Add fcvt, ecvt, gcvt functions.

6 files changed, 78 insertions, 0 deletions

diff --git a/emcc b/emcc
index 8f71883d..a5b30b97 100755
--- a/emcc
+++ b/emcc
@@ -1285,6 +1285,11 @@ try:
           'wctob.c',
           'wctomb.c',
          ]],
+         ['stdlib', [
+           'ecvt.c',
+           'fcvt.c',
+           'gcvt.c',
+         ]],
          ['string', [
            'wcpcpy.c',
            'wcpncpy.c',
diff --git a/system/lib/libc/musl/src/stdlib/ecvt.c b/system/lib/libc/musl/src/stdlib/ecvt.c
new file mode 100644
index 00000000..79c3de63
--- /dev/null
+++ b/system/lib/libc/musl/src/stdlib/ecvt.c
@@ -0,0 +1,19 @@
+#include <stdlib.h>
+#include <stdio.h>
+
+char *ecvt(double x, int n, int *dp, int *sign)
+{
+	static char buf[16];
+	char tmp[32];
+	int i, j;
+
+	if (n-1U > 15) n = 15;
+	sprintf(tmp, "%.*e", n-1, x);
+	i = *sign = (tmp[0]=='-');
+	for (j=0; tmp[i]!='e'; j+=(tmp[i++]!='.'))
+		buf[j] = tmp[i];
+	buf[j] = 0;
+	*dp = atoi(tmp+i+1)+1;
+
+	return buf;
+}
diff --git a/system/lib/libc/musl/src/stdlib/fcvt.c b/system/lib/libc/musl/src/stdlib/fcvt.c
new file mode 100644
index 00000000..f90928fe
--- /dev/null
+++ b/system/lib/libc/musl/src/stdlib/fcvt.c
@@ -0,0 +1,25 @@
+#define _GNU_SOURCE
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+char *fcvt(double x, int n, int *dp, int *sign)
+{
+	char tmp[1500];
+	int i, lz;
+
+	if (n > 1400U) n = 1400;
+	sprintf(tmp, "%.*f", n, x);
+	i = (tmp[0] == '-');
+	if (tmp[i] == '0') lz = strspn(tmp+i+2, "0");
+	else lz = -(int)strcspn(tmp+i, ".");
+
+	if (n<=lz) {
+		*sign = i;
+		*dp = 1;
+		if (n>14U) n = 14;
+		return "000000000000000"+14-n;
+	}
+
+	return ecvt(x, n-lz, dp, sign);
+}
diff --git a/system/lib/libc/musl/src/stdlib/gcvt.c b/system/lib/libc/musl/src/stdlib/gcvt.c
new file mode 100644
index 00000000..6c075e25
--- /dev/null
+++ b/system/lib/libc/musl/src/stdlib/gcvt.c
@@ -0,0 +1,8 @@
+#include <stdlib.h>
+#include <stdio.h>
+
+char *gcvt(double x, int n, char *b)
+{
+	sprintf(b, "%.*g", n, x);
+	return b;
+}
diff --git a/system/lib/libcextra.symbols b/system/lib/libcextra.symbols
index 42e66b51..a365271d 100644
--- a/system/lib/libcextra.symbols
+++ b/system/lib/libcextra.symbols
@@ -1,4 +1,7 @@
          T btowc
+         T ecvt
+         T fcvt
+         T gcvt
          T iswalnum
          T iswalpha
          T iswblank
diff --git a/tests/runner.py b/tests/runner.py
index b866cc08..b2d586e7 100755
--- a/tests/runner.py
+++ b/tests/runner.py
@@ -1984,6 +1984,24 @@ Succeeded!
         self.do_run(src, "1.0 2.0 -1.0 -2.0 2.0 3.0 -2.0 -3.0 "
                          "1 2 -1 -2 2 2 -2 -2")
 
+    # This example borrowed from MSDN documentation
+    def test_fcvt(self):
+        src = '''
+          #include <stdlib.h>
+          #include <stdio.h>
+
+          int main() {
+             int  decimal, sign;
+             char *buffer;
+             double source = 3.1415926535;
+
+             buffer = fcvt(source, 7, &decimal, &sign);
+             printf("source: %2.10f   buffer: '%s'   decimal: %d   sign: %d\\n",
+                     source, buffer, decimal, sign);
+          }
+          '''
+        self.do_run(src, "source: 3.1415926535   buffer: '31415927'   decimal: 1   sign: 0");
+
     def test_llrint(self):
       if Settings.USE_TYPED_ARRAYS != 2: return self.skip('requires ta2')
       src = r'''