util: Convert util/u_printf.cpp to util/u_printf.c

By doing this to remove the need of C++ runtime when not using llvmpipe

Signed-off-by: Yonggang Luo <luoyonggang@gmail.com>
Reviewed-by: Mihai Preda <mhpreda@gmail.com>
Reviewed-by: Jason Ekstrand <jason.ekstrand@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15659>

src/util/u_printf.c

@@ -0,0 +1,96 @@
+//
+// Copyright 2020 Serge Martin
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the "Software"),
+// to deal in the Software without restriction, including without limitation
+// the rights to use, copy, modify, merge, publish, distribute, sublicense,
+// and/or sell copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+// OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+// OTHER DEALINGS IN THE SOFTWARE.
+//
+// Extract from Serge's printf clover code by airlied.
+
+#include <assert.h>
+#include <stdarg.h>
+#include <string.h>
+
+#include "macros.h"
+#include "u_printf.h"
+
+/* Some versions of MinGW are missing _vscprintf's declaration, although they
+ * still provide the symbol in the import library. */
+#ifdef __MINGW32__
+_CRTIMP int _vscprintf(const char *format, va_list argptr);
+#endif
+
+#ifndef va_copy
+#ifdef __va_copy
+#define va_copy(dest, src) __va_copy((dest), (src))
+#else
+#define va_copy(dest, src) (dest) = (src)
+#endif
+#endif
+
+size_t util_printf_next_spec_pos(const char *str, size_t pos)
+{
+   if (str == NULL)
+      return -1;
+
+   const char *str_found = str + pos;
+   do {
+      str_found = strchr(str_found, '%');
+      if (str_found == NULL)
+         return -1;
+
+      ++str_found;
+      if (*str_found == '%') {
+         ++str_found;
+         continue;
+      }
+
+      char *spec_pos = strpbrk(str_found, "cdieEfFgGaAosuxXp%");
+      if (spec_pos == NULL) {
+         return -1;
+      } else if (*spec_pos == '%') {
+         str_found = spec_pos;
+      } else {
+         return spec_pos - str;
+      }
+   } while (1);
+}
+
+size_t u_printf_length(const char *fmt, va_list untouched_args)
+{
+   int size;
+   char junk;
+
+   /* Make a copy of the va_list so the original caller can still use it */
+   va_list args;
+   va_copy(args, untouched_args);
+
+#ifdef _WIN32
+   /* We need to use _vcsprintf to calculate the size as vsnprintf returns -1
+    * if the number of characters to write is greater than count.
+    */
+   size = _vscprintf(fmt, args);
+   (void)junk;
+#else
+   size = vsnprintf(&junk, 1, fmt, args);
+#endif
+   assert(size >= 0);
+
+   va_end(args);
+
+   return size;
+}