llvm/lib/Support/SourceMgr.cpp - toolchain/llvm-project - Gitiles

 //===- 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/ADT/ArrayRef.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/Support/ErrorOr.h"
 #include "llvm/Support/Locale.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/SMLoc.h"
 #include "llvm/Support/SourceMgr.h"
 #include <algorithm>
 #include <cassert>
 #include <cstddef>
 #include <memory>
 #include <string>
 #include <utility>

 using namespace llvm;

 static const size_t TabStop = 8;

 namespace {

   struct LineNoCacheTy {
     const char *LastQuery;
     unsigned LastQueryBufferID;
     unsigned LineNoOfQuery;
   };

 } // end anonymous namespace

 static LineNoCacheTy *getCache(void *Ptr) {
   return (LineNoCacheTy*)Ptr;
 }

 SourceMgr::~SourceMgr() {
   delete getCache(LineNoCache);
 }

 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;
   StringRef 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(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;

     // FIXME: This assertion is intended to catch unintended use of multibyte
     // characters in fixits. If we decide to do this, we'll have to track
     // separate byte widths for the source and fixit lines.
     assert((size_t)sys::locale::columnWidth(I->getText()) ==
            I->getText().size());

     // 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 (find_if(LineContents, 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';
 }
	//===- 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/ADT/ArrayRef.h"
	#include "llvm/ADT/SmallVector.h"
	#include "llvm/ADT/STLExtras.h"
	#include "llvm/ADT/StringRef.h"
	#include "llvm/ADT/Twine.h"
	#include "llvm/Support/ErrorOr.h"
	#include "llvm/Support/Locale.h"
	#include "llvm/Support/MemoryBuffer.h"
	#include "llvm/Support/Path.h"
	#include "llvm/Support/raw_ostream.h"
	#include "llvm/Support/SMLoc.h"
	#include "llvm/Support/SourceMgr.h"
	#include <algorithm>
	#include <cassert>
	#include <cstddef>
	#include <memory>
	#include <string>
	#include <utility>

	using namespace llvm;

	static const size_t TabStop = 8;

	namespace {

	struct LineNoCacheTy {
	const char *LastQuery;
	unsigned LastQueryBufferID;
	unsigned LineNoOfQuery;
	};

	} // end anonymous namespace

	static LineNoCacheTy getCache(void Ptr) {
	return (LineNoCacheTy*)Ptr;
	}

	SourceMgr::~SourceMgr() {
	delete getCache(LineNoCache);
	}

	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;
	StringRef 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(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;

	// FIXME: This assertion is intended to catch unintended use of multibyte
	// characters in fixits. If we decide to do this, we'll have to track
	// separate byte widths for the source and fixit lines.
	assert((size_t)sys::locale::columnWidth(I->getText()) ==
	I->getText().size());

	// 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 (find_if(LineContents, 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';
	}