Add option to not compile the code generator.

This is useful when developing on machines where there is no working
backend.  (E.g., currently my old Mac and my netbook.)  To use this
put the following line into your mk/build.mk:

    DisableAsm = Yes

Makefile

@@ -23,6 +23,10 @@ ifneq ($(DebugLevel),)
 EXTRA_CFLAGS := $(EXTRA_CFLAGS) -DLC_DEBUG_LEVEL=$(DebugLevel)
 endif
 
+ifeq "$(strip $(DisableAsm))" "Yes"
+EXTRA_CFLAGS := $(EXTRA_CFLAGS) -DLC_HAS_ASM_BACKEND=0
+endif
+
 HSBUILDDIR = $(DIST)/build
 LCC = $(HSBUILDDIR)/lcc
 CABAL ?= cabal

includes/Config.h

@@ -3,7 +3,11 @@
 
 #ifndef LC_HAS_JIT
 # define LC_HAS_JIT      1
-#endif 
+#endif
+
+#ifndef LC_HAS_ASM_BACKEND
+# define LC_HAS_ASM_BACKEND 1
+#endif
 
 #undef NDEBUG
 #define DEBUG

mk/build.mk.sample

@@ -30,3 +30,11 @@
 # output.
 #
 # DebugLevel = 1
+
+# Lambdachine is currently x86-64 only.  You can still develop on 32
+# bit systems (e.g., a netbook, or ARM) if you turn off the code
+# generator.  You can test the trace compiler by using the IR
+# interpreter (it will of course be a lot slower).  Uncomment this
+# line to do just that.
+#
+# DisableAsm = Yes

rts/InterpThreaded.c

@@ -15,7 +15,9 @@
 #include "StorageManager.h"
 #include "Jit.h"
 #include "Stats.h"
+#if LC_HAS_ASM_BACKEND
 #include "InterpAsm.h"
+#endif
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -216,12 +218,16 @@ int engine(Capability *cap)
           Closure *cl;
           LC_ASSERT(F != NULL);
           recordEvent(EV_TRACE, 0);
+#if LC_HAS_ASM_BACKEND
           if(J->param[JIT_P_enableasm]) {
             asmEngine(cap, F);
           }
           else {
             irEngine(cap, F);
           }
+#else
+	  irEngine(cap, F);
+#endif
           DBG_PR("*** Continuing at: pc = %p, base = %p\n",
                  T->pc, T->base);
           //LC_ASSERT(0);
@@ -475,12 +481,16 @@ int engine(Capability *cap)
 
     LC_ASSERT(F != NULL);
     recordEvent(EV_TRACE, 0);
+#if LC_HAS_ASM_BACKEND
     if(J->param[JIT_P_enableasm]) {
       asmEngine(cap, F);
     }
     else {
       irEngine(cap, F);
     }
+#else
+      irEngine(cap, F);
+#endif
     DBG_PR("*** Continuing at: pc = %p, base = %p\n", T->pc, T->base);
 
     pc = T->pc;

rts/Record.c

@@ -14,7 +14,9 @@
 #include "Bitset.h"
 #include "Stats.h"
 #include "Opts.h"
+#if LC_HAS_ASM_BACKEND
 #include "AsmCodeGen.h"
+#endif
 
 #include <stdlib.h>
 #include <stdio.h>
@@ -961,12 +963,14 @@ finishRecording(JitState *J)
   DBG_PR("Overwriting startpc = %p, with: %x\n",
          J->startpc, *J->startpc);
 
+#if LC_HAS_ASM_BACKEND
   if(J->param[JIT_P_enableasm]) {
     //TODO: compute the actual framsize of a trace
     //This number needs to be computed before a call to genAsm
     J->cur.framesize = MAX_SLOTS;
     genAsm(J, &J->cur);
   }
+#endif
   return registerCurrentFragment(J);
 }
 

rts/Snapshot.c

@@ -9,8 +9,10 @@
 //
 #include "Snapshot.h"
 #include "PrintIR.h"
-#include "AsmTarget.h"
 #include "Thread.h"
+#if LC_HAS_ASM_BACKEND
+#include "AsmTarget.h"
+#endif
 
 #include <stdlib.h>
 #include <stdio.h>
@@ -154,6 +156,7 @@ printSnapshot(JitState *J, SnapShot *snap, SnapEntry *map)
   fprintf(stderr, "pc = %p\n", pc);
 }
 
+#if LC_HAS_ASM_BACKEND
 /* -- Snapshot restoration ------------------------------------------------ */
 /* Initialize a Bloom Filter with all renamed refs.
 ** There are very few renames (often none), so the filter has
@@ -249,7 +252,7 @@ void restoreSnapshot(SnapNo snapno, void *exptr) {
   T->base = base + smap[nent+1];
   T->top  = base + snap->nslots;
 }
-
+#endif	/* LC_HAS_ASM_BACKEND */
 
 #undef IR
 

rts/codegen/AsmCodeGen.c

@@ -3,6 +3,9 @@
 ** Copyright (C) 2005-2011 Mike Pall. See Copyright Notice in luajit.h
 */
 
+#include "Config.h"
+#if LC_HAS_ASM_BACKEND
+
 #include "AsmCodeGen.h"
 #include "AsmTarget.h" // Target Machine Definitions
 #include "Common.h"
@@ -1236,3 +1239,5 @@ void genAsm(JitState *J, Fragment *T) {
 }
 
 #undef IR
+
+#endif

rts/codegen/InterpAsm.c

@@ -1,3 +1,5 @@
+#include "Config.h"
+#if LC_HAS_ASM_BACKEND
 
 #include "Capability.h"
 #include "Jit.h"
@@ -222,3 +224,5 @@ asmExitIsImplementedInAssembly() {
     : : "i"(SAVE_SIZE + 256/* 256 bytes for int and float regs
                             * plus the extra space used by SAVE_SIZE */));
 }
+
+#endif

rts/codegen/MCode.c

@@ -3,6 +3,9 @@
 ** Copyright (C) 2005-2011 Mike Pall. See Copyright Notice in luajit.h
 */
 
+#include "Config.h"
+#if LC_HAS_ASM_BACKEND
+
 #include "Jit.h"
 #include "MCode.h"
 #include "InterpAsm.h" // for reference to asmExitHandler
@@ -231,3 +234,4 @@ void lj_mcode_limiterr(JitState *J, size_t need)
   traceError(J, 1);  /* Retry with new area. */
 }
 
+#endif