Add the new macro with-suppressed-warnings

* lisp/emacs-lisp/byte-run.el (with-suppressed-warnings): New macro.

* doc/lispref/compile.texi (Compiler Errors): Document
with-suppressed-warnings and deemphasise with-no-warnings
slightly.

* lisp/emacs-lisp/bytecomp.el (byte-compile--suppressed-warnings):
New internal variable.
(byte-compile-warning-enabled-p): Heed
byte-compile--suppressed-warnings, bound via with-suppressed-warnings.
(byte-compile-initial-macro-environment): Provide a macro
expansion of with-suppressed-warnings.
(byte-compile-file-form-with-suppressed-warnings): New byte hunk
handler for the suppressed symbol machinery.
(byte-compile-suppressed-warnings): Ditto for the byteop.
(byte-compile-file-form-defmumble): Ditto.
(byte-compile-form, byte-compile-normal-call)
(byte-compile-normal-call, byte-compile-variable-ref)
(byte-compile-set-default, byte-compile-variable-set)
(byte-compile-function-form, byte-compile-set-default)
(byte-compile-warn-obsolete, byte-compile--declare-var): Pass the
symbol being warned in to byte-compile-warning-enabled-p.

* test/lisp/emacs-lisp/bytecomp-tests.el (test-suppression): New
function.
(bytecomp-test--with-suppressed-warnings): Tests.

1 files changed, 28 insertions, 0 deletions

diff --git a/lisp/emacs-lisp/byte-run.el b/lisp/emacs-lisp/byte-run.el
index 842d1d48b45..6a21a0c909d 100644
--- a/lisp/emacs-lisp/byte-run.el
+++ b/lisp/emacs-lisp/byte-run.el
@@ -494,6 +494,34 @@ is enabled."
   ;; The implementation for the interpreter is basically trivial.
   (car (last body)))
 
+(defmacro with-suppressed-warnings (_warnings &rest body)
+  "Like `progn', but prevents compiler WARNINGS in BODY.
+
+WARNINGS is an associative list where the first element of each
+item is a warning type, and the rest of the elements in each item
+are symbols they apply to.  For instance, if you want to suppress
+byte compilation warnings about the two obsolete functions `foo'
+and `bar', as well as the function `zot' being called with the
+wrong number of parameters, say
+
+\(with-suppressed-warnings ((obsolete foo bar)
+                           (callargs zot))
+  (foo (bar))
+  (zot 1 2))
+
+The warnings that can be suppressed are a subset of the warnings
+in `byte-compile-warning-types'; see this variable for a fuller
+explanation of the warning types.  The types that can be
+suppressed with this macro are `free-vars', `callargs',
+`redefine', `obsolete', `interactive-only', `lexical', `mapcar',
+`constants' and `suspicious'.
+
+For the `mapcar' case, only the `mapcar' function can be used in
+the symbol list.  For `suspicious', only `set-buffer' can be used."
+  (declare (debug (sexp &optional body)) (indent 1))
+  ;; The implementation for the interpreter is basically trivial.
+  `(progn ,@body))
+
 
 (defun byte-run--unescaped-character-literals-warning ()
   "Return a warning about unescaped character literals.