ash: introduce bash-like $FUNCNAME

Patch adapted from Roberto A. Foglietta <roberto.foglietta@gmail.com>
work.

function                                             old     new   delta
lookupvar                                            106     150     +44
evalfun                                              369     408     +39
ash_main                                            1218    1242     +24
varinit_data                                         156     168     +12
.rodata                                           104162  104172     +10
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 5/0 up/down: 129/0)             Total: 129 bytes

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

1 files changed, 24 insertions, 3 deletions

diff --git a/shell/ash.c b/shell/ash.c
index b12b859d5..4bc4f55d0 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -2158,6 +2158,7 @@ static const struct {
         { VSTRFIXED|VTEXTFIXED       , defoptindvar, getoptsreset    },
 #endif
         { VSTRFIXED|VTEXTFIXED       , NULL /* inited to linenovar */, NULL },
+        { VSTRFIXED|VTEXTFIXED       , NULL /* inited to funcnamevar */, NULL },
 #if ENABLE_ASH_RANDOM_SUPPORT
         { VSTRFIXED|VTEXTFIXED|VUNSET|VDYNAMIC, "RANDOM", change_random },
 #endif
@@ -2184,6 +2185,8 @@ struct globals_var {
         struct var varinit[ARRAY_SIZE(varinit_data)];
         int lineno;
         char linenovar[sizeof("LINENO=") + sizeof(int)*3];
+        char funcnamevar[sizeof("FUNCNAME=") + 64];
+        char *funcname;
         unsigned trap_depth;
         bool in_trap_ERR; /* ERR cannot recurse, no need to be a counter */
 };
@@ -2196,6 +2199,8 @@ extern struct globals_var *BB_GLOBAL_CONST ash_ptr_to_globals_var;
 #define varinit       (G_var.varinit      )
 #define lineno        (G_var.lineno       )
 #define linenovar     (G_var.linenovar    )
+#define funcnamevar   (G_var.funcnamevar  )
+#define funcname      (G_var.funcname     )
 #define trap_depth    (G_var.trap_depth   )
 #define in_trap_ERR   (G_var.in_trap_ERR  )
 #define vifs      varinit[0]
@@ -2213,13 +2218,14 @@ extern struct globals_var *BB_GLOBAL_CONST ash_ptr_to_globals_var;
 #endif
 #define VAR_OFFSET2 (VAR_OFFSET1 + ENABLE_ASH_GETOPTS)
 #define vlineno   varinit[VAR_OFFSET2 + 5]
+#define vfuncname varinit[VAR_OFFSET2 + 6]
 #if ENABLE_ASH_RANDOM_SUPPORT
-# define vrandom  varinit[VAR_OFFSET2 + 6]
+# define vrandom  varinit[VAR_OFFSET2 + 7]
 #endif
 #define VAR_OFFSET3 (VAR_OFFSET2 + ENABLE_ASH_RANDOM_SUPPORT)
 #if BASH_EPOCH_VARS
-# define vepochs  varinit[VAR_OFFSET3 + 6]
-# define vepochr  varinit[VAR_OFFSET3 + 7]
+# define vepochs  varinit[VAR_OFFSET3 + 7]
+# define vepochr  varinit[VAR_OFFSET3 + 8]
 #endif
 #define INIT_G_var() do { \
         unsigned i; \
@@ -2232,6 +2238,8 @@ extern struct globals_var *BB_GLOBAL_CONST ash_ptr_to_globals_var;
         } \
         strcpy(linenovar, "LINENO="); \
         vlineno.var_text = linenovar; \
+        strcpy(funcnamevar, "FUNCNAME="); \
+        vfuncname.var_text = funcnamevar; \
 } while (0)
 
 /*
@@ -2371,6 +2379,9 @@ lookupvar(const char *name)
                 if (!(v->flags & VUNSET)) {
                         if (v->var_text == linenovar) {
                                 fmtstr(linenovar+7, sizeof(linenovar)-7, "%d", lineno);
+                        } else
+                        if (v->var_text == funcnamevar) {
+                                safe_strncpy(funcnamevar+9, funcname ? funcname : "", sizeof(funcnamevar)-9);
                         }
                         return var_end(v->var_text);
                 }
@@ -9875,6 +9886,7 @@ evalfun(struct funcnode *func, int argc, char **argv, int flags)
         int e;
         int savelineno;
         int savefuncline;
+        char *savefuncname;
         char *savetrap = NULL;
 
         if (!Eflag) {
@@ -9884,6 +9896,7 @@ evalfun(struct funcnode *func, int argc, char **argv, int flags)
         savelineno = lineno;
         saveparam = shellparam;
         savefuncline = funcline;
+        savefuncname = funcname;
         savehandler = exception_handler;
         e = setjmp(jmploc.loc);
         if (e) {
@@ -9893,6 +9906,7 @@ evalfun(struct funcnode *func, int argc, char **argv, int flags)
         exception_handler = &jmploc;
         shellparam.malloced = 0;
         func->count++;
+        funcname = func->n.ndefun.text;
         funcline = func->n.ndefun.linno;
         INT_ON;
         shellparam.nparam = argc - 1;
@@ -9904,6 +9918,7 @@ evalfun(struct funcnode *func, int argc, char **argv, int flags)
         evaltree(func->n.ndefun.body, flags & EV_TESTED);
  funcdone:
         INT_OFF;
+        funcname = savefuncname;
         if (savetrap) {
                 if (!trap[NTRAP_ERR])
                         trap[NTRAP_ERR] = savetrap;
@@ -13639,6 +13654,12 @@ exitcmd(int argc UNUSED_PARAM, char **argv)
         if (argv[1])
                 savestatus = number(argv[1]);
 
+//TODO: this script
+// trap 'echo trap:$FUNCNAME' EXIT
+// f() { exit; }
+// f
+//prints "trap:f" in bash. We can call exitshell() here to achieve this.
+//For now, keeping dash code:
         raise_exception(EXEXIT);
         /* NOTREACHED */
 }