1 //
2 // Copyright (c) 2017 The ANGLE Project Authors. All rights reserved.
3 // Use of this source code is governed by a BSD-style license that can be
4 // found in the LICENSE file.
5 //
6
7 #include "compiler/translator/HashNames.h"
8
9 #include "compiler/translator/IntermNode.h"
10
11 namespace sh
12 {
13
14 namespace
15 {
16
17 // GLSL ES 3.00.6 section 3.9: the maximum length of an identifier is 1024 characters.
18 static const unsigned int kESSLMaxIdentifierLength = 1024u;
19
20 static const char *kHashedNamePrefix = "webgl_";
21
22 // Can't prefix with just _ because then we might introduce a double underscore, which is not safe
23 // in GLSL (ESSL 3.00.6 section 3.8: All identifiers containing a double underscore are reserved for
24 // use by the underlying implementation). u is short for user-defined.
25 static const char *kUnhashedNamePrefix = "_u";
26 static const unsigned int kUnhashedNamePrefixLength = 2u;
27
HashName(const TString & name,ShHashFunction64 hashFunction)28 TString HashName(const TString &name, ShHashFunction64 hashFunction)
29 {
30 ASSERT(!name.empty());
31 ASSERT(hashFunction);
32 khronos_uint64_t number = (*hashFunction)(name.c_str(), name.length());
33 TStringStream stream;
34 stream << kHashedNamePrefix << std::hex << number;
35 TString hashedName = stream.str();
36 return hashedName;
37 }
38
39 } // anonymous namespace
40
HashName(const TName & name,ShHashFunction64 hashFunction,NameMap * nameMap)41 TString HashName(const TName &name, ShHashFunction64 hashFunction, NameMap *nameMap)
42 {
43 if (name.getString().empty() || name.isInternal())
44 {
45 return name.getString();
46 }
47 if (hashFunction == nullptr)
48 {
49 if (name.getString().length() + kUnhashedNamePrefixLength > kESSLMaxIdentifierLength)
50 {
51 // If the identifier length is already close to the limit, we can't prefix it. This is
52 // not a problem since there are no builtins or ANGLE's internal variables that would
53 // have as long names and could conflict.
54 return name.getString();
55 }
56 return kUnhashedNamePrefix + name.getString();
57 }
58 if (nameMap)
59 {
60 NameMap::const_iterator it = nameMap->find(name.getString().c_str());
61 if (it != nameMap->end())
62 return it->second.c_str();
63 }
64 TString hashedName = HashName(name.getString(), hashFunction);
65 if (nameMap)
66 {
67 (*nameMap)[name.getString().c_str()] = hashedName.c_str();
68 }
69 return hashedName;
70 }
71
72 } // namespace sh
73