shithub: scc

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Simplify main loop in cc2

All the operations are performed over the current function, so it is
stupid to pass all the time the pointer to the beginning of the function.

--- a/cc2/cc2.h

+++ b/cc2/cc2.h

@@ -119,16 +119,18 @@

 extern Type Funct, l_int8,  l_int16,  l_int32,  l_int64,

                    l_uint8, l_uint16, l_uint32, l_uint64;

+extern Symbol *curfun;

+

 /* main.c */

 extern void error(unsigned nerror, ...);

 /* cgen.c */

-extern Node *genaddable(Node *np);

-extern void generate(Symbol *fun);

-extern void apply(Node *list[], Node *(*fun)(Node *));

+extern void addable(void);

+extern void generate(void);

+extern void apply(Node *(*fun)(Node *));

 /* parser.c */

-extern Symbol *parse(void);

+extern void parse(void);

 extern void prtree(Node *np);

 /* code.c */

@@ -136,5 +138,5 @@

 extern void writeout(void);

 /* optm.c */

-extern Node *optimize(Node *np);

+extern void optimize(void);

 extern Node *imm(TINT i, Type *tp);

--- a/cc2/cgen.c

+++ b/cc2/cgen.c

@@ -260,20 +260,20 @@

 }

 void

-generate(Symbol *fun)

+generate(void)

 {

 	extern char odebug;

-	char frame = fun->u.f.locals != 0 || odebug;

+	char frame = curfun->u.f.locals != 0 || odebug;

 	if (frame) {

 		code(PUSH, NULL, regs[IX]);

 		code(MOV, regs[IX], regs[SP]);

-		code(MOV, regs[HL], imm(-fun->u.f.locals, &l_int16));

+		code(MOV, regs[HL], imm(-curfun->u.f.locals, &l_int16));

 		code(ADD, regs[HL], regs[SP]);

 		code(MOV, regs[SP], regs[HL]);

 	}

-	apply(fun->u.f.body, applycgen);

+	apply(applycgen);

 	if (frame) {

 		code(MOV, regs[SP], regs[IX]);

@@ -339,4 +339,10 @@

 	if (np->complex == 0)

 		++np->complex;

 	return np;

+}

+

+void

+addable(void)

+{

+	apply(genaddable);

 }

--- a/cc2/main.c

+++ b/cc2/main.c

@@ -25,15 +25,29 @@

 	exit(EXIT_FAILURE);

 }

+bool

+moreinput(void)

+{

+	int c;

+

+repeat:

+	if (feof(stdin))

+		return 0;

+	if ((c = getchar()) == '\n' || c == EOF)

+		goto repeat;

+	ungetc(c, stdin);

+	return 1;

+}

+

 int

 main(void)

 {

-	Symbol *fun;

-

-	while (!feof(stdin) && (fun = parse())) {

-		apply(fun->u.f.body, optimize);

-		apply(fun->u.f.body, genaddable);

-		generate(fun);

+	while (moreinput()) {

+		parse();

+		optimize();

+		addable();

+		generate();

 		writeout();

 	}

+	return 0;

 }

--- a/cc2/optm.c

+++ b/cc2/optm.c

@@ -37,9 +37,15 @@

 	return np;			

 }

-Node *

-optimize(Node *np)

+static Node *

+opt(Node *np)

 {

 	np = optcasts(np, &np->type);

 	return np;

+}

+

+void

+optimize(void)

+{

+	apply(opt);

 }

--- a/cc2/parser.c

+++ b/cc2/parser.c

@@ -163,11 +163,11 @@

 }

 void

-apply(Node *list[], Node *(*fun)(Node *))

+apply(Node *(*fun)(Node *))

 {

-	Node *np;

+	Node **list, *np;

-	while (np = *list)

+	for (list = curfun->u.f.body; np = *list; ++list)

 		*list++ = (*fun)(np);

 }

@@ -503,7 +503,7 @@

 	sym->u.v.off = 1-curfun->u.f.locals;

 }

-Symbol *

+void

 parse(void)

 {

 	void (*fun)(char *tok);

@@ -537,17 +537,8 @@

 			fun = globdcl;

 			break;

 		case '}':

-			if (!curfun)

-				error(ESYNTAX);

-			return curfun;

-		case EOF:

-			if (ferror(stdin))

-				error(EFERROR, strerror(errno));

 			if (curfun)

-				goto syntax_error;

-			return NULL;

-		case '\n':

-			continue;

+				return;

 		default:

 			goto syntax_error;

 		}

@@ -562,11 +553,6 @@

 		(*fun)(strtok(line, "\t"));

 	}

-found_eof:

-

-

-	if (!curfun)

-		return curfun;

 syntax_error:

 	error(ESYNTAX);

 }