d029e8018
Denys Vlasenko
2025-08-14
Subject
hush: remove the is_blank dance
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shell/hush.c +58 -67shell/hush_test/hush-misc/case3.right +1 -2shell/hush_test/hush-misc/case3.tests +6 -7shell/hush_test/hush-misc/case4.right +2 -0shell/hush_test/hush-misc/case4.tests +8 -0
shell/hush.c+58 -67
| @@ -5601,7 +5601,6 @@ static struct pipe *parse_stream(char **pstring, | |
| heredoc_cnt = 0; | |
| while (1) { | |
| - | int is_blank; |
| int ch; | |
| int next; | |
| int redir_fd; | |
| @@ -5680,16 +5679,7 @@ static struct pipe *parse_stream(char **pstring, | |
| continue; /* get next char */ | |
| } | |
| - | next = '\0'; |
| - | is_blank = 1; |
| - | /* If '\n', must not peek (peeking past '\n' provokes line editing) */ |
| - | if (ch == '\n') |
| - | /* had to test for '\n' anyway, can also jump directly to newline handling */ |
| - | goto ch_is_newline; |
| - | next = i_peek_and_eat_bkslash_nl(input); |
| - | |
| - | is_blank = (ch == ' ' || ch == '\t'); |
| - | if (is_blank) { |
| + | if (ch == ' ' || ch == '\t') { |
| #if ENABLE_HUSH_LINENO_VAR | |
| /* "while ...; do<whitespace><newline> | |
| * CMD" | |
| @@ -5698,67 +5688,73 @@ static struct pipe *parse_stream(char **pstring, | |
| * Need to skip whitespace up to next newline (and eat it) | |
| * or not-whitespace (and do not eat it). | |
| */ | |
| - | do { |
| + | for (;;) { |
| next = i_peek(input); | |
| if (next != ' ' && next != '\t' && next != '\n') | |
| break; /* next char is not ws */ | |
| ch = i_getch(input); | |
| - | } while (ch != '\n'); |
| + | if (ch == '\n') |
| + | goto ch_is_newline; |
| + | } |
| #endif | |
| - | ch_is_newline: |
| if (done_word(&ctx)) | |
| goto parse_error_exitcode1; | |
| - | if (ch == '\n') { |
| - | /* Is this a case when newline is simply ignored? |
| - | * Some examples: |
| - | * "CMD | <newline> CMD ..." |
| - | * "case ... in <newline> PATTERN) ..." |
| + | continue; /* get next char */ |
| + | } |
| + | |
| + | if (ch == '\n') { |
| + | IF_HUSH_LINENO_VAR(ch_is_newline:) |
| + | if (done_word(&ctx)) |
| + | goto parse_error_exitcode1; |
| + | /* Is this a case when newline is simply ignored? |
| + | * Some examples: |
| + | * "CMD | <newline> CMD ..." |
| + | * "case ... in <newline> PATTERN) ..." |
| + | */ |
| + | if (IS_NULL_CMD(ctx.command) |
| + | && IS_NULL_WORD(ctx.word) |
| + | && heredoc_cnt == 0 |
| + | ) { |
| + | /* This newline can be ignored. But... |
| + | * Without check #1, interactive shell |
| + | * ignores even bare <newline>, |
| + | * and shows the continuation prompt: |
| + | * ps1$ <enter> |
| + | * ps2> _ <=== wrong, should be ps1 |
| + | * Without check #2, "CMD & <newline>" |
| + | * is similarly mistreated. |
| + | * (BTW, this makes "CMD & CMD" |
| + | * and "CMD && CMD" non-orthogonal. |
| + | * Really, ask yourself, why |
| + | * "CMD && <newline>" doesn't start |
| + | * CMD but waits for more input? |
| + | * The only reason is that it might be |
| + | * a "CMD1 && <nl> CMD2 &" construct: |
| + | * CMD1 may need to run in BG). |
| */ | |
| - | if (IS_NULL_CMD(ctx.command) |
| - | && IS_NULL_WORD(ctx.word) |
| - | && heredoc_cnt == 0 |
| + | pi = ctx.list_head; |
| + | if (pi->num_cmds != 0 /* check #1 */ |
| + | && pi->followup != PIPE_BG /* check #2 */ |
| ) { | |
| - | /* This newline can be ignored. But... |
| - | * Without check #1, interactive shell |
| - | * ignores even bare <newline>, |
| - | * and shows the continuation prompt: |
| - | * ps1$ <enter> |
| - | * ps2> _ <=== wrong, should be ps1 |
| - | * Without check #2, "CMD & <newline>" |
| - | * is similarly mistreated. |
| - | * (BTW, this makes "CMD & CMD" |
| - | * and "CMD && CMD" non-orthogonal. |
| - | * Really, ask yourself, why |
| - | * "CMD && <newline>" doesn't start |
| - | * CMD but waits for more input? |
| - | * The only reason is that it might be |
| - | * a "CMD1 && <nl> CMD2 &" construct: |
| - | * CMD1 may need to run in BG). |
| - | */ |
| - | pi = ctx.list_head; |
| - | if (pi->num_cmds != 0 /* check #1 */ |
| - | && pi->followup != PIPE_BG /* check #2 */ |
| - | ) { |
| - | continue; /* ignore newline */ |
| - | } |
| + | continue; /* ignore newline */ |
| } | |
| - | /* Treat newline as a command separator */ |
| - | done_pipe(&ctx, PIPE_SEQ); |
| - | debug_printf_heredoc("heredoc_cnt:%d\n", heredoc_cnt); |
| - | if (heredoc_cnt) { |
| - | heredoc_cnt = fetch_heredocs(&ctx.as_string, ctx.list_head, heredoc_cnt, input); |
| - | if (heredoc_cnt != 0) |
| - | goto parse_error_exitcode1; |
| - | } |
| - | ctx.is_assignment = MAYBE_ASSIGNMENT; |
| - | debug_printf_parse("ctx.is_assignment='%s'\n", assignment_flag[ctx.is_assignment]); |
| - | ch = ';'; |
| - | /* note: if (is_blank) continue; |
| - | * will still trigger for us */ |
| - | } /* if ch == '\n */ |
| + | } |
| + | /* Treat newline as a command separator */ |
| + | done_pipe(&ctx, PIPE_SEQ); |
| + | debug_printf_heredoc("heredoc_cnt:%d\n", heredoc_cnt); |
| + | if (heredoc_cnt) { |
| + | heredoc_cnt = fetch_heredocs(&ctx.as_string, ctx.list_head, heredoc_cnt, input); |
| + | if (heredoc_cnt != 0) |
| + | goto parse_error_exitcode1; |
| + | } |
| + | ctx.is_assignment = MAYBE_ASSIGNMENT; |
| + | debug_printf_parse("ctx.is_assignment='%s'\n", assignment_flag[ctx.is_assignment]); |
| + | next = '\0'; |
| + | ch = ';'; |
| } else { | |
| const char *is_special; | |
| + | next = i_peek_and_eat_bkslash_nl(input); |
| is_special = "{}<>&|();#" /* special outside of "str" */ | |
| "$\"" IF_HUSH_TICK("`") /* always special */ | |
| SPECIAL_VAR_SYMBOL_STR; | |
| @@ -5782,8 +5778,7 @@ static struct pipe *parse_stream(char **pstring, | |
| /* They are not special, skip "{}" */ | |
| is_special += 2; | |
| } | |
| - | is_special = strchr(is_special, ch); |
| - | if (!is_special) { /* ordinary char */ |
| + | if (!strchr(is_special, ch)) { /* ordinary char? */ |
| ordinary_char: | |
| o_addQchr(&ctx.word, ch); | |
| if ((ctx.is_assignment == MAYBE_ASSIGNMENT | |
| @@ -5794,7 +5789,7 @@ static struct pipe *parse_stream(char **pstring, | |
| ctx.is_assignment = DEFINITELY_ASSIGNMENT; | |
| debug_printf_parse("ctx.is_assignment='%s'\n", assignment_flag[ctx.is_assignment]); | |
| } | |
| - | continue; |
| + | continue; /* get next char */ |
| } | |
| } | |
| @@ -5874,9 +5869,6 @@ static struct pipe *parse_stream(char **pstring, | |
| } | |
| } | |
| - | if (is_blank) /* space, tab or newline? */ |
| - | continue; |
| - | |
| /* Catch <, > before deciding whether this word is | |
| * an assignment. a=1 2>z b=2: b=2 is still assignment */ | |
| switch (ch) { | |
| @@ -6022,8 +6014,7 @@ static struct pipe *parse_stream(char **pstring, | |
| done_pipe(&ctx, PIPE_SEQ); | |
| #if ENABLE_HUSH_CASE | |
| if (ctx.ctx_res_w == RES_CASE_BODY | |
| - | && !is_blank /* is it really actual semicolon? */ |
| - | && i_peek_and_eat_bkslash_nl(input) == ';' /* and next char is ';' too? */ |
| + | && next == ';' /* and next char is ';' too? */ |
| ) { | |
| ch = i_getch(input); | |
| nommu_addchr(&ctx.as_string, ch); | |
shell/hush_test/hush-misc/case3.right+1 -2
| @@ -1,2 +1 @@ | |
| - | Keyword-like word may be in pattern |
| - | Ok:0 |
| + | hush: syntax error: unexpected ) |
shell/hush_test/hush-misc/case3.tests+6 -7
| @@ -1,8 +1,7 @@ | |
| - | if=if |
| - | case if in |
| - | if) echo "Keyword-like word may be in pattern";; |
| - | fi) echo "Not reached";; |
| - | # esac) echo "Not reached";; # not accepted by bash 5.2.15 |
| - | do) echo "Not reached" |
| + | # had a parser bug which incorrectly detected ";;" |
| + | case w in |
| + | a) true |
| + | ; |
| + | b);; |
| esac | |
| - | echo Ok:$? |
| + | echo Should not be reached |
shell/hush_test/hush-misc/case4.right+2 -0
| @@ -0,0 +1,2 @@ | |
| + | Keyword-like word may be in pattern |
| + | Ok:0 |
shell/hush_test/hush-misc/case4.tests+8 -0
| @@ -0,0 +1,8 @@ | |
| + | if=if |
| + | case if in |
| + | if) echo "Keyword-like word may be in pattern";; |
| + | fi) echo "Not reached";; |
| + | # esac) echo "Not reached";; # not accepted by bash 5.2.15 |
| + | do) echo "Not reached" |
| + | esac |
| + | echo Ok:$? |