From 09a99f9af4e71dd6448665f6e165da81f8131efd Mon Sep 17 00:00:00 2001
From: "Michael D. Lowis" <mike@mdlowis.com>
Date: Fri, 9 May 2014 16:44:55 -0400
Subject: [PATCH] Started to add a return stack rather than using the C stack

---
 SConstruct                         | 14 +++++++-------
 source/slvm/extensions/core/core.c | 10 +++++-----
 source/slvm/kernel/pal.h           |  1 +
 source/slvm/kernel/slvm.h          |  4 ++--
 source/slvm/platforms/C99/pal.c    |  7 +++++--
 5 files changed, 20 insertions(+), 16 deletions(-)

diff --git a/SConstruct b/SConstruct
index c409734..e5c6d5d 100644
--- a/SConstruct
+++ b/SConstruct
@@ -121,11 +121,11 @@ c_cpp.StaticLibrary('build/lib/stdpf',
 # VM Executable Using Standard Platform
 c_cpp.Program('build/bin/slvm', [], LIBS = ['vmkernel', 'stdpf'])
 
-#nostdlib.Program('build/bin/slvm',
-#                 glob.glob('source/slvm/*.c'),
-#                 LIBPATH  = ['build/lib'],
-#                 LIBS     = ['gcc', 'stdpf'])
-
-# VM Extensions
-#c_cpp.SharedLibrary('build/lib/ioext', glob.glob('source/slvm/ext/io/*.c'))
+# Build all VM Extensions
+for ext in glob.glob('source/slvm/extensions/*/'):
+    name = os.path.basename(ext.strip('\\/'))
+    c_cpp.StaticLibrary('build/lib/'+name+'ext',
+                        glob.glob(ext + '/*.c'),
+                        CPPPATH = ['source/slvm/kernel'],
+                        LIBS = ['stdpf'])
 
diff --git a/source/slvm/extensions/core/core.c b/source/slvm/extensions/core/core.c
index b3d303b..ee202e9 100644
--- a/source/slvm/extensions/core/core.c
+++ b/source/slvm/extensions/core/core.c
@@ -2,8 +2,10 @@
 #include "pal.h"
 #include <stdlib.h>
 
-#if 0
-defcode("if", _if, 1, &bytemove){
+extern word_t zbranch, comma, here, swap, dup, wcode, nrot, rot, sub, wordsz,
+              mul, add, store, branch;
+
+defcode("if", _if, 1, NULL){
     /* Compile branch instruction */
     ArgStack++;
     *(ArgStack) = (val_t)&zbranch;
@@ -59,14 +61,12 @@ defcode("else", _else, 1, &_then){
     EXEC(_then);
     EXEC(swap);
 }
-#endif
 
 dict_t* core_init(dict_t* p_prev)
 {
     dict_t* p_dict = (dict_t*)pal_allocate(sizeof(dict_t));
     p_dict->name    = "core";
     p_dict->p_prev  = p_prev;
-    p_dict->p_words = (word_t*)NULL;
-    //p_dict->p_words = (word_t*)&_fpeekc;
+    p_dict->p_words = (word_t*)&_else;
     return p_dict;
 }
diff --git a/source/slvm/kernel/pal.h b/source/slvm/kernel/pal.h
index 634c2dc..8217d92 100644
--- a/source/slvm/kernel/pal.h
+++ b/source/slvm/kernel/pal.h
@@ -12,6 +12,7 @@
 #include <string.h>
 
 extern val_t* ArgStack;
+extern val_t* RetStack;
 extern val_t* CodePtr;
 
 dict_t* pal_init(dict_t* p_prev_dict);
diff --git a/source/slvm/kernel/slvm.h b/source/slvm/kernel/slvm.h
index dab6db1..421bf9b 100644
--- a/source/slvm/kernel/slvm.h
+++ b/source/slvm/kernel/slvm.h
@@ -91,8 +91,8 @@ typedef struct dict_t {
 #define EXEC(word) (word).codeword((word).code)
 
 /** The maximum number of entries that can be on the argument stack */
-#ifndef ARG_STACK_SIZE
-#define ARG_STACK_SIZE 32
+#ifndef STACK_SIZE
+#define STACK_SIZE 32
 #endif
 
 /**
diff --git a/source/slvm/platforms/C99/pal.c b/source/slvm/platforms/C99/pal.c
index b6f76d2..cf58660 100644
--- a/source/slvm/platforms/C99/pal.c
+++ b/source/slvm/platforms/C99/pal.c
@@ -8,9 +8,12 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-static val_t Stack[ARG_STACK_SIZE];
+static val_t AStack[STACK_SIZE];
+static val_t RStack[STACK_SIZE];
 static bool Line_Read = true;
-val_t* ArgStack = Stack - 1;
+
+val_t* ArgStack = AStack - 1;
+val_t* RetStack = RStack - 1;
 val_t* CodePtr = 0;
 
 defcode("allocate", mem_alloc, 1, NULL){
-- 
2.52.0