ash: handle "A=1 A=2 B=$A; echo $B". closes bug 947.

diff --git a/shell/ash.c b/shell/ash.c
index 10eb90d30e103d52658f643924090dacec09f83c..4f9caa43496caf001048adf5cfa999cb83b361a5 100644 (file)
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -42,19 +42,18 @@
  * a quit signal will generate a core dump.
  */
 #define DEBUG 0
-#define IFS_BROKEN
 #define PROFILE 0
-#if ENABLE_ASH_JOB_CONTROL
-#define JOBS 1
-#else
-#define JOBS 0
-#endif
+
+#define IFS_BROKEN
+
+#define JOBS ENABLE_ASH_JOB_CONTROL
 
 #if DEBUG
 #ifndef _GNU_SOURCE
 #define _GNU_SOURCE
 #endif
 #endif
+
 #include "busybox.h" /* for applet_names */
 #include <paths.h>
 #include <setjmp.h>
@@ -5501,15 +5500,19 @@ expari(int quotes)
 #endif
 
 /* argstr needs it */
-static char *evalvar(char *p, int flag);
+static char *evalvar(char *p, int flag, struct strlist *var_str_list);
 
 /*
  * Perform variable and command substitution.  If EXP_FULL is set, output CTLESC
  * characters to allow for further processing.  Otherwise treat
  * $@ like $* since no splitting will be performed.
+ *
+ * var_str_list (can be NULL) is a list of "VAR=val" strings which take precedence
+ * over shell varables. Needed for "A=a B=$A; echo $B" case - we use it
+ * for correct expansion of "B=$A" word.
  */
 static void
-argstr(char *p, int flag)
+argstr(char *p, int flag, struct strlist *var_str_list)
 {
        static const char spclchars[] ALIGN1 = {
                '=',
@@ -5611,7 +5614,7 @@ argstr(char *p, int flag)
                                        p[5] == CTLQUOTEMARK
                                ))
                        ) {
-                               p = evalvar(p + 1, flag) + 1;
+                               p = evalvar(p + 1, flag, /* var_str_list: */ NULL) + 1;
                                goto start;
                        }
                        inquotes = !inquotes;
@@ -5627,7 +5630,7 @@ argstr(char *p, int flag)
                        length++;
                        goto addquote;
                case CTLVAR:
-                       p = evalvar(p, flag);
+                       p = evalvar(p, flag, var_str_list);
                        goto start;
                case CTLBACKQ:
                        c = 0;
@@ -5731,7 +5734,8 @@ varunset(const char *end, const char *var, const char *umsg, int varflags)
 }
 
 static const char *
-subevalvar(char *p, char *str, int strloc, int subtype, int startloc, int varflags, int quotes)
+subevalvar(char *p, char *str, int strloc, int subtype,
+               int startloc, int varflags, int quotes, struct strlist *var_str_list)
 {
        char *startp;
        char *loc;
@@ -5743,7 +5747,8 @@ subevalvar(char *p, char *str, int strloc, int subtype, int startloc, int varfla
        char *(*scan)(char *, char *, char *, char *, int , int);
 
        herefd = -1;
-       argstr(p, subtype != VSASSIGN && subtype != VSQUESTION ? EXP_CASE : 0);
+       argstr(p, (subtype != VSASSIGN && subtype != VSQUESTION) ? EXP_CASE : 0,
+                       var_str_list);
        STPUTC('\0', expdest);
        herefd = saveherefd;
        argbackq = saveargbackq;
@@ -5802,7 +5807,7 @@ subevalvar(char *p, char *str, int strloc, int subtype, int startloc, int varfla
  * Add the value of a specialized variable to the stack string.
  */
 static ssize_t
-varvalue(char *name, int varflags, int flags)
+varvalue(char *name, int varflags, int flags, struct strlist *var_str_list)
 {
        int num;
        char *p;
@@ -5899,6 +5904,30 @@ varvalue(char *name, int varflags, int flags)
                p = num ? shellparam.p[num - 1] : arg0;
                goto value;
        default:
+               /* NB: name has form "VAR=..." */
+
+               /* "A=a B=$A" case: var_str_list is a list of "A=a" strings
+                * which should be considered before we check variables. */
+               if (var_str_list) {
+                       unsigned name_len = (strchrnul(name, '=') - name) + 1;
+                       p = NULL;
+                       do {
+                               char *str = var_str_list->text;
+                               char *eq = strchr(str, '=');
+                               if (!eq) /* stop at first non-assignment */
+                                       break;
+                               eq++;
+                               if (name_len == (eq - str)
+                                && strncmp(str, name, name_len) == 0) {
+                                       p = eq;
+                                       /* goto value; - WRONG! */
+                                       /* think "A=1 A=2 B=$A" */
+                               }
+                               var_str_list = var_str_list->next;
+                       } while (var_str_list);
+                       if (p)
+                               goto value;
+               }
                p = lookupvar(name);
  value:
                if (!p)
@@ -5920,20 +5949,17 @@ varvalue(char *name, int varflags, int flags)
  * input string.
  */
 static char *
-evalvar(char *p, int flag)
+evalvar(char *p, int flag, struct strlist *var_str_list)
 {
-       int subtype;
-       int varflags;
+       char varflags;
+       char subtype;
+       char quoted;
+       char easy;
        char *var;
        int patloc;
-       int c;
        int startloc;
        ssize_t varlen;
-       int easy;
-       int quotes;
-       int quoted;
 
-       quotes = flag & (EXP_FULL | EXP_CASE);
        varflags = *p++;
        subtype = varflags & VSTYPE;
        quoted = varflags & VSQUOTE;
@@ -5943,7 +5969,7 @@ evalvar(char *p, int flag)
        p = strchr(p, '=') + 1;
 
  again:
-       varlen = varvalue(var, varflags, flag);
+       varlen = varvalue(var, varflags, flag, var_str_list);
        if (varflags & VSNUL)
                varlen--;
 
@@ -5957,7 +5983,8 @@ evalvar(char *p, int flag)
                if (varlen < 0) {
                        argstr(
                                p, flag | EXP_TILDE |
-                                       (quoted ?  EXP_QWORD : EXP_WORD)
+                                       (quoted ?  EXP_QWORD : EXP_WORD),
+                               var_str_list
                        );
                        goto end;
                }
@@ -5968,7 +5995,11 @@ evalvar(char *p, int flag)
 
        if (subtype == VSASSIGN || subtype == VSQUESTION) {
                if (varlen < 0) {
-                       if (subevalvar(p, var, 0, subtype, startloc, varflags, 0)) {
+                       if (subevalvar(p, var, /* strloc: */ 0,
+                                       subtype, startloc, varflags,
+                                       /* quotes: */ 0,
+                                       var_str_list)
+                       ) {
                                varflags &= ~VSNUL;
                                /*
                                 * Remove any recorded regions beyond
@@ -5993,10 +6024,8 @@ evalvar(char *p, int flag)
        }
 
        if (subtype == VSNORMAL) {
-               if (!easy)
-                       goto end;
- record:
-               recordregion(startloc, expdest - (char *)stackblock(), quoted);
+               if (easy)
+                       goto record;
                goto end;
        }
 
@@ -6019,8 +6048,11 @@ evalvar(char *p, int flag)
                 */
                STPUTC('\0', expdest);
                patloc = expdest - (char *)stackblock();
-               if (subevalvar(p, NULL, patloc, subtype,
-                               startloc, varflags, quotes) == 0) {
+               if (0 == subevalvar(p, /* str: */ NULL, patloc, subtype,
+                               startloc, varflags,
+                               /* quotes: */ flag & (EXP_FULL | EXP_CASE),
+                               var_str_list)
+               ) {
                        int amount = expdest - (
                                (char *)stackblock() + patloc - 1
                        );
@@ -6028,14 +6060,15 @@ evalvar(char *p, int flag)
                }
                /* Remove any recorded regions beyond start of variable */
                removerecordregions(startloc);
-               goto record;
+ record:
+               recordregion(startloc, expdest - (char *)stackblock(), quoted);
        }
 
  end:
        if (subtype != VSNORMAL) {      /* skip to end of alternative */
                int nesting = 1;
                for (;;) {
-                       c = *p++;
+                       char c = *p++;
                        if (c == CTLESC)
                                p++;
                        else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) {
@@ -6420,7 +6453,8 @@ expandarg(union node *arg, struct arglist *arglist, int flag)
        STARTSTACKSTR(expdest);
        ifsfirst.next = NULL;
        ifslastp = NULL;
-       argstr(arg->narg.text, flag);
+       argstr(arg->narg.text, flag,
+                       /* var_str_list: */ arglist ? arglist->list : NULL);
        p = _STPUTC('\0', expdest);
        expdest = p - 1;
        if (arglist == NULL) {
@@ -6486,7 +6520,8 @@ casematch(union node *pattern, char *val)
        argbackq = pattern->narg.backquote;
        STARTSTACKSTR(expdest);
        ifslastp = NULL;
-       argstr(pattern->narg.text, EXP_TILDE | EXP_CASE);
+       argstr(pattern->narg.text, EXP_TILDE | EXP_CASE,
+                       /* var_str_list: */ NULL);
        STACKSTRNUL(expdest);
        result = patmatch(stackblock(), val);
        popstackmark(&smark);
@@ -8249,8 +8284,8 @@ bltincmd(int argc, char **argv)
 static void
 evalcommand(union node *cmd, int flags)
 {
-       static const struct builtincmd bltin = {
-               "\0\0", bltincmd
+       static const struct builtincmd null_bltin = {
+               "\0\0", bltincmd /* why three NULs? */
        };
        struct stackmark smark;
        union node *argp;
@@ -8276,7 +8311,7 @@ evalcommand(union node *cmd, int flags)
        back_exitstatus = 0;
 
        cmdentry.cmdtype = CMDBUILTIN;
-       cmdentry.u.cmd = &bltin;
+       cmdentry.u.cmd = &null_bltin;
        varlist.lastp = &varlist.list;
        *varlist.lastp = NULL;
        arglist.lastp = &arglist.list;
@@ -8352,7 +8387,7 @@ evalcommand(union node *cmd, int flags)
                        }
                        sp = arglist.list;
                }
-               full_write(preverrout_fd, "\n", 1);
+               safe_write(preverrout_fd, "\n", 1);
        }
 
        cmd_is_exec = 0;

diff --git a/shell/ash_test/ash-vars/var1.right b/shell/ash_test/ash-vars/var1.right
new file mode 100644 (file)
index 0000000..2a01291
--- /dev/null
+++ b/shell/ash_test/ash-vars/var1.right
@@ -0,0 +1,6 @@
+a=a A=a
+a=a A=a
+a= A=
+a= A=
+a=a A=a
+a=a A=a

diff --git a/shell/ash_test/ash-vars/var1.tests b/shell/ash_test/ash-vars/var1.tests
new file mode 100755 (executable)
index 0000000..802e489
--- /dev/null
+++ b/shell/ash_test/ash-vars/var1.tests
@@ -0,0 +1,14 @@
+# check that first assignment has proper effect on second one
+
+(
+a=a A=$a
+echo a=$a A=$A
+)
+(a=a A=$a; echo a=$a A=$A)
+(a=a A=$a echo a=$a A=$A)
+(a=a A=$a /bin/echo a=$a A=$A)
+
+f() { echo a=$a A=$A; }
+
+(a=a A=$a f)
+(a=a A=$a; f)

diff --git a/shell/ash_test/ash-vars/var2.right b/shell/ash_test/ash-vars/var2.right
new file mode 100644 (file)
index 0000000..8fed138
--- /dev/null
+++ b/shell/ash_test/ash-vars/var2.right
@@ -0,0 +1 @@
+bus/usb/1/2

diff --git a/shell/ash_test/ash-vars/var2.tests b/shell/ash_test/ash-vars/var2.tests
new file mode 100755 (executable)
index 0000000..07feaeb
--- /dev/null
+++ b/shell/ash_test/ash-vars/var2.tests
@@ -0,0 +1 @@
+X=usbdev1.2 X=${X#usbdev} B=${X%%.*} D=${X#*.}; echo bus/usb/$B/$D

diff --git a/shell/ash_test/run-all b/shell/ash_test/run-all
index 416900aa203bfe79e21708fe4b59032d860ce339..e023338880b531ea710a192b55355e1c579e1c9a 100755 (executable)
--- a/shell/ash_test/run-all
+++ b/shell/ash_test/run-all
@@ -17,6 +17,7 @@ export THIS_SH
 do_test()
 {
     test -d "$1" || return 0
+    echo do_test "$1"
     (
     cd "$1" || { echo "cannot cd $1!"; exit 1; }
     for x in run-*; do
@@ -53,7 +54,6 @@ if [ $# -lt 1 ]; then
     modules=`ls -d ash-*`
 
     for module in $modules; do
-       echo do_test $module
        do_test $module
     done
 else