Avoid use of `snprintf()` when DISABLE_STDIO is set; fix #3632

ref #3492 #3515 #3517

6 files changed, 55 insertions, 43 deletions

diff --git a/mrbgems/mruby-compiler/core/codegen.c b/mrbgems/mruby-compiler/core/codegen.c
index e790e6dfc..f863ef337 100644
--- a/mrbgems/mruby-compiler/core/codegen.c
+++ b/mrbgems/mruby-compiler/core/codegen.c
@@ -1024,9 +1024,9 @@ gen_assignment(codegen_scope *s, node *tree, int sp, int val)
 
   default:
 #ifndef MRB_DISABLE_STDIO
-    printf("unknown lhs %d\n", type);
+    fprintf(stderr, "unknown lhs %d\n", type);
 #endif
-    break;
+    return;
   }
   if (val) push();
 }
@@ -2195,11 +2195,11 @@ codegen(codegen_scope *s, node *tree, int val)
   case NODE_NTH_REF:
     if (val) {
       mrb_state *mrb = s->mrb;
-      char buf[32];
+      mrb_value str;
       int sym;
 
-      snprintf(buf, sizeof(buf), "$%" MRB_PRId, (mrb_int)(intptr_t)tree);
-      sym = new_sym(s, mrb_intern_cstr(mrb, buf));
+      str = mrb_format(mrb, "$%S", mrb_fixnum_value((mrb_int)(intptr_t)tree));
+      sym = new_sym(s, mrb_intern_str(mrb, str));
       genop(s, MKOP_ABx(OP_GETGLOBAL, cursp(), sym));
       push();
     }
diff --git a/mrbgems/mruby-eval/src/eval.c b/mrbgems/mruby-eval/src/eval.c
index 00cb2f15c..54a6aab2e 100644
--- a/mrbgems/mruby-eval/src/eval.c
+++ b/mrbgems/mruby-eval/src/eval.c
@@ -4,6 +4,7 @@
 #include <mruby/irep.h>
 #include <mruby/proc.h>
 #include <mruby/opcode.h>
+#include <mruby/error.h>
 
 mrb_value mrb_exec_irep(mrb_state *mrb, mrb_value self, struct RProc *p);
 mrb_value mrb_obj_instance_eval(mrb_state *mrb, mrb_value self);
@@ -175,12 +176,14 @@ create_proc_from_string(mrb_state *mrb, char *s, int len, mrb_value binding, con
 
   if (0 < p->nerr) {
     /* parse error */
-    char buf[256];
-    int n;
-    n = snprintf(buf, sizeof(buf), "line %d: %s\n", p->error_buffer[0].lineno, p->error_buffer[0].message);
+    mrb_value str;
+
+    str = mrb_format(mrb, "line %S: %S",
+                     mrb_fixnum_value(p->error_buffer[0].lineno),
+                     mrb_str_new_cstr(mrb, p->error_buffer[0].message));
     mrb_parser_free(p);
     mrbc_context_free(mrb, cxt);
-    mrb_exc_raise(mrb, mrb_exc_new(mrb, E_SYNTAX_ERROR, buf, n));
+    mrb_exc_raise(mrb, mrb_exc_new_str(mrb, E_SYNTAX_ERROR, str));
   }
 
   proc = mrb_generate_code(mrb, p);
diff --git a/mrbgems/mruby-proc-ext/src/proc.c b/mrbgems/mruby-proc-ext/src/proc.c
index f7f031e7b..b13606f5f 100644
--- a/mrbgems/mruby-proc-ext/src/proc.c
+++ b/mrbgems/mruby-proc-ext/src/proc.c
@@ -52,10 +52,7 @@ mrb_proc_inspect(mrb_state *mrb, mrb_value self)
 
     line = mrb_debug_get_line(irep, 0);
     if (line != -1) {
-      char buf[32];
-
-      snprintf(buf, sizeof(buf), "%" PRId32, line);
-      mrb_str_cat_cstr(mrb, str, buf);
+      str = mrb_format(mrb, "%S:%S", str, mrb_fixnum_value(line));
     }
     else {
       mrb_str_cat_lit(mrb, str, "-");
diff --git a/mrbgems/mruby-time/src/time.c b/mrbgems/mruby-time/src/time.c
index ce99a5a65..e367ddb64 100644
--- a/mrbgems/mruby-time/src/time.c
+++ b/mrbgems/mruby-time/src/time.c
@@ -5,12 +5,17 @@
 */
 
 #include <math.h>
-#include <stdio.h>
 #include <time.h>
 #include <mruby.h>
 #include <mruby/class.h>
 #include <mruby/data.h>
 
+#ifndef DISABLE_STDIO
+#include <stdio.h>
+#else
+#include <string.h>
+#endif
+
 #define NDIV(x,y) (-(-((x)+1)/(y))-1)
 
 #if _MSC_VER < 1800
@@ -55,6 +60,13 @@ double round(double x) {
 #endif
 #endif
 
+/* asctime(3) */
+/* mruby usually use its own implementation of struct tm to string conversion */
+/* except when DISABLE_STDIO is set. In that case, it uses asctime() or asctime_r(). */
+/* By default mruby tries to use asctime_r() which is reentrant. */
+/* Undef following macro on platforms that does not have asctime_r(). */
+/* #define NO_ASCTIME_R */
+
 /* timegm(3) */
 /* mktime() creates tm structure for localtime; timegm() is for UTC time */
 /* define following macro to use probably faster timegm() on the platform */
@@ -166,6 +178,7 @@ static const mrb_timezone_name timezone_names[] = {
   { "LOCAL", sizeof("LOCAL") - 1 },
 };
 
+#ifndef DISABLE_STDIO
 static const char mon_names[12][4] = {
   "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
 };
@@ -173,6 +186,7 @@ static const char mon_names[12][4] = {
 static const char wday_names[7][4] = {
   "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat",
 };
+#endif
 
 struct mrb_time {
   time_t              sec;
@@ -528,18 +542,28 @@ mrb_time_zone(mrb_state *mrb, mrb_value self)
 static mrb_value
 mrb_time_asctime(mrb_state *mrb, mrb_value self)
 {
-  struct mrb_time *tm;
-  struct tm *d;
-  char buf[256];
+  struct mrb_time *tm = time_get_ptr(mrb, self);
+  struct tm *d = &tm->datetime;
   int len;
 
-  tm = time_get_ptr(mrb, self);
-  d = &tm->datetime;
+#if defined(DISABLE_STDIO)
+  char *s;
+# ifdef NO_ASCTIME_R
+  s = asctime(d);
+# else
+  char buf[32];
+  s = asctime_r(d, buf);
+# endif
+  len = strlen(s)-1;            /* truncate the last newline */
+#else
+  char buf[256];
+
   len = snprintf(buf, sizeof(buf), "%s %s %02d %02d:%02d:%02d %s%d",
     wday_names[d->tm_wday], mon_names[d->tm_mon], d->tm_mday,
     d->tm_hour, d->tm_min, d->tm_sec,
     tm->timezone == MRB_TIMEZONE_UTC ? "UTC " : "",
     d->tm_year + 1900);
+#endif
   return mrb_str_new(mrb, buf, len);
 }
 
diff --git a/src/backtrace.c b/src/backtrace.c
index d634123b4..b60c375f3 100644
--- a/src/backtrace.c
+++ b/src/backtrace.c
@@ -74,14 +74,12 @@ static void
 get_backtrace_i(mrb_state *mrb, struct backtrace_location *loc, void *data)
 {
   mrb_value ary, str;
-  char buf[32];
   int ai = mrb_gc_arena_save(mrb);
 
   ary = mrb_obj_value((struct RArray*)data);
 
   str = mrb_str_new_cstr(mrb, loc->filename);
-  snprintf(buf, sizeof(buf), ":%d", loc->lineno);
-  mrb_str_cat_cstr(mrb, str, buf);
+  str = mrb_format(mrb, "%S:%S", str, mrb_fixnum_value(loc->lineno));
 
   if (loc->method) {
     mrb_str_cat_lit(mrb, str, ":in ");
@@ -400,14 +398,13 @@ mrb_restore_backtrace(mrb_state *mrb)
     int ai;
     mrb_backtrace_entry *entry;
     mrb_value mrb_entry;
-    char buf[32];
 
     ai = mrb_gc_arena_save(mrb);
     entry = &(mrb->backtrace.entries[i]);
 
-    mrb_entry = mrb_str_new_cstr(mrb, entry->filename);
-    snprintf(buf, sizeof(buf), ":%d", entry->lineno);
-    mrb_str_cat_cstr(mrb, mrb_entry, buf);
+    mrb_entry = mrb_format(mrb, "%S:%S",
+                           mrb_str_new_cstr(mrb, entry->filename),
+                           mrb_fixnum_value(entry->lineno));
     if (entry->method_id != 0) {
       mrb_str_cat_lit(mrb, mrb_entry, ":in ");
 
diff --git a/src/error.c b/src/error.c
index ac11e4d8d..258a8f7df 100644
--- a/src/error.c
+++ b/src/error.c
@@ -137,6 +137,7 @@ exc_inspect(mrb_state *mrb, mrb_value exc)
 {
   mrb_value str, mesg, file, line;
   mrb_bool append_mesg;
+  const char *cname;
 
   mesg = mrb_attr_get(mrb, exc, mrb_intern_lit(mrb, "mesg"));
   file = mrb_attr_get(mrb, exc, mrb_intern_lit(mrb, "file"));
@@ -148,28 +149,18 @@ exc_inspect(mrb_state *mrb, mrb_value exc)
     append_mesg = RSTRING_LEN(mesg) > 0;
   }
 
+  cname = mrb_obj_classname(mrb, exc);
+  str = mrb_str_new_cstr(mrb, cname);
   if (mrb_string_p(file) && mrb_fixnum_p(line)) {
-    char buf[32];
-
-    str = mrb_str_dup(mrb, file);
-    snprintf(buf, sizeof(buf), ":%" MRB_PRId ": ", mrb_fixnum(line));
-    mrb_str_cat_cstr(mrb, str, buf);
     if (append_mesg) {
-      mrb_str_cat_str(mrb, str, mesg);
-      mrb_str_cat_lit(mrb, str, " (");
+      str = mrb_format(mrb, "%S:%S:%S (%S)", file, line, mesg, str);
     }
-    mrb_str_cat_cstr(mrb, str, mrb_obj_classname(mrb, exc));
-    if (append_mesg) {
-      mrb_str_cat_lit(mrb, str, ")");
+    else {
+      str = mrb_format(mrb, "%S:%S:%S", file, line, str);
     }
   }
-  else {
-    const char *cname = mrb_obj_classname(mrb, exc);
-    str = mrb_str_new_cstr(mrb, cname);
-    if (append_mesg) {
-      mrb_str_cat_lit(mrb, str, ": ");
-      mrb_str_cat_str(mrb, str, mesg);
-    }
+  else if (append_mesg) {
+    str = mrb_format(mrb, "%S:%S", str, mesg);
   }
   return str;
 }