SourceMgr.cpp revision 7ee5d5f97b3fa709038ff7fd640dc775efaadc26 
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/Support/SourceMgr.h"
17#include "llvm/Support/MemoryBuffer.h"
18#include "llvm/Support/raw_ostream.h"
19using namespace llvm;
20
21SourceMgr::~SourceMgr() {
22  while (!Buffers.empty()) {
23    delete Buffers.back().Buffer;
24    Buffers.pop_back();
25  }
26}
27
28/// AddIncludeFile - Search for a file with the specified name in the current
29/// directory or in one of the IncludeDirs.  If no file is found, this returns
30/// ~0, otherwise it returns the buffer ID of the stacked file.
31unsigned SourceMgr::AddIncludeFile(const std::string &Filename,
32                                   SMLoc IncludeLoc) {
33
34  MemoryBuffer *NewBuf = MemoryBuffer::getFile(Filename.c_str());
35
36  // If the file didn't exist directly, see if it's in an include path.
37  for (unsigned i = 0, e = IncludeDirectories.size(); i != e && !NewBuf; ++i) {
38    std::string IncFile = IncludeDirectories[i] + "/" + Filename;
39    NewBuf = MemoryBuffer::getFile(IncFile.c_str());
40  }
41
42  if (NewBuf == 0) return ~0U;
43
44  return AddNewSourceBuffer(NewBuf, IncludeLoc);
45}
46
47
48/// FindBufferContainingLoc - Return the ID of the buffer containing the
49/// specified location, returning -1 if not found.
50int SourceMgr::FindBufferContainingLoc(SMLoc Loc) const {
51  for (unsigned i = 0, e = Buffers.size(); i != e; ++i)
52    if (Loc.getPointer() >= Buffers[i].Buffer->getBufferStart() &&
53        // Use <= here so that a pointer to the null at the end of the buffer
54        // is included as part of the buffer.
55        Loc.getPointer() <= Buffers[i].Buffer->getBufferEnd())
56      return i;
57  return -1;
58}
59
60/// FindLineNumber - Find the line number for the specified location in the
61/// specified file.  This is not a fast method.
62unsigned SourceMgr::FindLineNumber(SMLoc Loc, int BufferID) const {
63  if (BufferID == -1) BufferID = FindBufferContainingLoc(Loc);
64  assert(BufferID != -1 && "Invalid Location!");
65
66  MemoryBuffer *Buff = getBufferInfo(BufferID).Buffer;
67
68  // Count the number of \n's between the start of the file and the specified
69  // location.
70  unsigned LineNo = 1;
71
72  const char *Ptr = Buff->getBufferStart();
73
74  for (; SMLoc::getFromPointer(Ptr) != Loc; ++Ptr)
75    if (*Ptr == '\n') ++LineNo;
76  return LineNo;
77}
78
79void SourceMgr::PrintIncludeStack(SMLoc IncludeLoc) const {
80  if (IncludeLoc == SMLoc()) return;  // Top of stack.
81
82  int CurBuf = FindBufferContainingLoc(IncludeLoc);
83  assert(CurBuf != -1 && "Invalid or unspecified location!");
84
85  PrintIncludeStack(getBufferInfo(CurBuf).IncludeLoc);
86
87  errs() << "Included from "
88         << getBufferInfo(CurBuf).Buffer->getBufferIdentifier()
89         << ":" << FindLineNumber(IncludeLoc, CurBuf) << ":\n";
90}
91
92
93void SourceMgr::PrintError(SMLoc ErrorLoc, const std::string &Msg) const {
94  raw_ostream &OS = errs();
95
96  // First thing to do: find the current buffer containing the specified
97  // location.
98  int CurBuf = FindBufferContainingLoc(ErrorLoc);
99  assert(CurBuf != -1 && "Invalid or unspecified location!");
100
101  PrintIncludeStack(getBufferInfo(CurBuf).IncludeLoc);
102
103  MemoryBuffer *CurMB = getBufferInfo(CurBuf).Buffer;
104
105
106  OS << "Parsing " << CurMB->getBufferIdentifier() << ":"
107     << FindLineNumber(ErrorLoc, CurBuf) << ": ";
108
109  OS << Msg << "\n";
110
111  // Scan backward to find the start of the line.
112  const char *LineStart = ErrorLoc.getPointer();
113  while (LineStart != CurMB->getBufferStart() &&
114         LineStart[-1] != '\n' && LineStart[-1] != '\r')
115    --LineStart;
116  // Get the end of the line.
117  const char *LineEnd = ErrorLoc.getPointer();
118  while (LineEnd != CurMB->getBufferEnd() &&
119         LineEnd[0] != '\n' && LineEnd[0] != '\r')
120    ++LineEnd;
121  // Print out the line.
122  OS << std::string(LineStart, LineEnd) << "\n";
123  // Print out spaces before the caret.
124  for (const char *Pos = LineStart; Pos != ErrorLoc.getPointer(); ++Pos)
125    OS << (*Pos == '\t' ? '\t' : ' ');
126  OS << "^\n";
127}
128