------- Comment #1 from mschulze at ivs dot cs dot ovgu dot de 2010-06-18
10:11 -------
(In reply to comment #0)
> IMO, in the following test program the variable s within the class template
> may
> be optimized-away in every case. Although, the variable is used as an argument
> for a function call, it is omit-able due to the definition of function t1 as
> "static inline" with its empty body. If I use instead of a class template a
> function template, this contained static local variable will be
> optimized-away,
> as expected.
>
> [mschu...@teeth tst]$ cat test.cc
> static inline void t1(const char* s) {}
>
> template <typename T>
> struct class_template {
> class_template() {
> static const char s[]="class_template";
> t1(s);
> }
> };
>
> template <typename T>
> static inline void function_template() {
> static const char s[]="function_template";
> t1(s);
> }
>
> int main(int, char**) {
> class_template<int> t;
> function_template<int>();
> return 0;
> }
>
> I compiled the program with
[mschu...@teeth tst]$ g++ -Wall -Os test.cc -o t
> [mschu...@teeth tst]$ g++ -v
> Using built-in specs.
> Target: i586-redhat-linux
> Configured with: ../configure --prefix=/usr --mandir=/usr/share/man
> --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla
> --enable-bootstrap --enable-shared --enable-threads=posix
> --enable-checking=release --with-system-zlib --enable-__cxa_atexit
> --disable-libunwind-exceptions
> --enable-languages=c,c++,objc,obj-c++,java,fortran,ada --enable-java-awt=gtk
> --disable-dssi --enable-plugin
> --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-1.5.0.0/jre
> --enable-libgcj-multifile --enable-java-maintainer-mode
> --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --disable-libjava-multilib
> --with-ppl --with-cloog --with-tune=generic --with-arch=i586
> --build=i586-redhat-linux
> Thread model: posix
> gcc version 4.4.1 20090725 (Red Hat 4.4.1-2) (GCC)
>
> and then I used the string program to list the contained strings.
>
> [mschu...@teeth tst]$ strings t
> /lib/ld-linux.so.2
> libstdc++.so.6
> __gmon_start__
> _Jv_RegisterClasses
> __gxx_personality_v0
> libm.so.6
> libgcc_s.so.1
> libc.so.6
> _IO_stdin_used
> __libc_start_main
> CXXABI_1.3
> GLIBC_2.0
> PTRhP
> QVhD
> [^_]
> class_template
> [mschu...@teeth tst]$
>
> The class_template string is present, but the function_template string not. If
> I omit the static keyword, it will disappear, too.
>
>
>
> Thanks in advance,
> Michael
>
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44577
