From 5d9934312d0b553eafb7c690487215cff7ddedb3 Mon Sep 17 00:00:00 2001 From: Brad King Date: Wed, 14 Dec 2011 13:59:39 -0500 Subject: Do not link private dependent shared libraries on OS X > 10.4 The default OS X 10.4 linker incorrectly searches for dependencies of linked shared libraries only under the -isysroot location. It fails to find dependencies of linked shared libraries in cases such as the ExportImport test. It produces errors like: /usr/libexec/gcc/i686-apple-darwin8/4.0.1/ld: warning can't open dynamic library: libtestLib3Imp.dylib referenced from: /.../ExportImport/Root/lib/libtestLib3lib.1.2.dylib (checking for undefined symbols may be affected) (No such file or directory, errno = 2) /usr/libexec/gcc/i686-apple-darwin8/4.0.1/ld: Undefined symbols: _testLib3Imp referenced from libtestLib3lib expected to be defined in libtestLib3Imp.dylib or with CMAKE_SKIP_RPATH off to enable install_name in the Export side: /usr/libexec/gcc/i686-apple-darwin8/4.0.1/ld: warning can't open dynamic library: /Developer/SDKs/MacOSX10.4u.sdk/.../ExportImport/Export/impl/libtestLib3Imp.dylib referenced from: /.../ExportImport/Export/libtestLib3lib.1.2.dylib (checking for undefined symbols may be affected) (No such file or directory, errno = 2) /usr/libexec/gcc/i686-apple-darwin8/4.0.1/ld: Undefined symbols:_testLib3Imp referenced from libtestLib3lib expected to be defined in /.../ExportImport/Export/impl/libtestLib3Imp.dylib Note how "/Developer/SDKs/MacOSX10.4u.sdk" is prepended to the dependent library path. Commit 2cff26fa (Support linking to shared libs with dependent libs, 2008-01-31) and commit 82fcaebe (Pass dependent library search path to linker on some platforms, 2008-02-01) worked around the problem by defining platform variable CMAKE_LINK_DEPENDENT_LIBRARY_FILES. It tells CMake to link to dependent libraries explicitly by their path thus telling the linker where to find them. Unfortunately the workaround had the side effect of linking dependent libraries and defeats most benefits of LINK_INTERFACE_LIBRARIES. Fortunately OS X 10.5 and above do not need to find transitive dependencies at all so we can avoid the workaround on Modern OS X. --- Modules/Platform/Darwin.cmake | 12 +++++++----- Source/cmComputeLinkInformation.cxx | 4 +++- 2 files changed, 10 insertions(+), 6 deletions(-) diff --git a/Modules/Platform/Darwin.cmake b/Modules/Platform/Darwin.cmake index c11c8fb..867c788 100644 --- a/Modules/Platform/Darwin.cmake +++ b/Modules/Platform/Darwin.cmake @@ -187,11 +187,13 @@ IF(XCODE) SET(CMAKE_INCLUDE_SYSTEM_FLAG_CXX) ENDIF(XCODE) -# Need to list dependent shared libraries on link line. When building -# with -isysroot (for universal binaries), the linker always looks for -# dependent libraries under the sysroot. Listing them on the link -# line works around the problem. -SET(CMAKE_LINK_DEPENDENT_LIBRARY_FILES 1) +IF("${_CURRENT_OSX_VERSION}" VERSION_LESS "10.5") + # Need to list dependent shared libraries on link line. When building + # with -isysroot (for universal binaries), the linker always looks for + # dependent libraries under the sysroot. Listing them on the link + # line works around the problem. + SET(CMAKE_LINK_DEPENDENT_LIBRARY_FILES 1) +ENDIF() SET(CMAKE_C_CREATE_SHARED_LIBRARY_FORBIDDEN_FLAGS -w) SET(CMAKE_CXX_CREATE_SHARED_LIBRARY_FORBIDDEN_FLAGS -w) diff --git a/Source/cmComputeLinkInformation.cxx b/Source/cmComputeLinkInformation.cxx index f8ab686..edf6c35 100644 --- a/Source/cmComputeLinkInformation.cxx +++ b/Source/cmComputeLinkInformation.cxx @@ -161,7 +161,9 @@ listed on the command line. - On Windows, DLLs are not directly linked, and the import libraries have no transitive dependencies. - - On Mac, we need to actually list the transitive dependencies. + - On Mac OS X 10.5 and above transitive dependencies are not needed. + + - On Mac OS X 10.4 and below we need to actually list the dependencies. Otherwise when using -isysroot for universal binaries it cannot find the dependent libraries. Listing them on the command line tells the linker where to find them, but unfortunately also links -- cgit v0.12