doxygen switch to graphviz for prettier graphs and enable call graphs

CMakeLists.txt

@@ -205,5 +205,5 @@ if(DOXYGEN_FOUND)
   configure_file(${CMAKE_SOURCE_DIR}/docs/Doxyfile.in ${CMAKE_BINARY_DIR}/Doxyfile @ONLY)
   add_custom_target(docs ${DOXYGEN_EXECUTABLE} ${CMAKE_BINARY_DIR}/Doxyfile WORKING_DIRECTORY ${CMAKE_BINARY_DIR})
 else()
-  add_custom_target(docs COMMAND ${CMAKE_COMMAND} -E echo "Can't create docs, doxygen not installed \(try sudo apt-get install doxygen on Ubuntu and then rerun cmake\)" VERBATIM)
+  add_custom_target(docs COMMAND ${CMAKE_COMMAND} -E echo "Can't create docs, doxygen not installed \(try sudo apt-get install doxygen grpahviz on Ubuntu and then rerun cmake\)" VERBATIM)
 endif()

docs/Doxyfile.in

@@ -2100,7 +2100,7 @@ HIDE_UNDOC_RELATIONS   = YES
 # set to NO
 # The default value is: NO.
 
-HAVE_DOT               = NO
+HAVE_DOT               = YES
 
 # The DOT_NUM_THREADS specifies the number of dot invocations doxygen is allowed
 # to run in parallel. When set to 0 doxygen will base this on the number of
@@ -2216,7 +2216,7 @@ INCLUDED_BY_GRAPH      = YES
 # The default value is: NO.
 # This tag requires that the tag HAVE_DOT is set to YES.
 
-CALL_GRAPH             = NO
+CALL_GRAPH             = YES
 
 # If the CALLER_GRAPH tag is set to YES then doxygen will generate a caller
 # dependency graph for every global function or class method.
@@ -2227,7 +2227,7 @@ CALL_GRAPH             = NO
 # The default value is: NO.
 # This tag requires that the tag HAVE_DOT is set to YES.
 
-CALLER_GRAPH           = NO
+CALLER_GRAPH           = YES
 
 # If the GRAPHICAL_HIERARCHY tag is set to YES then doxygen will graphical
 # hierarchy of all classes instead of a textual one.

docs/INSTALLING.md

@@ -280,7 +280,7 @@ CXX=g++ CC=gcc PATH=~/pyston_deps/gcc-4.8.2-install/bin:$PATH:~/pyston_deps/ninj
 
 ### doxygen
 ```
-sudo apt-get install doxygen
+sudo apt-get install doxygen graphviz
 
 # then run cmake (see below) and invoke the docs target
 ninja docs