CMake: Disable ENABLE_EXPORTS for executables with MSVC

The MSVC linker won't produce a .lib file for an executable that doesn't
export anything, and LLVM doesn't maintain dllexport annotations or .def
files listing all C++ symbols. It also doesn't support exporting all
symbols, like binutils ld.

CMake 3.2 changed the Ninja generator to list both the .exe and .lib
files as outputs of executable build targets. Ninja would always re-link
executables with ENABLE_EXPORTS because the .lib output file was not
present, and therefore the target was out of date.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232662 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/CMakeLists.txt b/CMakeLists.txt
index cfbf956..b91ba15 100644 (file)
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -557,7 +557,7 @@ if( ${CMAKE_SYSTEM_NAME} MATCHES SunOS )
 endif( ${CMAKE_SYSTEM_NAME} MATCHES SunOS )
 
 # Make sure we don't get -rdynamic in every binary. For those that need it,
-# use set_target_properties(target PROPERTIES ENABLE_EXPORTS 1)
+# use export_executable_symbols(target).
 set(CMAKE_SHARED_LIBRARY_LINK_CXX_FLAGS "")
 
 include(AddLLVM)

diff --git a/cmake/modules/AddLLVM.cmake b/cmake/modules/AddLLVM.cmake
index de542f5..8389793 100644 (file)
--- a/cmake/modules/AddLLVM.cmake
+++ b/cmake/modules/AddLLVM.cmake
@@ -490,6 +490,12 @@ macro(add_llvm_executable name)
   endif( LLVM_COMMON_DEPENDS )
 endmacro(add_llvm_executable name)
 
+function(export_executable_symbols target)
+  if (NOT MSVC) # MSVC's linker doesn't support exporting all symbols.
+    set_target_properties(${target} PROPERTIES ENABLE_EXPORTS 1)
+  endif()
+endfunction()
+
 
 set (LLVM_TOOLCHAIN_TOOLS
   llvm-ar

diff --git a/examples/ExceptionDemo/CMakeLists.txt b/examples/ExceptionDemo/CMakeLists.txt
index 9cadd94..2a7667d 100644 (file)
--- a/examples/ExceptionDemo/CMakeLists.txt
+++ b/examples/ExceptionDemo/CMakeLists.txt
@@ -15,4 +15,4 @@ add_llvm_example(ExceptionDemo
   ExceptionDemo.cpp
   )
 
-set_target_properties(ExceptionDemo PROPERTIES ENABLE_EXPORTS 1)
+export_executable_symbols(ExceptionDemo)

diff --git a/tools/bugpoint/CMakeLists.txt b/tools/bugpoint/CMakeLists.txt
index d71e097..daf502e 100644 (file)
--- a/tools/bugpoint/CMakeLists.txt
+++ b/tools/bugpoint/CMakeLists.txt
@@ -31,7 +31,7 @@ add_llvm_tool(bugpoint
   ToolRunner.cpp
   bugpoint.cpp
   )
-set_target_properties(bugpoint PROPERTIES ENABLE_EXPORTS 1)
+export_executable_symbols(bugpoint)
 
 if(WITH_POLLY AND LINK_POLLY_INTO_TOOLS)
   target_link_libraries(bugpoint Polly)

diff --git a/tools/llc/CMakeLists.txt b/tools/llc/CMakeLists.txt
index 484ff40..dcbcf9d 100644 (file)
--- a/tools/llc/CMakeLists.txt
+++ b/tools/llc/CMakeLists.txt
@@ -17,4 +17,4 @@ set(LLVM_NO_DEAD_STRIP 1)
 add_llvm_tool(llc
   llc.cpp
   )
-set_target_properties(llc PROPERTIES ENABLE_EXPORTS 1)
+export_executable_symbols(llc)

diff --git a/tools/lli/CMakeLists.txt b/tools/lli/CMakeLists.txt
index 463c853..aad8367 100644 (file)
--- a/tools/lli/CMakeLists.txt
+++ b/tools/lli/CMakeLists.txt
@@ -39,4 +39,4 @@ add_llvm_tool(lli
   RemoteTarget.cpp
   RemoteTargetExternal.cpp
   )
-set_target_properties(lli PROPERTIES ENABLE_EXPORTS 1)
+export_executable_symbols(llvm-stress)

diff --git a/tools/llvm-stress/CMakeLists.txt b/tools/llvm-stress/CMakeLists.txt
index 106ced1..d5c10e1 100644 (file)
--- a/tools/llvm-stress/CMakeLists.txt
+++ b/tools/llvm-stress/CMakeLists.txt
@@ -7,4 +7,4 @@ set(LLVM_LINK_COMPONENTS
 add_llvm_tool(llvm-stress
   llvm-stress.cpp
   )
-set_target_properties(llvm-stress PROPERTIES ENABLE_EXPORTS 1)
+export_executable_symbols(llvm-stress)

diff --git a/tools/opt/CMakeLists.txt b/tools/opt/CMakeLists.txt
index 12dc4f0..5f82522 100644 (file)
--- a/tools/opt/CMakeLists.txt
+++ b/tools/opt/CMakeLists.txt
@@ -31,7 +31,7 @@ add_llvm_tool(opt
   PrintSCC.cpp
   opt.cpp
   )
-set_target_properties(opt PROPERTIES ENABLE_EXPORTS 1)
+export_executable_symbols(opt)
 
 if(WITH_POLLY AND LINK_POLLY_INTO_TOOLS)
   target_link_libraries(opt Polly)