CMake: Automatic regeneration of the library dependencies file.

It doesn't stop or reconfigure the build, though, so the user will see
a broken build that magically succeeds at the next attempt. It is
technically possible to halt the build with a helpful message, and
even to automatically restart the build using the new dependencies as
it we did when llvm-config was used by cmake for learning
dependencies. This is left on the TODO list.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79004 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/llvm-config/CMakeLists.txt b/tools/llvm-config/CMakeLists.txt
index 4873794..b029663 100644
--- a/tools/llvm-config/CMakeLists.txt
+++ b/tools/llvm-config/CMakeLists.txt
@@ -124,4 +124,26 @@
   WORLD_READ WORLD_EXECUTE
   DESTINATION bin)
 
+
+# Regeneration of library dependencies.
+
+# See the comments at the end of cmake/modules/LLVMConfig.cmake for
+# notes and guidelines.
+
+set(LLVMLibDeps ${LLVM_MAIN_SRC_DIR}/cmake/modules/LLVMLibDeps.cmake)
+set(LLVMLibDeps_TMP ${CMAKE_CURRENT_BINARY_DIR}/LLVMLibDeps.cmake.tmp)
+
+add_custom_command(OUTPUT ${LLVMLibDeps_TMP}
+  COMMAND sed -e s'@\\.a@@g' -e 's@libLLVM@LLVM@g' -e 's@: @ @' -e 's@\\\(.*\\\)@set\(MSVC_LIB_DEPS_\\1\)@' ${FINAL_LIBDEPS} > ${LLVMLibDeps_TMP}
+  COMMAND ${CMAKE_COMMAND} -E copy_if_different ${LLVMLibDeps_TMP} ${LLVMLibDeps}
+  DEPENDS ${FINAL_LIBDEPS}
+  COMMENT "Updating cmake library dependencies file ${LLVMLibDeps}"
+  )
+
+if( LLVM_TARGETS_TO_BUILD STREQUAL LLVM_ALL_TARGETS )
+  add_custom_target(llvmlibdeps.target ALL DEPENDS ${LLVMLibDeps_TMP})
+  add_dependencies(llvmlibdeps.target llvm-config.target)
+  set(LLVM_COMMON_DEPENDS ${LLVM_COMMON_DEPENDS} llvmlibdeps.target)
+endif()
+
 set(LLVM_COMMON_DEPENDS ${LLVM_COMMON_DEPENDS} PARENT_SCOPE)