(emit "not %rcx") ; -%rcx = strlen + 1
(emit "dec %rcx")
- (emit "mov %rcx, %rdx") ; number of bytes
- (emit "mov %rbx, %rsi") ; addr of string
- (emit "mov $1, %rax") ; file handle 1 (stdout)
- (emit "mov $1, %rdi") ; syscall 1 (write)
+ (case target
+ ('darwin
- (emit "movq %rax, %rsi") ; string addr
++ (emit "movq %rbx, %rsi") ; string addr
+ (emit "movq %rcx, %rdx") ; num bytes
+ (emit "movq $1, %rdi") ; file handle (stdout)
+ (emit "movq $0x2000004, %rax")) ; syscall 4 (write)
+ ('linux
- (emit "mov %rax, %rsi") ; string addr
++ (emit "mov %rbx, %rsi") ; string addr
+ (emit "mov %rcx, %rdx") ; num bytes
+ (emit "mov $1, %rax") ; file handle (stdout)
+ (emit "mov $1, %rdi"))) ; syscall 1 (write)
(emit "syscall"))
(define (range s n)
(set! cur-lambda (+ 1 cur-lambda))
(format "_lambda~a" (- cur-lambda 1)))
-)
+ ; a closure on the heap looks like:
+ ; 0-x x+0 x+4 x+12 x+20
+ ; label #vars var1.... var2.... var3....
++
+ (define (codegen-closure label captured si env)
+ (let* ((heap-offsets (range 4 (length captured))) ; 4, 12, 20, etc.
+ (inner-si (- si (* (length captured) wordsize))))
+ (emit "movl $~a, (heap_start)")
+ (emit "add $4, (heap_start)")
+ (for-each (lambda (var-name new-offset)
+ (emit "movq ~a(%rbp), ~a(heap_start)" ; todo: do we need to copy this?
+ (cdr (assoc var-name env))
+ new-offset)
+ (emit "add $8, (heap_start)")
+ captured
+ stack-offsets)
++)))
; for now we can only call closures
(define (codegen-call closure args si env)
+ ; (codegen-expr closure si env)
(when (not (eq? (ast-type closure) 'closure))
(error #f (format "~a is not a closure" closure)))
(let* ((captured (caddr closure))
(emit "pop %rbp") ; restore caller's base pointer
(emit "ret")))
- ('linux (emit "movq $~a, %rax" label))))
+(define (codegen-string label)
+ (case target
+ ('darwin (emit "movq ~a@GOTPCREL(%rip), %rax" label))
++ ('linux (emit "lea $~a, %rax" label))))
+
(define cur-label 0)
(define (fresh-label)
(set! cur-label (+ 1 cur-label))
; exit syscall
(emit "mov %rax, %rdi")
- (emit "mov $60, %rax")
+ (case target
+ ('darwin (emit "movq $0x2000001, %rax"))
+ ('linux (emit "mov $60, %rax")))
(emit "syscall")
- (emit "\t.data")
+ (emit ".data")
- (for-each codegen-string-data strings)))
+ (emit "heap_start:")
+ (emit "\t.quad 0")
+
+ (for-each emit-string-data strings)))
-(define (compile-to-binary program output)
+(define (compile-to-binary program output t)
+ (set! target t)
(when (not (eq? (typecheck program) 'int)) (error #f "not an int"))
(let ([tmp-path "/tmp/a.s"])
(when (file-exists? tmp-path) (delete-file tmp-path))
(with-output-to-file tmp-path
(lambda () (codegen program)))
- (system (format "clang -nostdlib /tmp/a.s -o ~a" output))))
+
+ (case target
+ ('darwin
+ (system "as /tmp/a.s -o /tmp/a.o")
+ (system (format "ld /tmp/a.o -e _start -macosx_version_min 10.14 -static -o ~a" output)))
+ ('linux
+ (system "as /tmp/a.s -o /tmp/a.o")
+ (system (format "ld /tmp/a.o -o ~a" output))))))
+
+ ; NOTES
+ ; syscalls in linux use the following arguments for syscall instruction:
+ ; %rax = syscall #
+ ; %rdi = 1st arg
+ ; %rsi = 2nd arg
+ ; %rdx = 3rd arg
+ ; %r10 = 4th arg
+ ; %r8 = 5th arg
+ ; %r9 = 6th arg