thread worker code and better error handling
This commit extracts out the code that will powers the fast scanning
worker into a new file in a new DependencyScanning library. The error
and output handling is improved so that the clients can gather
errors/results from the worker directly.
Differential Revision: https://reviews.llvm.org/D63681
llvm-svn: 364474
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
llvm-svn: 363204
Alex Lorenz