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1 //===--- lib/CodeGen/DIE.h - DWARF Info Entries -----------------*- 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 //===----------------------------------------------------------------------===//
9 //
10 // Data structures for DWARF info entries.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef CODEGEN_ASMPRINTER_DIE_H__
15 #define CODEGEN_ASMPRINTER_DIE_H__
16 
17 #include "llvm/ADT/FoldingSet.h"
18 #include "llvm/ADT/SmallVector.h"
19 #include "llvm/Support/Compiler.h"
20 #include "llvm/Support/Dwarf.h"
21 #include <vector>
22 
23 namespace llvm {
24   class AsmPrinter;
25   class MCSymbol;
26   class raw_ostream;
27 
28   //===--------------------------------------------------------------------===//
29   /// DIEAbbrevData - Dwarf abbreviation data, describes the one attribute of a
30   /// Dwarf abbreviation.
31   class DIEAbbrevData {
32     /// Attribute - Dwarf attribute code.
33     ///
34     uint16_t Attribute;
35 
36     /// Form - Dwarf form code.
37     ///
38     uint16_t Form;
39   public:
DIEAbbrevData(uint16_t A,uint16_t F)40     DIEAbbrevData(uint16_t A, uint16_t F) : Attribute(A), Form(F) {}
41 
42     // Accessors.
getAttribute()43     uint16_t getAttribute() const { return Attribute; }
getForm()44     uint16_t getForm()      const { return Form; }
45 
46     /// Profile - Used to gather unique data for the abbreviation folding set.
47     ///
48     void Profile(FoldingSetNodeID &ID) const;
49   };
50 
51   //===--------------------------------------------------------------------===//
52   /// DIEAbbrev - Dwarf abbreviation, describes the organization of a debug
53   /// information object.
54   class DIEAbbrev : public FoldingSetNode {
55     /// Tag - Dwarf tag code.
56     ///
57     uint16_t Tag;
58 
59     /// ChildrenFlag - Dwarf children flag.
60     ///
61     uint16_t ChildrenFlag;
62 
63     /// Unique number for node.
64     ///
65     unsigned Number;
66 
67     /// Data - Raw data bytes for abbreviation.
68     ///
69     SmallVector<DIEAbbrevData, 8> Data;
70 
71   public:
DIEAbbrev(uint16_t T,uint16_t C)72     DIEAbbrev(uint16_t T, uint16_t C) : Tag(T), ChildrenFlag(C), Data() {}
73 
74     // Accessors.
getTag()75     uint16_t getTag() const { return Tag; }
getNumber()76     unsigned getNumber() const { return Number; }
getChildrenFlag()77     uint16_t getChildrenFlag() const { return ChildrenFlag; }
getData()78     const SmallVector<DIEAbbrevData, 8> &getData() const { return Data; }
setTag(uint16_t T)79     void setTag(uint16_t T) { Tag = T; }
setChildrenFlag(uint16_t CF)80     void setChildrenFlag(uint16_t CF) { ChildrenFlag = CF; }
setNumber(unsigned N)81     void setNumber(unsigned N) { Number = N; }
82 
83     /// AddAttribute - Adds another set of attribute information to the
84     /// abbreviation.
AddAttribute(uint16_t Attribute,uint16_t Form)85     void AddAttribute(uint16_t Attribute, uint16_t Form) {
86       Data.push_back(DIEAbbrevData(Attribute, Form));
87     }
88 
89     /// AddFirstAttribute - Adds a set of attribute information to the front
90     /// of the abbreviation.
AddFirstAttribute(uint16_t Attribute,uint16_t Form)91     void AddFirstAttribute(uint16_t Attribute, uint16_t Form) {
92       Data.insert(Data.begin(), DIEAbbrevData(Attribute, Form));
93     }
94 
95     /// Profile - Used to gather unique data for the abbreviation folding set.
96     ///
97     void Profile(FoldingSetNodeID &ID) const;
98 
99     /// Emit - Print the abbreviation using the specified asm printer.
100     ///
101     void Emit(AsmPrinter *AP) const;
102 
103 #ifndef NDEBUG
104     void print(raw_ostream &O);
105     void dump();
106 #endif
107   };
108 
109   //===--------------------------------------------------------------------===//
110   /// DIE - A structured debug information entry.  Has an abbreviation which
111   /// describes it's organization.
112   class DIEValue;
113 
114   class DIE {
115   protected:
116     /// Offset - Offset in debug info section.
117     ///
118     unsigned Offset;
119 
120     /// Size - Size of instance + children.
121     ///
122     unsigned Size;
123 
124     /// Abbrev - Buffer for constructing abbreviation.
125     ///
126     DIEAbbrev Abbrev;
127 
128     /// Children DIEs.
129     ///
130     std::vector<DIE *> Children;
131 
132     DIE *Parent;
133 
134     /// Attributes values.
135     ///
136     SmallVector<DIEValue*, 32> Values;
137 
138     // Private data for print()
139     mutable unsigned IndentCount;
140   public:
DIE(unsigned Tag)141     explicit DIE(unsigned Tag)
142       : Offset(0), Size(0), Abbrev(Tag, dwarf::DW_CHILDREN_no), Parent(0),
143         IndentCount(0) {}
144     virtual ~DIE();
145 
146     // Accessors.
getAbbrev()147     DIEAbbrev &getAbbrev() { return Abbrev; }
getAbbrevNumber()148     unsigned getAbbrevNumber() const { return Abbrev.getNumber(); }
getTag()149     unsigned getTag() const { return Abbrev.getTag(); }
getOffset()150     unsigned getOffset() const { return Offset; }
getSize()151     unsigned getSize() const { return Size; }
getChildren()152     const std::vector<DIE *> &getChildren() const { return Children; }
getValues()153     const SmallVector<DIEValue*, 32> &getValues() const { return Values; }
getParent()154     DIE *getParent() const { return Parent; }
setTag(unsigned Tag)155     void setTag(unsigned Tag) { Abbrev.setTag(Tag); }
setOffset(unsigned O)156     void setOffset(unsigned O) { Offset = O; }
setSize(unsigned S)157     void setSize(unsigned S) { Size = S; }
158 
159     /// addValue - Add a value and attributes to a DIE.
160     ///
addValue(unsigned Attribute,unsigned Form,DIEValue * Value)161     void addValue(unsigned Attribute, unsigned Form, DIEValue *Value) {
162       Abbrev.AddAttribute(Attribute, Form);
163       Values.push_back(Value);
164     }
165 
166     /// addChild - Add a child to the DIE.
167     ///
addChild(DIE * Child)168     void addChild(DIE *Child) {
169       if (Child->getParent()) {
170         assert (Child->getParent() == this && "Unexpected DIE Parent!");
171         return;
172       }
173       Abbrev.setChildrenFlag(dwarf::DW_CHILDREN_yes);
174       Children.push_back(Child);
175       Child->Parent = this;
176     }
177 
178 #ifndef NDEBUG
179     void print(raw_ostream &O, unsigned IncIndent = 0);
180     void dump();
181 #endif
182   };
183 
184   //===--------------------------------------------------------------------===//
185   /// DIEValue - A debug information entry value.
186   ///
187   class DIEValue {
188     virtual void anchor();
189   public:
190     enum {
191       isInteger,
192       isString,
193       isLabel,
194       isDelta,
195       isEntry,
196       isBlock
197     };
198   protected:
199     /// Type - Type of data stored in the value.
200     ///
201     unsigned Type;
202   public:
DIEValue(unsigned T)203     explicit DIEValue(unsigned T) : Type(T) {}
~DIEValue()204     virtual ~DIEValue() {}
205 
206     // Accessors
getType()207     unsigned getType()  const { return Type; }
208 
209     /// EmitValue - Emit value via the Dwarf writer.
210     ///
211     virtual void EmitValue(AsmPrinter *AP, unsigned Form) const = 0;
212 
213     /// SizeOf - Return the size of a value in bytes.
214     ///
215     virtual unsigned SizeOf(AsmPrinter *AP, unsigned Form) const = 0;
216 
217     // Implement isa/cast/dyncast.
classof(const DIEValue *)218     static bool classof(const DIEValue *) { return true; }
219 
220 #ifndef NDEBUG
221     virtual void print(raw_ostream &O) = 0;
222     void dump();
223 #endif
224   };
225 
226   //===--------------------------------------------------------------------===//
227   /// DIEInteger - An integer value DIE.
228   ///
229   class DIEInteger : public DIEValue {
230     uint64_t Integer;
231   public:
DIEInteger(uint64_t I)232     explicit DIEInteger(uint64_t I) : DIEValue(isInteger), Integer(I) {}
233 
234     /// BestForm - Choose the best form for integer.
235     ///
BestForm(bool IsSigned,uint64_t Int)236     static unsigned BestForm(bool IsSigned, uint64_t Int) {
237       if (IsSigned) {
238         if ((char)Int == (signed)Int)   return dwarf::DW_FORM_data1;
239         if ((short)Int == (signed)Int)  return dwarf::DW_FORM_data2;
240         if ((int)Int == (signed)Int)    return dwarf::DW_FORM_data4;
241       } else {
242         if ((unsigned char)Int == Int)  return dwarf::DW_FORM_data1;
243         if ((unsigned short)Int == Int) return dwarf::DW_FORM_data2;
244         if ((unsigned int)Int == Int)   return dwarf::DW_FORM_data4;
245       }
246       return dwarf::DW_FORM_data8;
247     }
248 
249     /// EmitValue - Emit integer of appropriate size.
250     ///
251     virtual void EmitValue(AsmPrinter *AP, unsigned Form) const;
252 
getValue()253     uint64_t getValue() const { return Integer; }
254 
255     /// SizeOf - Determine size of integer value in bytes.
256     ///
257     virtual unsigned SizeOf(AsmPrinter *AP, unsigned Form) const;
258 
259     // Implement isa/cast/dyncast.
classof(const DIEInteger *)260     static bool classof(const DIEInteger *) { return true; }
classof(const DIEValue * I)261     static bool classof(const DIEValue *I) { return I->getType() == isInteger; }
262 
263 #ifndef NDEBUG
264     virtual void print(raw_ostream &O);
265 #endif
266   };
267 
268   //===--------------------------------------------------------------------===//
269   /// DIELabel - A label expression DIE.
270   //
271   class DIELabel : public DIEValue {
272     const MCSymbol *Label;
273   public:
DIELabel(const MCSymbol * L)274     explicit DIELabel(const MCSymbol *L) : DIEValue(isLabel), Label(L) {}
275 
276     /// EmitValue - Emit label value.
277     ///
278     virtual void EmitValue(AsmPrinter *AP, unsigned Form) const;
279 
280     /// getValue - Get MCSymbol.
281     ///
getValue()282     const MCSymbol *getValue()       const { return Label; }
283 
284     /// SizeOf - Determine size of label value in bytes.
285     ///
286     virtual unsigned SizeOf(AsmPrinter *AP, unsigned Form) const;
287 
288     // Implement isa/cast/dyncast.
classof(const DIELabel *)289     static bool classof(const DIELabel *)  { return true; }
classof(const DIEValue * L)290     static bool classof(const DIEValue *L) { return L->getType() == isLabel; }
291 
292 #ifndef NDEBUG
293     virtual void print(raw_ostream &O);
294 #endif
295   };
296 
297   //===--------------------------------------------------------------------===//
298   /// DIEDelta - A simple label difference DIE.
299   ///
300   class DIEDelta : public DIEValue {
301     const MCSymbol *LabelHi;
302     const MCSymbol *LabelLo;
303   public:
DIEDelta(const MCSymbol * Hi,const MCSymbol * Lo)304     DIEDelta(const MCSymbol *Hi, const MCSymbol *Lo)
305       : DIEValue(isDelta), LabelHi(Hi), LabelLo(Lo) {}
306 
307     /// EmitValue - Emit delta value.
308     ///
309     virtual void EmitValue(AsmPrinter *AP, unsigned Form) const;
310 
311     /// SizeOf - Determine size of delta value in bytes.
312     ///
313     virtual unsigned SizeOf(AsmPrinter *AP, unsigned Form) const;
314 
315     // Implement isa/cast/dyncast.
classof(const DIEDelta *)316     static bool classof(const DIEDelta *)  { return true; }
classof(const DIEValue * D)317     static bool classof(const DIEValue *D) { return D->getType() == isDelta; }
318 
319 #ifndef NDEBUG
320     virtual void print(raw_ostream &O);
321 #endif
322   };
323 
324   //===--------------------------------------------------------------------===//
325   /// DIEEntry - A pointer to another debug information entry.  An instance of
326   /// this class can also be used as a proxy for a debug information entry not
327   /// yet defined (ie. types.)
328   class DIEEntry : public DIEValue {
329     DIE *const Entry;
330   public:
DIEEntry(DIE * E)331     explicit DIEEntry(DIE *E) : DIEValue(isEntry), Entry(E) {}
332 
getEntry()333     DIE *getEntry() const { return Entry; }
334 
335     /// EmitValue - Emit debug information entry offset.
336     ///
337     virtual void EmitValue(AsmPrinter *AP, unsigned Form) const;
338 
339     /// SizeOf - Determine size of debug information entry in bytes.
340     ///
SizeOf(AsmPrinter * AP,unsigned Form)341     virtual unsigned SizeOf(AsmPrinter *AP, unsigned Form) const {
342       return sizeof(int32_t);
343     }
344 
345     // Implement isa/cast/dyncast.
classof(const DIEEntry *)346     static bool classof(const DIEEntry *)  { return true; }
classof(const DIEValue * E)347     static bool classof(const DIEValue *E) { return E->getType() == isEntry; }
348 
349 #ifndef NDEBUG
350     virtual void print(raw_ostream &O);
351 #endif
352   };
353 
354   //===--------------------------------------------------------------------===//
355   /// DIEBlock - A block of values.  Primarily used for location expressions.
356   //
357   class DIEBlock : public DIEValue, public DIE {
358     unsigned Size;                // Size in bytes excluding size header.
359   public:
DIEBlock()360     DIEBlock()
361       : DIEValue(isBlock), DIE(0), Size(0) {}
~DIEBlock()362     virtual ~DIEBlock() {}
363 
364     /// ComputeSize - calculate the size of the block.
365     ///
366     unsigned ComputeSize(AsmPrinter *AP);
367 
368     /// BestForm - Choose the best form for data.
369     ///
BestForm()370     unsigned BestForm() const {
371       if ((unsigned char)Size == Size)  return dwarf::DW_FORM_block1;
372       if ((unsigned short)Size == Size) return dwarf::DW_FORM_block2;
373       if ((unsigned int)Size == Size)   return dwarf::DW_FORM_block4;
374       return dwarf::DW_FORM_block;
375     }
376 
377     /// EmitValue - Emit block data.
378     ///
379     virtual void EmitValue(AsmPrinter *AP, unsigned Form) const;
380 
381     /// SizeOf - Determine size of block data in bytes.
382     ///
383     virtual unsigned SizeOf(AsmPrinter *AP, unsigned Form) const;
384 
385     // Implement isa/cast/dyncast.
classof(const DIEBlock *)386     static bool classof(const DIEBlock *)  { return true; }
classof(const DIEValue * E)387     static bool classof(const DIEValue *E) { return E->getType() == isBlock; }
388 
389 #ifndef NDEBUG
390     virtual void print(raw_ostream &O);
391 #endif
392   };
393 
394 } // end llvm namespace
395 
396 #endif
397