[llvm] [lld] [llvm-lib][llvm-dlltool][Object] Add support for EXPORTAS name types. (PR #78772)

Jacek Caban via llvm-commits llvm-commits at lists.llvm.org
Wed Jan 24 16:31:34 PST 2024


https://github.com/cjacek updated https://github.com/llvm/llvm-project/pull/78772

>From a90235f1c87b31cba368f104c9eb17412cec0585 Mon Sep 17 00:00:00 2001
From: Jacek Caban <jacek at codeweavers.com>
Date: Mon, 4 Sep 2023 16:10:52 +0200
Subject: [PATCH 1/2] [llvm-readobj][Object][COFF] Print COFF import library
 symbol export name.

---
 lld/test/COFF/def-export-cpp.s                |  1 +
 lld/test/COFF/def-export-stdcall.s            | 13 ++++++++++
 lld/test/COFF/dllexport.s                     |  4 +++
 llvm/include/llvm/Object/COFFImportFile.h     |  1 +
 llvm/lib/Object/COFFImportFile.cpp            | 26 +++++++++++++++++++
 .../tools/llvm-dlltool/coff-decorated.def     |  7 +++++
 llvm/test/tools/llvm-dlltool/coff-exports.def |  3 +++
 llvm/test/tools/llvm-dlltool/coff-noname.def  |  1 +
 .../llvm-dlltool/no-leading-underscore.def    |  2 ++
 llvm/test/tools/llvm-lib/arm64ec-implib.test  |  2 ++
 .../tools/llvm-readobj/COFF/file-headers.test |  1 +
 llvm/tools/llvm-readobj/COFFImportDumper.cpp  |  3 +++
 12 files changed, 64 insertions(+)

diff --git a/lld/test/COFF/def-export-cpp.s b/lld/test/COFF/def-export-cpp.s
index e00b35b1c5b39bb..370b8ddba4104b4 100644
--- a/lld/test/COFF/def-export-cpp.s
+++ b/lld/test/COFF/def-export-cpp.s
@@ -10,6 +10,7 @@
 
 # IMPLIB: File: foo.dll
 # IMPLIB: Name type: undecorate
+# IMPLIB-NEXT: Export name: GetPathOnDisk
 # IMPLIB-NEXT: Symbol: __imp_?GetPathOnDisk@@YA_NPEA_W at Z
 # IMPLIB-NEXT: Symbol: ?GetPathOnDisk@@YA_NPEA_W at Z
 
diff --git a/lld/test/COFF/def-export-stdcall.s b/lld/test/COFF/def-export-stdcall.s
index f015e205c74a33d..7e4e04c77cbe7a5 100644
--- a/lld/test/COFF/def-export-stdcall.s
+++ b/lld/test/COFF/def-export-stdcall.s
@@ -6,15 +6,19 @@
 # RUN: llvm-readobj --coff-exports %t.dll | FileCheck -check-prefix UNDECORATED-EXPORTS %s
 
 # UNDECORATED-IMPLIB: Name type: noprefix
+# UNDECORATED-IMPLIB-NEXT: Export name: _underscored
 # UNDECORATED-IMPLIB-NEXT: __imp___underscored
 # UNDECORATED-IMPLIB-NEXT: __underscored
 # UNDECORATED-IMPLIB: Name type: undecorate
+# UNDECORATED-IMPLIB-NEXT: Export name: fastcall
 # UNDECORATED-IMPLIB-NEXT: __imp_ at fastcall@8
 # UNDECORATED-IMPLIB-NEXT: fastcall at 8
 # UNDECORATED-IMPLIB: Name type: undecorate
+# UNDECORATED-IMPLIB-NEXT: Export name: stdcall
 # UNDECORATED-IMPLIB-NEXT: __imp__stdcall at 8
 # UNDECORATED-IMPLIB-NEXT: _stdcall at 8
 # UNDECORATED-IMPLIB: Name type: undecorate
+# UNDECORATED-IMPLIB-NEXT: Export name: vectorcall
 # UNDECORATED-IMPLIB-NEXT: __imp_vectorcall@@8
 # UNDECORATED-IMPLIB-NEXT: vectorcall@@8
 
@@ -30,12 +34,15 @@
 # RUN: llvm-readobj --coff-exports %t.dll | FileCheck -check-prefix DECORATED-EXPORTS %s
 
 # DECORATED-IMPLIB: Name type: name
+# DECORATED-IMPLIB-NEXT: Export name: @fastcall at 8
 # DECORATED-IMPLIB-NEXT: __imp_ at fastcall@8
 # DECORATED-IMPLIB-NEXT: @fastcall at 8
 # DECORATED-IMPLIB: Name type: name
+# DECORATED-IMPLIB-NEXT: Export name: _stdcall at 8
 # DECORATED-IMPLIB-NEXT: __imp__stdcall at 8
 # DECORATED-IMPLIB-NEXT: _stdcall at 8
 # DECORATED-IMPLIB: Name type: name
+# DECORATED-IMPLIB-NEXT: Export name: vectorcall@@8
 # DECORATED-IMPLIB-NEXT: __imp_vectorcall@@8
 # DECORATED-IMPLIB-NEXT: vectorcall@@8
 
@@ -51,14 +58,17 @@
 # RUN: llvm-readobj --coff-exports %t.dll | FileCheck -check-prefix DECORATED-MINGW-EXPORTS %s
 
 # DECORATED-MINGW-IMPLIB: Name type: name
+# DECORATED-MINGW-IMPLIB-NEXT: Export name: @fastcall at 8
 # DECORATED-MINGW-IMPLIB-NEXT: __imp_ at fastcall@8
 # DECORATED-MINGW-IMPLIB-NEXT: fastcall at 8
 # DECORATED-MINGW-IMPLIB: Name type: noprefix
+# DECORATED-MINGW-IMPLIB-NEXT: Export name: stdcall at 8
 # DECORATED-MINGW-IMPLIB-NEXT: __imp__stdcall at 8
 # DECORATED-MINGW-IMPLIB-NEXT: _stdcall at 8
 # GNU tools don't support vectorcall, but this test is just to track that
 # lld's behaviour remains consistent over time.
 # DECORATED-MINGW-IMPLIB: Name type: name
+# DECORATED-MINGW-IMPLIB-NEXT: Export name: vectorcall@@8
 # DECORATED-MINGW-IMPLIB-NEXT: __imp_vectorcall@@8
 # DECORATED-MINGW-IMPLIB-NEXT: vectorcall@@8
 
@@ -75,14 +85,17 @@
 # RUN: llvm-readobj --coff-exports %t.dll | FileCheck -check-prefix MINGW-KILL-AT-EXPORTS %s
 
 # MINGW-KILL-AT-IMPLIB: Name type: noprefix
+# MINGW-KILL-AT-IMPLIB: Export name: fastcall
 # MINGW-KILL-AT-IMPLIB: __imp__fastcall
 # MINGW-KILL-AT-IMPLIB-NEXT: _fastcall
 # MINGW-KILL-AT-IMPLIB: Name type: noprefix
+# MINGW-KILL-AT-IMPLIB-NEXT: Export name: stdcall
 # MINGW-KILL-AT-IMPLIB-NEXT: __imp__stdcall
 # MINGW-KILL-AT-IMPLIB-NEXT: _stdcall
 # GNU tools don't support vectorcall, but this test is just to track that
 # lld's behaviour remains consistent over time.
 # MINGW-KILL-AT-IMPLIB: Name type: noprefix
+# MINGW-KILL-AT-IMPLIB-NEXT: Export name: vectorcall
 # MINGW-KILL-AT-IMPLIB-NEXT: __imp__vectorcall
 # MINGW-KILL-AT-IMPLIB-NEXT: _vectorcall
 
diff --git a/lld/test/COFF/dllexport.s b/lld/test/COFF/dllexport.s
index a238b70ce1b4f69..b04ebc3a33c3e2d 100644
--- a/lld/test/COFF/dllexport.s
+++ b/lld/test/COFF/dllexport.s
@@ -6,15 +6,19 @@
 # RUN: llvm-readobj --coff-exports %t.dll | FileCheck -check-prefix DECORATED-EXPORTS %s
 
 # DECORATED-IMPLIB: Name type: name
+# DECORATED-IMPLIB-NEXT: Export name: @fastcall at 8
 # DECORATED-IMPLIB-NEXT: __imp_ at fastcall@8
 # DECORATED-IMPLIB-NEXT: @fastcall at 8
 # DECORATED-IMPLIB: Name type: name
+# DECORATED-IMPLIB-NEXT: Export name: _stdcall at 8
 # DECORATED-IMPLIB-NEXT: __imp__stdcall at 8
 # DECORATED-IMPLIB-NEXT: _stdcall at 8
 # DECORATED-IMPLIB: Name type: noprefix
+# DECORATED-IMPLIB-NEXT: Export name: _underscored
 # DECORATED-IMPLIB-NEXT: __imp___underscored
 # DECORATED-IMPLIB-NEXT: __underscored
 # DECORATED-IMPLIB: Name type: name
+# DECORATED-IMPLIB-NEXT: Export name: vectorcall@@8
 # DECORATED-IMPLIB-NEXT: __imp_vectorcall@@8
 # DECORATED-IMPLIB-NEXT: vectorcall@@8
 
diff --git a/llvm/include/llvm/Object/COFFImportFile.h b/llvm/include/llvm/Object/COFFImportFile.h
index edc836ff0348cb2..45a4a795fd19034 100644
--- a/llvm/include/llvm/Object/COFFImportFile.h
+++ b/llvm/include/llvm/Object/COFFImportFile.h
@@ -66,6 +66,7 @@ class COFFImportFile : public SymbolicFile {
   uint16_t getMachine() const { return getCOFFImportHeader()->Machine; }
 
   StringRef getFileFormatName() const;
+  StringRef getExportName() const;
 
 private:
   bool isData() const {
diff --git a/llvm/lib/Object/COFFImportFile.cpp b/llvm/lib/Object/COFFImportFile.cpp
index 60556c149bf735b..d7d26f4f4180c37 100644
--- a/llvm/lib/Object/COFFImportFile.cpp
+++ b/llvm/lib/Object/COFFImportFile.cpp
@@ -52,6 +52,32 @@ StringRef COFFImportFile::getFileFormatName() const {
   }
 }
 
+StringRef COFFImportFile::getExportName() const {
+  const coff_import_header *hdr = getCOFFImportHeader();
+  StringRef name = Data.getBuffer().substr(sizeof(*hdr)).split('\0').first;
+
+  auto ltrim1 = [](StringRef s, StringRef chars) {
+    return !s.empty() && chars.contains(s[0]) ? s.substr(1) : s;
+  };
+
+  switch (hdr->getNameType()) {
+  case IMPORT_ORDINAL:
+    name = "";
+    break;
+  case IMPORT_NAME_NOPREFIX:
+    name = ltrim1(name, "?@_");
+    break;
+  case IMPORT_NAME_UNDECORATE:
+    name = ltrim1(name, "?@_");
+    name = name.substr(0, name.find('@'));
+    break;
+  default:
+    break;
+  }
+
+  return name;
+}
+
 static uint16_t getImgRelRelocation(MachineTypes Machine) {
   switch (Machine) {
   default:
diff --git a/llvm/test/tools/llvm-dlltool/coff-decorated.def b/llvm/test/tools/llvm-dlltool/coff-decorated.def
index 856804686168b17..fc81f23d09d6c48 100644
--- a/llvm/test/tools/llvm-dlltool/coff-decorated.def
+++ b/llvm/test/tools/llvm-dlltool/coff-decorated.def
@@ -14,25 +14,32 @@ OtherStdcallExportName at 4=CdeclInternalFunction
 CdeclExportName=StdcallInternalFunction at 4
 
 ; CHECK:      Name type: noprefix
+; CHECK-NEXT: Export name: CdeclFunction
 ; CHECK-NEXT: Symbol: __imp__CdeclFunction
 ; CHECK-NEXT: Symbol: _CdeclFunction
 ; CHECK:      Name type: undecorate
+; CHECK-NEXT: Export name: StdcallFunction
 ; CHECK-NEXT: Symbol: __imp__StdcallFunction at 4
 ; CHECK-NEXT: Symbol: _StdcallFunction at 4
 ; CHECK:      Name type: undecorate
+; CHECK-NEXT: Export name: FastcallFunction
 ; CHECK-NEXT: Symbol: __imp_ at FastcallFunction@4
 ; CHECK-NEXT: Symbol: @FastcallFunction at 4
 ; CHECK:      Name type: name
+; CHECK-NEXT: Export name: ??_7exception@@6B@
 ; CHECK-NEXT: Symbol: __imp_??_7exception@@6B@
 ; CHECK-NEXT: Symbol: ??_7exception@@6B@
 ; CHECK-NM: W _StdcallAlias at 4
 ; CHECK-NM: U _StdcallFunction at 4
 ; CHECK:      Name type: undecorate
+; CHECK-NEXT: Export name: StdcallExportName
 ; CHECK-NEXT: Symbol: __imp__StdcallExportName at 4{{$}}
 ; CHECK-NEXT: Symbol: _StdcallExportName at 4{{$}}
 ; CHECK:      Name type: undecorate
+; CHECK-NEXT: Export name: OtherStdcallExportName
 ; CHECK-NEXT: Symbol: __imp__OtherStdcallExportName at 4{{$}}
 ; CHECK-NEXT: Symbol: _OtherStdcallExportName at 4{{$}}
 ; CHECK:      Name type: noprefix
+; CHECK-NEXT: Export name: CdeclExportName
 ; CHECK-NEXT: Symbol: __imp__CdeclExportName
 ; CHECK-NEXT: Symbol: _CdeclExportName
diff --git a/llvm/test/tools/llvm-dlltool/coff-exports.def b/llvm/test/tools/llvm-dlltool/coff-exports.def
index 57c557446021565..267424db1b8c1da 100644
--- a/llvm/test/tools/llvm-dlltool/coff-exports.def
+++ b/llvm/test/tools/llvm-dlltool/coff-exports.def
@@ -17,12 +17,15 @@ AnotherFunction
 ; CHECK-ARM64: Format: COFF-import-file-ARM64
 ; CHECK: Type: code
 ; CHECK:      Name type: name
+; CHECK-NEXT: Export name: TestFunction1
 ; CHECK-NEXT: Symbol: __imp_TestFunction1
 ; CHECK-NEXT: Symbol: TestFunction1
 ; CHECK:      Name type: name
+; CHECK-NEXT: Export name: TestFunction2
 ; CHECK-NEXT: Symbol: __imp_TestFunction2{{$}}
 ; CHECK-NEXT: Symbol: TestFunction2{{$}}
 ; CHECK:      Name type: name
+; CHECK-NEXT: Export name: TestFunction3
 ; CHECK-NEXT: Symbol: __imp_TestFunction3{{$}}
 ; CHECK-NEXT: Symbol: TestFunction3{{$}}
 
diff --git a/llvm/test/tools/llvm-dlltool/coff-noname.def b/llvm/test/tools/llvm-dlltool/coff-noname.def
index 27e60efbd2d8027..7cb05846ce28a20 100644
--- a/llvm/test/tools/llvm-dlltool/coff-noname.def
+++ b/llvm/test/tools/llvm-dlltool/coff-noname.def
@@ -12,5 +12,6 @@ ByNameFunction
 ; CHECK-NEXT: Symbol: __imp__ByOrdinalFunction
 ; CHECK-NEXT: Symbol: _ByOrdinalFunction
 ; CHECK:      Name type: noprefix
+; CHECK-NEXT: Export name: ByNameFunction
 ; CHECK-NEXT: Symbol: __imp__ByNameFunction
 ; CHECK-NEXT: Symbol: _ByNameFunction
diff --git a/llvm/test/tools/llvm-dlltool/no-leading-underscore.def b/llvm/test/tools/llvm-dlltool/no-leading-underscore.def
index 6b78e15d2b5f695..9c5e77ca29a8212 100644
--- a/llvm/test/tools/llvm-dlltool/no-leading-underscore.def
+++ b/llvm/test/tools/llvm-dlltool/no-leading-underscore.def
@@ -9,9 +9,11 @@ alias == func
 DecoratedFunction at 4
 
 ; CHECK:      Name type: name
+; CHECK-NEXT: Export name: func
 ; CHECK-NEXT: Symbol: __imp_func
 ; CHECK-NEXT: Symbol: func
 ; CHECK:      Name type: undecorate
+; CHECK-NEXT: Export name: DecoratedFunction
 ; CHECK-NEXT: Symbol: __imp_DecoratedFunction at 4
 ; CHECK-NEXT: Symbol: DecoratedFunction at 4
 
diff --git a/llvm/test/tools/llvm-lib/arm64ec-implib.test b/llvm/test/tools/llvm-lib/arm64ec-implib.test
index 2672f8d38b7f704..4250c775daa6012 100644
--- a/llvm/test/tools/llvm-lib/arm64ec-implib.test
+++ b/llvm/test/tools/llvm-lib/arm64ec-implib.test
@@ -36,6 +36,7 @@ READOBJ-NEXT: File: test.dll
 READOBJ-NEXT: Format: COFF-import-file-ARM64EC
 READOBJ-NEXT: Type: code
 READOBJ-NEXT: Name type: name
+READOBJ-NEXT: Export name: funcexp
 READOBJ-NEXT: Symbol: __imp_funcexp
 READOBJ-NEXT: Symbol: funcexp
 READOBJ-EMPTY:
@@ -43,6 +44,7 @@ READOBJ-NEXT: File: test.dll
 READOBJ-NEXT: Format: COFF-import-file-ARM64EC
 READOBJ-NEXT: Type: data
 READOBJ-NEXT: Name type: name
+READOBJ-NEXT: Export name: dataexp
 READOBJ-NEXT: Symbol: __imp_dataexp
 
 Creating a new lib containing the existing lib:
diff --git a/llvm/test/tools/llvm-readobj/COFF/file-headers.test b/llvm/test/tools/llvm-readobj/COFF/file-headers.test
index b83a6cf5b972b34..32f39e196b0001d 100644
--- a/llvm/test/tools/llvm-readobj/COFF/file-headers.test
+++ b/llvm/test/tools/llvm-readobj/COFF/file-headers.test
@@ -323,6 +323,7 @@ symbols:
 #      IMPORTLIB:Format: COFF-import-file-i386
 # IMPORTLIB-NEXT:Type: code
 # IMPORTLIB-NEXT:Name type: noprefix
+# IMPORTLIB-NEXT:Export name: func
 # IMPORTLIB-NEXT:Symbol: __imp__func
 # IMPORTLIB-NEXT:Symbol: _func
 # IMPORTLIB-NOT:{{.}}
diff --git a/llvm/tools/llvm-readobj/COFFImportDumper.cpp b/llvm/tools/llvm-readobj/COFFImportDumper.cpp
index 8aedc310ae3a9fe..656ca32f03a77df 100644
--- a/llvm/tools/llvm-readobj/COFFImportDumper.cpp
+++ b/llvm/tools/llvm-readobj/COFFImportDumper.cpp
@@ -47,6 +47,9 @@ void dumpCOFFImportFile(const COFFImportFile *File, ScopedPrinter &Writer) {
     break;
   }
 
+  if (H->getNameType() != COFF::IMPORT_ORDINAL)
+    Writer.printString("Export name", File->getExportName());
+
   for (const object::BasicSymbolRef &Sym : File->symbols()) {
     raw_ostream &OS = Writer.startLine();
     OS << "Symbol: ";

>From 4107b819ae3b57505f9e7a39f185be25ec59559e Mon Sep 17 00:00:00 2001
From: Jacek Caban <jacek at codeweavers.com>
Date: Wed, 17 Jan 2024 16:12:29 +0100
Subject: [PATCH 2/2] [llvm-lib][llvm-dlltool][Object] Add support for EXPORTAS
 name types.

---
 llvm/include/llvm/BinaryFormat/COFF.h        |  5 +-
 llvm/include/llvm/Object/COFFImportFile.h    |  4 +
 llvm/lib/Object/COFFImportFile.cpp           | 66 +++++++++-----
 llvm/lib/Object/COFFModuleDefinition.cpp     | 13 ++-
 llvm/test/tools/llvm-lib/exportas.test       | 94 ++++++++++++++++++++
 llvm/tools/llvm-readobj/COFFImportDumper.cpp |  3 +
 6 files changed, 162 insertions(+), 23 deletions(-)
 create mode 100644 llvm/test/tools/llvm-lib/exportas.test

diff --git a/llvm/include/llvm/BinaryFormat/COFF.h b/llvm/include/llvm/BinaryFormat/COFF.h
index 522ee37da6e830c..72461d0d9c316a3 100644
--- a/llvm/include/llvm/BinaryFormat/COFF.h
+++ b/llvm/include/llvm/BinaryFormat/COFF.h
@@ -716,7 +716,10 @@ enum ImportNameType : unsigned {
   IMPORT_NAME_NOPREFIX = 2,
   /// The import name is the public symbol name, but skipping the leading ?,
   /// @, or optionally _, and truncating at the first @.
-  IMPORT_NAME_UNDECORATE = 3
+  IMPORT_NAME_UNDECORATE = 3,
+  /// The import name is specified as a separate string in the import library
+  /// object file.
+  IMPORT_NAME_EXPORTAS = 4
 };
 
 enum class GuardFlags : uint32_t {
diff --git a/llvm/include/llvm/Object/COFFImportFile.h b/llvm/include/llvm/Object/COFFImportFile.h
index 45a4a795fd19034..7c5846e9c044e39 100644
--- a/llvm/include/llvm/Object/COFFImportFile.h
+++ b/llvm/include/llvm/Object/COFFImportFile.h
@@ -92,6 +92,10 @@ struct COFFShortExport {
   /// file, this is "baz" in "EXPORTS\nfoo = bar == baz".
   std::string AliasTarget;
 
+  /// Specifies EXPORTAS name. In a .def file, this is "bar" in
+  /// "EXPORTS\nfoo EXPORTAS bar".
+  std::string ExportAs;
+
   uint16_t Ordinal = 0;
   bool Noname = false;
   bool Data = false;
diff --git a/llvm/lib/Object/COFFImportFile.cpp b/llvm/lib/Object/COFFImportFile.cpp
index d7d26f4f4180c37..51e6274dcf235cc 100644
--- a/llvm/lib/Object/COFFImportFile.cpp
+++ b/llvm/lib/Object/COFFImportFile.cpp
@@ -71,6 +71,12 @@ StringRef COFFImportFile::getExportName() const {
     name = ltrim1(name, "?@_");
     name = name.substr(0, name.find('@'));
     break;
+  case IMPORT_NAME_EXPORTAS: {
+    // Skip DLL name
+    name = Data.getBuffer().substr(sizeof(*hdr) + name.size() + 1);
+    name = name.split('\0').second.split('\0').first;
+    break;
+  }
   default:
     break;
   }
@@ -209,6 +215,7 @@ class ObjectFactory {
   // Library Format.
   NewArchiveMember createShortImport(StringRef Sym, uint16_t Ordinal,
                                      ImportType Type, ImportNameType NameType,
+                                     StringRef ExportName,
                                      MachineTypes Machine);
 
   // Create a weak external file which is described in PE/COFF Aux Format 3.
@@ -500,12 +507,13 @@ NewArchiveMember ObjectFactory::createNullThunk(std::vector<uint8_t> &Buffer) {
   return {MemoryBufferRef{F, ImportName}};
 }
 
-NewArchiveMember ObjectFactory::createShortImport(StringRef Sym,
-                                                  uint16_t Ordinal,
-                                                  ImportType ImportType,
-                                                  ImportNameType NameType,
-                                                  MachineTypes Machine) {
+NewArchiveMember
+ObjectFactory::createShortImport(StringRef Sym, uint16_t Ordinal,
+                                 ImportType ImportType, ImportNameType NameType,
+                                 StringRef ExportName, MachineTypes Machine) {
   size_t ImpSize = ImportName.size() + Sym.size() + 2; // +2 for NULs
+  if (!ExportName.empty())
+    ImpSize += ExportName.size() + 1;
   size_t Size = sizeof(coff_import_header) + ImpSize;
   char *Buf = Alloc.Allocate<char>(Size);
   memset(Buf, 0, Size);
@@ -525,6 +533,10 @@ NewArchiveMember ObjectFactory::createShortImport(StringRef Sym,
   memcpy(P, Sym.data(), Sym.size());
   P += Sym.size() + 1;
   memcpy(P, ImportName.data(), ImportName.size());
+  if (!ExportName.empty()) {
+    P += ImportName.size() + 1;
+    memcpy(P, ExportName.data(), ExportName.size());
+  }
 
   return {MemoryBufferRef(StringRef(Buf, Size), ImportName)};
 }
@@ -641,27 +653,39 @@ Error writeImportLibrary(StringRef ImportName, StringRef Path,
       ImportType = IMPORT_CONST;
 
     StringRef SymbolName = E.SymbolName.empty() ? E.Name : E.SymbolName;
-    ImportNameType NameType = E.Noname
-                                  ? IMPORT_ORDINAL
-                                  : getNameType(SymbolName, E.Name,
-                                                Machine, MinGW);
-    Expected<std::string> Name = E.ExtName.empty()
-                                     ? std::string(SymbolName)
-                                     : replace(SymbolName, E.Name, E.ExtName);
-
-    if (!Name)
-      return Name.takeError();
-
-    if (!E.AliasTarget.empty() && *Name != E.AliasTarget) {
+    std::string Name;
+
+    if (E.ExtName.empty()) {
+      Name = std::string(SymbolName);
+    } else {
+      Expected<std::string> ReplacedName =
+          replace(SymbolName, E.Name, E.ExtName);
+      if (!ReplacedName)
+        return ReplacedName.takeError();
+      Name.swap(*ReplacedName);
+    }
+
+    if (!E.AliasTarget.empty() && Name != E.AliasTarget) {
       Members.push_back(
-          OF.createWeakExternal(E.AliasTarget, *Name, false, Machine));
+          OF.createWeakExternal(E.AliasTarget, Name, false, Machine));
       Members.push_back(
-          OF.createWeakExternal(E.AliasTarget, *Name, true, Machine));
+          OF.createWeakExternal(E.AliasTarget, Name, true, Machine));
       continue;
     }
 
-    Members.push_back(
-        OF.createShortImport(*Name, E.Ordinal, ImportType, NameType, Machine));
+    ImportNameType NameType;
+    std::string ExportName;
+    if (E.Noname) {
+      NameType = IMPORT_ORDINAL;
+    } else if (!E.ExportAs.empty()) {
+      NameType = IMPORT_NAME_EXPORTAS;
+      ExportName = E.ExportAs;
+    } else {
+      NameType = getNameType(SymbolName, E.Name, Machine, MinGW);
+    }
+
+    Members.push_back(OF.createShortImport(Name, E.Ordinal, ImportType,
+                                           NameType, ExportName, Machine));
   }
 
   return writeArchive(Path, Members, SymtabWritingMode::NormalSymtab,
diff --git a/llvm/lib/Object/COFFModuleDefinition.cpp b/llvm/lib/Object/COFFModuleDefinition.cpp
index 648f01f823d007a..f60dd49793685fa 100644
--- a/llvm/lib/Object/COFFModuleDefinition.cpp
+++ b/llvm/lib/Object/COFFModuleDefinition.cpp
@@ -39,6 +39,7 @@ enum Kind {
   KwConstant,
   KwData,
   KwExports,
+  KwExportAs,
   KwHeapsize,
   KwLibrary,
   KwName,
@@ -118,6 +119,7 @@ class Lexer {
                    .Case("CONSTANT", KwConstant)
                    .Case("DATA", KwData)
                    .Case("EXPORTS", KwExports)
+                   .Case("EXPORTAS", KwExportAs)
                    .Case("HEAPSIZE", KwHeapsize)
                    .Case("LIBRARY", KwLibrary)
                    .Case("NAME", KwName)
@@ -286,7 +288,16 @@ class Parser {
           E.AliasTarget = std::string("_").append(E.AliasTarget);
         continue;
       }
-      unget();
+      // EXPORTAS must be at the end of export definition
+      if (Tok.K == KwExportAs) {
+        read();
+        if (Tok.K == Eof)
+          return createError(
+              "unexpected end of file, EXPORTAS identifier expected");
+        E.ExportAs = std::string(Tok.Value);
+      } else {
+        unget();
+      }
       Info.Exports.push_back(E);
       return Error::success();
     }
diff --git a/llvm/test/tools/llvm-lib/exportas.test b/llvm/test/tools/llvm-lib/exportas.test
new file mode 100644
index 000000000000000..f6e845ca174664a
--- /dev/null
+++ b/llvm/test/tools/llvm-lib/exportas.test
@@ -0,0 +1,94 @@
+Test EXPORTAS in importlibs.
+
+RUN: split-file %s %t.dir && cd %t.dir
+RUN: llvm-lib -machine:amd64 -def:test.def -out:test.lib
+
+RUN: llvm-nm --print-armap test.lib | FileCheck --check-prefix=ARMAP %s
+
+ARMAP:      Archive map
+ARMAP-NEXT: __IMPORT_DESCRIPTOR_test in test.dll
+ARMAP-NEXT: __NULL_IMPORT_DESCRIPTOR in test.dll
+ARMAP-NEXT: __imp_func in test.dll
+ARMAP-NEXT: __imp_func2 in test.dll
+ARMAP-NEXT: __imp_func3 in test.dll
+ARMAP-NEXT: __imp_mydata in test.dll
+ARMAP-NEXT: func in test.dll
+ARMAP-NEXT: func2 in test.dll
+ARMAP-NEXT: func3 in test.dll
+ARMAP-NEXT: test_NULL_THUNK_DATA in test.dll
+
+RUN: llvm-readobj test.lib | FileCheck --check-prefix=READOBJ %s
+
+READOBJ:      File: test.lib(test.dll)
+READOBJ-NEXT: Format: COFF-x86-64
+READOBJ-NEXT: Arch: x86_64
+READOBJ-NEXT: AddressSize: 64bit
+READOBJ-EMPTY:
+READOBJ-NEXT: File: test.lib(test.dll)
+READOBJ-NEXT: Format: COFF-x86-64
+READOBJ-NEXT: Arch: x86_64
+READOBJ-NEXT: AddressSize: 64bit
+READOBJ-EMPTY:
+READOBJ-NEXT: File: test.lib(test.dll)
+READOBJ-NEXT: Format: COFF-x86-64
+READOBJ-NEXT: Arch: x86_64
+READOBJ-NEXT: AddressSize: 64bit
+READOBJ-EMPTY:
+READOBJ-NEXT: File: test.dll
+READOBJ-NEXT: Format: COFF-import-file-x86-64
+READOBJ-NEXT: Type: code
+READOBJ-NEXT: Name type: export as
+READOBJ-NEXT: Export name: expfunc
+READOBJ-NEXT: Symbol: __imp_func
+READOBJ-NEXT: Symbol: func
+READOBJ-EMPTY:
+READOBJ-NEXT: File: test.dll
+READOBJ-NEXT: Format: COFF-import-file-x86-64
+READOBJ-NEXT: Type: data
+READOBJ-NEXT: Name type: export as
+READOBJ-NEXT: Export name: expdata
+READOBJ-NEXT: Symbol: __imp_mydata
+READOBJ-EMPTY:
+READOBJ-NEXT: File: test.dll
+READOBJ-NEXT: Format: COFF-import-file-x86-64
+READOBJ-NEXT: Type: code
+READOBJ-NEXT: Name type: export as
+READOBJ-NEXT: Export name: expfunc2
+READOBJ-NEXT: Symbol: __imp_func2
+READOBJ-NEXT: Symbol: func2
+READOBJ-EMPTY:
+READOBJ-NEXT: File: test.dll
+READOBJ-NEXT: Format: COFF-import-file-x86-64
+READOBJ-NEXT: Type: code
+READOBJ-NEXT: Name type: export as
+READOBJ-NEXT: Export name: expfunc3
+READOBJ-NEXT: Symbol: __imp_func3
+READOBJ-NEXT: Symbol: func3
+
+
+EXPORTAS must be at the end of entry declaration.
+RUN: not llvm-lib -machine:amd64 -def:test2.def -out:test2.lib 2>&1 \
+RUN:              | FileCheck --check-prefix=ERROR %s
+RUN: not llvm-lib -machine:amd64 -def:test3.def -out:test3.lib 2>&1 \
+RUN:              | FileCheck --check-prefix=ERROR %s
+ERROR: Invalid data was encountered while parsing the file
+
+
+#--- test.def
+LIBRARY test.dll
+EXPORTS
+        func EXPORTAS expfunc
+        mydata DATA EXPORTAS expdata
+        func2 = myfunc2 EXPORTAS expfunc2
+        func3 = otherdll.otherfunc3 EXPORTAS expfunc3
+
+#--- test2.def
+LIBRARY test.dll
+EXPORTS
+        func EXPORTAS expfunc
+        mydata EXPORTAS expdata DATA
+
+#--- test3.def
+LIBRARY test.dll
+EXPORTS
+        mydata EXPORTAS
diff --git a/llvm/tools/llvm-readobj/COFFImportDumper.cpp b/llvm/tools/llvm-readobj/COFFImportDumper.cpp
index 656ca32f03a77df..0ab2a17655653e4 100644
--- a/llvm/tools/llvm-readobj/COFFImportDumper.cpp
+++ b/llvm/tools/llvm-readobj/COFFImportDumper.cpp
@@ -45,6 +45,9 @@ void dumpCOFFImportFile(const COFFImportFile *File, ScopedPrinter &Writer) {
   case COFF::IMPORT_NAME_UNDECORATE:
     Writer.printString("Name type", "undecorate");
     break;
+  case COFF::IMPORT_NAME_EXPORTAS:
+    Writer.printString("Name type", "export as");
+    break;
   }
 
   if (H->getNameType() != COFF::IMPORT_ORDINAL)



More information about the llvm-commits mailing list