[llvm] cffe115 - [llvm-dlltool] Use EXPORTAS name type for renamed imports on ARM64EC. (#99346)

[via llvm-commits]

Author: Jacek Caban
Date: 2024-07-22T14:13:21+02:00
New Revision: cffe1153f4466b1602d4778e57c3bd8663cef5ec

URL: https://github.com/llvm/llvm-project/commit/cffe1153f4466b1602d4778e57c3bd8663cef5ec
DIFF: https://github.com/llvm/llvm-project/commit/cffe1153f4466b1602d4778e57c3bd8663cef5ec.diff

LOG: [llvm-dlltool] Use EXPORTAS name type for renamed imports on ARM64EC. (#99346)

Renamed entries are more tricky on ARM64EC than on other targets due
to additional symbols (we need `__imp_aux_*` in addition to `__imp_*`
and both mangled and unmangled symbol thunks). While we could extend
weak aliases to add them, it seems cleaner to just always use EXPORTAS
name type on ARM64EC targets. Unlike other targets, linkers supporting
ARM64EC need to support EXPORTAS, so there is no compatibility problem
with that.

Added: 
    

Modified: 
    llvm/lib/Object/COFFImportFile.cpp
    llvm/test/tools/llvm-dlltool/arm64ec.test

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Object/COFFImportFile.cpp b/llvm/lib/Object/COFFImportFile.cpp
index 2458a53cb6d54..e67b02405a3a1 100644
--- a/llvm/lib/Object/COFFImportFile.cpp
+++ b/llvm/lib/Object/COFFImportFile.cpp
@@ -729,7 +729,10 @@ Error writeImportLibrary(StringRef ImportName, StringRef Path,
         else if (Machine == IMAGE_FILE_MACHINE_I386 &&
                  applyNameType(IMPORT_NAME_NOPREFIX, Name) == E.ImportName)
           NameType = IMPORT_NAME_NOPREFIX;
-        else if (Name == E.ImportName)
+        else if (isArm64EC(M)) {
+          NameType = IMPORT_NAME_EXPORTAS;
+          ExportName = E.ImportName;
+        } else if (Name == E.ImportName)
           NameType = IMPORT_NAME;
         else {
           Deferred D;

diff  --git a/llvm/test/tools/llvm-dlltool/arm64ec.test b/llvm/test/tools/llvm-dlltool/arm64ec.test
index b03b4eaf7b2d0..4ed0f4a4387d6 100644
--- a/llvm/test/tools/llvm-dlltool/arm64ec.test
+++ b/llvm/test/tools/llvm-dlltool/arm64ec.test
@@ -44,6 +44,29 @@ RUN: llvm-nm --print-armap test3.lib | FileCheck --check-prefix=ARMAP2 %s
 RUN: not llvm-dlltool -m arm64 -d test.def -N test2.def -l test4.lib 2>&1 | FileCheck --check-prefix=ERR %s
 ERR: native .def file is supported only on arm64ec target
 
+RUN: llvm-dlltool -m arm64ec -d test3.def -l test3.lib
+RUN: llvm-readobj test3.lib | FileCheck --check-prefix=ALIAS %s
+
+ALIAS:      File: test.dll
+ALIAS-NEXT: Format: COFF-import-file-ARM64EC
+ALIAS-NEXT: Type: code
+ALIAS-NEXT: Name type: export as
+ALIAS-NEXT: Export name: efunc
+ALIAS-NEXT: Symbol: __imp_func
+ALIAS-NEXT: Symbol: func
+ALIAS-NEXT: Symbol: __imp_aux_func
+ALIAS-NEXT: Symbol: #func
+ALIAS-EMPTY:
+ALIAS-NEXT: File: test.dll
+ALIAS-NEXT: Format: COFF-import-file-ARM64EC
+ALIAS-NEXT: Type: code
+ALIAS-NEXT: Name type: export as
+ALIAS-NEXT: Export name: efunc
+ALIAS-NEXT: Symbol: __imp_efunc
+ALIAS-NEXT: Symbol: efunc
+ALIAS-NEXT: Symbol: __imp_aux_efunc
+ALIAS-NEXT: Symbol: #efunc
+
 #--- test.def
 LIBRARY test.dll
 EXPORTS
@@ -53,3 +76,9 @@ EXPORTS
 LIBRARY test.dll
 EXPORTS
     otherfunc
+
+#--- test3.def
+LIBRARY test.dll
+EXPORTS
+    func == efunc
+    efunc