//===- SourceMgr.cpp - Manager for Simple Source Buffers & Diagnostics ----===//

//

//                     The LLVM Compiler Infrastructure

//

// This file is distributed under the University of Illinois Open Source

// License. See LICENSE.TXT for details.

//

//===----------------------------------------------------------------------===//

//

// This file implements the SourceMgr class.  This class is used as a simple

// substrate for diagnostics, #include handling, and other low level things for

// simple parsers.

//

//===----------------------------------------------------------------------===//

#include "llvm/Support/SourceMgr.h"

#include "llvm/ADT/Twine.h"

#include "llvm/Support/MemoryBuffer.h"

#include "llvm/Support/Path.h"

#include "llvm/Support/raw_ostream.h"

using namespace llvm_ks;

static const size_t TabStop = 8;

namespace {

  struct LineNoCacheTy {

    unsigned LastQueryBufferID;

    const char *LastQuery;

    unsigned LineNoOfQuery;

  };

}

static LineNoCacheTy *getCache(void *Ptr) {

  return (LineNoCacheTy*)Ptr;

}

SourceMgr::~SourceMgr() {

  // Delete the line # cache if allocated.

  if (LineNoCacheTy *Cache = getCache(LineNoCache))

    delete Cache;

}

unsigned SourceMgr::AddIncludeFile(const std::string &Filename,

                                   SMLoc IncludeLoc,

                                   std::string &IncludedFile) {

  IncludedFile = Filename;

  ErrorOr<std::unique_ptr<MemoryBuffer>> NewBufOrErr =

    MemoryBuffer::getFile(IncludedFile);

  // If the file didn't exist directly, see if it's in an include path.

  for (unsigned i = 0, e = IncludeDirectories.size(); i != e && !NewBufOrErr;

       ++i) {

    IncludedFile =

        IncludeDirectories[i] + sys::path::get_separator().data() + Filename;

    NewBufOrErr = MemoryBuffer::getFile(IncludedFile);

  }

  if (!NewBufOrErr)

    return 0;

  return AddNewSourceBuffer(std::move(*NewBufOrErr), IncludeLoc);

}

unsigned SourceMgr::FindBufferContainingLoc(SMLoc Loc) const {

  for (unsigned i = 0, e = Buffers.size(); i != e; ++i)

    if (Loc.getPointer() >= Buffers[i].Buffer->getBufferStart() &&

        // Use <= here so that a pointer to the null at the end of the buffer

        // is included as part of the buffer.

        Loc.getPointer() <= Buffers[i].Buffer->getBufferEnd())

      return i + 1;

  return 0;

}

std::pair<unsigned, unsigned>

SourceMgr::getLineAndColumn(SMLoc Loc, unsigned BufferID) const {

  if (!BufferID)

    BufferID = FindBufferContainingLoc(Loc);

  assert(BufferID && "Invalid Location!");

  const MemoryBuffer *Buff = getMemoryBuffer(BufferID);

  // Count the number of \n's between the start of the file and the specified

  // location.

  unsigned LineNo = 1;

  const char *BufStart = Buff->getBufferStart();

  const char *Ptr = BufStart;

  // If we have a line number cache, and if the query is to a later point in the

  // same file, start searching from the last query location.  This optimizes

  // for the case when multiple diagnostics come out of one file in order.

  if (LineNoCacheTy *Cache = getCache(LineNoCache))

    if (Cache->LastQueryBufferID == BufferID &&

        Cache->LastQuery <= Loc.getPointer()) {

      Ptr = Cache->LastQuery;

      LineNo = Cache->LineNoOfQuery;

    }

  // Scan for the location being queried, keeping track of the number of lines

  // we see.

  for (; SMLoc::getFromPointer(Ptr) != Loc; ++Ptr)

    if (*Ptr == '\n') ++LineNo;

  // Allocate the line number cache if it doesn't exist.

  if (!LineNoCache)

    LineNoCache = new LineNoCacheTy();

  // Update the line # cache.

  LineNoCacheTy &Cache = *getCache(LineNoCache);

  Cache.LastQueryBufferID = BufferID;

  Cache.LastQuery = Ptr;

  Cache.LineNoOfQuery = LineNo;

  size_t NewlineOffs = StringRef(BufStart, Ptr-BufStart).find_last_of("\n\r");

  if (NewlineOffs == StringRef::npos) NewlineOffs = ~(size_t)0;

  return std::make_pair(LineNo, Ptr-BufStart-NewlineOffs);

}

void SourceMgr::PrintIncludeStack(SMLoc IncludeLoc, raw_ostream &OS) const {

  if (IncludeLoc == SMLoc()) return;  // Top of stack.

  unsigned CurBuf = FindBufferContainingLoc(IncludeLoc);

  assert(CurBuf && "Invalid or unspecified location!");

  PrintIncludeStack(getBufferInfo(CurBuf).IncludeLoc, OS);

  OS << "Included from "

     << getBufferInfo(CurBuf).Buffer->getBufferIdentifier()

     << ":" << FindLineNumber(IncludeLoc, CurBuf) << ":\n";

}

SMDiagnostic SourceMgr::GetMessage(SMLoc Loc, SourceMgr::DiagKind Kind,

                                   const Twine &Msg,

                                   ArrayRef<SMRange> Ranges,

                                   ArrayRef<SMFixIt> FixIts) const {

  // First thing to do: find the current buffer containing the specified

  // location to pull out the source line.

  SmallVector<std::pair<unsigned, unsigned>, 4> ColRanges;

  std::pair<unsigned, unsigned> LineAndCol;

  const char *BufferID = "<unknown>";

  std::string LineStr;

  if (Loc.isValid()) {

    unsigned CurBuf = FindBufferContainingLoc(Loc);

    assert(CurBuf && "Invalid or unspecified location!");

    const MemoryBuffer *CurMB = getMemoryBuffer(CurBuf);

    BufferID = CurMB->getBufferIdentifier();

    // Scan backward to find the start of the line.

    const char *LineStart = Loc.getPointer();

    const char *BufStart = CurMB->getBufferStart();

    while (LineStart != BufStart && LineStart[-1] != '\n' &&

           LineStart[-1] != '\r')

      --LineStart;

    // Get the end of the line.

    const char *LineEnd = Loc.getPointer();

    const char *BufEnd = CurMB->getBufferEnd();

    while (LineEnd != BufEnd && LineEnd[0] != '\n' && LineEnd[0] != '\r')

      ++LineEnd;

    LineStr = std::string(LineStart, LineEnd);

    // Convert any ranges to column ranges that only intersect the line of the

    // location.

    for (unsigned i = 0, e = Ranges.size(); i != e; ++i) {

      SMRange R = Ranges[i];

      if (!R.isValid()) continue;

      // If the line doesn't contain any part of the range, then ignore it.

      if (R.Start.getPointer() > LineEnd || R.End.getPointer() < LineStart)

        continue;

      // Ignore pieces of the range that go onto other lines.

      if (R.Start.getPointer() < LineStart)

        R.Start = SMLoc::getFromPointer(LineStart);

      if (R.End.getPointer() > LineEnd)

        R.End = SMLoc::getFromPointer(LineEnd);

      // Translate from SMLoc ranges to column ranges.

      // FIXME: Handle multibyte characters.

      ColRanges.push_back(std::make_pair(R.Start.getPointer()-LineStart,

                                         R.End.getPointer()-LineStart));

    }

    LineAndCol = getLineAndColumn(Loc, CurBuf);

  }

  return SMDiagnostic(*this, Loc, BufferID, LineAndCol.first,

                      LineAndCol.second-1, Kind, Msg.str(),

                      LineStr, ColRanges, FixIts);

}

void SourceMgr::PrintMessage(raw_ostream &OS, const SMDiagnostic &Diagnostic,

                             bool ShowColors) const {

  // Report the message with the diagnostic handler if present.

  if (DiagHandler) {

    DiagHandler(Diagnostic, DiagContext);

    return;

  }

  if (Diagnostic.getLoc().isValid()) {

    unsigned CurBuf = FindBufferContainingLoc(Diagnostic.getLoc());

    assert(CurBuf && "Invalid or unspecified location!");

    PrintIncludeStack(getBufferInfo(CurBuf).IncludeLoc, OS);

  }

  Diagnostic.print(nullptr, OS, ShowColors);

}

void SourceMgr::PrintMessage(raw_ostream &OS, SMLoc Loc,

                             SourceMgr::DiagKind Kind,

                             const Twine &Msg, ArrayRef<SMRange> Ranges,

                             ArrayRef<SMFixIt> FixIts, bool ShowColors) const {

  PrintMessage(OS, GetMessage(Loc, Kind, Msg, Ranges, FixIts), ShowColors);

}

void SourceMgr::PrintMessage(SMLoc Loc, SourceMgr::DiagKind Kind,

                             const Twine &Msg, ArrayRef<SMRange> Ranges,

                             ArrayRef<SMFixIt> FixIts, bool ShowColors) const {

  PrintMessage(llvm_ks::errs(), Loc, Kind, Msg, Ranges, FixIts, ShowColors);

}

//===----------------------------------------------------------------------===//

// SMDiagnostic Implementation

//===----------------------------------------------------------------------===//

SMDiagnostic::SMDiagnostic(const SourceMgr &sm, SMLoc L, StringRef FN,

                           int Line, int Col, SourceMgr::DiagKind Kind,

                           StringRef Msg, StringRef LineStr,

                           ArrayRef<std::pair<unsigned,unsigned> > Ranges,

                           ArrayRef<SMFixIt> Hints)

  : SM(&sm), Loc(L), Filename(FN), LineNo(Line), ColumnNo(Col), Kind(Kind),

    Message(Msg), LineContents(LineStr), Ranges(Ranges.vec()),

    FixIts(Hints.begin(), Hints.end()) {

  std::sort(FixIts.begin(), FixIts.end());

}

static void buildFixItLine(std::string &CaretLine, std::string &FixItLine,

                           ArrayRef<SMFixIt> FixIts, ArrayRef<char> SourceLine){

  if (FixIts.empty())

    return;

  const char *LineStart = SourceLine.begin();

  const char *LineEnd = SourceLine.end();

  size_t PrevHintEndCol = 0;

  for (ArrayRef<SMFixIt>::iterator I = FixIts.begin(), E = FixIts.end();

       I != E; ++I) {

    // If the fixit contains a newline or tab, ignore it.

    if (I->getText().find_first_of("\n\r\t") != StringRef::npos)

      continue;

    SMRange R = I->getRange();

    // If the line doesn't contain any part of the range, then ignore it.

    if (R.Start.getPointer() > LineEnd || R.End.getPointer() < LineStart)

      continue;

    // Translate from SMLoc to column.

    // Ignore pieces of the range that go onto other lines.

    // FIXME: Handle multibyte characters in the source line.

    unsigned FirstCol;

    if (R.Start.getPointer() < LineStart)

      FirstCol = 0;

    else

      FirstCol = R.Start.getPointer() - LineStart;

    // If we inserted a long previous hint, push this one forwards, and add

    // an extra space to show that this is not part of the previous

    // completion. This is sort of the best we can do when two hints appear

    // to overlap.

    //

    // Note that if this hint is located immediately after the previous

    // hint, no space will be added, since the location is more important.

    unsigned HintCol = FirstCol;

    if (HintCol < PrevHintEndCol)

      HintCol = PrevHintEndCol + 1;

    // This relies on one byte per column in our fixit hints.

    unsigned LastColumnModified = HintCol + I->getText().size();

    if (LastColumnModified > FixItLine.size())

      FixItLine.resize(LastColumnModified, ' ');

    std::copy(I->getText().begin(), I->getText().end(),

              FixItLine.begin() + HintCol);

    PrevHintEndCol = LastColumnModified;

    // For replacements, mark the removal range with '~'.

    // FIXME: Handle multibyte characters in the source line.

    unsigned LastCol;

    if (R.End.getPointer() >= LineEnd)

      LastCol = LineEnd - LineStart;

    else

      LastCol = R.End.getPointer() - LineStart;

    std::fill(&CaretLine[FirstCol], &CaretLine[LastCol], '~');

  }

}

static void printSourceLine(raw_ostream &S, StringRef LineContents) {

  // Print out the source line one character at a time, so we can expand tabs.

  for (unsigned i = 0, e = LineContents.size(), OutCol = 0; i != e; ++i) {

    if (LineContents[i] != '\t') {

      S << LineContents[i];

      ++OutCol;

      continue;

    }

    // If we have a tab, emit at least one space, then round up to 8 columns.

    do {

      S << ' ';

      ++OutCol;

    } while ((OutCol % TabStop) != 0);

  }

  S << '\n';

}

static bool isNonASCII(char c) {

  return c & 0x80;

}

void SMDiagnostic::print(const char *ProgName, raw_ostream &S, bool ShowColors,

                         bool ShowKindLabel) const {

  // Display colors only if OS supports colors.

  ShowColors &= S.has_colors();

  if (ShowColors)

    S.changeColor(raw_ostream::SAVEDCOLOR, true);

  if (ProgName && ProgName[0])

    S << ProgName << ": ";

  if (!Filename.empty()) {

    if (Filename == "-")

      S << "<stdin>";

    else

      S << Filename;

    if (LineNo != -1) {

      S << ':' << LineNo;

      if (ColumnNo != -1)

        S << ':' << (ColumnNo+1);

    }

    S << ": ";

  }

  if (ShowKindLabel) {

    switch (Kind) {

    case SourceMgr::DK_Error:

      if (ShowColors)

        S.changeColor(raw_ostream::RED, true);

      S << "error: ";

      break;

    case SourceMgr::DK_Warning:

      if (ShowColors)

        S.changeColor(raw_ostream::MAGENTA, true);

      S << "warning: ";

      break;

    case SourceMgr::DK_Note:

      if (ShowColors)

        S.changeColor(raw_ostream::BLACK, true);

      S << "note: ";

      break;

    }

    if (ShowColors) {

      S.resetColor();

      S.changeColor(raw_ostream::SAVEDCOLOR, true);

    }

  }

  S << Message << '\n';

  if (ShowColors)

    S.resetColor();

  if (LineNo == -1 || ColumnNo == -1)

    return;

  // FIXME: If there are multibyte or multi-column characters in the source, all

  // our ranges will be wrong. To do this properly, we'll need a byte-to-column

  // map like Clang's TextDiagnostic. For now, we'll just handle tabs by

  // expanding them later, and bail out rather than show incorrect ranges and

  // misaligned fixits for any other odd characters.

  if (std::find_if(LineContents.begin(), LineContents.end(), isNonASCII) !=

      LineContents.end()) {

    printSourceLine(S, LineContents);

    return;

  }

  size_t NumColumns = LineContents.size();

  // Build the line with the caret and ranges.

  std::string CaretLine(NumColumns+1, ' ');

  // Expand any ranges.

  for (unsigned r = 0, e = Ranges.size(); r != e; ++r) {

    std::pair<unsigned, unsigned> R = Ranges[r];

    std::fill(&CaretLine[R.first],

              &CaretLine[std::min((size_t)R.second, CaretLine.size())],

              '~');

  }

  // Add any fix-its.

  // FIXME: Find the beginning of the line properly for multibyte characters.

  std::string FixItInsertionLine;

  buildFixItLine(CaretLine, FixItInsertionLine, FixIts,

                 makeArrayRef(Loc.getPointer() - ColumnNo,

                              LineContents.size()));

  // Finally, plop on the caret.

  if (unsigned(ColumnNo) <= NumColumns)

    CaretLine[ColumnNo] = '^';

  else 

    CaretLine[NumColumns] = '^';

  // ... and remove trailing whitespace so the output doesn't wrap for it.  We

  // know that the line isn't completely empty because it has the caret in it at

  // least.

  CaretLine.erase(CaretLine.find_last_not_of(' ')+1);

  printSourceLine(S, LineContents);

  if (ShowColors)

    S.changeColor(raw_ostream::GREEN, true);

  // Print out the caret line, matching tabs in the source line.

  for (unsigned i = 0, e = CaretLine.size(), OutCol = 0; i != e; ++i) {

    if (i >= LineContents.size() || LineContents[i] != '\t') {

      S << CaretLine[i];

      ++OutCol;

      continue;

    }

    // Okay, we have a tab.  Insert the appropriate number of characters.

    do {

      S << CaretLine[i];

      ++OutCol;

    } while ((OutCol % TabStop) != 0);

  }

  S << '\n';

  if (ShowColors)

    S.resetColor();

  // Print out the replacement line, matching tabs in the source line.

  if (FixItInsertionLine.empty())

    return;

  for (size_t i = 0, e = FixItInsertionLine.size(), OutCol = 0; i < e; ++i) {

    if (i >= LineContents.size() || LineContents[i] != '\t') {

      S << FixItInsertionLine[i];

      ++OutCol;

      continue;

    }

    // Okay, we have a tab.  Insert the appropriate number of characters.

    do {

      S << FixItInsertionLine[i];

      // FIXME: This is trying not to break up replacements, but then to re-sync

      // with the tabs between replacements. This will fail, though, if two

      // fix-it replacements are exactly adjacent, or if a fix-it contains a

      // space. Really we should be precomputing column widths, which we'll

      // need anyway for multibyte chars.

      if (FixItInsertionLine[i] != ' ')

        ++i;

      ++OutCol;

    } while (((OutCol % TabStop) != 0) && i != e);

  }

  S << '\n';

}