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