Fixes #11.

a86/interp.rkt

@@ -37,8 +37,6 @@
 (define fclose
   (get-ffi-obj "fclose" (ffi-lib #f) (_fun _pointer _-> _void)))
 
-(define fmt (if (eq? (system-type 'os) 'macosx) 'macho64 'elf64))
-
 ;; WARNING: The heap is re-used, so make sure you're done with it
 ;; before calling asm-interp again
 (define *heap*
@@ -208,8 +206,14 @@
 ;; run nasm on t.s to create t.o
 (define (nasm t.s t.o)
   (define err-port (open-output-string))
+  (define fmt (if (eq? (system-type 'os) 'macosx) 'macho64 'elf64))
+  (define prefix
+    (if (eq? (system-type 'os) 'macosx)
+        "'_'"
+        "''"))
+
   (unless (parameterize ((current-error-port err-port))
-            (system (format "nasm -f ~a ~a -o ~a" fmt t.s t.o)))
+            (system (format "nasm -f ~a --gprefix ~a ~a -o ~a" fmt prefix t.s t.o)))
     (nasm:error (get-output-string err-port))))
 
 (struct exn:ld exn:fail:user ())

a86/printer.rkt

@@ -25,26 +25,17 @@
 (define current-extern-labels (make-parameter '()))
 
 ;; Label -> String
-;; prefix with _ for Mac
-(define label-symbol->string
-  (match (system-type 'os)
-    ['macosx
-     (λ (s) (string-append "$_" (symbol->string s)))]
-    [_
-     (λ (s)
-       (if (and (current-shared?) (memq s (current-extern-labels)))
-           ; hack for ELF64 shared libraries in service of
-           ; calling external functions in asm-interp
-           (string-append "$" (symbol->string s) " wrt ..plt")
-           (string-append "$" (symbol->string s))))]))
+(define (label-symbol->string s)
+  ;; This should maybe be handled specially in the printing of Call rather
+  ;; than in every label...
+  (if (and (eq? (system-type 'os) 'unix) (current-shared?) (memq s (current-extern-labels)))
+      ; hack for ELF64 shared libraries in service of
+      ; calling external functions in asm-interp
+      (string-append "$" (symbol->string s) " wrt ..plt")
+      (string-append "$" (symbol->string s))))
 
-(define extern-label-decl-symbol->string
-  (match (system-type 'os)
-    ['macosx
-     (λ (s) (string-append "$_" (symbol->string s)))]
-    [_
-     (λ (s)
-       (string-append "$" (symbol->string s)))]))
+(define (extern-label-decl-symbol->string s)
+  (string-append "$" (symbol->string s)))
 
 ;; Instruction -> String
 (define (common-instruction->string i)

a86/test/interp.rkt

@@ -0,0 +1,9 @@
+#lang racket
+(require rackunit "../ast.rkt" "../interp.rkt")
+
+(check-equal?
+ (asm-interp (prog (Global 'entry)
+                   (Label 'entry)
+                   (Mov 'rax 42)
+                   (Ret)))
+ 42)