docs: Add profiling for compile times

docs/developer/index.rst

@@ -7,4 +7,6 @@ Developer Manual
    Source Code Documentation <apidocs.rst>
    Building the Documentation <build_doc.rst>
    Code Style Guide <style.rst>
-   Contributing <contrib.rst>
+   Contributing <contrib.rst>
+   Profiling <profiling.rst>
+

docs/developer/profiling.rst

@@ -0,0 +1,24 @@
+Profiling
+=========
+
+Compile Times
+-------------
+1. Select a clang compiler
+2. Configure and include `-ftime-trace` in your CXX FLAGS (this works with clang+cuda).
+3. Clone and build https://github.com/aras-p/ClangBuildAnalyzer. Put the binary directory in your `PATH`.
+4. Compile Kokkos and KokkosKernels
+5. Create a directory called `ftime-trace-artifacts` in your build directory
+6. Copy the json files you care about in this directory, for example:
+
+.. code-block::
+
+  cp ./{sparse,blas}/unit_test/CMakeFiles/*.dir/backends/*.json ftime-trace-artifacts/
+
+7. Run `ClangBuildAnalyzer:
+
+.. code-block::
+
+  ClangBuildAnalyzer --all ftime-trace-artifacts/ profile.txt
+  ClangBuildAnalyzer --analyze profile.txt > analyze.txt
+
+8. Open `analyze.txt`