From: Kevin Ryde <user42@zip.com.au>
Date: Tue, 4 Nov 2003 21:18:58 +0000 (+0000)
Subject: (Function Portability): Add notes on signal
X-Git-Tag: AUTOCONF-2.59~5
X-Git-Url: http://git.ipfire.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=fcf298e6c144f401d62aa1757da0c654bf87531d;p=thirdparty%2Fautoconf.git

(Function Portability): Add notes on signal
handler return type, as per AC_TYPE_SIGNAL.
---

diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index 0b997572..253a94b6 100644
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -3560,6 +3560,19 @@ case and instead @code{unsetenv} must be used.
 On MINGW, a call @code{putenv("FOO=")} removes @samp{FOO} from the
 environment, rather than inserting it with an empty value.
 
+@item @code{signal} handler
+@c @fuindex signal
+@prindex @code{signal}
+Normally @code{signal} takes a handler function with a return type of
+@code{void}, but some old systems required @code{int} instead.  Any
+actual @code{int} value returned is not used, this is only a
+difference in the function prototype demanded.
+
+All systems we know of in current use take @code{void}.  Presumably
+@code{int} was to support K&R C, where of course @code{void} is not
+available.  @code{AC_TYPE_SIGNAL} (@pxref{Particular Types}) can be
+used to establish the correct type in all cases.
+
 @item @code{snprintf}
 @c @fuindex snprintf
 @prindex @code{snprintf}