entry that this represents.
Definition: DebugLocEntry.h:54
const ConstantFP * CFP
Definition: DebugLocEntry.h:60
void dump() const
Support for debugging, callable in GDB: V->dump()
Definition: AsmWriter.cpp:4362
const MCSymbol * getBeginSym() const
Value(const DIExpression *Expr, const ConstantInt *CIP)
Definition: DebugLocEntry.h:41
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory)...
Definition: APInt.h:32
static Optional< FragmentInfo > getFragmentInfo(expr_op_iterator Start, expr_op_iterator End)
Retrieve the details of this fragment expression.
Value(const DIExpression *Expr, MachineLocation Loc)
Definition: DebugLocEntry.h:45
friend bool operator<(const Value &, const Value &)
Compare two fragments based on their offset.
static GCRegistry::Add< OcamlGC > B("ocaml", "ocaml 3.10-compatible GC")
This is an important base class in LLVM.
Definition: Constant.h:41
const DIExpression * getExpression() const
Definition: DebugLocEntry.h:76
This file contains the declarations for the subclasses of Constant, which represent the different fla...
ConstantFP - Floating Point Values [float, double].
Definition: Constants.h:263
This class is intended to be used as a driving class for all asm writers.
Definition: AsmPrinter.h:78
const ConstantInt * getConstantInt() const
Definition: DebugLocEntry.h:73
LLVM_DUMP_METHOD void dump() const
Definition: DebugLocEntry.h:80
const ConstantInt * CIP
Definition: DebugLocEntry.h:61
iterator erase(const_iterator CI)
Definition: SmallVector.h:438
size_t size() const
Definition: SmallVector.h:52
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
void sort(IteratorTy Start, IteratorTy End)
Definition: STLExtras.h:1115
This is the shared class of boolean and integer constants.
Definition: Constants.h:83
union llvm::DebugLocEntry::Value::@344 Constant
Either a constant,.
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:841
iterator end() const
Definition: ArrayRef.h:137
const MCSymbol * getEndSym() const
void finalize(const AsmPrinter &AP, DebugLocStream::ListBuilder &List, const DIBasicType *BT, DwarfCompileUnit &TheCU)
Lower this entry into a DWARF expression.
DWARF expression.
raw_ostream & dbgs()
dbgs() - This returns a reference to a raw_ostream for debugging messages.
Definition: Debug.cpp:132
void append(in_iter in_start, in_iter in_end)
Add the specified range to the end of the SmallVector.
Definition: SmallVector.h:387
A single location or constant.
Definition: DebugLocEntry.h:32
const NodeList & List
Definition: RDFGraph.cpp:201
void dump() const
User-friendly dump.
Definition: AsmWriter.cpp:4384
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
DebugLocEntry(const MCSymbol *Begin, const MCSymbol *End, ArrayRef< Value > Vals)
Create a location list entry for the range [Begin, End).
MachineLocation getLoc() const
Definition: DebugLocEntry.h:74
bool isFragment() const
Return whether this is a piece of an aggregate variable.
void addValues(ArrayRef< DebugLocEntry::Value > Vals)
const ConstantFP * getConstantFP() const
Definition: DebugLocEntry.h:72
Basic type, like &#39;int&#39; or &#39;float&#39;.