README: Improve and update the requirements list.

README

@@ -27,12 +27,14 @@ Distro packagers should only use released tarballs (no git snapshots).
 Requirements
 ------------
 
- - git
- - gcc (>= 4.0)
+Requirements for the C library:
+
+ - git (only needed when building from git)
+ - gcc (>= 4.0) or clang
  - make
- - autoconf >= 2.63
- - automake >= 1.11
- - libtool
+ - autoconf >= 2.63 (only needed when building from git)
+ - automake >= 1.11 (only needed when building from git)
+ - libtool (only needed when building from git)
  - pkg-config >= 0.22
  - libglib >= 2.34.0
  - libzip >= 0.10
@@ -40,7 +42,42 @@ Requirements
  - librevisa >= 0.0.20130812 (optional, used by some drivers)
  - libusb-1.0 >= 1.0.16 (optional, used by some drivers)
  - libftdi >= 0.16 or libftdi1 >= 1.0 (optional, used by some drivers)
+ - libgpib (optional, used by some drivers)
  - check >= 0.9.4 (optional, only needed to run unit tests)
+ - doxygen (optional, only needed for the C API docs)
+ - graphviz (optional, only needed for the C API docs)
+
+Requirements for the C++ bindings:
+
+ - libsigrok >= 0.3.0 (the libsigrok C library, see above)
+ - A C++ compiler with C++11 support (-std=c++11 option), e.g.
+   - g++ (>= 4.7)
+   - clang++ (>= 3.1)
+ - autoconf-archive (only needed when building from git)
+ - doxygen (required for building the bindings, not only for C++ API docs!)
+ - graphviz (optional, only needed for the C++ API docs)
+ - Python (2 or 3) executable (development files are not needed)
+ - glibmm-2.4 (>= 2.32.0)
+
+Requirements for the Python bindings:
+
+ - libsigrokxx >= 0.3.0 (the libsigrok C++ bindings, see above)
+ - Python >= 2.7 or Python >= 3 (including development files!)
+ - Python setuptools (for Python 2 or 3)
+ - pygobject >= 3.0.0 (for Python 2 or 3), a.k.a python-gi
+ - numpy (for Python 2 or 3)
+ - SWIG
+ - doxygen (optional, only needed for the Python API docs)
+ - graphviz (optional, only needed for the Python API docs)
+ - doxypy (optional, only needed for the Python API docs)
+
+Requirements for the Java bindings:
+
+ - libsigrokxx >= 0.3.0 (the libsigrok C++ bindings, see above)
+ - SWIG
+ - Java JDK (for JNI includes and the javac/jar binaries)
+ - doxygen (optional, only needed for the Java API docs)
+ - graphviz (optional, only needed for the Java API docs)
 
 
 Building and installing