LLVM  10.0.0svn
DebugHandlerBase.h
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1 //===-- llvm/CodeGen/DebugHandlerBase.h -----------------------*- 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 // Common functionality for different debug information format backends.
10 // LLVM currently supports DWARF and CodeView.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_CODEGEN_DEBUGHANDLERBASE_H
15 #define LLVM_CODEGEN_DEBUGHANDLERBASE_H
16 
17 #include "llvm/ADT/Optional.h"
23 
24 namespace llvm {
25 
26 class AsmPrinter;
27 class MachineInstr;
28 class MachineModuleInfo;
29 
30 /// Represents the location at which a variable is stored.
32  /// Base register.
33  unsigned Register;
34 
35  /// Chain of offsetted loads necessary to load the value if it lives in
36  /// memory. Every load except for the last is pointer-sized.
38 
39  /// Present if the location is part of a larger variable.
41 
42  /// Extract a VariableLocation from a MachineInstr.
43  /// This will only work if Instruction is a debug value instruction
44  /// and the associated DIExpression is in one of the supported forms.
45  /// If these requirements are not met, the returned Optional will not
46  /// have a value.
49 };
50 
51 /// Base class for debug information backends. Common functionality related to
52 /// tracking which variables and scopes are alive at a given PC live here.
54 protected:
56 
57  /// Target of debug info emission.
59 
60  /// Collected machine module information.
62 
63  /// Previous instruction's location information. This is used to
64  /// determine label location to indicate scope boundaries in debug info.
65  /// We track the previous instruction's source location (if not line 0),
66  /// whether it was a label, and its parent BB.
68  MCSymbol *PrevLabel = nullptr;
69  const MachineBasicBlock *PrevInstBB = nullptr;
70 
71  /// This location indicates end of function prologue and beginning of
72  /// function body.
74 
75  /// If nonnull, stores the current machine instruction we're processing.
76  const MachineInstr *CurMI = nullptr;
77 
79 
80  /// History of DBG_VALUE and clobber instructions for each user
81  /// variable. Variables are listed in order of appearance.
83 
84  /// Mapping of inlined labels and DBG_LABEL machine instruction.
86 
87  /// Maps instruction with label emitted before instruction.
88  /// FIXME: Make this private from DwarfDebug, we have the necessary accessors
89  /// for it.
91 
92  /// Maps instruction with label emitted after instruction.
94 
95  /// Indentify instructions that are marking the beginning of or
96  /// ending of a scope.
97  void identifyScopeMarkers();
98 
99  /// Ensure that a label will be emitted before MI.
101  LabelsBeforeInsn.insert(std::make_pair(MI, nullptr));
102  }
103 
104  /// Ensure that a label will be emitted after MI.
106  LabelsAfterInsn.insert(std::make_pair(MI, nullptr));
107  }
108 
109  virtual void beginFunctionImpl(const MachineFunction *MF) = 0;
110  virtual void endFunctionImpl(const MachineFunction *MF) = 0;
111  virtual void skippedNonDebugFunction() {}
112 
113  // AsmPrinterHandler overrides.
114 public:
115  void beginInstruction(const MachineInstr *MI) override;
116  void endInstruction() override;
117 
118  void beginFunction(const MachineFunction *MF) override;
119  void endFunction(const MachineFunction *MF) override;
120 
121  /// Return Label preceding the instruction.
122  MCSymbol *getLabelBeforeInsn(const MachineInstr *MI);
123 
124  /// Return Label immediately following the instruction.
125  MCSymbol *getLabelAfterInsn(const MachineInstr *MI);
126 
127  /// Return the function-local offset of an instruction. A label for the
128  /// instruction \p MI should exist (\ref getLabelAfterInsn).
129  const MCExpr *getFunctionLocalOffsetAfterInsn(const MachineInstr *MI);
130 
131  /// If this type is derived from a base type then return base type size.
132  static uint64_t getBaseTypeSize(const DIType *Ty);
133 };
134 
135 }
136 
137 #endif
For each inlined instance of a source-level label, keep the corresponding DBG_LABEL instruction...
This class represents lattice values for constants.
Definition: AllocatorList.h:23
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:41
Collects and handles AsmPrinter objects required to build debug or EH information.
A debug info location.
Definition: DebugLoc.h:33
For each user variable, keep a list of instruction ranges where this variable is accessible.
std::pair< iterator, bool > insert(const std::pair< KeyT, ValueT > &KV)
Definition: DenseMap.h:195
DebugLoc PrevInstLoc
Previous instruction&#39;s location information.
DbgLabelInstrMap DbgLabels
Mapping of inlined labels and DBG_LABEL machine instruction.
DbgValueHistoryMap DbgValues
History of DBG_VALUE and clobber instructions for each user variable.
Base class for the full range of assembler expressions which are needed for parsing.
Definition: MCExpr.h:35
DenseMap< const MachineInstr *, MCSymbol * > LabelsAfterInsn
Maps instruction with label emitted after instruction.
void requestLabelBeforeInsn(const MachineInstr *MI)
Ensure that a label will be emitted before MI.
AsmPrinter * Asm
Target of debug info emission.
llvm::Optional< llvm::DIExpression::FragmentInfo > FragmentInfo
Present if the location is part of a larger variable.
This class is intended to be used as a driving class for all asm writers.
Definition: AsmPrinter.h:78
DenseMap< const MachineInstr *, MCSymbol * > LabelsBeforeInsn
Maps instruction with label emitted before instruction.
virtual void skippedNonDebugFunction()
Represents the location at which a variable is stored.
static Optional< DbgVariableLocation > extractFromMachineInstruction(const MachineInstr &Instruction)
Extract a VariableLocation from a MachineInstr.
Base class for types.
DebugLoc PrologEndLoc
This location indicates end of function prologue and beginning of function body.
void requestLabelAfterInsn(const MachineInstr *MI)
Ensure that a label will be emitted after MI.
Representation of each machine instruction.
Definition: MachineInstr.h:63
LexicalScopes - This class provides interface to collect and use lexical scoping information from mac...
Base class for debug information backends.
SmallVector< int64_t, 1 > LoadChain
Chain of offsetted loads necessary to load the value if it lives in memory.
MachineModuleInfo * MMI
Collected machine module information.
IRTranslator LLVM IR MI
unsigned Register
Base register.
This class contains meta information specific to a module.