Improved documentation

README.md

@@ -34,12 +34,12 @@ compiling a given program.
 
 Let me briefly explain how to use some of the experiments.
 
-## `ast-walker`
+## `ast-dumper` & `ast-walker`
 
-This programs walks an abstract syntax tree. It follows the
-implementation given in [this blog
-post](http://bastian.rieck.ru/blog/posts/2015/baby_steps_libclang_ast).
-To use it, you require the creation of an abstract syntax tree:
+These programs walk an abstract syntax tree. They roughly follow the
+implementation given in [this blog post](http://bastian.rieck.ru/blog/posts/2015/baby_steps_libclang_ast).
+To use one of them (I am exemplarily demonstrating `ast-walker`),
+you require the creation of an abstract syntax tree:
 
     $ clang++ -std=c++11 -emit-ast ../examples/tuple.cc
     $ ./ast-walker tuple.ast
@@ -106,6 +106,51 @@ This should result in an output similar to this:
     - FieldDecl (c)
     - FieldDecl (d)
 
+## `count-function-extents`
+
+Getting this program to run can be a *tiny* bit more trickier. We should
+supply it with the default paths required by `clang++`. To determine
+them, call  
+
+    $ clang++ -v -c FILE
+
+where `FILE` is a source file of your choice. The resulting output
+should contain the line 
+
+    #include <...> search starts here:
+
+and a list of paths. Copy them and put them into one command-line
+variable, like so:
+
+    $ export CPLUS_INCLUDE_PATH=/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/7.1.1/../../../../include/c++/7.1.1:/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/7.1.1/../../../../include/c++/7.1.1/x86_64-pc-linux-gnu:/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/7.1.1/../../../../include/c++/7.1.1/backward:/usr/local/include:/usr/bin/../lib/clang/4.0.1/include
+
+Afterwards, you can call the program on a test executable:
+
+    $ ./count-function-extents ../examples/functions.cc
+
+This should result in the following output:
+
+    Obtained 0 compile commands
+      theAnswerToLifeTheUniverseAndEverything: 3
+      sum: 3
+      square: 3
+      cube: 3
+      factorial: 6
+      fibonacci: 14
+
+You can also call the function for any executable specified in
+a `compile_commands.json` data base:
+
+    $ ./count-function-extents ../count-function-extents.cc
+    Parsing /home/brieck/Projects/libclang-experiments/count-function-extents.cc...
+    Obtained 1 compile commands
+      getCursorSpelling: 7
+      resolvePath: 17
+      functionVisitor: 24
+      main: 74
+
+I am sure that these programs could be easily improved. I look forward
+to your changes!
 
 # Additional information