First draft of keyword arguments. mainly checking in in order to try working with git fusion on this branch.

Copied from Perforce
 Change: 181538
 ServerID: perforce.ravenbrook.com

13 files changed, 271 insertions, 22 deletions

diff --git a/mps/code/arena.c b/mps/code/arena.c
index 1273502968d..904ed0701ac 100644
--- a/mps/code/arena.c
+++ b/mps/code/arena.c
@@ -205,15 +205,16 @@ failGlobalsInit:
 }
 
 
-/* ArenaCreateV -- create the arena and call initializers */
+/* ArenaCreate -- create the arena and call initializers */
 
-Res ArenaCreateV(Arena *arenaReturn, ArenaClass class, va_list args)
+Res ArenaCreate(Arena *arenaReturn, ArenaClass class, ArgList args)
 {
   Arena arena;
   Res res;
 
   AVER(arenaReturn != NULL);
   AVERT(ArenaClass, class);
+  AVER(ArgListCheck(args));
 
   /* We must initialise the event subsystem very early, because event logging
      will start as soon as anything interesting happens and expect to write
diff --git a/mps/code/arenacl.c b/mps/code/arenacl.c
index d76a6d9a485..bfe640bfc05 100644
--- a/mps/code/arenacl.c
+++ b/mps/code/arenacl.c
@@ -186,8 +186,7 @@ static void ClientChunkFinish(Chunk chunk)
  * .arena.init: Once the arena has been allocated, we call ArenaInit
  * to do the generic part of init.
  */
-static Res ClientArenaInit(Arena *arenaReturn, ArenaClass class,
-                           va_list args)
+static Res ClientArenaInit(Arena *arenaReturn, ArenaClass class, ArgList args)
 {
   Arena arena;
   ClientArena clientArena;
@@ -196,11 +195,32 @@ static Res ClientArenaInit(Arena *arenaReturn, ArenaClass class,
   Addr base, limit, chunkBase;
   Res res;
   Chunk chunk;
- 
-  size = va_arg(args, Size);
-  base = va_arg(args, Addr);
+  mps_arg_s arg;
+  
   AVER(arenaReturn != NULL);
   AVER((ArenaClass)mps_arena_class_cl() == class);
+  AVER(ArgListCheck(args));
+
+  if (ArgPick(&arg, args, MPS_KEY_ARENA_SIZE)) {
+    size = arg.val.size;
+    if (ArgPick(&arg, args, MPS_KEY_ARENA_CL_ADDR))
+      base = arg.val.addr;
+    else {
+      res = ResPARAM;
+      goto failParam;
+    }
+  } else if (ArgPick(&arg, args, MPS_KEY_VARARGS)) {
+    if (ArgPick(&arg, args, MPS_KEY_ARENA_CL_ADDR)) {
+      res = ResPARAM;
+      goto failParam;
+    }
+    size = va_arg(arg.val.varargs, Size);
+    base = va_arg(arg.val.varargs, Addr);
+  } else {
+    res = ResPARAM;
+    goto failParam;
+  }
+
   AVER(base != (Addr)0);
 
   clArenaSize = SizeAlignUp(sizeof(ClientArenaStruct), MPS_PF_ALIGN);
@@ -243,6 +263,7 @@ static Res ClientArenaInit(Arena *arenaReturn, ArenaClass class,
 
 failChunkCreate:
   ArenaFinish(arena);
+failParam:
   return res;
 }
 
diff --git a/mps/code/arenacv.c b/mps/code/arenacv.c
index 5055cf421a6..7228ea80ee7 100644
--- a/mps/code/arenacv.c
+++ b/mps/code/arenacv.c
@@ -340,7 +340,7 @@ static void testPageTable(ArenaClass class, ...)
   va_list args;
 
   va_start(args, class);
-  die(ArenaCreateV(&arena, class, args), "ArenaCreate");
+  die(ArenaCreate(&arena, class, args), "ArenaCreate");
   va_end(args);
 
   die(PoolCreate(&pool, arena, PoolClassMV(),
diff --git a/mps/code/arenavm.c b/mps/code/arenavm.c
index ca2188c04b1..b0c2d732dc1 100644
--- a/mps/code/arenavm.c
+++ b/mps/code/arenavm.c
@@ -445,7 +445,7 @@ static void VMChunkFinish(Chunk chunk)
  * .arena.init: Once the arena has been allocated, we call ArenaInit
  * to do the generic part of init.
  */
-static Res VMArenaInit(Arena *arenaReturn, ArenaClass class, va_list args)
+static Res VMArenaInit(Arena *arenaReturn, ArenaClass class, ArgList args)
 {
   Size userSize;        /* size requested by user */
   Size chunkSize;       /* size actually created */
@@ -456,15 +456,26 @@ static Res VMArenaInit(Arena *arenaReturn, ArenaClass class, va_list args)
   Index gen;
   VM arenaVM;
   Chunk chunk;
-
-  userSize = va_arg(args, Size);
+  mps_arg_s arg;
+  
   AVER(arenaReturn != NULL);
   AVER(class == VMArenaClassGet() || class == VMNZArenaClassGet());
+  AVER(ArgListCheck(args));
+
+  if (ArgPick(&arg, args, MPS_KEY_ARENA_SIZE))
+    userSize = arg.val.size;
+  else if (ArgPick(&arg, args, MPS_KEY_VARARGS))
+    userSize = va_arg(arg.val.varargs, Size);
+  else {
+    res = ResPARAM;
+    goto failVMCreate;
+  }
+
   AVER(userSize > 0);
 
   /* Create a VM to hold the arena and map it. */
   vmArenaSize = SizeAlignUp(sizeof(VMArenaStruct), MPS_PF_ALIGN);
-  res = VMCreate(&arenaVM, vmArenaSize);
+  res = VMCreate(&arenaVM, vmArenaSize, args);
   if (res != ResOK)
     goto failVMCreate;
   res = VMMap(arenaVM, VMBase(arenaVM), VMLimit(arenaVM));
diff --git a/mps/code/arg.c b/mps/code/arg.c
new file mode 100644
index 00000000000..425bbf6c496
--- /dev/null
+++ b/mps/code/arg.c
@@ -0,0 +1,126 @@
+/* arg.c: ARGUMENT LISTS
+ *
+ * $Id: //info.ravenbrook.com/project/mps/custom/cet/main/code/bt.c#1 $
+ * Copyright (c) 2013 Ravenbrook Limited.  See end of file for license.
+ */
+
+#include "config.h"
+#include "check.h"
+#include "mpm.h"
+
+SRCID(arg, "$Id$");
+
+#define KeySig          ((Sig)0x519CE333) /* SIGnature KEYyy */
+typedef struct mps_key_s {
+  Sig sig;
+  const char *name;
+  Bool (*check)(Arg arg);
+} KeyStruct;
+
+
+static Bool ArgCheckCant(Arg arg) {
+  UNUSED(arg);
+  return TRUE;
+}
+
+const KeyStruct _mps_key_varargs = {KeySig, "VARARGS", ArgCheckCant};
+
+
+/* KeyCheck -- check the validity of an argument key */
+
+Bool KeyCheck(Key key)
+{
+  CHECKS(Key, key);
+  CHECKL(key->name != NULL);
+  CHECKL(FUNCHECK(key->check));
+  return TRUE;
+}
+
+
+Bool ArgCheck(Arg arg)
+{
+  CHECKL(arg != NULL);
+  CHECKD(Key, arg->key);
+  CHECKL(arg->key->check(arg));
+  return TRUE;
+}
+
+
+/* ArgCheck -- check the validity of an argument list */
+
+Bool ArgListCheck(ArgList args)
+{
+  Index i;
+  CHECKL(args != NULL);
+  /* FIXME: Maximum plausible length? */
+  for (i = 0; args[i].key != MPS_KEY_ARGS_END; ++i)
+    CHECKL(ArgCheck(&args[i]));
+  return TRUE;
+}
+
+
+Bool ArgPick(mps_arg_s *argOut, mps_arg_s args[], Key key) {
+  Index i;
+  
+  AVER(argOut != NULL);
+  AVERT(Arg, args);
+  AVERT(Key, key);
+
+  for (i = 0; args[i].key != MPS_KEY_ARGS_END; ++i)
+    if (args[i].key == key)
+      goto found;
+  return FALSE;
+
+found:
+  *argOut = args[i];
+  for(;;) {
+    args[i] = args[i + 1];
+    if (args[i].key == MPS_KEY_ARGS_END)
+      break;
+    ++i;
+  }
+
+  return TRUE;
+}
+
+
+/* C. COPYRIGHT AND LICENSE
+ *
+ * Copyright (C) 2001-2002 Ravenbrook Limited <http://www.ravenbrook.com/>.
+ * All rights reserved.  This is an open source license.  Contact
+ * Ravenbrook for commercial licensing options.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * 
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 
+ * 3. Redistributions in any form must be accompanied by information on how
+ * to obtain complete source code for this software and any accompanying
+ * software that uses this software.  The source code must either be
+ * included in the distribution or be available for no more than the cost
+ * of distribution plus a nominal fee, and must be freely redistributable
+ * under reasonable conditions.  For an executable file, complete source
+ * code means the source code for all modules it contains. It does not
+ * include source code for modules or files that typically accompany the
+ * major components of the operating system on which the executable file
+ * runs.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+ * PURPOSE, OR NON-INFRINGEMENT, ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDERS AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
diff --git a/mps/code/mpm.h b/mps/code/mpm.h
index 049cbf65343..98e35b54189 100644
--- a/mps/code/mpm.h
+++ b/mps/code/mpm.h
@@ -130,6 +130,14 @@ extern int (AddrComp)(Addr a, Addr b, Size size);
 extern Bool ResIsAllocFailure(Res res);
 
 
+/* Argument Lists */
+
+extern Bool KeyCheck(Key key);
+extern Bool ArgCheck(Arg arg);
+extern Bool ArgListCheck(ArgList args);
+extern Bool ArgPick(ArgStruct *argOut, ArgList args, Key key);
+
+
 /* Logs and Powers
  *
  * SizeIsP2 returns TRUE if and only if size is a non-negative integer
@@ -485,7 +493,7 @@ extern AbstractArenaClass AbstractArenaClassGet(void);
 extern Bool ArenaClassCheck(ArenaClass class);
 
 extern Bool ArenaCheck(Arena arena);
-extern Res ArenaCreateV(Arena *arenaReturn, ArenaClass class, va_list args);
+extern Res ArenaCreate(Arena *arenaReturn, ArenaClass class, mps_arg_s args[]);
 extern void ArenaDestroy(Arena arena);
 extern Res ArenaInit(Arena arena, ArenaClass class);
 extern void ArenaFinish(Arena arena);
@@ -966,7 +974,7 @@ extern Res RootsIterate(Globals arena, RootIterateFn f, void *p);
 
 extern Align VMAlign(VM vm);
 extern Bool VMCheck(VM vm);
-extern Res VMCreate(VM *VMReturn, Size size);
+extern Res VMCreate(VM *VMReturn, Size size, mps_arg_s args[]);
 extern void VMDestroy(VM vm);
 extern Addr VMBase(VM vm);
 extern Addr VMLimit(VM vm);
diff --git a/mps/code/mpmtypes.h b/mps/code/mpmtypes.h
index f7cf9a023ea..8df2e91dbb0 100644
--- a/mps/code/mpmtypes.h
+++ b/mps/code/mpmtypes.h
@@ -44,6 +44,11 @@ typedef void *Pointer;                  /* <design/type/#pointer> */
 typedef Word Clock;                     /* processor time */
 typedef MPS_T_ULONGEST ULongest;        /* <design/type/#ulongest> */
 
+typedef mps_arg_s ArgStruct;
+typedef mps_arg_s *Arg;
+typedef mps_arg_s *ArgList;
+typedef mps_key_t Key;
+
 typedef Word RefSet;                    /* design.mps.refset */
 typedef Word ZoneSet;                   /* design.mps.refset */
 typedef unsigned Rank;
@@ -109,7 +114,7 @@ typedef struct StackContextStruct *StackContext;
 /* Arena*Method -- see <code/mpmst.h#ArenaClassStruct> */
 
 typedef Res (*ArenaInitMethod)(Arena *arenaReturn,
-                               ArenaClass class, va_list args);
+                               ArenaClass class, mps_arg_s args[]);
 typedef void (*ArenaFinishMethod)(Arena arena);
 typedef Size (*ArenaReservedMethod)(Arena arena);
 typedef void (*ArenaSpareCommitExceededMethod)(Arena arena);
diff --git a/mps/code/mps.c b/mps/code/mps.c
index 1d1d93100d0..99cf42d5a33 100644
--- a/mps/code/mps.c
+++ b/mps/code/mps.c
@@ -70,6 +70,7 @@
 #include "ss.c"
 #include "version.c"
 #include "table.c"
+#include "arg.c"
 
 /* Additional pool classes */
 
diff --git a/mps/code/mps.h b/mps/code/mps.h
index 0c2cc9dbd53..0b450da9f5b 100644
--- a/mps/code/mps.h
+++ b/mps/code/mps.h
@@ -62,6 +62,7 @@ typedef struct mps_alloc_pattern_s
   *mps_alloc_pattern_t;                    /* allocation patterns */
 typedef struct mps_frame_s
   *mps_frame_t;                            /* allocation frames */
+typedef const struct mps_key_s *mps_key_t; /* argument key */
 
 /* Concrete Types */
 
@@ -91,6 +92,36 @@ enum {
   MPS_RES_PARAM                 /* illegal user parameter value */
 };
 
+/* Keyword argument lists */
+
+typedef struct mps_arg_s {
+  mps_key_t key;
+  union {
+    mps_bool_t b;
+    char c;
+    const char *string;
+    int i;
+    unsigned u;
+    long l;
+    unsigned long ul;
+    size_t size;
+    va_list varargs;
+    mps_addr_t addr;
+  } val;
+} mps_arg_s;
+
+#define MPS_KEY_ARGS_END        NULL
+
+/* FIXME: This shouldn't be here */
+extern const struct mps_key_s _mps_key_vmw3_top_down;
+#define MPS_KEY_VMW3_TOP_DOWN   (&_mps_key_vmw3_top_down)
+
+extern const struct mps_key_s _mps_key_varargs;
+#define MPS_KEY_VARARGS         (&_mps_key_varargs)
+extern const struct mps_key_s _mps_key_arena_size;
+#define MPS_KEY_ARENA_SIZE      (&_mps_key_arena_size)
+
+
 /* <a id="message.types"> Keep in sync with
  * <code/mpmtypes.h#message.types> */
 /* Not meant to be used by clients, they should use the macros below. */
@@ -272,6 +303,8 @@ extern mps_bool_t mps_arena_step(mps_arena_t, double, double);
 
 extern mps_res_t mps_arena_create(mps_arena_t *, mps_arena_class_t, ...);
 extern mps_res_t mps_arena_create_v(mps_arena_t *, mps_arena_class_t, va_list);
+extern mps_res_t mps_arena_create_args(mps_arena_t *, mps_arena_class_t,
+                                       mps_arg_s []);
 extern void mps_arena_destroy(mps_arena_t);
 
 extern size_t mps_arena_reserved(mps_arena_t);
diff --git a/mps/code/mps.xcodeproj/project.pbxproj b/mps/code/mps.xcodeproj/project.pbxproj
index 375124a990f..134e873becc 100644
--- a/mps/code/mps.xcodeproj/project.pbxproj
+++ b/mps/code/mps.xcodeproj/project.pbxproj
@@ -182,6 +182,7 @@
                 3124CAFB156BE82000753214 /* testlib.c in Sources */ = {isa = PBXBuildFile; fileRef = 31EEAC9E156AB73400714D05 /* testlib.c */; };
                 3124CAFC156BE82900753214 /* libmps.a in Frameworks */ = {isa = PBXBuildFile; fileRef = 31EEABFB156AAF9D00714D05 /* libmps.a */; };
                 3150AE53156ABA2500A6E22A /* libmps.a in Frameworks */ = {isa = PBXBuildFile; fileRef = 31EEABFB156AAF9D00714D05 /* libmps.a */; };
+                317B3C2B1731830100F9A469 /* arg.c in Sources */ = {isa = PBXBuildFile; fileRef = 317B3C2A1731830100F9A469 /* arg.c */; };
                 31A47BA4156C1E130039B1C2 /* mps.c in Sources */ = {isa = PBXBuildFile; fileRef = 31A47BA3156C1E130039B1C2 /* mps.c */; };
                 31D60007156D3C6200337B26 /* segsmss.c in Sources */ = {isa = PBXBuildFile; fileRef = 31D60006156D3C5F00337B26 /* segsmss.c */; };
                 31D60008156D3C7400337B26 /* libmps.a in Frameworks */ = {isa = PBXBuildFile; fileRef = 31EEABFB156AAF9D00714D05 /* libmps.a */; };
@@ -1049,6 +1050,7 @@
                 3124CAE4156BE6D500753214 /* fmthe.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = fmthe.c; sourceTree = "<group>"; };
                 3124CAEB156BE7F300753214 /* amcss */ = {isa = PBXFileReference; explicitFileType = "compiled.mach-o.executable"; includeInIndex = 0; path = amcss; sourceTree = BUILT_PRODUCTS_DIR; };
                 3124CAF5156BE81100753214 /* amcss.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = amcss.c; sourceTree = "<group>"; };
+                317B3C2A1731830100F9A469 /* arg.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = arg.c; sourceTree = "<group>"; };
                 31A47BA3156C1E130039B1C2 /* mps.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = mps.c; sourceTree = "<group>"; };
                 31A47BA5156C1E5E0039B1C2 /* ssixi3.c */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.c; path = ssixi3.c; sourceTree = "<group>"; };
                 31D60006156D3C5F00337B26 /* segsmss.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = segsmss.c; sourceTree = "<group>"; };
@@ -1568,6 +1570,7 @@
                                 31EEAC05156AB27B00714D05 /* arena.c */,
                                 31EEAC06156AB27B00714D05 /* arenacl.c */,
                                 31EEAC03156AB23A00714D05 /* arenavm.c */,
+                                317B3C2A1731830100F9A469 /* arg.c */,
                                 31EEAC3F156AB32500714D05 /* boot.c */,
                                 31EEAC27156AB2F200714D05 /* bt.c */,
                                 31EEAC19156AB2B200714D05 /* buffer.c */,
@@ -2690,6 +2693,7 @@
                         buildActionMask = 2147483647;
                         files = (
                                 31A47BA4156C1E130039B1C2 /* mps.c in Sources */,
+                                317B3C2B1731830100F9A469 /* arg.c in Sources */,
                         );
                         runOnlyForDeploymentPostprocessing = 0;
                 };
diff --git a/mps/code/mpsacl.h b/mps/code/mpsacl.h
index 62a8952ba83..ec7a21c027a 100644
--- a/mps/code/mpsacl.h
+++ b/mps/code/mpsacl.h
@@ -9,6 +9,9 @@
 
 #include "mps.h"
 
+/* Client arena base address argument */
+extern const struct mps_key_s _mps_key_arena_cl_addr;
+#define MPS_KEY_ARENA_CL_ADDR (&_mps_key_arena_cl_addr)
 
 extern mps_arena_class_t mps_arena_class_cl(void);
 
diff --git a/mps/code/mpsi.c b/mps/code/mpsi.c
index 435b4fbc0c6..15f44a24ff1 100644
--- a/mps/code/mpsi.c
+++ b/mps/code/mpsi.c
@@ -52,6 +52,10 @@
 #include "sac.h"
 #include "chain.h"
 
+#include <stdarg.h>
+#include <string.h>
+
+
 SRCID(mpsi, "$Id$");
 
 
@@ -311,11 +315,14 @@ mps_res_t mps_arena_create(mps_arena_t *mps_arena_o,
                            mps_arena_class_t mps_arena_class, ...)
 {
   mps_res_t res;
-  va_list args;
+  mps_arg_s args[2];
+
+  args[0].key = MPS_KEY_VARARGS;
+  va_start(args[0].val.varargs, mps_arena_class);
+  args[1].key = MPS_KEY_ARGS_END;
+  res = mps_arena_create_args(mps_arena_o, mps_arena_class, args);
+  va_end(args[0].val.varargs);
 
-  va_start(args, mps_arena_class);
-  res = mps_arena_create_v(mps_arena_o, mps_arena_class, args);
-  va_end(args);
   return res;
 }
 
@@ -323,7 +330,25 @@ mps_res_t mps_arena_create(mps_arena_t *mps_arena_o,
 /* mps_arena_create_v -- create an arena object */
 
 mps_res_t mps_arena_create_v(mps_arena_t *mps_arena_o,
-                             mps_arena_class_t arena_class, va_list args)
+                             mps_arena_class_t arena_class,
+                             va_list varargs)
+{
+  mps_arg_s args[2];
+  
+  args[0].key = MPS_KEY_VARARGS;
+  /* FIXME: va_copy not available in C89 */
+  memcpy(&args[0].val.varargs, &varargs, sizeof(va_list));
+  args[1].key = MPS_KEY_ARGS_END;
+
+  return mps_arena_create_args(mps_arena_o, arena_class, args);
+}
+
+
+/* mps_arena_create_arg -- create an arena object */
+
+mps_res_t mps_arena_create_args(mps_arena_t *mps_arena_o,
+                                mps_arena_class_t arena_class,
+                                mps_arg_s mps_args[])
 {
   Arena arena;
   Res res;
@@ -334,15 +359,21 @@ mps_res_t mps_arena_create_v(mps_arena_t *mps_arena_o,
 
   AVER(mps_arena_o != NULL);
 
-  res = ArenaCreateV(&arena, arena_class, args);
+  res = ArenaCreate(&arena, arena_class, mps_args);
   if (res != ResOK)
     return res;
 
+  /* FIXME: Consider doing this
+  if (args[0].key != MPS_KEY_ARGS_END)
+    return MPS_RES_PARAM;
+  */
+
   ArenaLeave(arena);
   *mps_arena_o = (mps_arena_t)arena;
   return MPS_RES_OK;
 }
 
+
 /* mps_arena_destroy -- destroy an arena object */
 
 void mps_arena_destroy(mps_arena_t arena)
diff --git a/mps/code/vmix.c b/mps/code/vmix.c
index bc26b647dc8..f5b8aa681b3 100644
--- a/mps/code/vmix.c
+++ b/mps/code/vmix.c
@@ -98,9 +98,12 @@ Bool VMCheck(VM vm)
 }
 
 
+Res VM
+
+
 /* VMCreate -- reserve some virtual address space, and create a VM structure */
 
-Res VMCreate(VM *vmReturn, Size size)
+Res VMCreate(VM *vmReturn, Size size, mps_arg_s args[])
 {
   Align align;
   VM vm;
@@ -109,6 +112,8 @@ Res VMCreate(VM *vmReturn, Size size)
   Res res;
 
   AVER(vmReturn != NULL);
+  AVERT(Arg, args);
+  UNUSED(args);
 
   /* Find out the page size from the OS */
   pagesize = getpagesize();