Change the implementation of --dynamic-list to use linker script parsing.

The feature is documented as
-----------------------------
The format of the dynamic list is the same as the version node
without scope and node name.  See *note VERSION:: for more
information.
--------------------------------

And indeed qt uses a dynamic list with an 'extern "C++"' in it. With
this patch we support that

The change to gc-sections-shared makes us match bfd. Just because we
kept bar doesn't mean it has to be in the dynamic symbol table.

The changes to invalid-dynamic-list.test and reproduce.s are because
of the new parser.

The changes to version-script.s are the only case where we change
behavior with regards to bfd, but I would like to see a mix of
--version-script and --dynamic-list used in the wild before
complicating the code.

llvm-svn: 289082
diff --git a/lld/ELF/Config.h b/lld/ELF/Config.h
index 9d7be7d..890e33a 100644
--- a/lld/ELF/Config.h
+++ b/lld/ELF/Config.h
@@ -87,7 +87,6 @@
   std::string RPath;
   std::vector<VersionDefinition> VersionDefinitions;
   std::vector<llvm::StringRef> AuxiliaryList;
-  std::vector<llvm::StringRef> DynamicList;
   std::vector<llvm::StringRef> SearchPaths;
   std::vector<llvm::StringRef> Undefined;
   std::vector<SymbolVersion> VersionScriptGlobals;
diff --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp
index 0bfc093..2095e73 100644
--- a/lld/ELF/Driver.cpp
+++ b/lld/ELF/Driver.cpp
@@ -627,14 +627,24 @@
 
   if (auto *Arg = Args.getLastArg(OPT_dynamic_list))
     if (Optional<MemoryBufferRef> Buffer = readFile(Arg->getValue()))
-      parseDynamicList(*Buffer);
+      readDynamicList(*Buffer);
 
   if (auto *Arg = Args.getLastArg(OPT_symbol_ordering_file))
     if (Optional<MemoryBufferRef> Buffer = readFile(Arg->getValue()))
       parseSymbolOrderingList(*Buffer);
 
   for (auto *Arg : Args.filtered(OPT_export_dynamic_symbol))
-    Config->DynamicList.push_back(Arg->getValue());
+    Config->VersionScriptGlobals.push_back(
+        {Arg->getValue(), /*IsExternCpp*/ false, /*HasWildcard*/ false});
+
+  // Dynamic lists are a simplified linker script that doesn't need the
+  // "global:" and implicitly ends with a "local:*". Set the variables needed to
+  // simulate that.
+  if (Args.hasArg(OPT_dynamic_list) || Args.hasArg(OPT_export_dynamic_symbol)) {
+    Config->ExportDynamic = true;
+    if (!Config->Shared)
+      Config->DefaultSymbolVersion = VER_NDX_LOCAL;
+  }
 
   if (auto *Arg = Args.getLastArg(OPT_version_script))
     if (Optional<MemoryBufferRef> Buffer = readFile(Arg->getValue()))
@@ -793,7 +803,6 @@
 
   Symtab.scanUndefinedFlags();
   Symtab.scanShlibUndefined();
-  Symtab.scanDynamicList();
   Symtab.scanVersionScript();
 
   Symtab.addCombinedLTOObject();
diff --git a/lld/ELF/Driver.h b/lld/ELF/Driver.h
index 74d465e..a3a3a84 100644
--- a/lld/ELF/Driver.h
+++ b/lld/ELF/Driver.h
@@ -69,7 +69,6 @@
 
 void printHelp(const char *Argv0);
 std::vector<uint8_t> parseHexstring(StringRef S);
-void parseDynamicList(MemoryBufferRef MB);
 
 std::string createResponseFile(const llvm::opt::InputArgList &Args);
 
diff --git a/lld/ELF/DriverUtils.cpp b/lld/ELF/DriverUtils.cpp
index d56dfba..6a270a6 100644
--- a/lld/ELF/DriverUtils.cpp
+++ b/lld/ELF/DriverUtils.cpp
@@ -90,32 +90,6 @@
   return Args;
 }
 
-// Parse the --dynamic-list argument.  A dynamic list is in the form
-//
-//  { symbol1; symbol2; [...]; symbolN };
-//
-// Multiple groups can be defined in the same file, and they are merged
-// into a single group.
-void elf::parseDynamicList(MemoryBufferRef MB) {
-  class Parser : public ScriptParserBase {
-  public:
-    Parser(MemoryBufferRef MB) : ScriptParserBase(MB) {}
-
-    void run() {
-      while (!atEOF()) {
-        expect("{");
-        while (!Error && !consume("}")) {
-          Config->DynamicList.push_back(unquote(next()));
-          expect(";");
-        }
-        expect(";");
-      }
-    }
-  };
-
-  Parser(MB).run();
-}
-
 void elf::printHelp(const char *Argv0) {
   ELFOptTable Table;
   Table.PrintHelp(outs(), Argv0, "lld", false);
diff --git a/lld/ELF/LinkerScript.cpp b/lld/ELF/LinkerScript.cpp
index f62cdce..50ce955 100644
--- a/lld/ELF/LinkerScript.cpp
+++ b/lld/ELF/LinkerScript.cpp
@@ -987,6 +987,7 @@
 
   void readLinkerScript();
   void readVersionScript();
+  void readDynamicList();
 
 private:
   void addFile(StringRef Path);
@@ -1040,6 +1041,13 @@
   std::vector<std::unique_ptr<MemoryBuffer>> OwningMBs;
 };
 
+void ScriptParser::readDynamicList() {
+  expect("{");
+  readAnonymousDeclaration();
+  if (!atEOF())
+    setError("EOF expected, but got " + next());
+}
+
 void ScriptParser::readVersionScript() {
   readVersionScriptCommand();
   if (!atEOF())
@@ -1932,7 +1940,7 @@
   StringRef Tok = next();
   bool IsCXX = Tok == "\"C++\"";
   if (!IsCXX && Tok != "\"C\"")
-    setError("Unknown Language");
+    setError("Unknown language");
   expect("{");
 
   std::vector<SymbolVersion> Ret;
@@ -1956,6 +1964,10 @@
   ScriptParser(MB).readVersionScript();
 }
 
+void elf::readDynamicList(MemoryBufferRef MB) {
+  ScriptParser(MB).readDynamicList();
+}
+
 template class elf::LinkerScript<ELF32LE>;
 template class elf::LinkerScript<ELF32BE>;
 template class elf::LinkerScript<ELF64LE>;
diff --git a/lld/ELF/LinkerScript.h b/lld/ELF/LinkerScript.h
index 3bcfc57..f6428e1 100644
--- a/lld/ELF/LinkerScript.h
+++ b/lld/ELF/LinkerScript.h
@@ -66,6 +66,8 @@
 // Parses a version script.
 void readVersionScript(MemoryBufferRef MB);
 
+void readDynamicList(MemoryBufferRef MB);
+
 // This enum is used to implement linker script SECTIONS command.
 // https://sourceware.org/binutils/docs/ld/SECTIONS.html#SECTIONS
 enum SectionsCommandKind {
diff --git a/lld/ELF/SymbolTable.cpp b/lld/ELF/SymbolTable.cpp
index 4fb611d..078fbb3 100644
--- a/lld/ELF/SymbolTable.cpp
+++ b/lld/ELF/SymbolTable.cpp
@@ -535,13 +535,6 @@
           Sym->symbol()->ExportDynamic = true;
 }
 
-// This function processes --export-dynamic-symbol and --dynamic-list.
-template <class ELFT> void SymbolTable<ELFT>::scanDynamicList() {
-  for (StringRef S : Config->DynamicList)
-    if (SymbolBody *B = find(S))
-      B->symbol()->ExportDynamic = true;
-}
-
 // Initialize DemangledSyms with a map from demangled symbols to symbol
 // objects. Used to handle "extern C++" directive in version scripts.
 //
diff --git a/lld/ELF/SymbolTable.h b/lld/ELF/SymbolTable.h
index 0e1b62f..cd9bef3 100644
--- a/lld/ELF/SymbolTable.h
+++ b/lld/ELF/SymbolTable.h
@@ -81,7 +81,6 @@
 
   void scanUndefinedFlags();
   void scanShlibUndefined();
-  void scanDynamicList();
   void scanVersionScript();
 
   SymbolBody *find(StringRef Name);