better FFI error reporting

TODO.FACTOR.txt

@@ -1,6 +1,8 @@
 - live search: timer delay would be nice
 - help responder has no way to access { "foo" "bar" }
 - httpd search tools
+- condition rethrow restarts broken
+- menus broken (right click, left click another word)
 
 + ui:
 

library/compiler/alien/alien-invoke.factor

@@ -24,6 +24,10 @@ M: alien-invoke-error summary
 : alien-invoke ( ... return library function parameters -- ... )
     pick pick <alien-invoke-error> throw ;
 
+: ensure-dlsym ( node -- )
+    [ alien-invoke-dlsym dlsym drop ]
+    [ inference-warning ] recover ;
+
 \ alien-invoke [ string object string object ] [ ] <effect>
 "infer-effect" set-word-prop
 
@@ -33,7 +37,7 @@ M: alien-invoke-error summary
     pop-literal nip over set-alien-invoke-function
     pop-literal nip over set-alien-invoke-library
     pop-literal nip over set-alien-invoke-return
-    dup alien-invoke-dlsym dlsym drop
+    dup ensure-dlsym
     alien-invoke-stack
 ] "infer" set-word-prop
 

library/compiler/x86/architecture.factor

@@ -44,7 +44,7 @@ M: cs-loc v>operand cs-loc-n cs-reg reg-stack ;
     #! so this is mostly a no-op.
     swap slip stack-reg swap ADD ; inline
 
-: compile-c-call* ( symbol dll args -- operands )
+: compile-c-call* ( symbol dll args -- )
     dup length cells [
         <reversed> [ PUSH ] each %alien-invoke
     ] with-aligned-stack ;

library/tools/errors.factor

@@ -30,7 +30,9 @@ words definitions ;
     "Cannot convert to C string: " write third . ;
 
 : ffi-error. ( obj -- )
-    "FFI: " write third print ;
+    "FFI: " write
+    dup third [ write ": " write ] when*
+    fourth print ;
 
 : heap-scan-error. ( obj -- )
     "Cannot do next-object outside begin/end-scan" print drop ;

vm/os-unix.c

@@ -22,8 +22,8 @@ void ffi_dlopen(DLL *dll, bool error)
 	{
 		if(error)
 		{
-			general_error(ERROR_FFI,tag_object(
-				from_char_string(dlerror())),F,true);
+			general_error(ERROR_FFI,F,
+				tag_object(from_char_string(dlerror())),true);
 		}
 		else
 			dll->dll = NULL;
@@ -42,8 +42,8 @@ void *ffi_dlsym(DLL *dll, F_STRING *symbol, bool error)
 	{
 		if(error)
 		{
-			general_error(ERROR_FFI,tag_object(
-				from_char_string(dlerror())),F,true);
+			general_error(ERROR_FFI,tag_object(symbol),
+				tag_object(from_char_string(dlerror())),true);
 		}
 
 		return NULL;

vm/os-windows.c

@@ -58,7 +58,7 @@ void ffi_dlopen (DLL *dll, bool error)
 	{
 		dll->dll = NULL;
 		if(error)
-			general_error(ERROR_FFI, tag_object(get_error_message()),F,true);
+			general_error(ERROR_FFI, F, tag_object(get_error_message()),true);
 		else
 			return;
 	}
@@ -74,7 +74,8 @@ void *ffi_dlsym (DLL *dll, F_STRING *symbol, bool error)
 	if (!sym)
 	{
 		if(error)
-			general_error(ERROR_FFI, tag_object(get_error_message()),F,true);
+			general_error(ERROR_FFI, tag_object(symbol),
+				tag_object(get_error_message()),true);
 		else
 			return NULL;
 	}