[LLD][COFF] Separate EC and native exports for ARM64X (#123652)

Store exports in SymbolTable instead of Configuration.

Author: cjacek

lld/COFF/Config.h

@@ -162,8 +162,6 @@ struct Configuration {
   bool dll = false;
   StringRef implib;
   bool noimplib = false;
-  std::vector<Export> exports;
-  bool hadExplicitExports;
   std::set<std::string> delayLoads;
   std::map<std::string, int> dllOrder;
   Symbol *delayLoadHelper = nullptr;

lld/COFF/DLL.cpp

@@ -639,22 +639,22 @@ class ExportDirectoryChunk : public NonSectionChunk {
 
 class AddressTableChunk : public NonSectionChunk {
 public:
-  explicit AddressTableChunk(COFFLinkerContext &ctx, size_t baseOrdinal,
+  explicit AddressTableChunk(SymbolTable &symtab, size_t baseOrdinal,
                              size_t maxOrdinal)
       : baseOrdinal(baseOrdinal), size((maxOrdinal - baseOrdinal) + 1),
-        ctx(ctx) {}
+        symtab(symtab) {}
   size_t getSize() const override { return size * 4; }
 
   void writeTo(uint8_t *buf) const override {
     memset(buf, 0, getSize());
 
-    for (const Export &e : ctx.config.exports) {
+    for (const Export &e : symtab.exports) {
       assert(e.ordinal >= baseOrdinal && "Export symbol has invalid ordinal");
       // Subtract the OrdinalBase to get the index.
       uint8_t *p = buf + (e.ordinal - baseOrdinal) * 4;
       uint32_t bit = 0;
       // Pointer to thumb code must have the LSB set, so adjust it.
-      if (ctx.config.machine == ARMNT && !e.data)
+      if (symtab.machine == ARMNT && !e.data)
         bit = 1;
       if (e.forwardChunk) {
         write32le(p, e.forwardChunk->getRVA() | bit);
@@ -669,7 +669,7 @@ class AddressTableChunk : public NonSectionChunk {
 private:
   size_t baseOrdinal;
   size_t size;
-  const COFFLinkerContext &ctx;
+  const SymbolTable &symtab;
 };
 
 class NamePointersChunk : public NonSectionChunk {
@@ -690,13 +690,13 @@ class NamePointersChunk : public NonSectionChunk {
 
 class ExportOrdinalChunk : public NonSectionChunk {
 public:
-  explicit ExportOrdinalChunk(const COFFLinkerContext &ctx, size_t baseOrdinal,
+  explicit ExportOrdinalChunk(const SymbolTable &symtab, size_t baseOrdinal,
                               size_t tableSize)
-      : baseOrdinal(baseOrdinal), size(tableSize), ctx(ctx) {}
+      : baseOrdinal(baseOrdinal), size(tableSize), symtab(symtab) {}
   size_t getSize() const override { return size * 2; }
 
   void writeTo(uint8_t *buf) const override {
-    for (const Export &e : ctx.config.exports) {
+    for (const Export &e : symtab.exports) {
       if (e.noname)
         continue;
       assert(e.ordinal >= baseOrdinal && "Export symbol has invalid ordinal");
@@ -709,7 +709,7 @@ class ExportOrdinalChunk : public NonSectionChunk {
 private:
   size_t baseOrdinal;
   size_t size;
-  const COFFLinkerContext &ctx;
+  const SymbolTable &symtab;
 };
 
 } // anonymous namespace
@@ -920,33 +920,35 @@ Chunk *DelayLoadContents::newThunkChunk(DefinedImportData *s,
   }
 }
 
-void createEdataChunks(COFFLinkerContext &ctx, std::vector<Chunk *> &chunks) {
+void createEdataChunks(SymbolTable &symtab, std::vector<Chunk *> &chunks) {
   unsigned baseOrdinal = 1 << 16, maxOrdinal = 0;
-  for (Export &e : ctx.config.exports) {
+  for (Export &e : symtab.exports) {
     baseOrdinal = std::min(baseOrdinal, (unsigned)e.ordinal);
     maxOrdinal = std::max(maxOrdinal, (unsigned)e.ordinal);
   }
   // Ordinals must start at 1 as suggested in:
   // https://learn.microsoft.com/en-us/cpp/build/reference/export-exports-a-function?view=msvc-170
   assert(baseOrdinal >= 1);
 
-  auto *dllName = make<StringChunk>(sys::path::filename(ctx.config.outputFile));
-  auto *addressTab = make<AddressTableChunk>(ctx, baseOrdinal, maxOrdinal);
+  auto *dllName =
+      make<StringChunk>(sys::path::filename(symtab.ctx.config.outputFile));
+  auto *addressTab = make<AddressTableChunk>(symtab, baseOrdinal, maxOrdinal);
   std::vector<Chunk *> names;
-  for (Export &e : ctx.config.exports)
+  for (Export &e : symtab.exports)
     if (!e.noname)
       names.push_back(make<StringChunk>(e.exportName));
 
   std::vector<Chunk *> forwards;
-  for (Export &e : ctx.config.exports) {
+  for (Export &e : symtab.exports) {
     if (e.forwardTo.empty())
       continue;
     e.forwardChunk = make<StringChunk>(e.forwardTo);
     forwards.push_back(e.forwardChunk);
   }
 
   auto *nameTab = make<NamePointersChunk>(names);
-  auto *ordinalTab = make<ExportOrdinalChunk>(ctx, baseOrdinal, names.size());
+  auto *ordinalTab =
+      make<ExportOrdinalChunk>(symtab, baseOrdinal, names.size());
   auto *dir =
       make<ExportDirectoryChunk>(baseOrdinal, maxOrdinal, names.size(), dllName,
                                  addressTab, nameTab, ordinalTab);

lld/COFF/DLL.h

@@ -78,7 +78,7 @@ class DelayLoadContents {
 };
 
 // Create all chunks for the DLL export table.
-void createEdataChunks(COFFLinkerContext &ctx, std::vector<Chunk *> &chunks);
+void createEdataChunks(SymbolTable &symtab, std::vector<Chunk *> &chunks);
 
 } // namespace lld::coff
 

lld/COFF/Driver.cpp

@@ -458,7 +458,7 @@ void LinkerDriver::parseDirectives(InputFile *file) {
     // declarations, many object files may end up with having the
     // same /EXPORT options. In order to save cost of parsing them,
     // we dedup them first.
-    if (!directivesExports.insert(e).second)
+    if (!file->symtab.directivesExports.insert(e).second)
       continue;
 
     Export exp = parseExport(e);
@@ -469,7 +469,7 @@ void LinkerDriver::parseDirectives(InputFile *file) {
         exp.extName = saver().save("_" + exp.extName);
     }
     exp.source = ExportSource::Directives;
-    ctx.config.exports.push_back(exp);
+    file->symtab.exports.push_back(exp);
   }
 
   // Handle /include: in bulk.
@@ -956,7 +956,7 @@ std::string LinkerDriver::getImportName(bool asLib) {
 void LinkerDriver::createImportLibrary(bool asLib) {
   llvm::TimeTraceScope timeScope("Create import library");
   std::vector<COFFShortExport> exports;
-  for (Export &e1 : ctx.config.exports) {
+  for (Export &e1 : ctx.symtab.exports) {
     COFFShortExport e2;
     e2.Name = std::string(e1.name);
     e2.SymbolName = std::string(e1.symbolName);
@@ -1069,7 +1069,7 @@ void LinkerDriver::parseModuleDefs(StringRef path) {
     e2.isPrivate = e1.Private;
     e2.constant = e1.Constant;
     e2.source = ExportSource::ModuleDefinition;
-    ctx.config.exports.push_back(e2);
+    ctx.symtab.exports.push_back(e2);
   }
 }
 
@@ -1222,8 +1222,10 @@ static void findKeepUniqueSections(COFFLinkerContext &ctx) {
 
   // Exported symbols could be address-significant in other executables or DSOs,
   // so we conservatively mark them as address-significant.
-  for (Export &r : ctx.config.exports)
-    markAddrsig(r.sym);
+  ctx.forEachSymtab([](SymbolTable &symtab) {
+    for (Export &r : symtab.exports)
+      markAddrsig(r.sym);
+  });
 
   // Visit the address-significance table in each object file and mark each
   // referenced symbol as address-significant.
@@ -1376,13 +1378,13 @@ void LinkerDriver::maybeCreateECExportThunk(StringRef name, Symbol *&sym) {
 void LinkerDriver::createECExportThunks() {
   // Check if EXP+ symbols have corresponding $hp_target symbols and use them
   // to create export thunks when available.
-  for (Symbol *s : ctx.symtab.expSymbols) {
+  for (Symbol *s : ctx.symtabEC->expSymbols) {
     if (!s->isUsedInRegularObj)
       continue;
     assert(s->getName().starts_with("EXP+"));
     std::string targetName =
         (s->getName().substr(strlen("EXP+")) + "$hp_target").str();
-    Symbol *sym = ctx.symtab.find(targetName);
+    Symbol *sym = ctx.symtabEC->find(targetName);
     if (!sym)
       continue;
     Defined *targetSym;
@@ -1407,7 +1409,7 @@ void LinkerDriver::createECExportThunks() {
   if (ctx.symtabEC->entry)
     maybeCreateECExportThunk(ctx.symtabEC->entry->getName(),
                              ctx.symtabEC->entry);
-  for (Export &e : ctx.config.exports) {
+  for (Export &e : ctx.symtabEC->exports) {
     if (!e.data)
       maybeCreateECExportThunk(e.extName.empty() ? e.name : e.extName, e.sym);
   }
@@ -1430,7 +1432,7 @@ void LinkerDriver::maybeExportMinGWSymbols(const opt::InputArgList &args) {
     if (!ctx.config.dll)
       return;
 
-    if (!ctx.config.exports.empty())
+    if (!ctx.symtab.exports.empty())
       return;
     if (args.hasArg(OPT_exclude_all_symbols))
       return;
@@ -1466,7 +1468,7 @@ void LinkerDriver::maybeExportMinGWSymbols(const opt::InputArgList &args) {
       if (!(c->getOutputCharacteristics() & IMAGE_SCN_MEM_EXECUTE))
         e.data = true;
     s->isUsedInRegularObj = true;
-    ctx.config.exports.push_back(e);
+    ctx.symtab.exports.push_back(e);
   });
 }
 
@@ -2343,7 +2345,7 @@ void LinkerDriver::linkerMain(ArrayRef<const char *> argsArr) {
         if (!e.extName.empty() && !isDecorated(e.extName))
           e.extName = saver().save("_" + e.extName);
       }
-      config->exports.push_back(e);
+      mainSymtab.exports.push_back(e);
     }
   }
 
@@ -2355,7 +2357,7 @@ void LinkerDriver::linkerMain(ArrayRef<const char *> argsArr) {
 
   // Handle generation of import library from a def file.
   if (!args.hasArg(OPT_INPUT, OPT_wholearchive_file)) {
-    fixupExports();
+    ctx.forEachSymtab([](SymbolTable &symtab) { symtab.fixupExports(); });
     if (!config->noimplib)
       createImportLibrary(/*asLib=*/true);
     return;
@@ -2541,16 +2543,16 @@ void LinkerDriver::linkerMain(ArrayRef<const char *> argsArr) {
         // search for its mangled names.
         if (symtab.entry)
           symtab.mangleMaybe(symtab.entry);
-      });
 
-      // Windows specific -- Make sure we resolve all dllexported symbols.
-      for (Export &e : config->exports) {
-        if (!e.forwardTo.empty())
-          continue;
-        e.sym = ctx.symtab.addGCRoot(e.name, !e.data);
-        if (e.source != ExportSource::Directives)
-          e.symbolName = ctx.symtab.mangleMaybe(e.sym);
-      }
+        // Windows specific -- Make sure we resolve all dllexported symbols.
+        for (Export &e : symtab.exports) {
+          if (!e.forwardTo.empty())
+            continue;
+          e.sym = symtab.addGCRoot(e.name, !e.data);
+          if (e.source != ExportSource::Directives)
+            e.symbolName = symtab.mangleMaybe(e.sym);
+        }
+      });
 
       // Add weak aliases. Weak aliases is a mechanism to give remaining
       // undefined symbols final chance to be resolved successfully.
@@ -2651,7 +2653,9 @@ void LinkerDriver::linkerMain(ArrayRef<const char *> argsArr) {
   if (errorCount())
     return;
 
-  config->hadExplicitExports = !config->exports.empty();
+  ctx.forEachSymtab([](SymbolTable &symtab) {
+    symtab.hadExplicitExports = !symtab.exports.empty();
+  });
   if (config->mingw) {
     // In MinGW, all symbols are automatically exported if no symbols
     // are chosen to be exported.
@@ -2716,17 +2720,18 @@ void LinkerDriver::linkerMain(ArrayRef<const char *> argsArr) {
   // Windows specific -- when we are creating a .dll file, we also
   // need to create a .lib file. In MinGW mode, we only do that when the
   // -implib option is given explicitly, for compatibility with GNU ld.
-  if (!config->exports.empty() || config->dll) {
+  if (!ctx.symtab.exports.empty() || config->dll) {
     llvm::TimeTraceScope timeScope("Create .lib exports");
-    fixupExports();
+    ctx.forEachSymtab([](SymbolTable &symtab) { symtab.fixupExports(); });
     if (!config->noimplib && (!config->mingw || !config->implib.empty()))
       createImportLibrary(/*asLib=*/false);
-    assignExportOrdinals();
+    ctx.forEachSymtab(
+        [](SymbolTable &symtab) { symtab.assignExportOrdinals(); });
   }
 
   // Handle /output-def (MinGW specific).
   if (auto *arg = args.getLastArg(OPT_output_def))
-    writeDefFile(ctx, arg->getValue(), config->exports);
+    writeDefFile(ctx, arg->getValue(), ctx.symtab.exports);
 
   // Set extra alignment for .comm symbols
   for (auto pair : config->alignComm) {

lld/COFF/Driver.h

@@ -182,7 +182,6 @@ class LinkerDriver {
   std::list<std::function<void()>> taskQueue;
   std::vector<MemoryBufferRef> resources;
 
-  llvm::DenseSet<StringRef> directivesExports;
   llvm::DenseSet<StringRef> excludedSymbols;
 
   COFFLinkerContext &ctx;
@@ -249,8 +248,6 @@ class LinkerDriver {
 
   // Used for dllexported symbols.
   Export parseExport(StringRef arg);
-  void fixupExports();
-  void assignExportOrdinals();
 
   // Parses a string in the form of "key=value" and check
   // if value matches previous values for the key.