SourceLocation.h revision 9dc1f530c086d2c16f8cba758b0f59a5bf41323a 
1//===--- SourceLocation.h - Compact identifier for Source Files -*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by Chris Lattner and is distributed under
6// the University of Illinois Open Source License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10//  This file defines the SourceLocation class.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CLANG_SOURCELOCATION_H
15#define LLVM_CLANG_SOURCELOCATION_H
16
17#include <cassert>
18
19namespace clang {
20
21/// SourceLocation - This is a carefully crafted 32-bit identifier that encodes
22/// a full include stack, line and column number information for a position in
23/// an input translation unit.
24class SourceLocation {
25  unsigned ID;
26public:
27  enum {
28    FileIDBits  = 14,
29    FilePosBits = 32-1-FileIDBits,
30
31    MacroIDBits       = 23,
32    MacroPhysOffsBits = 5,
33    MacroLogOffBits   = 3
34  };
35
36  SourceLocation() : ID(0) {}  // 0 is an invalid FileID.
37
38  bool isFileID() const { return (ID >> 31) == 0; }
39  bool isMacroID() const { return (ID >> 31) != 0; }
40
41  static SourceLocation getFileLoc(unsigned FileID, unsigned FilePos) {
42    SourceLocation L;
43    // If a FilePos is larger than (1<<FilePosBits), the SourceManager makes
44    // enough consequtive FileIDs that we have one for each chunk.
45    if (FilePos >= (1 << FilePosBits)) {
46      FileID += FilePos >> FilePosBits;
47      FilePos &= (1 << FilePosBits)-1;
48    }
49
50    // FIXME: Find a way to handle out of FileID bits!  Maybe MaxFileID is an
51    // escape of some sort?
52    if (FileID >= (1 << FileIDBits))
53      FileID = (1 << FileIDBits)-1;
54
55    L.ID = (FileID << FilePosBits) | FilePos;
56    return L;
57  }
58
59  static SourceLocation getMacroLoc(unsigned MacroID, unsigned PhysOffs,
60                                    unsigned LogOffs) {
61    SourceLocation L;
62
63    assert(MacroID < (1 << MacroIDBits) && "Too many macros!");
64    assert(PhysOffs < (1 << MacroPhysOffsBits) && "Physoffs too large!");
65    assert(LogOffs  < (1 << MacroLogOffBits) && "Logical offs too large!");
66
67    L.ID = (1 << 31) | (MacroID << (MacroPhysOffsBits+MacroLogOffBits)) |
68           (PhysOffs << MacroLogOffBits) | LogOffs;
69    return L;
70  }
71
72
73  /// isValid - Return true if this is a valid SourceLocation object.  Invalid
74  /// SourceLocations are often used when events have no corresponding location
75  /// in the source (e.g. a diagnostic is required for a command line option).
76  ///
77  bool isValid() const { return ID != 0; }
78  bool isInvalid() const { return ID == 0; }
79
80  /// getFileID - Return the file identifier for this SourceLocation.  This
81  /// FileID can be used with the SourceManager object to obtain an entire
82  /// include stack for a file position reference.
83  unsigned getFileID() const {
84    assert(isFileID() && "can't get the file id of a non-file sloc!");
85    return ID >> FilePosBits;
86  }
87
88  /// getRawFilePos - Return the byte offset from the start of the file-chunk
89  /// referred to by FileID.  This method should not be used to get the offset
90  /// from the start of the file, instead you should use
91  /// SourceManager::getFilePos.  This method will be incorrect for large files.
92  unsigned getRawFilePos() const {
93    assert(isFileID() && "can't get the file id of a non-file sloc!");
94    return ID & ((1 << FilePosBits)-1);
95  }
96
97  unsigned getMacroID() const {
98    assert(isMacroID() && "Is not a macro id!");
99    return (ID >> (MacroPhysOffsBits+MacroLogOffBits)) & ((1 << MacroIDBits)-1);
100  }
101
102  unsigned getMacroPhysOffs() const {
103    assert(isMacroID() && "Is not a macro id!");
104    return (ID >> MacroLogOffBits) & ((1 << MacroPhysOffsBits)-1);
105  }
106
107  unsigned getMacroLogOffs() const {
108    assert(isMacroID() && "Is not a macro id!");
109    return ID & ((1 << MacroPhysOffsBits)-1);
110  }
111
112  /// getFileLocWithOffset - Return a source location with the specified offset
113  /// from this file SourceLocation.
114  SourceLocation getFileLocWithOffset(unsigned Offset) const {
115    return getFileLoc(getFileID(), getRawFilePos()+Offset);
116  }
117
118  /// getRawEncoding - When a SourceLocation itself cannot be used, this returns
119  /// an (opaque) 32-bit integer encoding for it.  This should only be passed
120  /// to SourceLocation::getFromRawEncoding, it should not be inspected
121  /// directly.
122  unsigned getRawEncoding() const { return ID; }
123
124  /// getFromRawEncoding - Turn a raw encoding of a SourceLocation object into
125  /// a real SourceLocation.
126  static SourceLocation getFromRawEncoding(unsigned Encoding) {
127    SourceLocation X;
128    X.ID = Encoding;
129    return X;
130  }
131};
132
133inline bool operator==(const SourceLocation &LHS, const SourceLocation &RHS) {
134  return LHS.getRawEncoding() == RHS.getRawEncoding();
135}
136
137inline bool operator!=(const SourceLocation &LHS, const SourceLocation &RHS) {
138  return !(LHS == RHS);
139}
140
141/// SourceRange - a trival tuple used to represent a source range.
142class SourceRange {
143  SourceLocation B;
144  SourceLocation E;
145public:
146  SourceRange(): B(SourceLocation()), E(SourceLocation()) {}
147  SourceRange(SourceLocation loc) : B(loc), E(loc) {}
148  SourceRange(SourceLocation begin, SourceLocation end) : B(begin), E(end) {}
149
150  SourceLocation Begin() const { return B; }
151  SourceLocation End() const { return E; }
152
153  bool isValid() const { return B.isValid() && E.isValid(); }
154};
155
156}  // end namespace clang
157
158#endif
159