[LLD] Remove global state in lldCommon

Move all variables at file-scope or function-static-scope into a hosting structure (lld::CommonLinkerContext) that lives at lldMain()-scope. Drivers will inherit from this structure and add their own global state, in the same way as for the existing COFFLinkerContext.

See discussion in https://lists.llvm.org/pipermail/llvm-dev/2021-June/151184.html

Differential Revision: https://reviews.llvm.org/D108850

Author: aganea

lld/COFF/COFFLinkerContext.h

@@ -15,12 +15,13 @@
 #include "InputFiles.h"
 #include "SymbolTable.h"
 #include "Writer.h"
+#include "lld/Common/CommonLinkerContext.h"
 #include "lld/Common/Timer.h"
 
 namespace lld {
 namespace coff {
 
-class COFFLinkerContext {
+class COFFLinkerContext : public CommonLinkerContext {
 public:
   COFFLinkerContext();
   COFFLinkerContext(const COFFLinkerContext &) = delete;

lld/COFF/Chunks.cpp

@@ -12,7 +12,6 @@
 #include "SymbolTable.h"
 #include "Symbols.h"
 #include "Writer.h"
-#include "lld/Common/ErrorHandler.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/BinaryFormat/COFF.h"
 #include "llvm/Object/COFF.h"
@@ -430,7 +429,7 @@ void SectionChunk::sortRelocations() {
     return;
   warn("some relocations in " + file->getName() + " are not sorted");
   MutableArrayRef<coff_relocation> newRelocs(
-      bAlloc.Allocate<coff_relocation>(relocsSize), relocsSize);
+      bAlloc().Allocate<coff_relocation>(relocsSize), relocsSize);
   memcpy(newRelocs.data(), relocsData, relocsSize * sizeof(coff_relocation));
   llvm::sort(newRelocs, cmpByVa);
   setRelocs(newRelocs);

lld/COFF/DLL.cpp

@@ -659,14 +659,14 @@ void DelayLoadContents::create(COFFLinkerContext &ctx, Defined *h) {
         // Add a syntentic symbol for this load thunk, using the "__imp_load"
         // prefix, in case this thunk needs to be added to the list of valid
         // call targets for Control Flow Guard.
-        StringRef symName = saver.save("__imp_load_" + extName);
+        StringRef symName = saver().save("__imp_load_" + extName);
         s->loadThunkSym =
             cast<DefinedSynthetic>(ctx.symtab.addSynthetic(symName, t));
       }
     }
     thunks.push_back(tm);
     StringRef tmName =
-        saver.save("__tailMerge_" + syms[0]->getDLLName().lower());
+        saver().save("__tailMerge_" + syms[0]->getDLLName().lower());
     ctx.symtab.addSynthetic(tmName, tm);
     // Terminate with null values.
     addresses.push_back(make<NullChunk>(8));

lld/COFF/Driver.cpp

@@ -19,9 +19,7 @@
 #include "Writer.h"
 #include "lld/Common/Args.h"
 #include "lld/Common/Driver.h"
-#include "lld/Common/ErrorHandler.h"
 #include "lld/Common/Filesystem.h"
-#include "lld/Common/Memory.h"
 #include "lld/Common/Timer.h"
 #include "lld/Common/Version.h"
 #include "llvm/ADT/Optional.h"
@@ -63,36 +61,23 @@ namespace coff {
 std::unique_ptr<Configuration> config;
 std::unique_ptr<LinkerDriver> driver;
 
-bool link(ArrayRef<const char *> args, bool canExitEarly, raw_ostream &stdoutOS,
-          raw_ostream &stderrOS) {
-  lld::stdoutOS = &stdoutOS;
-  lld::stderrOS = &stderrOS;
+bool link(ArrayRef<const char *> args, raw_ostream &stdoutOS,
+          raw_ostream &stderrOS, bool exitEarly, bool disableOutput) {
+  // This driver-specific context will be freed later by lldMain().
+  // It is created on the heap to avoid destructors if 'exitEarly' is set.
+  auto *ctx = new COFFLinkerContext;
 
-  errorHandler().cleanupCallback = []() {
-    freeArena();
-  };
-
-  errorHandler().logName = args::getFilenameWithoutExe(args[0]);
-  errorHandler().errorLimitExceededMsg =
-      "too many errors emitted, stopping now"
-      " (use /errorlimit:0 to see all errors)";
-  errorHandler().exitEarly = canExitEarly;
-  stderrOS.enable_colors(stderrOS.has_colors());
+  ctx->e.initialize(stdoutOS, stderrOS, exitEarly, disableOutput);
+  ctx->e.logName = args::getFilenameWithoutExe(args[0]);
+  ctx->e.errorLimitExceededMsg = "too many errors emitted, stopping now"
+                                 " (use /errorlimit:0 to see all errors)";
 
-  COFFLinkerContext ctx;
   config = std::make_unique<Configuration>();
-  driver = std::make_unique<LinkerDriver>(ctx);
+  driver = std::make_unique<LinkerDriver>(*ctx);
 
   driver->linkerMain(args);
 
-  // Call exit() if we can to avoid calling destructors.
-  if (canExitEarly)
-    exitLld(errorCount() ? 1 : 0);
-
-  bool ret = errorCount() == 0;
-  if (!canExitEarly)
-    errorHandler().reset();
-  return ret;
+  return errorCount() == 0;
 }
 
 // Parse options of the form "old;new".
@@ -162,7 +147,7 @@ static std::future<MBErrPair> createFutureForFile(std::string path) {
 static StringRef mangle(StringRef sym) {
   assert(config->machine != IMAGE_FILE_MACHINE_UNKNOWN);
   if (config->machine == I386)
-    return saver.save("_" + sym);
+    return saver().save("_" + sym);
   return sym;
 }
 
@@ -358,9 +343,9 @@ void LinkerDriver::parseDirectives(InputFile *file) {
     Export exp = parseExport(e);
     if (config->machine == I386 && config->mingw) {
       if (!isDecorated(exp.name))
-        exp.name = saver.save("_" + exp.name);
+        exp.name = saver().save("_" + exp.name);
       if (!exp.extName.empty() && !isDecorated(exp.extName))
-        exp.extName = saver.save("_" + exp.extName);
+        exp.extName = saver().save("_" + exp.extName);
     }
     exp.directives = true;
     config->exports.push_back(exp);
@@ -442,11 +427,11 @@ StringRef LinkerDriver::doFindFile(StringRef filename) {
     SmallString<128> path = dir;
     sys::path::append(path, filename);
     if (sys::fs::exists(path.str()))
-      return saver.save(path.str());
+      return saver().save(path.str());
     if (!hasExt) {
       path.append(".obj");
       if (sys::fs::exists(path.str()))
-        return saver.save(path.str());
+        return saver().save(path.str());
     }
   }
   return filename;
@@ -483,7 +468,7 @@ StringRef LinkerDriver::doFindLibMinGW(StringRef filename) {
 
   SmallString<128> s = filename;
   sys::path::replace_extension(s, ".a");
-  StringRef libName = saver.save("lib" + s.str());
+  StringRef libName = saver().save("lib" + s.str());
   return doFindFile(libName);
 }
 
@@ -492,7 +477,7 @@ StringRef LinkerDriver::doFindLib(StringRef filename) {
   // Add ".lib" to Filename if that has no file extension.
   bool hasExt = filename.contains('.');
   if (!hasExt)
-    filename = saver.save(filename + ".lib");
+    filename = saver().save(filename + ".lib");
   StringRef ret = doFindFile(filename);
   // For MinGW, if the find above didn't turn up anything, try
   // looking for a MinGW formatted library name.
@@ -525,7 +510,7 @@ void LinkerDriver::addLibSearchPaths() {
   Optional<std::string> envOpt = Process::GetEnv("LIB");
   if (!envOpt.hasValue())
     return;
-  StringRef env = saver.save(*envOpt);
+  StringRef env = saver().save(*envOpt);
   while (!env.empty()) {
     StringRef path;
     std::tie(path, env) = env.split(';');
@@ -872,8 +857,8 @@ static void parseModuleDefs(StringRef path) {
   driver->takeBuffer(std::move(mb));
 
   if (config->outputFile.empty())
-    config->outputFile = std::string(saver.save(m.OutputFile));
-  config->importName = std::string(saver.save(m.ImportName));
+    config->outputFile = std::string(saver().save(m.OutputFile));
+  config->importName = std::string(saver().save(m.ImportName));
   if (m.ImageBase)
     config->imageBase = m.ImageBase;
   if (m.StackReserve)
@@ -901,13 +886,13 @@ static void parseModuleDefs(StringRef path) {
     // DLL instead. This is supported by both MS and GNU linkers.
     if (!e1.ExtName.empty() && e1.ExtName != e1.Name &&
         StringRef(e1.Name).contains('.')) {
-      e2.name = saver.save(e1.ExtName);
-      e2.forwardTo = saver.save(e1.Name);
+      e2.name = saver().save(e1.ExtName);
+      e2.forwardTo = saver().save(e1.Name);
       config->exports.push_back(e2);
       continue;
     }
-    e2.name = saver.save(e1.Name);
-    e2.extName = saver.save(e1.ExtName);
+    e2.name = saver().save(e1.Name);
+    e2.extName = saver().save(e1.ExtName);
     e2.ordinal = e1.Ordinal;
     e2.noname = e1.Noname;
     e2.data = e1.Data;
@@ -1904,9 +1889,9 @@ void LinkerDriver::linkerMain(ArrayRef<const char *> argsArr) {
     Export e = parseExport(arg->getValue());
     if (config->machine == I386) {
       if (!isDecorated(e.name))
-        e.name = saver.save("_" + e.name);
+        e.name = saver().save("_" + e.name);
       if (!e.extName.empty() && !isDecorated(e.extName))
-        e.extName = saver.save("_" + e.extName);
+        e.extName = saver().save("_" + e.extName);
     }
     config->exports.push_back(e);
   }

lld/COFF/DriverUtils.cpp

@@ -48,17 +48,17 @@ const uint16_t RT_MANIFEST = 24;
 
 class Executor {
 public:
-  explicit Executor(StringRef s) : prog(saver.save(s)) {}
-  void add(StringRef s) { args.push_back(saver.save(s)); }
-  void add(std::string &s) { args.push_back(saver.save(s)); }
-  void add(Twine s) { args.push_back(saver.save(s)); }
-  void add(const char *s) { args.push_back(saver.save(s)); }
+  explicit Executor(StringRef s) : prog(saver().save(s)) {}
+  void add(StringRef s) { args.push_back(saver().save(s)); }
+  void add(std::string &s) { args.push_back(saver().save(s)); }
+  void add(Twine s) { args.push_back(saver().save(s)); }
+  void add(const char *s) { args.push_back(saver().save(s)); }
 
   void run() {
     ErrorOr<std::string> exeOrErr = sys::findProgramByName(prog);
     if (auto ec = exeOrErr.getError())
       fatal("unable to find " + prog + " in PATH: " + ec.message());
-    StringRef exe = saver.save(*exeOrErr);
+    StringRef exe = saver().save(*exeOrErr);
     args.insert(args.begin(), exe);
 
     if (sys::ExecuteAndWait(args[0], args) != 0)
@@ -636,14 +636,14 @@ static StringRef killAt(StringRef sym, bool prefix) {
   sym = sym.substr(0, sym.find('@', 1));
   if (!sym.startswith("@")) {
     if (prefix && !sym.startswith("_"))
-      return saver.save("_" + sym);
+      return saver().save("_" + sym);
     return sym;
   }
   // For fastcall, remove the leading @ and replace it with an
   // underscore, if prefixes are used.
   sym = sym.substr(1);
   if (prefix)
-    sym = saver.save("_" + sym);
+    sym = saver().save("_" + sym);
   return sym;
 }
 
@@ -854,7 +854,7 @@ opt::InputArgList ArgParser::parse(ArrayRef<const char *> argv) {
                                               argv.data() + argv.size());
   if (!args.hasArg(OPT_lldignoreenv))
     addLINK(expandedArgv);
-  cl::ExpandResponseFiles(saver, getQuotingStyle(args), expandedArgv);
+  cl::ExpandResponseFiles(saver(), getQuotingStyle(args), expandedArgv);
   args = optTable.ParseArgs(makeArrayRef(expandedArgv).drop_front(),
                             missingIndex, missingCount);
 
@@ -901,7 +901,7 @@ ParsedDirectives ArgParser::parseDirectives(StringRef s) {
   // Handle /EXPORT and /INCLUDE in a fast path. These directives can appear for
   // potentially every symbol in the object, so they must be handled quickly.
   SmallVector<StringRef, 16> tokens;
-  cl::TokenizeWindowsCommandLineNoCopy(s, saver, tokens);
+  cl::TokenizeWindowsCommandLineNoCopy(s, saver(), tokens);
   for (StringRef tok : tokens) {
     if (tok.startswith_insensitive("/export:") ||
         tok.startswith_insensitive("-export:"))
@@ -914,7 +914,7 @@ ParsedDirectives ArgParser::parseDirectives(StringRef s) {
       // already copied quoted arguments for us, so those do not need to be
       // copied again.
       bool HasNul = tok.end() != s.end() && tok.data()[tok.size()] == '\0';
-      rest.push_back(HasNul ? tok.data() : saver.save(tok).data());
+      rest.push_back(HasNul ? tok.data() : saver().save(tok).data());
     }
   }
 
@@ -948,7 +948,7 @@ void ArgParser::addLINK(SmallVector<const char *, 256> &argv) {
 
 std::vector<const char *> ArgParser::tokenize(StringRef s) {
   SmallVector<const char *, 16> tokens;
-  cl::TokenizeWindowsCommandLine(s, saver, tokens);
+  cl::TokenizeWindowsCommandLine(s, saver(), tokens);
   return std::vector<const char *>(tokens.begin(), tokens.end());
 }
 

lld/COFF/InputFiles.cpp

@@ -15,8 +15,6 @@
 #include "SymbolTable.h"
 #include "Symbols.h"
 #include "lld/Common/DWARF.h"
-#include "lld/Common/ErrorHandler.h"
-#include "lld/Common/Memory.h"
 #include "llvm-c/lto.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Triple.h"
@@ -905,7 +903,7 @@ ObjFile::getVariableLocation(StringRef var) {
   Optional<std::pair<std::string, unsigned>> ret = dwarf->getVariableLoc(var);
   if (!ret)
     return None;
-  return std::make_pair(saver.save(ret->first), ret->second);
+  return std::make_pair(saver().save(ret->first), ret->second);
 }
 
 // Used only for DWARF debug info, which is not common (except in MinGW
@@ -940,8 +938,8 @@ void ImportFile::parse() {
     fatal("broken import library");
 
   // Read names and create an __imp_ symbol.
-  StringRef name = saver.save(StringRef(buf + sizeof(*hdr)));
-  StringRef impName = saver.save("__imp_" + name);
+  StringRef name = saver().save(StringRef(buf + sizeof(*hdr)));
+  StringRef impName = saver().save("__imp_" + name);
   const char *nameStart = buf + sizeof(coff_import_header) + name.size() + 1;
   dllName = std::string(StringRef(nameStart));
   StringRef extName;
@@ -995,11 +993,12 @@ BitcodeFile::BitcodeFile(COFFLinkerContext &ctx, MemoryBufferRef mb,
   // into consideration at LTO time (which very likely causes undefined
   // symbols later in the link stage). So we append file offset to make
   // filename unique.
-  MemoryBufferRef mbref(
-      mb.getBuffer(),
-      saver.save(archiveName.empty() ? path
-                                     : archiveName + sys::path::filename(path) +
-                                           utostr(offsetInArchive)));
+  MemoryBufferRef mbref(mb.getBuffer(),
+                        saver().save(archiveName.empty()
+                                         ? path
+                                         : archiveName +
+                                               sys::path::filename(path) +
+                                               utostr(offsetInArchive)));
 
   obj = check(lto::InputFile::create(mbref));
 }
@@ -1035,6 +1034,7 @@ FakeSectionChunk ltoDataSectionChunk(&ltoDataSection.section);
 } // namespace
 
 void BitcodeFile::parse() {
+  llvm::StringSaver &saver = lld::saver();
   std::vector<std::pair<Symbol *, bool>> comdat(obj->getComdatTable().size());
   for (size_t i = 0; i != obj->getComdatTable().size(); ++i)
     // FIXME: Check nodeduplicate
@@ -1156,11 +1156,11 @@ void DLLFile::parse() {
     s->nameType = ImportNameType::IMPORT_NAME;
 
     if (coffObj->getMachine() == I386) {
-      s->symbolName = symbolName = saver.save("_" + symbolName);
+      s->symbolName = symbolName = saver().save("_" + symbolName);
       s->nameType = ImportNameType::IMPORT_NAME_NOPREFIX;
     }
 
-    StringRef impName = saver.save("__imp_" + symbolName);
+    StringRef impName = saver().save("__imp_" + symbolName);
     ctx.symtab.addLazyDLLSymbol(this, s, impName);
     if (code)
       ctx.symtab.addLazyDLLSymbol(this, s, symbolName);
@@ -1179,7 +1179,7 @@ void DLLFile::makeImport(DLLFile::Symbol *s) {
 
   size_t impSize = s->dllName.size() + s->symbolName.size() + 2; // +2 for NULs
   size_t size = sizeof(coff_import_header) + impSize;
-  char *buf = bAlloc.Allocate<char>(size);
+  char *buf = bAlloc().Allocate<char>(size);
   memset(buf, 0, size);
   char *p = buf;
   auto *imp = reinterpret_cast<coff_import_header *>(p);

lld/COFF/LTO.cpp

@@ -11,7 +11,7 @@
 #include "InputFiles.h"
 #include "Symbols.h"
 #include "lld/Common/Args.h"
-#include "lld/Common/ErrorHandler.h"
+#include "lld/Common/CommonLinkerContext.h"
 #include "lld/Common/Strings.h"
 #include "lld/Common/TargetOptionsCommandFlags.h"
 #include "llvm/ADT/STLExtras.h"
@@ -209,8 +209,8 @@ std::vector<InputFile *> BitcodeCompiler::compile(COFFLinkerContext &ctx) {
     // - foo.exe.lto.1.obj
     // - ...
     StringRef ltoObjName =
-        saver.save(Twine(config->outputFile) + ".lto" +
-                   (i == 0 ? Twine("") : Twine('.') + Twine(i)) + ".obj");
+        saver().save(Twine(config->outputFile) + ".lto" +
+                     (i == 0 ? Twine("") : Twine('.') + Twine(i)) + ".obj");
 
     // Get the native object contents either from the cache or from memory.  Do
     // not use the cached MemoryBuffer directly, or the PDB will not be