CScout is a source code analyzer and refactoring browser for
collections of C programs.  It can process workspaces of multiple
projects (we define a project as a collection of C source files
that are linked together) mapping the complexity introduced by the
C preprocessor back into the original C source code files.  CScout
takes advantage of modern hardware advances (fast processors and
large memory capacities) to analyze C source code beyond the level
of detail and accuracy provided by  current compilers and linkers.
The analysis CScout performs takes into account the identifier
scopes introduced by the C preprocessor and the C language proper
scopes and namespaces.  CScout has already been applied on projects
ranging from tens of thousands of lines, like the FreeBSD and
Linux kernels, and the Apache web server.

See also: https://github.com/dspinellis/cscout