From 6e42b89b8d136316e1b97b56cf885e8ef9d64caf Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Mon, 1 Aug 2011 18:16:43 +0200 Subject: [PATCH] hush: fix remaining known two bugs with IFS expansion. Closes 4027. function old new delta expand_vars_to_list 1054 1140 +86 parse_stream 2425 2479 +54 expand_on_ifs 258 310 +52 builtin_umask 133 132 -1 done_word 820 779 -41 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 3/2 up/down: 192/-42) Total: 150 bytes Signed-off-by: Denys Vlasenko --- shell/hush.c | 82 +++++++++++++------ .../hush_test/hush-parsing/starquoted2.right | 3 + .../hush_test/hush-parsing/starquoted2.tests | 6 +- 3 files changed, 61 insertions(+), 30 deletions(-) diff --git a/shell/hush.c b/shell/hush.c index 503cb770b..6b3027771 100644 --- a/shell/hush.c +++ b/shell/hush.c @@ -3265,14 +3265,6 @@ static int done_word(o_string *word, struct parse_context *ctx) ) { p += 3; } - if (p == word->data || p[0] != '\0') { - /* saw no "$@", or not only "$@" but some - * real text is there too */ - /* insert "empty variable" reference, this makes - * e.g. "", $empty"" etc to not disappear */ - o_addchr(word, SPECIAL_VAR_SYMBOL); - o_addchr(word, SPECIAL_VAR_SYMBOL); - } } command->argv = add_string_to_strings(command->argv, xstrdup(word->data)); debug_print_strings("word appended to argv", command->argv); @@ -4516,20 +4508,30 @@ static struct pipe *parse_stream(char **pstring, break; case '\'': dest.has_quoted_part = 1; - while (1) { - ch = i_getch(input); - if (ch == EOF) { - syntax_error_unterm_ch('\''); - goto parse_error; + if (next == '\'' && !ctx.pending_redirect) { + insert_empty_quoted_str_marker: + nommu_addchr(&ctx.as_string, next); + i_getch(input); /* eat second ' */ + o_addchr(&dest, SPECIAL_VAR_SYMBOL); + o_addchr(&dest, SPECIAL_VAR_SYMBOL); + } else { + while (1) { + ch = i_getch(input); + if (ch == EOF) { + syntax_error_unterm_ch('\''); + goto parse_error; + } + nommu_addchr(&ctx.as_string, ch); + if (ch == '\'') + break; + o_addqchr(&dest, ch); } - nommu_addchr(&ctx.as_string, ch); - if (ch == '\'') - break; - o_addqchr(&dest, ch); } break; case '"': dest.has_quoted_part = 1; + if (next == '"' && !ctx.pending_redirect) + goto insert_empty_quoted_str_marker; if (dest.o_assignment == NOT_ASSIGNMENT) dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS; if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1)) @@ -4751,9 +4753,14 @@ static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len /* Store given string, finalizing the word and starting new one whenever * we encounter IFS char(s). This is used for expanding variable values. - * End-of-string does NOT finalize word: think about 'echo -$VAR-' */ -static int expand_on_ifs(o_string *output, int n, const char *str) + * End-of-string does NOT finalize word: think about 'echo -$VAR-'. + * Return in *ended_with_ifs: + * 1 - ended with IFS char, else 0 (this includes case of empty str). + */ +static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str) { + int last_is_ifs = 0; + while (1) { int word_len; @@ -4774,27 +4781,36 @@ static int expand_on_ifs(o_string *output, int n, const char *str) /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */ /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */ } + last_is_ifs = 0; str += word_len; if (!*str) /* EOL - do not finalize word */ break; - goto finalize; /* optimization (can just fall thru) */ } - /* Case "v=' a'; echo ''$v": we do need to finalize empty word */ + + /* We know str here points to at least one IFS char */ + last_is_ifs = 1; + str += strspn(str, G.ifs); /* skip IFS chars */ + if (!*str) /* EOL - do not finalize word */ + break; + + /* Start new word... but not always! */ + /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */ if (output->has_quoted_part /* Case "v=' a'; echo $v": * here nothing precedes the space in $v expansion, * therefore we should not finish the word - * (IOW: if there *is* word to finalize, only then do it) + * (IOW: if there *is* word to finalize, only then do it): */ - || (output->length && output->data[output->length - 1]) + || (n > 0 && output->data[output->length - 1]) ) { - finalize: o_addchr(output, '\0'); debug_print_list("expand_on_ifs", output, n); n = o_save_ptr(output, n); } - str += strspn(str, G.ifs); /* skip IFS chars */ } + + if (ended_with_ifs) + *ended_with_ifs = last_is_ifs; debug_print_list("expand_on_ifs[1]", output, n); return n; } @@ -5209,6 +5225,7 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg) * expansion of right-hand side of assignment == 1-element expand. */ char cant_be_null = 0; /* only bit 0x80 matters */ + int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */ char *p; debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg, @@ -5227,6 +5244,13 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg) #if ENABLE_SH_MATH_SUPPORT char arith_buf[sizeof(arith_t)*3 + 2]; #endif + + if (ended_in_ifs) { + o_addchr(output, '\0'); + n = o_save_ptr(output, n); + ended_in_ifs = 0; + } + o_addblock(output, arg, p - arg); debug_print_list("expand_vars_to_list[1]", output, n); arg = ++p; @@ -5255,7 +5279,7 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg) cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */ if (!(first_ch & 0x80)) { /* unquoted $* or $@ */ while (G.global_argv[i]) { - n = expand_on_ifs(output, n, G.global_argv[i]); + n = expand_on_ifs(NULL, output, n, G.global_argv[i]); debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1); if (G.global_argv[i++][0] && G.global_argv[i]) { /* this argv[] is not empty and not last: @@ -5332,7 +5356,7 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg) debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)); if (val && val[0]) { - n = expand_on_ifs(output, n, val); + n = expand_on_ifs(&ended_in_ifs, output, n, val); val = NULL; } } else { /* quoted $VAR, val will be appended below */ @@ -5361,6 +5385,10 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg) } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */ if (arg[0]) { + if (ended_in_ifs) { + o_addchr(output, '\0'); + n = o_save_ptr(output, n); + } debug_print_list("expand_vars_to_list[a]", output, n); /* this part is literal, and it was already pre-quoted * if needed (much earlier), do not use o_addQstr here! */ diff --git a/shell/hush_test/hush-parsing/starquoted2.right b/shell/hush_test/hush-parsing/starquoted2.right index e1562ed6d..1bff408ca 100644 --- a/shell/hush_test/hush-parsing/starquoted2.right +++ b/shell/hush_test/hush-parsing/starquoted2.right @@ -1,4 +1,7 @@ Should be printed +Would not be printed by bash +Would not be printed by bash +Would not be printed by bash Should be printed Empty: Empty: diff --git a/shell/hush_test/hush-parsing/starquoted2.tests b/shell/hush_test/hush-parsing/starquoted2.tests index f305c4cd9..7c5ff45b8 100755 --- a/shell/hush_test/hush-parsing/starquoted2.tests +++ b/shell/hush_test/hush-parsing/starquoted2.tests @@ -8,9 +8,9 @@ for a in "$@"; do echo Should not be printed; done # Yes, believe it or not, bash is mesmerized by "$@" and stops # treating "" as "this word cannot be expanded to nothing, # but must be at least null string". Now it can be expanded to nothing. -for a in "$@"""; do echo Should not be printed; done -for a in """$@"; do echo Should not be printed; done -for a in """$@"''"$@"''; do echo Should not be printed; done +for a in "$@"""; do echo Would not be printed by bash; done +for a in """$@"; do echo Would not be printed by bash; done +for a in """$@"''"$@"''; do echo Would not be printed by bash; done for a in ""; do echo Should be printed; done # Bug 207: "$@" expands to nothing, and we erroneously glob "%s\n" twice: -- 2.25.1