diff options
Diffstat (limited to 'include/shlib-compat.h')
| -rw-r--r-- | include/shlib-compat.h | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/include/shlib-compat.h b/include/shlib-compat.h index f1c2fd8ed9..fafb5268a6 100644 --- a/include/shlib-compat.h +++ b/include/shlib-compat.h @@ -64,6 +64,41 @@ # define compat_symbol(lib, local, symbol, version) \ compat_symbol_reference (lib, local, symbol, version) +/* This is similar to compat_symbol, but allows versioning the same symbol + to multiple version without having multiple symbol definitions. For + instance: + + #if (SHLIB_COMPAT (libpthread, GLIBC_2_1_2, GLIBC_2_2)) + compat_symbol_unique (libc, old_foo, GLIBC_2_1_2) + #endif + + #if (SHLIB_COMPAT (libpthread, GLIBC_2_2_6, GLIBC_2_3)) + compat_symbol_unique (libc, old_foo, GLIBC_2_2_6) + #endif + + Internally it creates a unique strong alias to the input symbol and + creates one compat_symbol on the alias. Using the above example, + it is similar to: + + #if (SHLIB_COMPAT (libpthread, GLIBC_2_1_2, GLIBC_2_2)) + strong_alias (old_foo, old_foo__COUNTER__) + compat_symbol (libc, old_foo__COUNTER__, foo, GLIBC_2_2) + #endif. + + With __COUNTER__ being a monotonic number generated by the compiler. */ + +# define __compat_symbol_unique_concat(x, y) x ## y +# define _compat_symbol_unique_concat(x, y) \ + __compat_symbol_unique_concat (x, y) +# define _compat_symbol_unique_alias(name) \ + _compat_symbol_unique_concat (name, __COUNTER__) +# define _compat_symbol_unique(lib, orig_name, name, version) \ + strong_alias (orig_name, name) \ + compat_symbol (lib, name, orig_name, version) +# define compat_symbol_unique(lib, name, version) \ + _compat_symbol_unique (lib, name, _compat_symbol_unique_alias (name), \ + version) + #else /* Not compiling ELF shared libraries at all, so never any old versions. */ @@ -75,6 +110,7 @@ /* This should not appear outside `#if SHLIB_COMPAT (...)'. */ # define compat_symbol(lib, local, symbol, version) ... +# define compat_symbol_unique(lib, name, version) ... #endif |