diff options
| -rw-r--r-- | miscutils/bc.c | 49 |
1 files changed, 34 insertions, 15 deletions
diff --git a/miscutils/bc.c b/miscutils/bc.c index bdee14de4..7be2d0b9b 100644 --- a/miscutils/bc.c +++ b/miscutils/bc.c @@ -3437,11 +3437,11 @@ static BC_STATUS zdc_lex_token(BcLex *l) // break; case '\n': // '\n' is BC_LEX_NLINE, not BC_LEX_WHITESPACE - // (and "case '\n'" is not just empty here) + // (and "case '\n':" is not just empty here) // only to allow interactive dc have a way to exit // "parse" stage of "parse,execute" loop - // on '\n', not on _next_ token (which would mean - // command are not executed on pressing <enter>). + // on <enter>, not on _next_ token (which would mean + // commands are not executed on pressing <enter>). // IOW: typing "1p<enter>" should print "1" _at once_, // not after some more input. l->t.t = BC_LEX_NLINE; @@ -6673,6 +6673,9 @@ static BC_STATUS zbc_vm_process(const char *text) if (s) RETURN_STATUS(s); while (G.prs.l.t.t != BC_LEX_EOF) { + BcInstPtr *ip; + BcFunc *f; + dbg_lex("%s:%d G.prs.l.t.t:%d, parsing...", __func__, __LINE__, G.prs.l.t.t); if (IS_BC) { // FIXME: "eating" of stmt delimiters is coded inconsistently @@ -6695,6 +6698,15 @@ static BC_STATUS zbc_vm_process(const char *text) bc_program_reset(); break; } + + ip = (void*)G.prog.exestack.v; +#if SANITY_CHECKS + if (G.prog.exestack.len != 1) // should have only main's IP + bb_error_msg_and_die("BUG:call stack"); + if (ip->func != BC_PROG_MAIN) + bb_error_msg_and_die("BUG:not MAIN"); +#endif + f = bc_program_func_BC_PROG_MAIN(); // bc discards strings, constants and code after each // top-level statement in the "main program". // This prevents "yes 1 | bc" from growing its memory @@ -6706,22 +6718,10 @@ static BC_STATUS zbc_vm_process(const char *text) // but bc stores function strings/constants in per-function // storage. if (IS_BC) { - BcFunc *f; - BcInstPtr *ip = (void*)G.prog.exestack.v; - #if SANITY_CHECKS if (G.prog.results.len != 0) // should be empty bb_error_msg_and_die("BUG:data stack"); - if (G.prog.exestack.len != 1) // should have only main's IP - bb_error_msg_and_die("BUG:call stack"); - if (ip->func != BC_PROG_MAIN) - bb_error_msg_and_die("BUG:not MAIN"); #endif -//bb_error_msg("ip->func:%d >idx:%d >len:%d", ip->func, ip->inst_idx, ip->len); - f = bc_program_func_BC_PROG_MAIN(); -//bb_error_msg("MAIN->code.len:%d >strs.len:%d >consts.len:%d", f->code.len, f->strs.len, f->consts.len); // labels, autos, nparams - bc_vec_pop_all(&f->code); - ip->inst_idx = 0; IF_BC(bc_vec_pop_all(&f->strs);) IF_BC(bc_vec_pop_all(&f->consts);) } else { @@ -6731,7 +6731,26 @@ static BC_STATUS zbc_vm_process(const char *text) s = zbc_lex_next(&G.prs.l); if (s) RETURN_STATUS(s); } + + if (G.prog.results.len == 0 + && G.prog.vars.len == 0 + ) { + // If stack is empty and no registers exist (TODO: or they are all empty), + // we can get rid of accumulated strings and constants. + // In this example dc process should not grow + // its memory consumption with time: + // yes 1pc | dc + IF_DC(bc_vec_pop_all(&G.prog.strs);) + IF_DC(bc_vec_pop_all(&G.prog.consts);) + } + // The code is discarded always (below), thus this example + // should also not grow its memory consumption with time, + // even though its data stack is not empty: + // { echo 1; yes dk; } | dc } + // We drop generated and executed code for both bc and dc: + bc_vec_pop_all(&f->code); + ip->inst_idx = 0; } dbg_lex_done("%s:%d done", __func__, __LINE__); |