ref: bd985d9e0ba924bfb73ff0abb5004f1be04ffa34
dir: /flow.c/
#include <stdio.h> #include "symbol.h" #include "tokens.h" #include "syntax.h" static struct node *stmt(void); static struct node * _goto(void) { register struct node *np; expect(GOTO); expect(IDEN); if (yyval.sym->ns != NS_LABEL) yyval.sym = lookup(yytext, NS_LABEL, CTX_ANY); np = node1(OGOTO, nodesym(yyval.sym)); expect(';'); return np; } static struct node * _while(void) { register struct node *cond; expect(WHILE); expect('('); cond = expr(); expect(')'); return node2(OWHILE, cond, stmt()); } static struct node * _do(void) { register struct node *cond, *body; expect(DO); body = stmt(); expect(WHILE); expect('('); cond = expr(); expect(')'); expect(';'); return node2(ODO, body, cond); } static struct node * _for(void) { register struct node *exp1, *exp2, *exp3; expect(FOR); expect('('); exp1 = (yytoken != ';') ? expr() : NULL; expect(';'); exp2 = (yytoken != ';') ? expr() : NULL; expect(';'); exp3 = (yytoken != ')') ? expr() : NULL; expect(')'); return node2(OFOR, node3(OFEXP, exp1, exp2, exp3), stmt()); } static struct node * _if(void) { register struct node *cond, *body; expect(IF); expect('('); cond = expr(); expect(')'); body = stmt(); return node3(OIF, cond, body, (accept(ELSE)) ? stmt() : NULL); } static struct node * _switch(void) { register struct node *cond; expect(SWITCH); expect('('); cond = expr(); expect(')'); return node2(OSWITCH, cond, stmt()); } static struct node * label(void) { register struct symbol *sym; if (!ahead(':')) { register struct node *np = expr(); /* it is an identifier */ expect(';'); /* not a label */ return np; } sym = lookup(yytext, NS_LABEL, CTX_ANY); if (sym->ctx != CTX_ANY) error("label '%s' already defined", yytext); sym->ctx = curctx; next(), next(); /* skip IDEN and ':' */ return node2(OLABEL, nodesym(sym), stmt()); } static struct node * stmt(void) { register struct node *np; switch (yytoken) { case '{': return compound(); case SWITCH: return _switch(); case IF: return _if(); case FOR: return _for(); case DO: return _do(); case WHILE: return _while(); case CONTINUE: case BREAK: case RETURN: case GOTO: return _goto(); case CASE: /* TODO */ case DEFAULT: /* TODO */ case IDEN: return label(); } np = expr(); expect(';'); return np; } struct node * compound(void) { register struct node *np = nodecomp(); expect('{'); new_ctx(); while (decl()) /* nothing */; while (!accept('}')) addstmt(np, stmt()); del_ctx(); return np; }