Merge from origin/emacs-26

8ac621b (origin/emacs-26) Document DEFUN attributes
16d0cc7 * etc/NEWS: Add an entry for auth-source-pass.
cc1702f Fix the MSDOS build
daa9e85 Improve warning and error messages
7612dd1 Adjust eieio persistence tests for expected failure
f0cf4dc Let eieio-persistent-read read what object-write has written
40ad1ff Handle possible classtype values in eieio-persistent-read
4ec935d Add new tests for eieio persistence
47917d8 * lisp/gnus/gnus-cloud.el (gnus-cloud-synced-files): Fix doc ...
e32f352 * lisp/ibuf-ext.el (ibuffer-never-search-content-mode): Fix t...
5268f30 * doc/lispref/windows.texi (Selecting Windows): Fix a typo.
143b485 * doc/lispref/internals.texi (Writing Emacs Primitives): Fix ...
4ab4551 Firm up documentation of generalized variables
a5bf099 Improve documentation of Auto-Revert mode
ed05eaa Improvements in dired.texi

Conflicts:
	etc/NEWS

1 files changed, 39 insertions, 2 deletions

diff --git a/doc/lispref/internals.texi b/doc/lispref/internals.texi
index 76be7bf0ac6..7ae5b5c693d 100644
--- a/doc/lispref/internals.texi
+++ b/doc/lispref/internals.texi
@@ -735,7 +735,7 @@ Lisp form.  For example:
 
 @example
 @group
-DEFUN ("foo", Ffoo, Sfoo, 0, UNEVALLED,
+DEFUN ("foo", Ffoo, Sfoo, 0, UNEVALLED, 0
        "(list (read-char-by-name \"Insert character: \")\
               (prefix-numeric-value current-prefix-arg)\
               t))",
@@ -768,6 +768,43 @@ the actual documentation.  The others have placeholders beginning with
 All the usual rules for documentation strings in Lisp code
 (@pxref{Documentation Tips}) apply to C code documentation strings
 too.
+
+The documentation string can be followed by a list of C function
+attributes for the C function that implements the primitive, like
+this:
+
+@example
+@group
+DEFUN ("bar", Fbar, Sbar, 0, UNEVALLED, 0
+  doc: /* @dots{} /*
+  attributes: @var{attr1} @var{attr2} @dots{})
+@end group
+@end example
+
+@noindent
+You can specify more than a single attribute, one after the other.
+Currently, only the following attributes are recognized:
+
+@table @code
+@item noreturn
+Declares the C function as one that never returns.  This corresponds
+to the C11 keyword @code{_Noreturn} and to @w{@code{__attribute__
+((__noreturn__))}} attribute of GCC (@pxref{Function Attributes,,,
+gcc, Using the GNU Compiler Collection}).
+
+@item const
+Declares that the function does not examine any values except its
+arguments, and has no effects except the return value.  This
+corresponds to @w{@code{__attribute__ ((__const__))}} attribute of
+GCC.
+
+@item noinline
+This corresponds to @w{@code{__attribute__ ((__noinline__))}}
+attribute of GCC, which prevents the function from being considered
+for inlining.  This might be needed, e.g., to countermand effects of
+link-time optimizations on stack-based variables.
+@end table
+
 @end table
 
   After the call to the @code{DEFUN} macro, you must write the
@@ -850,7 +887,7 @@ defined with @code{DEFVAR_BOOL} are automatically added to the list
 @code{byte-boolean-vars} used by the byte compiler.
 
 @cindex defining customization variables in C
-  If you want to make a Lisp variables that is defined in C behave
+  If you want to make a Lisp variable that is defined in C behave
 like one declared with @code{defcustom}, add an appropriate entry to
 @file{cus-start.el}.