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//===--- 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/Target/TargetRegistry.h"
#include "llvm/System/Host.h"
#include <cassert>
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 &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::getHostTriple(), Error);
if (TheTarget && !TheTarget->hasJIT()) {
Error = "No JIT compatible target available for this host";
return 0;
}
return TheTarget;
}