From 9ef3f8e82036a28c4f0375ec65eb25864a5240ca Mon Sep 17 00:00:00 2001 From: Brad King Date: Wed, 13 Jan 2010 08:13:46 -0500 Subject: Restore -rdynamic in Linux build rules The commit "Drop -rdynamic from Linux build rules" removed default use of the flag on Linux. It was expected to be compatible because any project using plugins should set ENABLE_EXPORTS on its executables to export their symbols for use by the plugins in a cross-platform way. However, it is possible to build without ENABLE_EXPORTS and load plugins that do not link to any symbols from the executable explicitly. These plugins may need to see RTTI and other executable symbols needed by the language implementation. Executables using such plugins were broken by the change. If we want to remove the -rdynamic flag in the future we should do so in a compatible way. At that time we should also remove equivalent flags on other platforms (like -bexpall on AIX). We will either need a policy or an explicit API to disable symbol exports on executables. The primary purpose of the above-mentioned commit was to avoid passing the -rdynamic flag to compilers on Linux that do not support it. In this commit we restore the flag but only on GNU and Intel compilers which are known to support it. See issue #9985. --- Modules/Platform/Linux-GNU.cmake | 3 +++ Modules/Platform/Linux-Intel.cmake | 4 ++++ 2 files changed, 7 insertions(+) diff --git a/Modules/Platform/Linux-GNU.cmake b/Modules/Platform/Linux-GNU.cmake index df6295b..d257f34 100644 --- a/Modules/Platform/Linux-GNU.cmake +++ b/Modules/Platform/Linux-GNU.cmake @@ -19,4 +19,7 @@ endif() set(__LINUX_COMPILER_GNU 1) macro(__linux_compiler_gnu lang) + # We pass this for historical reasons. Projects may have + # executables that use dlopen but do not set ENABLE_EXPORTS. + set(CMAKE_SHARED_LIBRARY_LINK_${lang}_FLAGS "-rdynamic") endmacro() diff --git a/Modules/Platform/Linux-Intel.cmake b/Modules/Platform/Linux-Intel.cmake index 1474051..dff90e9 100644 --- a/Modules/Platform/Linux-Intel.cmake +++ b/Modules/Platform/Linux-Intel.cmake @@ -34,6 +34,10 @@ macro(__linux_compiler_intel lang) set(CMAKE_SHARED_LIBRARY_${lang}_FLAGS "-fPIC") set(CMAKE_SHARED_LIBRARY_CREATE_${lang}_FLAGS "-shared") + # We pass this for historical reasons. Projects may have + # executables that use dlopen but do not set ENABLE_EXPORTS. + set(CMAKE_SHARED_LIBRARY_LINK_${lang}_FLAGS "-rdynamic") + if(XIAR) # INTERPROCEDURAL_OPTIMIZATION set(CMAKE_${lang}_COMPILE_OPTIONS_IPO -ipo) -- cgit v0.12