Rewrite the CMake build to use explicit dependencies between libraries,

specified in the same file that the library itself is created. This is
more idiomatic for CMake builds, and also allows us to correctly specify
dependencies that are missed due to bugs in the GenLibDeps perl script,
or change from compiler to compiler. On Linux, this returns CMake to
a place where it can relably rebuild several targets of LLVM.

I have tried not to change the dependencies from the ones in the current
auto-generated file. The only places I've really diverged are in places
where I was seeing link failures, and added a dependency. The goal of
this patch is not to start changing the dependencies, merely to move
them into the correct location, and an explicit form that we can control
and change when necessary.

This also removes a serialization point in the build because we don't
have to scan all the libraries before we begin building various tools.
We no longer have a step of the build that regenerates a file inside the
source tree. A few other associated cleanups fall out of this.

This isn't really finished yet though. After talking to dgregor he urged
switching to a single CMake macro to construct libraries with both
sources and dependencies in the arguments. Migrating from the two macros
to that style will be a follow-up patch.

Also, llvm-config is still generated with GenLibDeps.pl, which means it
still has slightly buggy dependencies. The internal CMake
'llvm-config-like' macro uses the correct explicitly specified
dependencies however. A future patch will switch llvm-config generation
(when using CMake) to be based on these deps as well.

This may well break Windows. I'm getting a machine set up now to dig
into any failures there. If anyone can chime in with problems they see
or ideas of how to solve them for Windows, much appreciated.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136433 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 1 insertions, 27 deletions

diff --git a/cmake/modules/LLVM-Config.cmake b/cmake/modules/LLVM-Config.cmake
index a6286fe..d6b3124 100755
--- a/cmake/modules/LLVM-Config.cmake
+++ b/cmake/modules/LLVM-Config.cmake
@@ -152,7 +152,7 @@ function(explicit_map_components_to_libraries out_libs)
   set(processed)
   while( cursor LESS lst_size )
     list(GET expanded_components ${cursor} lib)
-    list(APPEND expanded_components ${MSVC_LIB_DEPS_${lib}})
+    list(APPEND expanded_components ${LLVM_LIB_DEPS_${lib}})
     # Remove duplicates at the front:
     list(REVERSE expanded_components)
     list(REMOVE_DUPLICATES expanded_components)
@@ -175,29 +175,3 @@ function(explicit_map_components_to_libraries out_libs)
   endforeach(c)
   set(${out_libs} ${result} PARENT_SCOPE)
 endfunction(explicit_map_components_to_libraries)
-
-
-# The library dependency data is contained in the file
-# LLVMLibDeps.cmake on this directory. It is automatically generated
-# by tools/llvm-config/CMakeLists.txt when the build comprises all the
-# targets and we are on a environment Posix enough to build the
-# llvm-config script. This, in practice, just excludes MSVC.
-
-# When you remove or rename a library from the build, be sure to
-# remove its file from lib/ as well, or the GenLibDeps.pl script will
-# include it on its analysis!
-
-# The format generated by GenLibDeps.pl
-
-# LLVMARMAsmPrinter.o: LLVMARMCodeGen.o libLLVMAsmPrinter.a libLLVMCodeGen.a libLLVMCore.a libLLVMSupport.a libLLVMTarget.a
-
-# is translated to:
-
-# set(MSVC_LIB_DEPS_LLVMARMAsmPrinter LLVMARMCodeGen LLVMAsmPrinter LLVMCodeGen LLVMCore LLVMSupport LLVMTarget)
-
-# It is necessary to remove the `lib' prefix and the `.a'.
-
-# This 'sed' script should do the trick:
-# sed -e s'#\.a##g' -e 's#libLLVM#LLVM#g' -e 's#: # #' -e 's#\(.*\)#set(MSVC_LIB_DEPS_\1)#' ~/llvm/tools/llvm-config/LibDeps.txt
-
-include(LLVMLibDeps)