From c1111e944784f68593964e528a9bd0dd6a6314fb Mon Sep 17 00:00:00 2001
From: =?utf8?q?Mattias=20Engdeg=C3=A5rd?= <mattiase@acm.org>
Date: Thu, 17 Feb 2022 14:39:42 +0100
Subject: [PATCH] Fix or remove outdated comments

* src/eval.c (funcall_lambda): Rewrite obsolete comment.
* src/bytecode.c (exec_byte_code): Remove lying comment and
unneeded #define.
* lisp/emacs-lisp/byte-opt.el: Remove car.  Keep pig.
(byte-compile-log-lap-1): Remove obsolete and irrelevant comment.
---
 lisp/emacs-lisp/byte-opt.el |  9 ---------
 src/bytecode.c              |  6 +-----
 src/eval.c                  | 20 ++++++++------------
 3 files changed, 9 insertions(+), 26 deletions(-)

diff --git a/lisp/emacs-lisp/byte-opt.el b/lisp/emacs-lisp/byte-opt.el
index 25898285faa..3ca0472efba 100644
--- a/lisp/emacs-lisp/byte-opt.el
+++ b/lisp/emacs-lisp/byte-opt.el
@@ -29,11 +29,6 @@
 ;; "No matter how hard you try, you can't make a racehorse out of a pig.
 ;; You can, however, make a faster pig."
 ;;
-;; Or, to put it another way, the Emacs byte compiler is a VW Bug.  This code
-;; makes it be a VW Bug with fuel injection and a turbocharger...  You're
-;; still not going to make it go faster than 70 mph, but it might be easier
-;; to get it there.
-;;
 
 ;; TO DO:
 ;;
@@ -74,10 +69,6 @@
 (eval-when-compile (require 'subr-x))
 
 (defun byte-compile-log-lap-1 (format &rest args)
-  ;; Newer byte codes for stack-ref make the slot 0 non-nil again.
-  ;; But the "old disassembler" is *really* ancient by now.
-  ;; (if (aref byte-code-vector 0)
-  ;;     (error "The old version of the disassembler is loaded.  Reload new-bytecomp as well"))
   (byte-compile-log-1
    (apply #'format-message format
      (let (c a)
diff --git a/src/bytecode.c b/src/bytecode.c
index bda9a39b7f3..96f1f905812 100644
--- a/src/bytecode.c
+++ b/src/bytecode.c
@@ -458,17 +458,13 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
 
 #ifdef BYTE_CODE_THREADED
 
-      /* A convenience define that saves us a lot of typing and makes
-	 the table clearer.  */
-#define LABEL(OP) [OP] = &&insn_ ## OP
-
       /* This is the dispatch table for the threaded interpreter.  */
       static const void *const targets[256] =
 	{
 	  [0 ... (Bconstant - 1)] = &&insn_default,
 	  [Bconstant ... 255] = &&insn_Bconstant,
 
-#define DEFINE(name, value) LABEL (name) ,
+#define DEFINE(name, value) [name] = &&insn_ ## name,
 	  BYTE_CODES
 #undef DEFINE
 	};
diff --git a/src/eval.c b/src/eval.c
index 7472e649afe..d3342289fbb 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -3243,19 +3243,15 @@ funcall_lambda (Lisp_Object fun, ptrdiff_t nargs,
   else if (COMPILEDP (fun))
     {
       syms_left = AREF (fun, COMPILED_ARGLIST);
+      /* Bytecode objects using lexical binding have an integral
+	 ARGLIST slot value: pass the arguments to the byte-code
+	 engine directly.  */
       if (FIXNUMP (syms_left))
-	/* A byte-code object with an integer args template means we
-	   shouldn't bind any arguments, instead just call the byte-code
-	   interpreter directly; it will push arguments as necessary.
-
-	   Byte-code objects with a nil args template (the default)
-	   have dynamically-bound arguments, and use the
-	   argument-binding code below instead (as do all interpreted
-	   functions, even lexically bound ones).  */
-	{
-	  return fetch_and_exec_byte_code (fun, XFIXNUM (syms_left),
-					   nargs, arg_vector);
-	}
+	return fetch_and_exec_byte_code (fun, XFIXNUM (syms_left),
+					 nargs, arg_vector);
+      /* Otherwise the bytecode object uses dynamic binding and the
+	 ARGLIST slot contains a standard formal argument list whose
+	 variables are bound dynamically below.  */
       lexenv = Qnil;
     }
 #ifdef HAVE_MODULES
-- 
2.39.5