src/compiler/xref.lisp

   1 ;;;; xref facility
   2
   3 ;;;; This software is part of the SBCL system. See the README file for
   4 ;;;; more information.
   5 ;;;;
   6 ;;;; This software is derived from the CMU CL system, which was
   7 ;;;; written at Carnegie Mellon University and released into the
   8 ;;;; public domain. The software is in the public domain and is
   9 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
  10 ;;;; files for more information.
  11
  12 (in-package "SB!C")
  13
  14 (defvar *xref-kinds* '(:binds :calls :sets :references :macroexpands))
  15
  16 (defun record-component-xrefs (component)
  17   (declare (type component component))
  18   (when (policy *lexenv* (zerop store-xref-data))
  19     (return-from record-component-xrefs))
  20   (do ((block (block-next (component-head component)) (block-next block)))
  21       ((null (block-next block)))
  22     (let* ((this-cont (block-start block))
  23            (last (block-last block)))
  24       (flet ((handle-node (functional)
  25                ;; Record xref information for all nodes in the block.
  26                ;; Note that this code can get executed several times
  27                ;; for the same block, if the functional is referenced
  28                ;; from multiple XEPs.
  29                (loop for node = (ctran-next this-cont)
  30                      then (ctran-next (node-next node))
  31                      until (eq node last)
  32                      do (record-node-xrefs node functional))
  33                ;; Properly record the deferred macroexpansion information
  34                ;; that's been stored in the block.
  35                (dolist (xref-data (block-macroexpands block))
  36                  (record-xref :macroexpands
  37                               (car xref-data)
  38                               ;; We use the debug-name of the functional
  39                               ;; as an identifier. This works quite nicely,
  40                               ;; except for (fast/slow)-methods with non-symbol,
  41                               ;; non-number eql specializers, for which
  42                               ;; the debug-name doesn't map exactly
  43                               ;; to the fdefinition of the method.
  44                               functional
  45                               nil
  46                               (cdr xref-data)))))
  47         (call-with-block-external-functionals block #'handle-node)))))
  48
  49 (defun call-with-block-external-functionals (block fun)
  50   (let* ((functional (block-home-lambda block))
  51          (seen nil))
  52     (labels ((local-function-name-p (name)
  53                (and (consp name)
  54                     (member (car name)
  55                             '(flet labels lambda))))
  56              (handle-functional (functional)
  57                ;; If a functional looks like a global function (has a
  58                ;; XEP, isn't a local function or a lambda) record xref
  59                ;; information for it. Otherwise recurse on the
  60                ;; home-lambdas of all references to the functional.
  61                (when (eq (functional-kind functional) :external)
  62                  (let ((entry (functional-entry-fun functional)))
  63                    (when entry
  64                      (let ((name (functional-debug-name entry)))
  65                        (unless (local-function-name-p name)
  66                          (return-from handle-functional
  67                            (funcall fun entry)))))))
  68                ;; Recurse only if we haven't already seen the
  69                ;; functional.
  70                (unless (member functional seen)
  71                  (push functional seen)
  72                  (dolist (ref (functional-refs functional))
  73                    (handle-functional (node-home-lambda ref))))))
  74       (unless (or (eq :deleted (functional-kind functional))
  75                   ;; If the block came from an inlined global
  76                   ;; function, ignore it.
  77                   (and (functional-inlinep functional)
  78                        (symbolp (functional-debug-name functional))))
  79         (handle-functional functional)))))
  80
  81 (defun record-node-xrefs (node context)
  82   (declare (type node node))
  83   (etypecase node
  84     ((or creturn cif entry mv-combination cast))
  85     (combination
  86      ;; Record references to globals made using SYMBOL-VALUE.
  87      (let ((fun (principal-lvar-use (combination-fun node)))
  88            (arg (car (combination-args node))))
  89        (when (and (ref-p fun) (eq 'symbol-value (leaf-%source-name (ref-leaf fun)))
  90                   (constant-lvar-p arg) (symbolp (lvar-value arg)))
  91          (record-xref :references (lvar-value arg) context node nil))))
  92     (ref
  93      (let ((leaf (ref-leaf node)))
  94        (typecase leaf
  95          (global-var
  96           (let* ((name (leaf-debug-name leaf)))
  97             (case (global-var-kind leaf)
  98               ;; Reading a special
  99               (:special
 100                (record-xref :references name context node nil))
 101               ;; Calling a function
 102               (:global-function
 103                (record-xref :calls name context node nil)))))
 104          ;; Inlined global function
 105          (clambda
 106           (when (functional-inlinep leaf)
 107             (let ((name (leaf-debug-name leaf)))
 108               ;; FIXME: we should store the original var into the
 109               ;; functional when creating inlined-functionals, so that
 110               ;; we could just check whether it was a global-var,
 111               ;; rather then needing to guess based on the debug-name.
 112               (when (or (symbolp name)
 113                         ;; Any non-SETF non-symbol names will
 114                         ;; currently be either non-functions or
 115                         ;; internals.
 116                         (and (consp name)
 117                              (equal (car name) 'setf)))
 118                 ;; TODO: a WHO-INLINES xref-kind could be useful
 119                 (record-xref :calls name context node nil)))))
 120          ;; Reading a constant
 121          (constant
 122           (let* ((name (constant-%source-name leaf)))
 123             (record-xref :references name context node nil))))))
 124     ;; Setting a special variable
 125     (cset
 126      (let* ((var (set-var node)))
 127        (when (and (global-var-p var)
 128                   (eq :special (global-var-kind var)))
 129          (record-xref :sets
 130                       (leaf-debug-name var)
 131                       context
 132                       node
 133                       nil))))
 134     ;; Binding a special variable
 135     (bind
 136      (let ((vars (lambda-vars (bind-lambda node))))
 137        (dolist (var vars)
 138          (when (lambda-var-specvar var)
 139            (record-xref :binds
 140                         (lambda-var-%source-name var)
 141                         context
 142                         node
 143                         nil)))))))
 144
 145 (defun internal-name-p (what)
 146   ;; Don't store XREF information for internals. We define as internal
 147   ;; anything named only by symbols from either implementation
 148   ;; packages, COMMON-LISP or KEYWORD. The last one is useful for
 149   ;; example when dealing with ctors.
 150   (typecase what
 151     (list
 152      (every #'internal-name-p what))
 153     (symbol
 154      (member (symbol-package what)
 155              (load-time-value (list* (find-package "COMMON-LISP")
 156                                      (find-package "KEYWORD")
 157                                      (remove-if-not
 158                                       (lambda (package)
 159                                         (= (mismatch "SB!"
 160                                                      (package-name package))
 161                                            3))
 162                                       (list-all-packages))))))
 163     (t t)))
 164
 165 (defun record-xref (kind what context node path)
 166   (unless (internal-name-p what)
 167     (let ((path (reverse
 168                  (source-path-original-source
 169                   (or path
 170                       (node-source-path node))))))
 171       (push (list what path)
 172             (getf (functional-xref context) kind)))))
 173
 174 (defun record-macroexpansion (what block path)
 175   (unless (internal-name-p what)
 176     (push (cons what path) (block-macroexpands block))))
 177
 178 ;;; Pack the xref table that was stored for a functional into a more
 179 ;;; space-efficient form, and return that packed form.
 180 (defun pack-xref-data (xref-data)
 181   (when xref-data
 182     (let ((array (make-array (length *xref-kinds*))))
 183       (loop for key in *xref-kinds*
 184             for i from 0
 185             for values = (remove-duplicates (getf xref-data key)
 186                                             :test #'equal)
 187             for flattened = (reduce #'append values :from-end t)
 188             collect (setf (aref array i)
 189                           (when flattened
 190                             (make-array (length flattened)
 191                                         :initial-contents flattened))))
 192       array)))