Avoid using `snprintf` when `MRB_DISABLE_STDIO` is set; fix #4173

1 files changed, 68 insertions, 22 deletions

diff --git a/mrbgems/mruby-compiler/core/parse.y b/mrbgems/mruby-compiler/core/parse.y
index 88d9ea4ee..f6c77859a 100644
--- a/mrbgems/mruby-compiler/core/parse.y
+++ b/mrbgems/mruby-compiler/core/parse.y
@@ -220,6 +220,25 @@ parser_strdup(parser_state *p, const char *s)
 #undef strdup
 #define strdup(s) parser_strdup(p, s)
 
+static void
+itoa(short i, char *s)
+{
+  char *p = s;
+  char *t = s;
+
+  while (i > 0) {
+    *p++ = (i % 10)+'0';
+    i /= 10;
+  }
+  if (p == s) *p++ = '0';
+  *p = 0;
+  p--;  /* point the last char */
+  while (t < p) {
+    char c = *t;
+    *t++ = *p;
+    *p-- = c;
+  }
+}
 /* xxx ----------------------------- */
 
 static node*
@@ -3172,7 +3191,7 @@ var_ref         : variable
                     {
                       char buf[16];
 
-                      snprintf(buf, sizeof(buf), "%d", p->lineno);
+                      itoa(p->lineno, buf);
                       $$ = new_int(p, buf, 10);
                     }
                 | keyword__ENCODING__
@@ -3692,11 +3711,12 @@ yyerror(parser_state *p, const char *s)
 }
 
 static void
-yyerror_i(parser_state *p, const char *fmt, int i)
+yyerror_c(parser_state *p, const char *msg, char c)
 {
   char buf[256];
 
-  snprintf(buf, sizeof(buf), fmt, i);
+  strcpy(buf, msg);
+  strcat(buf, &c);
   yyerror(p, buf);
 }
 
@@ -3735,11 +3755,13 @@ yywarning(parser_state *p, const char *s)
 }
 
 static void
-yywarning_s(parser_state *p, const char *fmt, const char *s)
+yywarning_s(parser_state *p, const char *msg, const char *s)
 {
   char buf[256];
 
-  snprintf(buf, sizeof(buf), fmt, s);
+  strcpy(buf, msg);
+  strcat(buf, ": ");
+  strcat(buf, s);
   yywarning(p, buf);
 }
 
@@ -3751,10 +3773,10 @@ backref_error(parser_state *p, node *n)
   c = intn(n->car);
 
   if (c == NODE_NTH_REF) {
-    yyerror_i(p, "can't set variable $%" MRB_PRId, intn(n->cdr));
+    yyerror_c(p, "can't set variable $", (char)intn(n->cdr)+'0');
   }
   else if (c == NODE_BACK_REF) {
-    yyerror_i(p, "can't set variable $%c", intn(n->cdr));
+    yyerror_c(p, "can't set variable $", (char)intn(n->cdr));
   }
   else {
     mrb_bug(p->mrb, "Internal error in backref_error() : n=>car == %S", mrb_fixnum_value(c));
@@ -4298,7 +4320,15 @@ parse_string(parser_state *p)
       }
       if (c < 0) {
         char buf[256];
-        snprintf(buf, sizeof(buf), "can't find heredoc delimiter \"%s\" anywhere before EOF", hinf->term);
+        const char s1[] = "can't find heredoc delimiter \"";
+        const char s2[] = "\" anywhere before EOF";
+
+        if (sizeof(s1)+sizeof(s2)+strlen(hinf->term)+1 >= sizeof(buf)) {
+          yyerror(p, "can't find heredoc delimiter anywhere before EOF");
+        }
+        strcpy(buf, s1);
+        strcat(buf, hinf->term);
+        strcat(buf, s2);
         yyerror(p, buf);
         return 0;
       }
@@ -4449,9 +4479,14 @@ parse_string(parser_state *p)
     pushback(p, re_opt);
     if (toklen(p)) {
       char msg[128];
+
+      strcpy(msg, "unknown regexp option");
       tokfix(p);
-      snprintf(msg, sizeof(msg), "unknown regexp option%s - %s",
-          toklen(p) > 1 ? "s" : "", tok(p));
+      if (toklen(p) > 1) {
+        strcat(msg, "s");
+      }
+      strcat(msg, " - ");
+      strcat(msg, tok(p));
       yyerror(p, msg);
     }
     if (f != 0) {
@@ -4879,7 +4914,10 @@ parser_yylex(parser_state *p)
         }
         if (c2) {
           char buf[256];
-          snprintf(buf, sizeof(buf), "invalid character syntax; use ?\\%c", c2);
+          char cc = (char)c2;
+
+          strcpy(buf, "invalid character syntax; use ?\\");
+          strcat(buf, &cc);
           yyerror(p, buf);
         }
       }
@@ -5252,7 +5290,7 @@ parser_yylex(parser_state *p)
     pushback(p, c);
     if (nondigit) {
       trailing_uc:
-      yyerror_i(p, "trailing '%c' in number", nondigit);
+      yyerror_c(p, "trailing non digit in number: ", (char)nondigit);
     }
     tokfix(p);
     if (is_float) {
@@ -5267,10 +5305,10 @@ parser_yylex(parser_state *p)
       errno = 0;
       d = mrb_float_read(tok(p), &endp);
       if (d == 0 && endp == tok(p)) {
-        yywarning_s(p, "corrupted float value %s", tok(p));
+        yywarning_s(p, "corrupted float value", tok(p));
       }
       else if (errno == ERANGE) {
-        yywarning_s(p, "float %s out of range", tok(p));
+        yywarning_s(p, "float out of range", tok(p));
         errno = 0;
       }
       pylval.nd = new_float(p, tok(p));
@@ -5612,7 +5650,7 @@ parser_yylex(parser_state *p)
       {
         unsigned long n = strtoul(tok(p), NULL, 10);
         if (n > INT_MAX) {
-          yyerror_i(p, "capture group index must be <= %d", INT_MAX);
+          yyerror(p, "capture group index must be <= " MRB_STRINGIZE(INT_MAX));
           return 0;
         }
         pylval.nd = new_nth_ref(p, (int)n);
@@ -5649,10 +5687,10 @@ parser_yylex(parser_state *p)
       }
       else if (ISDIGIT(c)) {
         if (p->tidx == 1) {
-          yyerror_i(p, "'@%c' is not allowed as an instance variable name", c);
+          yyerror_c(p, "wrong instance variable name: @", c);
         }
         else {
-          yyerror_i(p, "'@@%c' is not allowed as a class variable name", c);
+          yyerror_c(p, "wrong class variable name: @@", c);
         }
         return 0;
       }
@@ -5668,7 +5706,14 @@ parser_yylex(parser_state *p)
 
     default:
       if (!identchar(c)) {
-        yyerror_i(p,  "Invalid char '\\x%02X' in expression", c);
+        char buf[36];
+        const char s[] = "Invalid char in expression: 0x";
+
+        strcpy(buf, s);
+        buf[sizeof(s)]   = (c & 0xff00) >> 8;
+        buf[sizeof(s)+1] = (c & 0xff);
+        buf[sizeof(s)+2] = 0;
+        yyerror(p, buf);
         goto retry;
       }
 
@@ -6097,11 +6142,12 @@ mrb_load_exec(mrb_state *mrb, struct mrb_parser_state *p, mrbc_context *c)
     if (c) c->parser_nerr = p->nerr;
     if (p->capture_errors) {
       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->exc = mrb_obj_ptr(mrb_exc_new(mrb, E_SYNTAX_ERROR, buf, n));
+      strcpy(buf, "line ");
+      itoa(p->error_buffer[0].lineno, buf+5);
+      strcat(buf, ": ");
+      strcat(buf, p->error_buffer[0].message);
+      mrb->exc = mrb_obj_ptr(mrb_exc_new(mrb, E_SYNTAX_ERROR, buf, strlen(buf)));
       mrb_parser_free(p);
       return mrb_undef_value();
     }