Remove dead code.

isAlias always returns false and no one is using it. It was
originally added Atom to query if an atom is an alias for another
atom, assuming that alias atoms are different from normal atoms.

We now support atom aliasing, but the way that's implemented is
in a different way than what isAlias assumed. An alias atom is
just a regular defined atom with no content, and it has a layout-
before edge to alias-to atom so that they are layed out at the
same location in the result. So this is dead code, and it doesn't
make much sense to keep it.

llvm-svn: 207884

6 files changed, 0 insertions, 19 deletions

diff --git a/lld/lib/ReaderWriter/CoreLinkingContext.cpp b/lld/lib/ReaderWriter/CoreLinkingContext.cpp
index 0ee4b51af92..36ec7a2ed5c 100644
--- a/lld/lib/ReaderWriter/CoreLinkingContext.cpp
+++ b/lld/lib/ReaderWriter/CoreLinkingContext.cpp
@@ -63,8 +63,6 @@ public:
     return DefinedAtom::permR_X;
   }
 
-  bool isAlias() const override { return false; }
-
   ArrayRef<uint8_t> rawContent() const override { return ArrayRef<uint8_t>(); }
 
   reference_iterator begin() const override {
@@ -128,8 +126,6 @@ public:
     return DefinedAtom::permRW_;
   }
 
-  bool isAlias() const override { return false; }
-
   ArrayRef<uint8_t> rawContent() const override { return ArrayRef<uint8_t>(); }
 
   reference_iterator begin() const override {
@@ -273,4 +269,3 @@ void CoreLinkingContext::addPasses(PassManager &pm) {
 }
 
 Writer &CoreLinkingContext::writer() const { return *_writer; }
-
diff --git a/lld/lib/ReaderWriter/ELF/Atoms.h b/lld/lib/ReaderWriter/ELF/Atoms.h
index 6fec07c18e8..81d1c7ee6f3 100644
--- a/lld/lib/ReaderWriter/ELF/Atoms.h
+++ b/lld/lib/ReaderWriter/ELF/Atoms.h
@@ -381,9 +381,6 @@ public:
     }
   }
 
-  // FIXME: Not Sure if ELF supports alias atoms. Find out more.
-  bool isAlias() const override { return false; }
-
   ArrayRef<uint8_t> rawContent() const override { return _contentData; }
 
   DefinedAtom::reference_iterator begin() const override {
@@ -487,8 +484,6 @@ public:
 
   virtual bool isThumb() const { return false; }
 
-  bool isAlias() const override { return false; }
-
   ArrayRef<uint8_t> rawContent() const override { return _contentData; }
 
   DefinedAtom::reference_iterator begin() const override {
@@ -571,8 +566,6 @@ public:
 
   ContentPermissions permissions() const override { return permRW_; }
 
-  bool isAlias() const override { return false; }
-
   ArrayRef<uint8_t> rawContent() const override { return ArrayRef<uint8_t>(); }
 
   DefinedAtom::reference_iterator begin() const override {
diff --git a/lld/lib/ReaderWriter/Native/ReaderNative.cpp b/lld/lib/ReaderWriter/Native/ReaderNative.cpp
index f338e81ea95..9b8a749aee2 100644
--- a/lld/lib/ReaderWriter/Native/ReaderNative.cpp
+++ b/lld/lib/ReaderWriter/Native/ReaderNative.cpp
@@ -98,10 +98,6 @@ public:
      return (DefinedAtom::ContentPermissions)(attributes().permissions);
   }
 
-  bool isAlias() const override {
-     return (attributes().alias != 0);
-  }
-
   ArrayRef<uint8_t> rawContent() const override;
 
   reference_iterator begin() const override;
diff --git a/lld/lib/ReaderWriter/Native/WriterNative.cpp b/lld/lib/ReaderWriter/Native/WriterNative.cpp
index 5d56c7a295e..80f50e866f4 100644
--- a/lld/lib/ReaderWriter/Native/WriterNative.cpp
+++ b/lld/lib/ReaderWriter/Native/WriterNative.cpp
@@ -431,7 +431,6 @@ private:
     attrs.deadStrip         = atom.deadStrip();
     attrs.dynamicExport     = atom.dynamicExport();
     attrs.permissions       = atom.permissions();
-    attrs.alias             = atom.isAlias();
     return attrs;
   }
 
diff --git a/lld/lib/ReaderWriter/PECOFF/Atoms.h b/lld/lib/ReaderWriter/PECOFF/Atoms.h
index a7477ddffa6..c4ae1271c0b 100644
--- a/lld/lib/ReaderWriter/PECOFF/Atoms.h
+++ b/lld/lib/ReaderWriter/PECOFF/Atoms.h
@@ -105,7 +105,6 @@ public:
     return sectionPositionAny;
   }
   DeadStripKind deadStrip() const override { return deadStripNormal; }
-  bool isAlias() const override { return false; }
 
   Kind getKind() const { return _kind; }
 
diff --git a/lld/lib/ReaderWriter/YAML/ReaderWriterYAML.cpp b/lld/lib/ReaderWriter/YAML/ReaderWriterYAML.cpp
index e9bfc1a8233..dbc50873f75 100644
--- a/lld/lib/ReaderWriter/YAML/ReaderWriterYAML.cpp
+++ b/lld/lib/ReaderWriter/YAML/ReaderWriterYAML.cpp
@@ -892,7 +892,6 @@ template <> struct MappingTraits<const lld::DefinedAtom *> {
     DeadStripKind deadStrip() const override { return _deadStrip; }
     DynamicExport dynamicExport() const override { return _dynamicExport; }
     ContentPermissions permissions() const override { return _permissions; }
-    bool isAlias() const override { return false; }
     bool isGroupChild() const { return _isGroupChild; }
     ArrayRef<uint8_t> rawContent() const override {
       if (!occupiesDiskSpace())