+
+ auto *N = F.getSubprogram();
+ if (!N)
+ return;
+
+ // Check that all !dbg attachments lead to back to N (or, at least, another
+ // subprogram that describes the same function).
+ //
+ // FIXME: Check this incrementally while visiting !dbg attachments.
+ // FIXME: Only check when N is the canonical subprogram for F.
+ SmallPtrSet<const MDNode *, 32> Seen;
+ for (auto &BB : F)
+ for (auto &I : BB) {
+ // Be careful about using DILocation here since we might be dealing with
+ // broken code (this is the Verifier after all).
+ DILocation *DL =
+ dyn_cast_or_null<DILocation>(I.getDebugLoc().getAsMDNode());
+ if (!DL)
+ continue;
+ if (!Seen.insert(DL).second)
+ continue;
+
+ DILocalScope *Scope = DL->getInlinedAtScope();
+ if (Scope && !Seen.insert(Scope).second)
+ continue;
+
+ DISubprogram *SP = Scope ? Scope->getSubprogram() : nullptr;
+
+ // Scope and SP could be the same MDNode and we don't want to skip
+ // validation in that case
+ if (SP && ((Scope != SP) && !Seen.insert(SP).second))
+ continue;
+
+ // FIXME: Once N is canonical, check "SP == &N".
+ Assert(SP->describes(&F),
+ "!dbg attachment points at wrong subprogram for function", N, &F,
+ &I, DL, Scope, SP);
+ }