Papers/2012/aplas: paper/memo.txt annotate

author	Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
date	Tue, 12 Jun 2012 01:03:27 +0900
parents
children

rev	line source
7 bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	1 We have implemented Continuation based C (CbC).CbC is an extension of C, which has parameterized goto statement.
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	2 It is useful for finite state automaton or many core tasks.
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	3 Goto statement is a way to force tail call elimination.
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	4 The destination of goto statement is called Code Segment, which is actually a normal function of C.
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	5 To represent recursive function call, the type system of C is not enough, because
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	6 it has no recursive types.
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	7 We introduce __rectype keyword for recursive type, and it is implemented in GCC-4.6.0.
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	8 We will compare the conventional methods, __rectype keyword and a method using C structure.
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	9 Also we show usage of CbC and it's benchmark.
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	10
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	11
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	12
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	13
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	14
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	15
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	16 ・__rectype と GCC-4.6.0 における実装の説明
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	17 ・普通に宣言した場合と __rectype , 構造体を使用した場合に比較
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	18 ・それと CbC のベンチマークをみせる。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	19
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	20
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	21
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	22
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	23 ・Continuation based C
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	24
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	25 ・・CbC によるプログラミング
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	26 (なぜrectypeが必要になったのかを書く。1.引数の型チェックを行いたかった 2.Cの構文で宣言するとソースが長い、)
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	27 CbC では継続を基本としている。継続は goto の後にコードセグメントと引数をかくことで行われる。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	28 CbC においてはループ処理もこの goto による継続を用いて行われる。以下に loop の例を示す。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	29
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	30
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	31
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	32
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	33
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	34 今回我々は__rectype 構文を新たに実装した。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	35 __rectype はリカーシブタイプを宣言するものである。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	36 __rectype は引数に使われる型で、宣言中の引数の型と同じ型を持つ関数ポインタであることを示す。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	37
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	38 //ここでいうリカーシブタイプとは、同じ引数の型を持つタイプのことである。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	39 //C においては、以下のようなリカーシブタイプを宣言することはできない。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	40
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	41
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	42
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	43 void func( func *p )
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	44
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	45 関数ポインタを引数にもつ関数がある時、以下のように宣言される。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	46
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	47 __code csA( void (*p)() )
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	48
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	49 しかし、この宣言では p を使用する場合、p の引数の型チェックが行われない。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	50 p の引数の型チェックを行いたい時は以下の様に宣言しなければならない。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	51
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	52 __code csA( __code (p)(void ) ) {
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	53 goto p(csB);
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	54 }
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	55
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	56
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	57 これで p の引数の型チェックは行われるようになる。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	58 だが、これでもまだ正しくはない。なぜなら、p が引数として受け取った関数も引数を持つからである。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	59 引数で受け取る関数ポインタがそれぞれ引数で関数ポインタを持つ場合、以下のような宣言になる。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	60
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	61 __code csA( __code (p)(__code ()(__code ()( __code ()( __code (*)(,,) )))))
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	62
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	63 (,, の部分には同じような宣言が続いていく。)
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	64 C において引数で再帰的な関数ポインタを受け取る場合は上記のような宣言になり。宣言しきることができない。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	65 (再帰的な関数ポインタ…?)
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	66
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	67
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	68 そこで、__rectype 構文により以下のような宣言を行えるようにした。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	69
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	70 __code csA( __rectype *p )
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	71
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	72
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	73 この時、*p は csA のポインタを表している。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	74
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	75
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	76
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	77 ・__rectype の実装方法
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	78 __rectype の実装は、Generic Tree を書き換えることで行なっている。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	79 GCC では~のプログラムは次のようにGeneric Treeが作成される。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	80 void func(void (*)() );
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	81
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	82 fig1.
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	83
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	84 TREE_LIST には引数の情報が入っている。第一引数にはFUNCTION_TYPEへのポインタがさされているのがわかる。(第二引数にVOID_TYPEがあるのは固定長引数の為)
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	85 この第一引数が指すFUNCTION_TYPEを自分自身へと書き換えることで __rectype は実装されている。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	86
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	87 GCC 内部に実際に書き込んであるコードは以下になる。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	88 gcc/c-decl.c
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	89
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	90 cbc_return_f = NULL_TREE;
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	91 cbc_env = NULL_TREE;
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	92 if ( declspecs->typespec_word == cts_CbC_code )
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	93 {
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	94 cbc_set_codesegment(decl1);
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	95 /* implementation of rectype */
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	96 tree func_tree = TREE_TYPE(decl1);
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	97 // parm is PARM_DECL
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	98 tree parm = declarator->u.arg_info->parms;
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	99 while (parm) {
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	100 tree tmptype = parm;
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	101 if (!IS_RECTYPE(TREE_TYPE(tmptype))) {
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	102 parm = TREE_CHAIN(parm);
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	103 continue;
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	104 }
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	105 tree t = TREE_TYPE(tmptype);
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	106 while (TREE_CODE(t) == POINTER_TYPE) {
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	107 tmptype = t;
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	108 t= TREE_TYPE(tmptype);
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	109 }
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	110 TREE_TYPE(tmptype) = func_tree;
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	111 parm = TREE_CHAIN(parm);
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	112 }
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	113 }
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	114
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	115
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	116 decl1 は宣言中の自分自身にあたる変数である。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	117
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	118
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	119
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	120 ・__rectype 実装による問題
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	121 warning チェックによる無限再帰。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	122 __rectype を上記の方法で実装を行った所、以下の呼び出しをおこうとした場合 compile 中に segmen tation fault が発生した。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	123
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	124 __code csA(__rectype *p) {
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	125 goto p(3);
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	126 }
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	127
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	128 これは GCC においては以下の構文と同じである。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	129 void func(void (p)(void)) {
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	130 p(3);
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	131 }
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	132
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	133 上記の場合、GCC の内部では宣言された p の正しい引数の型を調べるためにポインタが辿られていく。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	134 その後、int の 3 が void の pointer へと convert(cast) される。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	135 しかし、__rectype の実装では pointer の先は csA となる。その csA の第一引数が関数ポインタだった場合その引数の型もみるのだが、この場合それが csA である。csA の引数の型をみにいき続けてしまい無限再帰となってしまっていた。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	136 この問題を解決するために、現在の実装では __rectype で宣言されたモノの型を辿らないようにしている。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	137 以下はその実装の部分である。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	138 gcc/c-family/c-pretty-print.c
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	139
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	140 static void
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	141 pp_c_abstract_declarator (c_pretty_printer *pp, tree t)
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	142 {
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	143 if (TREE_CODE (t) == POINTER_TYPE)
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	144 {
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	145 if (TREE_CODE (TREE_TYPE (t)) == ARRAY_TYPE
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	146 \|\| TREE_CODE (TREE_TYPE (t)) == FUNCTION_TYPE)
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	147 pp_c_right_paren (pp);
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	148 #ifndef noCbC
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	149 if(IS_RECTYPE(t)) return;
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	150 #endif
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	151 t = TREE_TYPE (t);
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	152 }
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	153
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	154 pp_direct_abstract_declarator (pp, t);
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	155 }
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	156
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	157
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	158 上記のコードの変数 t には引数の情報が入っている。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	159 ~行目の t = TREE_TYPE (t); におり、 t が pointer タイプだった場合そのタイプを辿るようになっているのが分かる。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	160 ここで、もし t が __rectype で宣言されたのならただ return を行うという処理を追加した。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	161 この実装により warning チェックの際の無限再帰を抑えることができた。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	162
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	163
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	164
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	165
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	166 ・構造体を使用してのリカーシブタイプ
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	167 リカーシブタイプの問題は引数を構造体にすることでも解決できる。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	168 以下はその例である。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	169
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	170 struct interface {
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	171 __code (*next)(struct interface);
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	172 };
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	173
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	174 __code csA(struct interface p) {
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	175 :
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	176 goto p.next(ds);
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	177 }
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	178
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	179 int main() {
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	180 struct interface ds = { print };
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	181 goto csA(ds);
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	182 return 0;
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	183 }
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	184
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	185 構造体で包むことで先に上げた関数ポインタの引数の型チェックの問題はクリアされる。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	186
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	187
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	188
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	189 ・GCC 版 CbC コンパイラのベンチマーク：
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	190 最後に、GCC 版 CbC コンパイラのベンチマークをMicro-C版 CbC と比較しながら以下に示す。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	191 使用したプログラムは conv1 プログラムで、内部では加算と継続を交互に行なっている。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	192
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	193
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	194
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	195
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	196
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	197
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	198
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	199
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	200
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	201
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	202
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	203 実装の確認と問題：
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	204 ・関数ポインタ中の引数の型に__rectype
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	205 __code csA(__code (p)(__rectype)) {
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	206 goto p(csA);
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	207 }
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	208
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	209 特に問題なく実行できる。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	210
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	211
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	212 ・typedef の問題
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	213 //typedef __code (*csPtr)(__rectype);
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	214 typedef __code (csPtr)(__rectype); // error
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	215
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	216 上記の場合、宣言自体失敗する。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	217 修正が必要。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	218
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	219 ・struct 内部での __rectype
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	220 struct interface {
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	221 __rectype *next;
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	222 };
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	223
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	224 __code csA(struct interface p) {
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	225 struct interface ds = { csA };
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	226 goto p.next(ds);
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	227 }
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	228
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	229 void main1() {
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	230 struct interface ds = { print };
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	231 goto csA(ds);
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	232 }
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	233
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	234 この時、errorがでる…が、一応 struct の宣言自体は通っている。
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	235 struct の宣言時に __rectype がきたらエラーが出るようにすべき…
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	236
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	237
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	238
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	239
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	240
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	241
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	242
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	243
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	244
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	245
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	246
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	247
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	248
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	249
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	250
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	251
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	252
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	253
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	254
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	255
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	256
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	257
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	258
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	259
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	260
bcacfe595c2a add memo.txt Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> parents: diff changeset	261

7

bcacfe595c2a add memo.txt