declare and document scheme_set_dll_path() for Windows embedding

pkgs/racket-doc/scribblings/inside/embedding.scrbl

@@ -1,5 +1,6 @@
 #lang scribble/doc
-@(require "utils.rkt")
+@(require "utils.rkt"
+          scribble/bnf)
 
 @(define cgc-v-3m "CGC versus 3m")
 
@@ -114,16 +115,28 @@ To embed Racket CGC in a program, follow these steps:
   into the top-level environment.
 
   To embed a module like @racketmodname[racket/base] (along with all
-  its dependencies), use @exec{raco ctool --c-mods}, which generates a C file
+  its dependencies), use
+  @seclink["c-mods" #:doc raco-doc]{@exec{raco ctool --c-mods @nonterm{dest}}},
+  which generates a C file @nonterm{dest}
   that contains modules in bytecode form as encapsulated in a static
   array. The generated C file defines a @cppi{declare_modules}
   function that takes a @cpp{Scheme_Env*}, installs the modules into
   the environment, and adjusts the module name resolver to access the
-  embedded declarations.
+  embedded declarations. If embedded modules refer to runtime files
+  that need to be carried along, supply @DFlag{runtime} to
+  @exec{raco ctool --c-mods} to collect the runtime files into a
+  directory; see @secref[#:doc raco-doc "c-mods"] for more information.
 
-  Alternately, use @cpp{scheme_set_collects_path} and
+  Alternatively, use @cpp{scheme_set_collects_path} and
   @cpp{scheme_init_collection_paths} to configure and install a path
-  for finding modules at run time.}
+  for finding modules at run time.
+
+  On Windows, @exec{raco ctool --c-mods @nonterm{dest} --runtime
+  @nonterm{dest-dir}} includes in @nonterm{dest-dir} optional DLLs
+  that are referenced by the Racket library to support @tech[#:doc
+  reference-doc]{extflonums} and @racket[bytes-open-converter]. Call
+  @cpp{scheme_set_dll_path} to register @nonterm{dest-dir} so that
+  those DLLs can be found at run time.}
 
  @item{Access Racket through @cppi{scheme_dynamic_require},
   @cppi{scheme_load}, @cppi{scheme_eval}, and/or other functions

pkgs/racket-doc/scribblings/inside/hooks.scrbl

@@ -91,6 +91,15 @@ Like @cpp{scheme_init_collection_paths_post}, but with @racket[null]
 as the last argument.}
 
 
+@function[(void scheme_set_dll_path
+            [wchar_t* path])]{
+
+On Windows only, sets the path used to find optional DLLs that are used
+by the runtime system: @filepath{longdouble.dll} and one of @filepath{iconv.dll},
+@filepath{libiconv.dll}, or @filepath{libiconv-2.dll}. The given @var{path}
+should be an absolute path.}
+
+
 @function[(void scheme_seal_parameters)]{
 
 Takes a snapshot of the current values of built-in parameters. These

pkgs/racket-doc/scribblings/inside/utils.rkt

@@ -12,6 +12,7 @@
          function subfunction
          FormatD
          tech-place
+         reference-doc raco-doc
          (except-out (all-from-out scribble/manual) var)
          (for-label (all-from-out scheme/base)))
 
@@ -157,8 +158,11 @@
 
 (define mzc (exec "raco ctool"))
 
+(define reference-doc '(lib "scribblings/reference/reference.scrbl"))
+(define raco-doc '(lib "scribblings/raco/raco.scrbl"))
+
 (define (refsecref s)
-  (secref #:doc '(lib "scribblings/reference/reference.scrbl") s))
+  (secref #:doc reference-doc s))
 
 (define Racket
   (other-manual '(lib "scribblings/reference/reference.scrbl")))

racket/src/racket/cmdline.inc

@@ -106,8 +106,6 @@ static void (*console_printf)(char *str, ...);
 # define PRINTF console_printf
 #endif
 
-MZ_EXTERN void scheme_set_dll_path(wchar_t *s);
-
 static void record_dll_path(void)
 {
   if (_dlldir[_dlldir_offset] != '<') {

racket/src/racket/include/scheme.h

@@ -1946,6 +1946,9 @@ MZ_EXTERN void scheme_set_addon_dir(Scheme_Object *p);
 MZ_EXTERN void scheme_set_command_line_arguments(Scheme_Object *vec);
 MZ_EXTERN void scheme_set_compiled_file_paths(Scheme_Object *list);
 MZ_EXTERN void scheme_set_compiled_file_roots(Scheme_Object *list);
+#ifdef DOS_FILE_SYSTEM
+MZ_EXTERN void scheme_set_dll_path(wchar_t *s);
+#endif
 
 MZ_EXTERN void scheme_init_collection_paths(Scheme_Env *global_env, Scheme_Object *extra_dirs);
 MZ_EXTERN void scheme_init_collection_paths_post(Scheme_Env *global_env, Scheme_Object *extra_dirs, Scheme_Object *extra_post_dirs);