Builtins.cpp revision 1.1.1.1 
1//===--- Builtins.cpp - Builtin function implementation -------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9//  This file implements various things for builtin functions.
10//
11//===----------------------------------------------------------------------===//
12
13#include "clang/Basic/Builtins.h"
14#include "clang/Basic/IdentifierTable.h"
15#include "clang/Basic/LangOptions.h"
16#include "clang/Basic/TargetInfo.h"
17#include "llvm/ADT/StringRef.h"
18using namespace clang;
19
20static const Builtin::Info BuiltinInfo[] = {
21  { "not a builtin function", nullptr, nullptr, nullptr, ALL_LANGUAGES,nullptr},
22#define BUILTIN(ID, TYPE, ATTRS)                                               \
23  { #ID, TYPE, ATTRS, nullptr, ALL_LANGUAGES, nullptr },
24#define LANGBUILTIN(ID, TYPE, ATTRS, LANGS)                                    \
25  { #ID, TYPE, ATTRS, nullptr, LANGS, nullptr },
26#define LIBBUILTIN(ID, TYPE, ATTRS, HEADER, LANGS)                             \
27  { #ID, TYPE, ATTRS, HEADER, LANGS, nullptr },
28#include "clang/Basic/Builtins.def"
29};
30
31const Builtin::Info &Builtin::Context::getRecord(unsigned ID) const {
32  if (ID < Builtin::FirstTSBuiltin)
33    return BuiltinInfo[ID];
34  assert(((ID - Builtin::FirstTSBuiltin) <
35          (TSRecords.size() + AuxTSRecords.size())) &&
36         "Invalid builtin ID!");
37  if (isAuxBuiltinID(ID))
38    return AuxTSRecords[getAuxBuiltinID(ID) - Builtin::FirstTSBuiltin];
39  return TSRecords[ID - Builtin::FirstTSBuiltin];
40}
41
42void Builtin::Context::InitializeTarget(const TargetInfo &Target,
43                                        const TargetInfo *AuxTarget) {
44  assert(TSRecords.empty() && "Already initialized target?");
45  TSRecords = Target.getTargetBuiltins();
46  if (AuxTarget)
47    AuxTSRecords = AuxTarget->getTargetBuiltins();
48}
49
50bool Builtin::Context::isBuiltinFunc(const char *Name) {
51  StringRef FuncName(Name);
52  for (unsigned i = Builtin::NotBuiltin + 1; i != Builtin::FirstTSBuiltin; ++i)
53    if (FuncName.equals(BuiltinInfo[i].Name))
54      return strchr(BuiltinInfo[i].Attributes, 'f') != nullptr;
55
56  return false;
57}
58
59bool Builtin::Context::builtinIsSupported(const Builtin::Info &BuiltinInfo,
60                                          const LangOptions &LangOpts) {
61  bool BuiltinsUnsupported =
62      (LangOpts.NoBuiltin || LangOpts.isNoBuiltinFunc(BuiltinInfo.Name)) &&
63      strchr(BuiltinInfo.Attributes, 'f');
64  bool MathBuiltinsUnsupported =
65    LangOpts.NoMathBuiltin && BuiltinInfo.HeaderName &&
66    llvm::StringRef(BuiltinInfo.HeaderName).equals("math.h");
67  bool GnuModeUnsupported = !LangOpts.GNUMode && (BuiltinInfo.Langs & GNU_LANG);
68  bool MSModeUnsupported =
69      !LangOpts.MicrosoftExt && (BuiltinInfo.Langs & MS_LANG);
70  bool ObjCUnsupported = !LangOpts.ObjC && BuiltinInfo.Langs == OBJC_LANG;
71  bool OclC1Unsupported = (LangOpts.OpenCLVersion / 100) != 1 &&
72                          (BuiltinInfo.Langs & ALL_OCLC_LANGUAGES ) ==  OCLC1X_LANG;
73  bool OclC2Unsupported =
74      (LangOpts.OpenCLVersion != 200 && !LangOpts.OpenCLCPlusPlus) &&
75      (BuiltinInfo.Langs & ALL_OCLC_LANGUAGES) == OCLC20_LANG;
76  bool OclCUnsupported = !LangOpts.OpenCL &&
77                         (BuiltinInfo.Langs & ALL_OCLC_LANGUAGES);
78  bool OpenMPUnsupported = !LangOpts.OpenMP && BuiltinInfo.Langs == OMP_LANG;
79  bool CPlusPlusUnsupported =
80      !LangOpts.CPlusPlus && BuiltinInfo.Langs == CXX_LANG;
81  return !BuiltinsUnsupported && !MathBuiltinsUnsupported && !OclCUnsupported &&
82         !OclC1Unsupported && !OclC2Unsupported && !OpenMPUnsupported &&
83         !GnuModeUnsupported && !MSModeUnsupported && !ObjCUnsupported &&
84         !CPlusPlusUnsupported;
85}
86
87/// initializeBuiltins - Mark the identifiers for all the builtins with their
88/// appropriate builtin ID # and mark any non-portable builtin identifiers as
89/// such.
90void Builtin::Context::initializeBuiltins(IdentifierTable &Table,
91                                          const LangOptions& LangOpts) {
92  // Step #1: mark all target-independent builtins with their ID's.
93  for (unsigned i = Builtin::NotBuiltin+1; i != Builtin::FirstTSBuiltin; ++i)
94    if (builtinIsSupported(BuiltinInfo[i], LangOpts)) {
95      Table.get(BuiltinInfo[i].Name).setBuiltinID(i);
96    }
97
98  // Step #2: Register target-specific builtins.
99  for (unsigned i = 0, e = TSRecords.size(); i != e; ++i)
100    if (builtinIsSupported(TSRecords[i], LangOpts))
101      Table.get(TSRecords[i].Name).setBuiltinID(i + Builtin::FirstTSBuiltin);
102
103  // Step #3: Register target-specific builtins for AuxTarget.
104  for (unsigned i = 0, e = AuxTSRecords.size(); i != e; ++i)
105    Table.get(AuxTSRecords[i].Name)
106        .setBuiltinID(i + Builtin::FirstTSBuiltin + TSRecords.size());
107}
108
109void Builtin::Context::forgetBuiltin(unsigned ID, IdentifierTable &Table) {
110  Table.get(getRecord(ID).Name).setBuiltinID(0);
111}
112
113unsigned Builtin::Context::getRequiredVectorWidth(unsigned ID) const {
114  const char *WidthPos = ::strchr(getRecord(ID).Attributes, 'V');
115  if (!WidthPos)
116    return 0;
117
118  ++WidthPos;
119  assert(*WidthPos == ':' &&
120         "Vector width specifier must be followed by a ':'");
121  ++WidthPos;
122
123  char *EndPos;
124  unsigned Width = ::strtol(WidthPos, &EndPos, 10);
125  assert(*EndPos == ':' && "Vector width specific must end with a ':'");
126  return Width;
127}
128
129bool Builtin::Context::isLike(unsigned ID, unsigned &FormatIdx,
130                              bool &HasVAListArg, const char *Fmt) const {
131  assert(Fmt && "Not passed a format string");
132  assert(::strlen(Fmt) == 2 &&
133         "Format string needs to be two characters long");
134  assert(::toupper(Fmt[0]) == Fmt[1] &&
135         "Format string is not in the form \"xX\"");
136
137  const char *Like = ::strpbrk(getRecord(ID).Attributes, Fmt);
138  if (!Like)
139    return false;
140
141  HasVAListArg = (*Like == Fmt[1]);
142
143  ++Like;
144  assert(*Like == ':' && "Format specifier must be followed by a ':'");
145  ++Like;
146
147  assert(::strchr(Like, ':') && "Format specifier must end with a ':'");
148  FormatIdx = ::strtol(Like, nullptr, 10);
149  return true;
150}
151
152bool Builtin::Context::isPrintfLike(unsigned ID, unsigned &FormatIdx,
153                                    bool &HasVAListArg) {
154  return isLike(ID, FormatIdx, HasVAListArg, "pP");
155}
156
157bool Builtin::Context::isScanfLike(unsigned ID, unsigned &FormatIdx,
158                                   bool &HasVAListArg) {
159  return isLike(ID, FormatIdx, HasVAListArg, "sS");
160}
161
162bool Builtin::Context::performsCallback(unsigned ID,
163                                        SmallVectorImpl<int> &Encoding) const {
164  const char *CalleePos = ::strchr(getRecord(ID).Attributes, 'C');
165  if (!CalleePos)
166    return false;
167
168  ++CalleePos;
169  assert(*CalleePos == '<' &&
170         "Callback callee specifier must be followed by a '<'");
171  ++CalleePos;
172
173  char *EndPos;
174  int CalleeIdx = ::strtol(CalleePos, &EndPos, 10);
175  assert(CalleeIdx >= 0 && "Callee index is supposed to be positive!");
176  Encoding.push_back(CalleeIdx);
177
178  while (*EndPos == ',') {
179    const char *PayloadPos = EndPos + 1;
180
181    int PayloadIdx = ::strtol(PayloadPos, &EndPos, 10);
182    Encoding.push_back(PayloadIdx);
183  }
184
185  assert(*EndPos == '>' && "Callback callee specifier must end with a '>'");
186  return true;
187}
188
189bool Builtin::Context::canBeRedeclared(unsigned ID) const {
190  return ID == Builtin::NotBuiltin ||
191         ID == Builtin::BI__va_start ||
192         (!hasReferenceArgsOrResult(ID) &&
193          !hasCustomTypechecking(ID));
194}
195