1 files changed, 14 insertions, 17 deletions

diff --git a/src/backtrace.c b/src/backtrace.c
index 57ae7fd7f..991a67d00 100644
--- a/src/backtrace.c
+++ b/src/backtrace.c
@@ -16,24 +16,24 @@
 #include <mruby/data.h>
 
 struct backtrace_location {
-  int lineno;
-  const char *filename;
+  int32_t lineno;
   mrb_sym method_id;
+  const char *filename;
 };
 
-typedef void (*each_backtrace_func)(mrb_state*, struct backtrace_location*, void*);
+typedef void (*each_backtrace_func)(mrb_state*, const struct backtrace_location*, void*);
 
 static const mrb_data_type bt_type = { "Backtrace", mrb_free };
 
 static void
 each_backtrace(mrb_state *mrb, ptrdiff_t ciidx, mrb_code *pc0, each_backtrace_func func, void *data)
 {
-  ptrdiff_t i, j;
+  ptrdiff_t i;
 
   if (ciidx >= mrb->c->ciend - mrb->c->cibase)
     ciidx = 10; /* ciidx is broken... */
 
-  for (i=ciidx, j=0; i >= 0; i--,j++) {
+  for (i=ciidx; i >= 0; i--) {
     struct backtrace_location loc;
     mrb_callinfo *ci;
     mrb_irep *irep;
@@ -57,11 +57,11 @@ each_backtrace(mrb_state *mrb, ptrdiff_t ciidx, mrb_code *pc0, each_backtrace_fu
     else {
       pc = pc0;
     }
-    loc.filename = mrb_debug_get_filename(irep, pc - irep->iseq);
-    loc.lineno = mrb_debug_get_line(irep, pc - irep->iseq);
 
+    loc.lineno = mrb_debug_get_line(mrb, irep, pc - irep->iseq);
     if (loc.lineno == -1) continue;
 
+    loc.filename = mrb_debug_get_filename(mrb, irep, pc - irep->iseq);
     if (!loc.filename) {
       loc.filename = "(unknown)";
     }
@@ -80,8 +80,6 @@ print_backtrace(mrb_state *mrb, mrb_value backtrace)
   mrb_int n;
   FILE *stream = stderr;
 
-  if (!mrb_array_p(backtrace)) return;
-
   n = RARRAY_LEN(backtrace) - 1;
   if (n == 0) return;
 
@@ -96,7 +94,7 @@ print_backtrace(mrb_state *mrb, mrb_value backtrace)
 }
 
 static int
-packed_bt_len(struct backtrace_location *bt, int n)
+packed_bt_len(const struct backtrace_location *bt, int n)
 {
   int len = 0;
   int i;
@@ -113,7 +111,7 @@ static void
 print_packed_backtrace(mrb_state *mrb, mrb_value packed)
 {
   FILE *stream = stderr;
-  struct backtrace_location *bt;
+  const struct backtrace_location *bt;
   int n, i;
   int ai = mrb_gc_arena_save(mrb);
 
@@ -124,7 +122,7 @@ print_packed_backtrace(mrb_state *mrb, mrb_value packed)
   if (packed_bt_len(bt, n) == 0) return;
   fprintf(stream, "trace (most recent call last):\n");
   for (i = 0; i<n; i++) {
-    struct backtrace_location *entry = &bt[n-i-1];
+    const struct backtrace_location *entry = &bt[n-i-1];
     if (entry->filename == NULL) continue;
     fprintf(stream, "\t[%d] %s:%d", i, entry->filename, entry->lineno);
     if (entry->method_id != 0) {
@@ -172,7 +170,7 @@ mrb_print_backtrace(mrb_state *mrb)
 
 static void
 count_backtrace_i(mrb_state *mrb,
-                 struct backtrace_location *loc,
+                 const struct backtrace_location *loc,
                  void *data)
 {
   int *lenp = (int*)data;
@@ -183,7 +181,7 @@ count_backtrace_i(mrb_state *mrb,
 
 static void
 pack_backtrace_i(mrb_state *mrb,
-                 struct backtrace_location *loc,
+                 const struct backtrace_location *loc,
                  void *data)
 {
   struct backtrace_location **pptr = (struct backtrace_location**)data;
@@ -206,7 +204,6 @@ packed_backtrace(mrb_state *mrb)
   each_backtrace(mrb, ciidx, mrb->c->ci->pc, count_backtrace_i, &len);
   size = len * sizeof(struct backtrace_location);
   ptr = mrb_malloc(mrb, size);
-  if (ptr) memset(ptr, 0, size);
   backtrace = mrb_data_object_alloc(mrb, NULL, ptr, &bt_type);
   backtrace->flags = (unsigned int)len;
   each_backtrace(mrb, ciidx, mrb->c->ci->pc, pack_backtrace_i, &ptr);
@@ -230,7 +227,7 @@ mrb_keep_backtrace(mrb_state *mrb, mrb_value exc)
 mrb_value
 mrb_unpack_backtrace(mrb_state *mrb, mrb_value backtrace)
 {
-  struct backtrace_location *bt;
+  const struct backtrace_location *bt;
   mrb_int n, i;
   int ai;
 
@@ -245,7 +242,7 @@ mrb_unpack_backtrace(mrb_state *mrb, mrb_value backtrace)
   backtrace = mrb_ary_new_capa(mrb, n);
   ai = mrb_gc_arena_save(mrb);
   for (i = 0; i < n; i++) {
-    struct backtrace_location *entry = &bt[i];
+    const struct backtrace_location *entry = &bt[i];
     mrb_value btline;
 
     if (entry->filename == NULL) continue;