From: Luke Lau <luke_lau@icloud.com>
Date: Wed, 24 Jul 2019 23:59:30 +0000 (+0100)
Subject: Merge branch 'master' of lukelau.me:/srv/git/scheme
X-Git-Url: http://git.lukelau.me/?p=scheme.git;a=commitdiff_plain;h=5d4aafc1235538212989893f15006acc5d7d8f03;hp=a006c661a194672c2d8f5730d3c207dd083ddbf0

Merge branch 'master' of lukelau.me:/srv/git/scheme
---

diff --git a/.gitignore b/.gitignore
index e4e5f6c..02cfc43 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 *~
+TAGS
diff --git a/codegen.scm b/codegen.scm
index 571f1ef..78ebbad 100644
--- a/codegen.scm
+++ b/codegen.scm
@@ -1,6 +1,8 @@
 (load "typecheck.scm")
 (load "ast.scm")
 
+(define target 'darwin)
+
 (define (emit . s)
   (begin
     (apply printf s)
@@ -47,6 +49,8 @@
   (emit "not %rax")
   (emit "andq $1, %rax"))
 
+; 'write file handle addr-string num-bytes
+     
 (define (codegen-print x si env)
   (codegen-expr x si env) ; x should be a static-string, producing a label
 
@@ -63,10 +67,17 @@
   (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 %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 %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)
@@ -108,6 +119,7 @@
 ; 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))))
@@ -120,7 +132,7 @@
 		(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)
@@ -187,6 +199,11 @@
     (emit "pop %rbp") ; restore caller's base pointer
     (emit "ret")))
 
+(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))
@@ -232,7 +249,7 @@
     ('bool-literal (emit "movq $~a, %rax" (if e 1 0)))
     ('int-literal (emit "movq $~a, %rax" e))
     
-    ('static-string (emit "lea ~a, %rax" (cadr e))) ; move label
+    ('static-string (codegen-string (cadr e)))
 
     (else (error #f "don't know how to codegen this"))))
 
@@ -379,7 +396,9 @@
 
 					; 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 ".data")
@@ -389,13 +408,21 @@
 
     (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:
diff --git a/main.scm b/main.scm
index 53daa7c..ce9241a 100644
--- a/main.scm
+++ b/main.scm
@@ -1,7 +1,34 @@
 (load "codegen.scm")
 
+; returns (os filename)
+(define (parse-args)
+  (define (parse-os x)
+    (if (null? x) 'darwin ; todo: replace this with the os
+					; it was compiled with
+	(if
+	 (or (equal? (car x) "-t")
+	     (equal? (car x) "--target"))
+	 (case (cadr x)
+	   ("darwin" 'darwin)
+	   ("linux"  'linux)
+	   (else (error #f "unknown os")))	   
+	 (parse-os (cdr x)))))
+  (define (parse-file x)
+    (if (null? x) 'stdin
+	(if
+	 (or (equal? (car x) "-t")
+	     (equal? (car x) "--target"))
+	 (parse-file (cddr x))
+	 (car x))))
+  (let ((args (cdr (command-line))))
+    (list (parse-os args) (parse-file args))))
+
+
+(define target (car (parse-args)))
+(define file (cadr (parse-args)))
+
 (compile-to-binary
- (if (> (length (command-line)) 1)
-     (call-with-input-file (cadr (command-line)) read)
-     (read))
- "a.out")
+ (if (eqv? file 'stdin)
+     (read)
+     (call-with-input-file file read))
+ "a.out" target)
diff --git a/tests.scm b/tests.scm
index 168cf66..89ca852 100644
--- a/tests.scm
+++ b/tests.scm
@@ -19,13 +19,13 @@
 (define (test-prog prog exit-code)
   (display prog)
   (newline)
-  (compile-to-binary prog "/tmp/test-prog")
+  (compile-to-binary prog "/tmp/test-prog" 'darwin)
   (test (system "/tmp/test-prog") exit-code))
 
 (define (test-prog-stdout prog output)
   (display prog)
   (newline)
-  (compile-to-binary prog "/tmp/test-prog")
+  (compile-to-binary prog "/tmp/test-prog" 'darwin)
   (system "/tmp/test-prog > /tmp/test-output.txt")
   (let ((str (read-file "/tmp/test-output.txt")))
     (test str output)))