Import Dev86-0.0.4.tar.gzv0.0.4

1 files changed, 161 insertions, 0 deletions

diff --git a/unproto/symbol.c b/unproto/symbol.c
new file mode 100644
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--- /dev/null
+++ b/unproto/symbol.c
@@ -0,0 +1,161 @@
+/*++
+/* NAME
+/*	symbol 3
+/* SUMMARY
+/*	rudimentary symbol table package
+/* SYNOPSIS
+/*	#include "symbol.h"
+/*
+/*	void sym_init()
+/*
+/*	void sym_enter(name, type)
+/*	char *name;
+/*	int type;
+/*
+/*	struct symbol *sym_find(name)
+/*	char *name;
+/* DESCRIPTION
+/*	This is a rudimentary symbol-table package, just enough to
+/*	keep track of a couple of C keywords.
+/*
+/*	sym_init() primes the table with C keywords. At present, most of
+/*	the keywords that have to do with types are left out.
+/*	We need a different strategy to detect type definitions because
+/*	we do not keep track of typedef names.
+/*
+/*	sym_enter() adds an entry to the symbol table.
+/*
+/*	sym_find() locates a symbol table entry (it returns 0 if
+/*	it is not found).
+/* AUTHOR(S)
+/*	Wietse Venema
+/*	Eindhoven University of Technology
+/*	Department of Mathematics and Computer Science
+/*	Den Dolech 2, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
+/* LAST MODIFICATION
+/*	91/11/30 21:10:33
+/* VERSION/RELEASE
+/*	1.2
+/*--*/
+
+static char symbol_sccsid[] = "@(#) symbol.c 1.2 91/11/30 21:10:33";
+
+/* C library */
+
+extern char *strcpy();
+extern char *malloc();
+
+/* Application-specific stuff */
+
+#include "error.h"
+#include "token.h"
+#include "symbol.h"
+
+#define	SYM_TABSIZE	20
+
+static struct symbol *sym_tab[SYM_TABSIZE] = {0,};
+
+/* More string stuff. Maybe it should go to an #include file. */
+
+#define	STREQ(x,y)	(*(x) == *(y) && strcmp((x),(y)) == 0)
+
+/* hash - hash a string; original author: P. J. Weinberger at Bell Labs. */
+
+static unsigned hash(s, size)
+register char *s;
+unsigned size;
+{
+    register unsigned long h = 0;
+    register unsigned long g;
+
+    /*
+     * For a performance comparison with the hash function presented in K&R,
+     * first edition, see the "Dragon" book by Aho, Sethi and Ullman.
+     */
+
+    while (*s) {
+	h = (h << 4) + *s++;
+	if (g = (h & 0xf0000000)) {
+	    h ^= (g >> 24);
+	    h ^= g;
+	}
+    }
+    return (h % size);
+}
+
+/* sym_enter - enter symbol into table */
+
+void    sym_enter(name, type)
+char   *name;
+int     type;
+{
+    struct symbol *s;
+    int     where;
+
+    if ((s = (struct symbol *) malloc(sizeof(*s))) == 0
+	|| (s->name = malloc(strlen(name) + 1)) == 0)
+	error(1, "out of memory");
+    (void) strcpy(s->name, name);
+    s->type = type;
+
+    where = hash(name, SYM_TABSIZE);
+    s->next = sym_tab[where];
+    sym_tab[where] = s;
+}
+
+/* sym_find - locate symbol definition */
+
+struct symbol *sym_find(name)
+register char *name;
+{
+    register struct symbol *s;
+
+    /*
+     * This function is called for almost every "word" token, so it better be
+     * fast.
+     */
+
+    for (s = sym_tab[hash(name, SYM_TABSIZE)]; s; s = s->next)
+	if (STREQ(name, s->name))
+	    return (s);
+    return (0);
+}
+
+ /*
+  * Initialization data for symbol table. We do not enter keywords for types.
+  * We use a different strategy to detect type declarations because we do not
+  * keep track of typedef names.
+  */
+
+struct sym {
+    char   *name;
+    int     tokno;
+};
+
+static struct sym syms[] = {
+    "if", TOK_CONTROL,
+    "else", TOK_CONTROL,
+    "while", TOK_CONTROL,
+    "do", TOK_CONTROL,
+    "switch", TOK_CONTROL,
+    "case", TOK_CONTROL,
+    "default", TOK_CONTROL,
+    "return", TOK_CONTROL,
+    "continue", TOK_CONTROL,
+    "break", TOK_CONTROL,
+    "goto", TOK_CONTROL,
+    "struct", TOK_COMPOSITE,
+    "union", TOK_COMPOSITE,
+    0,
+};
+
+/* sym_init - enter known keywords into symbol table */
+
+void    sym_init()
+{
+    register struct sym *p;
+
+    for (p = syms; p->name; p++)
+	sym_enter(p->name, p->tokno);
+}
+