From bb8f2c32306445979be10a91bd4a3febf34c554e Mon Sep 17 00:00:00 2001 From: Martin Liska Date: Mon, 12 Apr 2021 13:42:33 +0200 Subject: [PATCH] docs: update symver attribute description gcc/ChangeLog: * doc/extend.texi: Be more precise in documentation of symver attribute. --- gcc/doc/extend.texi | 28 +++++++++++++++++++--------- 1 file changed, 19 insertions(+), 9 deletions(-) diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi index e28e18609906..6542ada6583c 100644 --- a/gcc/doc/extend.texi +++ b/gcc/doc/extend.texi @@ -3848,23 +3848,33 @@ foo_v1 (void) Will produce a @code{.symver foo_v1, foo@@VERS_1} directive in the assembler output. -One can also define multiple version for a given symbol. +One can also define multiple version for a given symbol +(starting from binutils 2.35). @smallexample __attribute__ ((__symver__ ("foo@@VERS_2"), __symver__ ("foo@@VERS_3"))) int symver_foo_v1 (void) @{ @} - -__attribute__ ((__symver__ ("bar@@VERS_2"))) -__attribute__ ((__symver__ ("bar@@VERS_3"))) -int symver_bar_v1 (void) -@{ -@} @end smallexample -This example creates an alias of @code{foo_v1} with symbol name -@code{symver_foo_v1} which will be version @code{VERS_2} of @code{foo}. +This example creates a symbol name @code{symver_foo_v1} +which will be version @code{VERS_2} and @code{VERS_3} of @code{foo}. + +If you have an older release of binutils, then symbol alias needs to +be used: + +@smallexample +__attribute__ ((__symver__ ("foo@@VERS_2"))) +int foo_v1 (void) +{ + return 0; +} + +__attribute__ ((__symver__ ("foo@VERS_3"))) +__attribute__ ((alias ("foo_v1"))) +int symver_foo_v1 (void); +@end smallexample Finally if the parameter is @code{"@var{name2}@@@@@var{nodename}"} then in addition to creating a symbol version (as if -- 2.47.2