[cmake] Make dependencies of lldb libraries private, take 2

[labath]

Summary

The dependencies of our libraries (only liblldb, really) we marked as public, which caused all
their dependencies to be repeated when linking any executables to them. This is a problem because
then all the .a files could end up being linked twice, once to liblldb and once
again to to the executable linking against liblldb (lldb, lldb-mi). As it turns out,
our build actually depends on this behavior:

• on windows, lldb does not have getopt, so it pulls it from inside liblldb, even though getopt is not a part of the exported interface of liblldb (maybe some of the bsd variants have this problem as well)
• lldb-mi uses llvm, which again is not exported by liblldb

This change does not actually fix these problems (that is going to be a hard
one), but it does make them explicit by moving this magic from add_lldb_library
to the places the executable targets are defined. That way, I can link the
additional .a files only on targets that really need it, and the other targets
can build cleanly and make sure we don't regress further. It also fixes the
LLVM_LINK_LLVM_DYLIB build on linux.

[beanz]

LGTM!

[labath]

@sylvestre.ledru : I believe this will fix the LINK_LLVM_DYLIB issue you were encountering. Let me know if you're still having problems after this.
@emaste @krytarowski : This has potential to break linking on *BSD. I'll keep an eye on the bots and respond accordingly.

[krytarowski]

Looks fine, thanks.

cmake/modules/AddLLDB.cmake

 function(lldb_link_common_libs name targetkind)
   if (NOT LLDB_USED_LIBS)
     return()
   endif()
 
   if(${targetkind} MATCHES "SHARED")
-    set(LINK_KEYWORD PUBLIC)
+    set(LINK_KEYWORD PRIVATE)
   endif()
 
   if(${targetkind} MATCHES "SHARED" OR ${targetkind} MATCHES "EXE")
     if (LLDB_LINKER_SUPPORTS_GROUPS)
       target_link_libraries(${name} ${LINK_KEYWORD}
                             -Wl,--start-group ${LLDB_USED_LIBS} -Wl,--end-group)
     else()
       target_link_libraries(${name} ${LINK_KEYWORD} ${LLDB_USED_LIBS})
macro(add_lldb_library name)
   #PIC not needed on Win
   if (NOT MSVC)
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fPIC")
   endif()
 
   if (PARAM_OBJECT)
     add_library(${name} ${libkind} ${srcs})
   else()
-    llvm_add_library(${name} ${libkind} DISABLE_LLVM_LINK_LLVM_DYLIB ${srcs})
-
-    lldb_link_common_libs(${name} "${libkind}")
-
     if (PARAM_SHARED)
       if (LLDB_LINKER_SUPPORTS_GROUPS)
-        target_link_libraries(${name} PUBLIC
-                    -Wl,--start-group ${CLANG_USED_LIBS} -Wl,--end-group)
+        llvm_add_library(${name} ${libkind} ${srcs} LINK_LIBS
+                                -Wl,--start-group ${LLDB_USED_LIBS} -Wl,--end-group
+                                -Wl,--start-group ${CLANG_USED_LIBS} -Wl,--end-group
+          )
       else()
-        target_link_libraries(${name} PUBLIC ${CLANG_USED_LIBS})
+        llvm_add_library(${name} ${libkind} ${srcs} LINK_LIBS
+                                ${LLDB_USED_LIBS} ${CLANG_USED_LIBS}
+          )
       endif()
+    else()
+      llvm_add_library(${name} ${libking} ${srcs})
     endif()
-    llvm_config(${name} ${LLVM_LINK_COMPONENTS} ${LLVM_PRIVATE_LINK_COMPONENTS})
 
     if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY OR ${name} STREQUAL "liblldb")
       if (PARAM_SHARED)
         set(out_dir lib${LLVM_LIBDIR_SUFFIX})
         if(${name} STREQUAL "liblldb" AND LLDB_BUILD_FRAMEWORK)
           set(out_dir ${LLDB_FRAMEWORK_INSTALL_DIR})
         endif()
         install(TARGETS ${name}
if(CLANG_TABLEGEN_TARGETS)
     add_dependencies(${name} ${CLANG_TABLEGEN_TARGETS})
   endif()
 
   set_target_properties(${name} PROPERTIES FOLDER "lldb libraries")
 endmacro(add_lldb_library)
 
 macro(add_lldb_executable name)
   cmake_parse_arguments(ARG "INCLUDE_IN_FRAMEWORK" "" "" ${ARGN})
-  add_llvm_executable(${name} DISABLE_LLVM_LINK_LLVM_DYLIB ${ARG_UNPARSED_ARGUMENTS})
+  add_llvm_executable(${name} ${ARG_UNPARSED_ARGUMENTS})
   set_target_properties(${name} PROPERTIES
     FOLDER "lldb executables")
 
   if(LLDB_BUILD_FRAMEWORK)
     if(ARG_INCLUDE_IN_FRAMEWORK)
       string(REGEX REPLACE "[^/]+" ".." _dots ${LLDB_FRAMEWORK_INSTALL_DIR})
       set_target_properties(${name} PROPERTIES
             RUNTIME_OUTPUT_DIRECTORY $<TARGET_FILE_DIR:liblldb>/Resources

source/Plugins/SymbolFile/PDB/CMakeLists.txt

-set(LLVM_PRIVATE_LINK_COMPONENTS
+set(LLVM_LINK_COMPONENTS
     DebugInfoPDB)
 
 add_lldb_library(lldbPluginSymbolFilePDB
   PDBASTParser.cpp
   SymbolFilePDB.cpp
   )

tools/argdumper/CMakeLists.txt

+include(${LLDB_PROJECT_ROOT}/cmake/LLDBDependencies.cmake)
+
 add_lldb_executable(lldb-argdumper INCLUDE_IN_FRAMEWORK
   argdumper.cpp
   )
 
-target_link_libraries(lldb-argdumper liblldb)
+if (LLDB_LINKER_SUPPORTS_GROUPS)
+  target_link_libraries(lldb-argdumper -Wl,--start-group ${LLDB_USED_LIBS} -Wl,--end-group)
+else()
+  target_link_libraries(lldb-argdumper ${LLDB_USED_LIBS})
+endif()
+llvm_config(lldb-argdumper ${LLVM_LINK_COMPONENTS})
+
 
 install(TARGETS lldb-argdumper
   RUNTIME DESTINATION bin)

tools/driver/CMakeLists.txt

+include(${LLDB_PROJECT_ROOT}/cmake/LLDBDependencies.cmake)
+
 add_lldb_executable(lldb
   Driver.cpp
   Platform.cpp
   )
 
 if ( CMAKE_SYSTEM_NAME MATCHES "Windows" )
   add_definitions( -DIMPORT_LIBLLDB )
 endif()
 
 # Add lldb dependency on lldb-server if we can use it.
 if ( LLDB_CAN_USE_LLDB_SERVER )
   add_dependencies(lldb lldb-server)
 endif()
 
 # Add lldb dependency on debugserver if we can use it.
 if ( LLDB_CAN_USE_DEBUGSERVER )
   add_dependencies(lldb debugserver)
 endif()
 
 target_link_libraries(lldb liblldb)
-# TODO: why isn't this done by add_lldb_executable?
-#target_link_libraries(lldb ${LLDB_USED_LIBS})
-#llvm_config(lldb ${LLVM_LINK_COMPONENTS})
+if ( CMAKE_SYSTEM_NAME MATCHES "Windows" )
+  # Windows does not have getopt support, so it relies on the one provided by
+  # liblldb. However, getopt is not a part of the liblldb interfact, so we have
+  # to link against the constituent libraries manually. Note that this is
+  # extremely scary as it introduces ODR violations, and it should go away as
+  # soon as possible.
+  target_link_libraries(lldb ${LLDB_USED_LIBS})
+endif()
 
 set_target_properties(lldb PROPERTIES VERSION ${LLDB_VERSION})
 
 install(TARGETS lldb
   RUNTIME DESTINATION bin)

tools/lldb-mi/CMakeLists.txt

+include(${LLDB_PROJECT_ROOT}/cmake/LLDBDependencies.cmake)
+
 set(LLDB_MI_SOURCES
   MICmdArgContext.cpp
   MICmdArgSet.cpp
   MICmdArgValBase.cpp
   MICmdArgValConsume.cpp
   MICmdArgValFile.cpp
   MICmdArgValListBase.cpp
   MICmdArgValListOfN.cpp