hush: disentangle keyword detection, no logic changes

function                                             old     new   delta
done_word                                            790     766     -24

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 27 insertions, 25 deletions

diff --git a/shell/hush.c b/shell/hush.c
index 00887d45f..f776a6468 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -3947,7 +3947,7 @@ static void debug_print_tree(struct pipe *pi, int lvl)
 # endif
 # if ENABLE_HUSH_CASE
                 [RES_CASE ] = "CASE" ,
-                [RES_CASE_IN ] = "CASE_IN" ,
+                [RES_CASE_IN] = "CASE_IN" ,
                 [RES_MATCH] = "MATCH",
                 [RES_CASE_BODY] = "CASE_BODY",
                 [RES_ESAC ] = "ESAC" ,
@@ -4289,11 +4289,22 @@ static const struct reserved_combo* reserved_word(struct parse_context *ctx)
 # endif
         const struct reserved_combo *r;
 
-        if (ctx->word.has_quoted_part)
-                return 0;
         r = match_reserved_word(ctx->word.data);
         if (!r)
                 return r; /* NULL */
+# if ENABLE_HUSH_CASE /* "case" syntax has a curveball */
+        if (ctx->ctx_res_w == RES_MATCH
+         && r->res != RES_ESAC
+        ) {
+                /* We are at WORD in ";; WORD" or "case .. in WORD".
+                 * Here, only "esac" is a keyword.
+                 * Else WORD is a case pattern, can be keyword-like:
+                 *  if) echo got_if;;
+                 * is allowed.
+                 */
+                return NULL;
+        }
+# endif
 
         debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
 # if ENABLE_HUSH_CASE
@@ -4309,7 +4320,7 @@ static const struct reserved_combo* reserved_word(struct parse_context *ctx)
                         return r;
                 }
 # endif
-                if (ctx->pipe->cmds != ctx->command /* bash disallows: nice | ! cat */
+                if (ctx->pipe->num_cmds != 0 /* bash disallows: nice | ! cat */
                 /* || ctx->pipe->pi_inverted - bash used to disallow "! ! true" bash 5.2.15 allows it */
                 ) {
                         syntax_error_unexpected_ch('!');
@@ -4443,36 +4454,26 @@ static int done_word(struct parse_context *ctx)
         }
 
 #if HAS_KEYWORDS
-# if ENABLE_HUSH_CASE
-        if (ctx->ctx_res_w == RES_MATCH
-         && (ctx->word.has_quoted_part
-            || strcmp(ctx->word.data, "esac") != 0
-            )
-        ) { /* ";; WORD" but not ";; esac" */
-                /* Do not match WORD as keyword:
-                 * the WORD is a case match, can be keyword-like:
-                 *  if) echo got_if;;
-                 * is allowed.
-                 */
-        } else
-# endif
 # if defined(CMD_TEST2_SINGLEWORD_NOGLOB)
         if (command->cmd_type == CMD_TEST2_SINGLEWORD_NOGLOB
          && !ctx->word.has_quoted_part
          && strcmp(ctx->word.data, "]]") == 0
         ) {
-                /* allow "[[ ]] >file" etc */
+                /* End test2-specific parsing rules */
+                /* Allow "[[ ]] >file" etc (> is a redirect symbol again) */
                 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
         } else
 # endif
-        if (!command->argv      /* if it's the first word of command... */
-         && !command->redirects /* no redirects yet... disallows: </dev/null if true; then... */
+        /* Is it a place where keyword can appear? */
+        if (!command->argv             /* if it's the first word of command... */
+         && !ctx->word.has_quoted_part /* ""WORD never matches any keywords */
+         && !command->redirects        /* no redirects yet... disallows: </dev/null if true; then... */
 # if ENABLE_HUSH_LOOPS
-         && ctx->ctx_res_w != RES_FOR /* not after FOR or IN */
+         && ctx->ctx_res_w != RES_FOR  /* not after "for" or "in" */
          && ctx->ctx_res_w != RES_IN
 # endif
 # if ENABLE_HUSH_CASE
-         && ctx->ctx_res_w != RES_CASE  /* not after CASE */
+         && ctx->ctx_res_w != RES_CASE /* not after "case" */
 # endif
         ) {
                 const struct reserved_combo *reserved;
@@ -4481,10 +4482,10 @@ static int done_word(struct parse_context *ctx)
                 if (reserved) {
 # if ENABLE_HUSH_LINENO_VAR
 /* Case:
- * "while ...; do
- *      cmd ..."
+ * while ...; do
+ *     CMD
  * If we don't close the pipe _now_, immediately after "do", lineno logic
- * sees "cmd" as starting at "do" - i.e., at the previous line.
+ * sees CMD as starting at "do" - i.e., at the previous line.
  */
                         if (0
                          IF_HUSH_IF(|| reserved->res == RES_THEN)
@@ -4502,6 +4503,7 @@ static int done_word(struct parse_context *ctx)
                 }
 # if defined(CMD_TEST2_SINGLEWORD_NOGLOB)
                 if (strcmp(ctx->word.data, "[[") == 0) {
+                        /* Inside [[ ]], parsing rules are different */
                         command->cmd_type = CMD_TEST2_SINGLEWORD_NOGLOB;
                 } else
 # endif