Resolve :use/:only refers, refer-aware syntax-quote, alias-aware resolve

Three related namespace-resolution fixes surfaced porting the clojure.tools.logging
library, all general:

- chez-register-spec! treats a :use :only vector like :require :refer, so a
  (:use [ns :only [names]]) clause actually brings those names in. Before, a bare
  reference to an :only'd name resolved to nil.
- syntax-quote (hc-sq-symbol) qualifies a referred name to its SOURCE namespace,
  not the compile namespace — so a macro that syntax-quotes a referred var (e.g.
  clojure.tools.logging/spy reaching clojure.pprint's pprint) expands correctly.
- resolve consults :as aliases and :refers like ns-resolve does; (resolve
  'alias/name) was returning nil because the alias wasn't expanded.

host/chez/host-contract.ss

@@ -225,6 +225,12 @@
           ((hc-special-symbol? nm) form)               ; special form: leave bare
           ((hc-interop-head? nm) form)                 ; interop (.method / Class. / .-field): bare
           ((var-cell-lookup "clojure.core" nm) (jolt-symbol "clojure.core" nm))
+          ;; a name referred into the compile ns (:require :refer / :use :only)
+          ;; qualifies to its SOURCE ns, not the compile ns — so a macro that
+          ;; syntax-quotes a referred var (e.g. clojure.tools.logging/spy using
+          ;; clojure.pprint's pprint) expands to the real var.
+          ((chez-resolve-refer (chez-actx-cns ctx) nm)
+           => (lambda (target) (jolt-symbol target nm)))
           (else (jolt-symbol (chez-actx-cns ctx) nm)))  ; else: qualify to compile ns
         ;; qualified: if the ns part is an :as alias in the compile ns, resolve it
         ;; to the target namespace — Clojure resolves the alias part of a qualified

host/chez/ns.ss

@@ -67,7 +67,9 @@
                 (cond
                   ((string=? (keyword-t-name k) "as")
                    (when (symbol-t? v) (chez-register-alias! cns (symbol-t-name v) target)))
-                  ((string=? (keyword-t-name k) "refer")
+                  ;; :refer (require) and :only (use) both bring unqualified names
+                  ;; into cns resolving to target/name.
+                  ((or (string=? (keyword-t-name k) "refer") (string=? (keyword-t-name k) "only"))
                    (cond
                      ;; :refer :all — bring in every public var (require :refer :all)
                      ((and (keyword? v) (string=? (keyword-t-name v) "all"))
@@ -196,11 +198,16 @@
 ;; resolve: an unqualified symbol resolves in the current ns then clojure.core; a
 ;; qualified one in its own ns. Returns the var iff genuinely defined, else nil —
 ;; never interns an empty cell (var-cell-lookup is non-creating).
+;; resolve `sym` in the current ns: a qualified ns part is read as an :as alias
+;; (then a real ns); an unqualified name resolves in the current ns, its :refers,
+;; then clojure.core. (ns-resolve does the same against an explicit ns.)
 (define (jolt-resolve sym)
-  (let* ((sns (symbol-t-ns sym)) (nm (symbol-t-name sym))
+  (let* ((cns (chez-current-ns))
+         (sns (symbol-t-ns sym)) (nm (symbol-t-name sym))
          (c (if (string? sns)
-                (var-cell-lookup sns nm)
-                (or (var-cell-lookup (chez-current-ns) nm)
+                (var-cell-lookup (or (chez-resolve-alias cns sns) sns) nm)
+                (or (var-cell-lookup cns nm)
+                    (let ((ref (chez-resolve-refer cns nm))) (and ref (var-cell-lookup ref nm)))
                     (var-cell-lookup "clojure.core" nm)))))
     (if (and c (var-cell-defined? c)) c jolt-nil)))