Updating to reflect the latest work.

[zilutils.git] / zilasm / parser.c

diff --git a/zilasm/parser.c b/zilasm/parser.c
new file mode 100644 (file)
index 0000000..7f8af7e
--- /dev/null
+++ b/zilasm/parser.c
@@ -0,0 +1,171 @@
+/*
+ * parser.c -- part of ZilUtils/ZilAsm
+ *
+ * Copyright (C) 2016 Jason Self <j@jxself.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+#include <stdio.h>   /* fopen, fgets */
+#include <string.h>  /* strlen */
+
+#include "parser.h"
+#include "directives.h"
+#include "opcodes.h"
+#include "labels.h"
+
+#define iscomment(c)   ((c) == '#')
+#define isbindigit(c)  ((c) == '0' || (c) == '1')
+
+/* !!! TODO !!! */
+#define fatal_error(errmsg)
+#define PC NULL
+
+void checksep(const char *p)
+{
+       if (!*p || iscomment(*p) || isspace(*p)) return;
+       fatal_error("wrong chars");
+}
+
+const char *pass_spaces(const char *p)
+{
+       while(p && isspace(*p)) p++;
+       return (p && *p) ? p : NULL;
+}
+
+const char *pass_alnums(const char *p)
+{
+       while(p && isalnum(*p)) p++;
+       return (p && *p) ? p : NULL;
+}
+
+int tryparse_directive(const char *p)
+{
+       if (*p != '.')
+               return 0;
+       const char *a = p+1;
+       const char *b = pass_alnums(a);
+       checksep(b);
+       Directive_handler f = directive_lookup(a, b - a);
+       if (!f) return 0;
+       return (*f)(b);
+}
+
+int tryparse_assignment(const char *a, const char *b, const char *c)
+{
+       return 0;
+}
+
+int tryparse_label(const char *a, const char *b, const char *c)
+{
+       if (*(c+1) != ':') {
+               symtable_add2(Local_labels, a, b - a, PC);
+       } else if (*(c+2) != ':') {
+               symtable_add2(Global_labels, a, b - a, PC);
+       } else {
+               fatal_error("wrong label type");
+       }
+
+       while (*c++ == ':');
+       if (*c && ((c = pass_spaces(c)) != NULL) && *c)
+               return tryparse_instruction(c);
+       return 1;
+}
+
+int tryparse_name(const char *a)
+{
+       const char *b = pass_alnums(a);
+       const char *c = pass_spaces(b);
+
+       if (!c)        return 0;
+       if (*c == '=') return tryparse_assignment(a, b, c + 1);
+       if (*c == ':') return tryparse_label(a, b, c);
+       return 0;
+}
+
+int tryparse_instruction(const char *a)
+{
+       const char *b = pass_alnums(a);
+       ZOpcode *op = symtable_lookup2(Opcodes, a, b - a);
+       if (!op) return 0;
+       ZOpcode_flags flags = op->flags;
+       /* !!! TODO !!! */
+       return 0;
+}
+
+/*
+ *  Line can be one from: Comment, Global label, Local label, Directive, Name=Value, Instruction
+ */
+int parse_line(const char *p)
+{
+       for (; *p; p++) {
+               char c = *p;
+               int n;
+               if (isspace(c))                  continue;
+               if (iscomment(c))                return 0;
+               if (n = tryparse_directive(p))   return n;
+               if (n = tryparse_name(p))        return n;  // ..label or assignment
+               if (n = tryparse_instruction(p)) return n;
+               fatal_error("wrong line");
+       }
+       return 0;
+}
+
+int parse_file(const char *filename)
+{
+       FILE *fp = fopen(filename, "r");
+       if (!fp) fatal_error("wrong file");
+
+       const int MAX_LINESIZE = 1024;
+       char line[MAX_LINESIZE];
+       int newline_missing = 0;
+
+       while (fgets(line, MAX_LINESIZE, fp)) {
+               if (newline_missing) fatal_error("line too long");
+
+               int n = strlen(line);
+               if (!n) continue;
+
+               parse_line(line);
+
+               newline_missing = (line[n-1] != '\n');
+       }
+
+       close(fp);
+}
+
+/*
+
+line_passed() {
+    skip_spaces();
+    return (current_token == LINE_END || current_token == LINE_COMMENT);
+}
+
+if (line_passed()) continue;
+if (current_token == DIRECTIVE) {
+    if (!try_next_token(NAME))
+        fatal_error("directive contains incorrect chars")
+    handler = get_directive_handler(current_token);
+    if (!handler)
+        fatal error("unknown directive");
+    (*handler)(remaining_line);
+    if (line_passed()) continue;
+    fatal_error("unexpected line tail");
+} else if (current_token == NAME) {
+    skip_spaces();
+    if (current_token == ASSIGNMENT)
+}
+    
+
+*/