static struct expty transVar(Tr_level level, Tr_exp breakk, S_table venv, S_table tenv, A_var v) { if (!v) {return expTy(Tr_noExp(), Ty_Void());} /*!those several var is ugly*/ E_enventry x; struct expty et,et2; Ty_fieldList fl; Tr_exp trans; switch (v->kind) { case A_simpleVar:/* var id (a)*/ x = S_look(venv, v->u.simple); trans = Tr_noExp(); if (x && x->kind == E_varEntry) { trans = Tr_simpleVar(x->u.var.access, level); return expTy(trans, actual_ty(x->u.var.ty)); } else { EM_error(v->pos, "undefined var %s", S_name(v->u.simple)); return expTy(trans, Ty_Int()); } break; case A_fieldVar:/* var record (a.b)*/ et = transVar(level, breakk, venv, tenv, v->u.field.var); trans = Tr_noExp(); if (et.ty->kind != Ty_record) { EM_error(v->pos, "not a record type"); } else { int i = 0; for (fl = et.ty->u.record; fl; fl = fl->tail, i++) { /*fl is Ty_fieldList*/ if (fl->head->name == v->u.field.sym) { trans = Tr_fieldVar(et.exp, i); return expTy(trans, actual_ty(fl->head->ty)); } } EM_error(v->pos, "no such field in record %s", S_name(v->u.field.sym)); } return expTy(trans, Ty_Int()); break; case A_subscriptVar: /*var array (a[b])*/ et = transVar(level, breakk, venv, tenv, v->u.subscript.var); trans = Tr_noExp(); if (et.ty->kind != Ty_array) { EM_error(v->pos, "not a array type"); } else { et2 = transExp(level, breakk, venv, tenv, v->u.subscript.exp); if (et2.ty->kind != Ty_int) { EM_error(v->pos, "int required"); } else { trans = Tr_subscriptVar(et.exp, et2.exp); return expTy(trans, actual_ty(et.ty->u.array)); } } return expTy(trans, Ty_Int()); default: assert(0); } }
struct expty transVar_subscriptVar(Tr_level level, S_table venv, S_table tenv, A_var v, Temp_label breakk) { struct expty var = transVar(level, venv, tenv, v->u.subscript.var, breakk); struct expty sub = transExp(level, venv, tenv, v->u.subscript.exp, breakk); if (var.ty->kind != Ty_array) { EM_error(v->u.subscript.var->pos, "variable type '%s' is not array", type_msg(var.ty)); return expTy(NULL, Ty_Int()); } if (sub.ty->kind != Ty_int) { EM_error(v->u.subscript.exp->pos, "invalid types '%s' for array subscript", type_msg(sub.ty)); return expTy(NULL, Ty_Int()); } return expTy(Tr_subscriptVar(var.exp, sub.exp, level), actual_ty(var.ty->u.array)); }
static struct expty transVar(Tr_level level,Tr_exp breakk, S_table venv,S_table tenv,A_var v){ if (!v) { return expTy(Tr_noExp(), Ty_Void()); } E_enventry x; struct expty et,et2; Ty_fieldList fl; Tr_exp trans; switch(v->kind){ case A_simpleVar: /*var id*/ x=S_look(venv,v->u.simple); trans = Tr_noExp(); if (x&&x->kind==E_varEntry){ trans= Tr_simpleVar(x->u.var.access, level); return expTy(trans,actual_ty(x->u.var.ty)); }else{ //变量未定义 EM_error(v->pos, "undefined var %s", S_name(v->u.simple)); return expTy(trans, Ty_Int()); } break; case A_fieldVar:/* a.b a.b.c*/ //得到 a 的type 是 record还是 array还是 simplevar et=transVar(level,breakk,venv,tenv,v->u.field.var); trans = Tr_noExp(); if (et.ty->kind!=Ty_record) { EM_error(v->pos, "not a record type"); return expTy(NULL, Ty_Record(NULL)); }else{ int i=0; for (fl = et.ty->u.record;fl;fl=fl->tail,i++) { //地址比较 if (fl->head->name==v->u.field.sym) { trans = Tr_fieldVar(et.exp,i); return expTy(trans, actual_ty(fl->head->ty)); } } EM_error(v->pos, "no such field in record %s", S_name(v->u.field.sym)); } return expTy(trans, Ty_Int()); break; case A_subscriptVar:/*a[i]*/ et = transVar(level,breakk,venv, tenv, v->u.subscript.var); trans = Tr_noExp(); if (et.ty->kind!=Ty_array){ EM_error(v->pos, "not a array type"); }else{ et2=transExp(level,breakk,venv,tenv,v->u.subscript.exp); if (et2.ty->kind != Ty_int) { EM_error(v->pos, "int required"); }else{ trans = Tr_subscriptVar(et.exp, et2.exp); return expTy(trans, actual_ty(et.ty->u.array)); } } return expTy(trans, Ty_Int()); break; } }