Updating to reflect the latest work.

[zilutils.git] / zilasm / symtable.c

diff --git a/zilasm/symtable.c b/zilasm/symtable.c
new file mode 100644 (file)
index 0000000..d1dd902
--- /dev/null
+++ b/zilasm/symtable.c
@@ -0,0 +1,144 @@
+/*
+ * symtable.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 <string.h>
+#include <stdlib.h>
+#include <assert.h>
+
+#include "symtable.h"
+
+#define FIELD_SIZE(Typ,Field)  (sizeof(((Typ*)0)->Field))
+
+Symtable* symtable_create(unsigned elems_count, unsigned name_size, unsigned elem_size)
+{
+       size_t n = elems_count * (name_size + elem_size) + sizeof(Symtable) - FIELD_SIZE(Symtable, contents);
+       Symtable *p = malloc(n);
+       assert(p);
+       bzero(p, n);
+       p->elems_count = elems_count;
+       p->name_size   = name_size;
+       p->elem_size   = elem_size;
+       return p;
+}
+
+void symtable_destroy(Symtable *p)
+{
+       assert(p);
+       free(p);
+}
+
+static unsigned name2pos(const Symtable *p, const char *name, unsigned namelen)
+{
+       assert(p);
+       unsigned key = 0;
+       while(namelen--)
+               key = ((key << 1) | (*name++));
+       return key % p->elems_count;
+}
+
+static char *getsym(const Symtable *p, unsigned pos)
+{
+       //assert(p);   //already checked by caller
+       //assert(pos < p->elems_count);
+       return ((char*)p) + sizeof(Symtable) - FIELD_SIZE(Symtable, contents) + (pos * p->elem_size);
+}
+
+void* symtable_lookup2(const Symtable *p, const char *name, unsigned namelen)
+{
+       assert(p);
+       assert(name);
+       assert(namelen > 0);
+       assert(namelen < p->name_size);
+
+       unsigned start = name2pos(p, name, namelen);
+       unsigned pos = start;
+
+       do {
+               char *s = getsym(p, pos);
+               if (!*s)
+                       return NULL;
+               if (!memcmp(name, s, namelen))
+                       return s + p->name_size;
+               if (++pos >= p->elems_count)
+                       pos = 0;
+       } while(pos != start);
+
+       return NULL;
+}
+
+void* symtable_lookup(const Symtable *p, const char *name)
+{
+       assert(name);
+       return symtable_lookup2(p, name, strlen(name));
+}
+
+void* symtable_add(Symtable *p, const char *name, void *contents)
+{
+       assert(name);
+       return symtable_add2(p, name, strlen(name), contents);
+}
+
+void* symtable_add2(Symtable *p, const char *name, unsigned namelen, void *contents)
+{
+       assert(p);
+       assert(name);
+       assert(namelen > 0 && namelen < p->name_size);
+       assert(contents);
+
+       unsigned start = name2pos(p, name, namelen);
+       unsigned pos = start;
+
+       do {
+               char *s = getsym(p, pos);
+               if (!*s) {
+                       memcpy(s, name, namelen + 1);
+                       s[namelen] = '\0';
+                       memcpy(s + p->name_size, contents, p->elem_size);
+                       return s + p->name_size;
+               }
+               if (!memcmp(name, s, namelen) && s[namelen] == '\0') {
+                       /* TODO!! report error */
+                       return NULL;  /* ..already added */
+               }
+               if (++pos >= p->elems_count)
+                       pos = 0;
+       } while(pos != start);
+
+       /* TODO!! report overflow */
+       return NULL;
+       /* TODO!!! */
+}
+
+static int sortfunc(const void *a, const void *b)
+{
+       const char *s1 = a;
+       const char *s2 = b;
+       if (!*s1 && !*s2) return  0;
+       if (!*s1)         return  1;
+       if (!*s2)         return -1;
+       return strcmp(s1, s2);
+}
+
+void symtable_sort(Symtable *p)
+{
+       assert(p);
+       qsort(getsym(p, 0), p->elems_count, p->elem_size + p->name_size, sortfunc);
+}
+
+/* END */