Change the --retain-symbols-file implementation.

It now uses the same infrastructure as symbol versions. This fixes us
creating a dynamic relocation without a corresponding dynamic symbol.

This also means that unlike gold and bfd we keep a STB_LOCAL in the
static symbol table. It seems an odd feature to offer precise control
over what is in a symbol table that is not used by the dynamic
linker. We can bring this back if needed, but it would probably be
better to just have --discard option that tells the linker to keep in
the static symbol table only what is in the dynamic one.

Should fix the eog build.

llvm-svn: 293093

lld/ELF/Config.h

@@ -34,8 +34,8 @@ enum ELFKind {
 // For --build-id.
 enum class BuildIdKind { None, Fast, Md5, Sha1, Hexstring, Uuid };
 
-// For --discard-{all,locals,none} and --retain-symbols-file.
-enum class DiscardPolicy { Default, All, Locals, RetainFile, None };
+// For --discard-{all,locals,none}.
+enum class DiscardPolicy { Default, All, Locals, None };
 
 // For --strip-{all,debug}.
 enum class StripPolicy { None, All, Debug };
@@ -84,7 +84,6 @@ struct Configuration {
   llvm::StringRef OutputFile;
   llvm::StringRef SoName;
   llvm::StringRef Sysroot;
-  llvm::StringSet<> RetainSymbolsFile;
   std::string RPath;
   std::vector<VersionDefinition> VersionDefinitions;
   std::vector<llvm::StringRef> AuxiliaryList;

lld/ELF/Driver.cpp

@@ -614,10 +614,11 @@ void LinkerDriver::readConfigs(opt::InputArgList &Args) {
   // If --retain-symbol-file is used, we'll retail only the symbols listed in
   // the file and discard all others.
   if (auto *Arg = Args.getLastArg(OPT_retain_symbols_file)) {
-    Config->Discard = DiscardPolicy::RetainFile;
+    Config->DefaultSymbolVersion = VER_NDX_LOCAL;
     if (Optional<MemoryBufferRef> Buffer = readFile(Arg->getValue()))
       for (StringRef S : getLines(*Buffer))
-        Config->RetainSymbolsFile.insert(S);
+        Config->VersionScriptGlobals.push_back(
+            {S, /*IsExternCpp*/ false, /*HasWildcard*/ false});
   }
 
   for (auto *Arg : Args.filtered(OPT_export_dynamic_symbol))

lld/ELF/Writer.cpp

@@ -425,12 +425,6 @@ template <class ELFT> static bool includeInSymtab(const SymbolBody &B) {
   if (!B.isLocal() && !B.symbol()->IsUsedInRegularObj)
     return false;
 
-  // If --retain-symbols-file is given, we'll keep only symbols listed in that
-  // file.
-  if (Config->Discard == DiscardPolicy::RetainFile &&
-      !Config->RetainSymbolsFile.count(B.getName()))
-    return false;
-
   if (auto *D = dyn_cast<DefinedRegular<ELFT>>(&B)) {
     // Always include absolute symbols.
     if (!D->Section)

lld/test/ELF/retain-symbols-file.s

@@ -3,15 +3,15 @@
 # RUN: echo "bar" > %t_retain.txt
 # RUN: echo "foo" >> %t_retain.txt
 # RUN: ld.lld -shared --retain-symbols-file=%t_retain.txt %t -o %t2
-# RUN: llvm-readobj -t %t2 | FileCheck %s
+# RUN: llvm-readobj --dyn-symbols %t2 | FileCheck %s
 
 ## Check separate form.
 # RUN: ld.lld -shared --retain-symbols-file %t_retain.txt %t -o %t2
-# RUN: llvm-readobj -t %t2 | FileCheck %s
+# RUN: llvm-readobj --dyn-symbols %t2 | FileCheck %s
 
-# CHECK:      Symbols [
+# CHECK:      DynamicSymbols [
 # CHECK-NEXT:   Symbol {
-# CHECK-NEXT:     Name:  (0)
+# CHECK-NEXT:     Name: @
 # CHECK-NEXT:     Value:
 # CHECK-NEXT:     Size:
 # CHECK-NEXT:     Binding:
@@ -37,6 +37,15 @@
 # CHECK-NEXT:     Other:
 # CHECK-NEXT:     Section: .text
 # CHECK-NEXT:   }
+# CHECK-NEXT:   Symbol {
+# CHECK-NEXT:     Name: und
+# CHECK-NEXT:     Value:
+# CHECK-NEXT:     Size:
+# CHECK-NEXT:     Binding: Global
+# CHECK-NEXT:     Type:
+# CHECK-NEXT:     Other:
+# CHECK-NEXT:     Section: Undefined
+# CHECK-NEXT:   }
 # CHECK-NEXT: ]
 
 .text

lld/test/ELF/retain-und.s

@@ -0,0 +1,18 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
+# RUN: echo  > %t.retain
+# RUN: echo "{ local: *; }; " > %t.script
+# RUN: ld.lld -shared --version-script %t.script %t.o -o %t1.so
+# RUN: ld.lld -shared --retain-symbols-file %t.retain %t.o -o %t2.so
+# RUN: llvm-readobj -r %t1.so | FileCheck %s
+# RUN: llvm-readobj -r %t2.so | FileCheck %s
+
+# CHECK:      Relocations [
+# CHECK-NEXT:   Section ({{.*}}) .rela.dyn {
+# CHECK-NEXT:     0x{{.*}} R_X86_64_64 foo 0x0
+# CHECK-NEXT:   }
+# CHECK-NEXT: ]
+
+.data
+.quad foo
+.weak foo