vendor/lld/lld-trunk-r321017

1 files changed, 146 insertions, 0 deletions

diff --git a/COFF/MinGW.cpp b/COFF/MinGW.cpp
new file mode 100644
index 000000000000..b7a47165640d
--- /dev/null
+++ b/COFF/MinGW.cpp
@@ -0,0 +1,146 @@
+//===- MinGW.cpp ----------------------------------------------------------===//
+//
+//                             The LLVM Linker
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "MinGW.h"
+#include "SymbolTable.h"
+#include "lld/Common/ErrorHandler.h"
+#include "llvm/Object/COFF.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace lld;
+using namespace lld::coff;
+using namespace llvm;
+using namespace llvm::COFF;
+
+AutoExporter::AutoExporter() {
+  if (Config->Machine == I386) {
+    ExcludeSymbols = {
+        "__NULL_IMPORT_DESCRIPTOR",
+        "__pei386_runtime_relocator",
+        "_do_pseudo_reloc",
+        "_impure_ptr",
+        "__impure_ptr",
+        "__fmode",
+        "_environ",
+        "___dso_handle",
+        // These are the MinGW names that differ from the standard
+        // ones (lacking an extra underscore).
+        "_DllMain@12",
+        "_DllEntryPoint@12",
+        "_DllMainCRTStartup@12",
+    };
+  } else {
+    ExcludeSymbols = {
+        "_NULL_IMPORT_DESCRIPTOR",
+        "_pei386_runtime_relocator",
+        "do_pseudo_reloc",
+        "impure_ptr",
+        "_impure_ptr",
+        "_fmode",
+        "environ",
+        "__dso_handle",
+        // These are the MinGW names that differ from the standard
+        // ones (lacking an extra underscore).
+        "DllMain",
+        "DllEntryPoint",
+        "DllMainCRTStartup",
+    };
+  }
+
+  ExcludeLibs = {
+      "libgcc",
+      "libgcc_s",
+      "libstdc++",
+      "libmingw32",
+      "libmingwex",
+      "libg2c",
+      "libsupc++",
+      "libobjc",
+      "libgcj",
+      "libclang_rt.builtins-aarch64",
+      "libclang_rt.builtins-arm",
+      "libclang_rt.builtins-i386",
+      "libclang_rt.builtins-x86_64",
+      "libc++",
+      "libc++abi",
+      "libunwind",
+      "libmsvcrt",
+      "libucrtbase",
+  };
+  ExcludeObjects = {
+      "crt0.o",
+      "crt1.o",
+      "crt1u.o",
+      "crt2.o",
+      "crt2u.o",
+      "dllcrt1.o",
+      "dllcrt2.o",
+      "gcrt0.o",
+      "gcrt1.o",
+      "gcrt2.o",
+      "crtbegin.o",
+      "crtend.o",
+  };
+}
+
+bool AutoExporter::shouldExport(Defined *Sym) const {
+  if (!Sym || !Sym->isLive() || !Sym->getChunk())
+    return false;
+
+  // Only allow the symbol kinds that make sense to export; in particular,
+  // disallow import symbols.
+  if (!isa<DefinedRegular>(Sym) && !isa<DefinedCommon>(Sym))
+    return false;
+  if (ExcludeSymbols.count(Sym->getName()))
+    return false;
+
+  // Don't export anything that looks like an import symbol (which also can be
+  // a manually defined data symbol with such a name).
+  if (Sym->getName().startswith("__imp_"))
+    return false;
+
+  // If a corresponding __imp_ symbol exists and is defined, don't export it.
+  if (Symtab->find(("__imp_" + Sym->getName()).str()))
+    return false;
+
+  // Check that file is non-null before dereferencing it, symbols not
+  // originating in regular object files probably shouldn't be exported.
+  if (!Sym->getFile())
+    return false;
+
+  StringRef LibName = sys::path::filename(Sym->getFile()->ParentName);
+
+  // Drop the file extension.
+  LibName = LibName.substr(0, LibName.rfind('.'));
+  if (!LibName.empty())
+    return !ExcludeLibs.count(LibName);
+
+  StringRef FileName = sys::path::filename(Sym->getFile()->getName());
+  return !ExcludeObjects.count(FileName);
+}
+
+void coff::writeDefFile(StringRef Name) {
+  std::error_code EC;
+  raw_fd_ostream OS(Name, EC, sys::fs::F_None);
+  if (EC)
+    fatal("cannot open " + Name + ": " + EC.message());
+
+  OS << "EXPORTS\n";
+  for (Export &E : Config->Exports) {
+    OS << "    " << E.ExportName << " "
+       << "@" << E.Ordinal;
+    if (auto *Def = dyn_cast_or_null<Defined>(E.Sym)) {
+      if (Def && Def->getChunk() &&
+          !(Def->getChunk()->getPermissions() & IMAGE_SCN_MEM_EXECUTE))
+        OS << " DATA";
+    }
+    OS << "\n";
+  }
+}