1 //===--- TargetRegistry.cpp - Target registration -------------------------===//
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 "llvm/Support/TargetRegistry.h"
10 #include "llvm/ADT/STLExtras.h"
11 #include "llvm/ADT/StringRef.h"
12 #include "llvm/Support/raw_ostream.h"
13 #include <cassert>
14 #include <vector>
15 using namespace llvm;
16
17 // Clients are responsible for avoid race conditions in registration.
18 static Target *FirstTarget = nullptr;
19
targets()20 iterator_range<TargetRegistry::iterator> TargetRegistry::targets() {
21 return make_range(iterator(FirstTarget), iterator());
22 }
23
lookupTarget(const std::string & ArchName,Triple & TheTriple,std::string & Error)24 const Target *TargetRegistry::lookupTarget(const std::string &ArchName,
25 Triple &TheTriple,
26 std::string &Error) {
27 // Allocate target machine. First, check whether the user has explicitly
28 // specified an architecture to compile for. If so we have to look it up by
29 // name, because it might be a backend that has no mapping to a target triple.
30 const Target *TheTarget = nullptr;
31 if (!ArchName.empty()) {
32 auto I = find_if(targets(),
33 [&](const Target &T) { return ArchName == T.getName(); });
34
35 if (I == targets().end()) {
36 Error = "error: invalid target '" + ArchName + "'.\n";
37 return nullptr;
38 }
39
40 TheTarget = &*I;
41
42 // Adjust the triple to match (if known), otherwise stick with the
43 // given triple.
44 Triple::ArchType Type = Triple::getArchTypeForLLVMName(ArchName);
45 if (Type != Triple::UnknownArch)
46 TheTriple.setArch(Type);
47 } else {
48 // Get the target specific parser.
49 std::string TempError;
50 TheTarget = TargetRegistry::lookupTarget(TheTriple.getTriple(), TempError);
51 if (!TheTarget) {
52 Error = ": error: unable to get target for '"
53 + TheTriple.getTriple()
54 + "', see --version and --triple.\n";
55 return nullptr;
56 }
57 }
58
59 return TheTarget;
60 }
61
lookupTarget(const std::string & TT,std::string & Error)62 const Target *TargetRegistry::lookupTarget(const std::string &TT,
63 std::string &Error) {
64 // Provide special warning when no targets are initialized.
65 if (targets().begin() == targets().end()) {
66 Error = "Unable to find target for this triple (no targets are registered)";
67 return nullptr;
68 }
69 Triple::ArchType Arch = Triple(TT).getArch();
70 auto ArchMatch = [&](const Target &T) { return T.ArchMatchFn(Arch); };
71 auto I = find_if(targets(), ArchMatch);
72
73 if (I == targets().end()) {
74 Error = "No available targets are compatible with triple \"" + TT + "\"";
75 return nullptr;
76 }
77
78 auto J = std::find_if(std::next(I), targets().end(), ArchMatch);
79 if (J != targets().end()) {
80 Error = std::string("Cannot choose between targets \"") + I->Name +
81 "\" and \"" + J->Name + "\"";
82 return nullptr;
83 }
84
85 return &*I;
86 }
87
RegisterTarget(Target & T,const char * Name,const char * ShortDesc,const char * BackendName,Target::ArchMatchFnTy ArchMatchFn,bool HasJIT)88 void TargetRegistry::RegisterTarget(Target &T, const char *Name,
89 const char *ShortDesc,
90 const char *BackendName,
91 Target::ArchMatchFnTy ArchMatchFn,
92 bool HasJIT) {
93 assert(Name && ShortDesc && ArchMatchFn &&
94 "Missing required target information!");
95
96 // Check if this target has already been initialized, we allow this as a
97 // convenience to some clients.
98 if (T.Name)
99 return;
100
101 // Add to the list of targets.
102 T.Next = FirstTarget;
103 FirstTarget = &T;
104
105 T.Name = Name;
106 T.ShortDesc = ShortDesc;
107 T.BackendName = BackendName;
108 T.ArchMatchFn = ArchMatchFn;
109 T.HasJIT = HasJIT;
110 }
111
TargetArraySortFn(const std::pair<StringRef,const Target * > * LHS,const std::pair<StringRef,const Target * > * RHS)112 static int TargetArraySortFn(const std::pair<StringRef, const Target *> *LHS,
113 const std::pair<StringRef, const Target *> *RHS) {
114 return LHS->first.compare(RHS->first);
115 }
116
printRegisteredTargetsForVersion(raw_ostream & OS)117 void TargetRegistry::printRegisteredTargetsForVersion(raw_ostream &OS) {
118 std::vector<std::pair<StringRef, const Target*> > Targets;
119 size_t Width = 0;
120 for (const auto &T : TargetRegistry::targets()) {
121 Targets.push_back(std::make_pair(T.getName(), &T));
122 Width = std::max(Width, Targets.back().first.size());
123 }
124 array_pod_sort(Targets.begin(), Targets.end(), TargetArraySortFn);
125
126 OS << " Registered Targets:\n";
127 for (unsigned i = 0, e = Targets.size(); i != e; ++i) {
128 OS << " " << Targets[i].first;
129 OS.indent(Width - Targets[i].first.size()) << " - "
130 << Targets[i].second->getShortDescription() << '\n';
131 }
132 if (Targets.empty())
133 OS << " (none)\n";
134 }
135