1.0.17.20: NIL is a legal function name (regression 1.0.13.38)

[sbcl.git] / src / compiler / mips / call.lisp

diff --git a/src/compiler/mips/call.lisp b/src/compiler/mips/call.lisp
index 8035520..578da61 100644 (file)
--- a/src/compiler/mips/call.lisp
+++ b/src/compiler/mips/call.lisp
@@ -652,7 +652,8 @@ default-value-8
      (:vop-var vop)
      (:info ,@(unless (or variable (eq return :tail)) '(arg-locs))
             ,@(unless variable '(nargs))
-            ,@(when (eq return :fixed) '(nvals)))
+            ,@(when (eq return :fixed) '(nvals))
+            step-instrumenting)
 
      (:ignore ,@(unless (or variable (eq return :tail)) '(arg-locs))
               ,@(unless variable '(args)))
@@ -696,6 +697,8 @@ default-value-8
      ,@(when (eq return :fixed)
          '((:temporary (:scs (descriptor-reg) :from :eval) move-temp)))
 
+     (:temporary (:scs (descriptor-reg) :to :eval) stepping)
+
      ,@(unless (eq return :tail)
          '((:temporary (:scs (non-descriptor-reg)) temp)
            (:temporary (:sc control-stack :offset nfp-save-offset) nfp-save)))
@@ -710,6 +713,7 @@ default-value-8
        (let* ((cur-nfp (current-nfp-tn vop))
               ,@(unless (eq return :tail)
                   '((lra-label (gen-label))))
+              (step-done-label (gen-label))
               (filler
                (remove nil
                        (list :load-nargs
@@ -775,7 +779,29 @@ default-value-8
                                          (move cfp-tn csp-tn)))
                                (trace-table-entry trace-table-call-site))))
                       ((nil)
-                       (inst nop))))))
+                       (inst nop)))))
+                (insert-step-instrumenting (callable-tn)
+                  ;; Conditionally insert a conditional trap:
+                  (when step-instrumenting
+                    ;; Get the symbol-value of SB!IMPL::*STEPPING*
+                    (inst lw stepping null-tn
+                          (- (+ symbol-value-slot
+                                (truncate (static-symbol-offset 'sb!impl::*stepping*)
+                                          n-word-bytes))
+                             other-pointer-lowtag))
+                    ;; If it's not NIL, trap.
+                    (inst beq stepping null-tn step-done-label)
+                    (inst nop)
+                    ;; CONTEXT-PC will be pointing here when the
+                    ;; interrupt is handled, not after the BREAK.
+                    (note-this-location vop :step-before-vop)
+                    ;; Construct a trap code with the low bits from
+                    ;; SINGLE-STEP-AROUND-TRAP and the high bits from
+                    ;; the register number of CALLABLE-TN.
+                    (inst break 0 (logior single-step-around-trap
+                                          (ash (reg-tn-encoding callable-tn)
+                                               5)))
+                    (emit-label step-done-label))))
 
            ,@(if named
                  `((sc-case name
@@ -789,6 +815,10 @@ default-value-8
                             (- (ash (tn-offset name) word-shift)
                                other-pointer-lowtag))
                       (do-next-filler)))
+                   ;; The step instrumenting must be done after
+                   ;; FUNCTION is loaded, but before ENTRY-POINT is
+                   ;; calculated.
+                   (insert-step-instrumenting name-pass)
                    (inst lw entry-point name-pass
                          (- (ash fdefn-raw-addr-slot word-shift)
                             other-pointer-lowtag))
@@ -808,6 +838,10 @@ default-value-8
                          (- (ash closure-fun-slot word-shift)
                             fun-pointer-lowtag))
                    (do-next-filler)
+                   ;; The step instrumenting must be done before
+                   ;; after FUNCTION is loaded, but before ENTRY-POINT
+                   ;; is calculated.
+                   (insert-step-instrumenting function)
                    (inst addu entry-point function
                          (- (ash simple-fun-code-offset word-shift)
                             fun-pointer-lowtag))))
@@ -1249,3 +1283,27 @@ default-value-8
   (frob unknown-key-arg-error unknown-key-arg-error
     sb!c::%unknown-key-arg-error key)
   (frob nil-fun-returned-error nil-fun-returned-error nil fun))
+
+;;; Single-stepping
+
+(define-vop (step-instrument-before-vop)
+  (:temporary (:scs (descriptor-reg)) stepping)
+  (:policy :fast-safe)
+  (:vop-var vop)
+  (:generator 3
+    ;; Get the symbol-value of SB!IMPL::*STEPPING*
+    (inst lw stepping null-tn
+          (- (+ symbol-value-slot
+                (truncate (static-symbol-offset 'sb!impl::*stepping*)
+                          n-word-bytes))
+             other-pointer-lowtag))
+    ;; If it's not NIL, trap.
+    (inst beq stepping null-tn DONE)
+    (inst nop)
+    ;; CONTEXT-PC will be pointing here when the interrupt is handled,
+    ;; not after the BREAK.
+    (note-this-location vop :step-before-vop)
+    ;; CALLEE-REGISTER-OFFSET isn't needed for before-traps, so we
+    ;; can just use a bare SINGLE-STEP-BEFORE-TRAP as the code.
+    (inst break 0 single-step-before-trap)
+    DONE))