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                                    std::string &IncludedFile) {
  54   OwningPtr<MemoryBuffer> NewBuf;
  55   IncludedFile = Filename;
  56   MemoryBuffer::getFile(IncludedFile.c_str(), NewBuf);
  57
  58   // If the file didn't exist directly, see if it's in an include path.
  59   for (unsigned i = 0, e = IncludeDirectories.size(); i != e && !NewBuf; ++i) {
  60     IncludedFile = IncludeDirectories[i] + "/" + Filename;
  61     MemoryBuffer::getFile(IncludedFile.c_str(), NewBuf);
  62   }
  63
  64   if (NewBuf == 0) return ~0U;
  65
  66   return AddNewSourceBuffer(NewBuf.take(), IncludeLoc);
  67 }
  68
  69
  70 /// FindBufferContainingLoc - Return the ID of the buffer containing the
  71 /// specified location, returning -1 if not found.
  72 int SourceMgr::FindBufferContainingLoc(SMLoc Loc) const {
  73   for (unsigned i = 0, e = Buffers.size(); i != e; ++i)
  74     if (Loc.getPointer() >= Buffers[i].Buffer->getBufferStart() &&
  75         // Use <= here so that a pointer to the null at the end of the buffer
  76         // is included as part of the buffer.
  77         Loc.getPointer() <= Buffers[i].Buffer->getBufferEnd())
  78       return i;
  79   return -1;
  80 }
  81
  82 /// FindLineNumber - Find the line number for the specified location in the
  83 /// specified file.  This is not a fast method.
  84 unsigned SourceMgr::FindLineNumber(SMLoc Loc, int BufferID) const {
  85   if (BufferID == -1) BufferID = FindBufferContainingLoc(Loc);
  86   assert(BufferID != -1 && "Invalid Location!");
  87
  88   MemoryBuffer *Buff = getBufferInfo(BufferID).Buffer;
  89
  90   // Count the number of \n's between the start of the file and the specified
  91   // location.
  92   unsigned LineNo = 1;
  93
  94   const char *Ptr = Buff->getBufferStart();
  95
  96   // If we have a line number cache, and if the query is to a later point in the
  97   // same file, start searching from the last query location.  This optimizes
  98   // for the case when multiple diagnostics come out of one file in order.
  99   if (LineNoCacheTy *Cache = getCache(LineNoCache))
 100     if (Cache->LastQueryBufferID == BufferID &&
 101         Cache->LastQuery <= Loc.getPointer()) {
 102       Ptr = Cache->LastQuery;
 103       LineNo = Cache->LineNoOfQuery;
 104     }
 105
 106   // Scan for the location being queried, keeping track of the number of lines
 107   // we see.
 108   for (; SMLoc::getFromPointer(Ptr) != Loc; ++Ptr)
 109     if (*Ptr == '\n') ++LineNo;
 110
 111
 112   // Allocate the line number cache if it doesn't exist.
 113   if (LineNoCache == 0)
 114     LineNoCache = new LineNoCacheTy();
 115
 116   // Update the line # cache.
 117   LineNoCacheTy &Cache = *getCache(LineNoCache);
 118   Cache.LastQueryBufferID = BufferID;
 119   Cache.LastQuery = Ptr;
 120   Cache.LineNoOfQuery = LineNo;
 121   return LineNo;
 122 }
 123
 124 void SourceMgr::PrintIncludeStack(SMLoc IncludeLoc, raw_ostream &OS) const {
 125   if (IncludeLoc == SMLoc()) return;  // Top of stack.
 126
 127   int CurBuf = FindBufferContainingLoc(IncludeLoc);
 128   assert(CurBuf != -1 && "Invalid or unspecified location!");
 129
 130   PrintIncludeStack(getBufferInfo(CurBuf).IncludeLoc, OS);
 131
 132   OS << "Included from "
 133      << getBufferInfo(CurBuf).Buffer->getBufferIdentifier()
 134      << ":" << FindLineNumber(IncludeLoc, CurBuf) << ":\n";
 135 }
 136
 137
 138 /// GetMessage - Return an SMDiagnostic at the specified location with the
 139 /// specified string.
 140 ///
 141 /// @param Type - If non-null, the kind of message (e.g., "error") which is
 142 /// prefixed to the message.
 143 SMDiagnostic SourceMgr::GetMessage(SMLoc Loc, const Twine &Msg,
 144                                    const char *Type, bool ShowLine) const {
 145
 146   // First thing to do: find the current buffer containing the specified
 147   // location.
 148   int CurBuf = FindBufferContainingLoc(Loc);
 149   assert(CurBuf != -1 && "Invalid or unspecified location!");
 150
 151   MemoryBuffer *CurMB = getBufferInfo(CurBuf).Buffer;
 152
 153   // Scan backward to find the start of the line.
 154   const char *LineStart = Loc.getPointer();
 155   while (LineStart != CurMB->getBufferStart() &&
 156          LineStart[-1] != '\n' && LineStart[-1] != '\r')
 157     --LineStart;
 158
 159   std::string LineStr;
 160   if (ShowLine) {
 161     // Get the end of the line.
 162     const char *LineEnd = Loc.getPointer();
 163     while (LineEnd != CurMB->getBufferEnd() &&
 164            LineEnd[0] != '\n' && LineEnd[0] != '\r')
 165       ++LineEnd;
 166     LineStr = std::string(LineStart, LineEnd);
 167   }
 168
 169   std::string PrintedMsg;
 170   raw_string_ostream OS(PrintedMsg);
 171   if (Type)
 172     OS << Type << ": ";
 173   OS << Msg;
 174
 175   return SMDiagnostic(*this, Loc,
 176                       CurMB->getBufferIdentifier(), FindLineNumber(Loc, CurBuf),
 177                       Loc.getPointer()-LineStart, OS.str(),
 178                       LineStr, ShowLine);
 179 }
 180
 181 void SourceMgr::PrintMessage(SMLoc Loc, const Twine &Msg,
 182                              const char *Type, bool ShowLine) const {
 183   // Report the message with the diagnostic handler if present.
 184   if (DiagHandler) {
 185     DiagHandler(GetMessage(Loc, Msg, Type, ShowLine), DiagContext);
 186     return;
 187   }
 188
 189   raw_ostream &OS = errs();
 190
 191   int CurBuf = FindBufferContainingLoc(Loc);
 192   assert(CurBuf != -1 && "Invalid or unspecified location!");
 193   PrintIncludeStack(getBufferInfo(CurBuf).IncludeLoc, OS);
 194
 195   GetMessage(Loc, Msg, Type, ShowLine).Print(0, OS);
 196 }
 197
 198 //===----------------------------------------------------------------------===//
 199 // SMDiagnostic Implementation
 200 //===----------------------------------------------------------------------===//
 201
 202 void SMDiagnostic::Print(const char *ProgName, raw_ostream &S) const {
 203   if (ProgName && ProgName[0])
 204     S << ProgName << ": ";
 205
 206   if (!Filename.empty()) {
 207     if (Filename == "-")
 208       S << "<stdin>";
 209     else
 210       S << Filename;
 211
 212     if (LineNo != -1) {
 213       S << ':' << LineNo;
 214       if (ColumnNo != -1)
 215         S << ':' << (ColumnNo+1);
 216     }
 217     S << ": ";
 218   }
 219
 220   S << Message << '\n';
 221
 222   if (LineNo != -1 && ColumnNo != -1 && ShowLine) {
 223     S << LineContents << '\n';
 224
 225     // Print out spaces/tabs before the caret.
 226     for (unsigned i = 0; i != unsigned(ColumnNo); ++i)
 227       S << (LineContents[i] == '\t' ? '\t' : ' ');
 228     S << "^\n";
 229   }
 230 }
 231
 232