Start fixing indirect calls of builtins.

3 files changed, 23 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 6f89d610..be2116fa 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2022-02-04         Arnold D. Robbins     <arnold@skeeve.com>
+
+	Start fixing issues with indirect calls of builtins.
+	Thanks to Denis Shirokov <cosmogen@gmail.com> for the initial report.
+	Much more remains to be done.
+
+	* builtin.c (do_length): Check number of arguments, fatal if not one.
+	If passed Node_var_new, turn it into the null string.
+	* interpret.h (r_interpret): For Op_indirect_call, pop the function
+	name off the stack.
+
 2022-01-05         Arnold D. Robbins     <arnold@skeeve.com>
 
 	* awkgram.y (change_namespace): New function. Extracted from
diff --git a/builtin.c b/builtin.c
index 91cd142f..125468ba 100644
--- a/builtin.c
+++ b/builtin.c
@@ -538,6 +538,10 @@ do_length(int nargs)
 	NODE *tmp;
 	size_t len;
 
+	// indirect call can pass too many arguments
+	if (nargs != 1)
+		fatal(_("length: called with %d arguments"), nargs);
+
 	tmp = POP();
 	if (tmp->type == Node_var_array) {
 		static bool warned = false;
@@ -561,6 +565,10 @@ do_length(int nargs)
 
 		size = assoc_length(tmp);
 		return make_number(size);
+	} else if (tmp->type == Node_var_new) {
+		// this can happen from an indirect call
+		DEREF(tmp);
+		tmp = dupnode(Nnull_string);
 	}
 
 	assert(tmp->type == Node_val);
diff --git a/interpret.h b/interpret.h
index d52d537e..071d6497 100644
--- a/interpret.h
+++ b/interpret.h
@@ -1132,6 +1132,7 @@ match_re:
 			NODE *f = NULL;
 			int arg_count;
 			char save;
+			NODE *function_name;
 
 			arg_count = (pc + 1)->expr_count;
 			t1 = PEEK(arg_count);	/* indirect var */
@@ -1174,6 +1175,9 @@ match_re:
 					r = the_func(arg_count);
 				str_restore(t1, save);
 
+				function_name = POP();	// pop function name off stack
+				DEREF(function_name);
+
 				PUSH(r);
 				break;
 			} else if (f->type != Node_func) {