ash: fix var_bash5.tests - ${VAR/pattern/repl} construct

function                                             old     new   delta
subevalvar                                          1198    1279     +81
rmescapes                                            308     330     +22
preglob                                                8      10      +2
parsefname                                           152     154      +2
expandarg                                            973     975      +2
argstr                                              1144    1146      +2
mklocal                                              290     288      -2
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 6/1 up/down: 111/-2)            Total: 109 bytes

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

diff --git a/shell/ash.c b/shell/ash.c
index b73a79975de4f6c561738743b86ea062afd3b0e5..5381f34eb1c67c5f04a50eab1b5682258be85c56 100644 (file)
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -5811,7 +5811,6 @@ ash_arith(const char *s)
 #define RMESCAPE_GLOB   0x2     /* Add backslashes for glob */
 #define RMESCAPE_GROW   0x8     /* Grow strings instead of stalloc */
 #define RMESCAPE_HEAP   0x10    /* Malloc strings instead of stalloc */
-#define RMESCAPE_SLASH  0x20    /* Stop globbing after slash */
 
 /* Add CTLESC when necessary. */
 #define QUOTES_ESC     (EXP_FULL | EXP_CASE | EXP_QPAT)
@@ -5992,8 +5991,12 @@ esclen(const char *start, const char *p)
 /*
  * Remove any CTLESC characters from a string.
  */
+#if !BASH_PATTERN_SUBST
+#define rmescapes(str, flag, slash_position) \
+       rmescapes(str, flag)
+#endif
 static char *
-rmescapes(char *str, int flag)
+rmescapes(char *str, int flag, int *slash_position)
 {
        static const char qchars[] ALIGN1 = {
                IF_BASH_PATTERN_SUBST('/',) CTLESC, CTLQUOTEMARK, '\0' };
@@ -6002,9 +6005,8 @@ rmescapes(char *str, int flag)
        unsigned inquotes;
        unsigned protect_against_glob;
        unsigned globbing;
-       IF_BASH_PATTERN_SUBST(unsigned slash = flag & RMESCAPE_SLASH;)
 
-       p = strpbrk(str, qchars IF_BASH_PATTERN_SUBST(+ !slash));
+       p = strpbrk(str, qchars IF_BASH_PATTERN_SUBST(+ !slash_position));
        if (!p)
                return str;
 
@@ -6084,10 +6086,11 @@ rmescapes(char *str, int flag)
                        goto copy;
                }
 #if BASH_PATTERN_SUBST
-               else if (*p == '/' && slash) {
-                       /* stop handling globbing and mark location of slash */
-                       globbing = slash = 0;
-                       *p = CTLESC;
+               else if (slash_position && p == str + *slash_position) {
+                       /* stop handling globbing */
+                       globbing = 0;
+                       *slash_position = q - r;
+                       slash_position = NULL;
                }
 #endif
                protect_against_glob = globbing;
@@ -6111,7 +6114,7 @@ rmescapes(char *str, int flag)
 static char *
 preglob(const char *pattern, int flag)
 {
-       return rmescapes((char *)pattern, flag | RMESCAPE_GLOB);
+       return rmescapes((char *)pattern, flag | RMESCAPE_GLOB, NULL);
 }
 
 /*
@@ -6454,7 +6457,7 @@ expari(int flag)
        expdest = p;
 
        if (flag & QUOTES_ESC)
-               rmescapes(p + 1, 0);
+               rmescapes(p + 1, 0, NULL);
 
        len = cvtnum(ash_arith(p + 1));
 
@@ -6742,20 +6745,57 @@ subevalvar(char *p, char *varname, int strloc, int subtype,
        char *rmesc, *rmescend;
        char *str;
        int amount, resetloc;
+       int argstr_flags;
        IF_BASH_PATTERN_SUBST(int workloc;)
-       IF_BASH_PATTERN_SUBST(char *repl = NULL;)
+       IF_BASH_PATTERN_SUBST(int slash_pos;)
+       IF_BASH_PATTERN_SUBST(char *repl;)
        int zero;
        char *(*scan)(char*, char*, char*, char*, int, int);
 
        //bb_error_msg("subevalvar(p:'%s',varname:'%s',strloc:%d,subtype:%d,startloc:%d,varflags:%x,quotes:%d)",
        //              p, varname, strloc, subtype, startloc, varflags, quotes);
 
-       argstr(p, EXP_TILDE | (subtype != VSASSIGN && subtype != VSQUESTION ?
-                       (flag & (EXP_QUOTED | EXP_QPAT) ? EXP_QPAT : EXP_CASE) : 0)
-       );
+#if BASH_PATTERN_SUBST
+       repl = NULL;
+       if (subtype == VSREPLACE || subtype == VSREPLACEALL) {
+               /* Find '/' and replace with NUL */
+               repl = p;
+               for (;;) {
+                       /* Handle escaped slashes, e.g. "${v/\//_}" (they are CTLESC'ed by this point) */
+                       if (*repl == '\0') {
+                               repl = NULL;
+                               break;
+                       }
+                       if (*repl == '/') {
+                               *repl = '\0';
+                               break;
+                       }
+                       if ((unsigned char)*repl == CTLESC
+                        && repl[1]
+                       ) {
+                               repl++;
+                       }
+                       repl++;
+               }
+       }
+#endif
+       argstr_flags = EXP_TILDE;
+       if (subtype != VSASSIGN && subtype != VSQUESTION)
+               argstr_flags |= (flag & (EXP_QUOTED | EXP_QPAT) ? EXP_QPAT : EXP_CASE);
+       argstr(p, argstr_flags);
+#if BASH_PATTERN_SUBST
+       slash_pos = -1;
+       if (repl) {
+               slash_pos = expdest - ((char *)stackblock() + strloc);
+               STPUTC('/', expdest);
+               argstr(repl + 1, argstr_flags);
+               *repl = '/';
+       }
+#endif
        STPUTC('\0', expdest);
        argbackq = saveargbackq;
        startp = (char *)stackblock() + startloc;
+       //bb_error_msg("str1:'%s'", (char *)stackblock() + strloc);
 
        switch (subtype) {
        case VSASSIGN:
@@ -6853,6 +6893,8 @@ subevalvar(char *p, char *varname, int strloc, int subtype,
        resetloc = expdest - (char *)stackblock();
 
 #if BASH_PATTERN_SUBST
+       repl = NULL;
+
        /* We'll comeback here if we grow the stack while handling
         * a VSREPLACE or VSREPLACEALL, since our pointers into the
         * stack will need rebasing, and we'll need to remove our work
@@ -6867,8 +6909,10 @@ subevalvar(char *p, char *varname, int strloc, int subtype,
 
        rmesc = startp;
        rmescend = (char *)stackblock() + strloc;
+       //bb_error_msg("str7:'%s'", rmescend);
        if (quotes) {
-               rmesc = rmescapes(startp, RMESCAPE_ALLOC | RMESCAPE_GROW);
+//TODO: how to handle slash_pos here if string changes (shortens?)
+               rmesc = rmescapes(startp, RMESCAPE_ALLOC | RMESCAPE_GROW, NULL);
                if (rmesc != startp) {
                        rmescend = expdest;
                        startp = (char *)stackblock() + startloc;
@@ -6881,12 +6925,13 @@ subevalvar(char *p, char *varname, int strloc, int subtype,
         * The result is a_\_z_c (not a\_\_z_c)!
         *
         * The search pattern and replace string treat backslashes differently!
-        * RMESCAPE_SLASH causes preglob to work differently on the pattern
+        * "&slash_pos" causes rmescapes() to work differently on the pattern
         * and string.  It's only used on the first call.
         */
-       preglob(str, IF_BASH_PATTERN_SUBST(
-               (subtype == VSREPLACE || subtype == VSREPLACEALL) && !repl ?
-                       RMESCAPE_SLASH : ) 0);
+       //bb_error_msg("str8:'%s' slash_pos:%d", str, slash_pos);
+       rmescapes(str, RMESCAPE_GLOB,
+               repl ? NULL : (slash_pos < 0 ? NULL : &slash_pos)
+       );
 
 #if BASH_PATTERN_SUBST
        workloc = expdest - (char *)stackblock();
@@ -6895,11 +6940,13 @@ subevalvar(char *p, char *varname, int strloc, int subtype,
                char *idx, *end;
 
                if (!repl) {
-                       repl = strchr(str, CTLESC);
-                       if (repl)
+                       //bb_error_msg("str9:'%s' slash_pos:%d", str, slash_pos);
+                       if (slash_pos >= 0) {
+                               repl = str + slash_pos;
                                *repl++ = '\0';
-                       else
+                       } else {
                                repl = nullstr;
+                       }
                }
                //bb_error_msg("str:'%s' repl:'%s'", str, repl);
 
@@ -7419,7 +7466,7 @@ expandmeta(struct strlist *str /*, int flag*/)
                        INT_ON;
  nometa:
                        *exparg.lastp = str;
-                       rmescapes(str->text, 0);
+                       rmescapes(str->text, 0, NULL);
                        exparg.lastp = &str->next;
                        break;
                default:        /* GLOB_NOSPACE */
@@ -7648,7 +7695,7 @@ expandmeta(struct strlist *str /*, int flag*/)
                         */
  nometa:
                        *exparg.lastp = str;
-                       rmescapes(str->text, 0);
+                       rmescapes(str->text, 0, NULL);
                        exparg.lastp = &str->next;
                } else {
                        *exparg.lastp = NULL;
@@ -11328,7 +11375,7 @@ parsefname(void)
                if (quoteflag == 0)
                        n->type = NXHERE;
                TRACE(("Here document %d\n", n->type));
-               rmescapes(wordtext, 0);
+               rmescapes(wordtext, 0, NULL);
                here->eofmark = wordtext;
                here->next = NULL;
                if (heredoclist == NULL)