Remove printf() linking hack

libc/stdio/vsnprintf.c

@@ -0,0 +1,64 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/dce.h"
+#include "libc/fmt/fmt.h"
+#include "libc/limits.h"
+#include "libc/macros.internal.h"
+#include "libc/runtime/runtime.h"
+#include "libc/str/str.h"
+
+struct SprintfStr {
+  char *p;
+  size_t i;
+  size_t n;
+};
+
+static int vsnprintfputchar(const char *s, struct SprintfStr *t, size_t n) {
+  if (n) {
+    if (n == 1 && t->i < t->n) {
+      t->p[t->i] = s[0];
+    } else if (t->i + n <= t->n) {
+      memcpy(t->p + t->i, s, n);
+    } else if (t->i < t->n) {
+      memcpy(t->p + t->i, s, t->n - t->i);
+    }
+    t->i += n;
+  }
+  return 0;
+}
+
+/**
+ * Formats string to buffer w/ preexisting vararg state.
+ *
+ * @param buf stores output and a NUL-terminator is always written,
+ *     provided buf!=NULL && size!=0
+ * @param size is byte capacity buf
+ * @return number of bytes written, excluding the NUL terminator; or,
+ *     if the output buffer wasn't passed, or was too short, then the
+ *     number of characters that *would* have been written is returned
+ * @see __fmt() and printf() for detailed documentation
+ * @asyncsignalsafe
+ * @vforksafe
+ */
+int(vsnprintf)(char *buf, size_t size, const char *fmt, va_list va) {
+  struct SprintfStr str = {buf, 0, size};
+  __fmt(vsnprintfputchar, &str, fmt, va);
+  if (str.n) str.p[MIN(str.i, str.n - 1)] = '\0';
+  return str.i;
+}