1//===- Multilib.cpp - Multilib 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#include "clang/Driver/Multilib.h"
10#include "clang/Basic/LLVM.h"
11#include "clang/Basic/Version.h"
12#include "llvm/ADT/DenseSet.h"
13#include "llvm/ADT/SmallString.h"
14#include "llvm/ADT/StringRef.h"
15#include "llvm/Support/Compiler.h"
16#include "llvm/Support/Error.h"
17#include "llvm/Support/ErrorHandling.h"
18#include "llvm/Support/Path.h"
19#include "llvm/Support/Regex.h"
20#include "llvm/Support/VersionTuple.h"
21#include "llvm/Support/YAMLParser.h"
22#include "llvm/Support/YAMLTraits.h"
23#include "llvm/Support/raw_ostream.h"
24#include <algorithm>
25#include <cassert>
26#include <string>
27
28using namespace clang;
29using namespace driver;
30using namespace llvm::sys;
31
32Multilib::Multilib(StringRef GCCSuffix, StringRef OSSuffix,
33                   StringRef IncludeSuffix, const flags_list &Flags,
34                   StringRef ExclusiveGroup)
35    : GCCSuffix(GCCSuffix), OSSuffix(OSSuffix), IncludeSuffix(IncludeSuffix),
36      Flags(Flags), ExclusiveGroup(ExclusiveGroup) {
37  assert(GCCSuffix.empty() ||
38         (StringRef(GCCSuffix).front() == '/' && GCCSuffix.size() > 1));
39  assert(OSSuffix.empty() ||
40         (StringRef(OSSuffix).front() == '/' && OSSuffix.size() > 1));
41  assert(IncludeSuffix.empty() ||
42         (StringRef(IncludeSuffix).front() == '/' && IncludeSuffix.size() > 1));
43}
44
45LLVM_DUMP_METHOD void Multilib::dump() const {
46  print(llvm::errs());
47}
48
49void Multilib::print(raw_ostream &OS) const {
50  if (GCCSuffix.empty())
51    OS << ".";
52  else {
53    OS << StringRef(GCCSuffix).drop_front();
54  }
55  OS << ";";
56  for (StringRef Flag : Flags) {
57    if (Flag.front() == '-')
58      OS << "@" << Flag.substr(1);
59  }
60}
61
62bool Multilib::operator==(const Multilib &Other) const {
63  // Check whether the flags sets match
64  // allowing for the match to be order invariant
65  llvm::StringSet<> MyFlags;
66  for (const auto &Flag : Flags)
67    MyFlags.insert(Flag);
68
69  for (const auto &Flag : Other.Flags)
70    if (!MyFlags.contains(Flag))
71      return false;
72
73  if (osSuffix() != Other.osSuffix())
74    return false;
75
76  if (gccSuffix() != Other.gccSuffix())
77    return false;
78
79  if (includeSuffix() != Other.includeSuffix())
80    return false;
81
82  return true;
83}
84
85raw_ostream &clang::driver::operator<<(raw_ostream &OS, const Multilib &M) {
86  M.print(OS);
87  return OS;
88}
89
90MultilibSet &MultilibSet::FilterOut(FilterCallback F) {
91  llvm::erase_if(Multilibs, F);
92  return *this;
93}
94
95void MultilibSet::push_back(const Multilib &M) { Multilibs.push_back(M); }
96
97bool MultilibSet::select(const Multilib::flags_list &Flags,
98                         llvm::SmallVectorImpl<Multilib> &Selected) const {
99  llvm::StringSet<> FlagSet(expandFlags(Flags));
100  Selected.clear();
101
102  // Decide which multilibs we're going to select at all.
103  llvm::DenseSet<StringRef> ExclusiveGroupsSelected;
104  for (const Multilib &M : llvm::reverse(Multilibs)) {
105    // If this multilib doesn't match all our flags, don't select it.
106    if (!llvm::all_of(M.flags(), [&FlagSet](const std::string &F) {
107          return FlagSet.contains(F);
108        }))
109      continue;
110
111    const std::string &group = M.exclusiveGroup();
112    if (!group.empty()) {
113      // If this multilib has the same ExclusiveGroup as one we've already
114      // selected, skip it. We're iterating in reverse order, so the group
115      // member we've selected already is preferred.
116      //
117      // Otherwise, add the group name to the set of groups we've already
118      // selected a member of.
119      auto [It, Inserted] = ExclusiveGroupsSelected.insert(group);
120      if (!Inserted)
121        continue;
122    }
123
124    // Select this multilib.
125    Selected.push_back(M);
126  }
127
128  // We iterated in reverse order, so now put Selected back the right way
129  // round.
130  std::reverse(Selected.begin(), Selected.end());
131
132  return !Selected.empty();
133}
134
135llvm::StringSet<>
136MultilibSet::expandFlags(const Multilib::flags_list &InFlags) const {
137  llvm::StringSet<> Result;
138  for (const auto &F : InFlags)
139    Result.insert(F);
140  for (const FlagMatcher &M : FlagMatchers) {
141    std::string RegexString(M.Match);
142
143    // Make the regular expression match the whole string.
144    if (!StringRef(M.Match).starts_with("^"))
145      RegexString.insert(RegexString.begin(), '^');
146    if (!StringRef(M.Match).ends_with("$"))
147      RegexString.push_back('$');
148
149    const llvm::Regex Regex(RegexString);
150    assert(Regex.isValid());
151    if (llvm::any_of(InFlags,
152                     [&Regex](StringRef F) { return Regex.match(F); })) {
153      Result.insert(M.Flags.begin(), M.Flags.end());
154    }
155  }
156  return Result;
157}
158
159namespace {
160
161// When updating this also update MULTILIB_VERSION in MultilibTest.cpp
162static const VersionTuple MultilibVersionCurrent(1, 0);
163
164struct MultilibSerialization {
165  std::string Dir;
166  std::vector<std::string> Flags;
167  std::string Group;
168};
169
170enum class MultilibGroupType {
171  /*
172   * The only group type currently supported is 'Exclusive', which indicates a
173   * group of multilibs of which at most one may be selected.
174   */
175  Exclusive,
176
177  /*
178   * Future possibility: a second group type indicating a set of library
179   * directories that are mutually _dependent_ rather than mutually exclusive:
180   * if you include one you must include them all.
181   *
182   * It might also be useful to allow groups to be members of other groups, so
183   * that a mutually exclusive group could contain a mutually dependent set of
184   * library directories, or vice versa.
185   *
186   * These additional features would need changes in the implementation, but
187   * the YAML schema is set up so they can be added without requiring changes
188   * in existing users' multilib.yaml files.
189   */
190};
191
192struct MultilibGroupSerialization {
193  std::string Name;
194  MultilibGroupType Type;
195};
196
197struct MultilibSetSerialization {
198  llvm::VersionTuple MultilibVersion;
199  std::vector<MultilibGroupSerialization> Groups;
200  std::vector<MultilibSerialization> Multilibs;
201  std::vector<MultilibSet::FlagMatcher> FlagMatchers;
202};
203
204} // end anonymous namespace
205
206template <> struct llvm::yaml::MappingTraits<MultilibSerialization> {
207  static void mapping(llvm::yaml::IO &io, MultilibSerialization &V) {
208    io.mapRequired("Dir", V.Dir);
209    io.mapRequired("Flags", V.Flags);
210    io.mapOptional("Group", V.Group);
211  }
212  static std::string validate(IO &io, MultilibSerialization &V) {
213    if (StringRef(V.Dir).starts_with("/"))
214      return "paths must be relative but \"" + V.Dir + "\" starts with \"/\"";
215    return std::string{};
216  }
217};
218
219template <> struct llvm::yaml::ScalarEnumerationTraits<MultilibGroupType> {
220  static void enumeration(IO &io, MultilibGroupType &Val) {
221    io.enumCase(Val, "Exclusive", MultilibGroupType::Exclusive);
222  }
223};
224
225template <> struct llvm::yaml::MappingTraits<MultilibGroupSerialization> {
226  static void mapping(llvm::yaml::IO &io, MultilibGroupSerialization &V) {
227    io.mapRequired("Name", V.Name);
228    io.mapRequired("Type", V.Type);
229  }
230};
231
232template <> struct llvm::yaml::MappingTraits<MultilibSet::FlagMatcher> {
233  static void mapping(llvm::yaml::IO &io, MultilibSet::FlagMatcher &M) {
234    io.mapRequired("Match", M.Match);
235    io.mapRequired("Flags", M.Flags);
236  }
237  static std::string validate(IO &io, MultilibSet::FlagMatcher &M) {
238    llvm::Regex Regex(M.Match);
239    std::string RegexError;
240    if (!Regex.isValid(RegexError))
241      return RegexError;
242    if (M.Flags.empty())
243      return "value required for 'Flags'";
244    return std::string{};
245  }
246};
247
248template <> struct llvm::yaml::MappingTraits<MultilibSetSerialization> {
249  static void mapping(llvm::yaml::IO &io, MultilibSetSerialization &M) {
250    io.mapRequired("MultilibVersion", M.MultilibVersion);
251    io.mapRequired("Variants", M.Multilibs);
252    io.mapOptional("Groups", M.Groups);
253    io.mapOptional("Mappings", M.FlagMatchers);
254  }
255  static std::string validate(IO &io, MultilibSetSerialization &M) {
256    if (M.MultilibVersion.empty())
257      return "missing required key 'MultilibVersion'";
258    if (M.MultilibVersion.getMajor() != MultilibVersionCurrent.getMajor())
259      return "multilib version " + M.MultilibVersion.getAsString() +
260             " is unsupported";
261    if (M.MultilibVersion.getMinor() > MultilibVersionCurrent.getMinor())
262      return "multilib version " + M.MultilibVersion.getAsString() +
263             " is unsupported";
264    for (const MultilibSerialization &Lib : M.Multilibs) {
265      if (!Lib.Group.empty()) {
266        bool Found = false;
267        for (const MultilibGroupSerialization &Group : M.Groups)
268          if (Group.Name == Lib.Group) {
269            Found = true;
270            break;
271          }
272        if (!Found)
273          return "multilib \"" + Lib.Dir +
274                 "\" specifies undefined group name \"" + Lib.Group + "\"";
275      }
276    }
277    return std::string{};
278  }
279};
280
281LLVM_YAML_IS_SEQUENCE_VECTOR(MultilibSerialization)
282LLVM_YAML_IS_SEQUENCE_VECTOR(MultilibGroupSerialization)
283LLVM_YAML_IS_SEQUENCE_VECTOR(MultilibSet::FlagMatcher)
284
285llvm::ErrorOr<MultilibSet>
286MultilibSet::parseYaml(llvm::MemoryBufferRef Input,
287                       llvm::SourceMgr::DiagHandlerTy DiagHandler,
288                       void *DiagHandlerCtxt) {
289  MultilibSetSerialization MS;
290  llvm::yaml::Input YamlInput(Input, nullptr, DiagHandler, DiagHandlerCtxt);
291  YamlInput >> MS;
292  if (YamlInput.error())
293    return YamlInput.error();
294
295  multilib_list Multilibs;
296  Multilibs.reserve(MS.Multilibs.size());
297  for (const auto &M : MS.Multilibs) {
298    std::string Dir;
299    if (M.Dir != ".")
300      Dir = "/" + M.Dir;
301    // We transfer M.Group straight into the ExclusiveGroup parameter for the
302    // Multilib constructor. If we later support more than one type of group,
303    // we'll have to look up the group name in MS.Groups, check its type, and
304    // decide what to do here.
305    Multilibs.emplace_back(Dir, Dir, Dir, M.Flags, M.Group);
306  }
307
308  return MultilibSet(std::move(Multilibs), std::move(MS.FlagMatchers));
309}
310
311LLVM_DUMP_METHOD void MultilibSet::dump() const {
312  print(llvm::errs());
313}
314
315void MultilibSet::print(raw_ostream &OS) const {
316  for (const auto &M : *this)
317    OS << M << "\n";
318}
319
320raw_ostream &clang::driver::operator<<(raw_ostream &OS, const MultilibSet &MS) {
321  MS.print(OS);
322  return OS;
323}
324