build: extract LLVM distribution target handling

[compnerd]

Summary

This extracts the LLVM distribution target handling into a support module. Extraction will enable us to restructure the builds to support multiple distribution configurations (e.g. developer and user) to permit us to build the development package and the user package at once.

[smeenai]

This looks good, but what were you envisioning the interface would look like for configuring multiple distributions? It'd be a lot easier to judge with that context.

cmake/modules/LLVMDistributionSupport.cmake

1

License header?

[smeenai]

This is technically a behavior change because with the old code, you wouldn't run any of the distribution code if LLVM_DISTRIBUTION_COMPONENTS was empty, even if LLVM_RUNTIME_DISTRIBUTION_COMPONENTS was non-empty. The new behavior seems more correct though.

[compnerd]

What I am imagining is basically having a variable which specifies the distribution targets, and having variables which will be constructed based upon those names (similar to how variables for the runtimes are passed today).

[smeenai]

Ah, so just having variables to hold the different distribution sets? Makes sense ... you'd need to adjust the CMake exporting logic, and I'm not quite sure how that'll play out yet, but we can see when we get to that.

This LGTM.

cmake/modules/LLVMDistributionSupport.cmake

1

Never mind, looks like we don't usually put the license header in build files.

[compnerd]

SVN r363440

CMakeLists.txt

 
 # This must be at the end of the LLVM root CMakeLists file because it must run
 # after all targets are created.
-if(LLVM_DISTRIBUTION_COMPONENTS)
-  if(LLVM_ENABLE_IDE)
-    message(FATAL_ERROR "LLVM_DISTRIBUTION_COMPONENTS cannot be specified with multi-configuration generators (i.e. Xcode or Visual Studio)")
-  endif()
-
-  add_custom_target(distribution)
-  add_custom_target(install-distribution)
-  add_custom_target(install-distribution-stripped)
-  foreach(target ${LLVM_DISTRIBUTION_COMPONENTS} ${LLVM_RUNTIME_DISTRIBUTION_COMPONENTS})
-    if(TARGET ${target})
-      add_dependencies(distribution ${target})
-    else()
-      message(SEND_ERROR "Specified distribution component '${target}' doesn't have a target")
-    endif()
-
-    if(TARGET install-${target})
-      add_dependencies(install-distribution install-${target})
-    else()
-      message(SEND_ERROR "Specified distribution component '${target}' doesn't have an install target")
-    endif()
-
-    if(TARGET install-${target}-stripped)
-      add_dependencies(install-distribution-stripped install-${target}-stripped)
-    else()
-      message(SEND_ERROR "Specified distribution component '${target}' doesn't have an install-stripped target."
-                         " Its installation target creation should be changed to use add_llvm_install_targets,"
-                         " or you should manually create the 'install-${target}-stripped' target.")
-    endif()
-  endforeach()
-endif()
+include(LLVMDistributionSupport)
+llvm_distribution_add_targets()
 
 # This allows us to deploy the Universal CRT DLLs by passing -DCMAKE_INSTALL_UCRT_LIBRARIES=ON to CMake
 if (MSVC AND CMAKE_HOST_SYSTEM_NAME STREQUAL "Windows" AND CMAKE_INSTALL_UCRT_LIBRARIES)

cmake/modules/LLVMDistributionSupport.cmake

+
+if(LLVM_DISTRIBUTION_COMPONENTS)
+  if(LLVM_ENABLE_IDE)
+    message(FATAL_ERROR "LLVM_DISTRIBUTION_COMPONENTS cannot be specified with multi-configuration generators (i.e. Xcode or Visual Studio)")
+  endif()
+endif()
+
+function(llvm_distribution_add_targets)
+  add_custom_target(distribution)
+  add_custom_target(install-distribution)
+  add_custom_target(install-distribution-stripped)
+
+  foreach(target ${LLVM_DISTRIBUTION_COMPONENTS}
+      ${LLVM_RUNTIME_DISTRIBUTION_COMPONENTS})
+    if(TARGET ${target})
+      add_dependencies(distribution ${target})
+    else()
+      message(SEND_ERROR "Specified distribution component '${target}' doesn't have a target")
+    endif()
+
+    if(TARGET install-${target})
+      add_dependencies(install-distribution install-${target})
+    else()
+      message(SEND_ERROR "Specified distribution component '${target}' doesn't have an install target")
+    endif()
+
+    if(TARGET install-${target}-stripped)
+      add_dependencies(install-distribution-stripped install-${target}-stripped)
+    else()
+      message(SEND_ERROR
+              "Specified distribution component '${target}' doesn't have an install-stripped target."
+              " Its installation target creation should be changed to use add_llvm_install_targets,"
+              " or you should manually create the 'install-${target}-stripped' target.")
+    endif()
+  endforeach()
+endif()