1 files changed, 221 insertions, 0 deletions
diff --git a/src/state.c b/src/state.c
new file mode 100644
index 0000000..da2f3c8
--- /dev/null
+++ b/src/state.c
@@ -0,0 +1,221 @@
+/*
+
+    casm - Simple, portable assembler
+
+    Copyright (C) 2003-2015  Ian Cowburn (ianc@noddybox.demon.co.uk)
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+    -------------------------------------------------------------------------
+
+    Stores assembly state.
+
+*/
+#include <stdlib.h>
+#include <string.h>
+
+#include "global.h"
+#include "state.h"
+#include "util.h"
+#include "expr.h"
+
+
+/* ---------------------------------------- GLOBALS
+*/
+static int      pass = 1;
+static int      maxpass = 2;
+static int      pc = 0;
+static int      size = 0x10000;
+static Byte     *mem = NULL;
+static int      minw = 0;
+static int      maxw = 0;
+static WordMode wmode = LSB_Word;
+
+
+/* ---------------------------------------- INTERFACES
+*/
+
+void ClearState(void)
+{
+    pass = 1;
+    pc = 0;
+    minw = size;
+    maxw = -1;
+    wmode = LSB_Word;
+    SetAddressSpace(0x10000);
+}
+
+
+void NextPass(void)
+{
+    if (pass < maxpass)
+    {
+        minw = size;
+        maxw = -1;
+        pass++;
+    }
+}
+
+
+int IsFinalPass(void)
+{
+    return pass == maxpass;
+}
+
+
+int IsFirstPass(void)
+{
+    return pass == 1;
+}
+
+
+int IsIntermediatePass(void)
+{
+    return pass > 1 && pass < maxpass;
+}
+
+
+int SetNeededPasses(int n)
+{
+    if (!IsFinalPass())
+    {
+        maxpass = n;
+    }
+}
+
+
+void SetAddressSpace(int s)
+{
+    size = s;
+
+    mem = Malloc(s);
+    memset(mem, 0, size);
+}
+
+
+void SetWordMode(WordMode mode)
+{
+    wmode = mode;
+}
+
+
+void SetPC(int i)
+{
+    pc = i;
+}
+
+
+int PC(void)
+{
+    return pc;
+}
+
+
+void PCAdd(int i)
+{
+    pc += i;
+
+    while(pc < 0)
+    {
+        pc += size;
+    }
+
+    pc %= size;
+}
+
+
+void PCWrite(int i)
+{
+    if (pc < minw)
+    {
+        minw = pc;
+    }
+
+    if (pc > maxw)
+    {
+        maxw = pc;
+    }
+
+    mem[pc] = ExprConvert(8, i);
+
+    pc = (pc + 1) % size;
+}
+
+
+void PCWriteWord(int i)
+{
+    PCWriteWordMode(i, wmode);
+}
+
+
+void PCWriteWordMode(int i, WordMode mode)
+{
+    int w;
+    int lsb;
+    int msb;
+
+    w = ExprConvert(16, i);
+
+    lsb = LOBYTE(w);
+    msb = HIBYTE(w);
+
+    switch(mode)
+    {
+        case MSB_Word:
+            PCWrite(msb);
+            PCWrite(lsb);
+            break;
+
+        case LSB_Word:
+            PCWrite(lsb);
+            PCWrite(msb);
+            break;
+    }
+}
+
+
+int GetMinAddressWritten(void)
+{
+    return minw;
+}
+
+
+int GetMaxAddressWritten(void)
+{
+    return maxw;
+}
+
+
+const Byte *AddressSpace(void)
+{
+    return mem;
+}
+
+
+Byte ReadByte(int addr)
+{
+    Byte b = 0;
+
+    if (addr > -1 && addr < size)
+    {
+        b = mem[addr];
+    }
+
+    return b;
+}
+
+
+/*
+vim: ai sw=4 ts=8 expandtab
+*/