[clang-scan-deps] initial outline of the tool that runs preprocessor to find

dependencies over a JSON compilation database

This commit introduces an outline for the clang-scan-deps tool that will be
used to implement fast dependency discovery phase using implicit modules for
explicit module builds.

The initial version of the tool works by computing non-modular header dependencies
for files in the compilation database without any optimizations
(i.e. without source minimization from r362459).
The tool spawns a number of worker threads to run the clang compiler workers in parallel.

The immediate goal for clang-scan-deps is to create a ClangScanDeps library
which will be used to build up this tool to use the source minimization and
caching multi-threaded filesystem to implement the optimized non-incremental
dependency scanning phase for a non-modular build. This will allow us to do
benchmarks and comparisons for performance that the minimization and caching give us

Differential Revision: https://reviews.llvm.org/D60233

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@363204 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 1 insertions, 0 deletions

diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 99524a5219..bcff4ba7e9 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -57,6 +57,7 @@ list(APPEND CLANG_TEST_DEPS
   clang-rename
   clang-refactor
   clang-diff
+  clang-scan-deps
   diagtool
   hmaptool
   )