lib/Support/SourceMgr.cpp

   1 //===- SourceMgr.cpp - Manager for Simple Source Buffers & Diagnostics ----===//
   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 implements the SourceMgr class.  This class is used as a simple
  11 // substrate for diagnostics, #include handling, and other low level things for
  12 // simple parsers.
  13 //
  14 //===----------------------------------------------------------------------===//
  15
  16 #include "llvm/ADT/Twine.h"
  17 #include "llvm/Support/SourceMgr.h"
  18 #include "llvm/Support/MemoryBuffer.h"
  19 #include "llvm/ADT/OwningPtr.h"
  20 #include "llvm/Support/raw_ostream.h"
  21 #include "llvm/Support/system_error.h"
  22 using namespace llvm;
  23
  24 namespace {
  25   struct LineNoCacheTy {
  26     int LastQueryBufferID;
  27     const char *LastQuery;
  28     unsigned LineNoOfQuery;
  29   };
  30 }
  31
  32 static LineNoCacheTy *getCache(void *Ptr) {
  33   return (LineNoCacheTy*)Ptr;
  34 }
  35
  36
  37 SourceMgr::~SourceMgr() {
  38   // Delete the line # cache if allocated.
  39   if (LineNoCacheTy *Cache = getCache(LineNoCache))
  40     delete Cache;
  41
  42   while (!Buffers.empty()) {
  43     delete Buffers.back().Buffer;
  44     Buffers.pop_back();
  45   }
  46 }
  47
  48 /// AddIncludeFile - Search for a file with the specified name in the current
  49 /// directory or in one of the IncludeDirs.  If no file is found, this returns
  50 /// ~0, otherwise it returns the buffer ID of the stacked file.
  51 unsigned SourceMgr::AddIncludeFile(const std::string &Filename,
  52                                    SMLoc IncludeLoc) {
  53   OwningPtr<MemoryBuffer> NewBuf;
  54   MemoryBuffer::getFile(Filename.c_str(), NewBuf);
  55
  56   // If the file didn't exist directly, see if it's in an include path.
  57   for (unsigned i = 0, e = IncludeDirectories.size(); i != e && !NewBuf; ++i) {
  58     std::string IncFile = IncludeDirectories[i] + "/" + Filename;
  59     MemoryBuffer::getFile(IncFile.c_str(), NewBuf);
  60   }
  61
  62   if (NewBuf == 0) return ~0U;
  63
  64   return AddNewSourceBuffer(NewBuf.take(), IncludeLoc);
  65 }
  66
  67
  68 /// FindBufferContainingLoc - Return the ID of the buffer containing the
  69 /// specified location, returning -1 if not found.
  70 int SourceMgr::FindBufferContainingLoc(SMLoc Loc) const {
  71   for (unsigned i = 0, e = Buffers.size(); i != e; ++i)
  72     if (Loc.getPointer() >= Buffers[i].Buffer->getBufferStart() &&
  73         // Use <= here so that a pointer to the null at the end of the buffer
  74         // is included as part of the buffer.
  75         Loc.getPointer() <= Buffers[i].Buffer->getBufferEnd())
  76       return i;
  77   return -1;
  78 }
  79
  80 /// FindLineNumber - Find the line number for the specified location in the
  81 /// specified file.  This is not a fast method.
  82 unsigned SourceMgr::FindLineNumber(SMLoc Loc, int BufferID) const {
  83   if (BufferID == -1) BufferID = FindBufferContainingLoc(Loc);
  84   assert(BufferID != -1 && "Invalid Location!");
  85
  86   MemoryBuffer *Buff = getBufferInfo(BufferID).Buffer;
  87
  88   // Count the number of \n's between the start of the file and the specified
  89   // location.
  90   unsigned LineNo = 1;
  91
  92   const char *Ptr = Buff->getBufferStart();
  93
  94   // If we have a line number cache, and if the query is to a later point in the
  95   // same file, start searching from the last query location.  This optimizes
  96   // for the case when multiple diagnostics come out of one file in order.
  97   if (LineNoCacheTy *Cache = getCache(LineNoCache))
  98     if (Cache->LastQueryBufferID == BufferID &&
  99         Cache->LastQuery <= Loc.getPointer()) {
 100       Ptr = Cache->LastQuery;
 101       LineNo = Cache->LineNoOfQuery;
 102     }
 103
 104   // Scan for the location being queried, keeping track of the number of lines
 105   // we see.
 106   for (; SMLoc::getFromPointer(Ptr) != Loc; ++Ptr)
 107     if (*Ptr == '\n') ++LineNo;
 108
 109
 110   // Allocate the line number cache if it doesn't exist.
 111   if (LineNoCache == 0)
 112     LineNoCache = new LineNoCacheTy();
 113
 114   // Update the line # cache.
 115   LineNoCacheTy &Cache = *getCache(LineNoCache);
 116   Cache.LastQueryBufferID = BufferID;
 117   Cache.LastQuery = Ptr;
 118   Cache.LineNoOfQuery = LineNo;
 119   return LineNo;
 120 }
 121
 122 void SourceMgr::PrintIncludeStack(SMLoc IncludeLoc, raw_ostream &OS) const {
 123   if (IncludeLoc == SMLoc()) return;  // Top of stack.
 124
 125   int CurBuf = FindBufferContainingLoc(IncludeLoc);
 126   assert(CurBuf != -1 && "Invalid or unspecified location!");
 127
 128   PrintIncludeStack(getBufferInfo(CurBuf).IncludeLoc, OS);
 129
 130   OS << "Included from "
 131      << getBufferInfo(CurBuf).Buffer->getBufferIdentifier()
 132      << ":" << FindLineNumber(IncludeLoc, CurBuf) << ":\n";
 133 }
 134
 135
 136 /// GetMessage - Return an SMDiagnostic at the specified location with the
 137 /// specified string.
 138 ///
 139 /// @param Type - If non-null, the kind of message (e.g., "error") which is
 140 /// prefixed to the message.
 141 SMDiagnostic SourceMgr::GetMessage(SMLoc Loc, const Twine &Msg,
 142                                    const char *Type, bool ShowLine) const {
 143
 144   // First thing to do: find the current buffer containing the specified
 145   // location.
 146   int CurBuf = FindBufferContainingLoc(Loc);
 147   assert(CurBuf != -1 && "Invalid or unspecified location!");
 148
 149   MemoryBuffer *CurMB = getBufferInfo(CurBuf).Buffer;
 150
 151   // Scan backward to find the start of the line.
 152   const char *LineStart = Loc.getPointer();
 153   while (LineStart != CurMB->getBufferStart() &&
 154          LineStart[-1] != '\n' && LineStart[-1] != '\r')
 155     --LineStart;
 156
 157   std::string LineStr;
 158   if (ShowLine) {
 159     // Get the end of the line.
 160     const char *LineEnd = Loc.getPointer();
 161     while (LineEnd != CurMB->getBufferEnd() &&
 162            LineEnd[0] != '\n' && LineEnd[0] != '\r')
 163       ++LineEnd;
 164     LineStr = std::string(LineStart, LineEnd);
 165   }
 166
 167   std::string PrintedMsg;
 168   raw_string_ostream OS(PrintedMsg);
 169   if (Type)
 170     OS << Type << ": ";
 171   OS << Msg;
 172
 173   return SMDiagnostic(*this, Loc,
 174                       CurMB->getBufferIdentifier(), FindLineNumber(Loc, CurBuf),
 175                       Loc.getPointer()-LineStart, OS.str(),
 176                       LineStr, ShowLine);
 177 }
 178
 179 void SourceMgr::PrintMessage(SMLoc Loc, const Twine &Msg,
 180                              const char *Type, bool ShowLine) const {
 181   // Report the message with the diagnostic handler if present.
 182   if (DiagHandler) {
 183     DiagHandler(GetMessage(Loc, Msg, Type, ShowLine), DiagContext);
 184     return;
 185   }
 186
 187   raw_ostream &OS = errs();
 188
 189   int CurBuf = FindBufferContainingLoc(Loc);
 190   assert(CurBuf != -1 && "Invalid or unspecified location!");
 191   PrintIncludeStack(getBufferInfo(CurBuf).IncludeLoc, OS);
 192
 193   GetMessage(Loc, Msg, Type, ShowLine).Print(0, OS);
 194 }
 195
 196 //===----------------------------------------------------------------------===//
 197 // SMDiagnostic Implementation
 198 //===----------------------------------------------------------------------===//
 199
 200 void SMDiagnostic::Print(const char *ProgName, raw_ostream &S) const {
 201   if (ProgName && ProgName[0])
 202     S << ProgName << ": ";
 203
 204   if (!Filename.empty()) {
 205     if (Filename == "-")
 206       S << "<stdin>";
 207     else
 208       S << Filename;
 209
 210     if (LineNo != -1) {
 211       S << ':' << LineNo;
 212       if (ColumnNo != -1)
 213         S << ':' << (ColumnNo+1);
 214     }
 215     S << ": ";
 216   }
 217
 218   S << Message << '\n';
 219
 220   if (LineNo != -1 && ColumnNo != -1 && ShowLine) {
 221     S << LineContents << '\n';
 222
 223     // Print out spaces/tabs before the caret.
 224     for (unsigned i = 0; i != unsigned(ColumnNo); ++i)
 225       S << (LineContents[i] == '\t' ? '\t' : ' ');
 226     S << "^\n";
 227   }
 228 }
 229
 230