read the feature flags in sextest in the way sexc does

sextest resolves #+ and #- itself -- it reads the program and prints
what survives to sexc -- so a flag spelling it does not recognise
decides which branch gets compiled

semen.scm

@@ -140,91 +140,28 @@
   (cons (copy-form-source! form `(typedef ,target ,new-type)) acc))
 
 ;;; Fn processing
-;;;
-;;; A string as the first body form is a docstring. In the generated
-;;; C code it will be placed as a C commentary just before the function
-;;; definition (actually that works for all blocky things: enum, struct, union as well).
-
-(define (fn-header-length fn-form)
-  (if (memq (first fn-form) '(pub extern)) 5 4))
-
-(define (fn-core form)
-  ;; The (fn name args rettype . body) list, without pub/extern
-  (if (memq (first form) '(pub extern))
-      (cdr form)
-      form))
-
-(define (take-leading-docstring forms)
-  ;; If FORMS starts with a string, possibly after comment forms, return
-  ;; that string and FORMS without it. Otherwise #f and FORMS unchanged
-  (let loop ((fs forms) (prefix (list)))
-    (match fs
-      (() (values #f forms))
-      (((and cmt ('comment . _)) . rest)
-       (loop rest (cons cmt prefix)))
-      (((? string? doc) . rest)
-       (values doc (append (reverse prefix) rest)))
-      (_ (values #f forms)))))
-
-(define (extract-fn-docstring fn-form)
-  (let ((lift
-         (lambda (proto body)
-           (let-values (((doc rest) (take-leading-docstring body)))
-             (if doc
-                 (values doc (copy-form-source! fn-form (append proto rest)))
-                 (values #f fn-form))))))
-    (match fn-form
-      (('pub 'fn name args ret . body)
-       (lift `(pub fn ,name ,args ,ret) body))
-      (('extern 'fn name args ret . body)
-       (lift `(extern fn ,name ,args ,ret) body))
-      (('fn name args ret . body)
-       (lift `(fn ,name ,args ,ret) body))
-      (_ (values #f fn-form)))))
-
-(define (extract-aggregate-docstring form)
-  ;; A string immediately after the name is the docstring; comments
-  ;; between name and fields are not skipped, they already confuse the
-  ;; writer
-  (match form
-    (('pub (and kind (or 'struct 'union 'enum))
-           (? symbol? name) (? string? doc) . rest)
-     (values doc (copy-form-source! form `(pub ,kind ,name ,@rest))))
-    (((and kind (or 'struct 'union 'enum))
-      (? symbol? name) (? string? doc) . rest)
-     (values doc (copy-form-source! form `(,kind ,name ,@rest))))
-    (_ (values #f form))))
-
-(define (with-docstring doc form acc)
-  ;; acc is newest-first; FORM is consed last so the final reverse
-  ;; emits the comment immediately before the declaration
-  (cons form
-        (if doc
-            (cons (list 'comment doc) acc)
-            acc)))
 
 (define (strip-fn-header-comments fn-form)
-  ;; ([pub|extern] fn name arglist rettype). Comments in the body are
-  ;; left in place as ordinary statements and preserved into the
-  ;; generated C.
-  (strip-header-comments fn-form (fn-header-length fn-form)))
+  ;; ([pub|extern] fn name arglist rettype)
+  (strip-header-comments fn-form
+                         (if (memq (car fn-form) '(pub extern)) 5 4)))
 
 (define (process-fn sex-fn-raw acc)
-  (let-values (((doc sex-fn)
-                (extract-fn-docstring (strip-fn-header-comments sex-fn-raw))))
-    (let* ((expanded (macro-expand sex-fn))
-           (env (make-hash-table))
-           (processed
-            (walk-form
-             expanded
-             fn-walker
-             (begin
-               (set! (hash-table-ref env :fn-name) (sex-fn-name expanded))
-               (set! (hash-table-ref env :lambda-counter) 0)
-               (set! (hash-table-ref env :lambda-aux-code) (list))
-               env))))
-      (with-docstring doc processed
-                      (append (hash-table-ref env :lambda-aux-code) acc)))))
+  (let* ((sex-fn (strip-fn-header-comments sex-fn-raw))
+         (expanded (macro-expand sex-fn))
+         (env (make-hash-table))
+         (processed
+          (walk-form
+           expanded
+           fn-walker
+           (begin
+             (set! (hash-table-ref env :fn-name) (sex-fn-name expanded))
+             (set! (hash-table-ref env :lambda-counter) 0)
+             (set! (hash-table-ref env :lambda-aux-code) (list))
+             env))))
+
+    (cons processed
+          (append (hash-table-ref env :lambda-aux-code) acc))))
 
 (define (fn-walker form env)
   (if (eq? 'lambda (car form))
@@ -255,9 +192,8 @@
 
 ;;; Record the named structs, unions and enums in the type database
 (define (process-struct sex-struct acc)
-  (let-values (((doc form) (extract-aggregate-docstring sex-struct)))
-    (register-aggregate! form)
-    (with-docstring doc form acc)))
+  (register-aggregate! sex-struct)
+  (cons sex-struct acc))
 
 (define (register-aggregate! form)
   (let* ((f (if (eq? (car form) 'pub) (cdr form) form))
@@ -282,36 +218,45 @@
   "The `form` must be toplevel.
 Returns #f if the form is not a function, returns the form otherwise"
   (match form
-    ((or ('fn . _)
-         ('pub 'fn . _)
-         ('extern 'fn . _)) form)
+    ((fn . _) form)
+    ((pub fn . _) form)
     (else #f)))
 
 (define (sex-fn-public? fn-form)
-  (eq? (first fn-form) 'pub))
-
-(define (sex-fn-name fn-form)
-  (assert (sex-fn? fn-form)
-          (fmt #f "Form " fn-form " is not a function"))
-  (second (fn-core fn-form)))
-
-(define (sex-fn-arglist fn-form)
-  (assert (sex-fn? fn-form)
-          (fmt #f "Form " fn-form " is not a function"))
-  (third (fn-core fn-form)))
+  (eq? (car fn-form) 'pub))
 
 (define (sex-fn-return-type fn-form)
   (assert (sex-fn? fn-form)
           (fmt #f "Form " fn-form " is not a function"))
-  (fourth (fn-core fn-form)))
+  (if (sex-fn-public? fn-form)
+      (third fn-form)
+      (second fn-form)))
+
+(define (sex-fn-name fn-form)
+  (assert (sex-fn? fn-form)
+          (fmt #f "Form " fn-form " is not a function"))
+  (if (sex-fn-public? fn-form)
+      (fourth fn-form)
+      (third fn-form)))
+
+(define (sex-fn-arglist fn-form)
+  (assert (sex-fn? fn-form)
+          (fmt #f "Form " fn-form " is not a function"))
+  (if (sex-fn-public? fn-form)
+      (fifth fn-form)
+      (fourth fn-form)))
 
 (define (sex-fn-prototype fn-form)
   "Returns all except body"
   (assert (sex-fn? fn-form)
           (fmt #f "Form " fn-form " is not a function"))
-  (take fn-form (fn-header-length fn-form)))
+  (if (sex-fn-public? fn-form)
+      (take fn-form 5)
+      (take fn-form 4)))
 
 (define (sex-fn-body fn-form)
   (assert (sex-fn? fn-form)
           (fmt #f "Form " fn-form " is not a function"))
-  (drop fn-form (fn-header-length fn-form)))
+  (if (sex-fn-public? fn-form)
+      (drop fn-form 5)
+      (drop fn-form 4)))

sex-modules.scm

@@ -8,7 +8,6 @@
   (chicken process-context)
   (chicken string)
   fmt
-  matchable
   reader
   srfi-1
   utils)
@@ -72,35 +71,28 @@
      (list)
      raw-forms)))
 
-(define (public-fn-interface raw-form)
-  ;; (pub fn name args ret . body) -> prototype, keeping a docstring so
-  ;; the importer can emit it above the declaration
-  (let ((form (strip-header-comments raw-form 5)))
-    (match form
-      (('pub 'fn name args ret)
-       form)
-      (('pub 'fn name args ret ('comment . _) . rest)
-       (public-fn-interface `(pub fn ,name ,args ,ret ,@rest)))
-      (('pub 'fn name args ret (? string? doc) . _)
-       `(pub fn ,name ,args ,ret ,doc))
-      (('pub 'fn name args ret . _)
-       `(pub fn ,name ,args ,ret)))))
-
 ;;; TODO: use semen facilities to analyze modules
 (define (process-public-interface-form form acc)
-  (match form
-    ;; Reduced to a prototype, still `pub', so the importer declares it
-    ;; with external linkage
-    (('pub 'fn . _)
-     (cons (copy-form-source! form (public-fn-interface form)) acc))
-    (('pub 'var . _)
-     (match-let ((('pub 'var name type . _) (strip-header-comments form 4)))
-       (cons (copy-form-source! form `(extern var ,name ,type)) acc)))
-    (('pub (or 'define 'defmacro 'enum 'import 'include 'struct 'typedef 'union) . _)
-     (cons (copy-form-source! form (cdr form)) acc))
-    (('pub . _)
-     (sex-error form "pub must be followed by a definition" form))
-    (_ acc)))
+  (case (car form)
+    ((pub)
+     (case (cadr form)
+       ;; A function is reduced to a prototype and keeps its `pub', so
+       ;; the importing unit declares it with external linkage
+       ((fn)
+        (cons (copy-form-source!
+               form
+               (take (strip-header-comments form 5) 5))
+              acc))
+       ;; A variable becomes an `extern' declaration
+       ((var)
+        (cons (copy-form-source!
+               form
+               (cons 'extern (take (cdr (strip-header-comments form 4)) 3)))
+              acc))
+       ((define defmacro enum import include struct typedef union)
+        (cons (copy-form-source! form (cdr form)) acc))
+       (else (sex-error form "pub must be followed by a definition" form))))
+    (else acc)))
 
 (define (load-persistent-module-paths)
   (let ((sex-module-path-env-var

tests/codegen.scm

@@ -230,33 +230,4 @@ compiles."
     (test-assert "grouping sublist still accepted"
       (emits? (in-fn "(var s (* (const struct suc)) 0)") "const struct suc * s"))
     (test-assert "flat chain still accepted"
-      (emits? (in-fn "(var q (* * const char) 0)") "const char * * q")))
-
-  ;; A string as the first body form (or after the name of a struct,
-  ;; union or enum) is a docstring: it becomes a comment immediately
-  ;; before the declaration, not a statement inside it.
-  (test-group "docstrings"
-    (test-assert "appears before the function"
-      (emits? "(fn greet ((name (* char))) void \"Greet NAME.\" (printf \"hi\" name))"
-              "/* Greet NAME. */"))
-    (test-assert "and not inside the body as a statement"
-      (not (emits? "(fn greet ((name (* char))) void \"Greet NAME.\" (printf \"hi\" name))"
-                   "\"Greet NAME.\"")))
-    (test-assert "multiline keeps its paragraphs"
-      (emits? "(pub fn main () int \"Entry point.\n\nARGC and ARGV.\" (return 0))"
-              "Entry point."))
-    (test-assert "and the second paragraph too"
-      (emits? "(pub fn main () int \"Entry point.\n\nARGC and ARGV.\" (return 0))"
-              "ARGC and ARGV."))
-    (test-assert "a prototype with only a docstring stays a prototype"
-      (emits? "(fn helper ((a int)) int \"Forward.\")"
-              "helper (int a);"))
-    (test-assert "a string after the first statement is left alone"
-      (emits? "(fn f () void (g) \"not a docstring\")"
-              "\"not a docstring\""))
-    (test-assert "a struct docstring sits above the struct"
-      (emits? "(struct point \"A 2D point.\" ((x int) (y int)))"
-              "/* A 2D point. */"))
-    (test-assert "and an enum docstring too"
-      (emits? "(enum color \"RGB.\" (red green blue))"
-              "/* RGB. */"))))
+      (emits? (in-fn "(var q (* * const char) 0)") "const char * * q"))))

tests/modules/greet.sex

@@ -13,9 +13,7 @@
                      ;; counted off by one
   int 0)
 
-(pub struct greeting
-  "A greeting to print."
-  ((text (* const char)) (times int)))
+(pub struct greeting ((text (* const char)) (times int)))
 
 (pub enum mood (cheerful grumpy))
 
@@ -31,7 +29,6 @@
 
 (pub fn greet ;; ...and here the prototype would lose its return type
   ((name (* const char))) void
-  "Print a greeting for NAME."
   (++ greet-count)
   (printf "hello, %s\n" name))
 

tests/semen.scm

@@ -1,35 +1,30 @@
 (import srfi-69
-        semen
-        types)
+        semen)
 
 (define print-str-fn
-  '(fn print-str ((s string)) void
+  '(fn void print-str ((string s))
        (printf "%s" s)))
 
 (define sum-fn
-  '(pub fn sum ((a int) (b int)) float
-        (return (cast (+ a b) float))))
+  '(pub fn float sum ((int a) (int b))
+        (return (cast float (+ a b)))))
 
 (test-group "semen"
   (test-assert (sex-fn? print-str-fn))
   (test #f (sex-fn-public? print-str-fn))
   (test 'void (sex-fn-return-type print-str-fn))
   (test 'print-str (sex-fn-name print-str-fn))
-  (test '((s string)) (sex-fn-arglist print-str-fn))
-  (test '(fn print-str ((s string)) void) (sex-fn-prototype print-str-fn))
+  (test '((string s)) (sex-fn-arglist print-str-fn))
+  (test '(fn void print-str ((string s))) (sex-fn-prototype print-str-fn))
   (test '((printf "%s" s)) (sex-fn-body print-str-fn))
 
   (test-assert (sex-fn? sum-fn))
   (test #t (sex-fn-public? sum-fn))
   (test 'float (sex-fn-return-type sum-fn))
   (test 'sum (sex-fn-name sum-fn))
-  (test '((a int) (b int)) (sex-fn-arglist sum-fn))
-  (test '(pub fn sum ((a int) (b int)) float) (sex-fn-prototype sum-fn))
-  (test '((return (cast (+ a b) float))) (sex-fn-body sum-fn))
-
-  (test-assert (sex-fn? '(extern fn foo () void)))
-  (test 'foo (sex-fn-name '(extern fn foo () void)))
-  (test #f (sex-fn? '(struct point ((x int)))))
+  (test '((int a) (int b)) (sex-fn-arglist sum-fn))
+  (test '(pub fn float sum ((int a) (int b))) (sex-fn-prototype sum-fn))
+  (test '((return (cast float (+ a b)))) (sex-fn-body sum-fn))
 
   (let ((sex-code
          '((defmacro (sum-var name a b c)
@@ -54,65 +49,9 @@
          '((defmacro (x10 a)
              `(* 10 ,a))
 
-           (fn foo ((a int) (b int)) void
+           (fn void foo ((int a) (int b))
                (return (+ a (x10 b)))))))
 
-    (test '((fn foo ((a int) (b int)) void
+    (test '((fn void foo ((int a) (int b))
                 (return (+ a (* 10 b)))))
-          (semen-process sex-code-macro)))
-
-;;; Docstrings are lifted out as comment forms sitting before the
-;;; declaration. A string later in a body is left alone.
-
-  (test '((comment "Greet NAME.")
-          (fn greet ((name (* char))) void
-              (printf "Hello %s!\n" name)))
-        (semen-process
-         '((fn greet ((name (* char))) void
-               "Greet NAME."
-               (printf "Hello %s!\n" name)))))
-
-  (test '((comment "Public entry.")
-          (pub fn main () int
-               (return 0)))
-        (semen-process
-         '((pub fn main () int
-                "Public entry."
-                (return 0)))))
-
-  ;; A prototype whose only "body" is a docstring stays a prototype
-  (test '((comment "Forward.")
-          (fn helper ((a int)) int))
-        (semen-process
-         '((fn helper ((a int)) int
-               "Forward."))))
-
-  (test '((fn f () void (g) "not a docstring"))
-        (semen-process
-         '((fn f () void (g) "not a docstring"))))
-
-  ;; `;' comments before the string are skipped when looking for it,
-  ;; and stay in the body
-  (test '((comment "Kept.")
-          (fn f () void (comment " note") (g)))
-        (semen-process
-         '((fn f () void (comment " note") "Kept." (g)))))
-
-  (test '((comment "A 2D point.")
-          (struct t-doc-pt ((x int) (y int))))
-        (semen-process
-         '((struct t-doc-pt "A 2D point." ((x int) (y int))))))
-
-  (test '((x int) (y int))
-        (get-fields 't-doc-pt))
-
-  (test '((comment "RGB.")
-          (enum t-doc-color (red green blue)))
-        (semen-process
-         '((enum t-doc-color "RGB." (red green blue)))))
-
-  (test '((comment "Either.")
-          (union t-doc-val ((i int) (f float))))
-        (semen-process
-         '((union t-doc-val "Either." ((i int) (f float))))))
-)
+          (semen-process sex-code-macro))))