Address #137

Fix compiler bug when compiling desturctured bindings in a top-level
def or var. Also introduce janet_table_clone API call to make this
easier.

src/core/specials.c

@@ -116,7 +116,7 @@ static JanetSlot janetc_unquote(JanetFopts opts, int32_t argn, const Janet *argv
     return janetc_cslot(janet_wrap_nil());
 }
 
-/* Preform destructuring. Be careful to
+/* Perform destructuring. Be careful to
  * keep the order registers are freed.
  * Returns if the slot 'right' can be freed. */
 static int destructure(JanetCompiler *c,
@@ -282,12 +282,13 @@ static int varleaf(
     if (c->scope->flags & JANET_SCOPE_TOP) {
         /* Global var, generate var */
         JanetSlot refslot;
+        JanetTable *entry = janet_table_clone(reftab);
         JanetArray *ref = janet_array(1);
         janet_array_push(ref, janet_wrap_nil());
-        janet_table_put(reftab, janet_ckeywordv("ref"), janet_wrap_array(ref));
+        janet_table_put(entry, janet_ckeywordv("ref"), janet_wrap_array(ref));
-        janet_table_put(reftab, janet_ckeywordv("source-map"),
+        janet_table_put(entry, janet_ckeywordv("source-map"),
                         janet_wrap_tuple(janetc_make_sourcemap(c)));
-        janet_table_put(c->env, janet_wrap_symbol(sym), janet_wrap_table(reftab));
+        janet_table_put(c->env, janet_wrap_symbol(sym), janet_wrap_table(entry));
         refslot = janetc_cslot(janet_wrap_array(ref));
         janetc_emit_ssu(c, JOP_PUT_INDEX, refslot, s, 0, 0);
         return 1;
@@ -312,13 +313,14 @@ static int defleaf(
     JanetSlot s,
     JanetTable *tab) {
     if (c->scope->flags & JANET_SCOPE_TOP) {
-        janet_table_put(tab, janet_ckeywordv("source-map"),
+        JanetTable *entry = janet_table_clone(tab);
+        janet_table_put(entry, janet_ckeywordv("source-map"),
                         janet_wrap_tuple(janetc_make_sourcemap(c)));
         JanetSlot valsym = janetc_cslot(janet_ckeywordv("value"));
-        JanetSlot tabslot = janetc_cslot(janet_wrap_table(tab));
+        JanetSlot tabslot = janetc_cslot(janet_wrap_table(entry));
 
         /* Add env entry to env */
-        janet_table_put(c->env, janet_wrap_symbol(sym), janet_wrap_table(tab));
+        janet_table_put(c->env, janet_wrap_symbol(sym), janet_wrap_table(entry));
 
         /* Put value in table when evaulated */
         janetc_emit_sss(c, JOP_PUT, tabslot, valsym, s, 0);

src/core/table.c

@@ -208,6 +208,18 @@ const JanetKV *janet_table_to_struct(JanetTable *t) {
     return janet_struct_end(st);
 }
 
+/* Clone a table. */
+JanetTable *janet_table_clone(JanetTable *table) {
+    JanetTable *newTable = janet_gcalloc(JANET_MEMORY_TABLE, sizeof(JanetTable));
+    memcpy(newTable, table, sizeof(JanetTable));
+    newTable->data = malloc(newTable->capacity * sizeof(JanetKV));
+    if (NULL == newTable->data) {
+        JANET_OUT_OF_MEMORY;
+    }
+    memcpy(newTable->data, table->data, table->capacity * sizeof(JanetKV));
+    return newTable;
+}
+
 /* Merge a table or struct into a table */
 static void janet_table_mergekv(JanetTable *table, const JanetKV *kvs, int32_t cap) {
     int32_t i;

src/include/janet.h

@@ -1202,6 +1202,7 @@ JANET_API const JanetKV *janet_table_to_struct(JanetTable *t);
 JANET_API void janet_table_merge_table(JanetTable *table, JanetTable *other);
 JANET_API void janet_table_merge_struct(JanetTable *table, const JanetKV *other);
 JANET_API JanetKV *janet_table_find(JanetTable *t, Janet key);
+JANET_API JanetTable *janet_table_clone(JanetTable *table);
 
 /* Fiber */
 JANET_API JanetFiber *janet_fiber(JanetFunction *callee, int32_t capacity, int32_t argc, const Janet *argv);

test/suite0.janet

@@ -303,5 +303,16 @@
 # Regression Test
 (assert (= 1 (((compile '(fn [] 1) @{})))) "regression test")
 
+# Regression Test #137
+(def [a b c] (range 10))
+(assert (= a 0) "regression #137 (1)")
+(assert (= b 1) "regression #137 (2)")
+(assert (= c 2) "regression #137 (3)")
+
+(var [x y z] (range 10))
+(assert (= a 0) "regression #137 (4)")
+(assert (= b 1) "regression #137 (5)")
+(assert (= c 2) "regression #137 (6)")
+
 (end-suite)