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

Martin Liška mliska@suse.cz
Wed Aug 26 07:59:34 GMT 2020


On 8/25/20 8:48 PM, Jan Hubicka wrote:
>>
>> 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....

Yes, the syntax is supported as well and I'm adding that to documentation.

I'm going to push this commit.

Thanks for review,
Martin

> 
> 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;
>> +	    }
>> +	}]
>> +}
> 



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