pdb: Fix isPureVirtualMethod to recognize PureIntroducingVirtual

Port of getsentry/pdb#135. Add FieldAttributes helper functions
(isStaticMethod, isVirtualMethod, isPureVirtualMethod,
isIntroVirtualMethod) matching the Rust FieldAttributes methods.
isPureVirtualMethod correctly returns true for both PureVirtual and
PureIntroducingVirtual method kinds.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: kjk

pdb/src/index.ts

@@ -95,6 +95,10 @@ export {
   CallingConvention,
   PointerKind,
   PointerMode,
+  isStaticMethod,
+  isVirtualMethod,
+  isPureVirtualMethod,
+  isIntroVirtualMethod,
 } from "./tpi/types.js";
 export type { RawItem, TypeInformation } from "./tpi/parser.js";
 export { ItemFinder } from "./tpi/parser.js";

pdb/src/tpi/parser.ts

@@ -13,10 +13,10 @@ import type {
 import {
   parseTypeProperties,
   parseFieldAttributes,
+  isIntroVirtualMethod,
   parsePointerAttributes,
   parseFunctionAttributes,
   PointerMode,
-  MethodKind,
 } from "./types.js";
 
 /** Header of the TPI/IPI stream. */
@@ -361,8 +361,7 @@ function parseTypeRecord(buf: ParseBuffer, kind: number): TypeData {
         const methodType: TypeIndex = buf.readU32();
         let vtableOffset: number | null = null;
         if (
-          attributes.mprop === MethodKind.IntroducingVirtual ||
-          attributes.mprop === MethodKind.PureIntroducingVirtual
+          isIntroVirtualMethod(attributes)
         ) {
           vtableOffset = buf.readU32();
         }
@@ -465,10 +464,7 @@ function parseFieldRecord(buf: ParseBuffer, kind: number): TypeData | null {
       const attributes = parseFieldAttributes(attrRaw);
       const methodType: TypeIndex = buf.readU32();
       let vtableOffset: number | null = null;
-      if (
-        attributes.mprop === MethodKind.IntroducingVirtual ||
-        attributes.mprop === MethodKind.PureIntroducingVirtual
-      ) {
+      if (isIntroVirtualMethod(attributes)) {
         vtableOffset = buf.readU32();
       }
       const name = readTypeName(buf, kind);

pdb/src/tpi/types.ts

@@ -76,6 +76,28 @@ export function parseFieldAttributes(raw: number): FieldAttributes {
   };
 }
 
+/** Returns true if the method is static. */
+export function isStaticMethod(attr: FieldAttributes): boolean {
+  return attr.mprop === MethodKind.Static;
+}
+
+/** Returns true if the method is virtual. */
+export function isVirtualMethod(attr: FieldAttributes): boolean {
+  return attr.mprop === MethodKind.Virtual;
+}
+
+/** Returns true if the method is pure virtual (includes pure introducing virtual). */
+export function isPureVirtualMethod(attr: FieldAttributes): boolean {
+  return attr.mprop === MethodKind.PureVirtual ||
+    attr.mprop === MethodKind.PureIntroducingVirtual;
+}
+
+/** Returns true if the method is an introducing virtual (includes pure introducing virtual). */
+export function isIntroVirtualMethod(attr: FieldAttributes): boolean {
+  return attr.mprop === MethodKind.IntroducingVirtual ||
+    attr.mprop === MethodKind.PureIntroducingVirtual;
+}
+
 /** The kind of a PointerType. */
 export enum PointerKind {
   Near16 = 0x00,