refactor(managed): centralize MemberRef row facts

src/dotnet/ManagedArtifactInspector.test.ts

@@ -583,6 +583,35 @@ describe("managed artifact coded indexes", () => {
   }, 30_000);
 });
 
+it.each([false, true])(
+  "resolves an attribute type without reading malformed constructor heaps (bad name %s)",
+  (badName) => {
+    const bytes = buildManagedPeFixture();
+    const layout = metadataLayoutFor(bytes);
+    const row = layout.table(10)!;
+    const nameColumn = row.offset + layout.codedIndexSize("MemberRefParent");
+    const signatureColumn = nameColumn + layout.stringIndexSize;
+    if (badName) {
+      if (layout.stringIndexSize === 2) bytes.writeUInt16LE(0xffff, nameColumn);
+      else bytes.writeUInt32LE(0xffffffff, nameColumn);
+    }
+    if (layout.blobIndexSize === 2)
+      bytes.writeUInt16LE(0xffff, signatureColumn);
+    else bytes.writeUInt32LE(0xffffffff, signatureColumn);
+
+    const result = inspectManagedArtifactBytes(
+      bytes,
+      managedPeFixtureTarget(bytes),
+    );
+    expect(result.attributes[0]).toMatchObject({
+      constructor_token: "0x0a000001",
+      type_name: "System.Runtime.Versioning.TargetFrameworkAttribute",
+      decoded_fixed_string: ".NETCoreApp,Version=v8.0",
+    });
+    expect(result.coverage).toEqual({ state: "complete", issues: [] });
+  },
+);
+
 describe("managed artifact reference inventory", () => {
   it("qualifies local custom-attribute names with their enclosing types", () => {
     const bytes = buildManagedPeFixture({

src/dotnet/ManagedMemberInspector.test.ts

@@ -571,6 +571,56 @@ const genericRef = Buffer.from([0x30, 0x01, 0x00, 0x01]);
 // GENERIC, one generic parameter, no parameters, void.
 const genericDef = Buffer.from([0x10, 0x01, 0x00, 0x01]);
 
+it.each([
+  { badName: true, parent: 0, expectedHeap: "#Strings" },
+  { badName: false, parent: 0, expectedHeap: "#Blob" },
+  { badName: true, parent: 17, expectedHeap: "#Strings" },
+  { badName: false, parent: 17, expectedHeap: "#Blob" },
+])(
+  "reports $expectedHeap before invalid MemberRef parent $parent (bad name $badName)",
+  ({ badName, parent, expectedHeap }) => {
+    const bytes = buildManagedPeFixture({ memberRefParentRaw: parent });
+    const pe = readManagedPeLayout(bytes);
+    if (pe.cli === null) throw new Error("fixture has no CLI header");
+    const { rva, size } = pe.cli.metadata;
+    const layout = readManagedMetadataLayout(
+      bytes,
+      pe.rvaToOffset(rva, size, "metadata"),
+      size,
+    );
+    const nameColumn =
+      metadataRowOffset(layout, 10, 1) +
+      layout.codedIndexSize("MemberRefParent");
+    if (badName) {
+      if (layout.stringIndexSize === 2) bytes.writeUInt16LE(0xffff, nameColumn);
+      else bytes.writeUInt32LE(0xffffffff, nameColumn);
+    }
+    const signatureColumn = nameColumn + layout.stringIndexSize;
+    if (layout.blobIndexSize === 2)
+      bytes.writeUInt16LE(0xffff, signatureColumn);
+    else bytes.writeUInt32LE(0xffffffff, signatureColumn);
+    const result = inspectManagedMembersBytes(
+      bytes,
+      managedPeFixtureTarget(bytes),
+    );
+    expect(result.member_refs).toEqual([]);
+    expect(result.coverage.state).toBe("partial");
+    expect(
+      result.coverage.issues.filter(
+        ({ scope }) =>
+          scope === "metadata.#Strings" ||
+          scope === "metadata.#Blob" ||
+          scope === "metadata.MemberRef:0x0a000001",
+      ),
+    ).toEqual([
+      expect.objectContaining({
+        code: "invalid-heap-index",
+        scope: `metadata.${expectedHeap}`,
+      }),
+    ]);
+  },
+);
+
 describe("managed TypeSpec declaring names", () => {
   it("names a generic TypeSpec parent by its generic type and leaves other TypeSpecs unknown", () => {
     // GENERICINST CLASS TypeRef(1) <string>
@@ -956,6 +1006,55 @@ describe("managed MethodSpec call targets", () => {
   });
 });
 
+it("reads MethodSpec arity from an unnamed MemberRef independently of parent admission", () => {
+  const bytes = buildManagedPeFixture({
+    memberRefSignature: genericRef,
+    memberRefParentRaw: 17,
+    methodSpecMethods: [(1 << 1) | 1],
+    methodSpecInstantiation: Buffer.from([0x0a, 0x01, 0x0e]),
+    ilBody: tokenBody([[call, 0x2b00_0001]]),
+  });
+  const pe = readManagedPeLayout(bytes);
+  if (pe.cli === null) throw new Error("fixture has no CLI header");
+  const { rva, size } = pe.cli.metadata;
+  const layout = readManagedMetadataLayout(
+    bytes,
+    pe.rvaToOffset(rva, size, "metadata"),
+    size,
+  );
+  const nameColumn =
+    metadataRowOffset(layout, 10, 1) + layout.codedIndexSize("MemberRefParent");
+  if (layout.stringIndexSize === 2) bytes.writeUInt16LE(0xffff, nameColumn);
+  else bytes.writeUInt32LE(0xffffffff, nameColumn);
+  const result = inspectManagedMembersBytes(
+    bytes,
+    managedPeFixtureTarget(bytes),
+  );
+  expect(result.member_refs).toEqual([]);
+  expect(result.call_edges).toMatchObject([
+    {
+      target_token: "0x2b000001",
+      target_kind: "method-spec",
+      target_name: null,
+      target_declaring_type: null,
+    },
+  ]);
+  expect(result.coverage).toMatchObject({
+    state: "partial",
+    issues: [
+      expect.objectContaining({
+        code: "invalid-heap-index",
+        scope: "metadata.#Strings",
+      }),
+    ],
+  });
+  expect(
+    result.coverage.issues.some(({ scope }) =>
+      scope.startsWith("metadata.MethodSpec:"),
+    ),
+  ).toBe(false);
+});
+
 describe("managed MethodDef heap admission", () => {
   it("keeps names from unpaged methods without reading their signatures or bodies", () => {
     const bytes = buildMultiMethodManagedPeFixture({

src/dotnet/ManagedMemberReferenceRows.ts

@@ -0,0 +1,33 @@
+import {
+  MEMBER_REF_PARENT_CODED_INDEX,
+  type ManagedMetadataLayout,
+} from "./ManagedMetadataLayout.js";
+import {
+  decodeMetadataCodedIndex,
+  metadataRowCursor,
+  metadataToken,
+} from "./ManagedMetadataHeaps.js";
+
+/** Scalar MemberRef facts; consumers own heap admission and parent diagnostics. */
+export const readMemberReferenceRowFacts = (
+  bytes: Buffer,
+  layout: ManagedMetadataLayout,
+  row: number,
+) => {
+  // Layout admission bounds the complete row independently of its heap values.
+  const cursor = metadataRowCursor(bytes, layout, 10, row);
+  const parentRaw = cursor.readIndex(layout.codedIndexSize("MemberRefParent"));
+  return {
+    token: metadataToken(10, row),
+    rowOffset: cursor.start,
+    parentRaw,
+    parent: decodeMetadataCodedIndex(
+      parentRaw,
+      MEMBER_REF_PARENT_CODED_INDEX.bits,
+      MEMBER_REF_PARENT_CODED_INDEX.tables,
+      layout.rowCounts,
+    ),
+    nameIndex: cursor.readIndex(layout.stringIndexSize),
+    signatureIndex: cursor.readIndex(layout.blobIndexSize),
+  };
+};

src/dotnet/ManagedMemberRows.ts

@@ -1,3 +1,4 @@
+import { readMemberReferenceRowFacts } from "./ManagedMemberReferenceRows.js";
 import { readMethodDefinitionRow } from "./ManagedMethodDefinitionRows.js";
 import { jsonStringByteLength } from "../domain/jsonStringByteLength.js";
 import { isManagedMemberReferenceInstruction } from "../domain/managed/managedMemberInstructionFacts.js";
@@ -234,34 +235,25 @@ export const parseMemberRefs = (
   const table = layout.table(10);
   for (let row = 1; row <= (table?.rowCount ?? 0); row += 1) {
     readManagedValue(() => {
-      const cursor = metadataRowCursor(bytes, layout, 10, row);
-      const parentRaw = cursor.readIndex(
-        layout.codedIndexSize("MemberRefParent"),
-      );
+      const { token, rowOffset, parentRaw, parent, nameIndex, signatureIndex } =
+        readMemberReferenceRowFacts(bytes, layout, row);
       const name = readMetadataString(
         bytes,
         layout,
-        cursor.readIndex(layout.stringIndexSize),
+        nameIndex,
         layout.strings.size,
       );
       const sig = readMetadataBlob(
         bytes,
         layout,
-        cursor.readIndex(layout.blobIndexSize),
+        signatureIndex,
         layout.blob?.size ?? 0,
       );
-      const token = metadataToken(10, row);
-      const parent = decodeMetadataCodedIndex(
-        parentRaw,
-        3,
-        [2, 1, 26, 6, 27],
-        layout.rowCounts,
-      );
       if (parent.kind !== "valid")
         issues.push({
           code: "invalid-row",
           scope: `metadata.MemberRef:${token}`,
-          offset: cursor.start,
+          offset: rowOffset,
           detail:
             parent.kind === "null"
               ? "MemberRef parent coded index 0x0 is null, but the Class column must reference a row"
@@ -278,7 +270,7 @@ export const parseMemberRefs = (
       );
       refs.push({
         token,
-        row_offset: cursor.start,
+        row_offset: rowOffset,
         parent_token: parentToken,
         parent_name: parentName,
         name,

src/dotnet/ManagedMetadataInventoryRows.ts

@@ -1,3 +1,4 @@
+import { readMemberReferenceRowFacts } from "./ManagedMemberReferenceRows.js";
 import { readTypeDefinitionRowFacts } from "./ManagedTypeDefinitionRows.js";
 import { managedDecodeBudget } from "./ManagedDecodeBudget.js";
 import { managedTypeReferences } from "./ManagedTypeReferences.js";
@@ -408,13 +409,7 @@ const attributeTypeName = (
   const { table, row } = constructor;
   if (table === 6)
     return declaringTypeForMethod(bytes, layout, row, memberLists, typeName);
-  const cursor = metadataRowCursor(bytes, layout, 10, row);
-  const parent = decodeMetadataCodedIndex(
-    cursor.readIndex(layout.codedIndexSize("MemberRefParent")),
-    3,
-    [2, 1, 26, 6, 27],
-    layout.rowCounts,
-  );
+  const { parent } = readMemberReferenceRowFacts(bytes, layout, row);
   if (parent.kind === "null") return null;
   if (parent.table === 2 || parent.table === 1)
     return typeName(parent.table, parent.row);

src/dotnet/ManagedMetadataLayout.ts

@@ -118,6 +118,9 @@ const CODED_INDEXES = {
   TypeOrMethodDef: { bits: 1, tables: [2, 6] },
 } as const;
 
+/** Shared MemberRef parent tag mapping, also used to select its column width. */
+export const MEMBER_REF_PARENT_CODED_INDEX = CODED_INDEXES.MemberRefParent;
+
 const SUPPORTED_TABLE_MASK = (1n << BigInt(METADATA_TABLE_NAMES.length)) - 1n;
 
 /** Check a range within `bytes`, which start at artifact file offset `base`. */

src/dotnet/ManagedMethodSpecs.ts

@@ -1,3 +1,4 @@
+import { readMemberReferenceRowFacts } from "./ManagedMemberReferenceRows.js";
 import { readMethodDefinitionRow } from "./ManagedMethodDefinitionRows.js";
 import { createHash } from "node:crypto";
 import type { ManagedParseIssue } from "../domain/managed/managedArtifact.js";
@@ -163,10 +164,11 @@ const methodSignatureBlob = (
   if (table === 6) {
     signatureIndex = readMethodDefinitionRow(bytes, layout, row).signatureIndex;
   } else {
-    const cursor = metadataRowCursor(bytes, layout, table, row);
-    cursor.readIndex(layout.codedIndexSize("MemberRefParent"));
-    cursor.readIndex(layout.stringIndexSize);
-    signatureIndex = cursor.readIndex(layout.blobIndexSize);
+    signatureIndex = readMemberReferenceRowFacts(
+      bytes,
+      layout,
+      row,
+    ).signatureIndex;
   }
   return readMetadataBlob(
     bytes,