averello/swift-mirror
1
0
Fork 0
mirror of https://github.com/apple/swift.git synced 2025-12-21 12:14:44 +01:00
Code Issues Packages Projects Releases Wiki Activity

Treat deducible generic parameter types as unresolved types, because

Browse Source 
they need to be substituted away for any type containing them to be
useful. A nice side-effect of this is that we'll actually properly
walk into the source type when a generic function returns, e.g., a
tuple type that involves type parameters not resolved by the input
arguments.


Swift SVN r2302
This commit is contained in:
Doug Gregor
2012-07-03 23:23:25 +00:00
parent 99fac3aaa8
commit ad2fa39eaa
2 changed files with 14 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
include/swift/AST/Types.h
View File

@@ -1235,7 +1235,7 @@ class DeducibleGenericParamType : public SubstitutableType {
DeducibleGenericParamType(ASTContext &Ctx, Identifier Name, unsigned Index,
ArrayRef<ProtocolDecl *> ConformsTo)
: SubstitutableType(TypeKind::DeducibleGenericParam, &Ctx,
/*Unresolved=*/false, ConformsTo),
/*Unresolved=*/true, ConformsTo),
Name(Name), Index(Index) { }
public:

13
lib/Sema/TypeCheckCoercion.cpp
View File

@@ -229,6 +229,17 @@ class SemaCoerce : public ExprVisitor<SemaCoerce, CoercedResult> {
/// \brief Try to perform a user-defined conversion.
CoercedResult tryUserConversion(Expr *E);
/// \brief Determine whether the given types are the same, deducing
/// any deducible arguments along the way.
static bool sameType(Type T1, Type T2, CoercionContext &CC) {
// FIXME: This is really an approximation of the behavior we want, which
// would be to check for identical type structure while potentially
// deducing at each step.
bool Trivial;
return CC.TC.isSubtypeOf(T1, T2, Trivial, &CC) && Trivial &&
CC.TC.isSubtypeOf(T2, T1, Trivial, &CC) && Trivial;
}
public:
CoercedResult visitErrorExpr(ErrorExpr *E) {
return unchanged(E);
@@ -1488,7 +1499,7 @@ SemaCoerce::convertTupleToTupleType(Expr *E, unsigned NumExprElements,
// Because we have coerced something in the source tuple, we need to
// rebuild the type of that tuple.
RebuildSourceType = true;
} else if (ETy && !ElementTy->isEqual(DestEltTy)) {
} else if (ETy && !sameType(ElementTy, DestEltTy, CC)) {
// FIXME: Allow conversions when we don't have a tuple expression?
if (Flags & CF_Apply)
TC.diagnose(E->getLoc(), diag::tuple_element_type_mismatch, SrcField,