diff options
Diffstat (limited to 'chapter14/src/main/java')
| -rw-r--r-- | chapter14/src/main/java/com/seaofnodes/simple/type/TypeStruct.java | 14 |
1 files changed, 6 insertions, 8 deletions
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/type/TypeStruct.java b/chapter14/src/main/java/com/seaofnodes/simple/type/TypeStruct.java index 2599a383..8ad59a39 100644 --- a/chapter14/src/main/java/com/seaofnodes/simple/type/TypeStruct.java +++ b/chapter14/src/main/java/com/seaofnodes/simple/type/TypeStruct.java @@ -8,14 +8,12 @@ import java.util.ArrayList; */ public class TypeStruct extends Type { - // A Struct has a name and a set of fields; the fields themselves have - // names and types. Briefly during parsing its allowed to have a - // forward-ref to a Struct; in this case the _fields array is null. - // Its illegal to attempt to load a field from a forward-ref struct. - // - // During the normal optimization run, struct types "bottom out" at further - // struct references, so we don't have to handle e.g. cyclic types. The - // "bottom out" is again the forward-ref struct. + // Immutable shallow references, resolved by name in Parser.TYPES when needed. + // A name-only struct has _fields == null, even after its definition is known. + // For LLI { LLI? next; int i; }, L0 is name-only and L1.next points to L0; + // TYPES["LLI"] holds L1. We deliberately stop recursive type expansion here, + // keeping interning and lattice operations finite and acyclic. Never patch + // L0 into L1: field access looks up the complete declaration by name instead. public final String _name; public final Field[] _fields; |