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/MC/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(StringRef ArchName,Triple & TheTriple,std::string & Error)24 const Target *TargetRegistry::lookupTarget(StringRef 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 = ("invalid target '" + ArchName + "'.\n").str();
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 = "unable to get target for '" + TheTriple.getTriple() +
53 "', see --version and --triple.";
54 return nullptr;
55 }
56 }
57
58 return TheTarget;
59 }
60
lookupTarget(StringRef TT,std::string & Error)61 const Target *TargetRegistry::lookupTarget(StringRef TT, std::string &Error) {
62 // Provide special warning when no targets are initialized.
63 if (targets().begin() == targets().end()) {
64 Error = "Unable to find target for this triple (no targets are registered)";
65 return nullptr;
66 }
67 Triple::ArchType Arch = Triple(TT).getArch();
68 auto ArchMatch = [&](const Target &T) { return T.ArchMatchFn(Arch); };
69 auto I = find_if(targets(), ArchMatch);
70
71 if (I == targets().end()) {
72 Error = ("No available targets are compatible with triple \"" + TT + "\"")
73 .str();
74 return nullptr;
75 }
76
77 auto J = std::find_if(std::next(I), targets().end(), ArchMatch);
78 if (J != targets().end()) {
79 Error = std::string("Cannot choose between targets \"") + I->Name +
80 "\" and \"" + J->Name + "\"";
81 return nullptr;
82 }
83
84 return &*I;
85 }
86
RegisterTarget(Target & T,const char * Name,const char * ShortDesc,const char * BackendName,Target::ArchMatchFnTy ArchMatchFn,bool HasJIT)87 void TargetRegistry::RegisterTarget(Target &T, const char *Name,
88 const char *ShortDesc,
89 const char *BackendName,
90 Target::ArchMatchFnTy ArchMatchFn,
91 bool HasJIT) {
92 assert(Name && ShortDesc && ArchMatchFn &&
93 "Missing required target information!");
94
95 // Check if this target has already been initialized, we allow this as a
96 // convenience to some clients.
97 if (T.Name)
98 return;
99
100 // Add to the list of targets.
101 T.Next = FirstTarget;
102 FirstTarget = &T;
103
104 T.Name = Name;
105 T.ShortDesc = ShortDesc;
106 T.BackendName = BackendName;
107 T.ArchMatchFn = ArchMatchFn;
108 T.HasJIT = HasJIT;
109 }
110
TargetArraySortFn(const std::pair<StringRef,const Target * > * LHS,const std::pair<StringRef,const Target * > * RHS)111 static int TargetArraySortFn(const std::pair<StringRef, const Target *> *LHS,
112 const std::pair<StringRef, const Target *> *RHS) {
113 return LHS->first.compare(RHS->first);
114 }
115
printRegisteredTargetsForVersion(raw_ostream & OS)116 void TargetRegistry::printRegisteredTargetsForVersion(raw_ostream &OS) {
117 std::vector<std::pair<StringRef, const Target*> > Targets;
118 size_t Width = 0;
119 for (const auto &T : TargetRegistry::targets()) {
120 Targets.push_back(std::make_pair(T.getName(), &T));
121 Width = std::max(Width, Targets.back().first.size());
122 }
123 array_pod_sort(Targets.begin(), Targets.end(), TargetArraySortFn);
124
125 OS << "\n";
126 OS << " Registered Targets:\n";
127 for (const auto &Target : Targets) {
128 OS << " " << Target.first;
129 OS.indent(Width - Target.first.size())
130 << " - " << Target.second->getShortDescription() << '\n';
131 }
132 if (Targets.empty())
133 OS << " (none)\n";
134 }
135