From 968dc26df61f4577c6a1df5734de21c1504d2c79 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Tue, 2 Aug 2016 17:18:08 +0200 Subject: [PATCH] Add support for referencing specific symbol versions This is needed for writing tests of compat symbols. --- ChangeLog | 12 ++++++++++++ include/libc-symbols.h | 19 ++++++++++++++----- include/shlib-compat.h | 18 +++++++++++------- 3 files changed, 37 insertions(+), 12 deletions(-) diff --git a/ChangeLog b/ChangeLog index 3edcce4d9d..8c2eb8e48f 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,15 @@ +2016-08-02 Florian Weimer + + Support linking against compatibility symbols, for use in tests. + * include/libc-symbols.h (symbol_version_reference): New macro. + (symbol_version): Use it. + * include/shlib-compat.h: Unconditionally include . + (compat_symbol): Use compat_symbol_reference. + (compat_symbol_1, compat_symbol_2): Remove. + (compat_symbol_reference, compat_symbol_reference_1) + (compat_symbol_reference_2): New macro. Use + symbol_version_reference. + 2016-08-02 Florian Weimer [BZ #19469] diff --git a/include/libc-symbols.h b/include/libc-symbols.h index 4548e097dc..c2b499ae36 100644 --- a/include/libc-symbols.h +++ b/include/libc-symbols.h @@ -282,19 +282,28 @@ for linking") past the last element in SET. */ #define symbol_set_end_p(set, ptr) ((ptr) >= (void *const *) &__stop_##set) +/* Use symbol_version_reference to specify the version a symbol + reference should link to. Use symbol_version or + default_symbol_version for the definition of a versioned symbol. + The difference is that the latter is a no-op in non-shared + builds. */ +#ifdef __ASSEMBLER__ +# define symbol_version_reference(real, name, version) \ + .symver real, name##@##version +#else /* !__ASSEMBLER__ */ +# define symbol_version_reference(real, name, version) \ + __asm__ (".symver " #real "," #name "@" #version) +#endif + #ifdef SHARED # define symbol_version(real, name, version) \ - _symbol_version(real, name, version) + symbol_version_reference(real, name, version) # define default_symbol_version(real, name, version) \ _default_symbol_version(real, name, version) # ifdef __ASSEMBLER__ -# define _symbol_version(real, name, version) \ - .symver real, name##@##version # define _default_symbol_version(real, name, version) \ .symver real, name##@##@##version # else -# define _symbol_version(real, name, version) \ - __asm__ (".symver " #real "," #name "@" #version) # define _default_symbol_version(real, name, version) \ __asm__ (".symver " #real "," #name "@@" #version) # endif diff --git a/include/shlib-compat.h b/include/shlib-compat.h index c1c5e2c3b1..025c7316dd 100644 --- a/include/shlib-compat.h +++ b/include/shlib-compat.h @@ -19,10 +19,10 @@ #ifndef _SHLIB_COMPAT_H #define _SHLIB_COMPAT_H 1 -#ifdef SHARED - # include +#ifdef SHARED + /* The file abi-versions.h (generated by scripts/abi-versions.awk) defines symbols like `ABI_libm_GLIBC_2_0' for each version set in the source code for each library. For a version set that is subsumed by a later @@ -62,11 +62,7 @@ default_symbol_version (local, symbol, name) # define compat_symbol(lib, local, symbol, version) \ - compat_symbol_1 (lib, local, symbol, version) -# define compat_symbol_1(lib, local, symbol, version) \ - compat_symbol_2 (local, symbol, VERSION_##lib##_##version) -# define compat_symbol_2(local, symbol, name) \ - symbol_version (local, symbol, name) + compat_symbol_reference (lib, local, symbol, version) #else @@ -82,6 +78,14 @@ #endif +/* Use compat_symbol_reference for a reference to a specific version + of a symbol. Use compat_symbol to define such a symbol. */ +#define compat_symbol_reference(lib, local, symbol, version) \ + compat_symbol_reference_1 (lib, local, symbol, version) +#define compat_symbol_reference_1(lib, local, symbol, version) \ + compat_symbol_reference_2 (local, symbol, VERSION_##lib##_##version) +#define compat_symbol_reference_2(local, symbol, name) \ + symbol_version_reference (local, symbol, name) # ifdef LINK_OBSOLETE_RPC /* Export the symbol for both static and dynamic linking. */