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Simplify stmt

We can use a function pointer for this function, but then we need
to pass the state to all the possible statements. This is not a
problem, because we can ignore the parameters we are not using,
and the code of stmt will be smaller because we have only one
function call.

--- a/cc1/stmt.c

+++ b/cc1/stmt.c

@@ -43,7 +43,7 @@

 }

 static void

-stmtexp(void)

+stmtexp(Symbol *lbreak, Symbol *lcont, Caselist *lswitch)

 {

 	if (yytoken != ';')

 		emitexp(expr());

@@ -62,7 +62,7 @@

 }

 static void

-While(Caselist *lswitch)

+While(Symbol *lbreak, Symbol *lcont, Caselist *lswitch)

 {

 	Symbol *begin, *cond, *end;

 	Node *np;

@@ -84,7 +84,7 @@

 }

 static void

-For(Caselist *lswitch)

+For(Symbol *lbreak, Symbol *lcont, Caselist *lswitch)

 {

 	Symbol *begin, *cond, *end;

 	Node *econd = NULL, *einc = NULL;

@@ -117,7 +117,7 @@

 }

 static void

-Dowhile(Caselist *lswitch)

+Dowhile(Symbol *lbreak, Symbol *lcont, Caselist *lswitch)

 {

 	Symbol *begin = label("", 1), *end = label("", 1);

@@ -132,7 +132,7 @@

 }

 static void

-Return(void)

+Return(Symbol *lbreak, Symbol *lcont, Caselist *lswitch)

 {

 	Node *np;

 	Type *tp = curfun->type->type;

@@ -155,7 +155,7 @@

 }

 static void

-Break(Symbol *lbreak)

+Break(Symbol *lbreak, Symbol *lcont, Caselist *lswitch)

 {

 	expect(BREAK);

 	if (!lbreak)

@@ -164,17 +164,20 @@

 	expect(';');

 }

+static void stmt(Symbol *lbreak, Symbol *lcont, Caselist *lswitch);

+

 static void

-Label(void)

+Label(Symbol *lbreak, Symbol *lcont, Caselist *lswitch)

 {

 	emitlabel(label(yytext, 1));

 	expect(IDEN);

 	expect(':');

+	stmt(lbreak, lcont, lswitch);

 }

 static void

-Continue(Symbol *lcont)

+Continue(Symbol *lbreak, Symbol *lcont, Caselist *lswitch)

 {

 	expect(CONTINUE);

 	if (!lcont)

@@ -184,7 +187,7 @@

 }

 static void

-Goto(void)

+Goto(Symbol *lbreak, Symbol *lcont, Caselist *lswitch)

 {

 	expect(GOTO);

@@ -196,13 +199,14 @@

 }

 static void

-Switch(Symbol *lcont)

+Switch(Symbol *lbreak, Symbol *lcont, Caselist *lswitch)

 {

 	Caselist lcase = {.nr = 0, .head = NULL, .deflabel = NULL};

 	struct scase *p;

-	Symbol *lbreak = label("", 1), *lcond = label("", 1);

 	Node *cond;

+	Symbol *lcond = label("", 1);

+	lbreak = label("", 1);

 	expect(SWITCH);

 	expect ('(');

 	cond = eval(expr());

@@ -298,27 +302,24 @@

 static void

 stmt(Symbol *lbreak, Symbol *lcont, Caselist *lswitch)

 {

+	void (*fun)(Symbol *lbreak, Symbol *lcont, Caselist *lswitch);

-repeat:

 	switch (yytoken) {

-	case '{':      context(lbreak, lcont, lswitch); break;

-	case RETURN:   Return(); break;

-	case WHILE:    While(lswitch); break;

-	case FOR:      For(lswitch); break;

-	case DO:       Dowhile(lswitch); break;

-	case IF:       If(lbreak, lcont, lswitch); break;

-	case BREAK:    Break(lbreak); break;

-	case CONTINUE: Continue(lcont); break;

-	case GOTO:     Goto(); break;

-	case SWITCH:   Switch(lcont); break;

-	case CASE:     Case(lbreak, lcont, lswitch); break;

-	case DEFAULT:  Default(lbreak, lcont, lswitch); break;

-	case IDEN:

-		if (ahead() == ':') {

-			Label();

-			goto repeat;

-		}

-	default:       stmtexp(); break;

+	case '{':      fun = context;  break;

+	case RETURN:   fun = Return;   break;

+	case WHILE:    fun = While;    break;

+	case FOR:      fun = For;      break;

+	case DO:       fun = Dowhile;  break;

+	case IF:       fun = If;       break;

+	case BREAK:    fun = Break;    break;

+	case CONTINUE: fun = Continue; break;

+	case GOTO:     fun = Goto;     break;

+	case SWITCH:   fun = Switch;   break;

+	case CASE:     fun = Case;     break;

+	case DEFAULT:  fun = Default;  break;

+	default:       fun = stmtexp;  break;

+	case IDEN:     fun = (ahead() == ':') ? Label : stmtexp; break;

 	}

+	(*fun)(lbreak, lcont, lswitch);

 }