mescc: Change --align to --align=functions, --align=globals.

This makes function alignment optional and disables function alignment
when using MesCC-Tools 0.5.2 (numbered architecture).

* module/mescc.scm (parse-opts): Make --align take a value.
* module/mescc/mescc.scm (mescc:compile, infos->hex2): Parse it and pass
it as renamed #:align keyword argument to ...
* module/mescc/M1.scm (infos->M1): ...here.  Rename parameter align? to
align, pass it to...
(info->M1): ...here.  Likewise.  Use it to make function alignment
optional.

doc/mes.texi

@@ -876,8 +876,9 @@ The @var{option}s can be among the following:
 
 @table @code
 
-@item --align
-align globals
+@item --align=@var{symbol}
+align @var{symbol}, the default is @code{functions}; other valid values
+are: @code{globals}.
 
 @item --base-address=ADRRESS
 use BaseAddress ADDRESS [0x1000000]

module/mescc.scm

@@ -58,7 +58,7 @@
 
 (define (parse-opts args)
   (let* ((option-spec
-          '((align)
+          '((align (value #t))
             (arch (value #t))
             (assemble (single-char #\c))
             (base-address (value #t))
@@ -103,7 +103,7 @@ Usage: mescc [OPTION]... FILE...
 C99 compiler in Scheme for bootstrapping the GNU system.
 
 Options:
-  --align             align globals
+  --align=SYMBOL      align SYMBOL {functions,globals,none} [functions]
   --arch=ARCH         compile for ARCH [~a]
   --kernel=ARCH       compile for KERNEL [~a]
   -dumpmachine        display the compiler's target machine

module/mescc/M1.scm

@@ -35,9 +35,9 @@
             infos->M1
             M1:merge-infos))
 
-(define* (infos->M1 file-name infos #:key align? verbose?)
+(define* (infos->M1 file-name infos #:key align verbose?)
   (let ((info (fold M1:merge-infos (make <info>) infos)))
-    (info->M1 file-name info #:align? align? #:verbose? verbose?)))
+    (info->M1 file-name info #:align align #:verbose? verbose?)))
 
 (define (M1:merge-infos o info)
   (clone info
@@ -113,14 +113,16 @@
 (define (global-extern? o)
   (and=> (global:storage o) (cut eq? <> 'extern)))
 
-(define* (info->M1 file-name o #:key align? verbose?)
+(define* (info->M1 file-name o #:key align verbose?)
   (let* ((functions (.functions o))
          (function-names (map car functions))
          (globals (.globals o))
          (globals (filter (negate (compose global-extern? cdr)) globals))
          (strings (filter global-string? globals))
          (strings (map car strings))
-         (reg-size (type:size (assoc-ref (.types o) "*"))))
+         (reg-size (type:size (assoc-ref (.types o) "*")))
+         (align-functions? (memq 'functions align))
+         (align-globals? (memq 'globals align)))
     (define (string->label o)
       (let ((index (list-index (lambda (s) (equal? s o)) strings)))
         (if index
@@ -207,8 +209,11 @@
           (newline))
         (when verbose?
           (display (string-append "    :" name "\n") (current-error-port)))
+        (display "\n\n")
+        (when align-functions?
           ;; "<" aligns to multiple of 4 Bytes.
-        (display (string-append "\n\n<\n:" name "\n"))
+          (display "<\n"))
+        (display (string-append ":" name "\n"))
         (for-each line->M1 (apply append text))))
     (define (write-global o)
       (define (labelize o)
@@ -223,7 +228,7 @@
                     (else (string-append "&" label))))))
       (define (display-align size)
         (let ((alignment (- reg-size (modulo size reg-size))))
-          (when (and align? (> reg-size alignment 0))
+          (when (and align-globals? (> reg-size alignment 0))
             (display " ")
             (display-join (map text->M1 (map (const 0) (iota alignment))) " "))
           #t))

module/mescc/mescc.scm

@@ -79,11 +79,16 @@
                              (else (replace-suffix input-base ".s"))))
          (infos (map (cut file->info options <>) files))
          (verbose? (count-opt options 'verbose))
-         (align? (option-ref options 'align #f)))
+         (numbered-arch? (option-ref options 'numbered-arch? #f))
+         (align (filter-map (multi-opt 'align) options))
+         (align (if (null? align) '(functions) (map string->symbol align)))
+         (align (if (not numbered-arch?) align
+                    ;; function alignment not supported by MesCC-Tools 0.5.2
+                    (filter (negate (cut eq? <> 'functions)) align))))
     (when verbose?
       (stderr "dumping: ~a\n" M1-file-name))
     (with-output-to-file M1-file-name
-      (cut infos->M1 M1-file-name infos #:align? align? #:verbose? verbose?))
+      (cut infos->M1 M1-file-name infos #:align align #:verbose? verbose?))
     M1-file-name))
 
 (define (file->info options file-name)
@@ -168,11 +173,16 @@
          (options (acons 'compile #t options)) ; ugh
          (options (acons 'output hex2-file-name options))
          (verbose? (count-opt options 'verbose))
-         (align? (option-ref options 'align #f)))
+         (numbered-arch? (option-ref options 'numbered-arch? #f))
+         (align (filter-map (multi-opt 'align) options))
+         (align (if (null? align) '(functions) (map string->symbol align)))
+         (align (if (not numbered-arch?) align
+                    ;; function alignment not supported by MesCC-Tools 0.5.2
+                    (filter (negate (cut eq? <> 'functions)) align))))
     (when verbose?
       (stderr "dumping: ~a\n" M1-file-name))
     (with-output-to-file M1-file-name
-      (cut infos->M1 M1-file-name infos #:align? align?))
+      (cut infos->M1 M1-file-name infos #:align align))
     (or (M1->hex2 options (list M1-file-name))
         (exit 1))))