[llvm] r274270 - [CMake] Module builds depend on target intrinsics_gen to be built first.

[Vassil Vassilev via llvm-commits]

Author: vvassilev
Date: Thu Jun 30 15:35:56 2016
New Revision: 274270

URL: http://llvm.org/viewvc/llvm-project?rev=274270&view=rev
Log:
[CMake] Module builds depend on target intrinsics_gen to be built first.

When compiling with modules, header A and B can be in the same module M.
B depends on intrinsics_gen and A doesn't. Compiling a source file #include-ing
header A, we implicitly request module M to be built. It puts header A and B in
the same TU and tries to build them. Since B depends on intrinsics_gen (which
might not be built yet) we run into build failures.

This should fix our modules buildbot.

Patch reviewed by Chris Bieneman.

Modified:
    llvm/trunk/CMakeLists.txt

Modified: llvm/trunk/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/CMakeLists.txt?rev=274270&r1=274269&r2=274270&view=diff
==============================================================================
--- llvm/trunk/CMakeLists.txt (original)
+++ llvm/trunk/CMakeLists.txt Thu Jun 30 15:35:56 2016
@@ -700,6 +700,15 @@ add_subdirectory(lib/TableGen)
 
 add_subdirectory(utils/TableGen)
 
+# Force target to be built as soon as possible. Clang modules builds depend
+# header-wise on it as they ship all headers from the umbrella folders. Building
+# an entire module might include header, which depends on intrinsics_gen. This
+# should be right after LLVMSupport and LLVMTableGen otherwise we introduce a
+# circular dependence.
+if (LLVM_ENABLE_MODULES)
+  list(APPEND LLVM_COMMON_DEPENDS intrinsics_gen)
+endif(LLVM_ENABLE_MODULES)
+
 add_subdirectory(include/llvm)
 
 add_subdirectory(lib)