0.9.4.77:

[sbcl.git] / doc / manual / ffi.texinfo

diff --git a/doc/manual/ffi.texinfo b/doc/manual/ffi.texinfo
index 5f365d9..ea13995 100644 (file)
--- a/doc/manual/ffi.texinfo
+++ b/doc/manual/ffi.texinfo
@@ -1,3 +1,7 @@
+@node  Foreign Function Interface
+@comment  node-name,  next,  previous,  up
+@chapter Foreign Function Interface
+
 This chapter describes SBCL's interface to C programs and
 libraries (and, since C interfaces are a sort of @emph{ingua
 franca} of the Unix world, to other programs and libraries in
@@ -20,7 +24,7 @@ notably in the name of the @code{SB-ALIEN} package.
 * Operations On Foreign Values::  
 * Foreign Variables::           
 * Foreign Data Structure Examples::  
-* Loading Unix Object Files::   
+* Loading Shared Object Files::  
 * Foreign Function Calls::      
 * Step-By-Step Example of the Foreign Function Interface::  
 @end menu
@@ -212,9 +216,9 @@ determine which field is active from context.
 @item
 The foreign type specifier @code{(sb-alien:enum @var{name} &rest
 @var{specs})} describes an enumeration type that maps between integer
-values and keywords. If @var{name} is @code{nil}, then the type is
+values and symbols. If @var{name} is @code{nil}, then the type is
 anonymous.  Each element of the @var{specs} list is either a Lisp
-keyword, or a list @code{(@var{keyword} @var{value})}.  @var{value} is
+symbol, or a list @code{(@var{symbol} @var{value})}.  @var{value} is
 an integer. If @var{value} is not supplied, then it defaults to one
 greater than the value for the preceding spec (or to zero if it is the
 first spec).
@@ -278,12 +282,14 @@ return zero values.
 
 @item
 The foreign type specifier @code{sb-alien:c-string} is similar to
-@code{(* char)}, but is interpreted as a null-terminated string, and
-is automatically converted into a Lisp string when accessed; or if the
+@code{(* char)}, but is interpreted as a null-terminated string, and is
+automatically converted into a Lisp string when accessed; or if the
 pointer is C @code{NULL} or @code{0}, then accessing it gives Lisp
-@code{nil}.  Lisp strings are stored with a trailing NUL
-termination, so no copying (either by the user or the implementation)
-is necessary when passing them to foreign code.
+@code{nil}.  Lisp strings of type @code{base-string} are stored with a
+trailing NUL termination, so no copying (either by the user or the
+implementation) is necessary when passing them to foreign code; strings
+of type @code{(simple-array character (*))} are copied by the
+implementation as required.
 
 Assigning a Lisp string to a @code{c-string} structure field or
 variable stores the contents of the string to the memory already
@@ -707,33 +713,14 @@ which can be manipulated in Lisp like this:
 (setq my-struct (slot my-struct 'n))
 @end lisp
 
-@node  Loading Unix Object Files
+@node  Loading Shared Object Files
 @comment  node-name,  next,  previous,  up
-@section Loading Unix Object Files
+@section Loading Shared Object Files
 
 Foreign object files can be loaded into the running Lisp process by
 calling @code{load-shared-object}.
 
-The @code{sb-alien:load-shared-object} loads a single object file into
-the currently running Lisp. The external symbols defining routines and
-variables are made available for future external references (e.g. by
-@code{extern-alien}). Forward references to foreign symbols aren't
-supported: @code{load-shared-object} must be run before any of the
-defined symbols are referenced.
-
-@quotation
-Note: As of SBCL 0.7.5, all foreign code (code loaded with
-@code{load-shared-object}) is lost when a Lisp
-core is saved with @code{sb-ext:save-lisp-and-die}, and no attempt is
-made to restore it when the core is loaded. Historically this has been
-an annoyance both for SBCL users and for CMUCL users.  It's hard to
-solve this problem completely cleanly, but some generally-reliable
-partial solution might be useful. Once someone in either camp gets
-sufficiently annoyed to create it, SBCL is likely to adopt some
-mechanism for automatically restoring foreign code when a saved core
-is loaded.
-@end quotation
-
+@include fun-sb-alien-load-shared-object.texinfo
 
 @node  Foreign Function Calls
 @comment  node-name,  next,  previous,  up
@@ -1134,7 +1121,7 @@ struct c_struct *c_function (i, s, r, a)
   printf("s = %s\n", s);
   printf("r->x = %d\n", r->x);
   printf("r->s = %s\n", r->s);
-  for (j = 0; j < 10; j++) printf("a[%d] = %d.\n", j, a[j]);
+  for (j = 0; j < 10; j++) printf("a[%d] = %d.\n", j, a[j]);
   r2 = (struct c_struct *) malloc (sizeof(struct c_struct));
   r2->x = i + 5;
   r2->s = "a C string";
@@ -1197,16 +1184,15 @@ routine, e.g.: @samp{cc -c test.c && ld -shared -o test.so test.o} (In
 order to enable incremental loading with some linkers, you may need to
 say @samp{cc -G 0 -c test.c})
 
-Once the C code has been compiled, you can start up Lisp and load it
-in: @samp{sbcl} Lisp should start up with its normal prompt.
+Once the C code has been compiled, you can start up Lisp and load it in:
+@samp{sbcl}.  Lisp should start up with its normal prompt.
 
 Within Lisp, compile the Lisp file. (This step can be done
 separately. You don't have to recompile every time.)
 @samp{(compile-file "test.lisp")}
 
 Within Lisp, load the foreign object file to define the necessary
-symbols: @samp{(load-shared-object "test.so")}.  This must be done
-before loading any code that refers to these symbols.
+symbols: @samp{(load-shared-object "test.so")}. 
 
 Now you can load the compiled Lisp (``fasl'') file into Lisp:
 @samp{(load "test.fasl")}