* environ.cc (known): Add preload keyword.

* external.cc: Include new callout.h header.
(cygwin_internal): Initial implementation of CW_CALLOUT and CW_CYGHEAP_MALLOC.
(dll_preload): Handle CYGWIN=preload:foo.dll.
(dummy_callout): Default NULL callout function.
* globals.cc: Include new callout.h header.
(callout): Declare/define.
* uname.cc (uname): Initial implementation of callout handling.
* winsup.h (dll_preload): Declare.
* include/cygwin/version.h: Bump API minor number to 269.
* include/sys/cygwin.h: Define CW_CALLOUT, CW_CYGHEAP_MALLOC.

winsup/cygwin/ChangeLog

@@ -1,3 +1,18 @@
+2013-07-31  Christopher Faylor  <me.cygwin2013@cgf.cx>
+
+	* environ.cc (known): Add preload keyword.
+	* external.cc: Include new callout.h header.
+	(cygwin_internal): Initial implementation of CW_CALLOUT and
+	CW_CYGHEAP_MALLOC.
+	(dll_preload): Handle CYGWIN=preload:foo.dll.
+	(dummy_callout): Default NULL callout function.
+	* globals.cc: Include new callout.h header.
+	(callout): Declare/define.
+	* uname.cc (uname): Initial implementation of callout handling.
+	* winsup.h (dll_preload): Declare.
+	* include/cygwin/version.h: Bump API minor number to 269.
+	* include/sys/cygwin.h: Define CW_CALLOUT, CW_CYGHEAP_MALLOC.
+
 2013-07-31  Christopher Faylor  <me.cygwin2013@cgf.cx>
 
 	* cygheap.cc (cmalloc): Use size_t for size field.

winsup/cygwin/environ.cc

@@ -130,6 +130,7 @@ static struct parse_thing
   {"error_start", {func: error_start_init}, isfunc, NULL, {{0}, {0}}},
   {"export", {&export_settings}, setbool, NULL, {{false}, {true}}},
   {"glob", {func: glob_init}, isfunc, NULL, {{0}, {s: "normal"}}},
+  {"preload", {func: dll_preload}, isfunc,  NULL, {{0}, {0}}},
   {"pipe_byte", {&pipe_byte}, setbool, NULL, {{false}, {true}}},
   {"proc_retry", {func: set_proc_retry}, isfunc, NULL, {{0}, {5}}},
   {"reset_com", {&reset_com}, setbool, NULL, {{false}, {true}}},

winsup/cygwin/external.cc

@@ -30,6 +30,7 @@ details. */
 #include <stdlib.h>
 #include <wchar.h>
 #include <iptypes.h>
+#include <cygwin/callout.h>
 
 child_info *get_cygwin_startup_info ();
 static void exit_process (UINT, bool) __attribute__((noreturn));
@@ -553,9 +554,30 @@ cygwin_internal (cygwin_getinfo_types t, ...)
 	}
 	break;
 
+      case CW_CALLOUT:
+	callout = va_arg (arg, cw_callout_function_t);
+	break;
+
+      case CW_CYGHEAP_MALLOC:
+	res = (uintptr_t) cmalloc (HEAP_USER, va_arg (arg, size_t));
+	break;
+
       default:
 	set_errno (ENOSYS);
     }
   va_end (arg);
   return res;
 }
+
+extern "C" void
+dll_preload (const char *dll)
+{
+  if (!LoadLibrary (dll))
+    api_fatal ("couldn't load CYGWIN=preload DLL: %s, %E", dll);
+}
+
+extern "C" cw_callout_return_t
+dummy_callout (cw_callout_t, ...)
+{
+  return CO_R_KEEP_GOING;
+}

winsup/cygwin/globals.cc

@@ -17,6 +17,7 @@ details. */
 #include "thread.h"
 #include <malloc.h>
 #include <cygwin/version.h>
+#include <cygwin/callout.h>
 
 HANDLE NO_COPY hMainThread;
 HANDLE NO_COPY hProcToken;
@@ -75,6 +76,11 @@ bool reset_com;
 bool wincmdln;
 winsym_t allow_winsymlinks = WSYM_sysfile;
 
+extern "C" {
+cw_callout_return_t dummy_callout (cw_callout_t, ...);
+cw_callout_function_t callout = dummy_callout;
+};
+
 bool NO_COPY in_forkee;
 
 /* Taken from BSD libc:

winsup/cygwin/include/cygwin/callout.h

@@ -0,0 +1,30 @@
+/* callout.h -- Definitions used by Cygwin callout mechanism
+
+   Copyright 2013 Red Hat, Inc.
+
+This file is part of Cygwin.
+
+This software is a copyrighted work licensed under the terms of the
+Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
+details. */
+
+#pragma once
+
+extern "C" {
+enum cw_callout_t
+{
+  CO_ENV,
+  CO_SPAWN,
+  CO_SYMLINK,
+  CO_UNAME
+};
+
+enum cw_callout_return_t
+{
+  CO_R_ERROR,
+  CO_R_KEEP_GOING,
+  CO_R_SHORT_CIRCUIT
+};
+
+typedef cw_callout_return_t (*cw_callout_function_t) (cw_callout_t, ...);
+};

winsup/cygwin/include/cygwin/version.h

@@ -438,12 +438,13 @@ details. */
 	   arc4random_stir, arc4random_uniform.
       267: Export rawmemchr.
       268: Export GetCommandLineA, GetCommandLineW
+      269: Implement Cygwin callout functionality v1
      */
 
      /* Note that we forgot to bump the api for ualarm, strtoll, strtoull */
 
 #define CYGWIN_VERSION_API_MAJOR 0
-#define CYGWIN_VERSION_API_MINOR 268
+#define CYGWIN_VERSION_API_MINOR 269
 
      /* There is also a compatibity version number associated with the
 	shared memory regions.  It is incremented when incompatible

winsup/cygwin/include/sys/cygwin.h

@@ -143,7 +143,9 @@ typedef enum
     CW_CVT_ENV_TO_WINENV,
     CW_ALLOC_DRIVE_MAP,
     CW_MAP_DRIVE_MAP,
-    CW_FREE_DRIVE_MAP
+    CW_FREE_DRIVE_MAP,
+    CW_CALLOUT,
+    CW_CYGHEAP_MALLOC
   } cygwin_getinfo_types;
 
 #define CW_LOCK_PINFO CW_LOCK_PINFO
@@ -194,6 +196,8 @@ typedef enum
 #define CW_ALLOC_DRIVE_MAP CW_ALLOC_DRIVE_MAP
 #define CW_MAP_DRIVE_MAP CW_MAP_DRIVE_MAP
 #define CW_FREE_DRIVE_MAP CW_FREE_DRIVE_MAP
+#define CW_CALLOUT CW_CALLOUT
+#define CW_CYGHEAP_MALLOC CW_CYGHEAP_MALLOC
 
 /* Token type for CW_SET_EXTERNAL_TOKEN */
 enum

winsup/cygwin/uname.cc

@@ -15,6 +15,7 @@ details. */
 #include <sys/utsname.h>
 #include "cygwin_version.h"
 #include "cygtls.h"
+#include <cygwin/callout.h>
 
 /* uname: POSIX 4.4.1.1 */
 extern "C" int
@@ -91,5 +92,12 @@ uname (struct utsname *name)
 	break;
     }
 
+  switch (callout (CO_UNAME, name))
+    {
+    case CO_R_KEEP_GOING:
+      break;
+    default:
+      return -1;
+    }
   return 0;
 }

winsup/cygwin/winsup.h

@@ -198,6 +198,7 @@ void __stdcall close_all_files (bool = false);
 extern "C" void error_start_init (const char*);
 extern "C" int try_to_debug (bool waitloop = 1);
 
+extern "C" void dll_preload (const char*);
 void ld_preload ();
 const char *find_first_notloaded_dll (class path_conv &);