+ Because of limitations of the stock Windows command shells, special
+ care is needed to pass some characters in the arguments of the
+ --cflags and --ldflags options. Backslashes should not be used in
+ file names passed to the compiler and linker via these options. Use
+ forward slashes instead. If the arguments to these two options
+ include the `=' character, like when passing a -DFOO=bar preprocessor
+ option, the argument with the `=' character should be enclosed in
+ quotes, like this:
+
+ configure --cflags "-DFOO=bar"
+
+ Support for options that include the `=' character require "command
+ extensions" to be enabled. (They are enabled by default, but your
+ system administrator could have changed that. See "cmd /?" for
+ details.) If command extensions are disabled, a warning message might
+ be displayed informing you that "using parameters that include the =
+ character by enclosing them in quotes will not be supported."
+
+ You may also use the --cflags and --ldflags options to pass
+ additional parameters to the compiler and linker, respectively; they
+ are frequently used to pass -I and -L flags to specify supplementary
+ include and library directories. If a directory name includes
+ spaces, you will need to enclose it in quotes, as follows
+ -I"C:/Program Files/GnuTLS-2.10.1/include". Note that only the
+ directory name is enclosed in quotes, not the entire argument. Also
+ note that this functionality is only supported if command extensions
+ are available. If command extensions are disabled and you attempt to
+ use this functionality you may see the following warning message
+ "Error in --cflags argument: ... Backslashes and quotes cannot be
+ used with --cflags. Please use forward slashes for filenames and
+ paths (e.g. when passing directories to -I)."
+