shithub: scc

Download patch

ref: 371dbd08d948b3679df21e8304ecfb20724d0976
parent: f2207c0e27fe98dc65368ffb82553c50e20e0458
author: Roberto E. Vargas Caballero <[email protected]>
date: Thu Jul 17 11:09:27 EDT 2014 

First version of cc2

This is a first version of cc2 that allows to read a small subset
of the intermediate code. It is a good initial point for it.


--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,5 @@
 
-DIRS = lib cc1
+DIRS = lib cc1 cc2
 
 all clean:
 	for i in $(DIRS) ;\
--- /dev/null
+++ b/cc2/Makefile
@@ -1,0 +1,18 @@
+
+OBJS = main.o parser.o
+
+CPPFLAGS = -I../inc
+LDFLAGS = -L../lib
+LIBS = -lcc
+
+all: cc2
+
+$(OBJS): ../inc/cc.h ../inc/sizes.h
+
+cc2: $(OBJS) ../lib/libcc.a
+	$(CC) $(LDFLAGS) $(CFLAGS) $(OBJS) $(LIBS) -o $@
+
+clean:
+	rm -f $(OBJS)
+	rm -f cc2
+
--- /dev/null
+++ b/cc2/main.c
@@ -1,0 +1,20 @@
+
+#include <stddef.h>
+
+#include <cc.h>
+#include <sizes.h>
+
+extern void parse(void);
+
+void
+esyntax(void)
+{
+	die("incorrect intermediate file");
+}
+
+int
+main(void)
+{
+	parse();
+}
+
--- /dev/null
+++ b/cc2/parser.c
@@ -1,0 +1,197 @@
+
+#include <ctype.h>
+#include <stdio.h>
+
+#include <cc.h>
+#include <sizes.h>
+
+#define NR_STACKSIZ 32
+#define NR_NODEPOOL 128
+#define NR_EXPRESSIONS 64
+
+typedef struct node {
+	char op;
+	char type;
+	union {
+		short id;
+		int imm;
+	} u;
+	struct node *left, *right;
+} Node;
+
+static Node *stack[NR_STACKSIZ], **stackp = stack;
+static Node *listexp[NR_EXPRESSIONS], **listp = &listexp[0];
+static Node nodepool[NR_NODEPOOL], *newp = nodepool;
+char vars[1024];
+
+extern void esyntax(void);
+
+static short
+getid(void)
+{
+	int i;
+
+	scanf("%d", &i);
+	if (i < 0 || i >= 1024)
+		esyntax();
+	return i;
+}
+
+static Node *
+newnode(void)
+{
+	if (newp == &nodepool[NR_NODEPOOL])
+		esyntax();
+	return newp++;
+}
+
+static void
+push(Node *np)
+{
+	if (stackp == &stack[NR_STACKSIZ])
+		esyntax();
+	*stackp++ = np;
+}
+
+static Node *
+pop(void)
+{
+	if (stackp == stack)
+		esyntax();
+	return *--stackp;
+}
+
+static void
+link(Node *np)
+{
+	if (listp == &listexp[NR_EXPRESSIONS])
+		esyntax();
+	*listp++ = np;
+}
+
+static char
+gettype(void)
+{
+	char t;
+
+	switch (t = getchar()) {
+	case L_INT16: case L_INT8:
+		return t;
+	default:
+		esyntax();
+	}
+}
+
+static void
+variable(char op)
+{
+	Node *np = newnode();
+
+	np->op = op;
+	np->type = vars[np->u.id = getid()];
+	np->left = np->right = NULL;
+	push(np);
+}
+
+static void
+immediate(char op)
+{
+	Node *np = newnode();
+
+	np->op = '#';
+	np->type = L_INT;
+	scanf("%d", &np->u.imm);
+	np->left = np->right = NULL;
+	push(np);
+}
+
+static void
+operator(char op)
+{
+	Node *np = newnode();
+
+	np->left = pop();
+	np->right = pop();
+	np->type = gettype();
+	np->op = op;
+	push(np);
+}
+
+static Node *
+getroot(void)
+{
+	Node *np = *--stackp;
+	if (stackp != stack)
+		esyntax();
+	return np;
+}
+
+static void (*optbl[])(char) = {
+	['+'] = operator,
+	['-'] = operator,
+	['*'] = operator,
+	['/'] = operator,
+	['A'] = variable,
+	['T'] = variable,
+	['G'] = variable,
+	['#'] = immediate,
+	['\177'] = NULL
+};
+
+static void
+expression(void)
+{
+	int c;
+	void (*fun)(char);
+
+	do {
+		if (!isprint(c = getchar()))
+			esyntax();
+		if ((fun = optbl[c]) == NULL)
+			esyntax();
+		(*fun)(c);
+	} while ((c = getchar()) == '\t');
+
+	if (c != '\n')
+		esyntax();
+	link(getroot());
+}
+
+static void
+declaration(char sclass)
+{
+	short id;
+
+	id = getid();
+	getchar(); /* skip tab */
+	vars[id] = gettype();
+	if (getchar() != '\n')
+		esyntax();
+}
+
+int
+parse(void)
+{
+	int c;
+
+	while ((c = getchar()) != EOF) {
+		switch (c) {
+		case '\t':
+			expression();
+			break;
+		case 'L':
+			/* label */
+			break;
+		case 'S':
+			/* struct */
+			break;
+		case 'T': case 'A': case 'G': case 'R':
+			declaration(c);
+			break;
+		default:
+			esyntax();
+			break;
+		}
+	}
+}
+
--- a/inc/cc.h
+++ b/inc/cc.h
@@ -30,6 +30,7 @@
 #define L_UINT16    'N'
 #define L_UINT32    'Z'
 #define L_UINT64    'O'
+#define L_INT       L_INT16
 
 #define L_VOID      '0'
 #define L_POINTER   'P'
@@ -60,4 +61,4 @@
 extern char *xstrdup(const char *s);
 extern void *xrealloc(void *buff, register size_t size);
 
-#endif
\ No newline at end of file
+#endif