[PECOFF] Remove ResolvableSymbols to simplify.

We had such class there because of InputGraph abstraction.
Previously, no one except InputGraph itself has complete picture of
input file list. In order to create a set of all defined symbols,
we had to use some indirections there to workaround InputGraph.

It can now be rewritten as simple code. No change in functionality.

llvm-svn: 226319

lld/include/lld/ReaderWriter/PECOFFLinkingContext.h

@@ -30,28 +30,6 @@ static const uint8_t DEFAULT_DOS_STUB[128] = {'M', 'Z'};
 
 namespace lld {
 
-namespace pecoff {
-class ResolvableSymbols {
-public:
-  void add(File *file);
-
-  const std::set<std::string> &defined() {
-    readAllSymbols();
-    return _defined;
-  }
-
-private:
-  // Files are read lazily, so that it has no runtime overhead if
-  // no one accesses this class.
-  void readAllSymbols();
-
-  std::set<std::string> _defined;
-  std::set<File *> _seen;
-  std::set<File *> _queue;
-  std::mutex _mutex;
-};
-} // end namespace pecoff
-
 class PECOFFLinkingContext : public LinkingContext {
 public:
   PECOFFLinkingContext()
@@ -119,6 +97,9 @@ public:
     return _machineType == llvm::COFF::IMAGE_FILE_MACHINE_AMD64;
   }
 
+  // Returns a set of all defined symbols in input files.
+  const std::set<std::string> &definedSymbols();
+
   /// Page size of x86 processor. Some data needs to be aligned at page boundary
   /// when loaded into memory.
   uint64_t getPageSize() const {
@@ -345,10 +326,6 @@ public:
 
   std::recursive_mutex &getMutex() { return _mutex; }
 
-  pecoff::ResolvableSymbols *getResolvableSymsFile() {
-    return &_resolvableSyms;
-  }
-
 protected:
   /// Method to create a internal file for the entry symbol
   std::unique_ptr<File> createEntrySymbolFile() const override;
@@ -461,7 +438,8 @@ private:
   // only.
   std::string _moduleDefinitionFile;
 
-  pecoff::ResolvableSymbols _resolvableSyms;
+  std::set<std::string> _definedSyms;
+  std::set<Node *> _seen;
 };
 
 } // end namespace lld

lld/lib/Driver/WinLinkDriver.cpp

@@ -1414,7 +1414,6 @@ bool WinLinkDriver::parse(int argc, const char *argv[],
       File *f = file.get();
       ctx.getTaskGroup().spawn([f] { f->parse(); });
     }
-    ctx.getResolvableSymsFile()->add(file.get());
     ctx.getNodes().push_back(llvm::make_unique<FileNode>(std::move(file)));
   }
 
@@ -1431,7 +1430,6 @@ bool WinLinkDriver::parse(int argc, const char *argv[],
         File *f = file.get();
         ctx.getTaskGroup().spawn([f] { f->parse(); });
       }
-      ctx.getResolvableSymsFile()->add(file.get());
       ctx.addLibraryFile(llvm::make_unique<FileNode>(std::move(file)));
     }
   }

lld/lib/ReaderWriter/PECOFF/LinkerGeneratedSymbolFile.cpp

@@ -13,9 +13,9 @@ namespace lld {
 namespace pecoff {
 
 // Find decorated symbol, namely /sym@[0-9]+/ or /\?sym@@.+/.
-bool findDecoratedSymbol(PECOFFLinkingContext *ctx, ResolvableSymbols *syms,
+bool findDecoratedSymbol(PECOFFLinkingContext *ctx,
                          std::string sym, std::string &res) {
-  const std::set<std::string> &defined = syms->defined();
+  const std::set<std::string> &defined = ctx->definedSymbols();
   // Search for /sym@[0-9]+/
   {
     std::string s = sym + '@';

lld/lib/ReaderWriter/PECOFF/LinkerGeneratedSymbolFile.h

@@ -20,8 +20,7 @@ using llvm::COFF::WindowsSubsystem;
 namespace lld {
 namespace pecoff {
 
-class ResolvableSymbols;
-bool findDecoratedSymbol(PECOFFLinkingContext *ctx, ResolvableSymbols *syms,
+bool findDecoratedSymbol(PECOFFLinkingContext *ctx,
                          std::string sym, std::string &res);
 
 namespace impl {
@@ -206,9 +205,8 @@ private:
 // next visit.
 class ExportedSymbolRenameFile : public impl::VirtualArchiveLibraryFile {
 public:
-  ExportedSymbolRenameFile(const PECOFFLinkingContext &ctx,
-                           ResolvableSymbols *syms)
-      : VirtualArchiveLibraryFile("<export>"), _syms(syms),
+  ExportedSymbolRenameFile(const PECOFFLinkingContext &ctx)
+      : VirtualArchiveLibraryFile("<export>"),
         _ctx(const_cast<PECOFFLinkingContext *>(&ctx)) {
     for (PECOFFLinkingContext::ExportDesc &desc : _ctx->getDllExports())
       _exportedSyms.insert(desc.name);
@@ -219,7 +217,7 @@ public:
     if (_exportedSyms.count(sym) == 0)
       return nullptr;
     std::string replace;
-    if (!findDecoratedSymbol(_ctx, _syms, sym.str(), replace))
+    if (!findDecoratedSymbol(_ctx, sym.str(), replace))
       return nullptr;
 
     for (ExportDesc &exp : _ctx->getDllExports())
@@ -232,7 +230,6 @@ public:
 
 private:
   std::set<std::string> _exportedSyms;
-  ResolvableSymbols *_syms;
   mutable llvm::BumpPtrAllocator _alloc;
   mutable PECOFFLinkingContext *_ctx;
 };
@@ -244,10 +241,9 @@ private:
 // http://msdn.microsoft.com/en-us/library/f9t8842e.aspx
 class EntryPointFile : public SimpleFile {
 public:
-  EntryPointFile(const PECOFFLinkingContext &ctx,
-                 ResolvableSymbols *syms)
+  EntryPointFile(const PECOFFLinkingContext &ctx)
       : SimpleFile("<entry>"), _ctx(const_cast<PECOFFLinkingContext *>(&ctx)),
-        _syms(syms), _firstTime(true) {}
+        _firstTime(true) {}
 
   const atom_collection<UndefinedAtom> &undefined() const override {
     return const_cast<EntryPointFile *>(this)->getUndefinedAtoms();
@@ -277,7 +273,7 @@ private:
     StringRef opt = _ctx->getEntrySymbolName();
     if (!opt.empty()) {
       std::string mangled;
-      if (findDecoratedSymbol(_ctx, _syms, opt, mangled))
+      if (findDecoratedSymbol(_ctx, opt, mangled))
         return mangled;
       return _ctx->decorateSymbol(opt);
     }
@@ -299,10 +295,10 @@ private:
     // Returns true if a given name exists in an input object file.
     auto defined = [&](StringRef name) -> bool {
       StringRef sym = _ctx->decorateSymbol(name);
-      if (_syms->defined().count(sym))
+      if (_ctx->definedSymbols().count(sym))
         return true;
       std::string ignore;
-      return findDecoratedSymbol(_ctx, _syms, sym, ignore);
+      return findDecoratedSymbol(_ctx, sym, ignore);
     };
 
     switch (_ctx->getSubsystem()) {
@@ -333,7 +329,6 @@ private:
   PECOFFLinkingContext *_ctx;
   atom_collection_vector<UndefinedAtom> _undefinedAtoms;
   std::mutex _mutex;
-  ResolvableSymbols *_syms;
   llvm::BumpPtrAllocator _alloc;
   bool _firstTime;
 };

lld/lib/ReaderWriter/PECOFF/PECOFFLinkingContext.cpp

@@ -78,6 +78,29 @@ bool PECOFFLinkingContext::validateImpl(raw_ostream &diagnostics) {
   return true;
 }
 
+const std::set<std::string> &PECOFFLinkingContext::definedSymbols() {
+  std::lock_guard<std::recursive_mutex> lock(_mutex);
+  for (std::unique_ptr<Node> &node : getNodes()) {
+    if (_seen.count(node.get()) > 0)
+      continue;
+    FileNode *fnode = dyn_cast<FileNode>(node.get());
+    if (!fnode)
+      continue;
+    File *file = fnode->getFile();
+    if (file->parse())
+      continue;
+    if (auto *archive = dyn_cast<ArchiveLibraryFile>(file)) {
+      for (const std::string &sym : archive->getDefinedSymbols())
+        _definedSyms.insert(sym);
+      continue;
+    }
+    for (const DefinedAtom *atom : file->defined())
+      if (!atom->name().empty())
+        _definedSyms.insert(atom->name());
+  }
+  return _definedSyms;
+}
+
 std::unique_ptr<File> PECOFFLinkingContext::createEntrySymbolFile() const {
   return LinkingContext::createEntrySymbolFile("<command line option /entry>");
 }
@@ -112,12 +135,11 @@ void PECOFFLinkingContext::addLibraryFile(std::unique_ptr<FileNode> file) {
 
 bool PECOFFLinkingContext::createImplicitFiles(
     std::vector<std::unique_ptr<File>> &) {
-  pecoff::ResolvableSymbols* syms = getResolvableSymsFile();
   std::vector<std::unique_ptr<Node>> &members = getNodes();
 
   // Create a file for the entry point function.
   std::unique_ptr<FileNode> entry(new FileNode(
-      llvm::make_unique<pecoff::EntryPointFile>(*this, syms)));
+      llvm::make_unique<pecoff::EntryPointFile>(*this)));
   members.insert(members.begin() + getGroupStartPos(members), std::move(entry));
 
   // Create a file for __ImageBase.
@@ -132,7 +154,7 @@ bool PECOFFLinkingContext::createImplicitFiles(
 
   // Create a file for dllexported symbols.
   std::unique_ptr<FileNode> exportNode(new FileNode(
-      llvm::make_unique<pecoff::ExportedSymbolRenameFile>(*this, syms)));
+      llvm::make_unique<pecoff::ExportedSymbolRenameFile>(*this)));
   addLibraryFile(std::move(exportNode));
 
   return true;
@@ -335,29 +357,4 @@ void PECOFFLinkingContext::addPasses(PassManager &pm) {
   pm.add(std::unique_ptr<Pass>(new pecoff::InferSubsystemPass(*this)));
 }
 
-void pecoff::ResolvableSymbols::add(File *file) {
-  std::lock_guard<std::mutex> lock(_mutex);
-  if (_seen.count(file) > 0)
-    return;
-  _seen.insert(file);
-  _queue.insert(file);
-}
-
-void pecoff::ResolvableSymbols::readAllSymbols() {
-  std::lock_guard<std::mutex> lock(_mutex);
-  for (File *file : _queue) {
-    if (file->parse())
-      return;
-    if (auto *archive = dyn_cast<ArchiveLibraryFile>(file)) {
-      for (const std::string &sym : archive->getDefinedSymbols())
-	_defined.insert(sym);
-      continue;
-    }
-    for (const DefinedAtom *atom : file->defined())
-      if (!atom->name().empty())
-	_defined.insert(atom->name());
-  }
-  _queue.clear();
-}
-
 } // end namespace lld