6.6 initial commit (better ../6.5)

11 files changed, 318 insertions, 0 deletions

diff --git a/6.6/Makefile b/6.6/Makefile
new file mode 100644
index 0000000..0900c66
--- /dev/null
+++ b/6.6/Makefile
@@ -0,0 +1,14 @@
+objects = main.o hash.o word.o getch.o def.o
+CC = gcc
+CFLAGS = -Wvla -Wall -Wextra -Wstrict-prototypes -Wmissing-prototypes -fsanitize=address
+
+def : $(objects)
+	$(CC) $(CFLAGS) -o def $(objects)
+
+main.o : word.h hash.h def.h
+def.o : hash.h word.h getch.h def.h
+word.o : getch.h
+
+.PHONY : clean
+clean:
+	rm def $(objects)
diff --git a/6.6/def.c b/6.6/def.c
new file mode 100644
index 0000000..b3fef1f
--- /dev/null
+++ b/6.6/def.c
@@ -0,0 +1,72 @@
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <ctype.h>
+#include "word.h"
+#include "hash.h"
+#include "getch.h"
+#include "def.h"
+
+#define MAXWORD	100
+
+static void error(char c, char *s);
+void skipblanks(void);
+int endline(char *s, int lim);
+
+void getdef(struct nlist *hashtab[], uint32_t hashsize)
+{
+	char dir[MAXWORD], name[MAXWORD], def[MAXWORD];
+
+	skipblanks();
+	if (!isalpha(getword(dir, MAXWORD))) {
+		error(dir[0], "getdef: expecting a directive after #");
+	} else if (!strcmp(dir, "define")) {
+		skipblanks();
+		if (!isalpha(getword(name, MAXWORD))) {
+		 	error(name[0], "getdef: non-alpha in undef");
+		} else {
+			if(endline(def, MAXWORD) == MAXWORD)
+				error(def[0], "getdef: incomplete define");
+			else
+				install(hashtab, hashsize, name, def);
+		}
+	} else if (!strcmp(dir, "undef")) {
+		skipblanks();
+		if (isalpha(getword(name, MAXWORD)))
+			undef(hashtab, hashsize, name);
+		else
+		 	error(name[0], "getdef: non-alpha in undef");
+	} else {
+		error(dir[0], "getdef: directive invalid or not implemented");
+	}
+}
+
+static void error(char c, char *s)
+{
+	printf("err: %s\n", s);
+
+	while (c != EOF && c != '\n')
+		c = getch();
+}
+
+void skipblanks(void)
+{
+	char c;
+
+	while (isblank(c = getch()))
+		;
+
+	ungetch(c);
+}
+
+int endline(char *s, int lim)
+{
+	int i;
+
+	skipblanks();
+	for (i = 0; i < lim - 1; ++i)
+		if ((s[i] = getch()) == EOF || s[i] == '\n')
+			break;
+	s[i] = '\0';
+	return lim - i;
+}
diff --git a/6.6/def.h b/6.6/def.h
new file mode 100644
index 0000000..f2f2533
--- /dev/null
+++ b/6.6/def.h
@@ -0,0 +1,3 @@
+#include <stdint.h>
+
+void getdef(struct nlist *hashtab[], uint32_t hashsize);
diff --git a/6.6/getch.c b/6.6/getch.c
new file mode 100644
index 0000000..f271434
--- /dev/null
+++ b/6.6/getch.c
@@ -0,0 +1,23 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <error.h>
+#include <errno.h>
+#include "getch.h"
+
+#define MAXBUFF 100
+
+int top;
+char buff[MAXBUFF];
+
+char getch(void)
+{
+	return (top > 0) ? buff[--top] : getchar();
+}
+
+void ungetch(char c)
+{
+	if (top < MAXBUFF)
+		buff[top++] = c;
+	else
+	 	error(EXIT_FAILURE, ENOBUFS, "getch");
+}
diff --git a/6.6/getch.h b/6.6/getch.h
new file mode 100644
index 0000000..b0e086b
--- /dev/null
+++ b/6.6/getch.h
@@ -0,0 +1,2 @@
+char getch(void);
+void ungetch(char c);
diff --git a/6.6/hash.c b/6.6/hash.c
new file mode 100644
index 0000000..5d5d6f8
--- /dev/null
+++ b/6.6/hash.c
@@ -0,0 +1,117 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include "hash.h"
+
+void nlfree(struct nlist *p);
+uint32_t hash(char *s, uint32_t hashsize);
+void pnl(struct nlist *np);
+
+uint32_t hash(char *s, uint32_t hashsize)
+{
+	uint32_t hashval;
+
+	for (hashval = 0; *s != '\0'; ++s)
+		hashval = *s + 31*hashval;
+
+	return hashval % hashsize;
+}
+
+struct nlist *lookup(struct nlist *hashtab[], uint32_t hashsize, char *s)
+{
+	struct nlist *np;
+
+	for (np = hashtab[hash(s, hashsize)]; np != NULL; np = np->next)
+		if (!strcmp(s, np->name))
+			return np;
+
+	return NULL;
+}
+
+struct nlist *install(struct nlist *hashtab[], uint32_t hashsize,
+		      char *name, char *defn)
+{
+	struct nlist *np;
+	uint32_t hashval;
+
+	if ((np = lookup(hashtab, hashsize, name)) == NULL) {
+		np = (struct nlist *) malloc(sizeof(*np));
+		if (np == NULL || (np->name = strdup(name)) == NULL) {
+			nlfree(np);
+			return NULL;
+		}
+
+		hashval = hash(name, hashsize);
+		np->next = hashtab[hashval];
+		hashtab[hashval] = np;
+	} else {
+		free(np->defn);
+	}
+
+	if ((np->defn = strdup(defn)) == NULL) {
+		undef(hashtab, hashsize, name);
+		return NULL;
+	}
+
+	return np;
+}
+
+void undef(struct nlist *hashtab[], uint32_t hashsize, char *name)
+{
+	struct nlist *np, *prev;
+	uint32_t h;
+
+	prev = NULL;
+	h = hash(name, hashsize);
+	for (np = hashtab[h]; np != NULL; prev = np, np = np->next)
+		if (!strcmp(name, np->name))
+			break;
+
+	if (np != NULL) {
+		if (prev == NULL)
+			hashtab[h] = np->next;
+		else
+			prev->next = np->next;
+
+		np->next = NULL;
+		nlfree(np);
+		return;
+	}
+}
+
+void pnl(struct nlist *np)
+{
+	if (np != NULL) {
+		pnl(np->next);
+		printf("%10s %s\n", np->name, np->defn);
+	}
+}
+
+void phashtab(struct nlist *hashtab[], int lim)
+{
+	int i;
+
+	for (i = 0; i < lim; ++i)
+		pnl(hashtab[i]);
+}
+
+void nlfree(struct nlist *p)
+{
+	if (p != NULL ) {
+		nlfree(p->next);
+		if (p->defn != NULL)
+			free(p->defn);
+		if (p->name != NULL)
+			free(p->name);
+		free(p);
+	}
+}
+
+void hashfree(struct nlist *hashtab[], int lim)
+{
+	int i;
+
+	for (i = 0; i < lim; ++i)
+		nlfree(hashtab[i]);
+}
diff --git a/6.6/hash.h b/6.6/hash.h
new file mode 100644
index 0000000..b6bdf82
--- /dev/null
+++ b/6.6/hash.h
@@ -0,0 +1,19 @@
+#include <stdint.h>
+
+#ifndef HASH_H
+
+struct nlist {
+	struct nlist *next;
+	char *name;
+	char *defn;
+};
+
+#define HASH_H
+#endif
+
+struct nlist *install(struct nlist *hashtab[], uint32_t hashsize,
+		      char *name, char *defn);
+struct nlist *lookup(struct nlist *hashtab[], uint32_t hashsize, char *s);
+void undef(struct nlist *hashtab[], uint32_t hashsize, char *name);
+void phashtab(struct nlist *hastab[], int hashsize);
+void hashfree(struct nlist *hastab[], int hashsize);
diff --git a/6.6/main.c b/6.6/main.c
new file mode 100644
index 0000000..19a7323
--- /dev/null
+++ b/6.6/main.c
@@ -0,0 +1,32 @@
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include "word.h"
+#include "hash.h"
+#include "def.h"
+
+#define MAXWORD		100
+#define HASHSIZE	100
+
+struct nlist *hashtab[HASHSIZE];
+
+int main(void)
+{
+	char word[MAXWORD];
+	struct nlist *np, *temp;
+
+	while (getword(word, MAXWORD) != EOF) {
+		if (!strcmp(word, "#")) {
+			getdef(hashtab, HASHSIZE);
+		} else if (!isalpha(word[0])) {
+			printf("%s", word);
+		} else if ((np = lookup(hashtab, HASHSIZE, word)) == NULL) {
+			printf("%s", word);
+		} else {
+			ungetword(np->defn);
+		}
+	}
+
+	hashfree(hashtab, HASHSIZE);
+	return 0;
+}
diff --git a/6.6/test.c b/6.6/test.c
new file mode 100644
index 0000000..d6e7240
--- /dev/null
+++ b/6.6/test.c
@@ -0,0 +1,8 @@
+#define	sneed	feed
+#define	chuck	seek
+#define	based	soy
+#undef	chuck
+
+int based;
+int chuck;
+int soy;
diff --git a/6.6/word.c b/6.6/word.c
new file mode 100644
index 0000000..7f26dfd
--- /dev/null
+++ b/6.6/word.c
@@ -0,0 +1,26 @@
+#include <ctype.h>
+#include <string.h>
+#include "getch.h"
+#include "word.h"
+
+char getword(char *word, int lim)
+{
+	char *w = word;
+
+	if (isalpha(*w = getch())) {
+		while ((isalnum(*++w = getch()) || *w == '_') && --lim > 0)
+			;
+		ungetch(*w--);
+	}
+
+	*++w = '\0';
+	return word[0];
+}
+
+void ungetword(char *word)
+{
+	int len;
+
+	for (len = strlen(word); len >= 0; --len)
+		ungetch(word[len]);
+}
diff --git a/6.6/word.h b/6.6/word.h
new file mode 100644
index 0000000..9bcfcf8
--- /dev/null
+++ b/6.6/word.h
@@ -0,0 +1,2 @@
+char getword(char *word, int lim);
+void ungetword(char *word);