Re: Detect if a script is being sourced vs executed

[Peter Stephenson <p.w.stephenson@xxxxxxxxxxxx>]

On Sat, 13 Sep 2014 09:01:21 +0100
Peter Stephenson <p.w.stephenson@xxxxxxxxxxxx> wrote:
> On 13/09/2014, Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx> wrote:
> > On Sep 12,  8:05pm, Peter Stephenson wrote:
> > }
> > } I was surprised to find the zsh/parameter modules series of array
> > } parameters that allow you to trace back the functions, sourced files,
> > } etc. being executed don't give this information, which is present
> > } internally.  This adds $functypestack to do this.
> >
> > Is this in some way NOT redundant with $zsh_eval_context ?  Other than
> > apparently being in the reverse order?
> 
> You're right, I was looking in the wrong place.  It can
> be replaced simply by a cross-reference.

They also don't actually quite correspond -- you can get extra entries
in zsh_eval_context since it intercepts the lowest level of code
execution while the funcstack stuff is done for each applicable layer
separately.  So there's potentially some use for functypestack ---
however, it's not needed for the purpose here, where
$zsh_eval_context[-1] is good enough (it'll be either "toplevel" or
"file").

diff --git a/Doc/Zsh/mod_parameter.yo b/Doc/Zsh/mod_parameter.yo
index c157160..7886d0e 100644
--- a/Doc/Zsh/mod_parameter.yo
+++ b/Doc/Zsh/mod_parameter.yo
@@ -201,10 +201,7 @@ The format of each element is var(filename)tt(:)var(lineno).
 For functions autoloaded from a file in native zsh format, where only the
 body of the function occurs in the file, or for files that have been
 executed by the tt(source) or `tt(.)' builtins, the trace information is
-shown as var(filename)tt(:)var(0), since the entire file is the
-definition.
-
-The most recent call is the first element in the array.
+shown as var(filename)tt(:)var(0), since the entire file is the definition.
 
 Most users will be interested in the information in the
 tt(funcfiletrace) array instead.
@@ -215,6 +212,14 @@ This array contains the names of the functions, sourced files,
 and (if tt(EVAL_LINENO) is set) tt(eval) commands. currently being
 executed. The first element is the name of the function using the
 parameter.
+
+The standard shell array tt(zsh_eval_context) can be used to
+determine the type of shell construct being executed at each depth:
+note, however, that is in the opposite order, with the most recent
+item last, and it is more detailed, for example including an
+entry for tt(toplevel), the main shell code being executed
+either interactively or from a script, which is not present
+in tt($funcstack).
 )
 vindex(functrace)
 item(tt(functrace))(
@@ -224,13 +229,4 @@ The format of each element is var(name)tt(:)var(lineno).
 Callers are also shown for sourced files; the caller is the point
 where the tt(source) or `tt(.)' command was executed.
 )
-vindex(functypestack)
-item(tt(functypestack))(
-This array corresponds element by element with tt(funcstack).
-Each element contains `tt(source)' for a sourced file, `tt(function)'
-for a function and `tt(eval)' for an tt(eval)'d expression.  At the top
-level of execution of a series of commands, tt($functypestack[1]) is
-empty if the commands are being executed as a script, or one of the
-previous strings if the commands are being executed as that type.
-)
 enditem()
diff --git a/Src/Modules/parameter.c b/Src/Modules/parameter.c
index 02a642b..0385a70 100644
--- a/Src/Modules/parameter.c
+++ b/Src/Modules/parameter.c
@@ -640,41 +640,6 @@ funcfiletracegetfn(UNUSED(Param pm))
     return ret;
 }
 
-/* Functions for the functypestack special parameter. */
-
-static char **
-functypestackgetfn(UNUSED(Param pm))
-{
-    Funcstack f;
-    int num;
-    char **ret, **p;
-
-    for (f = funcstack, num = 0; f; f = f->prev, num++);
-
-    ret = (char **) zhalloc((num + 1) * sizeof(char *));
-
-    for (f = funcstack, p = ret; f; f = f->prev, p++)
-    {
-	switch (f->tp)
-	{
-	case FS_SOURCE:
-	    *p = "source";
-	    break;
-
-	case FS_FUNC:
-	    *p = "function";
-	    break;
-
-	case FS_EVAL:
-	    *p = "eval";
-	    break;
-	}
-    }
-    *p = NULL;
-
-    return ret;
-}
-
 /* Functions for the builtins special parameter. */
 
 /**/
@@ -2081,8 +2046,6 @@ static const struct gsu_array funcsourcetrace_gsu =
 { funcsourcetracegetfn, arrsetfn, stdunsetfn };
 static const struct gsu_array funcfiletrace_gsu =
 { funcfiletracegetfn, arrsetfn, stdunsetfn };
-static const struct gsu_array functypestack_gsu =
-{ functypestackgetfn, arrsetfn, stdunsetfn };
 static const struct gsu_array reswords_gsu =
 { reswordsgetfn, arrsetfn, stdunsetfn };
 static const struct gsu_array disreswords_gsu =
@@ -2127,8 +2090,6 @@ static struct paramdef partab[] = {
 		 scanpmfunctions),
     SPECIALPMDEF("functrace", PM_ARRAY|PM_READONLY,
 	    &functrace_gsu, NULL, NULL),
-    SPECIALPMDEF("functypestack", PM_ARRAY|PM_READONLY,
-		 &functypestack_gsu, NULL, NULL),
     SPECIALPMDEF("galiases", 0,
 	    &pmgaliases_gsu, getpmgalias, scanpmgaliases),
     SPECIALPMDEF("history", PM_READONLY,

-- 
Peter Stephenson <p.w.stephenson@xxxxxxxxxxxx>
Web page now at http://homepage.ntlworld.com/p.w.stephenson/