[ORC][LibraryResolver] Fix ensureFilterBuilt assertion failure and concurrency issue. (llvm#166510)

- Fixed architecture compatibility check.
Previously, we used `sys::getDefaultTriple()`, which caused issues on
build bots
using cross-compilation. We now ensure that the target architecture
where the
shared library (.so) is run or loaded matches the architecture it was
built for.

- Fixed ensureFilterBuilt assertion failure.

- Replaced use of FilteredView with a safer alternative for concurrent
environments.
The old FilteredView approach iterated over shared state without
sufficient
synchronization, which could lead to invalid accesses when libraries
were being
added or removed concurrently.

Author: SahilPatidar

llvm/include/llvm/ExecutionEngine/Orc/TargetProcess/LibraryResolver.h

@@ -211,6 +211,21 @@ class LibraryManager {
     return FilteredView(Libraries.begin(), Libraries.end(), S, K);
   }
 
+  using LibraryFilterFn = std::function<bool(const LibraryInfo &)>;
+  void getLibraries(LibState S, PathType K,
+                    std::vector<std::shared_ptr<LibraryInfo>> &Outs,
+                    LibraryFilterFn Filter = nullptr) const {
+    std::shared_lock<std::shared_mutex> Lock(Mtx);
+    for (const auto &[_, Entry] : Libraries) {
+      const auto &Info = *Entry;
+      if (Info.getKind() != K || Info.getState() != S)
+        continue;
+      if (Filter && !Filter(Info))
+        continue;
+      Outs.push_back(Entry);
+    }
+  }
+
   void forEachLibrary(const LibraryVisitor &visitor) const {
     std::unique_lock<std::shared_mutex> Lock(Mtx);
     for (const auto &[_, entry] : Libraries) {
@@ -220,14 +235,14 @@ class LibraryManager {
   }
 
   bool isLoaded(StringRef Path) const {
-    std::unique_lock<std::shared_mutex> Lock(Mtx);
+    std::shared_lock<std::shared_mutex> Lock(Mtx);
     if (auto It = Libraries.find(Path.str()); It != Libraries.end())
       return It->second->getState() == LibState::Loaded;
     return false;
   }
 
   bool isQueried(StringRef Path) const {
-    std::unique_lock<std::shared_mutex> Lock(Mtx);
+    std::shared_lock<std::shared_mutex> Lock(Mtx);
     if (auto It = Libraries.find(Path.str()); It != Libraries.end())
       return It->second->getState() == LibState::Queried;
     return false;

llvm/lib/ExecutionEngine/Orc/TargetProcess/LibraryResolver.cpp

@@ -184,17 +184,17 @@ class SymbolSearchContext {
 public:
   SymbolSearchContext(SymbolQuery &Q) : Q(Q) {}
 
-  bool hasSearched(LibraryInfo *Lib) const { return Searched.count(Lib); }
+  bool hasSearched(const LibraryInfo *Lib) const { return Searched.count(Lib); }
 
-  void markSearched(LibraryInfo *Lib) { Searched.insert(Lib); }
+  void markSearched(const LibraryInfo *Lib) { Searched.insert(Lib); }
 
   inline bool allResolved() const { return Q.allResolved(); }
 
   SymbolQuery &query() { return Q; }
 
 private:
   SymbolQuery &Q;
-  DenseSet<LibraryInfo *> Searched;
+  DenseSet<const LibraryInfo *> Searched;
 };
 
 void LibraryResolver::resolveSymbolsInLibrary(
@@ -226,19 +226,18 @@ void LibraryResolver::resolveSymbolsInLibrary(
           return EnumerateResult::Continue;
         },
         Opts);
+  };
 
+  if (!Lib.hasFilter()) {
+    LLVM_DEBUG(dbgs() << "Building filter for library: " << Lib.getFullPath()
+                      << "\n";);
+    enumerateSymbolsIfNeeded();
     if (DiscoveredSymbols.empty()) {
       LLVM_DEBUG(dbgs() << "  No symbols and remove library : "
                         << Lib.getFullPath() << "\n";);
       LibMgr.removeLibrary(Lib.getFullPath());
       return;
     }
-  };
-
-  if (!Lib.hasFilter()) {
-    LLVM_DEBUG(dbgs() << "Building filter for library: " << Lib.getFullPath()
-                      << "\n";);
-    enumerateSymbolsIfNeeded();
     SmallVector<StringRef> SymbolVec;
     SymbolVec.reserve(DiscoveredSymbols.size());
     for (const auto &KV : DiscoveredSymbols)
@@ -288,24 +287,22 @@ void LibraryResolver::searchSymbolsInLibraries(
 
     SymbolSearchContext Ctx(Q);
     while (!Ctx.allResolved()) {
+      std::vector<std::shared_ptr<LibraryInfo>> Libs;
+      LibMgr.getLibraries(S, K, Libs, [&](const LibraryInfo &Lib) {
+        return !Ctx.hasSearched(&Lib);
+      });
 
-      for (auto &Lib : LibMgr.getView(S, K)) {
-        if (Ctx.hasSearched(Lib.get()))
-          continue;
+      if (Libs.empty() && !scanLibrariesIfNeeded(K, scanBatchSize))
+        break; // no more new libs to scan
 
+      for (auto &Lib : Libs) {
         // can use Async here?
         resolveSymbolsInLibrary(*Lib, Ctx.query(), Config.Options);
         Ctx.markSearched(Lib.get());
 
         if (Ctx.allResolved())
           return;
       }
-
-      if (Ctx.allResolved())
-        return;
-
-      if (!scanLibrariesIfNeeded(K, scanBatchSize))
-        break; // no more new libs to scan
     }
   };
 

llvm/lib/ExecutionEngine/Orc/TargetProcess/LibraryScanner.cpp

@@ -50,7 +50,7 @@ void handleError(Error Err, StringRef context = "") {
 }
 
 bool ObjectFileLoader::isArchitectureCompatible(const object::ObjectFile &Obj) {
-  Triple HostTriple(sys::getDefaultTargetTriple());
+  Triple HostTriple(sys::getProcessTriple());
   Triple ObjTriple = Obj.makeTriple();
 
   LLVM_DEBUG({