Merge pull request #4970 from dearblue/nostdio-sprintf

 Support `MRB_DISABLE_STDIO` for mruby-sprintf; ref #4954

include/mruby/numeric.h

@@ -37,6 +37,7 @@ MRB_API mrb_value mrb_fixnum_to_str(mrb_state *mrb, mrb_value x, mrb_int base);
 /* ArgumentError if format string doesn't match /%(\.[0-9]+)?[aAeEfFgG]/ */
 #ifndef MRB_WITHOUT_FLOAT
 MRB_API mrb_value mrb_float_to_str(mrb_state *mrb, mrb_value x, const char *fmt);
+MRB_API int mrb_float_to_cstr(mrb_state *mrb, char *buf, size_t len, const char *fmt, mrb_float f);
 MRB_API mrb_float mrb_to_flo(mrb_state *mrb, mrb_value x);
 MRB_API mrb_value mrb_int_value(mrb_state *mrb, mrb_float f);
 #endif

mrbgems/mruby-sprintf/src/sprintf.c

@@ -5,11 +5,6 @@
 */
 
 #include <mruby.h>
-
-#ifdef MRB_DISABLE_STDIO
-# error sprintf conflicts 'MRB_DISABLE_STDIO' configuration in your 'build_config.rb'
-#endif
-
 #include <limits.h>
 #include <string.h>
 #include <mruby/string.h>
@@ -521,6 +516,50 @@ mrb_f_sprintf(mrb_state *mrb, mrb_value obj)
   }
 }
 
+static int
+mrb_int2str(char *buf, size_t len, mrb_int n)
+{
+#ifdef MRB_DISABLE_STDIO
+  char *bufend = buf + len;
+  char *p = bufend - 1;
+
+  if (len < 1) return -1;
+
+  *p -- = '\0';
+  len --;
+
+  if (n < 0) {
+    if (len < 1) return -1;
+
+    *p -- = '-';
+    len --;
+    n = -n;
+  }
+
+  if (n > 0) {
+    for (; n > 0; len --, n /= 10) {
+      if (len < 1) return -1;
+
+      *p -- = '0' + (n % 10);
+    }
+    p ++;
+  }
+  else if (len > 0) {
+    *p = '0';
+    len --;
+  }
+  else {
+    return -1;
+  }
+
+  memmove(buf, p, bufend - p);
+
+  return bufend - p - 1;
+#else
+  return snprintf(buf, len, "%" MRB_PRId, n);
+#endif /* MRB_DISABLE_STDIO */
+}
+
 mrb_value
 mrb_str_format(mrb_state *mrb, mrb_int argc, const mrb_value *argv, mrb_value fmt)
 {
@@ -869,7 +908,7 @@ retry:
             width--;
           }
           mrb_assert(base == 10);
-          snprintf(nbuf, sizeof(nbuf), "%" MRB_PRId, v);
+          mrb_int2str(nbuf, sizeof(nbuf), v);
           s = nbuf;
           if (v < 0) s++;       /* skip minus sign */
         }
@@ -877,24 +916,12 @@ retry:
           s = nbuf;
           if (v < 0) {
             dots = 1;
+            val = mrb_fix2binstr(mrb, mrb_fixnum_value(v), base);
           }
-          switch (base) {
-          case 2:
-            if (v < 0) {
-              val = mrb_fix2binstr(mrb, mrb_fixnum_value(v), base);
-            }
-            else {
-              val = mrb_fixnum_to_str(mrb, mrb_fixnum_value(v), base);
-            }
-            strncpy(++s, RSTRING_PTR(val), sizeof(nbuf)-1);
-            break;
-          case 8:
-            snprintf(++s, sizeof(nbuf)-1, "%" MRB_PRIo, v);
-            break;
-          case 16:
-            snprintf(++s, sizeof(nbuf)-1, "%" MRB_PRIx, v);
-            break;
+          else {
+            val = mrb_fixnum_to_str(mrb, mrb_fixnum_value(v), base);
           }
+          strncpy(++s, RSTRING_PTR(val), sizeof(nbuf)-1);
           if (v < 0) {
             char d;
 
@@ -1071,7 +1098,7 @@ retry:
         need += 20;
 
         CHECK(need);
-        n = snprintf(&buf[blen], need, fbuf, fval);
+        n = mrb_float_to_cstr(mrb, &buf[blen], need, fbuf, fval);
         if (n < 0 || n >= need) {
           mrb_raise(mrb, E_RUNTIME_ERROR, "formatting error");
         }
@@ -1113,12 +1140,13 @@ fmt_setup(char *buf, size_t size, int c, int flags, mrb_int width, mrb_int prec)
   if (flags & FSPACE) *buf++ = ' ';
 
   if (flags & FWIDTH) {
-    n = snprintf(buf, end - buf, "%d", (int)width);
+    n = mrb_int2str(buf, end - buf, width);
     buf += n;
   }
 
   if (flags & FPREC) {
-    n = snprintf(buf, end - buf, ".%d", (int)prec);
+    *buf ++ = '.';
+    n = mrb_int2str(buf, end - buf, prec);
     buf += n;
   }
 

mrbgems/mruby-sprintf/test/sprintf.rb

@@ -8,6 +8,11 @@ assert('String#%') do
   assert_equal 15, ("%b" % (1<<14)).size
   skip unless Object.const_defined?(:Float)
   assert_equal "1.0", "%3.1f" % 1.01
+  assert_equal " 123456789.12", "% 4.2f" % 123456789.123456789
+  assert_equal "123456789.12", "%-4.2f" % 123456789.123456789
+  assert_equal "+123456789.12", "%+4.2f" % 123456789.123456789
+  assert_equal "123456789.12", "%04.2f" % 123456789.123456789
+  assert_equal "00000000123456789.12", "%020.2f" % 123456789.123456789
 end
 
 assert('String#% with inf') do

src/fmt_fp.c

@@ -37,9 +37,19 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #include <mruby.h>
 #include <mruby/string.h>
 
+struct fmt_args;
+
+typedef void output_func(struct fmt_args *f, const char *s, size_t l);
+
 struct fmt_args {
   mrb_state *mrb;
-  mrb_value str;
+  output_func *output;
+  void *opaque;
+};
+
+struct mrb_cstr {
+  char *buf;
+  size_t len;
 };
 
 #define MAX(a,b) ((a)>(b) ? (a) : (b))
@@ -54,15 +64,44 @@ struct fmt_args {
 #define PAD_POS    (1U<<(' '-' '))
 #define MARK_POS   (1U<<('+'-' '))
 
+#define FLAGMASK (ALT_FORM|ZERO_PAD|LEFT_ADJ|PAD_POS|MARK_POS)
+
+static output_func strcat_value;
+static output_func strcat_cstr;
+
+static void
+strcat_value(struct fmt_args *f, const char *s, size_t l)
+{
+  mrb_value str = *(mrb_value*)f->opaque;
+  mrb_str_cat(f->mrb, str, s, l);
+}
+
+static void
+strcat_cstr(struct fmt_args *f, const char *s, size_t l)
+{
+  struct mrb_cstr *cstr = (struct mrb_cstr*)f->opaque;
+
+  if (l > cstr->len) {
+    mrb_state *mrb = f->mrb;
+
+    mrb_raise(mrb, E_ARGUMENT_ERROR, "string buffer too small");
+  }
+
+  memcpy(cstr->buf, s, l);
+
+  cstr->buf += l;
+  cstr->len -= l;
+}
+
 static void
 out(struct fmt_args *f, const char *s, size_t l)
 {
-  mrb_str_cat(f->mrb, f->str, s, l);
+  f->output(f, s, l);
 }
 
 #define PAD_SIZE 256
 static void
-pad(struct fmt_args *f, char c, ptrdiff_t w, ptrdiff_t l, uint8_t fl)
+pad(struct fmt_args *f, char c, ptrdiff_t w, ptrdiff_t l, uint32_t fl)
 {
   char pad[PAD_SIZE];
   if (fl & (LEFT_ADJ | ZERO_PAD) || l >= w) return;
@@ -92,7 +131,7 @@ typedef char compiler_defines_long_double_incorrectly[9-(int)sizeof(long double)
 #endif
 
 static int
-fmt_fp(struct fmt_args *f, long double y, ptrdiff_t p, uint8_t fl, int t)
+fmt_fp(struct fmt_args *f, long double y, ptrdiff_t w, ptrdiff_t p, uint32_t fl, int t)
 {
   uint32_t big[(LDBL_MANT_DIG+28)/29 + 1          // mantissa expansion
     + (LDBL_MAX_EXP+LDBL_MANT_DIG+28+8)/9]; // exponent expansion
@@ -117,11 +156,11 @@ fmt_fp(struct fmt_args *f, long double y, ptrdiff_t p, uint8_t fl, int t)
   if (!isfinite(y)) {
     const char *ss = (t&32)?"inf":"INF";
     if (y!=y) ss=(t&32)?"nan":"NAN";
-    pad(f, ' ', 0, 3+pl, fl&~ZERO_PAD);
+    pad(f, ' ', w, 3+pl, fl&~ZERO_PAD);
     out(f, prefix, pl);
     out(f, ss, 3);
-    pad(f, ' ', 0, 3+pl, fl^LEFT_ADJ);
-    return 3+(int)pl;
+    pad(f, ' ', w, 3+pl, fl^LEFT_ADJ);
+    return MAX(w, 3+(int)pl);
   }
 
   y = frexp((double)y, &e2) * 2;
@@ -169,14 +208,14 @@ fmt_fp(struct fmt_args *f, long double y, ptrdiff_t p, uint8_t fl, int t)
     else
       l = (s-buf) + (ebuf-estr);
 
-    pad(f, ' ', 0, pl+l, fl);
+    pad(f, ' ', w, pl+l, fl);
     out(f, prefix, pl);
-    pad(f, '0', 0, pl+l, fl^ZERO_PAD);
+    pad(f, '0', w, pl+l, fl^ZERO_PAD);
     out(f, buf, s-buf);
     pad(f, '0', l-(ebuf-estr)-(s-buf), 0, 0);
     out(f, estr, ebuf-estr);
-    pad(f, ' ', 0, pl+l, fl^LEFT_ADJ);
-    return (int)pl+(int)l;
+    pad(f, ' ', w, pl+l, fl^LEFT_ADJ);
+    return MAX(w, (int)pl+(int)l);
   }
   if (p<0) p=6;
 
@@ -288,9 +327,9 @@ fmt_fp(struct fmt_args *f, long double y, ptrdiff_t p, uint8_t fl, int t)
     l += ebuf-estr;
   }
 
-  pad(f, ' ', 0, pl+l, fl);
+  pad(f, ' ', w, pl+l, fl);
   out(f, prefix, pl);
-  pad(f, '0', 0, pl+l, fl^ZERO_PAD);
+  pad(f, '0', w, pl+l, fl^ZERO_PAD);
 
   if ((t|32)=='f') {
     if (a>r) a=r;
@@ -325,21 +364,33 @@ fmt_fp(struct fmt_args *f, long double y, ptrdiff_t p, uint8_t fl, int t)
     out(f, estr, ebuf-estr);
   }
 
-  pad(f, ' ', 0, pl+l, fl^LEFT_ADJ);
+  pad(f, ' ', w, pl+l, fl^LEFT_ADJ);
 
-  return (int)pl+(int)l;
+  return MAX(w, (int)pl+(int)l);
 }
 
 static int
 fmt_core(struct fmt_args *f, const char *fmt, mrb_float flo)
 {
-  ptrdiff_t p;
+  ptrdiff_t w, p;
+  uint32_t fl;
 
   if (*fmt != '%') {
     return -1;
   }
   ++fmt;
 
+  /* Read modifier flags */
+  for (fl=0; (unsigned)*fmt-' '<32 && (FLAGMASK&(1U<<(*fmt-' '))); fmt++)
+    fl |= 1U<<(*fmt-' ');
+
+  /* - and 0 flags are mutually exclusive */
+  if (fl & LEFT_ADJ) fl &= ~ZERO_PAD;
+
+  for (w = 0; ISDIGIT(*fmt); ++fmt) {
+    w = 10 * w + (*fmt - '0');
+  }
+
   if (*fmt == '.') {
     ++fmt;
     for (p = 0; ISDIGIT(*fmt); ++fmt) {
@@ -353,29 +404,49 @@ fmt_core(struct fmt_args *f, const char *fmt, mrb_float flo)
   switch (*fmt) {
   case 'e': case 'f': case 'g': case 'a':
   case 'E': case 'F': case 'G': case 'A':
-    return fmt_fp(f, flo, p, 0, *fmt);
+    return fmt_fp(f, flo, w, p, fl, *fmt);
   default:
     return -1;
   }
 }
 
-mrb_value
+MRB_API mrb_value
 mrb_float_to_str(mrb_state *mrb, mrb_value flo, const char *fmt)
 {
   struct fmt_args f;
+  mrb_value str = mrb_str_new_capa(mrb, 24);
 
   f.mrb = mrb;
-  f.str = mrb_str_new_capa(mrb, 24);
+  f.output = strcat_value;
+  f.opaque = (void*)&str;
   if (fmt_core(&f, fmt, mrb_float(flo)) < 0) {
     mrb_raise(mrb, E_ARGUMENT_ERROR, "invalid format string");
   }
-  return f.str;
+  return str;
+}
+
+MRB_API int
+mrb_float_to_cstr(mrb_state *mrb, char *buf, size_t len, const char *fmt, mrb_float fval)
+{
+  struct fmt_args f;
+  struct mrb_cstr cstr;
+
+  cstr.buf = buf;
+  cstr.len = len - 1; /* reserve NUL terminator */
+  f.mrb = mrb;
+  f.output = strcat_cstr;
+  f.opaque = (void*)&cstr;
+  if (fmt_core(&f, fmt, fval) < 0) {
+    mrb_raise(mrb, E_ARGUMENT_ERROR, "invalid format string");
+  }
+  *cstr.buf = '\0';
+  return cstr.buf - buf;
 }
 #else   /* MRB_DISABLE_STDIO || _WIN32 || _WIN64 */
 #include <mruby.h>
 #include <stdio.h>
 
-mrb_value
+MRB_API mrb_value
 mrb_float_to_str(mrb_state *mrb, mrb_value flo, const char *fmt)
 {
   char buf[25];
@@ -383,5 +454,11 @@ mrb_float_to_str(mrb_state *mrb, mrb_value flo, const char *fmt)
   snprintf(buf, sizeof(buf), fmt, mrb_float(flo));
   return mrb_str_new_cstr(mrb, buf);
 }
+
+MRB_API int
+mrb_float_to_cstr(mrb_state *mrb, char *buf, size_t len, const char *fmt, mrb_float fval)
+{
+  return snprintf(buf, len, fmt, fval);
+}
 #endif  /* MRB_DISABLE_STDIO || _WIN32 || _WIN64 */
 #endif