llvm-6502/lib/Support/TargetRegistry.cpp
Benjamin Kramer 0d293e45b6 Provide basic type safety for array_pod_sort comparators.
This makes using array_pod_sort significantly safer. The implementation relies
on function pointer casting but that should be safe as we're dealing with void*
here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191175 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-22 14:09:50 +00:00

164 lines
5.2 KiB
C++

//===--- TargetRegistry.cpp - Target registration -------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/TargetRegistry.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Host.h"
#include "llvm/Support/raw_ostream.h"
#include <cassert>
#include <vector>
using namespace llvm;
// Clients are responsible for avoid race conditions in registration.
static Target *FirstTarget = 0;
TargetRegistry::iterator TargetRegistry::begin() {
return iterator(FirstTarget);
}
const Target *TargetRegistry::lookupTarget(const std::string &ArchName,
Triple &TheTriple,
std::string &Error) {
// Allocate target machine. First, check whether the user has explicitly
// specified an architecture to compile for. If so we have to look it up by
// name, because it might be a backend that has no mapping to a target triple.
const Target *TheTarget = 0;
if (!ArchName.empty()) {
for (TargetRegistry::iterator it = TargetRegistry::begin(),
ie = TargetRegistry::end(); it != ie; ++it) {
if (ArchName == it->getName()) {
TheTarget = &*it;
break;
}
}
if (!TheTarget) {
Error = "error: invalid target '" + ArchName + "'.\n";
return 0;
}
// Adjust the triple to match (if known), otherwise stick with the
// given triple.
Triple::ArchType Type = Triple::getArchTypeForLLVMName(ArchName);
if (Type != Triple::UnknownArch)
TheTriple.setArch(Type);
} else {
// Get the target specific parser.
std::string TempError;
TheTarget = TargetRegistry::lookupTarget(TheTriple.getTriple(), TempError);
if (TheTarget == 0) {
Error = ": error: unable to get target for '"
+ TheTriple.getTriple()
+ "', see --version and --triple.\n";
return 0;
}
}
return TheTarget;
}
const Target *TargetRegistry::lookupTarget(const std::string &TT,
std::string &Error) {
// Provide special warning when no targets are initialized.
if (begin() == end()) {
Error = "Unable to find target for this triple (no targets are registered)";
return 0;
}
const Target *Best = 0, *EquallyBest = 0;
unsigned BestQuality = 0;
for (iterator it = begin(), ie = end(); it != ie; ++it) {
if (unsigned Qual = it->TripleMatchQualityFn(TT)) {
if (!Best || Qual > BestQuality) {
Best = &*it;
EquallyBest = 0;
BestQuality = Qual;
} else if (Qual == BestQuality)
EquallyBest = &*it;
}
}
if (!Best) {
Error = "No available targets are compatible with this triple, "
"see -version for the available targets.";
return 0;
}
// Otherwise, take the best target, but make sure we don't have two equally
// good best targets.
if (EquallyBest) {
Error = std::string("Cannot choose between targets \"") +
Best->Name + "\" and \"" + EquallyBest->Name + "\"";
return 0;
}
return Best;
}
void TargetRegistry::RegisterTarget(Target &T,
const char *Name,
const char *ShortDesc,
Target::TripleMatchQualityFnTy TQualityFn,
bool HasJIT) {
assert(Name && ShortDesc && TQualityFn &&
"Missing required target information!");
// Check if this target has already been initialized, we allow this as a
// convenience to some clients.
if (T.Name)
return;
// Add to the list of targets.
T.Next = FirstTarget;
FirstTarget = &T;
T.Name = Name;
T.ShortDesc = ShortDesc;
T.TripleMatchQualityFn = TQualityFn;
T.HasJIT = HasJIT;
}
const Target *TargetRegistry::getClosestTargetForJIT(std::string &Error) {
const Target *TheTarget = lookupTarget(sys::getDefaultTargetTriple(), Error);
if (TheTarget && !TheTarget->hasJIT()) {
Error = "No JIT compatible target available for this host";
return 0;
}
return TheTarget;
}
static int TargetArraySortFn(const std::pair<StringRef, const Target *> *LHS,
const std::pair<StringRef, const Target *> *RHS) {
return LHS->first.compare(RHS->first);
}
void TargetRegistry::printRegisteredTargetsForVersion() {
std::vector<std::pair<StringRef, const Target*> > Targets;
size_t Width = 0;
for (TargetRegistry::iterator I = TargetRegistry::begin(),
E = TargetRegistry::end();
I != E; ++I) {
Targets.push_back(std::make_pair(I->getName(), &*I));
Width = std::max(Width, Targets.back().first.size());
}
array_pod_sort(Targets.begin(), Targets.end(), TargetArraySortFn);
raw_ostream &OS = outs();
OS << " Registered Targets:\n";
for (unsigned i = 0, e = Targets.size(); i != e; ++i) {
OS << " " << Targets[i].first;
OS.indent(Width - Targets[i].first.size()) << " - "
<< Targets[i].second->getShortDescription() << '\n';
}
if (Targets.empty())
OS << " (none)\n";
}