Merge pull request #2722 from sgnr/disable-stdio-enable-backtraces

Make backtraces work again under DISABLE_STDIO

src/backtrace.c

@@ -4,7 +4,6 @@
 ** See Copyright Notice in mruby.h
 */
 
-#include <stdarg.h>
 #include "mruby.h"
 #include "mruby/variable.h"
 #include "mruby/proc.h"
@@ -13,119 +12,132 @@
 #include "mruby/class.h"
 #include "mruby/debug.h"
 #include "mruby/error.h"
+#include "mruby/numeric.h"
+
+struct backtrace_location {
+  int i;
+  int lineno;
+  const char *filename;
+  const char *method;
+  const char *sep;
+  const char *class_name;
+};
+
+typedef void (*output_stream_func)(mrb_state*, struct backtrace_location*, void*);
 
 #ifdef ENABLE_STDIO
 
-typedef void (*output_stream_func)(mrb_state*, void*, int, const char*, ...);
+struct print_backtrace_args {
+  FILE *stream;
+  int tracehead;
+};
 
 static void
-print_backtrace_i(mrb_state *mrb, void *stream, int level, const char *format, ...)
+print_backtrace_i(mrb_state *mrb, struct backtrace_location *loc, void *data)
 {
-  va_list ap;
+  struct print_backtrace_args *args;
 
-  va_start(ap, format);
-  vfprintf((FILE*)stream, format, ap);
-  va_end(ap);
-}
+  args = (struct print_backtrace_args*)data;
+
+  if (args->tracehead) {
+    fprintf(args->stream, "trace:\n");
+    args->tracehead = FALSE;
+  }
+
+  fprintf(args->stream, "\t[%d] %s:%d", loc->i, loc->filename, loc->lineno);
+
+  if (loc->method) {
+    if (loc->class_name) {
+      fprintf(args->stream, ":in %s%s%s", loc->class_name, loc->sep, loc->method);
+    }
+    else {
+      fprintf(args->stream, ":in %s", loc->method);
+    }
+  }
 
+  fprintf(args->stream, "\n");
+}
 
-#define MIN_BUFSIZE 127
+#endif
 
 static void
-get_backtrace_i(mrb_state *mrb, void *stream, int level, const char *format, ...)
+get_backtrace_i(mrb_state *mrb, struct backtrace_location *loc, void *data)
 {
-  va_list ap;
   mrb_value ary, str;
   int ai;
 
-  if (level > 0) {
-    return;
-  }
-
   ai = mrb_gc_arena_save(mrb);
-  ary = mrb_obj_value((struct RArray*)stream);
+  ary = mrb_obj_value((struct RArray*)data);
 
-  va_start(ap, format);
-  str = mrb_str_new(mrb, 0, vsnprintf(NULL, 0, format, ap) + 1);
-  va_end(ap);
+  str = mrb_str_new_cstr(mrb, loc->filename);
+  mrb_str_cat_lit(mrb, str, ":");
+  mrb_str_concat(mrb, str, mrb_fixnum_to_str(mrb, mrb_fixnum_value(loc->lineno), 10));
 
-  va_start(ap, format);
-  vsnprintf(RSTRING_PTR(str), RSTRING_LEN(str), format, ap);
-  va_end(ap);
+  if (loc->method) {
+    mrb_str_cat_lit(mrb, str, ":in ");
+
+    if (loc->class_name) {
+      mrb_str_cat_cstr(mrb, str, loc->class_name);
+      mrb_str_cat_cstr(mrb, str, loc->sep);
+    }
+
+    mrb_str_cat_cstr(mrb, str, loc->method);
+  }
 
-  mrb_str_resize(mrb, str, RSTRING_LEN(str) - 1);
   mrb_ary_push(mrb, ary, str);
   mrb_gc_arena_restore(mrb, ai);
 }
 
 static void
-output_backtrace(mrb_state *mrb, mrb_int ciidx, mrb_code *pc0, output_stream_func func, void *stream)
+output_backtrace(mrb_state *mrb, mrb_int ciidx, mrb_code *pc0, output_stream_func func, void *data)
 {
-  mrb_callinfo *ci;
-  const char *filename, *method, *sep;
-  int i, lineno, tracehead = 1;
+  int i;
 
   if (ciidx >= mrb->c->ciend - mrb->c->cibase)
     ciidx = 10; /* ciidx is broken... */
 
   for (i = ciidx; i >= 0; i--) {
+    struct backtrace_location loc;
+    mrb_callinfo *ci;
+    mrb_irep *irep;
+    mrb_code *pc;
+
     ci = &mrb->c->cibase[i];
-    filename = NULL;
 
     if (!ci->proc) continue;
-    if (MRB_PROC_CFUNC_P(ci->proc)) {
-      continue;
+    if (MRB_PROC_CFUNC_P(ci->proc)) continue;
+
+    irep = ci->proc->body.irep;
+
+    if (mrb->c->cibase[i].err) {
+      pc = mrb->c->cibase[i].err;
     }
-    else {
-      mrb_irep *irep = ci->proc->body.irep;
-      mrb_code *pc;
-
-      if (mrb->c->cibase[i].err) {
-        pc = mrb->c->cibase[i].err;
-      }
-      else if (i+1 <= ciidx) {
-        pc = mrb->c->cibase[i+1].pc - 1;
-      }
-      else {
-        pc = pc0;
-      }
-      filename = mrb_debug_get_filename(irep, (uint32_t)(pc - irep->iseq));
-      lineno = mrb_debug_get_line(irep, (uint32_t)(pc - irep->iseq));
+    else if (i+1 <= ciidx) {
+      pc = mrb->c->cibase[i+1].pc - 1;
     }
-    if (lineno == -1) continue;
-    if (ci->target_class == ci->proc->target_class)
-      sep = ".";
-    else
-      sep = "#";
-
-    if (!filename) {
-      filename = "(unknown)";
+    else {
+      pc = pc0;
     }
+    loc.filename = mrb_debug_get_filename(irep, (uint32_t)(pc - irep->iseq));
+    loc.lineno = mrb_debug_get_line(irep, (uint32_t)(pc - irep->iseq));
 
-    if (tracehead) {
-      func(mrb, stream, 1, "trace:\n");
-      tracehead = 0;
-    }
-    method = mrb_sym2name(mrb, ci->mid);
-    if (method) {
-      const char *cn = mrb_class_name(mrb, ci->proc->target_class);
-
-      if (cn) {
-        func(mrb, stream, 1, "\t[%d] ", i);
-        func(mrb, stream, 0, "%s:%d:in %s%s%s", filename, lineno, cn, sep, method);
-        func(mrb, stream, 1, "\n");
-      }
-      else {
-        func(mrb, stream, 1, "\t[%d] ", i);
-        func(mrb, stream, 0, "%s:%d:in %s", filename, lineno, method);
-        func(mrb, stream, 1, "\n");
-      }
+    if (loc.lineno == -1) continue;
+
+    if (ci->target_class == ci->proc->target_class) {
+      loc.sep = ".";
     }
     else {
-        func(mrb, stream, 1, "\t[%d] ", i);
-        func(mrb, stream, 0, "%s:%d", filename, lineno);
-        func(mrb, stream, 1, "\n");
+      loc.sep = "#";
+    }
+
+    if (!loc.filename) {
+      loc.filename = "(unknown)";
     }
+
+    loc.method = mrb_sym2name(mrb, ci->mid);
+    loc.class_name = mrb_class_name(mrb, ci->proc->target_class);
+    loc.i = i;
+    func(mrb, &loc, data);
   }
 }
 
@@ -134,7 +146,7 @@ exc_output_backtrace(mrb_state *mrb, struct RObject *exc, output_stream_func fun
 {
   mrb_value lastpc;
   mrb_code *code;
-  
+
   lastpc = mrb_obj_iv_get(mrb, exc, mrb_intern_lit(mrb, "lastpc"));
   if (mrb_nil_p(lastpc)) {
     code = NULL;
@@ -153,15 +165,31 @@ exc_output_backtrace(mrb_state *mrb, struct RObject *exc, output_stream_func fun
    overwritten.  So invoke these functions just after detecting exceptions.
 */
 
+#ifdef ENABLE_STDIO
+
 MRB_API void
 mrb_print_backtrace(mrb_state *mrb)
 {
+  struct print_backtrace_args args;
+
   if (!mrb->exc || mrb_obj_is_kind_of(mrb, mrb_obj_value(mrb->exc), E_SYSSTACK_ERROR)) {
     return;
   }
-  exc_output_backtrace(mrb, mrb->exc, print_backtrace_i, (void*)stderr);
+
+  args.stream = stderr;
+  args.tracehead = TRUE;
+  exc_output_backtrace(mrb, mrb->exc, print_backtrace_i, (void*)&args);
+}
+
+#else
+
+MRB_API void
+mrb_print_backtrace(mrb_state *mrb)
+{
 }
 
+#endif
+
 MRB_API mrb_value
 mrb_exc_backtrace(mrb_state *mrb, mrb_value self)
 {
@@ -187,24 +215,3 @@ mrb_get_backtrace(mrb_state *mrb)
 
   return ary;
 }
-
-#else
-
-MRB_API void
-mrb_print_backtrace(mrb_state *mrb)
-{
-}
-
-MRB_API mrb_value
-mrb_exc_backtrace(mrb_state *mrb, mrb_value self)
-{
-  return mrb_ary_new(mrb);
-}
-
-MRB_API mrb_value
-mrb_get_backtrace(mrb_state *mrb)
-{
-  return mrb_ary_new(mrb);
-}
-
-#endif