[PATCH 1/2] IPA symver: allow multiple symvers for a definition

[Jan Hubicka]

> 
> gcc/ChangeLog:
> 
> 	* cgraphunit.c (process_symver_attribute): Allow multiple
> 	symver attributes for one symbol.
> 	* doc/extend.texi: Document the change.
> 
> gcc/testsuite/ChangeLog:
> 
> 	* lib/target-supports-dg.exp: Add dg-require-symver.
> 	* lib/target-supports.exp: Likewise.
> 	* gcc.dg/ipa/symver1.c: New test.
> ---
>  gcc/cgraphunit.c                         | 143 ++++++++++++-----------
>  gcc/doc/extend.texi                      |  10 +-
>  gcc/testsuite/gcc.dg/ipa/symver1.c       |  11 ++
>  gcc/testsuite/lib/target-supports-dg.exp |  10 ++
>  gcc/testsuite/lib/target-supports.exp    |  12 ++
>  5 files changed, 110 insertions(+), 76 deletions(-)
>  create mode 100644 gcc/testsuite/gcc.dg/ipa/symver1.c
> 

>  @smallexample
> -__attribute__ ((__symver__ ("foo@@VERS_2")))
> -__attribute__ ((alias ("foo_v1")))
> -int symver_foo_v1 (void);
> +__attribute__ ((__symver__ ("foo@@VERS_2"), ("foo@@VERS_3")))
> +int symver_foo_v1 (void)
So we can still write it as follows:
+__attribute__ ((__symver__ ("foo@@VERS_2"))))
+__attribute__ ((__symver__ ("foo@@VERS_3"))))
+int symver_foo_v1 (void)

I think we should support this syntax so the versions can be added
separately by macros mixed with other attributs....

Honza
> +@{
> +@}
>  @end smallexample
>  
>  This example creates an alias of @code{foo_v1} with symbol name
> diff --git a/gcc/testsuite/gcc.dg/ipa/symver1.c b/gcc/testsuite/gcc.dg/ipa/symver1.c
> new file mode 100644
> index 00000000000..645de7ea259
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/ipa/symver1.c
> @@ -0,0 +1,11 @@
> +/* { dg-do compile } */
> +
> +__attribute__ ((__symver__ ("foo@VER_2")))
> +__attribute__ ((__symver__ ("foo@VER_3")))
> +int foo()
> +{
> +  return 2;
> +}
> +
> +/* { dg-final { scan-assembler ".symver.*foo, foo@VER_2" } } */
> +/* { dg-final { scan-assembler ".symver.*foo, foo@VER_3" } } */
> diff --git a/gcc/testsuite/lib/target-supports-dg.exp b/gcc/testsuite/lib/target-supports-dg.exp
> index 5bb99f4e8f9..4a03eaae9ce 100644
> --- a/gcc/testsuite/lib/target-supports-dg.exp
> +++ b/gcc/testsuite/lib/target-supports-dg.exp
> @@ -665,3 +665,13 @@ if { [info procs saved-dg-process-target] == [list] } {
>  	return [dg-process-target-1 $selector]
>      }
>  }
> +
> +# If this target does not support the "symver" attribute, skip this
> +# test.
> +
> +proc dg-require-symver { args } {
> +    if { ![ check_symver_available ] } {
> +	upvar dg-do-what dg-do-what
> +	set dg-do-what [list [lindex ${dg-do-what} 0] "N" "P"]
> +    }
> +}
> diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
> index c24330a27ab..f3fc5b80aea 100644
> --- a/gcc/testsuite/lib/target-supports.exp
> +++ b/gcc/testsuite/lib/target-supports.exp
> @@ -10445,3 +10445,15 @@ proc check_effective_target_large_initializer { } {
>  
>      return 1
>  }
> +# Returns 1 if the target toolchain supports extended
> +# syntax of .symver directive, 0 otherwise.
> +
> +proc check_symver_available { } {
> +    return [check_no_compiler_messages symver_available object {
> +	    int foo(void) { return 0; }
> +	    int main (void) {
> +		asm volatile (".symver foo,foo@VER_1, local");
> +		return 0;
> +	    }
> +	}]
> +}