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>
15using namespace llvm;
16
17// Clients are responsible for avoid race conditions in registration.
18static Target *FirstTarget = nullptr;
19
20iterator_range<TargetRegistry::iterator> TargetRegistry::targets() {
21 return make_range(x: iterator(FirstTarget), y: iterator());
22}
23
24const 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(Range: targets(),
33 P: [&](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(Str: ArchName);
45 if (Type != Triple::UnknownArch)
46 TheTriple.setArch(Kind: Type);
47 } else {
48 // Get the target specific parser.
49 std::string TempError;
50 TheTarget = TargetRegistry::lookupTarget(Triple: TheTriple.getTriple(), Error&: 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
61const 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(Range: targets(), P: 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(first: std::next(x: I), last: targets().end(), pred: 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
87void 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
111static int TargetArraySortFn(const std::pair<StringRef, const Target *> *LHS,
112 const std::pair<StringRef, const Target *> *RHS) {
113 return LHS->first.compare(RHS: RHS->first);
114}
115
116void 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(x: std::make_pair(x: T.getName(), y: &T));
121 Width = std::max(a: Width, b: Targets.back().first.size());
122 }
123 array_pod_sort(Start: Targets.begin(), End: Targets.end(), Compare: TargetArraySortFn);
124
125 OS << "\n";
126 OS << " Registered Targets:\n";
127 for (const auto &Target : Targets) {
128 OS << " " << Target.first;
129 OS.indent(NumSpaces: Width - Target.first.size())
130 << " - " << Target.second->getShortDescription() << '\n';
131 }
132 if (Targets.empty())
133 OS << " (none)\n";
134}
135

source code of llvm/lib/MC/TargetRegistry.cpp