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