Add options to not include docstrings in binary.

This lets us build a smaller binary. The minimal tested
binary on x86-64 (with -Os, -s, and all options that shrink binary size
        turned on) is about 240 kB.

src/boot/boot.c

@@ -52,6 +52,16 @@ int main(int argc, const char **argv) {
         janet_array_push(args, janet_cstringv(argv[i]));
     janet_def(env, "process/args", janet_wrap_array(args), "Command line arguments.");
 
+    /* Add in options from janetconf.h so boot.janet can configure the image as needed. */
+    JanetTable *opts = janet_table(0);
+#ifdef JANET_NO_DOCSTRINGS
+    janet_table_put(opts, janet_ckeywordv("no-docstrings"), janet_wrap_true());
+#endif
+#ifdef JANET_NO_SOURCEMAPS
+    janet_table_put(opts, janet_ckeywordv("no-sourcemaps"), janet_wrap_true());
+#endif
+    janet_def(env, "process/config", janet_wrap_table(opts), "Boot options");
+
     /* Run bootstrap script to generate core image */
     status = janet_dobytes(env, janet_gen_boot, janet_gen_boot_size, "boot.janet", NULL);
 

src/boot/boot.janet

@@ -1843,7 +1843,29 @@ _fiber is bound to the suspended fiber
 ###
 
 (do
+
+  (defn proto-flatten
+    "Flatten a table and it's prototypes into a single table."
+    [into x]
+    (when x
+      (proto-flatten into (table/getproto x))
+      (loop [k :keys x]
+        (put into k (x k))))
+    into)
+
   (def env (fiber/getenv (fiber/current)))
+
+  # Modify env based on some options.
+  (loop [[k v] :pairs env
+         :when (symbol? k)]
+    (def flat (proto-flatten @{} v))
+    (when (process/config :no-docstrings)
+      (put flat :doc nil))
+    (when (process/config :no-sourcemaps)
+      (put flat :source-map nil))
+    (put env k flat))
+
+  (put env 'process/config nil)
   (def image (let [env-pairs (pairs (env-lookup env))
                    essential-pairs (filter (fn [[k v]] (or (cfunction? v) (abstract? v))) env-pairs)
                    lookup (table ;(mapcat identity essential-pairs))

src/include/janetconf.h

@@ -43,6 +43,8 @@
 /* #define JANET_NO_PEG */
 /* #define JANET_NO_TYPED_ARRAY */
 /* #define JANET_NO_INT_TYPES */
+/* #define JANET_NO_DOCSTRINGS */
+/* #define JANET_NO_SOURCEMAPS */
 /* #define JANET_REDUCED_OS */
 /* #define JANET_OUT_OF_MEMORY do { printf("janet out of memory\n"); exit(1); } while (0) */
 /* #define JANET_RECURSION_GUARD 1024 */

test/suite6.janet

@@ -157,5 +157,9 @@
 (assert (= (test-expand "./abc" ":cur:/:all:") "some-dir/abc") "module/expand-path 2")
 (assert (= (test-expand "abc/def.txt" ":cur:/:name:") "some-dir/def.txt") "module/expand-path 3")
 (assert (= (test-expand "abc/def.txt" ":cur:/:dir:/sub/:name:") "some-dir/abc/sub/def.txt") "module/expand-path 4")
+(assert (= (test-expand "/abc/../def.txt" ":all:") "/def.txt") "module/expand-path 5")
+(assert (= (test-expand "abc/../def.txt" ":all:") "def.txt") "module/expand-path 6")
+(assert (= (test-expand "../def.txt" ":all:") "../def.txt") "module/expand-path 7")
+(assert (= (test-expand "../././././abcd/../def.txt" ":all:") "../def.txt") "module/expand-path 8")
 
 (end-suite)