path: root/lib/Frontend/TextDiagnosticPrinter.cpp

//===--- TextDiagnosticPrinter.cpp - Diagnostic Printer -------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This diagnostic client prints out their diagnostic messages.
//
//===----------------------------------------------------------------------===//

#include "clang/Frontend/TextDiagnosticPrinter.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Lex/Lexer.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/ADT/SmallString.h"
#include <algorithm>
using namespace clang;

/// \brief Number of spaces to indent when word-wrapping.
const unsigned WordWrapIndentation = 6;

void TextDiagnosticPrinter::
PrintIncludeStack(SourceLocation Loc, const SourceManager &SM) {
  if (Loc.isInvalid()) return;

  PresumedLoc PLoc = SM.getPresumedLoc(Loc);

  // Print out the other include frames first.
  PrintIncludeStack(PLoc.getIncludeLoc(), SM);

  if (ShowLocation)
    OS << "In file included from " << PLoc.getFilename()
       << ':' << PLoc.getLine() << ":\n";
  else
    OS << "In included file:\n";
}

/// HighlightRange - Given a SourceRange and a line number, highlight (with ~'s)
/// any characters in LineNo that intersect the SourceRange.
void TextDiagnosticPrinter::HighlightRange(const SourceRange &R,
                                           const SourceManager &SM,
                                           unsigned LineNo, FileID FID,
                                           std::string &CaretLine,
                                           const std::string &SourceLine) {
  assert(CaretLine.size() == SourceLine.size() &&
         "Expect a correspondence between source and caret line!");
  if (!R.isValid()) return;

  SourceLocation Begin = SM.getInstantiationLoc(R.getBegin());
  SourceLocation End = SM.getInstantiationLoc(R.getEnd());
  
  // If the End location and the start location are the same and are a macro
  // location, then the range was something that came from a macro expansion
  // or _Pragma.  If this is an object-like macro, the best we can do is to
  // highlight the range.  If this is a function-like macro, we'd also like to
  // highlight the arguments.
  if (Begin == End && R.getEnd().isMacroID())
    End = SM.getInstantiationRange(R.getEnd()).second;
  
  unsigned StartLineNo = SM.getInstantiationLineNumber(Begin);
  if (StartLineNo > LineNo || SM.getFileID(Begin) != FID)
    return;  // No intersection.
  
  unsigned EndLineNo = SM.getInstantiationLineNumber(End);
  if (EndLineNo < LineNo || SM.getFileID(End) != FID)
    return;  // No intersection.
  
  // Compute the column number of the start.
  unsigned StartColNo = 0;
  if (StartLineNo == LineNo) {
    StartColNo = SM.getInstantiationColumnNumber(Begin);
    if (StartColNo) --StartColNo;  // Zero base the col #.
  }

  // Pick the first non-whitespace column.
  while (StartColNo < SourceLine.size() &&
         (SourceLine[StartColNo] == ' ' || SourceLine[StartColNo] == '\t'))
    ++StartColNo;
  
  // Compute the column number of the end.
  unsigned EndColNo = CaretLine.size();
  if (EndLineNo == LineNo) {
    EndColNo = SM.getInstantiationColumnNumber(End);
    if (EndColNo) {
      --EndColNo;  // Zero base the col #.
      
      // Add in the length of the token, so that we cover multi-char tokens.
      EndColNo += Lexer::MeasureTokenLength(End, SM, *LangOpts);
    } else {
      EndColNo = CaretLine.size();
    }
  }
  
  // Pick the last non-whitespace column.
  if (EndColNo <= SourceLine.size())
    while (EndColNo-1 &&
           (SourceLine[EndColNo-1] == ' ' || SourceLine[EndColNo-1] == '\t'))
      --EndColNo;
  else
    EndColNo = SourceLine.size();
  
  // Fill the range with ~'s.
  assert(StartColNo <= EndColNo && "Invalid range!");
  for (unsigned i = StartColNo; i < EndColNo; ++i)
    CaretLine[i] = '~';
}

void TextDiagnosticPrinter::EmitCaretDiagnostic(SourceLocation Loc,
                                                SourceRange *Ranges,
                                                unsigned NumRanges,
                                                SourceManager &SM,
                                          const CodeModificationHint *Hints,
                                                unsigned NumHints,
                                                unsigned AvoidColumn) {
  assert(!Loc.isInvalid() && "must have a valid source location here");
  
  // We always emit diagnostics about the instantiation points, not the spelling
  // points.  This more closely correlates to what the user writes.
  if (!Loc.isFileID()) {
    SourceLocation OneLevelUp = SM.getImmediateInstantiationRange(Loc).first;
    EmitCaretDiagnostic(OneLevelUp, Ranges, NumRanges, SM, 0, 0, AvoidColumn);
    
    // Map the location through the macro.
    Loc = SM.getInstantiationLoc(SM.getImmediateSpellingLoc(Loc));

    // Map the ranges.
    for (unsigned i = 0; i != NumRanges; ++i) {
      SourceLocation S = Ranges[i].getBegin(), E = Ranges[i].getEnd();
      if (S.isMacroID())
        S = SM.getInstantiationLoc(SM.getImmediateSpellingLoc(S));
      if (E.isMacroID())
        E = SM.getInstantiationLoc(SM.getImmediateSpellingLoc(E));
      Ranges[i] = SourceRange(S, E);
    }
    
    if (ShowLocation) {
      // Emit the file/line/column that this expansion came from.
      OS << SM.getBufferName(Loc) << ':' << SM.getInstantiationLineNumber(Loc)
         << ':';
      if (ShowColumn)
        OS << SM.getInstantiationColumnNumber(Loc) << ':';
      OS << ' ';
    }
    OS << "note: instantiated from:\n";
    AvoidColumn = 0;
  }
  
  // Decompose the location into a FID/Offset pair.
  std::pair<FileID, unsigned> LocInfo = SM.getDecomposedLoc(Loc);
  FileID FID = LocInfo.first;
  unsigned FileOffset = LocInfo.second;
  
  // Get information about the buffer it points into.
  std::pair<const char*, const char*> BufferInfo = SM.getBufferData(FID);
  const char *BufStart = BufferInfo.first;

  unsigned ColNo = SM.getColumnNumber(FID, FileOffset);
  
  // Rewind from the current position to the start of the line.
  const char *TokPtr = BufStart+FileOffset;
  const char *LineStart = TokPtr-ColNo+1; // Column # is 1-based.
  
  
  // Compute the line end.  Scan forward from the error position to the end of
  // the line.
  const char *LineEnd = TokPtr;
  while (*LineEnd != '\n' && *LineEnd != '\r' && *LineEnd != '\0')
    ++LineEnd;
  
  // Copy the line of code into an std::string for ease of manipulation.
  std::string SourceLine(LineStart, LineEnd);
  
  // Create a line for the caret that is filled with spaces that is the same
  // length as the line of source code.
  std::string CaretLine(LineEnd-LineStart, ' ');
  
  // Highlight all of the characters covered by Ranges with ~ characters.
  if (NumRanges) {
    unsigned LineNo = SM.getLineNumber(FID, FileOffset);
    
    for (unsigned i = 0, e = NumRanges;