From: mpi Date: Tue, 31 Aug 2021 08:39:26 +0000 (+0000) Subject: Rewrite grammar to implement operator precedence without using %right or %prec. X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=89f393010521bde64362e81d604132e2a60dd425;p=openbsd Rewrite grammar to implement operator precedence without using %right or %prec. Arithmetic operator should now behave as expeted and tests can now be written without superfluous parenthesis, for example: syscall:select:entry /($1 == 0) || (pid == $1)/ { } Can now be written: syscall:select:entry /$1 == 0 || pid == $1/ { } While here improve filter debugging support. --- diff --git a/usr.sbin/btrace/TODO b/usr.sbin/btrace/TODO index c38454e7afe..aad8a6657f4 100644 --- a/usr.sbin/btrace/TODO +++ b/usr.sbin/btrace/TODO @@ -12,6 +12,5 @@ Missing language features: Improvements: -- implement arithmetic operator precedence - rewrite stmt_printf() to not use strings internally - look at collision in map hash diff --git a/usr.sbin/btrace/bt_parse.y b/usr.sbin/btrace/bt_parse.y index b079c8b4a17..2a7ac72f38b 100644 --- a/usr.sbin/btrace/bt_parse.y +++ b/usr.sbin/btrace/bt_parse.y @@ -1,4 +1,4 @@ -/* $OpenBSD: bt_parse.y,v 1.35 2021/08/30 11:57:45 mpi Exp $ */ +/* $OpenBSD: bt_parse.y,v 1.36 2021/08/31 08:39:26 mpi Exp $ */ /* * Copyright (c) 2019-2021 Martin Pieuchot @@ -56,6 +56,9 @@ SLIST_HEAD(, bt_var) g_variables; /* List of local variables, cleaned for each new rule. */ SLIST_HEAD(, bt_var) l_variables; +struct bt_arg g_nullba = BA_INITIALIZER(0, B_AT_LONG); +struct bt_arg g_maxba = BA_INITIALIZER(LONG_MAX, B_AT_LONG); + struct bt_rule *br_new(struct bt_probe *, struct bt_filter *, struct bt_stmt *, enum bt_rtype); struct bt_probe *bp_new(const char *, const char *, const char *, int32_t); @@ -124,13 +127,8 @@ static int pflag; %type probe pname %type filter %type action stmt stmtlist -%type expr vargs mentry mexpr pargs term - -%right '=' -%nonassoc OP_EQ OP_NE OP_LE OP_LT OP_GE OP_GT OP_LAND OP_LOR -%left '&' '|' -%left '+' '-' -%left '/' '*' +%type pat vargs mentry mpat pargs +%type expr term fterm factor %% grammar : /* empty */ @@ -165,64 +163,80 @@ lvar : '$' STRING { $$ = $2; } mentry : gvar '[' vargs ']' { $$ = bm_find($1, $3); } ; -mexpr : MOP0 '(' ')' { $$ = ba_new(NULL, $1); } - | MOP1 '(' expr ')' { $$ = ba_new($3, $1); } +mpat : MOP0 '(' ')' { $$ = ba_new(NULL, $1); } + | MOP1 '(' pat ')' { $$ = ba_new($3, $1); } + | pat + ; + +pat : CSTRING { $$ = ba_new($1, B_AT_STR); } | expr ; -expr : CSTRING { $$ = ba_new($1, B_AT_STR); } +filter : /* empty */ { $$ = NULL; } + | '/' expr ENDFILT { $$ = bc_new(NULL, B_AT_OP_NE, $2); } + ; + +/* + * Give higher precedence to: + * 1. && and || + * 2. ==, !=, <<, <, >=, >, +, =, &, ^, | + * 3. * and / + */ +expr : expr OP_LAND term { $$ = ba_op(B_AT_OP_LAND, $1, $3); } + | expr OP_LOR term { $$ = ba_op(B_AT_OP_LOR, $1, $3); } | term ; -filter : /* empty */ { $$ = NULL; } - | '/' term ENDFILT { $$ = bc_new(NULL, B_AT_OP_NE, $2); } +term : term OP_EQ fterm { $$ = ba_op(B_AT_OP_EQ, $1, $3); } + | term OP_NE fterm { $$ = ba_op(B_AT_OP_NE, $1, $3); } + | term OP_LE fterm { $$ = ba_op(B_AT_OP_LE, $1, $3); } + | term OP_LT fterm { $$ = ba_op(B_AT_OP_LT, $1, $3); } + | term OP_GE fterm { $$ = ba_op(B_AT_OP_GE, $1, $3); } + | term OP_GT fterm { $$ = ba_op(B_AT_OP_GT, $1, $3); } + | term '+' fterm { $$ = ba_op(B_AT_OP_PLUS, $1, $3); } + | term '-' fterm { $$ = ba_op(B_AT_OP_MINUS, $1, $3); } + | term '&' fterm { $$ = ba_op(B_AT_OP_BAND, $1, $3); } + | term '^' fterm { $$ = ba_op(B_AT_OP_XOR, $1, $3); } + | term '|' fterm { $$ = ba_op(B_AT_OP_BOR, $1, $3); } + | fterm + ; + +fterm : fterm '*' factor { $$ = ba_op(B_AT_OP_MULT, $1, $3); } + | fterm '/' factor { $$ = ba_op(B_AT_OP_DIVIDE, $1, $3); } + | factor ; -term : '(' term ')' { $$ = $2; } - | term OP_EQ term { $$ = ba_op(B_AT_OP_EQ, $1, $3); } - | term OP_NE term { $$ = ba_op(B_AT_OP_NE, $1, $3); } - | term OP_LE term { $$ = ba_op(B_AT_OP_LE, $1, $3); } - | term OP_LT term { $$ = ba_op(B_AT_OP_LT, $1, $3); } - | term OP_GE term { $$ = ba_op(B_AT_OP_GE, $1, $3); } - | term OP_GT term { $$ = ba_op(B_AT_OP_GT, $1, $3); } - | term OP_LAND term { $$ = ba_op(B_AT_OP_LAND, $1, $3); } - | term OP_LOR term { $$ = ba_op(B_AT_OP_LOR, $1, $3); } - | term '+' term { $$ = ba_op(B_AT_OP_PLUS, $1, $3); } - | term '-' term { $$ = ba_op(B_AT_OP_MINUS, $1, $3); } - | term '*' term { $$ = ba_op(B_AT_OP_MULT, $1, $3); } - | term '/' term { $$ = ba_op(B_AT_OP_DIVIDE, $1, $3); } - | term '&' term { $$ = ba_op(B_AT_OP_BAND, $1, $3); } - | term '|' term { $$ = ba_op(B_AT_OP_BOR, $1, $3); } - | staticv { $$ = ba_new($1, B_AT_LONG); } - | BUILTIN { $$ = ba_new(NULL, $1); } - | lvar { $$ = bl_find($1); } - | gvar { $$ = bg_find($1); } +factor : '(' expr ')' { $$ = $2; } + | staticv { $$ = ba_new($1, B_AT_LONG); } + | BUILTIN { $$ = ba_new(NULL, $1); } + | lvar { $$ = bl_find($1); } + | gvar { $$ = bg_find($1); } | mentry ; -vargs : expr - | vargs ',' expr { $$ = ba_append($1, $3); } +vargs : pat + | vargs ',' pat { $$ = ba_append($1, $3); } ; -pargs : term - | gvar ',' expr { $$ = ba_append(bg_find($1), $3); } +pargs : expr + | gvar ',' pat { $$ = ba_append(bg_find($1), $3); } ; NL : /* empty */ | '\n' ; stmt : ';' NL { $$ = NULL; } - | gvar '=' expr { $$ = bg_store($1, $3); } - | lvar '=' expr { $$ = bl_store($1, $3); } - | gvar '[' vargs ']' '=' mexpr { $$ = bm_insert($1, $3, $6); } + | gvar '=' pat { $$ = bg_store($1, $3); } + | lvar '=' pat { $$ = bl_store($1, $3); } + | gvar '[' vargs ']' '=' mpat { $$ = bm_insert($1, $3, $6); } | FUNCN '(' vargs ')' { $$ = bs_new($1, $3, NULL); } - | FUNC1 '(' expr ')' { $$ = bs_new($1, $3, NULL); } + | FUNC1 '(' pat ')' { $$ = bs_new($1, $3, NULL); } | FUNC0 '(' ')' { $$ = bs_new($1, NULL, NULL); } | F_DELETE '(' mentry ')' { $$ = bm_op($1, $3, NULL); } | F_PRINT '(' pargs ')' { $$ = bs_new($1, $3, NULL); } - | gvar '=' OP1 '(' expr ')' { $$ = bh_inc($1, $5, NULL); } - | gvar '=' OP4 '(' expr ',' vargs ')' { $$ = bh_inc($1, $5, $7); } + | gvar '=' OP1 '(' pat ')' { $$ = bh_inc($1, $5, NULL); } + | gvar '=' OP4 '(' pat ',' vargs ')' { $$ = bh_inc($1, $5, $7); } ; stmtlist: stmt diff --git a/usr.sbin/btrace/bt_parser.h b/usr.sbin/btrace/bt_parser.h index 67481456a59..ec77e345e1e 100644 --- a/usr.sbin/btrace/bt_parser.h +++ b/usr.sbin/btrace/bt_parser.h @@ -1,4 +1,4 @@ -/* $OpenBSD: bt_parser.h,v 1.17 2021/08/30 11:57:45 mpi Exp $ */ +/* $OpenBSD: bt_parser.h,v 1.18 2021/08/31 08:39:26 mpi Exp $ */ /* * Copyright (c) 2019-2021 Martin Pieuchot @@ -156,6 +156,7 @@ struct bt_arg { B_AT_OP_MULT, B_AT_OP_DIVIDE, B_AT_OP_BAND, + B_AT_OP_XOR, B_AT_OP_BOR, B_AT_OP_EQ, B_AT_OP_NE, @@ -198,6 +199,8 @@ struct bt_stmt { extern struct bt_ruleq g_rules; /* Successfully parsed rules. */ extern int g_nprobes; /* # of probes to attach */ +extern struct bt_arg g_nullba; +extern struct bt_arg g_maxba; int btparse(const char *, size_t, const char *, int); diff --git a/usr.sbin/btrace/btrace.c b/usr.sbin/btrace/btrace.c index 785a4ed7c69..bd63c77c17d 100644 --- a/usr.sbin/btrace/btrace.c +++ b/usr.sbin/btrace/btrace.c @@ -1,4 +1,4 @@ -/* $OpenBSD: btrace.c,v 1.39 2021/08/30 11:57:45 mpi Exp $ */ +/* $OpenBSD: btrace.c,v 1.40 2021/08/31 08:39:26 mpi Exp $ */ /* * Copyright (c) 2019 - 2020 Martin Pieuchot @@ -104,6 +104,8 @@ __dead void xabort(const char *, ...); void debug(const char *, ...); void debugx(const char *, ...); const char *debug_rule_name(struct bt_rule *); +void debug_dump_term(struct bt_arg *); +void debug_dump_expr(struct bt_arg *); void debug_dump_filter(struct bt_rule *); struct dtioc_probe_info *dt_dtpis; /* array of available probes */ @@ -867,15 +869,15 @@ stmt_store(struct bt_stmt *bs, struct dt_evt *dtev) bool stmt_test(struct bt_stmt *bs, struct dt_evt *dtev) { - struct bt_arg *bop; + struct bt_arg *ba; if (bs == NULL) return true; assert(bs->bs_var == NULL); - bop = SLIST_FIRST(&bs->bs_args); + ba = SLIST_FIRST(&bs->bs_args); - return baexpr2long(bop, dtev) != 0; + return baexpr2long(ba, dtev) != 0; } /* @@ -1022,73 +1024,75 @@ long baexpr2long(struct bt_arg *ba, struct dt_evt *dtev) { static long recursions; - struct bt_arg *a, *b; - long first, second, result; + struct bt_arg *lhs, *rhs; + long lval, rval, result; if (++recursions >= __MAXOPERANDS) errx(1, "too many operands (>%d) in expression", __MAXOPERANDS); - a = ba->ba_value; - first = ba2long(a, dtev); + lhs = ba->ba_value; + rhs = SLIST_NEXT(lhs, ba_next); - b = SLIST_NEXT(a, ba_next); - - if (b == NULL) { - second = 0; + lval = ba2long(lhs, dtev); + if (rhs == NULL) { + rval = 0; } else { - assert(SLIST_NEXT(b, ba_next) == NULL); - second = ba2long(b, dtev); + assert(SLIST_NEXT(rhs, ba_next) == NULL); + rval = ba2long(rhs, dtev); } switch (ba->ba_type) { case B_AT_OP_PLUS: - result = first + second; + result = lval + rval; break; case B_AT_OP_MINUS: - result = first - second; + result = lval - rval; break; case B_AT_OP_MULT: - result = first * second; + result = lval * rval; break; case B_AT_OP_DIVIDE: - result = first / second; + result = lval / rval; break; case B_AT_OP_BAND: - result = first & second; + result = lval & rval; + break; + case B_AT_OP_XOR: + result = lval ^ rval; break; case B_AT_OP_BOR: - result = first | second; + result = lval | rval; break; case B_AT_OP_EQ: - result = (first == second); + result = (lval == rval); break; case B_AT_OP_NE: - result = (first != second); + result = (lval != rval); break; case B_AT_OP_LE: - result = (first <= second); + result = (lval <= rval); break; case B_AT_OP_LT: - result = (first < second); + result = (lval < rval); break; case B_AT_OP_GE: - result = (first >= second); + result = (lval >= rval); break; case B_AT_OP_GT: - result = (first > second); + result = (lval > rval); break; case B_AT_OP_LAND: - result = (first && second); + result = (lval && rval); break; case B_AT_OP_LOR: - result = (first || second); + result = (lval || rval); break; default: xabort("unsuported operation %d", ba->ba_type); } - debug("ba=%p '%ld %s %ld = %ld'\n", ba, first, ba_name(ba), second, - result); + debug("ba=%p eval '%ld %s %ld = %d'\n", ba, lval, ba_name(ba), + rval, result); --recursions; @@ -1106,6 +1110,40 @@ ba_name(struct bt_arg *ba) return "pid"; case B_AT_BI_TID: return "tid"; + case B_AT_BI_COMM: + return "comm"; + case B_AT_BI_CPU: + return "cpu"; + case B_AT_BI_NSECS: + return "nsecs"; + case B_AT_BI_KSTACK: + return "kstack"; + case B_AT_BI_USTACK: + return "ustack"; + case B_AT_BI_ARG0: + return "arg0"; + case B_AT_BI_ARG1: + return "arg1"; + case B_AT_BI_ARG2: + return "arg2"; + case B_AT_BI_ARG3: + return "arg3"; + case B_AT_BI_ARG4: + return "arg4"; + case B_AT_BI_ARG5: + return "arg5"; + case B_AT_BI_ARG6: + return "arg6"; + case B_AT_BI_ARG7: + return "arg7"; + case B_AT_BI_ARG8: + return "arg8"; + case B_AT_BI_ARG9: + return "arg9"; + case B_AT_BI_ARGS: + return "args"; + case B_AT_BI_RETVAL: + return "retval"; case B_AT_OP_PLUS: return "+"; case B_AT_OP_MINUS: @@ -1116,6 +1154,8 @@ ba_name(struct bt_arg *ba) return "/"; case B_AT_OP_BAND: return "&"; + case B_AT_OP_XOR: + return "^"; case B_AT_OP_BOR: return "|"; case B_AT_OP_EQ: @@ -1394,20 +1434,56 @@ debugx(const char *fmt, ...) } void -debug_dump_filter(struct bt_rule *r) +debug_dump_term(struct bt_arg *ba) { - if (r->br_filter != NULL) { - struct bt_stmt *bs = r->br_filter->bf_condition; - struct bt_arg *bop = SLIST_FIRST(&bs->bs_args); - struct bt_arg *a, *b; + switch (ba->ba_type) { + case B_AT_LONG: + debugx("%s", ba2str(ba, NULL)); + break; + case B_AT_OP_PLUS ... B_AT_OP_LOR: + debug_dump_expr(ba); + break; + default: + debugx("%s", ba_name(ba)); + } +} - a = bop->ba_value; - b = SLIST_NEXT(a, ba_next); +void +debug_dump_expr(struct bt_arg *ba) +{ + struct bt_arg *lhs, *rhs; + + lhs = ba->ba_value; + rhs = SLIST_NEXT(lhs, ba_next); + + /* Left */ + debug_dump_term(lhs); + + /* Right */ + if (rhs != NULL) { + debugx(" %s ", ba_name(ba)); + debug_dump_term(rhs); + } else { + if (ba->ba_type != B_AT_OP_NE) + debugx(" %s NULL", ba_name(ba)); + } +} - debugx(" / %s %s %s /", ba_name(a), ba_name(bop), - (b != NULL) ? ba_name(b) : "NULL"); +void +debug_dump_filter(struct bt_rule *r) +{ + struct bt_stmt *bs; + + if (r->br_filter == NULL) { + debugx("\n"); + return; } - debugx("\n"); + + bs = r->br_filter->bf_condition; + + debugx(" /"); + debug_dump_expr(SLIST_FIRST(&bs->bs_args)); + debugx("/\n"); } const char * diff --git a/usr.sbin/btrace/map.c b/usr.sbin/btrace/map.c index 85e675d94f4..1313b19465b 100644 --- a/usr.sbin/btrace/map.c +++ b/usr.sbin/btrace/map.c @@ -1,4 +1,4 @@ -/* $OpenBSD: map.c,v 1.12 2021/01/21 13:19:25 mpi Exp $ */ +/* $OpenBSD: map.c,v 1.13 2021/08/31 08:39:26 mpi Exp $ */ /* * Copyright (c) 2020 Martin Pieuchot @@ -178,9 +178,6 @@ map_insert(struct map *map, const char *key, struct bt_arg *bval, return map; } -static struct bt_arg nullba = BA_INITIALIZER(0, B_AT_LONG); -static struct bt_arg maxba = BA_INITIALIZER(LONG_MAX, B_AT_LONG); - /* Print at most `top' entries of the map ordered by value. */ void map_print(struct map *map, size_t top, const char *name) @@ -192,10 +189,10 @@ map_print(struct map *map, size_t top, const char *name) if (map == NULL) return; - bprev = &maxba; + bprev = &g_maxba; for (i = 0; i < top; i++) { mcur = NULL; - bhigh = &nullba; + bhigh = &g_nullba; RB_FOREACH(mep, map, map) { if (bacmp(mep->mval, bhigh) >= 0 && bacmp(mep->mval, bprev) < 0 &&