Noizu is GCC/Clang warnings formatter which lets you exclude specific paths or filenames to suppress their warnings from stderr compiler output. This can be handy for filtering warnings in code bases wich rely a lot on implementation defined behavior (e.g. DSP or SIMD libraries) or simply to separate own warnings from external ones.
Here is an example of an embedded C/C++ project which contains the CMSIS library. Running the unfiltered error log through Noizu returned a huge list of warnings.
-Wsign-conversion 2403 -Wconversion 324 -Wpedantic 16 -Wunused 7 -Wunused-parameter 6 -Wsign-compare 4 -Wstrict-aliasing 3 -Wattributes 2 -Wshadow 1 -Wunused-variable 1 2700+ lines of references...
Whereas filtering external libraries by path only showed a couple.
-Wunused 2 -Wunused-parameter 1 -Wsign-compare 1 -Wstrict-aliasing 1 -Wshadow 1 -Wunused-variable 1 -Wunused src/actual_warnings.cpp:7:11 src/actual_warnings.cpp:5:26 -Wunused-parameter src/actual_warnings.cpp:5:26 -Wsign-compare src/actual_warnings.cpp:11:9 -Wstrict-aliasing src/actual_warnings.cpp:16:5 -Wshadow src/actual_warnings.cpp:20:9 -Wunused-variable src/actual_warnings.cpp:7:11