RFR: 8194743: Compiler implementation for Statements before super() [v14]

[Maurizio Cimadamore]

On Mon, 25 Sep 2023 14:27:04 GMT, Archie Cobbs <acobbs at openjdk.org> wrote:

>> The kind is used in some other parts of Resolve to determine whether some errors should be skipped in some places, or recovered from. I'd advise against creating a new error kind, which might end up invalidating some existing check which depend on STATICERR. E.g.:
>> 
>> 
>> final boolean shouldStop(Symbol sym, MethodResolutionPhase phase) {
>>             return phase.ordinal() > maxPhase.ordinal() ||
>>                  !sym.kind.isResolutionError() || sym.kind == AMBIGUOUS || sym.kind == STATICERR;
>>         }
>> 
>> 
>> E.g. you don't want overload resolution to try new candidates because you tried to call a method and you don't have a `this` - e.g. the compiler behavior should be similar as to when an instance method is called and no `this` is available (meaning: the found method is correct, and the error should be reported, no attempt should be made at recovery).
>
> OK got it. So what if we did this instead?
> 
> diff --git a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Resolve.java b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Resolve.java
> index 295bb192a42..4c7c177163f 100644
> --- a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Resolve.java
> +++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Resolve.java
> @@ -4576,7 +4587,11 @@ JCDiagnostic inaccessiblePackageReason(Env<AttrContext> env, PackageSymbol sym)
>      class StaticError extends InvalidSymbolError {
>  
>          StaticError(Symbol sym) {
> -            super(STATICERR, sym, "static error");
> +            this(sym, "static error");
> +        }
> +
> +        StaticError(Symbol sym, String debugName) {
> +            super(STATICERR, sym, debugName);
>          }
>  
>          @Override
> @@ -4595,6 +4610,32 @@ JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
>          }
>      }
>  
> +    /**
> +     * Specialization of {@link InvalidSymbolError} for illegal
> +     * early accesses within a constructor prologue.
> +     */
> +    class RefBeforeCtorCalledError extends StaticError {
> +
> +        RefBeforeCtorCalledError(Symbol sym) {
> +            super(sym, "prologue error");
> +        }
> +
> +        @Override
> +        JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
> +                DiagnosticPosition pos,
> +                Symbol location,
> +                Type site,
> +                Name name,
> +                List<Type> argtypes,
> +                List<Type> typeargtypes) {
> +            Symbol errSym = ((sym.kind == TYP && sym.type.hasTag(CLASS))
> +                ? types.erasure(sym.type).tsym
> +                : sym);
> +            return diags.create(dkind, log.currentSource(), pos,
> +                    "cant.ref.before.ctor.called", errSym);
> +        }
> +    }
> +
>      /**
>       * InvalidSymbolError error class indicating that a pair of symbols
>       * (either methods, constructors or operands) are ambiguous
> @@ -4708,7 +4749,7 @@ class BadMethodReferenceError extends StaticError {
>          boolean unboundLookup;
>  
>          public BadMethodReferenceError(Symbol sym, boolean unboundLookup) {
> -            super(sym);
> +            super(sym, "bad method ref error");
>              this.unboundLookup = unboundLookup;
>          }

Yes, I think that is what I was referring to. Thanks for the patience.

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/13656#discussion_r1336028332