Merge pull request #2 from rust-lang/aix_big

Add support for the AIX Big archive format

Author: bjorn3

Readme.md

@@ -1,6 +1,6 @@
 # A writer for object file ar archives
 
-This is based on commit [8ef3e895a](https://github.com/llvm/llvm-project/tree/8ef3e895ad8ab1724e2b87cabad1dacdc7a397a3) of LLVM's archive writer.
+This is based on commit [8ef3e895a](https://github.com/llvm/llvm-project/tree/3d3ef9d073e1e27ea57480b371b7f5a9f5642ed2) (15.0.0-rc3) of LLVM's archive writer.
 
 ## License
 

src/Alignment.h

@@ -1,4 +1,4 @@
-// Copied from https://github.com/llvm/llvm-project/blob/8ef3e895ad8ab1724e2b87cabad1dacdc7a397a3/llvm/include/llvm/Support/Alignment.h
+// Copied from https://github.com/llvm/llvm-project/blob/3d3ef9d073e1e27ea57480b371b7f5a9f5642ed2/llvm/include/llvm/Support/Alignment.h
 
 //===-- llvm/Support/Alignment.h - Useful alignment functions ---*- C++ -*-===//
 //
@@ -86,6 +86,14 @@ struct Align {
   /// Needed to interact with C for instance.
   uint64_t value() const { return uint64_t(1) << ShiftValue; }
 
+  // Returns the previous alignment.
+  Align previous() const {
+    assert(ShiftValue != 0 && "Undefined operation");
+    Align Out;
+    Out.ShiftValue = ShiftValue - 1;
+    return Out;
+  }
+
   /// Allow constructions of constexpr Align.
   template <size_t kValue> constexpr static LogValue Constant() {
     return LogValue{static_cast<uint8_t>(CTLog2<kValue>())};
@@ -133,7 +141,7 @@ struct MaybeAlign : public llvm::Optional<Align> {
   }
 
   /// For convenience, returns a valid alignment or 1 if undefined.
-  Align valueOrOne() const { return hasValue() ? getValue() : Align(); }
+  Align valueOrOne() const { return value_or(Align()); }
 };
 
 /// Checks that SizeInBytes is a multiple of the alignment.
@@ -175,13 +183,7 @@ inline uint64_t alignTo(uint64_t Size, Align A) {
 inline uint64_t alignTo(uint64_t Size, Align A, uint64_t Skew) {
   const uint64_t Value = A.value();
   Skew %= Value;
-  return ((Size + Value - 1 - Skew) & ~(Value - 1U)) + Skew;
-}
-
-/// Returns a multiple of A needed to store `Size` bytes.
-/// Returns `Size` if current alignment is undefined.
-inline uint64_t alignTo(uint64_t Size, MaybeAlign A) {
-  return A ? alignTo(Size, A.getValue()) : Size;
+  return alignTo(Size - Skew, A) + Skew;
 }
 
 /// Aligns `Addr` to `Alignment` bytes, rounding up.
@@ -208,28 +210,12 @@ inline uint64_t offsetToAlignedAddr(const void *Addr, Align Alignment) {
 /// Returns the log2 of the alignment.
 inline unsigned Log2(Align A) { return A.ShiftValue; }
 
-/// Returns the alignment that satisfies both alignments.
-/// Same semantic as MinAlign.
-inline Align commonAlignment(Align A, Align B) { return std::min(A, B); }
-
 /// Returns the alignment that satisfies both alignments.
 /// Same semantic as MinAlign.
 inline Align commonAlignment(Align A, uint64_t Offset) {
   return Align(MinAlign(A.value(), Offset));
 }
 
-/// Returns the alignment that satisfies both alignments.
-/// Same semantic as MinAlign.
-inline MaybeAlign commonAlignment(MaybeAlign A, MaybeAlign B) {
-  return A && B ? commonAlignment(*A, *B) : A ? A : B;
-}
-
-/// Returns the alignment that satisfies both alignments.
-/// Same semantic as MinAlign.
-inline MaybeAlign commonAlignment(MaybeAlign A, uint64_t Offset) {
-  return MaybeAlign(MinAlign((*A).value(), Offset));
-}
-
 /// Returns a representation of the alignment that encodes undefined as 0.
 inline unsigned encode(MaybeAlign A) { return A ? A->ShiftValue + 1 : 0; }
 
@@ -272,14 +258,6 @@ inline bool operator>(Align Lhs, uint64_t Rhs) {
   return Lhs.value() > Rhs;
 }
 
-/// Comparisons between MaybeAlign and scalars.
-inline bool operator==(MaybeAlign Lhs, uint64_t Rhs) {
-  return Lhs ? (*Lhs).value() == Rhs : Rhs == 0;
-}
-inline bool operator!=(MaybeAlign Lhs, uint64_t Rhs) {
-  return Lhs ? (*Lhs).value() != Rhs : Rhs != 0;
-}
-
 /// Comparisons operators between Align.
 inline bool operator==(Align Lhs, Align Rhs) {
   return Lhs.ShiftValue == Rhs.ShiftValue;
@@ -316,37 +294,6 @@ bool operator>=(MaybeAlign Lhs, MaybeAlign Rhs) = delete;
 bool operator<(MaybeAlign Lhs, MaybeAlign Rhs) = delete;
 bool operator>(MaybeAlign Lhs, MaybeAlign Rhs) = delete;
 
-inline Align operator*(Align Lhs, uint64_t Rhs) {
-  assert(Rhs > 0 && "Rhs must be positive");
-  return Align(Lhs.value() * Rhs);
-}
-
-inline MaybeAlign operator*(MaybeAlign Lhs, uint64_t Rhs) {
-  assert(Rhs > 0 && "Rhs must be positive");
-  return Lhs ? Lhs.getValue() * Rhs : MaybeAlign();
-}
-
-inline Align operator/(Align Lhs, uint64_t Divisor) {
-  assert(llvm::isPowerOf2_64(Divisor) &&
-         "Divisor must be positive and a power of 2");
-  assert(Lhs != 1 && "Can't halve byte alignment");
-  return Align(Lhs.value() / Divisor);
-}
-
-inline MaybeAlign operator/(MaybeAlign Lhs, uint64_t Divisor) {
-  assert(llvm::isPowerOf2_64(Divisor) &&
-         "Divisor must be positive and a power of 2");
-  return Lhs ? Lhs.getValue() / Divisor : MaybeAlign();
-}
-
-inline Align max(MaybeAlign Lhs, Align Rhs) {
-  return Lhs && *Lhs > Rhs ? *Lhs : Rhs;
-}
-
-inline Align max(Align Lhs, MaybeAlign Rhs) {
-  return Rhs && *Rhs > Lhs ? *Rhs : Lhs;
-}
-
 #ifndef NDEBUG
 // For usage in LLVM_DEBUG macros.
 inline std::string DebugStr(const Align &A) {

src/Archive.h

@@ -1,4 +1,4 @@
-// Copied from https://github.com/llvm/llvm-project/blob/8ef3e895ad8ab1724e2b87cabad1dacdc7a397a3/llvm/include/llvm/Object/Archive.h
+// Copied from https://github.com/llvm/llvm-project/blob/3d3ef9d073e1e27ea57480b371b7f5a9f5642ed2/llvm/include/llvm/Object/Archive.h
 
 //===- Archive.h - ar archive file format -----------------------*- C++ -*-===//
 //
@@ -342,6 +342,7 @@ class Archive : public Binary {
 
   Kind kind() const { return (Kind)Format; }
   bool isThin() const { return IsThin; }
+  static object::Archive::Kind getDefaultKindForHost();
 
   child_iterator child_begin(Error &Err, bool SkipInternal = true) const;
   child_iterator child_end() const;
@@ -361,7 +362,7 @@ class Archive : public Binary {
   // check if a symbol is in the archive
   Expected<Optional<Child>> findSym(StringRef name) const;
 
-  bool isEmpty() const;
+  virtual bool isEmpty() const;
   bool hasSymbolTable() const;
   StringRef getSymbolTable() const { return SymbolTable; }
   StringRef getStringTable() const { return StringTable; }
@@ -380,10 +381,10 @@ class Archive : public Binary {
   uint64_t getArchiveMagicLen() const;
   void setFirstRegular(const Child &C);
 
-private:
   StringRef SymbolTable;
   StringRef StringTable;
 
+private:
   StringRef FirstRegularData;
   uint16_t FirstRegularStartOfFile = -1;
 
@@ -393,6 +394,7 @@ class Archive : public Binary {
 };
 
 class BigArchive : public Archive {
+public:
   /// Fixed-Length Header.
   struct FixLenHdr {
     char Magic[sizeof(BigArchiveMagic) - 1]; ///< Big archive magic string.
@@ -413,6 +415,9 @@ class BigArchive : public Archive {
   BigArchive(MemoryBufferRef Source, Error &Err);
   uint64_t getFirstChildOffset() const override { return FirstChildOffset; }
   uint64_t getLastChildOffset() const { return LastChildOffset; }
+  bool isEmpty() const override {
+    return Data.getBufferSize() == sizeof(FixLenHdr);
+  };
 };
 
 } // end namespace object