LayoutOverrideSource.cpp revision 249423
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" 11249423Sdim#include "clang/Basic/CharInfo.h" 12234287Sdim#include "llvm/Support/raw_ostream.h" 13234287Sdim#include <fstream> 14234287Sdim#include <string> 15234287Sdim 16234287Sdimusing namespace clang; 17234287Sdim 18234287Sdim/// \brief Parse a simple identifier. 19234287Sdimstatic std::string parseName(StringRef S) { 20249423Sdim if (S.empty() || !isIdentifierHead(S[0])) 21249423Sdim return ""; 22249423Sdim 23249423Sdim unsigned Offset = 1; 24249423Sdim while (Offset < S.size() && isIdentifierBody(S[Offset])) 25234287Sdim ++Offset; 26234287Sdim 27234287Sdim return S.substr(0, Offset).str(); 28234287Sdim} 29234287Sdim 30249423SdimLayoutOverrideSource::LayoutOverrideSource(StringRef Filename) { 31234287Sdim std::ifstream Input(Filename.str().c_str()); 32234287Sdim if (!Input.is_open()) 33234287Sdim return; 34234287Sdim 35234287Sdim // Parse the output of -fdump-record-layouts. 36234287Sdim std::string CurrentType; 37234287Sdim Layout CurrentLayout; 38234287Sdim bool ExpectingType = false; 39234287Sdim 40234287Sdim while (Input.good()) { 41234287Sdim std::string Line; 42234287Sdim getline(Input, Line); 43234287Sdim 44234287Sdim StringRef LineStr(Line); 45234287Sdim 46234287Sdim // Determine whether the following line will start a 47234287Sdim if (LineStr.find("*** Dumping AST Record Layout") != StringRef::npos) { 48234287Sdim // Flush the last type/layout, if there is one. 49234287Sdim if (!CurrentType.empty()) 50234287Sdim Layouts[CurrentType] = CurrentLayout; 51234287Sdim CurrentLayout = Layout(); 52234287Sdim 53234287Sdim ExpectingType = true; 54234287Sdim continue; 55234287Sdim } 56234287Sdim 57234287Sdim // If we're expecting a type, grab it. 58234287Sdim if (ExpectingType) { 59234287Sdim ExpectingType = false; 60234287Sdim 61234287Sdim StringRef::size_type Pos; 62234287Sdim if ((Pos = LineStr.find("struct ")) != StringRef::npos) 63234287Sdim LineStr = LineStr.substr(Pos + strlen("struct ")); 64234287Sdim else if ((Pos = LineStr.find("class ")) != StringRef::npos) 65234287Sdim LineStr = LineStr.substr(Pos + strlen("class ")); 66234287Sdim else if ((Pos = LineStr.find("union ")) != StringRef::npos) 67234287Sdim LineStr = LineStr.substr(Pos + strlen("union ")); 68234287Sdim else 69234287Sdim continue; 70234287Sdim 71234287Sdim // Find the name of the type. 72234287Sdim CurrentType = parseName(LineStr); 73234287Sdim CurrentLayout = Layout(); 74234287Sdim continue; 75234287Sdim } 76234287Sdim 77234287Sdim // Check for the size of the type. 78234287Sdim StringRef::size_type Pos = LineStr.find(" Size:"); 79234287Sdim if (Pos != StringRef::npos) { 80234287Sdim // Skip past the " Size:" prefix. 81234287Sdim LineStr = LineStr.substr(Pos + strlen(" Size:")); 82234287Sdim 83234287Sdim unsigned long long Size = 0; 84234287Sdim (void)LineStr.getAsInteger(10, Size); 85234287Sdim CurrentLayout.Size = Size; 86234287Sdim continue; 87234287Sdim } 88234287Sdim 89234287Sdim // Check for the alignment of the type. 90234287Sdim Pos = LineStr.find("Alignment:"); 91234287Sdim if (Pos != StringRef::npos) { 92234287Sdim // Skip past the "Alignment:" prefix. 93234287Sdim LineStr = LineStr.substr(Pos + strlen("Alignment:")); 94234287Sdim 95234287Sdim unsigned long long Alignment = 0; 96234287Sdim (void)LineStr.getAsInteger(10, Alignment); 97234287Sdim CurrentLayout.Align = Alignment; 98234287Sdim continue; 99234287Sdim } 100234287Sdim 101234287Sdim // Check for the size/alignment of the type. 102234287Sdim Pos = LineStr.find("sizeof="); 103234287Sdim if (Pos != StringRef::npos) { 104234287Sdim /* Skip past the sizeof= prefix. */ 105234287Sdim LineStr = LineStr.substr(Pos + strlen("sizeof=")); 106234287Sdim 107234287Sdim // Parse size. 108234287Sdim unsigned long long Size = 0; 109234287Sdim (void)LineStr.getAsInteger(10, Size); 110234287Sdim CurrentLayout.Size = Size; 111234287Sdim 112234287Sdim Pos = LineStr.find("align="); 113234287Sdim if (Pos != StringRef::npos) { 114234287Sdim /* Skip past the align= prefix. */ 115234287Sdim LineStr = LineStr.substr(Pos + strlen("align=")); 116234287Sdim 117234287Sdim // Parse alignment. 118234287Sdim unsigned long long Alignment = 0; 119234287Sdim (void)LineStr.getAsInteger(10, Alignment); 120234287Sdim CurrentLayout.Align = Alignment; 121234287Sdim } 122234287Sdim 123234287Sdim continue; 124234287Sdim } 125234287Sdim 126234287Sdim // Check for the field offsets of the type. 127234287Sdim Pos = LineStr.find("FieldOffsets: ["); 128234287Sdim if (Pos == StringRef::npos) 129234287Sdim continue; 130234287Sdim 131234287Sdim LineStr = LineStr.substr(Pos + strlen("FieldOffsets: [")); 132249423Sdim while (!LineStr.empty() && isDigit(LineStr[0])) { 133234287Sdim // Parse this offset. 134234287Sdim unsigned Idx = 1; 135249423Sdim while (Idx < LineStr.size() && isDigit(LineStr[Idx])) 136234287Sdim ++Idx; 137234287Sdim 138234287Sdim unsigned long long Offset = 0; 139234287Sdim (void)LineStr.substr(0, Idx).getAsInteger(10, Offset); 140234287Sdim 141234287Sdim CurrentLayout.FieldOffsets.push_back(Offset); 142234287Sdim 143234287Sdim // Skip over this offset, the following comma, and any spaces. 144234287Sdim LineStr = LineStr.substr(Idx + 1); 145249423Sdim while (!LineStr.empty() && isWhitespace(LineStr[0])) 146234287Sdim LineStr = LineStr.substr(1); 147234287Sdim } 148234287Sdim } 149234287Sdim 150234287Sdim // Flush the last type/layout, if there is one. 151234287Sdim if (!CurrentType.empty()) 152234287Sdim Layouts[CurrentType] = CurrentLayout; 153234287Sdim} 154234287Sdim 155234287Sdimbool 156234287SdimLayoutOverrideSource::layoutRecordType(const RecordDecl *Record, 157234287Sdim uint64_t &Size, uint64_t &Alignment, 158234287Sdim llvm::DenseMap<const FieldDecl *, uint64_t> &FieldOffsets, 159234287Sdim llvm::DenseMap<const CXXRecordDecl *, CharUnits> &BaseOffsets, 160234287Sdim llvm::DenseMap<const CXXRecordDecl *, CharUnits> &VirtualBaseOffsets) 161234287Sdim{ 162234287Sdim // We can't override unnamed declarations. 163234287Sdim if (!Record->getIdentifier()) 164234287Sdim return false; 165234287Sdim 166234287Sdim // Check whether we have a layout for this record. 167234287Sdim llvm::StringMap<Layout>::iterator Known = Layouts.find(Record->getName()); 168234287Sdim if (Known == Layouts.end()) 169234287Sdim return false; 170234287Sdim 171234287Sdim // Provide field layouts. 172234287Sdim unsigned NumFields = 0; 173234287Sdim for (RecordDecl::field_iterator F = Record->field_begin(), 174234287Sdim FEnd = Record->field_end(); 175234287Sdim F != FEnd; ++F, ++NumFields) { 176234287Sdim if (NumFields >= Known->second.FieldOffsets.size()) 177234287Sdim continue; 178234287Sdim 179234287Sdim FieldOffsets[*F] = Known->second.FieldOffsets[NumFields]; 180234287Sdim } 181234287Sdim 182234287Sdim // Wrong number of fields. 183234287Sdim if (NumFields != Known->second.FieldOffsets.size()) 184234287Sdim return false; 185234287Sdim 186234287Sdim Size = Known->second.Size; 187234287Sdim Alignment = Known->second.Align; 188234287Sdim return true; 189234287Sdim} 190234287Sdim 191234287Sdimvoid LayoutOverrideSource::dump() { 192249423Sdim raw_ostream &OS = llvm::errs(); 193234287Sdim for (llvm::StringMap<Layout>::iterator L = Layouts.begin(), 194234287Sdim LEnd = Layouts.end(); 195234287Sdim L != LEnd; ++L) { 196234287Sdim OS << "Type: blah " << L->first() << '\n'; 197234287Sdim OS << " Size:" << L->second.Size << '\n'; 198234287Sdim OS << " Alignment:" << L->second.Align << '\n'; 199234287Sdim OS << " FieldOffsets: ["; 200234287Sdim for (unsigned I = 0, N = L->second.FieldOffsets.size(); I != N; ++I) { 201234287Sdim if (I) 202234287Sdim OS << ", "; 203234287Sdim OS << L->second.FieldOffsets[I]; 204234287Sdim } 205234287Sdim OS << "]\n"; 206234287Sdim } 207234287Sdim} 208234287Sdim 209