Define a new graph interaction API

1 files changed, 74 insertions, 0 deletions

diff --git a/chapter25/src/main/java/com/seaofnodes/simple/print/SimpleGraphAdapter.java b/chapter25/src/main/java/com/seaofnodes/simple/print/SimpleGraphAdapter.java
new file mode 100644
index 00000000..592abb5c
--- /dev/null
+++ b/chapter25/src/main/java/com/seaofnodes/simple/print/SimpleGraphAdapter.java
@@ -0,0 +1,74 @@
+package com.seaofnodes.simple.print;
+
+import com.seaofnodes.graph.GraphAdapter;
+import com.seaofnodes.graph.GraphSnapshot;
+import com.seaofnodes.graph.GraphSnapshot.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.node.Node;
+import com.seaofnodes.simple.type.TypeMem;
+import java.util.ArrayList;
+
+/** Chapter 25's view of the IR, including partially constructed parse-time graphs. */
+public class SimpleGraphAdapter extends GraphAdapter<Node> {
+    @Override protected int id(Node n) { return n._nid; }
+    @Override protected int nIns(Node n) { return n.nIns(); }
+    @Override protected Node in(Node n, int idx) { return n.in(idx); }
+    @Override protected int nOuts(Node n) { return n.nOuts(); }
+    @Override protected Node out(Node n, int idx) { return n.out(idx); }
+
+    private ArrayList<Edge> edges(Node n) {
+        var edges = new ArrayList<Edge>();
+        for( int i = 0; i < n.nIns(); i++ ) {
+            String name = n instanceof ScopeNode scope && i < scope._vars.size()
+                ? scope.var(i)._name : null;
+            edges.add(new Edge(i, ref(n.in(i)), role(n, i), name));
+        }
+        return edges;
+    }
+
+    @Override protected GraphSnapshot.Node desc(Node n) {
+        Projection proj = n instanceof Proj p
+            ? new Projection(n.nIns() == 0 ? 0 : ref(n.in(0)), p.idx()) : null;
+        String label = n.label();
+        return new GraphSnapshot.Node(n._nid, label == null ? n.getClass().getSimpleName() : label,
+                                      n._type == null ? null : n._type.toString(), kind(n), edges(n), proj);
+    }
+
+    private Kind kind(Node n) {
+        if( n instanceof ScopeNode ) return Kind.SCOPE;
+        if( n instanceof StartCUNode || n instanceof StopCUNode ) return Kind.UNIT;
+        if( n instanceof FunNode ) return Kind.FUN;
+        // Start inherits Loop for whole-program analysis, but is not a source loop.
+        if( n instanceof StartNode ) return Kind.CTRL;
+        if( n instanceof LoopNode ) return Kind.LOOP;
+        if( n instanceof RegionNode ) return Kind.REGION;
+        if( n instanceof PhiNode ) return Kind.PHI;
+        if( n instanceof CFGNode ) return Kind.CTRL;
+        return isMem(n) ? Kind.MEM : Kind.DATA;
+    }
+
+    private Role role(Node n, int i) {
+        if( n instanceof ScopeNode || n instanceof ConstantNode || n instanceof FunPtrNode ||
+            n instanceof CtrlNode || n instanceof XCtrlNode )
+            return Role.ASSOC;
+        if( n instanceof PhiNode )
+            return i == 0 ? Role.ASSOC : isMem(n) ? Role.MEM : Role.DATA;
+        if( n instanceof Proj )
+            return n instanceof CFGNode ? Role.CTRL : isMem(n) ? Role.MEM : Role.DATA;
+        if( n instanceof RegionNode && i == 0 ) return Role.ASSOC;
+        // Preserve known slot roles even when an input is not attached/typed yet.
+        if( i == 0 || n instanceof RegionNode || n instanceof StopNode ) return Role.CTRL;
+        if( n instanceof MemMergeNode ||
+            i == 1 && (n instanceof MemOpNode || n instanceof ReturnNode || n instanceof CallNode) ||
+            n instanceof EscapeNode && i >= 2 ) return Role.MEM;
+        Node def = n.in(i);
+        if( def instanceof CFGNode ) return Role.CTRL;
+        if( def != null && isMem(def) ) return Role.MEM;
+        return Role.DATA;
+    }
+
+    private boolean isMem(Node n) {
+        // These Phi subclasses are memory even before their first type computation.
+        return n instanceof MemPhiNode || n instanceof BulkMemPhiNode || n.isMem() || n._type instanceof TypeMem;
+    }
+}