utils/TableGen/TGSourceMgr.cpp

   1 //===- TGSourceMgr.cpp - Manager for 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 TGSourceMgr class.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "TGSourceMgr.h"
  15 #include "llvm/Support/MemoryBuffer.h"
  16 #include "llvm/Support/raw_ostream.h"
  17 using namespace llvm;
  18
  19 TGSourceMgr::~TGSourceMgr() {
  20   while (!Buffers.empty()) {
  21     delete Buffers.back().Buffer;
  22     Buffers.pop_back();
  23   }
  24 }
  25
  26 /// FindBufferContainingLoc - Return the ID of the buffer containing the
  27 /// specified location, returning -1 if not found.
  28 int TGSourceMgr::FindBufferContainingLoc(TGLoc Loc) const {
  29   for (unsigned i = 0, e = Buffers.size(); i != e; ++i)
  30     if (Loc.getPointer() >= Buffers[i].Buffer->getBufferStart() &&
  31         // Use <= here so that a pointer to the null at the end of the buffer
  32         // is included as part of the buffer.
  33         Loc.getPointer() <= Buffers[i].Buffer->getBufferEnd())
  34       return i;
  35   return -1;
  36 }
  37
  38 /// FindLineNumber - Find the line number for the specified location in the
  39 /// specified file.  This is not a fast method.
  40 unsigned TGSourceMgr::FindLineNumber(TGLoc Loc, int BufferID) const {
  41   if (BufferID == -1) BufferID = FindBufferContainingLoc(Loc);
  42   assert(BufferID != -1 && "Invalid Location!");
  43
  44   MemoryBuffer *Buff = getBufferInfo(BufferID).Buffer;
  45
  46   // Count the number of \n's between the start of the file and the specified
  47   // location.
  48   unsigned LineNo = 1;
  49
  50   const char *Ptr = Buff->getBufferStart();
  51
  52   for (; TGLoc::getFromPointer(Ptr) != Loc; ++Ptr)
  53     if (*Ptr == '\n') ++LineNo;
  54   return LineNo;
  55 }
  56
  57 void TGSourceMgr::PrintIncludeStack(TGLoc IncludeLoc) const {
  58   if (IncludeLoc == TGLoc()) return;  // Top of stack.
  59
  60   int CurBuf = FindBufferContainingLoc(IncludeLoc);
  61   assert(CurBuf != -1 && "Invalid or unspecified location!");
  62
  63   PrintIncludeStack(getBufferInfo(CurBuf).IncludeLoc);
  64
  65   errs() << "Included from "
  66          << getBufferInfo(CurBuf).Buffer->getBufferIdentifier()
  67          << ":" << FindLineNumber(IncludeLoc, CurBuf) << ":\n";
  68 }
  69
  70
  71 void TGSourceMgr::PrintError(TGLoc ErrorLoc, const std::string &Msg) const {
  72   raw_ostream &OS = errs();
  73
  74   // First thing to do: find the current buffer containing the specified
  75   // location.
  76   int CurBuf = FindBufferContainingLoc(ErrorLoc);
  77   assert(CurBuf != -1 && "Invalid or unspecified location!");
  78
  79   PrintIncludeStack(getBufferInfo(CurBuf).IncludeLoc);
  80
  81   MemoryBuffer *CurMB = getBufferInfo(CurBuf).Buffer;
  82
  83
  84   OS << "Parsing " << CurMB->getBufferIdentifier() << ":"
  85      << FindLineNumber(ErrorLoc, CurBuf) << ": ";
  86
  87   OS << Msg << "\n";
  88
  89   // Scan backward to find the start of the line.
  90   const char *LineStart = ErrorLoc.getPointer();
  91   while (LineStart != CurMB->getBufferStart() &&
  92          LineStart[-1] != '\n' && LineStart[-1] != '\r')
  93     --LineStart;
  94   // Get the end of the line.
  95   const char *LineEnd = ErrorLoc.getPointer();
  96   while (LineEnd != CurMB->getBufferEnd() &&
  97          LineEnd[0] != '\n' && LineEnd[0] != '\r')
  98     ++LineEnd;
  99   // Print out the line.
 100   OS << std::string(LineStart, LineEnd) << "\n";
 101   // Print out spaces before the caret.
 102   for (const char *Pos = LineStart; Pos != ErrorLoc.getPointer(); ++Pos)
 103     OS << (*Pos == '\t' ? '\t' : ' ');
 104   OS << "^\n";
 105 }