[llvm-readobj][Object][COFF] Print COFF import library symbol export name. (llvm#78769)

cjacek · web-flow · commit a2e5287d5a49 · 2024-02-06T13:47:58.000+01:00
getExportName implementation is based on lld-link. In its current form,
it's mostly about convenience, but it will be more useful for EXPORTAS
support, for which export name is not possible to deduce from other
printed properties.
diff --git 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@Z
 # IMPLIB-NEXT: Symbol: ?GetPathOnDisk@@YA_NPEA_W@Z
 
diff --git 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_@fastcall@8
 # UNDECORATED-IMPLIB-NEXT: fastcall@8
 # UNDECORATED-IMPLIB: Name type: undecorate
+# UNDECORATED-IMPLIB-NEXT: Export name: stdcall
 # UNDECORATED-IMPLIB-NEXT: __imp__stdcall@8
 # UNDECORATED-IMPLIB-NEXT: _stdcall@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@8
 # DECORATED-IMPLIB-NEXT: __imp_@fastcall@8
 # DECORATED-IMPLIB-NEXT: @fastcall@8
 # DECORATED-IMPLIB: Name type: name
+# DECORATED-IMPLIB-NEXT: Export name: _stdcall@8
 # DECORATED-IMPLIB-NEXT: __imp__stdcall@8
 # DECORATED-IMPLIB-NEXT: _stdcall@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@8
 # DECORATED-MINGW-IMPLIB-NEXT: __imp_@fastcall@8
 # DECORATED-MINGW-IMPLIB-NEXT: fastcall@8
 # DECORATED-MINGW-IMPLIB: Name type: noprefix
+# DECORATED-MINGW-IMPLIB-NEXT: Export name: stdcall@8
 # DECORATED-MINGW-IMPLIB-NEXT: __imp__stdcall@8
 # DECORATED-MINGW-IMPLIB-NEXT: _stdcall@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
@@ -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@8
 # DECORATED-IMPLIB-NEXT: __imp_@fastcall@8
 # DECORATED-IMPLIB-NEXT: @fastcall@8
 # DECORATED-IMPLIB: Name type: name
+# DECORATED-IMPLIB-NEXT: Export name: _stdcall@8
 # DECORATED-IMPLIB-NEXT: __imp__stdcall@8
 # DECORATED-IMPLIB-NEXT: _stdcall@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
@@ -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
@@ -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
@@ -14,25 +14,32 @@ OtherStdcallExportName@4=CdeclInternalFunction
 CdeclExportName=StdcallInternalFunction@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@4
 ; CHECK-NEXT: Symbol: _StdcallFunction@4
 ; CHECK:      Name type: undecorate
+; CHECK-NEXT: Export name: FastcallFunction
 ; CHECK-NEXT: Symbol: __imp_@FastcallFunction@4
 ; CHECK-NEXT: Symbol: @FastcallFunction@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@4
 ; CHECK-NM: U _StdcallFunction@4
 ; CHECK:      Name type: undecorate
+; CHECK-NEXT: Export name: StdcallExportName
 ; CHECK-NEXT: Symbol: __imp__StdcallExportName@4{{$}}
 ; CHECK-NEXT: Symbol: _StdcallExportName@4{{$}}
 ; CHECK:      Name type: undecorate
+; CHECK-NEXT: Export name: OtherStdcallExportName
 ; CHECK-NEXT: Symbol: __imp__OtherStdcallExportName@4{{$}}
 ; CHECK-NEXT: Symbol: _OtherStdcallExportName@4{{$}}
 ; 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
@@ -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
@@ -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
@@ -9,9 +9,11 @@ alias == func
 DecoratedFunction@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@4
 ; CHECK-NEXT: Symbol: DecoratedFunction@4
 
diff --git a/llvm/test/tools/llvm-lib/arm64ec-implib.test b/llvm/test/tools/llvm-lib/arm64ec-implib.test
@@ -36,13 +36,15 @@ 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:
 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
@@ -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
@@ -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: ";
