[Object] Use COFF archive format for import libraries.

[jacek]

Summary

This is similar to D143540 for import libraries. ARM64EC will need it for EC symbol table, but it should be fine for other targets as well and it improves MSVC compatibility. I left mingw case unchanged to be safe, although I think that it wouldn't hurt to change that as well.

[mstorsjo]

The change LGTM. I’m not familiar with what the visible effects in the test are due to this change though; the symbols appear sorted where they previously weren’t?

[jacek]

In D156473#4541272, @mstorsjo wrote:

The change LGTM. I’m not familiar with what the visible effects in the test are due to this change though; the symbols appear sorted where they previously weren’t?

Thanks. Yes, the visible change is that symbols are sorted. All other minor format differences are abstracted by Archive class. I will add a note to the commit message.

[vadikp-intel]

This comment was removed by vadikp-intel.

lld/test/COFF/export.test

 # RUN: FileCheck -check-prefix=CHECK6 %s < %t.log
 
 CHECK6:     duplicate /export option: exportfn2
 CHECK6-NOT: duplicate /export option: exportfn1
 
 # RUN: llvm-nm -M %t.lib | FileCheck --check-prefix=SYMTAB %s
 
 SYMTAB: __imp_exportfn1 in export.test.tmp.DLL
-SYMTAB: exportfn1 in export.test.tmp.DLL
 SYMTAB: __imp_exportfn2 in export.test.tmp.DLL
-SYMTAB: exportfn2 in export.test.tmp.DLL
 SYMTAB: __imp_exportfn3 in export.test.tmp.DLL
+SYMTAB: exportfn1 in export.test.tmp.DLL
+SYMTAB: exportfn2 in export.test.tmp.DLL
 SYMTAB: exportfn3 in export.test.tmp.DLL
 
 # RUN: lld-link /out:%t.dll /dll %t.obj /export:foo=kernel32.foobar
 # RUN: llvm-objdump -p %t.dll | FileCheck --check-prefix=FORWARDER %s
 
 # RUN: echo "EXPORTS foo=kernel32.foobar" > %t.def
 # RUN: lld-link /out:%t.dll /dll %t.obj /def:%t.def
 # RUN: llvm-objdump -p %t.dll | FileCheck --check-prefix=FORWARDER %s

llvm/lib/Object/COFFImportFile.cpp

if (!E.AliasTarget.empty() && *Name != E.AliasTarget) {
       continue;
     }
 
     Members.push_back(
         OF.createShortImport(*Name, E.Ordinal, ImportType, NameType));
   }
 
   return writeArchive(Path, Members, /*WriteSymtab*/ true,
-                      object::Archive::K_GNU,
+                      MinGW ? object::Archive::K_GNU : object::Archive::K_COFF,
                       /*Deterministic*/ true, /*Thin*/ false);
 }
 
 } // namespace object
 } // namespace llvm

llvm/test/tools/llvm-dlltool/coff-exports.def

 ; RUN: llvm-dlltool -m i386:x86-64 --input-def %s --output-lib %t.a
 ; RUN: llvm-readobj %t.a | FileCheck %s
+; RUN: llvm-nm --print-armap %t.a | FileCheck --check-prefix=SYMTAB %s
 ; RUN: llvm-dlltool -m arm64 --input-def %s --output-lib %t.a
 ; RUN: llvm-readobj %t.a | FileCheck %s
+; RUN: llvm-nm --print-armap %t.a | FileCheck --check-prefix=SYMTAB %s
 
 LIBRARY test.dll
 EXPORTS
 TestFunction1
 TestFunction2;
 TestFunction3 ; This is a comment
+AnotherFunction
 
 ; CHECK: File: test.dll
 ; CHECK: Format: COFF-import-file
 ; CHECK: Type: code
 ; CHECK:      Name type: name
 ; CHECK-NEXT: Symbol: __imp_TestFunction1
 ; CHECK-NEXT: Symbol: TestFunction1
 ; CHECK:      Name type: name
 ; CHECK-NEXT: Symbol: __imp_TestFunction2{{$}}
 ; CHECK-NEXT: Symbol: TestFunction2{{$}}
 ; CHECK:      Name type: name
 ; CHECK-NEXT: Symbol: __imp_TestFunction3{{$}}
 ; CHECK-NEXT: Symbol: TestFunction3{{$}}
+
+; SYMTAB: Archive map
+; SYMTAB: TestFunction1 in test.dll
+; SYMTAB: TestFunction2 in test.dll
+; SYMTAB: TestFunction3 in test.dll
+; SYMTAB: AnotherFunction in test.dll

llvm/test/tools/llvm-lib/implibs.test

 Test that import libraries (and the members thereof) can be added to another
 static library.
 
 RUN: rm -rf %t
 RUN: mkdir -p %t
 
 RUN: echo -e "EXPORTS\nMyFunc" > %t/lib.def
 RUN: llvm-dlltool -m i386:x86-64 -l %t/lib.lib -d %t/lib.def -D lib.dll
 RUN: llvm-lib -out:%t/newlib.lib %t/lib.lib
 
 RUN: llvm-ar t %t/newlib.lib | FileCheck %s
 CHECK: lib.dll
 
 Test that import libraries can be created from a def file
 
-RUN: echo -e "NAME lib.dll\nEXPORTS\nMyFunc" > %t/implib.def
+RUN: echo -e "NAME lib.dll\nEXPORTS\nMyFunc\nAnotherFunc" > %t/implib.def
 RUN: llvm-lib -out:%t/implib.lib -def:%t/implib.def -machine:x64
 
 RUN: llvm-ar t %t/implib.lib | FileCheck %s
+
+RUN: llvm-nm --print-armap %t/implib.lib | FileCheck --check-prefix=SYMTAB %s
+SYMTAB:      Archive map
+SYMTAB-NEXT: AnotherFunc in lib.dll
+SYMTAB-NEXT: MyFunc in lib.dll