[llvm] 5905e69 - [runtimes] Handle interface targets in runtimes distribution components

[Louis Dionne via llvm-commits]

Author: Louis Dionne
Date: 2022-08-23T08:55:58-04:00
New Revision: 5905e699342fd476d7eb9e35db5d84248a7e9156

URL: https://github.com/llvm/llvm-project/commit/5905e699342fd476d7eb9e35db5d84248a7e9156
DIFF: https://github.com/llvm/llvm-project/commit/5905e699342fd476d7eb9e35db5d84248a7e9156.diff

LOG: [runtimes] Handle interface targets in runtimes distribution components

As reported in [1], cxx-headers is not a valid distribution target
because it is an interface target in CMake. This breaks the most
basic MultiDistributionExample of the runtimes build.

This patch handles interface targets by getting rid of the assumption
that all distribution components have a target associated to them. It
is valid for a distribution component to only have a `install-FOO`
target.

In the case where only `cxx-headers` is provided as a distribution
component, `ninja toolchain-distribution` will not build anything
after this patch, since there is effectively nothing to build for
the `cxx-headers` target. However, running `ninja install-toolchain-distribution`
will build everything, as expected.

[1]: https://discord.com/channels/636084430946959380/636732894974312448/1010013287464828968

Differential Revision: https://reviews.llvm.org/D132387

Added: 
    

Modified: 
    llvm/cmake/modules/LLVMDistributionSupport.cmake
    llvm/runtimes/CMakeLists.txt

Removed: 
    


################################################################################
diff  --git a/llvm/cmake/modules/LLVMDistributionSupport.cmake b/llvm/cmake/modules/LLVMDistributionSupport.cmake
index a2fe69df1e7e6..526f36dcda830 100644
--- a/llvm/cmake/modules/LLVMDistributionSupport.cmake
+++ b/llvm/cmake/modules/LLVMDistributionSupport.cmake
@@ -260,10 +260,10 @@ function(llvm_distribution_add_targets)
     add_custom_target(install-${distribution_target}-stripped)
 
     foreach(target ${distribution_components})
+      # Note that some distribution components may not have an actual target, but only an install-FOO target.
+      # This happens for example if a target is an INTERFACE target.
       if(TARGET ${target})
         add_dependencies(${distribution_target} ${target})
-      else()
-        message(SEND_ERROR "Specified distribution component '${target}' doesn't have a target")
       endif()
 
       if(TARGET install-${target})

diff  --git a/llvm/runtimes/CMakeLists.txt b/llvm/runtimes/CMakeLists.txt
index d9041216beb5f..e10962022354b 100644
--- a/llvm/runtimes/CMakeLists.txt
+++ b/llvm/runtimes/CMakeLists.txt
@@ -214,7 +214,7 @@ function(runtime_default_target)
   endforeach()
   foreach(component ${LLVM_RUNTIME_DISTRIBUTION_COMPONENTS})
     if(NOT ${component} IN_LIST SUB_COMPONENTS)
-      list(APPEND extra_targets ${component} install-${component} install-${component}-stripped)
+      list(APPEND extra_targets install-${component} install-${component}-stripped)
     endif()
   endforeach()