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Make this function work with non-abstract types.

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@17905 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2004-11-16 20:30:53 +00:00
parent a63acbfeab
commit 8511c351dc
1 changed files with 35 additions and 14 deletions
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49
lib/VMCore/Type.cpp
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@ -585,40 +585,61 @@ static bool TypesEqual(const Type *Ty, const Type *Ty2) {
return TypesEqual(Ty, Ty2, EqTypes);
}
// TypeHasCycleThrough - Return true there is a path from CurTy to TargetTy in
// the type graph. We know that Ty is an abstract type, so if we ever reach a
// non-abstract type, we know that we don't need to search the subgraph.
static bool TypeHasCycleThrough(const Type *TargetTy, const Type *CurTy,
// AbstractTypeHasCycleThrough - Return true there is a path from CurTy to
// TargetTy in the type graph. We know that Ty is an abstract type, so if we
// ever reach a non-abstract type, we know that we don't need to search the
// subgraph.
static bool AbstractTypeHasCycleThrough(const Type *TargetTy, const Type *CurTy,
std::set<const Type*> &VisitedTypes) {
if (TargetTy == CurTy) return true;
if (!CurTy->isAbstract()) return false;
std::set<const Type*>::iterator VTI = VisitedTypes.lower_bound(CurTy);
if (VTI != VisitedTypes.end() && *VTI == CurTy)
return false;
VisitedTypes.insert(VTI, CurTy);
if (!VisitedTypes.insert(CurTy).second)
return false; // Already been here.
for (Type::subtype_iterator I = CurTy->subtype_begin(),
E = CurTy->subtype_end(); I != E; ++I)
if (TypeHasCycleThrough(TargetTy, *I, VisitedTypes))
if (AbstractTypeHasCycleThrough(TargetTy, *I, VisitedTypes))
return true;
return false;
}
static bool ConcreteTypeHasCycleThrough(const Type *TargetTy, const Type *CurTy,
std::set<const Type*> &VisitedTypes) {
if (TargetTy == CurTy) return true;
if (!VisitedTypes.insert(CurTy).second)
return false; // Already been here.
for (Type::subtype_iterator I = CurTy->subtype_begin(),
E = CurTy->subtype_end(); I != E; ++I)
if (ConcreteTypeHasCycleThrough(TargetTy, *I, VisitedTypes))
return true;
return false;
}
/// TypeHasCycleThroughItself - Return true if the specified type has a cycle
/// back to itself.
static bool TypeHasCycleThroughItself(const Type *Ty) {
assert(Ty->isAbstract() && "This code assumes that Ty was abstract!");
std::set<const Type*> VisitedTypes;
for (Type::subtype_iterator I = Ty->subtype_begin(), E = Ty->subtype_end();
I != E; ++I)
if (TypeHasCycleThrough(Ty, *I, VisitedTypes))
return true;
if (Ty->isAbstract()) { // Optimized case for abstract types.
for (Type::subtype_iterator I = Ty->subtype_begin(), E = Ty->subtype_end();
I != E; ++I)
if (AbstractTypeHasCycleThrough(Ty, *I, VisitedTypes))
return true;
} else {
for (Type::subtype_iterator I = Ty->subtype_begin(), E = Ty->subtype_end();
I != E; ++I)
if (ConcreteTypeHasCycleThrough(Ty, *I, VisitedTypes))
return true;
}
return false;
}
//===----------------------------------------------------------------------===//
// Derived Type Factory Functions
//===----------------------------------------------------------------------===//