commit f1f60f859cdbb2638b3662ccf7b1d179865fe7dc
author Bram Moolenaar <Bram@vim.org> Sat Jan 16 15:40:53 2016 +0100
committer Bram Moolenaar <Bram@vim.org> Sat Jan 16 15:40:53 2016 +0100
tree 739551087fb1b9948568366dc5d6187861dbcaf5
parent e39b3d9fb4e4006684c33847d1ef6a0d742699dd

patch 7.4.1102
Problem:    Debugger has no stack backtrace support.
Solution:   Add "backtrace", "frame", "up" and "down" commands. (Alberto
            Fanjul, closes #433)

src/eval.c

diff --git a/src/eval.c b/src/eval.c
index e97ddc4..1e2a041 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -812,6 +812,7 @@
 static dictitem_T *find_var __ARGS((char_u *name, hashtab_T **htp, int no_autoload));
 static dictitem_T *find_var_in_ht __ARGS((hashtab_T *ht, int htname, char_u *varname, int no_autoload));
 static hashtab_T *find_var_ht __ARGS((char_u *name, char_u **varname));
+static funccall_T *get_funccal __ARGS((void));
 static void vars_clear_ext __ARGS((hashtab_T *ht, int free_val));
 static void delete_var __ARGS((hashtab_T *ht, hashitem_T *hi));
 static void list_one_var __ARGS((dictitem_T *v, char_u *prefix, int *first));
@@ -21735,7 +21736,7 @@
 
 	if (current_funccal == NULL)
 	    return &globvarht;			/* global variable */
-	return &current_funccal->l_vars.dv_hashtab; /* l: variable */
+	return &get_funccal()->l_vars.dv_hashtab; /* l: variable */
     }
     *varname = name + 2;
     if (*name == 'g')				/* global variable */
@@ -21756,9 +21757,9 @@
     if (*name == 'v')				/* v: variable */
 	return &vimvarht;
     if (*name == 'a' && current_funccal != NULL) /* function argument */
-	return &current_funccal->l_avars.dv_hashtab;
+	return &get_funccal()->l_avars.dv_hashtab;
     if (*name == 'l' && current_funccal != NULL) /* local function variable */
-	return &current_funccal->l_vars.dv_hashtab;
+	return &get_funccal()->l_vars.dv_hashtab;
     if (*name == 's'				/* script variable */
 	    && current_SID > 0 && current_SID <= ga_scripts.ga_len)
 	return &SCRIPT_VARS(current_SID);
@@ -21766,6 +21767,32 @@
 }
 
 /*
+ * Get function call environment based on bactrace debug level
+ */
+    static funccall_T *
+get_funccal()
+{
+    int		i;
+    funccall_T	*funccal;
+    funccall_T	*temp_funccal;
+
+    funccal = current_funccal;
+    if (debug_backtrace_level > 0)
+    {
+        for (i = 0; i < debug_backtrace_level; i++)
+        {
+            temp_funccal = funccal->caller;
+            if (temp_funccal)
+                funccal = temp_funccal;
+	    else
+                /* backtrace level overflow. reset to max */
+                debug_backtrace_level = i;
+        }
+    }
+    return funccal;
+}
+
+/*
  * Get the string value of a (global/local) variable.
  * Note: see get_tv_string() for how long the pointer remains valid.
  * Returns NULL when it doesn't exist.