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