Re: Emacs 23.1.96 (git HEAD) crashing at startup.

[Chong Yidong]

Eli Zaretskii <address@hidden> writes:

> Yes, he is:
>
> So I think this is a known issue with GCC 4.5 produced optimized code.

Since this bug is coming up with some regularity, how bout the following
configure check?  It signals an error if gcc-4.5 is used with O2 in
CFLAGS.

Could someone with GCC 4.5 test it?

*** configure   2010-04-20 01:29:37 +0000
--- configure   2010-05-02 18:44:10 +0000
***************
*** 25559,25564 ****
--- 25559,25573 ----
  CFLAGS="$REAL_CFLAGS"
  CPPFLAGS="$REAL_CPPFLAGS"
  
+ ## GCC 4.5 has a bug that makes Emacs crash.  See etc/PROBLEMS.
+ if test x"`gcc --version 2> /dev/null | grep ' 4.5.0'`" != x; then
+     if test x"`echo $CFLAGS | grep O2`" != x; then
+        { { $as_echo "$as_me:$LINENO: error: GCC 4.5.0 is buggy; can't compile 
Emacs with -O2'." >&5
+ $as_echo "$as_me: error: GCC 4.5.0 is buggy; can't compile Emacs with -O2'." 
>&2;}
+    { (exit 1); exit 1; }; }
+     fi
+ fi
+ 
  #### Find out which version of Emacs this is.
  version=`grep 'defconst[       ]*emacs-version' ${srcdir}/lisp/version.el \
         | sed -e 's/^[^"]*"\([^"]*\)".*$/\1/'`

*** configure.in        2010-04-20 01:29:37 +0000
--- configure.in        2010-05-02 18:27:15 +0000
***************
*** 2600,2605 ****
--- 2600,2612 ----
  CFLAGS="$REAL_CFLAGS"
  CPPFLAGS="$REAL_CPPFLAGS"
  
+ ## GCC 4.5 has a bug that makes Emacs crash.  See etc/PROBLEMS.
+ if test x"`gcc --version 2> /dev/null | grep ' 4.5.0'`" != x; then
+     if test x"`echo $CFLAGS | grep O2`" != x; then
+        AC_MSG_ERROR([GCC 4.5.0 is buggy; can't compile Emacs with -O2'.])
+     fi
+ fi
+ 
  #### Find out which version of Emacs this is.
  [version=`grep 'defconst[      ]*emacs-version' ${srcdir}/lisp/version.el \
         | sed -e 's/^[^"]*"\([^"]*\)".*$/\1/'`]