From a37005a1d4924f6301dac1f6a83c00772f7f30e6 Mon Sep 17 00:00:00 2001
From: Jakob Olesen <jolesen@mozilla.com>
Date: Tue, 9 Feb 2016 08:11:20 -0800
Subject: [PATCH] Enable inheritance diagrams.

---
 cranelift/docs/conf.py     |  9 +++++++++
 cranelift/docs/metaref.rst | 17 ++++++++++++-----
 meta/cretonne/types.py     | 21 ++++++++++-----------
 3 files changed, 31 insertions(+), 16 deletions(-)

diff --git a/cranelift/docs/conf.py b/cranelift/docs/conf.py
index 0b7f7667d8..c4ab93eff0 100644
--- a/cranelift/docs/conf.py
+++ b/cranelift/docs/conf.py
@@ -38,6 +38,8 @@ extensions = [
     'sphinx.ext.todo',
     'sphinx.ext.mathjax',
     'sphinx.ext.ifconfig',
+    'sphinx.ext.graphviz',
+    'sphinx.ext.inheritance_diagram',
     'cton_domain',
     'cton_lexer',
 ]
@@ -293,3 +295,10 @@ texinfo_documents = [
 
 # If true, do not generate a @detailmenu in the "Top" node's menu.
 #texinfo_no_detailmenu = False
+
+
+# -- Options for Graphviz -------------------------------------------------
+
+graphviz_output_format = 'svg'
+
+inheritance_graph_attrs = dict(rankdir='TD')
diff --git a/cranelift/docs/metaref.rst b/cranelift/docs/metaref.rst
index 42a471cc93..8cdece065c 100644
--- a/cranelift/docs/metaref.rst
+++ b/cranelift/docs/metaref.rst
@@ -13,21 +13,28 @@ directory that has a global variable called ``instructions``. The basic
 Cretonne instruction set described in :doc:`langref` is defined by the Python
 module :mod:`cretonne.instrs`.
 
+.. module:: cretonne
+
 Types
 =====
 
 Concrete value types are represented as instances of :class:`cretonne.Type`. There are
 subclasses to represent scalar and vector types.
 
-.. autoclass:: cretonne.Type
-.. autoclass:: cretonne.ScalarType
+.. inheritance-diagram:: Type ScalarType VectorType IntType FloatType
+    :parts: 1
+.. autoclass:: Type
+.. autoclass:: ScalarType
     :members:
-.. autoclass:: cretonne.VectorType
+.. autoclass:: VectorType
     :members:
-.. autoclass:: cretonne.IntType
+.. autoclass:: IntType
     :members:
-.. autoclass:: cretonne.FloatType
+.. autoclass:: FloatType
     :members:
+
+Predefined types
+----------------
 .. automodule:: cretonne.types
     :members:
 
diff --git a/meta/cretonne/types.py b/meta/cretonne/types.py
index 27a74aec67..3d369a60e4 100644
--- a/meta/cretonne/types.py
+++ b/meta/cretonne/types.py
@@ -1,17 +1,21 @@
-"""Predefined types."""
+"""
+The cretonne.types module predefines all the Cretonne scalar types.
+"""
 
 from . import ScalarType, IntType, FloatType
 
+#: Boolean.
 bool = ScalarType('bool', 0,
         """
         A boolean value that is either true or false.
         """)
 
-i8  = IntType(8)
-i16 = IntType(16)
-i32 = IntType(32)
-i64 = IntType(64)
+i8  = IntType(8)  #: 8-bit int.
+i16 = IntType(16) #: 16-bit int.
+i32 = IntType(32) #: 32-bit int.
+i64 = IntType(64) #: 64-bit int.
 
+#: IEEE single precision.
 f32 = FloatType(32,
         """
         A 32-bit floating point type represented in the IEEE 754-2008 *binary32*
@@ -19,15 +23,10 @@ f32 = FloatType(32,
         C implementations.
         """)
 
+#: IEEE double precision.
 f64 = FloatType(64,
         """
         A 64-bit floating point type represented in the IEEE 754-2008 *binary64*
         interchange format. This corresponds to the :c:type:`double` type in
         most C implementations.
         """)
-
-i8x16 = i8.by(16)
-
-f32x4 = f32.by(4)
-f64x2 = f64.by(2)
-