Vendor import of lld release_40 branch r292732:

https://llvm.org/svn/llvm-project/lld/branches/release_40@292732

ELF/SymbolTable.cpp

@@ -140,7 +140,7 @@ template <class ELFT>
 DefinedRegular<ELFT> *SymbolTable<ELFT>::addIgnored(StringRef Name,
                                                     uint8_t Visibility) {
   SymbolBody *S = find(Name);
-  if (!S || !S->isUndefined())
+  if (!S || S->isInCurrentDSO())
     return nullptr;
   return addAbsolute(Name, Visibility);
 }
@@ -283,7 +283,7 @@ static int compareDefined(Symbol *S, bool WasInserted, uint8_t Binding) {
   if (WasInserted)
     return 1;
   SymbolBody *Body = S->body();
-  if (Body->isLazy() || Body->isUndefined() || Body->isShared())
+  if (Body->isLazy() || !Body->isInCurrentDSO())
     return 1;
   if (Binding == STB_WEAK)
     return -1;
@@ -426,12 +426,8 @@ void SymbolTable<ELFT>::addShared(SharedFile<ELFT> *F, StringRef Name,
   std::tie(S, WasInserted) =
       insert(Name, Sym.getType(), STV_DEFAULT, /*CanOmitFromDynSym*/ true, F);
   // Make sure we preempt DSO symbols with default visibility.
-  if (Sym.getVisibility() == STV_DEFAULT) {
+  if (Sym.getVisibility() == STV_DEFAULT)
     S->ExportDynamic = true;
-    // Exporting preempting symbols takes precedence over linker scripts.
-    if (S->VersionId == VER_NDX_LOCAL)
-      S->VersionId = VER_NDX_GLOBAL;
-  }
   if (WasInserted || isa<Undefined<ELFT>>(S->body())) {
     replaceBody<SharedSymbol<ELFT>>(S, F, Name, Sym, Verdef);
     if (!S->isWeak())
@@ -467,6 +463,14 @@ template <class ELFT> SymbolBody *SymbolTable<ELFT>::find(StringRef Name) {
   return SymVector[V.Idx]->body();
 }
 
+template <class ELFT>
+SymbolBody *SymbolTable<ELFT>::findInCurrentDSO(StringRef Name) {
+  if (SymbolBody *S = find(Name))
+    if (S->isInCurrentDSO())
+      return S;
+  return nullptr;
+}
+
 template <class ELFT>
 void SymbolTable<ELFT>::addLazyArchive(ArchiveFile *F,
                                        const object::Archive::Symbol Sym) {

ELF/SymbolTable.h

@@ -82,6 +82,7 @@ template <class ELFT> class SymbolTable {
   void scanVersionScript();
 
   SymbolBody *find(StringRef Name);
+  SymbolBody *findInCurrentDSO(StringRef Name);
 
   void trace(StringRef Name);
   void wrap(StringRef Name);

ELF/Symbols.cpp

@@ -203,8 +203,8 @@ void SymbolBody::parseSymbolVersion() {
   // Truncate the symbol name so that it doesn't include the version string.
   Name = {S.data(), Pos};
 
-  // If this is an undefined or shared symbol it is not a definition.
-  if (isUndefined() || isShared())
+  // If this is not in this DSO, it is not a definition.
+  if (!isInCurrentDSO())
     return;
 
   // '@@' in a symbol name means the default version.
@@ -299,7 +299,8 @@ uint8_t Symbol::computeBinding() const {
     return Binding;
   if (Visibility != STV_DEFAULT && Visibility != STV_PROTECTED)
     return STB_LOCAL;
-  if (VersionId == VER_NDX_LOCAL && !body()->isUndefined())
+  const SymbolBody *Body = body();
+  if (VersionId == VER_NDX_LOCAL && Body->isInCurrentDSO())
     return STB_LOCAL;
   if (Config->NoGnuUnique && Binding == STB_GNU_UNIQUE)
     return STB_GLOBAL;

ELF/Symbols.h

@@ -67,6 +67,7 @@ class SymbolBody {
     return SymbolKind == LazyArchiveKind || SymbolKind == LazyObjectKind;
   }
   bool isShared() const { return SymbolKind == SharedKind; }
+  bool isInCurrentDSO() const { return !isUndefined() && !isShared(); }
   bool isLocal() const { return IsLocal; }
   bool isPreemptible() const;
   StringRef getName() const { return Name; }

ELF/SyntheticSections.cpp

@@ -883,9 +883,9 @@ template <class ELFT> void DynamicSection<ELFT>::finalize() {
     add({DT_FINI_ARRAYSZ, Out<ELFT>::FiniArray, Entry::SecSize});
   }
 
-  if (SymbolBody *B = Symtab<ELFT>::X->find(Config->Init))
+  if (SymbolBody *B = Symtab<ELFT>::X->findInCurrentDSO(Config->Init))
     add({DT_INIT, B});
-  if (SymbolBody *B = Symtab<ELFT>::X->find(Config->Fini))
+  if (SymbolBody *B = Symtab<ELFT>::X->findInCurrentDSO(Config->Fini))
     add({DT_FINI, B});
 
   bool HasVerNeed = In<ELFT>::VerNeed->getNeedNum() != 0;

ELF/Writer.cpp

@@ -641,7 +641,7 @@ static void addOptionalSynthetic(StringRef Name, OutputSectionBase *Sec,
                                  typename ELFT::uint Val,
                                  uint8_t StOther = STV_HIDDEN) {
   if (SymbolBody *S = Symtab<ELFT>::X->find(Name))
-    if (S->isUndefined() || S->isShared())
+    if (!S->isInCurrentDSO())
       Symtab<ELFT>::X->addSynthetic(Name, Sec, Val, StOther);
 }
 
@@ -661,7 +661,7 @@ static Symbol *addOptionalRegular(StringRef Name, InputSectionBase<ELFT> *IS,
   SymbolBody *S = Symtab<ELFT>::X->find(Name);
   if (!S)
     return nullptr;
-  if (!S->isUndefined() && !S->isShared())
+  if (S->isInCurrentDSO())
     return S->symbol();
   return addRegular(Name, IS, Value);
 }

test/ELF/Inputs/resolution-end.s

@@ -0,0 +1,2 @@
+.data
+        .quad _end

test/ELF/gc-sections-shared.s

@@ -19,15 +19,6 @@
 # CHECK-NEXT:     Section: Undefined (0x0)
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Symbol {
-# CHECK-NEXT:     Name: bar
-# CHECK-NEXT:     Value:
-# CHECK-NEXT:     Size:
-# CHECK-NEXT:     Binding: Global
-# CHECK-NEXT:     Type:
-# CHECK-NEXT:     Other:
-# CHECK-NEXT:     Section: .text
-# CHECK-NEXT:   }
-# CHECK-NEXT:   Symbol {
 # CHECK-NEXT:     Name: bar2
 # CHECK-NEXT:     Value:
 # CHECK-NEXT:     Size:

test/ELF/init-fini.s

@@ -17,11 +17,22 @@
 // RUN: ld.lld -shared %t -o %t2 -init=_foo -fini=_bar
 // RUN: llvm-readobj -dynamic-table %t2 | FileCheck --check-prefix=OVR %s
 
-// Should add a dynamic table entry even if a given symbol stay undefined
+// Don't add an entry for undef. The freebsd dynamic linker doesn't
+// check if the value is null. If it is, it will just call the
+// load address.
 // RUN: ld.lld -shared %t -o %t2 -init=_undef -fini=_undef
 // RUN: llvm-readobj -dynamic-table %t2 | FileCheck --check-prefix=UNDEF %s
-// UNDEF: INIT 0x0
-// UNDEF: FINI 0x0
+// UNDEF-NOT: INIT
+// UNDEF-NOT: FINI
+
+// Don't add an entry for shared. For the same reason as undef.
+// RUN: ld.lld -shared %t -o %t.so
+// RUN: echo > %t.s
+// RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %t.s -o %t2.o
+// RUN: ld.lld -shared %t2.o %t.so -o %t2
+// RUN: llvm-readobj -dynamic-table %t2 | FileCheck --check-prefix=SHARED %s
+// SHARED-NOT: INIT
+// SHARED-NOT: FINI
 
 // Should not add new entries to the symbol table
 // and should not require given symbols to be resolved

test/ELF/resolution-end.s

@@ -0,0 +1,39 @@
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t1.o
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %p/Inputs/resolution-end.s -o %t2.o
+# RUN: ld.lld -shared -o %t2.so %t2.o
+# RUN: ld.lld %t1.o %t2.so -o %t
+# RUN: llvm-readobj -t -s -section-data  %t | FileCheck %s
+# REQUIRES: x86
+
+# Test that we resolve _end to the this executable.
+
+# CHECK:      Name: .text
+# CHECK-NEXT: Type: SHT_PROGBITS
+# CHECK-NEXT: Flags [
+# CHECK-NEXT:   SHF_ALLOC
+# CHECK-NEXT:   SHF_EXECINSTR
+# CHECK-NEXT: ]
+# CHECK-NEXT: Address:
+# CHECK-NEXT: Offset:
+# CHECK-NEXT: Size:
+# CHECK-NEXT: Link:
+# CHECK-NEXT: Info:
+# CHECK-NEXT: AddressAlignment:
+# CHECK-NEXT: EntrySize:
+# CHECK-NEXT: SectionData (
+# CHECK-NEXT:   0000: 80202000 00000000
+# CHECK-NEXT: )
+
+# CHECK:      Symbol {
+# CHECK:        Name: _end
+# CHECK-NEXT:   Value: 0x202080
+# CHECK-NEXT:   Size:
+# CHECK-NEXT:   Binding: Global
+# CHECK-NEXT:   Type:
+# CHECK-NEXT:   Other:
+# CHECK-NEXT:   Section:
+# CHECK-NEXT: }
+
+.global _start
+_start:
+.quad _end

test/ELF/version-script-hide-so-symbol.s

@@ -0,0 +1,28 @@
+# REQUIRES: x86
+
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
+# RUN: ld.lld -shared %t.o -o %t2.so
+# RUN: echo "{ local: *; };" > %t.script
+# RUN: ld.lld --version-script %t.script -shared %t.o %t2.so -o %t.so
+# RUN: llvm-readobj -dyn-symbols %t.so | FileCheck %s
+
+# The symbol foo must be hidden. This matches bfd and gold and is
+# required to make it possible for a c++ library to hide its own
+# operator delete.
+
+# CHECK:      DynamicSymbols [
+# CHECK-NEXT:   Symbol {
+# CHECK-NEXT:     Name: @ (0)
+# CHECK-NEXT:     Value: 0x0
+# CHECK-NEXT:     Size: 0
+# CHECK-NEXT:     Binding: Local
+# CHECK-NEXT:     Type: None
+# CHECK-NEXT:     Other: 0
+# CHECK-NEXT:     Section: Undefined
+# CHECK-NEXT:   }
+# CHECK-NEXT: ]
+
+        .global foo
+foo:
+	nop
+