diff options
Diffstat (limited to 'semantics.c')
| -rw-r--r-- | semantics.c | 163 |
1 files changed, 133 insertions, 30 deletions
diff --git a/semantics.c b/semantics.c index b66f93b..2871e9c 100644 --- a/semantics.c +++ b/semantics.c @@ -25,6 +25,18 @@ CTable_t ctable_create(Hashfunc_t hfunc) { return ct; } #endif +void ctable_destory(CTable_t ct) { + int i; + for (i = 0; i < MAX_TABLE_SIZE; i++) + { + CTNode *p, *np; + for (p = ct->head[i]; p; p = np) + { + np = p->next; + free(p); + } + } +} extern void print_error(char *, char *, int, int, int); extern char *load_line(int); @@ -73,6 +85,8 @@ CScope_t cscope_create() { CScope_t p = NEW(CScope); p->lvl = -1; p->top = NULL; + p->func = NULL; + p->inside_loop = 0; #ifdef CIBIC_DEBUG p->tvar = ctable_create(bkdr_hash, ctable_cvar_print); p->ttype = ctable_create(bkdr_hash, ctable_ctype_print); @@ -476,12 +490,17 @@ CVar_t semantics_params(CNode *p, CScope_t scope) { p = p->chd; if (p->type == NOP) return NULL; /* void arguments */ CVar_t params = semantics_p_decl(p, scope), tail = params; - cscope_push_var(scope, params); +#ifdef CIBIC_DEBUG + CTable_t tparams = ctable_create(bkdr_hash, ctable_cvar_print); +#else + CTable_t tparams = ctable_create(bkdr_hash); +#endif + ctable_insert(tparams, params->name, params, 0); for (p = p->next; p; p = p->next) { CVar_t var = semantics_p_decl(p, scope); if (scope) /* params inside a function definition */ - if (!cscope_push_var(scope, var)) + if (!ctable_insert(tparams, var->name, var, 0)) { sprintf(err_buff, "redefinition of parameter '%s'", var->name); ERROR(var->ast); @@ -489,6 +508,7 @@ CVar_t semantics_params(CNode *p, CScope_t scope) { tail->next = var; tail = var; } + ctable_destory(tparams); return params; } @@ -644,7 +664,7 @@ CVar_t semantics_decl(CNode *p, CScope_t scope) { } if (!useful) { - /* TODO: useless typename warning */ + /* useless typename warning */ sprintf(err_buff, "useless declaration"); WARNING(type->ast); } @@ -1165,13 +1185,94 @@ ExpType semantics_exp(CNode *p, CScope_t scope) { return res; } +CVar_t semantics_stmt(CNode *p, CScope_t scope); + +CVar_t semantics_if(CNode *p, CScope_t scope) { + ExpType exp = semantics_exp(p->chd, scope); + CNode *body1 = p->chd->next, + *body2 = body1->next; + CVar_t res; + if (!IS_SCALAR(exp.type->type)) + { + sprintf(err_buff, "a scalar is required in 'if' condition"); + ERROR(p->chd); + } + cscope_enter(scope); + res = semantics_stmt(body1, scope); + cscope_exit(scope); + if (body2->type != NOP) + { + cscope_enter(scope); + res->next = semantics_stmt(p->chd->next->next, scope); + cscope_exit(scope); + } + return res; +} + +CVar_t semantics_for(CNode *p, CScope_t scope) { + ExpType exp = semantics_exp(p->chd->next, scope); + semantics_exp(p->chd, scope); + semantics_exp(p->chd->next->next, scope); + CVar_t res; + if (!IS_SCALAR(exp.type->type)) + { + sprintf(err_buff, "a scalar is required in 'for' condition"); + ERROR(p->chd->next); + } + cscope_enter(scope); + scope->inside_loop++; + res = semantics_stmt(p->chd->next->next->next, scope); + scope->inside_loop--; + cscope_exit(scope); + return res; +} + +CVar_t semantics_while(CNode *p, CScope_t scope) { + ExpType exp = semantics_exp(p->chd, scope); + CVar_t res; + if (!IS_SCALAR(exp.type->type)) + { + sprintf(err_buff, "a scalar is required in 'while' condition"); + ERROR(p->chd); + } + cscope_enter(scope); + scope->inside_loop++; + res = semantics_stmt(p->chd->next, scope); + scope->inside_loop--; + cscope_exit(scope); + return res; +} + +CVar_t semantics_check_loop(CNode *p, CScope_t scope, const char *stmt_name) { + if (!scope->inside_loop) + { + sprintf(err_buff, "%s statement not within a loop", stmt_name); + ERROR(p->chd); + } + return NULL; +} +CVar_t semantics_return(CNode *p, CScope_t scope) { + assert(scope->func); + CType_t rt = scope->func->rec.func.ret; + if (p->chd->type != NOP) + { + if (rt->type == CVOID) + { + sprintf(err_buff, "'return' with a value, in function returning void"); + WARNING(p->chd); + } + semantics_exp(p->chd, scope); + exp_check_aseq_(rt, p->chd->ext.type, p->chd); + } + return NULL; +} + CVar_t semantics_comp(CNode *, CScope_t); CVar_t semantics_stmt(CNode *p, CScope_t scope) { CHECK_TYPE(p, STMT); switch (p->rec.subtype) { case STMT_EXP: - /* TODO: expression handle */ semantics_exp(p->chd, scope); break; case STMT_COMP: @@ -1183,29 +1284,17 @@ CVar_t semantics_stmt(CNode *p, CScope_t scope) { return res; } case STMT_IF: - /* TODO: `if' statement */ - ; - break; + return semantics_if(p, scope); case STMT_FOR: - /* TODO: `for' statement */ - ; - break; + return semantics_for(p, scope); case STMT_WHILE: - /* TODO: `while' statement */ - ; - break; + return semantics_while(p, scope); case STMT_CONT: - /* TODO: `continue' statement */ - ; - break; + return semantics_check_loop(p, scope, "continue"); case STMT_BREAK: - /* TODO: `break' statement */ - ; - break; + return semantics_check_loop(p, scope, "break"); case STMT_RET: - /* TODO: `return' statement */ - ; - break; + return semantics_return(p, scope); default: assert(0); } return NULL; @@ -1244,20 +1333,34 @@ CVar_t semantics_comp(CNode *p, CScope_t scope) { CVar_t semantics_func(CNode *p, CScope_t scope) { CHECK_TYPE(p, FUNC_DEF); - CNode *chd = p->chd->next; - CType_t func = ctype_create(chd->rec.strval, CFUNC, p), funco; - CVar_t res = cvar_create(func->name, func, p), old; + CVar_t head = semantics_p_declr(p->chd->next, semantics_type_spec(p->chd, scope)); + CType_t func = ctype_create(head->name, CFUNC, p), funco; + CVar_t res = cvar_create(head->name, func, p), old = NULL; + CNode *chd = p->chd->next->next; + + func->rec.func.ret = head->type; + /* check return type */ + if (!type_is_complete(head->type)) + { + sprintf(err_buff, "return type is an incomplete type"); + ERROR(p->chd); + } - chd = chd->next; - func->rec.func.ret = semantics_type_spec(p->chd, scope); /* check return type */ + scope->func = func; cscope_enter(scope); /* enter into function local scope */ func->rec.func.params = semantics_params(chd, scope); /* check params */ + if (cscope_push_var(scope, res)) + old = res; + { + CVar_t p; + for (p = func->rec.func.params; p; p = p->next) + cscope_push_var(scope, p); + } func->rec.func.local = semantics_comp(chd->next, scope); /* check comp */ func->rec.func.body = chd->next; cscope_exit(scope); /* exit from local scope */ - if (cscope_push_var(scope, res)) - old = res; - else + + if (!old) { old = cscope_lookup_var(scope, res->name); funco = old->type; |