Use the ast edge label when building the ast node label

The C PrintAST library now includes the edge name in the AST Viewer
tree.

Author: aeisenberg

extensions/ql-vscode/src/contextual/astBuilder.ts

@@ -45,17 +45,18 @@ export default class AstBuilder {
     const parentToChildren = new Map<BqrsId, BqrsId[]>();
     const childToParent = new Map<BqrsId, BqrsId>();
     const astOrder = new Map<BqrsId, number>();
+    const tupleTargetLabels = new Map<BqrsId, string>();
     const roots = [];
 
     // Build up the parent-child relationships
     edgeTuples.tuples.forEach(tuple => {
-      const [source, target, tupleType, orderValue] = tuple as [EntityValue, EntityValue, string, string];
+      const [source, target, tupleType, value] = tuple as [EntityValue, EntityValue, string, string];
       const sourceId = source.id!;
       const targetId = target.id!;
 
       switch (tupleType) {
         case 'semmle.order':
-          astOrder.set(targetId, Number(orderValue));
+          astOrder.set(targetId, Number(value));
           break;
 
         case 'semmle.label': {
@@ -65,6 +66,11 @@ export default class AstBuilder {
             parentToChildren.set(sourceId, children = []);
           }
           children.push(targetId);
+
+          // ignore values that indicate a numeric order.
+          if (!Number.isFinite(Number(value))) {
+            tupleTargetLabels.set(targetId, value);
+          }
           break;
         }
 
@@ -84,9 +90,10 @@ export default class AstBuilder {
           break;
 
         case 'semmle.label': {
+          const label = [tupleTargetLabels.get(id), value ?? entity.label].filter(e => e).join(': ');
           const item = {
             id,
-            label: value ?? entity.label,
+            label,
             location: entity.url,
             fileLocation: fileRangeFromURI(entity.url, this.db),
             children: [] as ChildAstItem[],

extensions/ql-vscode/src/vscode-tests/no-workspace/contextual/astBuilder.test.ts

@@ -65,6 +65,35 @@ describe('AstBuilder', () => {
     )).to.deep.eq(expectedRoots);
   });
 
+  it('should build the AST children', async () => {
+    // just test one of the children to make sure that the structure is right
+    const astBuilder = createAstBuilder();
+    const roots = await astBuilder.getRoots();
+
+    expect(roots[0].children[1].parent).to.eq(roots[0]);
+    // break the recursion
+    (roots[0].children[1] as any).parent = undefined;
+    (roots[0].children[1] as any).children = undefined;
+
+    const child = {
+      children: undefined,
+      fileLocation: undefined,
+      id: 26367,
+      label: 'body: [Block] { ... }',
+      location: {
+        endColumn: 1,
+        endLine: 22,
+        startColumn: 1,
+        startLine: 20,
+        uri: 'file:/opt/src/arch/sandbox/lib/interrupts.c'
+      },
+      order: 2,
+      parent: undefined
+    };
+
+    expect(roots[0].children[1]).to.deep.eq(child);
+  });
+
   it('should fail when graphProperties are not correct', async () => {
     overrides.graphProperties = {
       tuples: [