1 //===-- DwarfException.h - Dwarf Exception Framework -----------*- 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 // This file contains support for writing dwarf exception info into asm files. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_CODEGEN_ASMPRINTER_DWARFEXCEPTION_H 15 #define LLVM_CODEGEN_ASMPRINTER_DWARFEXCEPTION_H 16 17 #include "llvm/ADT/DenseMap.h" 18 #include "llvm/CodeGen/AsmPrinter.h" 19 #include <vector> 20 21 namespace llvm { 22 23 template <typename T> class SmallVectorImpl; 24 struct LandingPadInfo; 25 class MachineModuleInfo; 26 class MachineMove; 27 class MachineInstr; 28 class MachineFunction; 29 class MCAsmInfo; 30 class MCExpr; 31 class MCSymbol; 32 class Function; 33 class AsmPrinter; 34 35 //===----------------------------------------------------------------------===// 36 /// DwarfException - Emits Dwarf exception handling directives. 37 /// 38 class DwarfException { 39 protected: 40 /// Asm - Target of Dwarf emission. 41 AsmPrinter *Asm; 42 43 /// MMI - Collected machine module information. 44 MachineModuleInfo *MMI; 45 46 /// SharedTypeIds - How many leading type ids two landing pads have in common. 47 static unsigned SharedTypeIds(const LandingPadInfo *L, 48 const LandingPadInfo *R); 49 50 /// PadLT - Order landing pads lexicographically by type id. 51 static bool PadLT(const LandingPadInfo *L, const LandingPadInfo *R); 52 53 /// PadRange - Structure holding a try-range and the associated landing pad. 54 struct PadRange { 55 // The index of the landing pad. 56 unsigned PadIndex; 57 // The index of the begin and end labels in the landing pad's label lists. 58 unsigned RangeIndex; 59 }; 60 61 typedef DenseMap<MCSymbol *, PadRange> RangeMapType; 62 63 /// ActionEntry - Structure describing an entry in the actions table. 64 struct ActionEntry { 65 int ValueForTypeID; // The value to write - may not be equal to the type id. 66 int NextAction; 67 unsigned Previous; 68 }; 69 70 /// CallSiteEntry - Structure describing an entry in the call-site table. 71 struct CallSiteEntry { 72 // The 'try-range' is BeginLabel .. EndLabel. 73 MCSymbol *BeginLabel; // zero indicates the start of the function. 74 MCSymbol *EndLabel; // zero indicates the end of the function. 75 76 // The landing pad starts at PadLabel. 77 MCSymbol *PadLabel; // zero indicates that there is no landing pad. 78 unsigned Action; 79 }; 80 81 /// ComputeActionsTable - Compute the actions table and gather the first 82 /// action index for each landing pad site. 83 unsigned ComputeActionsTable(const SmallVectorImpl<const LandingPadInfo*>&LPs, 84 SmallVectorImpl<ActionEntry> &Actions, 85 SmallVectorImpl<unsigned> &FirstActions); 86 87 /// CallToNoUnwindFunction - Return `true' if this is a call to a function 88 /// marked `nounwind'. Return `false' otherwise. 89 bool CallToNoUnwindFunction(const MachineInstr *MI); 90 91 /// ComputeCallSiteTable - Compute the call-site table. The entry for an 92 /// invoke has a try-range containing the call, a non-zero landing pad and an 93 /// appropriate action. The entry for an ordinary call has a try-range 94 /// containing the call and zero for the landing pad and the action. Calls 95 /// marked 'nounwind' have no entry and must not be contained in the try-range 96 /// of any entry - they form gaps in the table. Entries must be ordered by 97 /// try-range address. 98 void ComputeCallSiteTable(SmallVectorImpl<CallSiteEntry> &CallSites, 99 const RangeMapType &PadMap, 100 const SmallVectorImpl<const LandingPadInfo *> &LPs, 101 const SmallVectorImpl<unsigned> &FirstActions); 102 103 /// EmitExceptionTable - Emit landing pads and actions. 104 /// 105 /// The general organization of the table is complex, but the basic concepts 106 /// are easy. First there is a header which describes the location and 107 /// organization of the three components that follow. 108 /// 1. The landing pad site information describes the range of code covered 109 /// by the try. In our case it's an accumulation of the ranges covered 110 /// by the invokes in the try. There is also a reference to the landing 111 /// pad that handles the exception once processed. Finally an index into 112 /// the actions table. 113 /// 2. The action table, in our case, is composed of pairs of type ids 114 /// and next action offset. Starting with the action index from the 115 /// landing pad site, each type Id is checked for a match to the current 116 /// exception. If it matches then the exception and type id are passed 117 /// on to the landing pad. Otherwise the next action is looked up. This 118 /// chain is terminated with a next action of zero. If no type id is 119 /// found the frame is unwound and handling continues. 120 /// 3. Type id table contains references to all the C++ typeinfo for all 121 /// catches in the function. This tables is reversed indexed base 1. 122 void EmitExceptionTable(); 123 124 virtual void EmitTypeInfos(unsigned TTypeEncoding); 125 126 public: 127 //===--------------------------------------------------------------------===// 128 // Main entry points. 129 // 130 DwarfException(AsmPrinter *A); 131 virtual ~DwarfException(); 132 133 /// EndModule - Emit all exception information that should come after the 134 /// content. 135 virtual void EndModule(); 136 137 /// BeginFunction - Gather pre-function exception information. Assumes being 138 /// emitted immediately after the function entry point. 139 virtual void BeginFunction(const MachineFunction *MF); 140 141 /// EndFunction - Gather and emit post-function exception information. 142 virtual void EndFunction(); 143 }; 144 145 class DwarfCFIException : public DwarfException { 146 /// shouldEmitPersonality - Per-function flag to indicate if .cfi_personality 147 /// should be emitted. 148 bool shouldEmitPersonality; 149 150 /// shouldEmitLSDA - Per-function flag to indicate if .cfi_lsda 151 /// should be emitted. 152 bool shouldEmitLSDA; 153 154 /// shouldEmitMoves - Per-function flag to indicate if frame moves info 155 /// should be emitted. 156 bool shouldEmitMoves; 157 158 AsmPrinter::CFIMoveType moveTypeModule; 159 160 public: 161 //===--------------------------------------------------------------------===// 162 // Main entry points. 163 // 164 DwarfCFIException(AsmPrinter *A); 165 virtual ~DwarfCFIException(); 166 167 /// EndModule - Emit all exception information that should come after the 168 /// content. 169 virtual void EndModule(); 170 171 /// BeginFunction - Gather pre-function exception information. Assumes being 172 /// emitted immediately after the function entry point. 173 virtual void BeginFunction(const MachineFunction *MF); 174 175 /// EndFunction - Gather and emit post-function exception information. 176 virtual void EndFunction(); 177 }; 178 179 class ARMException : public DwarfException { 180 void EmitTypeInfos(unsigned TTypeEncoding); 181 public: 182 //===--------------------------------------------------------------------===// 183 // Main entry points. 184 // 185 ARMException(AsmPrinter *A); 186 virtual ~ARMException(); 187 188 /// EndModule - Emit all exception information that should come after the 189 /// content. 190 virtual void EndModule(); 191 192 /// BeginFunction - Gather pre-function exception information. Assumes being 193 /// emitted immediately after the function entry point. 194 virtual void BeginFunction(const MachineFunction *MF); 195 196 /// EndFunction - Gather and emit post-function exception information. 197 virtual void EndFunction(); 198 }; 199 200 class Win64Exception : public DwarfException { 201 /// shouldEmitPersonality - Per-function flag to indicate if personality 202 /// info should be emitted. 203 bool shouldEmitPersonality; 204 205 /// shouldEmitLSDA - Per-function flag to indicate if the LSDA 206 /// should be emitted. 207 bool shouldEmitLSDA; 208 209 /// shouldEmitMoves - Per-function flag to indicate if frame moves info 210 /// should be emitted. 211 bool shouldEmitMoves; 212 213 public: 214 //===--------------------------------------------------------------------===// 215 // Main entry points. 216 // 217 Win64Exception(AsmPrinter *A); 218 virtual ~Win64Exception(); 219 220 /// EndModule - Emit all exception information that should come after the 221 /// content. 222 virtual void EndModule(); 223 224 /// BeginFunction - Gather pre-function exception information. Assumes being 225 /// emitted immediately after the function entry point. 226 virtual void BeginFunction(const MachineFunction *MF); 227 228 /// EndFunction - Gather and emit post-function exception information. 229 virtual void EndFunction(); 230 }; 231 232 } // End of namespace llvm 233 234 #endif 235
