commit 261a2458d2047696e1309260e57edf5f4a2b7b17
parent 8edef0087c2720964f76c07576781811529b5eeb
Author: Brian Swetland <swetland@frotz.net>
Date: Sat, 7 Apr 2012 16:15:15 -0700
a16: a number of shiny new features
- accept WORD, DAT, DATA, and DW for immediate data
- allow label: as well as :label to specify a label
- allow "quoted strings" in immediate data
- allow multiple (comma separated) values in a DATA statement
- allow [reg, imm] and [reg + imm] operand style
- don't try to disassemble constant data
- accept JMP b as an alias for SET PC, b
- accept MOV a, b as an alias for SET a, b
- prefer JMP and MOV in disassembly
- prefer [reg, imm] in disassembly
- TODO: option to request "classic" syntax in disassembly
Diffstat:
| M | assembler.c | | | 109 | ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--------------- |
| M | disassemble.c | | | 9 | +++++++-- |
2 files changed, 96 insertions(+), 22 deletions(-)
diff --git a/assembler.c b/assembler.c
@@ -39,12 +39,14 @@
#include <ctype.h>
#include <getopt.h>
+typedef uint8_t u8;
typedef uint16_t u16;
typedef uint32_t u32;
extern u16 *disassemble(u16 *pc, char *out);
static u16 image[65536] = { 0, };
+static u8 note[65536] = { 0, };
static u16 PC = 0;
static FILE *fin;
static const char *filename = "";
@@ -146,9 +148,10 @@ enum tokens {
tSHR, tAND, tBOR, tXOR, tIFE, tIFN, tIFG, tIFB,
tJSR,
tPOP, tPEEK, tPUSH, tSP, tPC, tO,
- tWORD,
+ tJMP, tMOV,
+ tDATA, tDAT, tDW, tWORD,
tCOMMA, tOBRACK, tCBRACK, tCOLON, tPLUS,
- tSTRING, tNUMBER, tEOF,
+ tSTRING, tQSTRING, tNUMBER, tEOF,
};
static const char *tnames[] = {
"A", "B", "C", "X", "Y", "Z", "I", "J",
@@ -156,14 +159,15 @@ static const char *tnames[] = {
"SHR", "AND", "BOR", "XOR", "IFE", "IFN", "IFG", "IFB",
"JSR",
"POP", "PEEK", "PUSH", "SP", "PC", "O",
- "WORD",
+ "JMP", "MOV",
+ "DATA", "DAT", "DW", "WORD",
",", "[", "]", ":", "+",
- "<STRING>", "<NUMBER>", "<EOF>",
+ "<STRING>", "<QUOTED-STRING>", "<NUMBER>", "<EOF>",
};
#define LASTKEYWORD tWORD
int _next(void) {
- char c;
+ char c, *x;
nextline:
if (!*lineptr) {
if (feof(fin)) return tEOF;
@@ -182,6 +186,28 @@ nextline:
case ']': return tCBRACK;
case ':': return tCOLON;
case '/': case ';': *lineptr = 0; goto nextline;
+ case '"':
+ x = tstring;
+ for (;;) {
+ switch((c = *lineptr++)) {
+ case 0:
+ die("unterminated string");
+ case '"':
+ *x = 0;
+ return tQSTRING;
+ case '\\':
+ switch((c = *lineptr++)) {
+ case 'n': *x++ = '\n'; break;
+ case 't': *x++ = '\t'; break;
+ case 'r': *x++ = '\r'; break;
+ default:
+ *x++ = c; break;
+ }
+ break;
+ default:
+ *x++ = c;
+ }
+ }
default:
if (isdigit(c) || ((c == '-') && isdigit(*lineptr))) {
tnumber = strtoul(lineptr-1, &lineptr, 0);
@@ -189,7 +215,7 @@ nextline:
}
if (isalpha(c) || c == '_') {
int n;
- char *x = tstring;
+ x = tstring;
lineptr--;
while (isalnum(*lineptr) || *lineptr == '_')
*x++ = tolower(*lineptr++);
@@ -221,15 +247,26 @@ void expect(int t) {
}
void assemble_imm_or_label(void) {
- next();
- if (token == tNUMBER) {
- image[PC++] = tnumber;
- } else if (token == tSTRING) {
- image[PC] = 0;
- use_label(tstring, PC++);
- } else {
- die("expected number or label");
- }
+ do {
+ next();
+ if (token == tNUMBER) {
+ note[PC] = 'd';
+ image[PC++] = tnumber;
+ } else if (token == tSTRING) {
+ note[PC] = 'd';
+ image[PC] = 0;
+ use_label(tstring, PC++);
+ } else if (token == tQSTRING) {
+ char *x = tstring;
+ while (*x) {
+ note[PC] = 'd';
+ image[PC++] = *x++;
+ }
+ } else {
+ die("expected number or label");
+ }
+ next();
+ } while (token == tCOMMA);
}
int assemble_operand(void) {
@@ -262,9 +299,23 @@ int assemble_operand(void) {
switch (token) {
case tA: case tB: case tC: case tX:
case tY: case tZ: case tI: case tJ:
- n = 0x08 | (token & 7);
+ n = token & 7;
+ next();
+ if (token == tCBRACK)
+ return 0x08 | n;
+ if ((token != tCOMMA) && (token != tPLUS))
+ die("expected , or +");
+ next();
+ if (token == tSTRING) {
+ use_label(tstring, PC);
+ image[PC++] = 0;
+ } else if (token == tNUMBER) {
+ image[PC++] = tnumber;
+ } else {
+ die("expected immediate value");
+ }
expect(tCBRACK);
- return n;
+ return 0x10 | n;
case tSTRING:
use_label(tstring, PC);
case tNUMBER:
@@ -291,7 +342,7 @@ int assemble_operand(void) {
}
void assemble_binop(int op) {
- int pc = PC++;
+ u16 pc = PC++;
int a, b;
a = assemble_operand();
expect(tCOMMA);
@@ -299,6 +350,11 @@ void assemble_binop(int op) {
image[pc] = op | (a << 4) | (b << 10);
}
+void assemble_jump(void) {
+ u16 pc = PC++;
+ image[pc] = 0x01c1 | (assemble_operand() << 10);
+}
+
void assemble(const char *fn) {
u16 pc, n;
fin = fopen(fn, "r");
@@ -308,16 +364,26 @@ void assemble(const char *fn) {
for (;;) {
next();
+again:
switch (token) {
case tEOF:
goto done;
+ case tSTRING:
+ expect(tCOLON);
+ set_label(tstring, PC);
+ continue;
case tCOLON:
expect(tSTRING);
set_label(tstring, PC);
continue;
- case tWORD:
+ case tWORD: case tDAT: case tDATA: case tDW:
assemble_imm_or_label();
+ goto again;
+ case tJMP: // alias for SET PC, ...
+ assemble_jump();
continue;
+ case tMOV: // alias for SET
+ token = tSET;
case tSET: case tADD: case tSUB: case tMUL:
case tDIV: case tMOD: case tSHL: case tSHR:
case tAND: case tBOR: case tXOR: case tIFE:
@@ -354,7 +420,10 @@ void emit(const char *fn, enum outformat format) {
while (pc < end) {
if (format == OUTFORMAT_PRETTY) {
- if (pc == dis) {
+ if (note[pc-image] == 'd') {
+ fprintf(fp, "%04x\n", *pc);
+ dis = pc + 1;
+ } else if (pc == dis) {
char out[128];
dis = disassemble(pc, out);
fprintf(fp, "%04x\t%04x:\t%s\n", *pc, (unsigned)(pc-image), out);
diff --git a/disassemble.c b/disassemble.c
@@ -39,7 +39,7 @@
typedef uint16_t u16;
static const char *opcode[] = {
- "XXX", "SET", "ADD", "SUB", "MUL", "DIV", "MOD", "SHL",
+ "XXX", "MOV", "ADD", "SUB", "MUL", "DIV", "MOD", "SHL",
"SHR", "AND", "BOR", "XOR", "IFE", "IFN", "IFG", "IFB",
};
static const char regs[8] = "ABCXYZIJ";
@@ -50,7 +50,7 @@ static u16 *dis_operand(u16 *pc, u16 n, char *out) {
} else if (n < 0x10) {
sprintf(out,"[%c]",regs[n & 7]);
} else if (n < 0x18) {
- sprintf(out,"[0x%04x+%c]",*pc++,regs[n & 7]);
+ sprintf(out,"[%c, 0x%04x]",regs[n & 7], *pc++);
} else if (n > 0x1f) {
sprintf(out,"%d", n - 0x20);
} else switch (n) {
@@ -71,6 +71,11 @@ u16 *disassemble(u16 *pc, char *out) {
u16 a = (n >> 4) & 0x3F;
u16 b = (n >> 10);
if (op > 0) {
+ if ((n & 0x03FF) == 0x1C1) {
+ sprintf(out,"JMP ");
+ pc = dis_operand(pc, b, out+strlen(out));
+ return pc;
+ }
sprintf(out,"%s ",opcode[op]);
pc = dis_operand(pc, a, out+strlen(out));
sprintf(out+strlen(out),", ");
