1 //===--- ItaniumManglingCanonicalizer.h -------------------------*- C++ -*-===//
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 defines a class for computing equivalence classes of mangled names
11 // given a set of equivalences between name fragments.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_SUPPORT_ITANIUMMANGLINGCANONICALIZER_H
16 #define LLVM_SUPPORT_ITANIUMMANGLINGCANONICALIZER_H
17 
18 #include "llvm/ADT/StringRef.h"
19 
20 #include <cstddef>
21 
22 namespace llvm {
23 /// Canonicalizer for mangled names.
24 ///
25 /// This class allows specifying a list of "equivalent" manglings. For example,
26 /// you can specify that Ss is equivalent to
27 ///   NSt3__112basic_stringIcNS_11char_traitsIcEENS_9allocatorIcEEEE
28 /// and then manglings that refer to libstdc++'s 'std::string' will be
29 /// considered equivalent to manglings that are the same except that they refer
30 /// to libc++'s 'std::string'.
31 ///
32 /// This can be used when data (eg, profiling data) is available for a version
33 /// of a program built in a different configuration, with correspondingly
34 /// different manglings.
35 class ItaniumManglingCanonicalizer {
36 public:
37   ItaniumManglingCanonicalizer();
38   ItaniumManglingCanonicalizer(const ItaniumManglingCanonicalizer &) = delete;
39   void operator=(const ItaniumManglingCanonicalizer &) = delete;
40   ~ItaniumManglingCanonicalizer();
41 
42   enum class EquivalenceError {
43     Success,
44 
45     /// Both the equivalent manglings have already been used as components of
46     /// some other mangling we've looked at. It's too late to add this
47     /// equivalence.
48     ManglingAlreadyUsed,
49 
50     /// The first equivalent mangling is invalid.
51     InvalidFirstMangling,
52 
53     /// The second equivalent mangling is invalid.
54     InvalidSecondMangling,
55   };
56 
57   enum class FragmentKind {
58     /// The mangling fragment is a <name> (or a predefined <substitution>).
59     Name,
60     /// The mangling fragment is a <type>.
61     Type,
62     /// The mangling fragment is an <encoding>.
63     Encoding,
64   };
65 
66   /// Add an equivalence between \p First and \p Second. Both manglings must
67   /// live at least as long as the canonicalizer.
68   EquivalenceError addEquivalence(FragmentKind Kind, StringRef First,
69                                   StringRef Second);
70 
71   using Key = uintptr_t;
72 
73   /// Form a canonical key for the specified mangling. They key will be the
74   /// same for all equivalent manglings, and different for any two
75   /// non-equivalent manglings, but is otherwise unspecified.
76   ///
77   /// Returns Key() if (and only if) the mangling is not a valid Itanium C++
78   /// ABI mangling.
79   ///
80   /// The string denoted by Mangling must live as long as the canonicalizer.
81   Key canonicalize(StringRef Mangling);
82 
83   /// Find a canonical key for the specified mangling, if one has already been
84   /// formed. Otherwise returns Key().
85   Key lookup(StringRef Mangling);
86 
87 private:
88   struct Impl;
89   Impl *P;
90 };
91 } // namespace llvm
92 
93 #endif // LLVM_SUPPORT_ITANIUMMANGLINGCANONICALIZER_H
94