LayoutOverrideSource.cpp revision 234287
1234287Sdim//===--- LayoutOverrideSource.cpp --Override Record Layouts ---------------===// 2234287Sdim// 3234287Sdim// The LLVM Compiler Infrastructure 4234287Sdim// 5234287Sdim// This file is distributed under the University of Illinois Open Source 6234287Sdim// License. See LICENSE.TXT for details. 7234287Sdim// 8234287Sdim//===----------------------------------------------------------------------===// 9234287Sdim#include "clang/Frontend/LayoutOverrideSource.h" 10234287Sdim#include "clang/AST/Decl.h" 11234287Sdim#include "llvm/Support/raw_ostream.h" 12234287Sdim#include <fstream> 13234287Sdim#include <string> 14234287Sdim 15234287Sdimusing namespace clang; 16234287Sdim 17234287Sdim/// \brief Parse a simple identifier. 18234287Sdimstatic std::string parseName(StringRef S) { 19234287Sdim unsigned Offset = 0; 20234287Sdim while (Offset < S.size() && 21234287Sdim (isalpha(S[Offset]) || S[Offset] == '_' || 22234287Sdim (Offset > 0 && isdigit(S[Offset])))) 23234287Sdim ++Offset; 24234287Sdim 25234287Sdim return S.substr(0, Offset).str(); 26234287Sdim} 27234287Sdim 28234287SdimLayoutOverrideSource::LayoutOverrideSource(llvm::StringRef Filename) { 29234287Sdim std::ifstream Input(Filename.str().c_str()); 30234287Sdim if (!Input.is_open()) 31234287Sdim return; 32234287Sdim 33234287Sdim // Parse the output of -fdump-record-layouts. 34234287Sdim std::string CurrentType; 35234287Sdim Layout CurrentLayout; 36234287Sdim bool ExpectingType = false; 37234287Sdim 38234287Sdim while (Input.good()) { 39234287Sdim std::string Line; 40234287Sdim getline(Input, Line); 41234287Sdim 42234287Sdim StringRef LineStr(Line); 43234287Sdim 44234287Sdim // Determine whether the following line will start a 45234287Sdim if (LineStr.find("*** Dumping AST Record Layout") != StringRef::npos) { 46234287Sdim // Flush the last type/layout, if there is one. 47234287Sdim if (!CurrentType.empty()) 48234287Sdim Layouts[CurrentType] = CurrentLayout; 49234287Sdim CurrentLayout = Layout(); 50234287Sdim 51234287Sdim ExpectingType = true; 52234287Sdim continue; 53234287Sdim } 54234287Sdim 55234287Sdim // If we're expecting a type, grab it. 56234287Sdim if (ExpectingType) { 57234287Sdim ExpectingType = false; 58234287Sdim 59234287Sdim StringRef::size_type Pos; 60234287Sdim if ((Pos = LineStr.find("struct ")) != StringRef::npos) 61234287Sdim LineStr = LineStr.substr(Pos + strlen("struct ")); 62234287Sdim else if ((Pos = LineStr.find("class ")) != StringRef::npos) 63234287Sdim LineStr = LineStr.substr(Pos + strlen("class ")); 64234287Sdim else if ((Pos = LineStr.find("union ")) != StringRef::npos) 65234287Sdim LineStr = LineStr.substr(Pos + strlen("union ")); 66234287Sdim else 67234287Sdim continue; 68234287Sdim 69234287Sdim // Find the name of the type. 70234287Sdim CurrentType = parseName(LineStr); 71234287Sdim CurrentLayout = Layout(); 72234287Sdim continue; 73234287Sdim } 74234287Sdim 75234287Sdim // Check for the size of the type. 76234287Sdim StringRef::size_type Pos = LineStr.find(" Size:"); 77234287Sdim if (Pos != StringRef::npos) { 78234287Sdim // Skip past the " Size:" prefix. 79234287Sdim LineStr = LineStr.substr(Pos + strlen(" Size:")); 80234287Sdim 81234287Sdim unsigned long long Size = 0; 82234287Sdim (void)LineStr.getAsInteger(10, Size); 83234287Sdim CurrentLayout.Size = Size; 84234287Sdim continue; 85234287Sdim } 86234287Sdim 87234287Sdim // Check for the alignment of the type. 88234287Sdim Pos = LineStr.find("Alignment:"); 89234287Sdim if (Pos != StringRef::npos) { 90234287Sdim // Skip past the "Alignment:" prefix. 91234287Sdim LineStr = LineStr.substr(Pos + strlen("Alignment:")); 92234287Sdim 93234287Sdim unsigned long long Alignment = 0; 94234287Sdim (void)LineStr.getAsInteger(10, Alignment); 95234287Sdim CurrentLayout.Align = Alignment; 96234287Sdim continue; 97234287Sdim } 98234287Sdim 99234287Sdim // Check for the size/alignment of the type. 100234287Sdim Pos = LineStr.find("sizeof="); 101234287Sdim if (Pos != StringRef::npos) { 102234287Sdim /* Skip past the sizeof= prefix. */ 103234287Sdim LineStr = LineStr.substr(Pos + strlen("sizeof=")); 104234287Sdim 105234287Sdim // Parse size. 106234287Sdim unsigned long long Size = 0; 107234287Sdim (void)LineStr.getAsInteger(10, Size); 108234287Sdim CurrentLayout.Size = Size; 109234287Sdim 110234287Sdim Pos = LineStr.find("align="); 111234287Sdim if (Pos != StringRef::npos) { 112234287Sdim /* Skip past the align= prefix. */ 113234287Sdim LineStr = LineStr.substr(Pos + strlen("align=")); 114234287Sdim 115234287Sdim // Parse alignment. 116234287Sdim unsigned long long Alignment = 0; 117234287Sdim (void)LineStr.getAsInteger(10, Alignment); 118234287Sdim CurrentLayout.Align = Alignment; 119234287Sdim } 120234287Sdim 121234287Sdim continue; 122234287Sdim } 123234287Sdim 124234287Sdim // Check for the field offsets of the type. 125234287Sdim Pos = LineStr.find("FieldOffsets: ["); 126234287Sdim if (Pos == StringRef::npos) 127234287Sdim continue; 128234287Sdim 129234287Sdim LineStr = LineStr.substr(Pos + strlen("FieldOffsets: [")); 130234287Sdim while (!LineStr.empty() && isdigit(LineStr[0])) { 131234287Sdim // Parse this offset. 132234287Sdim unsigned Idx = 1; 133234287Sdim while (Idx < LineStr.size() && isdigit(LineStr[Idx])) 134234287Sdim ++Idx; 135234287Sdim 136234287Sdim unsigned long long Offset = 0; 137234287Sdim (void)LineStr.substr(0, Idx).getAsInteger(10, Offset); 138234287Sdim 139234287Sdim CurrentLayout.FieldOffsets.push_back(Offset); 140234287Sdim 141234287Sdim // Skip over this offset, the following comma, and any spaces. 142234287Sdim LineStr = LineStr.substr(Idx + 1); 143234287Sdim while (!LineStr.empty() && isspace(LineStr[0])) 144234287Sdim LineStr = LineStr.substr(1); 145234287Sdim } 146234287Sdim } 147234287Sdim 148234287Sdim // Flush the last type/layout, if there is one. 149234287Sdim if (!CurrentType.empty()) 150234287Sdim Layouts[CurrentType] = CurrentLayout; 151234287Sdim} 152234287Sdim 153234287Sdimbool 154234287SdimLayoutOverrideSource::layoutRecordType(const RecordDecl *Record, 155234287Sdim uint64_t &Size, uint64_t &Alignment, 156234287Sdim llvm::DenseMap<const FieldDecl *, uint64_t> &FieldOffsets, 157234287Sdim llvm::DenseMap<const CXXRecordDecl *, CharUnits> &BaseOffsets, 158234287Sdim llvm::DenseMap<const CXXRecordDecl *, CharUnits> &VirtualBaseOffsets) 159234287Sdim{ 160234287Sdim // We can't override unnamed declarations. 161234287Sdim if (!Record->getIdentifier()) 162234287Sdim return false; 163234287Sdim 164234287Sdim // Check whether we have a layout for this record. 165234287Sdim llvm::StringMap<Layout>::iterator Known = Layouts.find(Record->getName()); 166234287Sdim if (Known == Layouts.end()) 167234287Sdim return false; 168234287Sdim 169234287Sdim // Provide field layouts. 170234287Sdim unsigned NumFields = 0; 171234287Sdim for (RecordDecl::field_iterator F = Record->field_begin(), 172234287Sdim FEnd = Record->field_end(); 173234287Sdim F != FEnd; ++F, ++NumFields) { 174234287Sdim if (NumFields >= Known->second.FieldOffsets.size()) 175234287Sdim continue; 176234287Sdim 177234287Sdim FieldOffsets[*F] = Known->second.FieldOffsets[NumFields]; 178234287Sdim } 179234287Sdim 180234287Sdim // Wrong number of fields. 181234287Sdim if (NumFields != Known->second.FieldOffsets.size()) 182234287Sdim return false; 183234287Sdim 184234287Sdim Size = Known->second.Size; 185234287Sdim Alignment = Known->second.Align; 186234287Sdim return true; 187234287Sdim} 188234287Sdim 189234287Sdimvoid LayoutOverrideSource::dump() { 190234287Sdim llvm::raw_ostream &OS = llvm::errs(); 191234287Sdim for (llvm::StringMap<Layout>::iterator L = Layouts.begin(), 192234287Sdim LEnd = Layouts.end(); 193234287Sdim L != LEnd; ++L) { 194234287Sdim OS << "Type: blah " << L->first() << '\n'; 195234287Sdim OS << " Size:" << L->second.Size << '\n'; 196234287Sdim OS << " Alignment:" << L->second.Align << '\n'; 197234287Sdim OS << " FieldOffsets: ["; 198234287Sdim for (unsigned I = 0, N = L->second.FieldOffsets.size(); I != N; ++I) { 199234287Sdim if (I) 200234287Sdim OS << ", "; 201234287Sdim OS << L->second.FieldOffsets[I]; 202234287Sdim } 203234287Sdim OS << "]\n"; 204234287Sdim } 205234287Sdim} 206234287Sdim 207