[clang] 0135bc9 - [clang] Always execute multi-stage install steps

[Shoaib Meenai via cfe-commits]

Author: Shoaib Meenai
Date: 2021-03-25T11:36:00-07:00
New Revision: 0135bc996d82ff68677820c421b4d666590e4f31

URL: https://github.com/llvm/llvm-project/commit/0135bc996d82ff68677820c421b4d666590e4f31
DIFF: https://github.com/llvm/llvm-project/commit/0135bc996d82ff68677820c421b4d666590e4f31.diff

LOG: [clang] Always execute multi-stage install steps

We want installs to be executed even if binaries haven't changed, e.g.
so that we can install to multiple places. This is consistent with how
non-multi-stage install targets (e.g. the regular install-distribution
target) behave.

Reviewed By: phosek

Differential Revision: https://reviews.llvm.org/D99321

Added: 
    

Modified: 
    clang/CMakeLists.txt

Removed: 
    


################################################################################
diff  --git a/clang/CMakeLists.txt b/clang/CMakeLists.txt
index aa38110b6d22..6535f84edbb7 100644
--- a/clang/CMakeLists.txt
+++ b/clang/CMakeLists.txt
@@ -867,10 +867,23 @@ if (CLANG_ENABLE_BOOTSTRAP)
     # exclude from main target
     set_target_properties(${NEXT_CLANG_STAGE} PROPERTIES _EP_${target}_EXCLUDE_FROM_MAIN On)
 
+    # Install targets have side effects, so we always want to execute them.
+    # "install" is reserved by CMake and can't be used as a step name for
+    # ExternalProject_Add_Step, so we can match against "^install-" instead of
+    # "^install" to get a tighter match. CMake's installation scripts already
+    # skip up-to-date files, so there's no behavior change if you install to the
+    # same destination multiple times.
+    if(target MATCHES "^install-")
+      set(step_always ON)
+    else()
+      set(step_always OFF)
+    endif()
+
     ExternalProject_Add_Step(${NEXT_CLANG_STAGE} ${target}
       COMMAND ${CMAKE_COMMAND} --build <BINARY_DIR> --target ${target}
       COMMENT "Performing ${target} for '${NEXT_CLANG_STAGE}'"
       DEPENDEES configure
+      ALWAYS ${step_always}
       USES_TERMINAL 1
     )