Inline fake snprintf to avoid linkage issues on Windows.

[chaoren]

Summary

dllexport doesn't work if linking against a static library with its own
copy of snprintf.

[zturner]

looks good, can you add a comment to explain why it's inlined though.

include/lldb/Host/windows/win32.h

 int chdir(const char* path);
 char* basename(char *path);
 char *dirname(char *path);
 
 int strcasecmp(const char* s1, const char* s2);
 int strncasecmp(const char* s1, const char* s2, size_t n);
 
 #if _MSC_VER < 1900
-int __declspec(dllexport)
-snprintf(char *buffer, size_t count, const char *format, ...);
+namespace lldb_private {
+int vsnprintf(char *buffer, size_t count, const char *format, va_list argptr);
+}
+
+int inline snprintf(char *buffer, size_t count, const char *format, ...)
+{
+    va_list argptr;
+    va_start(argptr, format);
+    int r = lldb_private::vsnprintf(buffer, count, format, argptr);
+    va_end(argptr);
+    return r;
+}
 #endif
 
 #define STDIN_FILENO  0
 #define STDOUT_FILENO 1
 #define STDERR_FILENO 2
 
 #define __PRETTY_FUNCTION__ __FUNCSIG__
 

source/Host/windows/Windows.cpp

 
 int usleep(uint32_t useconds)
 {
     Sleep(useconds / 1000);
     return 0;
 }
 
 #if _MSC_VER < 1900
-int snprintf(char *buffer, size_t count, const char *format, ...)
+namespace lldb_private {
+int vsnprintf(char *buffer, size_t count, const char *format, va_list argptr)
 {
     int old_errno = errno;
-    va_list argptr;
-    va_start(argptr, format);
-    int r = vsnprintf(buffer, count, format, argptr);
+    int r = ::vsnprintf(buffer, count, format, argptr);
     int new_errno = errno;
     buffer[count-1] = '\0';
     if (r == -1 || r == count)
     {
         FILE *nul = fopen("nul", "w");
-        int bytes_written = vfprintf(nul, format, argptr);
+        int bytes_written = ::vfprintf(nul, format, argptr);
         fclose(nul);
         if (bytes_written < count)
             errno = new_errno;
         else
         {
             errno = old_errno;
             r = bytes_written;
         }
     }
-    va_end(argptr);
     return r;
 }
+} // namespace lldb_private
 #endif
 
 #endif // _MSC_VER