[CMake] Add clang-bootstrap-deps target

Having this target allows other parts of the build system to add to the bootstrap dependencies without needing to be defined before the bootstrap targets are created.

This will specifically be used connect the builtins build from the LLVM runtimes directory as a dependency of the next build stage.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@284648 91177308-0d34-0410-b5e6-96231b3b80d8

CMakeLists.txt

@@ -484,6 +484,8 @@ endif()
 if (CLANG_ENABLE_BOOTSTRAP)
   include(ExternalProject)
 
+  add_custom_target(clang-bootstrap-deps DEPENDS clang)
+
   if(NOT CLANG_STAGE)
     set(CLANG_STAGE stage1)
   endif()
@@ -510,8 +512,8 @@ if (CLANG_ENABLE_BOOTSTRAP)
   set(BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/${NEXT_CLANG_STAGE}-bins/)
 
   # If the next stage is LTO we need to depend on LTO and possibly LLVMgold
-  if(BOOTSTRAP_LLVM_ENABLE_LTO OR LLVM_ENABLE_LTO)
-    set(LTO_DEP LTO)
+  if(BOOTSTRAP_LLVM_ENABLE_LTO OR LLVM_ENABLE_LTO AND NOT LLVM_BUILD_INSTRUMENTED)
+    add_dependencies(clang-bootstrap-deps LTO)
     if(APPLE)
       # on Darwin we need to set DARWIN_LTO_LIBRARY so that -flto will work
       # using the just-built compiler, and we need to override DYLD_LIBRARY_PATH
@@ -524,7 +526,7 @@ if (CLANG_ENABLE_BOOTSTRAP)
       set(LTO_LIBRARY -DDARWIN_LTO_LIBRARY=${LLVM_SHLIB_OUTPUT_INTDIR}/libLTO.dylib
         -DDYLD_LIBRARY_PATH=${LLVM_LIBRARY_OUTPUT_INTDIR})
     elseif(NOT WIN32)
-      list(APPEND LTO_DEP LLVMgold llvm-ar llvm-ranlib)
+      add_dependencies(clang-bootstrap-deps LLVMgold llvm-ar llvm-ranlib)
       set(LTO_AR -DCMAKE_AR=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-ar)
       set(LTO_RANLIB -DCMAKE_RANLIB=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-ranlib)
     endif()
@@ -535,7 +537,7 @@ if (CLANG_ENABLE_BOOTSTRAP)
     )
   add_custom_command(
     OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/${NEXT_CLANG_STAGE}-cleared
-    DEPENDS clang ${LTO_DEP}
+    DEPENDS clang-bootstrap-deps
     COMMAND ${CMAKE_COMMAND} -E remove_directory ${BINARY_DIR}
     COMMAND ${CMAKE_COMMAND} -E make_directory ${BINARY_DIR}
     COMMAND ${CMAKE_COMMAND} -E remove_directory ${STAMP_DIR}
@@ -562,8 +564,10 @@ if (CLANG_ENABLE_BOOTSTRAP)
     CMAKE_MAKE_PROGRAM
     CMAKE_OSX_ARCHITECTURES)
 
-  if(TARGET compiler-rt)
-    set(RUNTIME_DEP compiler-rt)
+  # We don't need to depend on compiler-rt if we're building instrumented
+  # because the next stage will use the same compiler used to build this stage.
+  if(TARGET compiler-rt AND NOT LLVM_BUILD_INSTRUMENTED)
+    add_dependencies(clang-bootstrap-deps compiler-rt)
   endif()
 
   set(COMPILER_OPTIONS
@@ -572,12 +576,12 @@ if (CLANG_ENABLE_BOOTSTRAP)
     -DCMAKE_ASM_COMPILER=${LLVM_RUNTIME_OUTPUT_INTDIR}/clang)
 
   if(BOOTSTRAP_LLVM_BUILD_INSTRUMENTED)
-    set(PGO_DEP llvm-profdata)
+    add_dependencies(clang-bootstrap-deps llvm-profdata)
     set(PGO_OPT -DLLVM_PROFDATA=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-profdata)
   endif()
 
   if(LLVM_BUILD_INSTRUMENTED)
-    set(PGO_DEP generate-profdata)
+    add_dependencies(clang-bootstrap-deps generate-profdata)
     set(PGO_OPT -DLLVM_PROFDATA_FILE=${CMAKE_CURRENT_BINARY_DIR}/utils/perf-training/clang.profdata)
     # Use the current tools for LTO instead of the instrumented ones
     list(APPEND _BOOTSTRAP_DEFAULT_PASSTHROUGH
@@ -591,8 +595,6 @@ if (CLANG_ENABLE_BOOTSTRAP)
 
     set(COMPILER_OPTIONS)
     set(LTO_LIBRARY)
-    set(RUNTIME_DEP) # Don't set runtime dependencies
-    set(LTO_DEP)     # Don't need to depend on LTO
     set(LTO_AR)
     set(LTO_RANLIB)
   endif()
@@ -627,7 +629,7 @@ if (CLANG_ENABLE_BOOTSTRAP)
   endforeach()
 
   ExternalProject_Add(${NEXT_CLANG_STAGE}
-    DEPENDS clang ${LTO_DEP} ${RUNTIME_DEP} ${PGO_DEP}
+    DEPENDS clang-bootstrap-deps
     PREFIX ${NEXT_CLANG_STAGE}
     SOURCE_DIR ${CMAKE_SOURCE_DIR}
     STAMP_DIR ${STAMP_DIR}